Cálculo em Serviço: um estudo exploratório

O presente artigo pretende apresentar os resultados de um estudo exploratório, realizado com alunos e professores do curso de Geologia da Unesp – Rio Claro, cujo objetivo foi analisar a relação interesse/ desinteresse e facilidade/ dificuldade dos alunos, em relação ao Cálculo Diferencial e Integral I. Entre as fontes de coleta de dados, estão observações realizadas em sala de aula e entrevistas semi-estruturadas. A análise dos dados apontou alguns problemas relacionados à disciplina, o que permite um melhor entendimento dos fatores que parecem acentuar a insatisfação dos alunos desse curso para com a disciplina

Pollutant dispersion in reservoir's systems : mathematical modelling using numerical simulation and fuzzy sets

Orientadores: Raul Vinhas Ribeiro, João Frederico da Costa Azevedo MeyerTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoResumo: O presente trabalho propõe um método para o estudo da dispersão de poluente num sistema de reservatório, via Modelagem Matemática dos fenômenos principais envolvidos na análise deste tipo de situação. Na modelagem, a opção foi pela clássica Equação Diferencial Parcial de Difusão- Advecção com parâmetros fuzzy reunindo, portanto, aspectos determinísticos e a Lógica Fuzzy de modo a incorporar aspectos característicos e relevantes de dispersão efetiva do poluente, seu transporte e degradação. Condições iniciais e de contorno compatíveis com casos conhecidos são propostas, além de aproximações numéricas adequadamente dimensionadas, via Elementos Finitos, na discretização espacial, com um método de tipo Crank-Nicolson na aproximação temporal. Propõe-se, também, um algoritmo que se preste a simulações computacionais eficientes, em ambiente Matlab. Como estudo de caso, utiliza-se a situação evolutiva do reservatório de Salto Grande, represamento do rio Atibaia, um dos mais importantes mananciais de abastecimento público da região, inserido numa importante região do Estado de São Paulo.Abstract: Current work presents an instrument for dispersion of water's surface pollutant study through Mathematical Modelling and the main phenomenas involved in this type of analysis. For this purpose, we use the Partial Differential Equation of diffusion-advection that incorporates the dispersion accomplish of the pollutant, its transport and decline, with compatible initial and boundering conditions. Numerical approximation well dimensioned are defined and effective computational simulations algorithms, are implemented which considered independent variable, were developed. The independent variable considered can be spatial as well as temporary. As a case study, we use Salto Grande reservoir situation, which is a dike of Atibaia river, one of the most important public water sypply in an important region of São Paulo state. In the descriptive parameters of the problem, the option was the use of fuzzy techniques sets that allow incorporating inherent uncertainties to this situation.DoutoradoAutomaçãoDoutor em Engenharia Elétric

Evolving scenarios of organic matter concentration in alto Tietê basin by mathematical modeling

The water bodies has been suffering with the pollution caused by the disposal of domestic and industrial sewage. The problem is relate, mainly, to the organic matter and scenarios without appropriate treatments become a major problem for the health of society and the environment. Thereby, the present study evaluated the evolutionary framework of the concentration of organic matter in the Tietê river, via mathematical modeling, through values of biochemical oxygen demand. The Tietê river is located in the sub-basin of the Alto Tietê in UGRHI 6, characterized as one of the most polluted rivers in the world and receives large inputs of pollutants by the large number of industries and inhabitants of the region. The model used is based on a system of difference equations and presents, through computer simulations, results that promote relevant discussions in terms of river pollution and indicate that existing discharges, linked to the lack of treatment, act as precursor agent of the quality of the watershed classification and the high levels of pollution in several parts

Water quality of the Atibaia river in the city of Paulínia/SP: evaluation of the Electrical Conductivity and Chloride variables

The present study aimed to evaluate the characteristics that most influenced the water quality variability of the Atibaia river in the city of Paulínia/SP, the coordinates of the water collection point are given by 22º44'23”(S) and 47º07 ' 40 ”(W), in the dry and rainy seasons, from 2006 to 2016. The data used in this study come from the monitoring of parameters carried out in the spring by a research team, accompanied by periodic collections of surface water samples and analyzes laboratory tests. The parameters addressed included: precipitation, temperature, Hydrogenionic potential (pH), turbidity, thermotolerant coliforms (Escherichia coli (E. coli)), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (Ntotal), total phosphorus (Ptotal), total dissolved solids (TDS), electrical conductivity (EC) and chlorides (Cl-). Water quality was assessed using linear correlation analysis, using the Pearson Correlation coefficient (r), and Multivariate Analysis, using Principal Component Analysis (PCA). The presence of EC, Cl- and COD in both periods indicates quality characteristics related to the mineralization of organic compounds present in the water and the eutrophication process