Equações diferenciais ordinárias não suaves autônomas e não autônomas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo sobre o uso de agregados reciclados na composição de concretos e argamassas

Two of the major problems caused by construction activity are the production of construction and demolition waste (CDW) and the exploitation of mineral resources, causing big impacts on the environment. Therefore, the recycling has been shown as an alternative to mitigate the harmful effects of waste on the urban environment and prevent the exploitation of new raw materials. This course work aims to study the behavior of recycled aggregates from Vale do Paraíba in concrete and mortar. Initially, it presents the definitions of recycled aggregates according to CONAMA Resolution No. 307/2002, the aggregate settings for concrete and mortar (such as the grain size, its origin and density, and the characterization parameters according to ABNT), and the definition of ACI method of concrete mix design. Afterwards, it presents the characterization of materials separated by assays. After that, it shows the theoretical concrete proportioning applying the ACI method and experimental concrete proportioning. Then, the analysis of results is performed to finally conclude that the materials provided can't be used to replace natural aggregates because they cannot have the same performance. With the studies, it could be observed that the recycled aggregate presents a great complexity and diversity in origin, therefore the form how the material should be handled requires great care

Geração de simuladores de filas para diferentes contextos com estudo de casos para redes de computadores

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Procedimento para homologação de sistemas ecoeficientes para obtenção de créditos de carbono

This paper deals with the homologation process for obtaining carbon credits through the Clean Development Mechanism (CDM), that regulates the greenhouse gases reductions under the rules of the Kyoto Protocol. The CDM evaluates projects through a project cycle, which begins with the preparation of the Project Design Document (PDD) until the project certification to receive Certified Emission Reductions (CERs), popularly known as carbon credits. This study analyzed the implementation of the system Burner Recorder System for Low Flows of Biogas (QRBBV), developed by Marcelino Junior & Godoy (2009), in an eco-friendly wastewater treatment mini-plant (miniEETERA), built at the site of UNESP - Guaratinguetá SP. The QRBBV system is low cost and high reliability, developed to burn the methane generated at sites of low and variable production of biogas, which is not economically justified their energy recovery. Currently, almost all wastewater generated at the site of the campus is being treated by miniEETERA and, as a result, the biogas originated by this activity is being released into the atmosphere. Therefore, the project activity aims to capture and burn the biogas generated by miniEETERA, reducing the negative effects caused by the methane emissions into the atmosphere and, thus, claim to receive carbon credits. This work aimed to demonstrate the project applicability under CDM through the study and preparation of the PDD, as well as an analysis of the entire project cycle required for homologation. The result of the work obtained an estimate of only 20 CERs per year and proved to be economically unviable for approval through the CDM, since the spending with the approval process would not be compensated with the sale of CERs, mainly due the low carbon price in the world market. From an environmental standpoint, the project is perfectly... (Complete abstract click electronic access below)