Formation of silver chloride nanocrystals as a corrosion product of silver in H2SO4 solution

The purpose of this study is to characterize the corrosion product on the surface of silver, employing H2SO4 (0.5M) as electrolyte. The electrochemical parameters, Ecor, Icor, V cor and Rp were obtained after analyzing the potentiodynamic polarization curve in which two peaks were observed. The smallest (passive region) is attributed to the Cl- traces from the reference electrode, with micro-cracks. The second peak (in the transpassivation region) corresponds to the polarization curve of silver in H2SO 4 without contaminants. SEM images and EDS analysis reveal images of a surface layer on silver, consisting of structures containing sulfur, oxygen, silver and chloride, as the corrosion product. On this layer silver sulfate crystals were observed, which occurs during the formation of silver chloride nanocrystals with different morphologies, when chloride ions were added to the electrolyte medium. ©The Electrochemical Society.

Thermo-gravimetric analysis (TGA) after different exposures of high density polyethylene (HDPE) and poly vinyl chloride (PVC) geomembranes

This paper presents the results of thermogravimetric analysis (TGA) tests in PVC (1.0; 2.0 mm) and HDPE (0.8; 2.5 mm) geomembranes exposed to weathering and leachate after 30 months. The aim of this paper is the comparison of fresh and exposed samples to assess the degradation process concerning the total loss of mass of geomembranes. The exposure was conducted in accordance with the recommendations of ASTM standards. The TGA tests were carried out according to ASTM D6370 and E2105. Results show, for instance, that for PVC geomembrane the largest reductions of plasticizers occurred for samples exposed to weathering. The loss of plasticizers after the exposure contributed to the decrease of deformation and consequent increase in stiffness. TGA tests shows to be a valuable tool to control the quality of the materials. © 2012 ejge.

Short communication: Acute but transient increase in serum insulin reduces messenger RNA expression of hepatic enzymes associated with progesterone catabolism in dairy cows

The objective of this experiment was to evaluate the effects of glucose infusion on serum concentrations of glucose, insulin, and progesterone (P4), as well as mRNA expression of hepatic CYP2C19 and CYP3A4 in nonlactating, ovariectomized cows in adequate nutritional status. Eight Gir × Holstein cows were maintained on a low-quality Brachiaria brizantha pasture with reduced forage availability, but they individually received, on average, 3. kg/cow daily (as fed) of a corn-based concentrate from d -28 to 0 of the experiment. All cows had an intravaginal P4-releasing device inserted on d -14, which remained in cows until the end of the experiment (d 1). On d 0, cows were randomly assigned to receive, in a crossover design containing 2 periods of 24. h each (d 0 and 1), (1) an intravenous glucose infusion (GLUC; 0.5. g of glucose/kg of BW, over a 3-h period) or (2) an intravenous saline infusion (SAL; 0.9%, over a 3-h period). Cows were fasted for 12. h before infusions, and they remained fasted during infusion and sample collections. Blood samples were collected at 0, 3, and 6. h relative to the beginning of infusions. Liver biopsies were performed concurrently with blood collections at 0 and 3. h. After the last blood collection of period 1, cows received concentrate and returned to pasture. Cows gained BW (16.5 ± 3.6. kg) and BCS (0.08 ± 0.06) from d -28 to 0. Cows receiving GLUC had greater serum glucose and insulin concentrations at 3. h compared with SAL cohorts. No treatment effects were detected for serum P4 concentrations, although mRNA expression of CYP2C19 and CYP3A4 after the infusion period was reduced for cows in the GLUC treatment compared with their cohorts in the SAL treatment. In conclusion, hepatic CYP3A4 and CYP2C19 mRNA expression can be promptly modulated by glucose infusion followed by acute increases in circulating insulin, which provides novel insight into the physiological mechanisms associating nutrition and reproductive function in dairy cows. © 2013 American Dairy Science Association.

Design of biogas pipeline - Energy and sanitation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da técnica de evaporação resistiva para a deposição de filmes finos de GaAs e compostos de GaAs com óxidos e cloretos de Er ou Yb

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Avaliação dos parâmetros espermáticos e caracterização do perfil bioquímico do plasma seminal de cães (Canis familiaris – LINNAEUS, 1758) com hiperplasia prostática benigna, tratados com toxina botulínica A

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

Perfil bioquímico, condição microbiológica e celuridade do leite de búfalas

Pós-graduação em Medicina Veterinária - FCAV

Perfil sanguíneo de fêmeas bovinas em gestação e no periparto e avaliação da transferência de imunidade passiva aos descendentes

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

Urolitíase em bovinos da raça Guzerá (Bos taurus indicus): estudo comparativo em animais oriundo de propriedades com e sem o problema

Pós-graduação em Medicina Veterinária - FMVZ

Análise experimental da durabilidade de concretos de alto desempenho com adição de resíduo de borracha de pneu e cinza da casca de arroz

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação dos fatores abióticos e bióticos de uma área petroquímica da região de Paulínia, SP, e fotodocumentação dos fungos transientes isolados

Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC

Caracterização eletroforética do perfil protéico e análise bioquímica do plasma seminal canino

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

Avaliação do comportamento ao desgaste de compósitos poliméricos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reguladores vegetais para o manejo do porte da mamoneira IAC 2028

Pós-graduação em Agronomia (Agricultura) - FCA

Estudo comparativo de algumas provas funcionais do fluido ruminal e de metabólitos sangüíneos de bovinos e bubalinos

No fluido ruminal de búfalos e de bovinos da Região Amazônica, alimentados com capim-elefante (Pennisetum purpureum) var. Cameron, foram determinados os seguintes parâmetros: cor, odor, viscosidade, sedimentação, flotação, pH, redução do azul de metileno, fermentação da glicose, acidez total, número total de protozoários, teor de cloretos, redução de nitrito e grupo de bactérias predominantes. No soro sangüíneo também foram avaliados os teores de cloretos, proteínas totais e uréia. A comparação desses dados não resultou em diferenças significativas entre as duas espécies, com exceção do teor de cloretos e do número e distribuição dos protozoários. Nos búfalos, os teores de cloretos foram mais baixos e o número de protozoários foi maior do que o observado em bovinos; adicionalmente nos búfalos predominaram os protozoários pequenos, enquanto em bovinos preponderaram os protozoários grandes.