Morfoanatomia do sistema subterrâneo de Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson (Asteraceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morfoanatomia dos órgãos vegetativos de Smilax polyantha Griseb. (Smilacaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ciclo reprodutivo do caranguejo violinista Uca rapax (Smith) (Crustacea, Brachyura, Ocypodidae) habitante de um estuário degradado em Paraty, Rio de Janeiro, Brasil

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

Uso de nomes populares para as espécies de Araceae e Dioscoreaceae no Brasil

A origem dos nomes vulgares das espécies muitas vezes é obscura ou mesmo impossível de ser identificada. Face à semelhança que apresentam alguns tipos de sistema subterrâneo de Dioscorea com aqueles das espécies de Colocasia, observa-se em muitos trabalhos publicados na literatura brasileira uma certa confusão na terminologia usada para definir estruturas principalmente em algumas espécies de inhame e cará. A padronização no Brasil da nomenclatura das estruturas subterrâneas destas hortaliças, à luz dos Códigos Internacionais de Nomenclatura Botânica e das Plantas Cultivadas, permitirá melhor entendimento para pesquisadores, extensionistas, sociedades civis organizadas, importadores, produtores, comerciantes e consumidores, na identificação das espécies cultivadas de cada família botânica e na interpretação das informações.

O jardim de fungo atua como um molde para a construção das câmaras em formigas cortadeiras?

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Field methods for the study of ants in sugarcane plantations in Southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mineração subterrânea de carvão X comunidade no seu entorno: um exemplo de Santa Catarina

Historicamente a convivência entre a mineração e a população sempre foi problemática, com prejuízos enormes para esta última, que, por problemas da falta de moradia, tem de conviver com a degradação do meio ambiente ao seu redor, como a poluição através da poeira, ruído e vibração. Esse trabalho, com dados coletados na mina subterrânea de carvão Trevo, na região carbonífera de Santa Catarina, coloca em evidência a necessidade da integração Empresa x Comunidade, no sentido da melhoria das técnicas de mineração e do meio ambiente, visando a uma convivência pacífica e tendo como um dos seus principais resultados alertar e despertar a consciência da Empresa ante aos reclamos da comunidade, demonstrando-se com dados, o perigo decorrente do planejamento de uma lavra sem levar em conta as habitações em superfície.

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.

Nest architecture of Atta laevigata (F. Smith, 1858) (Hymenoptera : Formicidae)

The internal structure of three nests of Atta laevigata was studied in Botucatu city, São Paulo State, Brazil. Two nests were excavated through the opening of trenches and one was cement-moulded to enable a better view of the internal structures. The three nests presented a similar structure, with the depths and number of chambers varying as a function of the loose soil area of the nests. The number of chambers ranged from 1149 to 7864, reaching as deep as 7 m underground. Chamber volume ranged from 0.03 to 511. The foraging tunnels extended as far as 70m from the loose soil region. The nests of this species are the deepest within the genus Atta and have the highest number of chambers.

A method for evaluating Ra-228 in environmental matrices and its use at Pocos de Caldas plateau, Brazil

This work describes a methodology developed for performing the extraction, detection and quantification of Ra-228 in waters, suspended solids and sediments. The technique proved to be useful for analyzing samples from the hydrological environment of Morro do Ferro, Pocos de Caldas plateau, Brazil. The 228Ra activity in underground waters of 5 boreholes drilled in the area varied from 0.02 up to 14.5 Bq/l, whereas for the surficial waters the variation was from 0.04 to 0.51 Bq/l; for the suspended solids, the values ranged from 1.5 up to 419 Bq/g, whereas it was possible to find a value of 2.04 Bq/g for the sediments. These results show the applicability of the method for characterizing different matrices of environmental interest. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

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].

Ocorrência de Scaptocoris castanea, perty 1830 em pastagens cultivadas no Brasil

The brown bug (Scaptocoris castanea, Perty 1830) is an insect of underground habits, which continuously suctions the juice through the roots leads the plants to emaciate, dry and die. It has not yet been described as pest in cultivated pastures in Brazil. Its occurrence has been observed in cultivated pastures of Cynodon dactylon cv. Coast cross and Brachiaria decumbens cv Brasilik and IPEAN in red-yellow podzolic soil originally covered by savannah vegetation, in Botucatu County, state of São Paulo.

Stochastic field processes in the mathematical modelling of damped transmission line vibrations

Wind-excited vibrations in the frequency range of 10 to 50 Hz due to vortex shedding often cause fatigue failures in the cables of overhead transmission lines. Damping devices, such as the Stockbridge dampers, have been in use for a long time for supressing these vibrations. The dampers are conveniently modelled by means of their driving point impedance, measured in the lab over the frequency range under consideration. The cables can be modelled as strings with additional small bending stiffness. The main problem in modelling the vibrations does however lay in the aerodynamic forces, which usually are approximated by the forces acting on a rigid cylinder in planar flow. In the present paper, the wind forces are represented by stochastic processes with arbitrary crosscorrelation in space; the case of a Kármán vortex street on a rigid cylinder in planar flow is contained as a limit case in this approach. The authors believe that this new view of the problem may yield useful results, particularly also concerning the reliability of the lines and the probability of fatigue damages. © 1987.

The behavior of dissolved uranium in groundwaters of the Morro do Ferro thorium deposit, Brazil

Groundwater samples were collected for several months in boreholes drilled at Morro do Ferro, a thorium and rare earth deposit located on the Poços de Caldas Plateau, Minas Gerais State, Brazil. An aquifer system has developed in the weathered mantle due to in situ intense alteration. The weathered zone includes a thick argillaceous laterite greater than 100 m thick. The U content and 324U/238U activity ratio were measured in the groundwater samples and in spoil samples of a borehole drilled in the ore body. Some possible mechanisms related to the mobilization of uranium are considered such as complexation with humic substances and adsorption by clays. © 1989.

Obtencao e interpretacao de dados de Reflexao Sismica Superficial (Rasa) - exemplos e aplicacoes

Successful application of shallow seismic reflection method is related directly to the ability of the ground to transmit high-frequency seismic energy from a seismic source. The dominant frequencies of reflection data are in the range of 50 to 100 Hz and depend on the surface materials and water table. A spread of geophones send the siemsic signal to be recorded on a 12, 24 or 48 channel portable seismograph, using a single high-frequency geophone per channel. Although it is possible to find seismographs with display and processing unities, it is also possible to transfer digitalized data to a personal computer to be processed and interpreted by using specific programs. Some results of two recent field studies to specify the underground structure in the tidal flats area of Baie St. Paul (Quebec-Canada) and in glacial terrains, in the Waterloo (Ontario-Canada) region. -from English summary