Electrochemical behaviour of copper electrode in concentrated sulfuric acid solutions

The electrochemical behaviour of copper in 6.0 mol 1-1 sulfuric acid at 30°C, was studied by means of the potentiodynamic method. At low potential sweep rates, v < 200 m V s-1, the data reveal that the anodic process is basically constituted of copper dissolution and a film formation which inhibits further metal oxidation and which may undergo further dissolution. For higher potential sweep rates, a modification in the passivation region of the voltammogram is observed. It can be ascribed to a change in the passivation mechanism which possibly involves different surface species. The kineticrelationships derived from the potentiodynamic I/E curves obtained at low v suggest a film formation via a dissolution/precipitation mechanism. © 1993.

Identificação e caracterização de metagenomas e isolados bacterianos visando a biorremediação de solos de áreas de mineração

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

Control of bacterial spot of tomato and activation of enzymes related to resistance by chemicals under field conditions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Production of alcoholic beverage from ginger: study of fermentation process and final product quality

Introduction: In Brazil part of the production of ginger is of inadequate quality for export. The production of spirit from felt-over rhizomes is an alternative of great interest to producers of these rhizomes. Aim: Aiming to increase the value of felt-over rhizomes, this work aimed to study the use of ginger as a raw material for alcoholic beverage production. It was evaluated the effect of fermentation conditions on the components of fermented alcoholic, as well as, the quality of alcoholic distilled beverage of ginger. Methods: Dehydrated ginger passed by enzymatic hydrolysis-saccharification processes. The hydrolysate obtained was analyzed for sugar profile in HPLC. The alcoholic fermentation process followed the central composite rotational design for three factors: fermentation temperature (23 to 37ºC), time of fermentation (17 to 33 h) and concentration of inoculum (0.22 to 3.00%). The fermented alcoholic obtained was analyzed in HPLC for the contents of ethanol, methanol, glycerol and residual sugars. The distillated alcoholic beverage of ginger was analyzed for ethanol, methanol, acetaldehyde, ethyl acetate and higher alcohols in the gas chromatography (GC). In addition, copper content and acidity were analyzed Results: Sugar profile of the ginger hydrolysate revealed the presence of 77.8% of glucose. Data analysis of fermentation process showed influence of temperature on ethanol and methanol content of the fermented alcoholic of ginger. Time of fermentation had effect on glycerol content. All parameters of process had influence on residual sugars contents. The HPLC analysis has shown presence of methanol, ethyl acetate, aldehyde, acids, higher alcohols and esters in distilled alcoholic beverage of ginger. Conclusion: Fermented alcoholic of ginger with higher levels of ethanol can be obtained under the conditions of 1.5% w/w of inoculum, 30°C of temperature and 24 hours of fermentation time. In this condition of fermentation process the beverage of ginger had good quality.

Proteinograma e teores de cobre, ferro e zinco no soro sanguíneo de ovelhas da raça Santa Inês com mastite experimental por Staphylococcus aureus

Costa N.A., Simao L.C.V., Santos R.A., Afonso J.A.B., Fagliari J.J., Cardoso E.C., Soares P.C. & Mendonca C.L. 2010. [Proteinogram and serum concentrations of copper, iron and zinc in Santa Ines ewes with Staphylococcus aureus experimentally induced mastitis.] Proteinograma e teores de cobre, ferro e zinco no soro sanguineo de ovelhas da raca Santa Ines com mastite experimental por Staphylococcus aureus. Pesquisa Veterinaria Brasileira 30(5):435-442. Clinica de Bovinos, Campus Garanhuns, Universidade Federal Rural de Pernambuco (UFRPE), Avenida Bom Pastor s/n, Boa Vista, Caixa Postal 152, Garanhuns, PE 55292-901, Brazil. E-mail: carlalopes.mendonca@gmail.comThe aim of the present study was to evaluate the effect of Staphylococcus aureus experimentally induced mastitis on proteinogram and serum concentrations of cupper, iron and zinc levels of Santa Ines primiparous ewes. The right mammary gland of ten healthy ewes was inoculated with 1,0x10(4) UFC/mL of S. aureus. Clinical examination and determination of serum concentrations of proteins by electrophoresis in polyacrylamide gel (SDS-PAGE), cupper, iron and zinc, as well plasma level of fibrinogen were measured before the inoculation (control) and 12h, 24h, 36h, 48h, 60h, 72h, 84h, 96h, 108h, 120h, 132h, 168h, 180h, 288h and 336h after bacteria inoculation. All animals experimentally infected presented clinical mastitis and subsequent loss of mammary gland function. The electrophoretogram allowed the identification of 23 proteins with molecular weights (MW) ranged from 26.000 to 185.000 daltons (Da) including acute-phase proteins, IgG and IgA. A significant increase (P<0,05) in haptoglobin, ceruloplasmin, IgG and IgA concentrations was observed. Antitrypsin and acid glicoprotein concentrations did not alter. The levels of iron and zinc decreased and the cupper concentration increased. A positive correlation between plasma fibrinogen and serum ceruloplasmin (r=0.74), haptoglobin (r=0.62) and IgA (r=0.62) was also identified. Results showed the importance of ceruloplasmin and haptoglobin as acute-phase proteins in ewes with intramammary infections and confirms fibrinogen as an inflammatory marker because its high correlation with specific proteins. The alterations in the serum levels of Cu, Fe and Zn suggest the action of inflammatory mediators triggered by S. aureus.

