On a nonlinear and chaotic non-ideal vibrating system with shape memory alloy (SMA)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Informações biológicas e estimativa do tamanho ideal da colmeia para a abelha tiúba do Maranhão (Melipona compressipes fasciculata Smith - Hymenoptera, Apidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A questão do meio na pedologia e suas implicações pedagógicas

Ce texte est une lecture de la conférence de Vygotsky sur la question de l'influence de la culture et de l'environnement sur la pédologie et cherche les implications pédagogiques des ces idées sur l'éducation des enfants et, en particulier, les petits enfants. Initialement, met en évidence la méthode de l'auteur que enseigne à ses auditeurs et lecteurs à penser dialectiquement, un défi que doit être confrontés par les lecteurs - habitués à penser avec la logique formelle - pour essayer de comprendre les études de Vygotsky. Deux éléments apportés par Vygotsky à la conférence sont prise pour réfléchir sur son importance pour le développement de l'enfant: la question de la langue orale et de son importance pour l'influence de la culture et de l'environnement sur le développement humain dans l'enfance et la spécificité du développement culturel dans l'enfance que dit que ce que nous pouvons parvenir à la fin ou à la suite du processus de développement est présente dans la culture depuis le début et touche et guide ce développement de l'enfant. Dans les deux cas, la discussion au sein de cette conférence de Vygotsky déclenche une révolution dans la pensée et l'action des enseignants.

Segmentação anatomocirúrgica arterial dos pulmões de ovinos da raça ideal (Ovis aires - L.1758)

Foram estabelecidos segmentos anatomocirúrgicos em pulmões de ovinos da raça Ideal (dezessete segmentos no pulmão direito e doze no esquerdo), mediante dissecação de peças coradas com látex colorido e fixadas em formol. Na maioria dos casos, a artéria pulmonar direita emite, a partir de um tronco, o ramo ascendente e descendente para as partes cranial e caudal do lobo cranial respectivamente; o ramo do lobo médio; o ramo do lobo caudal e o ramo do lobo acessório. Invariavelmente, a artéria pulmonar esquerda emite o ramo do lobo cranial e o ramo do lobo caudal.

Nonlinear Dynamics and Control of an Ideal/Nonideal Load Transportation System With Periodic Coefficients

In this paper, a loads transportation system in platforms or suspended by cables is considered. It is a monorail device and is modeled as an inverted pendulum built on a car driven by a dc motor the governing equations of motion were derived via Lagrange's equations. In the mathematical model we consider the interaction between the dc motor and the dynamical system, that is, we have a so called nonideal periodic problem. The problem is analyzed, qualitatively, through the comparison of the stability diagrams, numerically obtained, for several motor torque constants. Furthermore, we also analyze the problem quantitatively using the Floquet multipliers technique. Finally, we devise a control for the studied nonideal problem. The method that was used for analysis and control of this nonideal periodic system is based on the Chebyshev polynomial exponsion, the Picard iterative method, and the Lyapunov-Floquet transformation (L-F transformation). We call it Sinha's theory.

The Brazilian pediatric myelodysplastic cooperative group strategies: are they relevant to improve educational approach and correct diagnosis?

Brazil is a wide country with huge contrasts. Its peculiarities can highlight environmental factors that could influence the frequencies of different cancers. The standard treatment and results achieved from several different areas of the country may not be found in others. The establishment of a national cooperative group has the potential to improve outcomes. The The Brazilian Cooperative Group on Pediatric Patients with Myelodysplastic Syndrome (BCG-MDS-PED) was first organized in January 1997 as a working group of hematologists, pediatric oncologists, pediatric-hematologists, molecular biologists and other professionals in order to study pediatric (age < 18 years) MDS. Six distinct subcommittees constituted with members from several universities: cytology, histopathology, clinical, cytogenetics, molecular biology and epidemiology. The goals of the BCG-MDS-PED were: (i) to offer support for diagnosis and orientation for treatment; (ii) educational Support for the colleagues all over the country and (iii) research on pathogenesis and new approaches for pediatric MDS patients. There are socio-economical differences among the five regions of the country. The BCG-MDS-PED believes that it is absolutely necessary to Study the clinical, cellular, molecular and epidemiological aspects of MDS, taking in account these peculiar differences among populations and regions. Since 1997, 114 pediatric cases were referred to the BCG-MDS-PED from 21 centres. Seven Brazilian states have sent cases to the group, 31 patients were referred from universities, 73 patients from pediatric oncology units (foundations) and 10 patients came from private clinics. Some of these patients have been followed up and/or treated by the physician who referred them to the BCG-MDS-PED for confirmation of the initial diagnosis. The majority of these physicians have required orientation on diagnostic and treatment issues, as well as to complete cytogenetic and molecular studies. From these 114 patients, 64 patients were confirmed as MDS. We believe that, the more numerous the MDS-studied cases, the more experienced will be the referee group on clinical and laboratory features on childhood MDS in Brazil. (C) 2002 Published by Elsevier B.V. Ltd.

