Anomalous flow behaviour of bauxite tailings

This paper deals with the anomalous flow behaviour observed in two bauxite tailings pumping systems, with 450 mm and 680 mm outer diameter. In order to enlarge the pipeline lengths in the field, tests were carried out in a laboratory test-loop in order to try to understand the anomalous (intermittent) flow behaviour and to solve the problem. Based on data obtained from these laboratory tests and using a generalized REYNOLDS number it was possible to obtain results that fit the MOODY ROUSE diagram.

Global analysis of aerodynamics deflectors efficiency in the grinding process

The conventional, grinding methods in some cases are not very efficient because the arising of thermal damages in the pieces is very common. Optimization methods of cutting fluid application in the grinding zone are essential to prevent thermal problems from interaction of the wheel grains with the workpiece. surface. The optimization can happen through the correct selection of the cut parameters and development of devices that eliminate air layer effects generated around the grinding wheel. This article will collaborate with the development of an experimentation methodology which allows evaluating, comparatively, the performance of the deflectors in the cutting region to minimize the air layer effect of the high speed of the grinding wheel. The air layers make the cutting fluid jet to dissipate in the machine. An optimized nozzle was used in order to compare the results with the conventional method (without baffles or deflectors) of cutting fluid application. The results showed the high eficciency of the deflectors or baffles in the finish results. Copyright © 2006 by ABCM.

Análise distribuição da carga hidráulica e vazão na unidade operacional de um sistema de irrigação localizada

The different combination possibilities of emission uniformity and field slope within the operational unities of localized irrigation systems favor the occurence of some configurations in the irrigation system, and consequently different hydraulic head distributions, discharge and system management. After the system has been implanted, it is necessary to verify pressure and discharge distribution in the operational unit. This work objective was to verify pressure and discharge uniformity on derivation line and lateral lines with micro sprinkle in data gotten from operational research. The results allow to check that despite analyzed declivity; the higher the emission uniformity calculated for the line of derivation in the project is, the higher its pressure uniformity is. Previously the results of discharge in the emitters of the operational unit showed a constant variation entering the point of higher discharge and lower discharge, even though differently from the three tested irrigation blades.

Simulação numérica do escoamento de jatos impingentes axissimétricos confinados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Implementação do método das características na modelagem de problemas de convecção natural em cavidades cilíndricas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Numerical solution of the FENE-CR model in complex flows

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

Dipolo e escoamento uniforme: escoamento em torno de um cilindro circular

The study of movements of ideals fluids is more simple that the viscous fluids because do not have the presence of tension of shear. The normal tensions are the one that must be considered in this analysis. The theory corresponding to these flows is the same used in other fields of the physics called Theory of Potentials Fields, which the vector identity is fundamental. Any flow into irrotational (null vorticity) physically possibly has a current function and a potential of velocity that satisfied the equation of Laplace. Reciprocally, any solution of equation of Laplace represents a current function or a potential of velocity of a flow into physically possible. Once the equation of Laplace is linear, the addiction of any numbers of solutions is also a solution. So, several potentials flows into can be constructed superposing configurations of elementary flows into. The purpose of the superposition of elementary flows into is a production of similar configurations to those of practical interest. The combination of mathematical elegancy with utility in the potential flow into attracted many for its study. Some of the most famous mathematician of history studied the theory and application of “hydrodynamic”, how was called the potential fluid into before 1900

Solução das equações de Navier-Stokes e da equação de transporte por um método de elementos finitos estabilizado pela técnica de separação baseada na característica

Pós-graduação em Engenharia Mecânica - FEIS

Experimental peritonitis in horses: peritoneal fluid composition

Dezesseis eqüinos adultos foram aleatoriamente divididos em quatro grupos de quatro animais que receberam inoculação intraperitoneal das seguintes suspenções: grupo I, 100×10(7) unidades formadoras de colônias (CFU) de E. coli diluídas em 500ml de solução salina a 0,9%; grupo II, 100×10(7) CFU de Bacteroides fragilis em 500ml de solução salina a 0,9%; grupo III, 100×10(7) CFU de E. coli combinados com 100×10(7) CFU de B. fragilis em 500ml de solução salina a 0,9%; grupo IV, 500ml de solução salina a 0,9%. Observou-se aumento significativo do número de leucócitos no líquido peritoneal quatro horas após as inoculações dos animais dos grupos I e II, e oito horas após as inoculações dos animais do grupo III. A contagem mais elevada foi de 516×10³ leucócitos/mm³. Aumentos significativos nas concentrações de fibrinogênio (1g/dl) e proteína total (9,1%) foram também observados. Eqüinos inoculados com culturas puras, tanto de E. coli quanto de B. fragilis, apresentaram peritonites mais brandas e autolimitantes, enquanto que eqüinos inoculados com associação das duas bactérias apresentaram alterações laboratoriais com maior intensidade e duração.

EVALUATION OF PERITONEAL-FLUID IN HORSES WITH EXPERIMENTAL ENDOTOXEMIA

Clinical parameters and biochemical and cellular changes in the plasma and peritoneal fluid were evaluated in horses after i.v. injection of a sub-lethal dose (50 ng/kg) of E. coli endotoxin. A significant decrease in the number of neutrophils and lymphocytes occurred in the blood 1h 15 min and 3 hours after injection of endotoxin; body temperature was increased significantly at the 3rd hour. No changes were detected in the total number of white blood cells in the peritoneal fluid. No significant differences in biochemical values were detected in either plasma or peritoneal fluid. Endotoxemia caused an alteration in blood cellularity, without effecting the peritoneal cellular population.

Efficacy of florfenicol and intravenous fluid therapy for treatment of experimental salmonellosis in newborn calves

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

Structural real time control using fluid magnetorheologic damper

In the last decades there was a great development in the study of control systems to attenuate the harmful effect of natural events in great structures, as buildings and bridges. Magnetorheological fluid (MR), that is an intelligent material, has been considered in many proposals of project for these controllers. This work presents the controller design using feedback of states through LMI (Linear Matrix Inequalities) approach. The experimental test were carried out in a structure with two degrees of freedom with a connected shock absorber MR. Experimental tests were realized in order to specify the features of this semi-active controller. In this case, there exist states that are not measurable, so the feedback of the states involves the project of an estimator. The coupling of the MR damper causes a variation in dynamics properties, so an identification methods, based on experimental input/output signal was used to compare with the numerical application. The identification method of Prediction Error Methods - (PEM) was used to find the physical characteristics of the system through realization in modal space of states. This proposal allows the project of a semi-active control, where the main characteristic is the possibility of the variation of the damping coefficient.

Fuzzy control embedded in microcontroller and applied to an experimental apparatus using magnetorheological fluid damper

This work focuses on applying fuzzy control embedded in microcontrollers in an experimental apparatus using magnetorheological fluid damper. The non-linear behavior of the magnetorheological dampers associated with the parametric variations on vehicle suspension models corroborate the use of the fuzzy controllers. The fundamental formulation of this controller is discussed and its performance is shown through numeric simulations. An experimental apparatus representing a two degree of freedom system containing a magnetorheological damper is used to identify the main parameters and to evaluate the performance of the closed-loop system with the embedded low-cost microcontroller-based fuzzy controller. © 2013 Brazilian Society for Automatics - SBA.

EXPERIMENTAL STUDY ABOUT CHECK VALVE IN NEUROLOGICAL APPLICATION

In the present work is proposed the experimental study of hydrodynamic behaviour of membrane neurological valve, applied in treatment of hydrocephalus, a pathophisiology that affects both adults and children, caused due to the excess of cerebrospinal fluid in brain ventricles.