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Avaliação do potencial de corrosão de armaduras em concretos com substituição parcial do agregado miúdo pela areia de cinza do bagaço da cana-de-açúcar - ACBC
(Universidade Federal de São Carlos, 2013-01-25) Almeida, Fernando do Couto Rosa; Sales, Almir; https://lattes.cnpq.br/7377787166073311; https://lattes.cnpq.br/2303805462606634
Brazil is the world's largest producer of sugarcane and the leading exporter of its derivatives (sugar, alcohol, energy etc.). One of the main waste generated in the manufacturing process of this sector is the sugarcane bagasse ash sand (SBAS), produced from the burning of bagasse into boilers to produce electricity (cogeneration). This ash sand is composed of a high amount of silica and it is also currently discarded in cane plantations as organic fertilizer, despite the fact that it is poor in nutrients. This research proposes to provide an alternative application of SBAS in concrete as a replacement material for fine aggregate. Furthermore, the durability of concrete with alternative materials demands a special attention, especially regarding reinforcement corrosion. This is a major concern of the use of wastes on the degradation of concrete structures. The process begins with the despassivation of steel reinforcement, and it propagates in a suitable environment. The aim of this study was to evaluate the potential occurrence of reinforcement corrosion in concrete made with SBAS as a partial replacement material for fine aggregate. The ash sand samples were collected in a plant in the State of São Paulo, and standardized through a sieving and grinding. The SBAS was subjected to physical and chemical characterization, by its chemical composition, sieve analysis, powdery material, absorption, bulk density and true density. Mortars and concretes were produced with levels of substitution of 0% (reference), 30% and 50% of SBAS. In mortars, tests of compressive strength, porosity (void index and pores analysis by optical microscopy), water absorption, accelerated carbonation, chloride penetration and electrical conductivity of the aqueous solution were performed. The concretes were submitted to tests of compressive strength, void index, absorption, chloride penetration, potential and rate of reinforcement corrosion. Thus, the results indicated that substitution of 30% and 50% by SBAS can increase the compressive strength of concrete and the resistance to attack by chlorides, and decrease the despassivation probability of reinforcement. However, with the content of 50% of SBAS, the corrosion rate was significantly higher in comparison to other samples, and it was similar between the concretes with 30% of SBAS and reference. Thus, it was possible to conclude that the concrete with 30% of SBAS as a substitute of fine aggregate may be applied in conventional structural elements without loss of mechanical and durability performance.
Indicadores de circulação do acervo na Biblioteca Comunitária da UFSCar
(Universidade Federal de São Carlos, 2013-01-25) Ninin, Débora Marroco; Amaral, Roniberto Morato do; https://lattes.cnpq.br/6958372164719600; https://lattes.cnpq.br/0665489360444494
The emergence of new technologies and process automation of libraries and information centers open new possibilities for studies of uses and users within these environments. The aim of this study was to know the users' reading behaviors and how these behaviors are related to each other, based on records from the library home loans. The research method was the case study, the unit should the Community Library of Federal University of São Carlos, São Carlos campus. The techniques used was the analysis bibliometric of information and analysis of social networks, with support from VantagePoint® software. The data sample analyzed comprised 119,720 records related to the circulation (borrowing, renewal and reserves) of the collection in 2011. The results were prepared and analyzed indicators on the use of the acquis by the community: 1] Indicators related to movement; 2] Indicators on lending activity; 3] Indicators on lending activities of the Literature; 4] Indicators on the lending activities of the collection of Library and Information Science; 5] Indicators on renovation activity, and 6] Indicators on the activity of booking. Based on the obtained results it can be stated that the use of bibliometrics for conducting user studies predicted by the theory of studies of uses and users, was efficient in developing a set of indicators for the profile of users and uses of the collection, in an automated method and without direct contact with users. It was also possible to reaffirm the importance of studies of uses and users through a quantitative approach with new information technologies that open up new possibilities for this type of study.
Ensino de LE em ambientes virtuais: um estudo sobre os tipos de interação e de andaimes presentes na construção de conhecimento em língua espanhola
(Universidade Federal de São Carlos, 2013-01-25) Tomazella, Carla Maluf; Gregolin, Isadora Valencise; https://lattes.cnpq.br/1015869228676997; https://lattes.cnpq.br/5270328580071718
La difusión y proliferación del uso didáctico de ordenadores conectados a Internet han proporcionado un nuevo contexto de acción para los profesores de idiomas. En este nuevo panorama, las clases en el aula no consisten en el único espacio de interacción de los cursos y muchos profesores utilizan también Entornos Virtuales de Enseñanza- Aprendizaje (EVE/A) como apoyo y complementación al trabajo que desarrollan en la modalidad presencial. En rechazo a la práctica de transponer el modelo de enseñanza presencial a los medios digitales, los expertos sugieren que la adopción de nuevas tecnologías en el aula debe basarse en prácticas pedagógicas apropiadas a este contexto (KENSKI, 2008; SILVA, 2003). El interaccionismo social de Vigotsky (1988) se encuentra en la base de la pedagogía de la enseñanza ministrada en entornos virtuales de enseñanza-aprendizaje por defender que la construcción del conocimiento está condicionada a la mediación social - que, a su vez, ocurre a través de la lengua en interacción. Esta investigación se centra en el estudio de las interacciones que ocurren en los foros en línea de un curso de Español para Turismo - ofrecido en la modalidad a distancia en el entorno virtual Moodle. Su objetivo es problematizar la influencia de los andamios (WOOD, BRUNER, ROSS, 1976) en la construcción del conocimiento en lenguas extranjeras. Esta es una investigación cualitativa y interpretativa, cuyos análisis se basan en estudios sobre la interacción en foros en línea (PAIVA y RODRIGUES JR., 2004; LUCENA FILHO y OLIVEIRA, 2006; GREGOLIN, 2008) y sobre la enseñanza mediada por nuevas tecnologías (KENSKI, 2008; BARBERÁ, 2006). Nuestro objetivo fue comprender el funcionamiento de los foros, delimitando los tipos de andamios más recurrentes y sus funciones en el contexto de un curso de español para el turismo. También se buscó, a través de la investigación, aportar datos que puedan contribuir en la formación de profesionales capaces de actuar en el escenario educativo que se define a partir de la masificación del uso de las nuevas tecnologías. Los resultados mostraron un amplio uso de ayudas pedagógicas o andamios por el profesor y por los propios estudiantes, lo que explicita el papel fundamental de los foros en línea como un lugar de socialización y nos permite concluir que la educación virtual basada en la interacción es capaz de impulsar el desarrollo de los aprendices en la construcción de conocimiento en lengua extranjera, potencializando los espacios de interacción de los cursos.