Biofertilizer for control of Guignardia citricarpa, the causal agent of citrus black spot

Biofertilizers generated from the anaerobic and aerobic digestion of cattle manure, known as Bio1 and Bio2, respectively, were studied with regard to their microbial composition and effect on the mycelial growth of Phyllosticta citricarpa, the causal agent of citrus black spot (CBS). Two field experiments were conducted to determine the biofertilizer's potential (Bio1) in controlling CBS (2001/2002 and 2002/2003 crops). It was observed that the greatest number of microorganisms was found in the aerobically produced biofertilizer. Bio2 did not inhibit the mycelial growth of P. citricarpa. Mycelial growth of P. citricarpa was inversely proportional to the Bio1 biofertilizer concentration. In the 2001/2002 cropping season, the Biol effect in controlling CBS was directly proportional to its concentration, at the rate of 0 (healthy fruit), with R-2 = 0.88. Biol had a significant effect in controlling CBS, at a concentration of 10%, during the 2001/2002 cropping season, with DI values of 0.246 and 0.229 for the. 10 and 20% doses, respectively, compared to DI of 0.329 for the control. A directly proportional effect of the biofertilizer concentration on the percentage of fruits with a rating of zero was. also observed in the 2002/2003 cropping season, with R-2 = 0.48. However, even at doses higher than in the preceding cropping season, the biofertilizer was less effective, possibly due to a higher occurrence of the disease. Copper oxychloride and combined applications of copper oxychloride and carbendazim plus mancozeb controlled the disease. The possibility of using the biofertilizer as a protective biofungicide to replace copper oxychloride, especially in organic agriculture, should be explored. (c) 2005 Elsevier Ltd. All rights reserved.

Segurança das condições de aplicação de herbicidas com aerobarco em plantas daninhas aquáticas no lago da Hidrelétrica de Jupiá

Os objetivos deste trabalho foram quantificar as exposições dérmicas (EDs) e respiratórias (ERs) proporcionadas ao piloto e ao seu ajudante nas aplicações de herbicidas para o controle de plantas daninhas aquáticas com aerobarco; classificar essas condições de trabalho em seguras ou inseguras; e calcular a necessidade de controle das exposições (NCE) e o tempo de trabalho seguro (TTS). O aerobarco utilizado tinha casco de alumínio (4,85 x 2,42 m) e acionamento por hélice acoplada a motor a gasolina de 350 HP. O equipamento de pulverização era composto por bomba de diafragma com fluxo máximo de 49,69 L min-1, pressão máxima de 25 kg cm-2, acionada por motor a gasolina de 4 HP, e tanque de calda de 189 L. A barra de pulverização de alumínio era composta de duas seções laterais de 3 m, posicionadas na linha entre o encosto do banco do piloto e o início da estrutura protetora da hélice. Cada seção da barra tinha seis bicos com pontas de jato plano com indução de ar AI 100 03, espaçados de 0,5 m, e uma ponta OC 20 fixada em cada extremidade. O conjunto de pontas pulverizava faixas de 6 m de largura e aplicava o volume de calda de 200 L ha-1. O sistema tinha gerenciador de fluxo, controlado por central eletrônica acoplada a DGPS (com precisão submétrica), para corrigir automaticamente a vazão em função de alterações na velocidade real da embarcação. As EDs e ERs aos herbicidas foram calculadas com os dados substitutos das exposições às caldas, avaliadas com os traçadores cobre e manganês adicionados às caldas. As exposições foram extrapoladas para uma jornada de trabalho de seis horas. A segurança das condições de trabalho foi determinada com o cálculo da margem de segurança (MS), utilizando-se a fórmula MS = (NOEL x 70)/(QAE x 10), em que QAE = quantidade absorvível da exposição. As condições de trabalho foram classificadas em seguras, se MS>1, ou inseguras, se MS<1. As exposições proporcionadas pelas condições de trabalho foram de 10,65 mL de calda por dia para o piloto e de 16,80 mL por dia para o ajudante, que fica sentado em uma cadeira a 2,0 m à frente do piloto e da barra de pulverização. Classificaram-se como seguras as aplicações dos herbicidas glyphosate (Rodeo, 6 L ha-1), 2,4D (DMA 806 BR, 8 L ha-1) e fluridone (Sonar AQ, 0,4 L ha-1), para o piloto e o seu ajudante. Classificou-se como insegura a aplicação do herbicida diquat (Reward, 4,0 L ha-1) para as duas condições de trabalho, cujas necessidades de controle das exposições calculadas foram de 65% para o piloto e de 78% para o ajudante do piloto.