On non-ideal simple portal frame structural model: Experimental results under a non-ideal excitation

We present measurements of the non-linear oscillations of a portal frame foundation for a non-ideal motor. We consider a three-time redundant structure with two columns, clamped in their bases and a horizontal beam. An electrical unbalanced motor is mounted at mid span of the beam. Two non-linear phenomena are studied: a) mode saturation and energy transfer between modes; b) interaction between high amplitude motions of the structure and the rotation regime of a real limited power motor. The dynamic characteristics of the structure were chosen to have one-to-two internal resonance between the anti-symmetrical mode (sway motions) and the first symmetrical mode natural frequencies. As the excitation frequency reaches near resonance conditions with the 2nd natural frequency, the amplitude of this mode grows up to a certain level and then it saturates. The surplus energy pumped into the system is transferred to the sway mode, which experiences a sudden increase in its amplitude. Energy is transformed from low amplitude high frequency motion into high amplitude low frequency motion. Such a transformation is potentially dangerous.We consider the fact that real motors, such as the one used in this study, have limited power output. In this case, this energy source is said to be non-ideal, in contrast to the ideal source whose amplitude and frequency are independent of the motion of the structure. Our experimental research detected the Sommerfeld Effect: as the motor accelerates to reach near resonant conditions, a considerable part of its output energy is consumed to generate large amplitude motions of the structure and not to increase its own angular speed. For certain parameters of the system, the motor can get stuck at resonance not having enough power to reach higher rotation regimes. If some more power is available, jump phenomena may occur from near resonance to considerably higher motor speed regimes, no stable motions being possible between these two.

Psychophysical power functions for estimates of area: Effects of age and educational levels

The purpose of the present study was to verify the memory exponents of power function for area in observers of different age and educational levels (elementary school, high school or undergraduate school), using the psychophysics method of magnitude estimation. For the age level I (17 to 30 years old) there was no difference among educational levels, although for the age level II (45 to 60 years old) the differences were significant. Tn the age level II, there was a tendency for greater variability of the responses for lower educational levels. The data obtained for the age level I did not show the same results, although a significant difference among the three educational levels was observed. We call conclude that the mnemonic processes present different results when we observe the answers from observers with different ages. This result leads us to suppose that the motivational factor related to the stimulus used can interact with the mnemonic processes.

On a control of a non-ideal mono-rail system with periodics coefficients

In this work, the problem in the loads transport (in platforms or suspended by cables) it is considered. The system in subject is composed for mono-rail system and was modeled through the system: inverted pendulum, car and motor and the movement equations were obtained through the Lagrange equations. In the model, was considered the interaction among of the motor and system dynamics for several potencies motor, that is, the case studied is denominated a non-ideal periodic problem. The non-ideal periodic problem dynamics was analyzed, qualitatively, through the comparison of the stability diagrams, numerically obtained, for several motor torque constants. Furthermore, one was made it analyzes quantitative of the problem through the analysis of the Floquet multipliers. Finally, the non-ideal problem was controlled. The method that was used for analysis and control of non-ideal periodic systems is based on the Chebyshev polynomial expansion, in the Picard iterative method and in the Lyapunov-Floquet transformation (L-F trans formation). This method was presented recently in [3-9].

An overview on non-ideal vibrations

We analyze the dynamical coupling between energy sources and structural response that must not be ignored in real engineering problems, since real motors have limited output power.

New concepts of the power received by ideal energy storage elements: the instantaneous complex power approach

This paper presents some definitions and concepts of the Instantaneous Complex Power Theory [1] which is a new approach for the Akagi's Instantaneous Reactive Power Theory [2].The powers received by an ideal inductor are interpreted and the knowledge of the actual nature of these powers may lead to changes of the conventional electrical power concepts.

Use of ideal protein concept for precision formulation of amino acid levels in fish-meal-free diets for juvenile Nile tilapia (Oreochromis niloticus L.)

This study was undertaken in a closed system with Nile tilapia (Oreochromis niloticus) to examine the effects of total replacement of fish meal (FM) by soybean meal. Nile tilapia fingerlings with an average weight of 5.34+/-0.08 g were hand-fed one of the five isoenergetic (approximate to13.5 MJ digestible energy kg(-1)) and isoproteic (approximate to31% of digestible protein) experimental diets to satiation, six times a day during 85 days in eight replicate fibreglass tanks (six fish per tank). The control diet containing FM was substituted by soybean meal, with and without essential amino acids (lysine, methionine and threonine) or dicalcium phosphate supplementation. The supplemental amino acids were added at levels to simulate the reference amino acid profile of Nile tilapia carcass protein, based on the ideal protein concept. The results showed that soybean meal diet supplemented only with dicalcium phosphate was inferior to the control diet with FM and soybean meal diets supplemented with dicalcium phosphate and essential amino acids. Multiple essential amino acids and dicalcium phosphate incorporation in soybean meal diets was associated with performance, whole-body composition and carcass yield equal to that of the fish fed with the control diet containing FM. These data suggest that a diet with all plant protein source, supplemented with essential amino acids, based on tissue amino acid profile, can totally replace FM in a diet for Nile tilapia, without adverse effects on the growth performance, carcass yield and composition.