Avaliação dos parâmetros de solubilidade de Hildebrand/Hansen na seleção de solventes para a extração de pesticidas organoclorados do solo

This work evaluated the use of the Hildebrand/Hansen solubility parameters for selection of solvents for extraction of the organochlorine pesticides pp' DDT, pp' DDE, Aldrin and a-Endossulfan from soil using columns packed with Al2O3. The mixtures hexane:dichloromethane (7:3; v/v), hexane:acetonitrile (1:1; v/v), hexane:acetone (1:1; v/v) and pure hexane were chosen as extracting solutions. In the addition and recovery tests, different extraction solutions provided high recoveries percentages (>75%) with coefficients of variation below 15%. The recoveries are in agreement with the Hildebrand/Hansen parameters, demonstrating its applicability in the selection of extracting solution and in the replacement of toxic solvents, as dichloromethane

Potencialidades analíticas do dietilditiofosfato de amônio em espectrometria de massas com plasma indutivamente acoplado empregando extração em fase sólida e sistemas de injeção em fluxo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Substâncias húmicas de turfa: estudo dos parâmetros que influenciam no processo de extração alcalina

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

Extração e caracterização do amido de diferentes genótipos de bananeira

A banana, uma das principais herbáceas cultivadas em grande quantidade no mundo e importante fonte de energia para as pessoas, tem obtido interesse como matéria-prima para a produção de farinha e fécula para uso alimentício e outros fins industriais, devido ao elevado conteúdo de amido nos frutos verdes. O trabalho teve como objetivo caracterizar os frutos verdes de sete genótipos de bananeira quanto à composição química e avaliar o conteúdo de amilose, propriedades de pasta e térmicas dos amidos destes genótipos. Os resultados obtidos mostraram diferenças significativas na composição química dos frutos, com maior teor de amido na cultivar Figo Cinza. As análises dos amidos mostraram valores de amilose de 26,68 a 33,95% e propriedades de pasta com elevado pico de viscosidade, baixa resistência à temperatura e agitação (quebra de viscosidade) e tendência à retrogradação para todos os amidos. Nas propriedades térmicas, os amidos mostraram um endoderma, temperatura de gelatinização na faixa de 60 a 73ºC com DH variando de 11,6 a 16,99 J g-1 na gelatinização e 4,11 a 7,97 J g-1 na retrogradação.

Extração por fluido supercrítico de alguns inseticidas carbamatos em amostras de batata, com determinação por HPLC/fluorescência e confirmação por HPLC/espectrometria de massas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Métodos de extração e determinação do herbicida glifosato: breve revisão

This paper supplies a compact revision about the main extraction, clean-up and pre-concentration methods of the herbicide glyphosate for water and soil samples, as well as methods for its determination and quantification.

Extração de amônio de filtros de amostragem, coleta e determinação pelo método da gota suspensa

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

Potencialidade energética em diferentes extratores e tempos de extração do óleo de pinhão-manso (jatropha curcas l.) em soxletter

The current rhythm of petroliferous exploration is esteem that the existing reserves will be depleted in next the 45 years. Thus being, it has that to study intensely, what it has come to be fact, the alternative power plants, as well as the technologies economically capable to ultilizar them. The potential demand of biodiesel for 2020 is taken in consideration that, in accordance with the International Agency of Energia (AIE), in only eight countries, will jump of 34,7 million tons in 2010 for 133,8 million in 2020, with an increment next to 300%. The tame nut is a producing oil plant with all the qualities necessary to be transformed into oil diesel. Beyond perennial and of easy culture, it presents good conservation of the harvested seed, being able to become great producer of substance cousin as optional fuel source. For these authors, this is a culture that can be developed in the small properties, with the available familiar man power, being plus a source of income for the country properties of the Northeast Region. The objective of this work is to evidence the capacity of oil production of the nut-bellwether, and the quality of extration with hexano and methanol in 6 distinct times.

Efeitos da estimulação ultra-sônica sobre o processo de reparo em ferida de extração dental: estudo histológico em ratos.

The effects of ultrasound on the wound healing process after teeth extractions were studied histologically. The right upper incisor was extracted in 56 rats. They were divided into 2 groups, one control (I) and one experimental (II). Group II received ultrasound stimulation that was applied with the frequency of repetition of 1,000 Hz and pulse length of 2,000 us continuously, during five minutes daily since the extraction day until 24 hours before the death. The rats were sacrificed at 3, 6, 9, 12, 15, 18, and 21 postoperative days. The results showed a precocious granulation tissue formation, faster remodeling of osseous ridges, and consequently acceleration of the alveolar wound healing process.

