Alfvén wave heating and runaway discharges in the TCABR tokamak

Recent results of experiments on Alfvén wave heating and runaway discharges carried out in the TCABR tokamak are presented. A new antenna type has been installed to allow wave excitation with higher RF currents and lower dynamic polarization of the antenna straps than for the one previously used. In spite of edge plasma heating, which causes influx of impurities, we have obtained a clear confirmation of wave deposition inside the plasma from a localized increase of the electron temperature measured with the ECE radiometer. Detailed profiles of the plasma density and Ha emission were obtained in runaway disharges with currents around 100 kA. These profiles confirm our model of a low-temperature plasma maintained in equilibrium by the relativistic electron beam. Analysis of the Ha and density spikes indicate that recombination plays a substantial role in the particle and energy balance

Nutritional Security/insecurity In Urban And Rural Families Of Amazonas State: Validation Of Methodology And Of Information Collecting Instrument [segurança/insegurança Alimentar Em Famílias Urbanas E Rurais No Estado Do Amazonas: I. Validação De Metodologia E De Instrumento De Coleta De Informação]

The present study validates the methodology and the information collecting instrument for analysis of nutritional security/insecurity on the urban and rural family level, proposed by the USDA (United States Department of Agriculture). An intentional sample of domiciles was selected to represent different social strata, 194 families were enrolled in urban Manaus, of which 174 had children, in the following neighborhoods: Jesus me Deu, Nova Israel, Cidade Nova, Coroado and Conj. Petro. In the rural area between the municipalities of Iranduba and Manacapuru, 209 riparian families were interviewed, and of these 131 had children. The final validation of the questionnaire (global internal consistency) was made by comparing, the levels of nutritional security/insecurity, with the defined social strata and food consumption indicators. The results demonstrated that the groups of highest nutritional insecurity were the very poor. The instrument presented high validation and internal consistency.372247252Albert, P.L., Sanjur, D., The adaptation and validation of the food security scale in a community of Caracas, Venezuela (2000) Arch. Latinoam. Nutr, 50 (4), pp. 334-340Cohen, B., (2005) Community Food Security Assessment Toolkit. ERS E-FAN No. 02-013. 2002. p. 166, , http://www.ers.usda.gov/publications/efan02013/). Acesso: 23/04/2005Frongillo, E.A., Validation of measures of food insecurity and hunger (1999) J Nutr, 129 (SUPPL. 2), pp. 506-509(2001) Projeto Fome Zero: Uma política de segurança alimentar para o Brasil, , Instituto Cidadania, São Paulo: Instituto da Cidadania. 118ppLeão, M., (2005) Segurança Alimentar e Risco de Sobrepeso e Obesidade em famílias de crianças menores de 6 anos, , Dissertação Mestrado. Universidade de Brasília, Brasília, DF. 121ppPanigassi, G., (2005) Inquérito populacional sobre a percepção da segurança alimentar intrafamiliar no município de Campinas, SP, , Tese de Doutorado, Universidade Estadual de Campinas, Campinas, São Paulo. 188ppPerez-Escamilla, R., Randolph, S., Hathie, I., Gaye, I., Adaptation and validation of the USDA food security scale in rural Senegal (2004) FASEB J, 18, pp. A106Perez-Escamilla, R., Segall-Corrêa, A.M., Maranha, L.K., Sampaio, M.F.A., Marin-León, L., Panigassi, G., An adapted version of the U.S. Department of Agriculture Food Insecurity Module is a valid tool for assessing household food insecurity in Campinas (2004) Brasil. J. Nutr, 134, pp. 1923-1928Radimer, K.L., Measurement of household food security in the USA and other industrialised countries (2002) Public Health Nutr, , 5(6A):859-864Segal-Corrêa, A.M., Escamilla, R.P., Maranha, L.K., Sampaio, M.F.A., Relatório Técnico. Versão preliminar Acompanhamento e avaliação da Segurança alimentar de famílias brasieleiras:Validação de Metodologia e de instrumento de coleta de informação (2004) Urbano/rural, , UNICAMP. Campinas. 33ppStuddert, L.J., Frongillo, E.A., Valois, P., Household food insecurity was prevalent in Java during Indonesia's economic crisis (2001) J Nutr, 131 (10), pp. 2685-2691(2003) Food security in the United States: History of the food security measurement, , http://www. ers.usda.gov/briefing/foodsecurity/history). Acesso: 22/08/2003, United Stater Department of Agriculture, projec

