Lorscheitter M.L.,Federal University of Rio Grande do Sul |
Roth L.,Cientec Inc.
Anuario do Instituto de Geociencias | Year: 2013
The palynology of sedimentary profiles aiming palaeoenvironmental reconstructions require quantitative analysis, so that the environment can be inferred from the palynomorphs. The percentage of pollen grains in each taxon, in relation to the total counted in the sample is largely used in this study, but often can significantly distort the results because it is a relative analysis. The absolute analysis of pollen concentration can correct these distortions, and should also be included in the methodology to ensure more reliable results. Source
Fae Gomes G.M.,Cientec Inc. |
Fae Gomes G.M.,University of the Rio dos Sinos Valley |
Philipssen C.,Federal University of Rio Grande do Sul |
Bard E.K.,Cientec Inc. |
And 2 more authors.
Journal of Environmental Chemical Engineering | Year: 2016
Rice husk combustion generates ashes that consist basically of SiO2 and can be used in several and important applications on its amorphous form. When using bubbling fluidized bed combustion for rice husk ash generation, process variables, like temperature, fluidization velocity, combustion efficiency and elutriation behavior, influence ashes characteristics for synthesis step as well as silica purity. In this way, this work analyses the relations among rice husk fluidized bed hydrodynamics and combustion variables, rice husk ashes' characteristics and yield of silica synthesis according to ashes purification. Rice husk combustion was applied in a 250 kWth bubbling fluidized bed pilot plant on temperatures of 700, 750, 800 and 850 °C together with fluidization velocities of 0.3, 0.4 and 0.5 m/s. One bench scale fluidized bed was also used to observe elutriation behavior. Rice husk ashes were characterized according to their crystallinity, particle diameter and composition. Silica was synthesized with NaOH impregnation from the different ashes, without purification, with acid purification and water purification. Low carbon content, up to 1.89%, was obtained in the combustion ashes. Combustion efficiency increased with combustion temperature but showed some decrease tendency as fluidization velocity increases. Rice husk ash crystallinity showed values up to 15.7%, which was associated with the presence of quartz and attributed to rice husk contamination, not with bed elutriation. Concerning silica yield, the three different purification procedures prior to NaOH impregnation, although presenting different carbon removals on ash, statistically did not show different values. © 2016 Published by Elsevier Ltd. Source
Fae Gomes G.M.,Cientec Inc. |
Fae Gomes G.M.,Federal University of Rio Grande do Sul |
Encarnacao F.,Associacao Riograndense de Empreendimentos de Assistcncia Tecnica e Extensao Rural EMATER RS
Environmental Research | Year: 2012
Black wattle silviculture is an important activity in southern Brazil. Much of the wood is used in the production of charcoal and the pyrolysis products impacts on air quality. This paper estimates the level of atmospheric contamination from the production of charcoal in one region of Brazil. We describe a low-cost charcoal kiln that can capture condensable gases and we estimate the levels of exposure of kiln workers to carbon monoxide. The latter results indicated that exposure to carbon monoxide can be reduced from an average of 950. ppm to 907. ppm and the mass of gases reduced by 16.8%. © 2012 Elsevier Inc. Source
Nitzke J.A.,Federal University of Rio Grande do Sul |
Cladera F.,Federal University of Rio Grande do Sul |
Thys R.,Federal University of Rio Grande do Sul |
da Cruz F.T.,Federal University of Rio Grande do Sul |
Martinelli S.,Cientec Inc.
Food Science and Technology | Year: 2016
The 5° Simpósio de Segurança Alimentar (5th Food Safety and Security Symposium) was held in May, 2015, in Bento Gonçalves, RS, Brazil with the objective of discussing the interrelation between food and health, in various perspectives. This paper reviews the state of the art regarding all the issues discussed during the Symposium, connecting them with the lectures presented at the conference. As final remarks, it was perceived that the interrelation between food and health is growing stronger and cannot be discussed without involving the different areas involved. © 2016, Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA. All rights reserved. Source
Susin R.C.,Fundacao de Ciencia E Tecnologia CIEN TEC |
Mior R.,Fundacao de Ciencia E Tecnologia CIEN TEC |
Da Costa Dias V.M.,Cientec Inc.
Brazilian Journal of Food Technology | Year: 2015
Chocolate consumption is usually associated with enjoyment, milk chocolate desserts being a very popular choice. Besides, the literature provides data suggesting health benefits for chocolate products as compared to non-chocolate candies. However, the lipid composition of cocoa and its commercial products has yet to be completely elucidated and understood, although much research has been carried out with this objective. Contributions to this objective frequently face difficulties in the field of Analytical Chemistry due to the complexity of the composition of such a food. On the other hand, the sodium content of foods is currently a major concern. Thus, this work aims to provide information concerning the composition of commercial milk chocolate in terms of its fatty acid profile and sodium content. To achieve this purpose, analytical adjustments and improvements to the methodology were made and described in this paper. Sodium (FAAS) and a total of 50 fatty acids (GC-FID) were determined in eight samples of milk chocolate bars from different manufacturers. The samples were purchased from retailers in Porto Alegre - Brazil. In the determination of the fatty acids, possible losses during methylation deserved special attention and were studied. Nevertheless, large differences were not found in comparison with the nutritional facts declared on the label. However, the results obtained for sodium demonstrated the importance of food inspection, considering the discrepancies found. Source