Use of mathematical models in the study of bodily growth in GIFT strain Nile tilapia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mathematical modeling and analysis of the flocculation process in chambers in series

In this study, the flocculation process in continuous systems with chambers in series was analyzed using the classical kinetic model of aggregation and break-up proposed by Argaman and Kaufman, which incorporates two main parameters: K (a) and K (b). Typical values for these parameters were used, i. e., K (a) = 3.68 x 10(-5)-1.83 x 10(-4) and K (b) = 1.83 x 10(-7)-2.30 x 10(-7) s(-1). The analysis consisted of performing simulations of system behavior under different operating conditions, including variations in the number of chambers used and the utilization of fixed or scaled velocity gradients in the units. The response variable analyzed in all simulations was the total retention time necessary to achieve a given flocculation efficiency, which was determined by means of conventional solution methods of nonlinear algebraic equations, corresponding to the material balances on the system. Values for the number of chambers ranging from 1 to 5, velocity gradients of 20-60 s(-1) and flocculation efficiencies of 50-90 % were adopted.

The first frequency of cantilevered bars with geometric effect: a mathematical and experimental evaluation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A genetic algorithm/mathematical programming approach to solve a two-level soft drink production problem

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The influence of floc size and hydraulic detention time on the performance of a dissolved air flotation (DAF) pilot unit in the light of a mathematical model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A mathematical approach to simulate spatio-temporal patterns of an insect-pest, the corn rootworm Diabrotica speciosa (Coleoptera: Chrysomelidae) in intercropping systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Um Estudo da modelagem matemática na educação matemática e seu potencial para o desenvolvimento do pensamento crítico

The implementation of mathematical modeling curricula represents a great challenge, both for teachers and students, since it escapes the traditional teaching methodology, i.e. when the teacher speaks to his/her students. This work presents, at least, one possible way of implementing mathematical modeling inside the classroom, and how this way encourage critical thinking in students. I see mathematical modeling as an opportunity to minimize student's rejection and increase their interest for mathematics, promoting their competencies to give points of scene in every day situations. The history of mathematics shows that mathematical modeling had developed since almost the beginning of human live, when men needed to solve problems that arose in the course of his life. Mathematics has become more and more abstract, but it is important to recall what was originated it. In this way, it is possible to make this subject matter more meaningful to students. I will make an introduction of mathematical modeling, presenting some important definitions. Based on this framework, I will present a classroom instruction understand on a 7 th grade classroom by myself. With this in instruction I sustain the idea that mathematical modeling has, in fact, a great potential to improve the quality of mathematics teaching. I also sustain that, the development of critical thinking, as a competence, way be achieved with it

O ensino de geometria através da pavimentação do plano

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mathematical modeling of a continuous alcoholic fermentation process in a two-stage tower reactor cascade with flocculating yeast recycle

Experiments of continuous alcoholic fermentation of sugarcane juice with flocculating yeast recycle were conducted in a system of two 0.22-L tower bioreactors in series, operated at a range of dilution rates (D (1) = D (2) = 0.27-0.95 h(-1)), constant recycle ratio (alpha = F (R) /F = 4.0) and a sugar concentration in the feed stream (S (0)) around 150 g/L. The data obtained in these experimental conditions were used to adjust the parameters of a mathematical model previously developed for the single-stage process. This model considers each of the tower bioreactors as a perfectly mixed continuous reactor and the kinetics of cell growth and product formation takes into account the limitation by substrate and the inhibition by ethanol and biomass, as well as the substrate consumption for cellular maintenance. The model predictions agreed satisfactorily with the measurements taken in both stages of the cascade. The major differences with respect to the kinetic parameters previously estimated for a single-stage system were observed for the maximum specific growth rate, for the inhibition constants of cell growth and for the specific rate of substrate consumption for cell maintenance. Mathematical models were validated and used to simulate alternative operating conditions as well as to analyze the performance of the two-stage process against that of the single-stage process.

Notes on competencies in engineering education

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Informatics competencies in nursing management

This study aimed to identify in scientific literature the informatics competencies required from the nurses to make decision in management process. Through a scoping review, literature databases were searched to find articles published in Portuguese, English, or Spanish, until July 2013. 188 articles were found, and seven were included in this study, published between 1994 and 2011. The studies were written in English (5; 71%), in USA (5; 71%), using experience reports or literature review designs (5; 71%). The informatics competences were categorized according the Technology Informatics Guiding Education Reform (TIGER). The findings highlight gaps in informatics competence to make decisions in the management process--essentially in information management competence.

A mathematical view of water table fluctuations in a shallow aquifer in Brazil

Detailed monitoring of the groundwater table can provide important data about both short- and long-term aquifer processes, including information useful for estimating recharge and facilitating groundwater modeling and remediation efforts. In this paper, we presents results of 4 years (2002 to 2005) of monitoring groundwater water levels in the Rio Claro Aquifer using observation wells drilled at the Rio Claro campus of São Paulo State University in Brazil. The data were used to follow natural periodic fluctuations in the water table, specifically those resulting from earth tides and seasonal recharge cycles. Statistical analyses included methods of time-series analysis using Fourier analysis, cross-correlation, and R/S analysis. Relationships could be established between rainfall and well recovery, as well as the persistence and degree of autocorrelation of the water table variations. We further used numerical solutions of the Richards equation to obtain estimates of the recharge rate and seasonable groundwater fluctuations. Seasonable soil moisture transit times through the vadose zone obtained with the numerical solution were very close to those obtained with the cross-correlation analysis. We also employed a little-used deep drainage boundary condition to obtain estimates of seasonable water table fluctuations, which were found to be consistent with observed transient groundwater levels during the period of study.

Theoretical approaches to forensic entomology: I. Mathematical model of postfeeding larval dispersal

An overall theoretical approach to model phenomena of interest for forensic entomology is advanced. Efforts are concentrated in identifying biological attributes at the individual, population and community of the arthropod fauna associated with decomposing human corpses and then incorporating these attributes into mathematical models. In particular in this paper a diffusion model of dispersal of post feeding larvae is described for blowflies, which are the most common insects associated with corpses.