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.

Evidence for a respiratory component, similar to mammalian respiratory sinus arrhythmia, in the heart rate variability signal from the rattlesnake, Crotalus durissus terrificus

Autonomic control of heart rate variability and the central location of vagal preganglionic neurones (VPN) were examined in the rattlesnake ( Crotalus durissus terrificus), in order to determine whether respiratory sinus arrhythmia (RSA) occurred in a similar manner to that described for mammals. Resting ECG signals were recorded in undisturbed snakes using miniature datalogging devices, and the presence of oscillations in heart rate (f(H)) was assessed by power spectral analysis (PSA). This mathematical technique provides a graphical output that enables the estimation of cardiac autonomic control by measuring periodic changes in the heart beat interval. At fH above 19 min(-1) spectra were mainly characterised by low frequency components, reflecting mainly adrenergic tonus on the heart. By contrast, at f(H) below 19 min(-1) spectra typically contained high frequency components, demonstrated to be cholinergic in origin. Snakes with a f(H) > 19 min(-1) may therefore have insufficient cholinergic tonus and/or too high an adrenergic tonus acting upon the heart for respiratory sinus arrhythmia ( RSA) to develop. A parallel study monitored f(Hd) simultaneously with the intraperitoneal pressures associated with lung inflation. Snakes with a fH < 19 min(-1) exhibited a high frequency (HF) peak in the power spectrum, which correlated with ventilation rate (f(V)). Adrenergic blockade by propranolol infusion increased the variability of the ventilation cycle, and the oscillatory component of the f(H) spectrum broadened accordingly. Infusion of atropine to effect cholinergic blockade abolished this HF component, confirming a role for vagal control of the heart in matching f(H) and f(V) in the rattlesnake. A neuroanatomical study of the brainstem revealed two locations for vagal preganglionic neurones (VPN). This is consistent with the suggestion that generation of ventilatory components in the heart rate variability (HRV) signal are dependent on spatially distinct loci for cardiac VPN. Therefore, this study has demonstrated the presence of RSA in the HRV signal and a dual location for VPN in the rattlesnake. We suggest there to be a causal relationship between these two observations.

Some comments on the F ring-Prometheus-Pandora environment

The system formed by the F ring and two close satellites, Prometheus and Pandora, has been analysed since the time that Voyager visited the planet Saturn. During the ring plane crossing in 1995 the satellites were found in different positions as predicted by the Voyager data. Besides the mutual effects of Prometheus and Pandora, they are also disturbed by a massive F ring. Showalter et al. [Icarus 100 (1992) 394] proposed that, the core of the ring has a mass which corresponds to a moonlet varying in size from 15 to 70 kin in radius which can prevent the ring from spreading due to dissipative forces, such as Poynting-Robertson drag and collisions. We have divided this work into two parts. Firstly we analysed the secular interactions between Prometheus-Pandora and a massive F ring using the secular theory. Our results show the variation in eccentricity and inclination of the satellites and the F ring taking into account a massive ring corresponding to a moonlet of different sizes. There is also a population of dust particles in the ring in the company of moonlets at different sizes [Icarus 109 (1997) 304]. We also analysed the behaviour of these particles under the effects of the Poynting-Robertson drag and radiation pressure. Our results show that the time scale proposed for a dust particle to leave the ring is much shorter than predicted before even in the presence of a coorbital moonlet. This result does not agree with the confinement model proposed by Dermott et al. [Nature 284 (1980) 309]. In 2004, Cassini mission will perform repeated observations of the whole system, including observations of the satellites and the F ring environment. These data will help us to better understand this system. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

Wetland projects developed in Brazil

The first studies with constructed wetlands undertaken in Brazil were the result of observations made from the Amazon flood plains. The first attempt to use this capacity to change the quality of the water, in the sense of purification performed in Brazil using constructed wetland systems, was made by Salati et al. After that, new technologies were developed in a focused attempt to increase the efficiency of the system and reduce investments. Over these 18 years, persuading the Brazilian scientific community as well as the environmental control agencies to give due attention to this kind of research has required endless efforts. Only in recent years have major institutions responsible for sewage treatment and potable water supply been concerned with this type of technology for solving real problems. These institutions are as follows: SABESP (Basic Sanitation Company of Sao Paulo State), SANEPAR (Sanitation Company of Parana State) and CESP (Electric Company of Sao Paulo State). One of the private institutions that has systematically worked in the design and projects of constructed wetlands is the Institute of Applied Ecology. This institution has enhanced and developed a water depuration system based on the purifying capacity of the soil. The wetlands with filtering soils are systems formed by overlapping layers of crushed stone, gravel and soil planted with rice. This technology has been used in sewage treatment and also in water supply systems.

Aplicação da metodologia de superfície de resposta na remediação de um solo arenoso contaminado artificialmente com cobre

Soil flushing is an alternative remediation technology for soils contaminated with heavy metals, which the main contaminant removing process consists in percolating an extraction solution. This work aimed to use the response surface methodology to point out combinations among the parameters of the extraction solution (Na2EDTA concentration, volume e pH) in order to reduce the concentration of copper in a sandy soil to risk levels lower than the intervention levels for exposure scenarios adopted by the Environmental Company of Sao Paulo State. Thus, a series of tests in leaching columns were carried out using a Fluvisol artificially contaminated (1257,3 mg kg-1). The tests were conducted in triplicate and setup a central composite rotatable design with 15 different parameters combinations of the extraction solution and one replicate in the center point. Using 5% significance level, the adjusted model (R2 = 0,98) indicated combinations of Na2EDTA concentration, pH and volume of the extraction solution which allow reduction of copper concentration below levels reported by environmental agency of Sao Paulo State for industrial, residential, agricultural or maximum exposure scenarios.

Práxis intervencionista na escola: experiências de ressignificação, deslocamento e insurgência

Pós-graduação em Artes - IA

O financiamento da firma e os arranjos produtivos locais: uma abordagem do APL Aeroespacial de São José dos Campos-SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A indústria de defesa brasileira: o setor de carros de combate e a Engesa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A Companhia de Jesus e a formação da cultura sexual brasileira: um estudo histórico e documental a partir dos escritos do padre Manuel da Nóbrega

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação das propriedades mecânicas e da microestrutura de aços dissimilares ABNT 8620 e ABNT 6655 LN 28 soldados com arco pulsado com diferentes temperaturas de pré-aquecimento e tipos de tecimento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos biológicos de Quesada gigas (Olivier, 1790) (Hemiptera: Cicadidae) em cafeeiro

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Aplicação da metodologia de superfície de resposta na otimização da remediação de um solo arenoso contaminado com cobre

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da presença de vapores no solo em antiga área industrial contaminada por hidrocarbonetos: concentrações medidas e simuladas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Monitoramento da vibração causada por detonações em mina subterrânea de carvão (Mina Trevo - Siderópolis, SC) como subsídio ao estabelecimento de uma política de relacionamento com a comunidade do entorno da mineração

Pós-graduação em Geociências e Meio Ambiente - IGCE

Um estudo sobre os benefícios e dificuldades da gestão ambiental com base na Norma ISO 14001 em empresas industriais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)