Aline Pimentel Gomes

Avaliação de um método baseado em análise de imagens para obtenção de parâmetros de forma em grãos de areia de britagem

The objective of this paper is to evaluate a method based on image analysis to obtain shape parameters in crushed sand grains. There is no consensus about standards and rules for testing aggregates, the lack of methodology to prepare and conduct tests may produce incorrect results, which do not satisfactorily represent the aggregate characteristics. One way to perform these analyzes is the use of images obtained with magnifying glasses or similar equipment. To contribute to this, three experiments were prepared with samples of crushed sand from the city of Passo Fundo. The fixed and evaluated parameters were: samples preparation, zoom used for image acquisition and number of grains representative of the shape parameters. The results were statistically analyzed and significant differences were obtained to the shape factor regarding the fixed parameters, except for the number of grains needed to characterize it, which differs from the currently literature used by academic studies. According to this work it is possible to realize that it is necessary to standardize the tests for shape analysis to eliminate errors generated by the interpretation of incorrect results, which may have been generated by changes in the methodology for conducting the tests.

ANÁLISE DA VIABILIDADE ECONÔMICA DO PROCESSO DE PIRÓLISE PARA TRATAMENTO DE RESÍDUOS SÓLIDOS URBANOS: ESTUDO DE CASO APLICADO A UMA CIDADE DE MÉDIO PORTE

Find new solutions for the treatment of municipal solid waste is a challenge of modern society. The fast pyrolysis process arises as an alternative, besides generating by-products of commercial value. The general objective of this work is to evaluate the economic viability of the pyrolysis process for treatment of municipal solid waste (MSW) applied to a medium-sized town. To meet the overall objective were determined specific objectives who understood the locational alternatives study and methods of investment analysis provided certainty, uncertainty, and risk analysis. The pyrolysis process for MSW was attractive due to high operating costs and taxes on the sale of electricity and fertilizer. The Net present value-NPV resulting cash flow is negative and there is no return on capital invested, for both the enterprise and the investors cash flow. In this case, the research has enabled the study of vario us scenarios for economic viability of the project through sensitivity analysis. Considering the possibility of integration with more municipalities to supplement the volume of raw material, reducing the cost of transport of MSW pyrolysis plant and even th e increase in the price of electrical energy for sale, or tax exemption, the project is a cost effective alternative, while in addition to the economic benefits, the pyrolysis plant enables the Elimination of environmental liabilities generated by landfill s.