7 resultados para APON
Resumo:
Com o fim da Guerra Fria e os acontecimentos que marcaram o “onze de setembro”, novas ameaças surgiram, impactando negativamente a percepção de segurança coletiva, e impondo profundas modificações nas estruturas e no modo de atuação do Poder Militar de diversas nações. A marginalidade social, o narcotráfico, o crime organizado, a degradação do meio ambiente e outras tantas ameaças, fizeram com que algumas nações se vissem motivadas a empregar suas Forças Armadas, prioritariamente, no combate a estas mazelas, ou seja, nas operações de não-guerra. Este fenômeno vem causando uma ebulição nas ciências militares, com reflexo no campo social, político e econômico, provocando um processo conhecido como “Transformação da Defesa”, que só é viável com a ruptura de alguns modelos tradicionais de administração e com a introdução de uma nova cultura organizacional que promova um ambi-ente adequado ao processo de inovações no setor de Defesa. Para fazer gestão deste processo, deve haver um sistema de inovação setorial de Defesa, já que o atual modelo, conforme apon-tou a investigação, é fragmentado e desarticulado, que produz, fundamentalmente, inovações incrementais e, raramente as de ruptura. Trata-se de um sistema virtual, que não existe for-malmente como tal, mas que possui toda a infraestrutura necessária para funcionar como um sistema formal e gerenciável. A pesquisa, de caráter epistemológico estruturalista, teve por objetivo desenvolver um modelo conceitual para gestão do sistema de inovação do setor de Defesa (segmento de não-guerra), com base em uma estrutura subjacente desvelada, que, de forma oculta, dá suporte ao sistema atual. O desvelamento desta estrutura permitiu concluir que, no campo estudado, os agentes do sistema de inovação, agindo de acordo com seus inte-resses, mobilizam, de forma consciente ou inconsciente, os fatores valorativos da inovação presentes na cultura organizacional em que estão imersos, os quais, juntamente com a influên-cia dos fatores de suporte (o Capital), são fundamentais para a formação de alianças e, em consequência, para o processo de inovação no segmento de não-guerra do setor de Defesa. Como era esperado, o desvelamento da estrutura subjacente propiciou a realização de um di-agnóstico preciso do sistema estudado, permitindo ao pesquisador o lançamento de um olhar crítico sobre o mesmo, o que contribui para a proposição de uma intervenção segura no modelo vigente. O modelo proposto buscou incentivar, também, a criação, o avanço e a difusão das inovações não-tecnológicas, contrapondo-se ao atual, que privilegia fundamentalmente a abordagem tecnológica. Adicionalmente, foram sugeridas algumas medidas, no sentido de incrementar as interações entre os principais agentes do sistema.
Resumo:
Detailed analyses of persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs), hexachlorocyclohexane (HCH) isomers (HCHs), dichlorodiphenyltrichloro ethane (DDT) and its metabolites (DDTs) and congeners of polychlorinated biphenyls (PCBs) in soil and surface water from the northeastern São Paulo, Brazil allowed the evaluation of the contamination status, distribution and possible pollution sources. The pesticides and PCBs demonstrated markedly different distributions, reflecting different agricultural, domestic and industrial usage in each region studied. The ranges of HCH, DDT, and PCBs concentrations in the soil samples were 0.05-0.92, 0.12-11.01, 0.02-0.25 ng g(-1) dry wt, respectively, and in the surface water samples were 0.02-0.6, 0.02-0.58 and 0.02-0.5 ng l(-1), respectively. Overall elevated levels of DDT and PCB were recorded in region 2, a site very close to melting, automotive batteries industries, and agricultural practice regions. High ratios of metabolites of DDT to DDT isomers revealed the recent use of DDT in this environment. The sources of contamination are closely related to human activities, such as domestic and industrial discharge, street runoff, agricultural pesticides and soil erosion, due to deforestation as well as atmospheric transport. (c) 2006 Elsevier Ltd. All rights reserved.
