37 research outputs found
Phenolic compounds, methylxanthines and antioxidant activity in cocoa mass and chocolates produced from "witch broom disease" resistant and non resistant cocoa cultivars
Fauna helmintológica de ovinos provenientes da microrregião de Jaboticabal, estado de São Paulo, Brasil
Adenoviruses isolated from civilian and military personnel in the city of Rio de Janeiro, Brazil
Structural changes and degradation of Red Latosols under different management systems for 20 years
A parasitological paradox: Why is ascarid infection so rare in the prehistoric Americas?
Trilhas e seu papel ecológico: o que temos aprendido e quais as perspectivas para a restauração de ecossistemas?
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Comparative Study Of Simulations And Experimental Results Of Biodiesel Production Using Two Types Of Reactive Distillation Columns
This work presents the biodiesel production from soybean oil with bioethanol from sugar cane in presence of sodium hydroxide as catalyst. The purpose of the present work is to show a comparative study, simulation and experiments, of an efficient process using reactive distillation (RD) columns applied to biodiesel production. Two systems were used in order to present the most efficient process. The main equipments of the first system were a pre-reactor (batch stirred tank reactor: BSTR) and a packed RD column filled with glass rings and the second system were a pre-reactor (plug flow reactor: PFR) and a RD column with ten plates.Experimental design was used in order to optimize the process variables of biodiesel production and the best ester (biodiesel) conversion was 99.84 wt.% after 6 minutes of reaction, obtained with the RD sieve tray column. Simulations of both RD columns were carried out in Aspen Plus software and these simulations are in agreement with experimental results. © 2012 Elsevier B.V.30108111Knothe, G., (2010) Progress in Energy and Combustion Science, 36, pp. 364-373Qiu, Z., Zhao, L., Weatherley, L., (2011) Chem. Eng. Proc.: Process Intensification, 49, pp. 323-330Da Silva, N.L., Garnica, J.A.G., Batistella, C.B., Wolf Maciel, M.R., Maciel Filho, R., (2011) Bioresource Technology, 102, pp. 2672-2677Gomez-Castro, F.I., Rico-Ramirez, V., Segovia-Hernandez, G.J., Hernandez-Castro, S., (2010) Chemical Engineering Research & Design, 89, pp. 480-490He, B.B., Singh, A.P., Thompson, J.C., (2005) Transactions of the ASAE, 48 (6), pp. 2237-2243Da Silva, N.L., Santander, C.M.G., Batistella, C.B., Wolf Maciel, M.R., Maciel Filho, R., (2011) Appl. Biochem. Biotechnol., 161, pp. 245-254Kister, H.Z., (1992) Distillation Design, , McGraw-Hill, United States, Chapter 9: Packing Effficiency ScaleupBaur, R., Krishna, R., (2002) Chenmical Enginering and Precessing, 41, pp. 445-462Kuramochi, H., Maeda, K., Kato, S., Osako, M., Nakamura, K., Sakai, S., (2009) Fuel, 88, pp. 1472-1477Noureddini, H., Zhu, D., (1997) Journal of the American Oil Chemists' Society, 74, pp. 1457-146
Recovery Of Degraded Areas Using Topsoil In The Amazon Rainforest
This study is aimed at evaluating the effect of placing the top soil cover areas, such as tailings degraded by tin mining, in the Amazon rainforest in Brazil. The evaluations of the planting sites occurred in areas where tin mining was carried out, basically planting native trees over a period of seven years. This work did not come from a pre-decreed methodology of experimental design, and data was collected only seven years after planting. Thus, it was not possible to identify all variables that contributed to a better recovery of the areas. Sampling was done about seven years after placing the " top soil " and is determined: pH, organic matter content, P, K, Ca, Mg, Al, cation exchange capacity (T), base saturation (V%), B, Fe, Zn, Cu and Mn. The native forest species existing at the site were evaluated in relation to height (in meters) and diameter of the base. For all sites where the surface layer of soil was applied, there were significant differences in the growth of native species. A fundamental aspect in the rehabilitation of areas degraded by mining, in general, is the knowledge about the soil where that recovery must be conducted. The specific procedures in the rehabilitation of those areas depend essentially on the physical, chemical, biological and mineralogical properties of the soil, which must present conditions for the adequate development of the plants. The initial idea of implanting a project of recovery of soils degraded by mining in the Amazon Forest emerged from a first visit to the field, carried out in 1998. The conditions of the already mined areas, in comparison to the exuberant forest of the surroundings caught our attention. The mining company that acts in the area had already been trying for some time to implant a plan of recovery of these mining areas, however without reaching any significant positive results. The loss of organic matter is one of the main problems of degraded areas in Brazil. The storage and reuse of a blanket of soil (topsoil) produce excellent results, but most of the miners consider this technique expensive and difficult because of operational costs and the sharp topographical condition of the mine site. Therefore, a research project was elaborated prioritizing the recovery of the soil degraded by the tin mining as a prior step to the recovery activities with native forest species. The formation of a superficial pseudo-horizon that supported the vegetation and the time that it would take for its establishment became the main objective of this research. The objective of this work is to verify the levels of elements and their traces in areas where top soils were applied for the remediation of degraded areas with local re-vegetation. © 2011 WIT Press.167481485Fontes, M.P.F., Estudo pedológico reduz impacto da mineração (1991) Revista Da Cetesb De Tecnologia, pp. 58-61. , AMBIENTE, São PauloRibeiro, Admilson, I., (2005) Mecanização Do Preparo De Solo Em Áreas Degradadas Por Mineração Na Floresta Do Jamari, p. 135. , Rondônia, Brasil. FEAGRI, UNICAMP, Campinas-SP, (Tese de doutoradoVance, E.D., Brookes, P.C., Jenkinson, A.S., Na extraction method for measuring soil microbial biomass C (1982) Soil Biologic Biochemical, Oxford, 19, pp. 703-707Banzatto, D.A., Kronka, S.N., (1992) Experimentação Agrícola, p. 247. , 2.ed. Jaboticabal: Ed. Fune