Heavy metals extractability in a soil amended with sewage sludge Extractabilidade de metais pesados em um solo tratado com lodo de esgoto

Few investigations have been carried out about the comparison of desorption rate and amount of heavy metals extracted successively by organic acid mixtures mimicking the rhizosphere and routine extractants in sewage sludge-amended soils. Extractions of Zn, Cd, Ni, Cr, and Cu were performed in samples of a sewage sludge-amended soil using seven extractants: four organic acid mixtures and three routine extractants (DTPA, Mehlich-I, and ammonium acetate). Results from single pass extractions, in which the extractable metal contents were determined by simply extracting the soil a single time, as well as from 15 successive extractions, in which the solid residues of the first extraction was successively extracted 14 additional times, of heavy metals were analyzed. The extractability of heavy metals in a single pass extraction was, in general, as follows: Mehlich-I > DTPA > organic acids > NH4OAc. The highest rates of extraction followed the general order: DTPA > Mehlich-I > organic acids > NH4OAc. While Mehlich-I presented the highest extractability of heavy metals among studied extractants, DTPA showed a high extractability of Zn, Cd, Ni, and Cu in a single extraction as well as the highest rates of extraction among the studied extractants. The transfer of heavy metals from soil to organic acid solutions is slower than to DTPA and Mehlich-I extractants.<br>Poucos trabalhos têm sido realizados sobre a comparação da taxa de dessorção e da quantidade de metais extraídos sucessivamente por misturas de ácidos orgânicos que imitam a composição da rizosfera e por extratores usados na rotina em amostras de solo tratado com lodo de esgoto. Extrações de Zn, Cd, Ni, Cr e Cu foram realizadas em amostras de um solo de carga variável tratado com lodo de esgoto usando-se sete extratores: quatro misturas com ácidos orgânicos e três extratores usados na rotina (DTPA, Mehlich-I e acetato de amônio). Os resultados para uma única extração, em que o conteúdo de metais extraíveis foi determinado simplesmente extraindo-os do solo uma única vez, bem como após 15 extrações sucessivas, em que o resíduo sólido da primeira extração foi extraído sucessivamente por mais 14 vezes, foram analisados. A extractabilidade dos metais em uma extração simples foi, em geral, como segue: Mehlich-I > DTPA > ácidos orgânicos > NH4OAc. As mais elevadas taxas de extração seguiram a ordem: DTPA > Mehlich-I > ácidos orgânicos > NH4OAc. A maior extração de metais foi obtida com Mehlich-I, enquanto, o DTPA também extraiu alta quantidade de Zn, Cd, Ni e Cu em uma extração simples, bem como obteve as mais altas taxas de extração entre os extratores estudados. A transferência de metais do solo para as soluções de ácidos orgânicos foi mais lenta que para os extratores DTPA e Mehlich-I

Overview Of Recent Results Of Tcabr

An overview of recent results obtained in TCABR is presented. Experiments on Alfvén wave heating have been carried out in both low and high density regimes. Controlling the density rise usually observed in Alfvén heating experiments, it was possible to get a clear confirmation of electron temperature increase in low-density discharges. In the high density regime, the Alfvén wave absorption occurs at mode numbers quite different from those for low density. Detailed experiments have been carried out on the transition between low and high-density confinement regimes, triggered by electrostatic polarization at the plasma edge. The results indicate that the flatness of the density profile and the decrease of edge recycling depend strongly on the level of MHD activity during transition. A preliminary analysis of the electromagnetic emission associated with the relaxation instability in the new regime of runaway discharges discovered in TCABR shows that the observations are coherent with theoretical models. The heat transport in the presence of large magnetic islands has been investigated, in the collisional regime, and found to be properly described by the Fitzpatrick model. Finally, two diagnostic techniques have been further improved, the determination of the position of the local Alfvén resonance by microwave reflectometry and the determination of the temperature and density at the plasma edge by the method based upon the uniqueness of the particle confinement time, determined from the hydrogen Balmer series emission. © 2006 American Institute of Physics.87535035