Resumo:
An analytical procedure using supercritical fluid extraction (SFE) and capillary gas chromatography with electron-capture detection was developed to determine simultaneously residues of different pesticides (organochlorine, organophosphorus, organonitrogen and pyrethroid) in honey samples. Fortification experiments were conducted to test conventional extraction (liquid-liquid) and optimize the extraction procedure in SFE by varying the CO2-modifier, temperature, extraction time and pressure. Best efficiency was achieved at 400 bar using acetonitrile as modifier at 90 degreesC. For the clean-up step, Florisil cartridges were used for both methods LLE and SFE. Recoveries for majority of pesticides from fortified samples of honey at fortification level of 0.01-0.10 mg/kg ranged 75-94% from both methods. Limits of detection found were less than 0.01 mg/kg for ECD and confirmation of pesticide identity was performed by gas chromatography-mass spectrometry in selected-ion monitoring mode. The multiresidue methods in real honey samples were applied and the results of developed methods were compared. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
The applicability of supercritical fluid extraction (SFE) in pesticide multiresidue analysis (organohalogen, organonitrogen, organophosphorus, and pyrethroid) in soil samples was investigated. Fortification experiments were conducted to test the conventional extraction (solid-liquid) and to optimize the extraction procedure in SFE by varying the CO2 Modifier, temperature, extraction time, and pressure. The best efficiency was achieved at 400 bar using methanol as modifier at 60 degreesC. For the SFE method, C-18 cartridges were used for the cleanup. The analytical screening was performed by gas chromatography equipped with electron-capture detection (ECD). Recoveries for the majority of pesticides from spiked samples of soil at different residence times were 1, 20, and 40 days at the fortification level of 0.04-0.10 mg/kg ranging from 70 to 97% for both methods. The detection limits found were <0.01 mg/kg for ECD, and the confirmation of pesticide identity was performed by gas chromatography-mass spectrometry in a selected-ion monitoring mode. Multiresidue methods were applied in real soil samples, and the results of the methods developed were compared.
Resumo:
Absorbance detection in capillary electrophoresis (CE), offers an excellent mass sensitivity, but poor concentration detection limits owing to very small injection volumes (normally I to 10 nL). This aspect can be a limiting factor in the applicability of CE/UV to detect species at trace levels, particularly pesticide residues. In the present work, the optical path length of an on-column detection cell was increased through a proper connection of the column (75 mu m i.d.) to a capillary detection cell of 180 mu m optical path length in order to improve detectability. It is shown that the cell with an extended optical path length results in a significant gain in terms of signal to noise ratio. The effect of the increase in the optical path length has been evaluated for six pesticides, namely, carbendazim, thiabendazole, imazalil, procymidone triadimefon, and prochloraz. The resulting optical enhancement of the detection cell provided detection limits of ca. 0.3 mu g/mL for the studied compounds, thus enabling the residue analysis by CE/UV.
Resumo:
A simple and fast multiresidue method has been developed to determine 48 pesticides within the major groups of pesticides (organohalogen, organophosphorous, pyrethroids and organonitrogen) in representative samples of locally produced honey, in Bauru (State of São Paulo, Brazil) during 2003-2004. The recovery results found ranged from 76% to 95% and the limits of detection were lower than 0.01 mg/kg for gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC-MS-SIM). The results indicated that most pesticides found in the samples belonged to the organohalogen and organophosphorous groups and lower levels of residues of some organonitrogen and pyretroids were also detected. Malathion residues were detected in all the samples, in a high concentration, owing to its applications to control dengue mosquitoes in the area studied. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
The aim of this paper was to apply a multiresidue method using Supercritical Fluid Extraction (SFE) and capillary gas chromatography with electron capture and mass spectrometry detections in the analysis of the levels of pesticide residues in fruits and vegetables. Single laboratory validation of both solid-liquid and supercritical fluid extraction methods was carried out for 32 compounds selected from four pesticide classes (organochlorine, organonitrogen, organophosphorus and pyretroid) in blank and fortified samples of fresh lettuce, potato, apple and tomato. Recoveries for the majority of pesticides from fortified samples at fortification level of 0.04-0.10 mg kg -1 ranged 74-96% for both methods and confirmation of pesticide identity was performed by gas-chromatography-mass spectrometry in a selected-ion monitoring mode. Both methods showed good limits of detection (less 0.01 mg kg-1, depending on the pesticide and matrix) and the SFE method minimized environmental concerns, time, and laboratory work. ©2005 Sociedade Brasileira de Química.