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Estudo da influência da adição de serragem de couro tratada quimicamente nas características de argamassas de cimento Portland
(Universidade Federal de São Carlos, 2009-05-15) Shih, Yung Yuan; Morelli, Márcio Raymundo; https://lattes.cnpq.br/0172837599844991; https://lattes.cnpq.br/2866111560473325
The purpose of this study was to examine the major environmental concern for the large volume of toxic wastes generated by industries of tanneries and the search for a technological solution for the treatment of this waste. The attempt to tie the chromium ion present on residue, shave chrome leather, was used in three steps. In the first step, solutions were prepared with different pHs (acidic, neutral, and basic) and concentrations of residue, obtaining the solution called waste treated . In the second stage, cement pastes were obtained by mixture of the cement Portland, water, and addition of different proportions of waste treated (5 and 10% on the mass of cement). Normal test of consistency, workability, and the set time were applied on these pastes in its fresh state. Also, the pHs of the paste were evaluated to verify the influence of it on setting time. Finally, in the third stage, samples were prepared using mortar and after 28 days were physically characterized and tested for axial compressive strength. The most promising compositions were subjected for the structural characterization for analysis of the phases formed (DRX) and the microstructure (MEV / EDS). The results show that the reagents used for the pre-treatment of the residue are effective, but it causes some decrease of the mechanical strength of the mortar. The pHs of the waste treated do not modify that much on characteristic of the paste and mortar on the fresh and hardened state. It is expected that these results will contribute a solution to an environmental problem of a very important sector for Brazilian companies, which is industries of tannery for the production of leather.
Avaliação ecotoxicológica da adição de nitrato em sedimentos eutrofizados da Represa Ibirité (Betim MG): experimentos em microcosmos
(Universidade Federal de São Carlos, 2009-05-15) Janke, Helena; Mozeto, Antonio Aparecido; https://lattes.cnpq.br/5060724013325772
The objective of the present dissertation was to make a toxicity assessment of the application of calcium nitrate solution as a remediation procedure for sediments of a eutrophic aquatic ecosystem. The study was carried out using microcosms with superficial sediments and water from sediment-water interface of the Ibirité Reservoir located in the metropolitan area of Belo Horizonte (Minas Gerais, SE Brazil). The experiment lasted 135 days and the following treatment or incubation periods were applied: t=0, t=5, t=10, t=25, t=50, t=85 and t=135 days. In each period, one controlmicrocosm and three treatment-microcosms were disassembled and, chemically and ecotoxicologically analyzed. The organisms Ceriodaphnia silvestrii and Vibrio fischeri (Microtox® System) were used for the acute toxicity assessment of the water from sediment-water interface and the pore water of sediments, whereas the organism Chironomus xanthus was used for the toxicity assessment of bulk sediment. The toxicity tests were run in parallel with chemical analyzes of dissolved inorganic nitrogen species (nitrate, nitrate and ammonium), sulfate, and metals in the interface sediment-water and interstitial water samples. Acid volatile sulfide (AVS), simultaneously extracted metal (SEM) and potentially bioavailable metals were analyzed in bulk sediment. The overall results indicate that nitrate whose concentration reached 1,200 mg N-NO3 - L-1 in sediment pore water samples from treatment-microcosms is the most probable compound causing toxicity to the tests organisms. For Chironomus xanthus sediments were deleterious to the exposed organisms in all microcosm run, except in the period of t= 135 days. For the experimental conditions of this work, the application of calcium nitrate as a remediation procedure for sediments from Ibirité Reservoir indicated to be inadequate from the ecotoxicological pint of view.
A midiatização das patentes sob o olhar CTS (Ciência, Tecnologia e Sociedade)
(Universidade Federal de São Carlos, 2009-05-15) Mazocco, Fabricio José; Sousa, Cidoval Morais de; https://lattes.cnpq.br/0573233540937425; https://lattes.cnpq.br/7934562455367253
This paper intends to study patents as a media information source. This research identified the characteristics of this techno-scientific product that somehow calls press media s attention; also, it aims to set discussions on the relation between media and patents from STS studies (Science, Technology and Society). It took as empirical object the newspapers Gazeta Mercantil (GM) and Valor Econômico (VE). All news about patents, involving aspects such as legal issues involving patents protection, patents seen as an innovation sign, patent as an instrument for Science and Technology (S&T) construction, patents system, technical details about patents, and others. This paper starts in a presumption: mass media still approach patents in an economical way and follows offer-line model logics in this way, basic research is followed by applied research and later by technological development that allows new products and society benefits. Methodology of content analysis was used on news about patents. It was verified that patents, a product of techno-science, has elements to make it a precious source of information to mass media. When dealing with the necessary requirements in order to patent any innovation, foreseen in law, we stand out the importance to divulge it, in order to spread not only technical issues but also social elements.