Navegando por Data de Publicação, começando com "2006-07-31"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 2 de 2

Rodovias em áreas urbanizadas e seus impactos na percepção dos pedestres
(Universidade Federal de São Carlos, 2006-07-31) Silva Junior, Sílvio Barbosa da; Ferreira, Marcos Antonio Garcia; https://lattes.cnpq.br/2643134259454260; https://lattes.cnpq.br/8480076142039633
This work presents the results of a opinion poll, applied to the inhabitants of an urban area along the BR-050 highway, in Uberlândia MG, carried out to estimate the importance of the impacts originated by the Barrier Effect and its characterization attributes. The Barrier Effect refers to the motorized transportation infrastructure impacts over the non-motorized transport. The method applied to this survey to determine the importance degree of each variable and its attributes of characterization related to the Barrier effect consists of a questionnaire, elaborated according to the Likert recommendations, and with the utilization of the Successive Intervals Method to determine the distance of the elements of a scale. The method which has been considered appropriate and easy to apply, produced satisfactory elements to the proposed analysis. The results show that the highway, inserted in a urban site, limitate the on foot transport for the inhabitants of the surroundings of the highway (effects), resultants of the Barrier Effect. It also was possible to identify the importance of defining attributes of each limitation (causes).
Avaliação da resistência mecânica de argamassas de cimento Portland contendo serragem de couro tratada em meio ácido
(Universidade Federal de São Carlos, 2006-07-31) Silva, André Luiz Ribeiro Tachard da; Morelli, Márcio Raymundo; https://lattes.cnpq.br/0172837599844991
Suitable destination of industrial solid wastes that have not well established or completely successful mitigation techniques is nowadays a fundamental important subject, all over the world. In Brazil, one of the most pollution-intensive industries is the tanning skin and processing leather industry. Among its wastes, there is a hazardous chromium-containing waste, named leather shaving, which needs technological alternatives to reintegrate its great quantity generated to materials life cycle. Based on materials engineering concepts, and from the experiences related in bibliography, this work proposes the leather shaving dissolution in phosphoric acid and later incorporation of this new product in Portland cement mortar; changes on the strength of mortar are very important, being the focus of this work. Mortars and cement pastes were made to serve as standards, and treated waste-containing samples were produced to compare the results and to try explaining their causes. The analysis of the experimental results shows that treated leather shaving addition inhibits hydration of Portland cement compounds, due to the phosphoric acid; this retard is disclosed by the increased paste setting time and the mortar mechanical strength development after 91 days, this strength is close to the standard sample one. Porosity remained almost unaltered, and the main microstructural change found was the calcium phosphate phase formation, detected by XRD and SEM. At last, cement matrix was effective at fixing chemically Cr (III), an important result in view of environmental aspects.