Eficiência e custo do controle químico da mancha de alternaria em tangor murcote

A mancha de alternaria, causada por Alternaria alternata f. sp. citri, afeta tangelos Minneola, tangerinas Dancy, tangores Murcote e, menos freqüentemente, tangelos Orlando, tangerinas Novas, Lees e Sunburst. Esta doença causa desfolha grave, queda de frutos e manchas nas frutas. O objetivo deste trabalho foi estabelecer o melhor fungicida e a melhor dose para o controle da mancha marrom de alternaria. O delineamento experimental foi de parcelas subdivididas em blocos, com 10 tratamentos principais e 3 doses (subparcelas), com 5 repetições. Foram feitas 5 aplicações, com intervalo de 15 dias. Os tratamentos foram: azoxystrobin, pyraclostrobin, trifloxystrobin, trifloxystrobin + tebuconazole (2 aplicações) seguido de 3 aplicações de mancozeb, difenoconazole, trifloxystrobin + propiconazole, iprodione, trifloxystrobin + propineb (2 aplicações) seguido de 3 aplicações de oxicloreto de cobre, oxicloreto de cobre + óleo e testemunha. Simultaneamente foram feitas avaliações de incidência e número de lesões por folha. Ao surgimento dos frutos foram avaliadas a incidência em frutos e a produtividade em Kg/ha. Todos os tratamentos foram superiores à testemunha quanto a produtividade. Entre os produtos utilizados o tratamento com trifloxystrobin + propiconazole foi rentável comparando-se custo e produtividade.

Análise de sobrevivência aplicada ao desenvolvimento do pulgão Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) em plantas de pepino (Cucumis sativus L.) contaminadas com fungicidas

It was aimed to evaluate the influence of fungicides utilized in cucumber on the development of the aphid Aphis gossypii Glover under greenhouse conditions. The experimental design was completely randomized with four treatments and 45 replicates, being each plot consisting of a first instar nymph coming from an apterous female in early reproductive period. The fungicides utilized and their respective dosages at g i.a.L(-1) were 800 PM sulphur (1.6), 800 PM mancozeb (1.6) and 840 PM copper oxichloride (1.5). The control was made up of water only. The products did not influence the median time of life in each instar and the nymphal stage, being respectively 1 and 4 days. Copper oxychloride and mancozeb increased the median time of life in days and the total life cycle of the adult stage of this species.

Correlação entre a atividade sérica da ceruloplasmina e os teores sérico e hepático de cobre em novilhas Nelore

Avaliou-se a atividade oxidativa sérica da ceruloplasmina como indicadora dos teores sérico e hepático de cobre e compararam-se dois métodos de determinação da ceruloplasmina, pelo parafenileno e pela ortodianisidina. Foram colhidas 56 amostras de soro e de fígado (biópsias hepáticas) de novilhas Nelore para determinação da atividade sérica da ceruloplasmina e da concentração de cobre. As correlações entre a concentração sérica de cobre e a atividade sérica da ceruloplasmina determinadas pelos métodos do parafemileno e da ortodianisidina foram 0,75 e 0,62, respectivamente. As correlações entre a concentração hepática de cobre e a atividade sérica da ceruloplasmina pelos métodos citados foram 0,15 e 0,12. Não foi observada correlação entre os valores séricos e hepáticos de cobre. A correlação entre determinação da atividade sérica de ceruloplasmina, que utilizou o parafenileno como substrato, e o cobre sérico foi maior do que a correlação entre esse mineral e o método que usou a ortodianisidina.

A review of complete albinism in bats with five new cases from Brazil

Complete albinism is a rare phenomenon that occurs in all vertebrate groups. In bats, albinism has been recorded in several species but this information has not previously been reviewed in detail nor has there been an analysis of its importance. In this study, cases of albinism from the literature are checked and new cases are presented. Complete albinism in bats is documented in eight families, 38 species, and at least 64 individuals (47.4% female female and 52.6% males; n = 38). of these, 39 individuals were observed and/or captured in sheltered roosts, such as caves (51.3%), mines and galleries (20.5%), buildings (17.9%), and hollow-trees and bird boxes (7.7%). Only one albino bat (2.6%) was captured in an external roost (foliage). This individual is the fruit bat, Artibeus planirostris, which is recorded here for the first time. Information on four additional cases of albino individuals of the common vampire bat, Desmodus rotundus, is also presented. It is suggested that sheltered roosts favour survival of albino bars, offering protection against sunlight, water loss, and visually hunting predators.