Efeito de parâmetros analíticos sobre a precisão de métodos de extração de zinco do solo

Fifteen soil samples and four extradants (DTPA, Na 2EDTA, HCl and Mehlich 1) were used to study soil extraction methods for available zinc. Each extradant was studied in three soil:solution ratios (1:2, 1:4 and 1:10) and in three extraction periods in the ratio most frequently used. The zinc extracted by DTPA, Na 2EDTA and HCl was not affected by use of soil:solution ratios 1:2 and 1:4, but the amount extracted increased with the 1:10 ratio. In this relation, the variation coefficients increased. With Mehlich, no definite tendency was observed. The increase of extraction period for DTPA extractant, in 1:2 ratio, had little effect on the amount of zinc extracted and on the precision. As to Na 2EDTA extractant in 1:10 ratio, with the increase of extraction time, both increased. As to HCl and Mehlich, both in 1:4 ratio, the increase in extraction period had no effect on the amount of zinc extracted and no definite effect on the precision. Thus, the use of 1:2 ratio for DTPA and Na 2EDTA and 1:4 ratio for acid extractants is recommended. Concerning the period of extraction, 120 min should be used with DTPA and Na 2EDTA, 15 min with HCl and 5 min with Mehlich.

Comparação de dois métodos de extração de Xanthomonas campestris pv. phaseoli em sementes de feijoeiro

The objective of this research was to evaluate the effectiveness of the extraction of Xanthomonas campestris pv. phaseoli from naturally infected dry bean seeds. Extraction methods tested included soaking whole seeds in sterilized saline phosphate buffer and crushing seeds after soaking in sterilized saline phosphate buffer. The bacterium was isolated on a semiselective agar medium. The seed crushing method was found to be more effective. The bacterium strains isolated were pathogenic to bean leaves, reacted with X. campestris pv. phaseoli antiserum, and had morphological and physiological/biochemical characteristics typical of the X. campestris pv. phaseoli.

Extração de matéria orgânica aquática por abaixamento de temperatura: Uma metodologia alternativa para manter a identidade da amostra

In this work was developed an alternative methodology to separation of aquatic organic matter (AOM) present in natural river waters. The process is based in temperature decreasing of the aqueous sample under controlled conditions that provoke the freezing of the sample and separation of the dark extract, not frozen and rich in organic matter. The results showed that speed of temperature decreasing exerts strongly influence in relative recovery of organic carbon, enrichment and time separation of the organic matter present in water samples. Elemental composition, infrared spectra and thermal analysis results showed that the alternative methodology is less aggressive possible in the attempt of maintaining the integrity of the sample.

Extração de feições rodoviárias em imagens digitais: Metodologias desenvolvidas pelo GP-F&VC

Several kinds of research in road extraction have been carried out in the last 6 years by the Photogrammetry and Computer Vision Research Group (GPF&VC - Grupo de Pesquisa em Fotogrametria e Visão Computacional). Several semi-automatic road extraction methodologies have been developed, including sequential and optimizatin techniques. The GP-F&VC has also been developing fully automatic methodologies for road extraction. This paper presents an overview of the GP-F&VC research in road extraction from digital images, along with examples of results obtained by the developed methodologies.

Extração semi-automática de rodovias em um par de imagens aéreas digitais utilizando geometria epipolar e programação dinâmica

The purpose of this paper is to introduce a methodology for semi-automatic road extraction from aerial digital image pairs by using dynamic programming and epipolar geometry. The method uses both images from where each road feature pair is extracted. The operator identifies the corresponding road featuresand s/he selects sparse seed points along them. After all road pairs have been extracted, epipolar geometry is applied to determine the automatic point-to-point correspondence between each correspondent feature. Finally, each correspondent road pair is georeferenced by photogrammetric intersection. Experiments were made with rural aerial images. The results led to the conclusion that the methodology is robust and efficient, even in the presence of shadows of trees and buildings or other irregularities.

Alterações dentoesqueléticas e do perfil facial em pacientes tratados ortodonticamente com extração de quatro primeiros pré-molares

Objective: the purpose of this prospective study was to cephalometrically analyze the dentoalveolar and soft tissue changes after the orthodontic treatment followed by the extraction of four premolars. Material and methods: the sample was comprised by 30 Class II division 1 patients with mean initial age of 12 years and 4 months. Two lateral cephalograms were obtained from each patient at the beginning and at the end of the treatment. The variables analyzed were the nasalabial changes and upper and lower incisors changes in relation to a vertical and horizontal x and y reference lines. Results: upper and lower incisors retraction was 3.4 and 1.8mm, respectively. The SNA angle was decresead by 1.7 degrees followed by a retraction of point A mainly due to the upper incisor retraction. There was a significant decrease of the Wits and ANB variables. There was an increase in the lower anterior facial height. Upper incisor retraction was followed by an increase in the nasolabial angle (ratio 1:2.8 degrees). However, a wide range of individual variability was found. Conclusions: the present study did not support the simple expectation that treatment with extractions of four premolars will result in a dished in face. It appeared that facial changes were more related to a normal facial growth, the amount of incisor retraction and the anchorage control during the upper and lower incisor.