AC impedance study of Ni, Fe, Cu, Mn doped ceria stabilized zirconia ceramics

Doped zirconia has been used in electronic applications in the cubic crystalline phase. Ceria-stabilized tetragonal zirconia presents high toughness and can also be applied as solid electrolytes. The tetragonal phase of zirconia can be stabilized at room temperature with ceria in a broad range of composition. However, CeO2-ZrO2 has low sinterability. so it is important to investigate the effect of sintering dopants. In this study the effect of iron, copper. manganese and nickel was investigated. The dopants such as iron and copper lowered the sintering temperature from 1600 degreesC down to 1450 degreesC, with a percentage of tetragonal phase retained at room temperature higher than 98% and also with an increase of the electrical conductivity. The electrical conductivity was measured using impedance spectroscopy. The grain boundary contribution was determined and the activation energy associated with the ionic conduction was 1.04 eV. The dopants can also promote a grain boundary cleanliness verified by blocking effect measurement. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Electrical measurements in doped zirconia-ceria ceramics

Zirconia-ceria powders with 12 mol % of CeO2 doped with 0.3 mol% of iron, copper, manganese and nickel oxides were synthesized by the conventional mixed oxide method. These systems were investigated with regard to the sinterability and electrical properties. Sintering was studied considering the shrinkage rate, densification, grain size, and phase evolution. Small amount of dopant such as iron reduces sintering temperature by over 150degreesC and more than 98% of tetragonal phase was retained at room temperature in samples sintered at 1450degreesC against 1600degreesC to stabilize the tetragonal phase on pure ZrO2-CeO2 system. The electrical conductivity was measured using impedance spectroscopy and the results were reported. The activation energy values calculated from the Arrhenius's plots in the temperature range of 350-700degreesC for intragrain conductivities are 1.04 eV.

Biossorção de cobre, manganês e cádmio por biomassas de Saprolegnia subterranea(Dissmann) R.L. Seym. e Pythium torulosumCoker & P. Patt. (Oomycetes)

Dried biomass of the zoosporic fungi Saprolegnia subterranea and Pythium torulosum was evaluated for copper, manganese and cadmium biosorption from aqueous solutions using the "q" (mg of adsorbed metal per g of biomass) and the "R%" (percent removal) indices. The highest q values were observed when the biomass was placed in contact with high metal concentrations, whereas the highest R% values were observed at low concentrations (p< 0.05). S. subterranea SPC 1244 biomass surpassed the others for copper biosorption (q = 7.48 mg/ g; R% = 49.03), P. torulosum SPC 1425 biomass was the best for manganese biosorption (q = 4.13 mg/g; R% = 26.71), and S. subterranea SPC 1431 biomass was the best for cadmium biosorption (q = 6.75 mg/g; R% = 42.26). This is the first report on copper, manganese and cadmium biosorption by the biomass of these zoosporic fungi, indicating the potential to remove ions from diluted solutions.

Study of environmental burden of lead in children using teeth as bioindicator

The south region of São Paulo city hosts the Guarapiranga dam, responsible for water supply to 25% of the city population. Their surroundings have been subject to intense and irregular occupation by people from very low socioeconomics classes. Measurements undertaken on sediment and particulate materials in the dam revealed concentrations of lead. copper, zinc and cadmium above internationally accepted limits. Epidemiological and toxicological studies undertaken by the World Health Organization in individuals exhibiting lead concentrations in blood, near or below the maximum recommended (10 mu g dl(-1)), surprisingly revealed that toxic effects are more intense in individuals belonging to low socioeconomics classes. Motivated by these facts, we aimed at the investigation of chronic incorporation of lead. as well as the use of our BIOKINETICS code, which is based on an accepted ICRP biokinetics model for lead, in order to extrapolate the results from teeth to other organs. The focus of our data taking was children from poor families, living in a small, restrict and allegedly contaminated area in São Paulo city. Thus, a total of 74 human teeth were collected. The average concentration of lead in teeth of children 5 to 10 years old was determined by means of a high-resolution inductively coupled plasma mass spectrometer (ICP-MS). For standardization of the measurements, an animal bone certified material (H-Animal Bone), from the International Atomic Energy Agency, was analyzed. The amount of lead in children living in the surroundings of the dam, was approximately 40% higher than those from the control region, and the average lead concentration was equal to 1.3 mu g g(-1) approximately. Grouping the results in terms of gender, tooth type and condition, it was concluded that a carious molar of boys is a much more efficient contamination pathway for lead, resulting in concentrations 70% higher than in the control region. We also inferred the average concentrations of lead in other organs of these children, by making use of our BIOKINETIC code. (C) 2008 Elsevier Ltd. All rights reserved.