Aperfeiçoamento em equipamento para digestão de amostras por via úmida

Aperfeiçoamento em equipamento para digestão de amostras por via úmida. É descrito um aperfeiçoamento em equipamento para digestão de amostras por via úmida que emprega tubos de digestão (20) fechados não encapsulados e aquecimento condutivo que possibilita a rápida decomposição de amostras botânicas, alimentícias, clínicas, ambientais e similares, promovendo um gradiente de temperatura em direção à parte superior do tubo de digestão, permitindo que a temperatura da fase gasosa seja inferior à da fase líquida, de forma que as digestões são realizadas à pressão pouco elevada e, consequentemente, os tubos de digestão utilizados podem ter paredes menos espessas, permitindo o rápido aquecimento e resfriamento das amostras, bem como baixo custo de operação e manutenção, simplicidade, alta frequência analítica,; redução do consumo de reagentes e diminuição da geração de resíduos, dito equipamento provido de um gabinete (10) que evita a contaminação da atmosfera do laboratório por vapores ácidos e a perda dos componentes voláteis da amostra durante o aquecimento

Impacto da energia de micro-ondas na sinterização da zircônia odontológica

Pós-graduação em Odontologia Restauradora - ICT

Preparo do solo e emissão de CO2, temperatura e umidade do solo em área canavieira

Soil tillage is one of the agricultural practices that may contribute to increase the loss of carbon through emission of CO2 (FCO2). The aim of this study was to investigate the effect of three soil tillage systems on FCO2, soil temperature and soil moisture in a sugarcane area under reform. The experimental area consisted of three tillage plots: conventional tillage (CT), conventional subsoiling (CS), and localized subsoiling (LS). FCO2, soil temperature and soil moisture were measured over a period of 17 days. FCO2 showed the highest value in CT (0.75 g CO2 m(-2) h(-1)). Soil temperature presented no significant difference (p > 0.05) between LS (26.2 degrees C) and CS (25.9 degrees C). Soil moisture was higher in LS (24%), followed by CS (21.8%) and CT (18.3%). A significant correlation (r = -0.71; p < 0.05) between FCO2 and soil temperature was observed only in CT. The conventional tillage presented a total emission (2,864.3 kg CO2 ha(-1)) higher than the emissions observed in CS (1,970.9 kg CO2 ha(-1)) and LS (1,707.7 kg CO2 ha(-1)). The conversion from CT to LS decreased soil CO2 emissions, reducing the contribution of agriculture in increasing the concentration of greenhouse gases in the atmosphere.

Quality assessment of eggs packed under modified atmosphere

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

Re-analysis of pluvial precipitation in southern Brazil

This study examined precipitation in southern Brazil based on a data set provided by the Brazilian National Water Agency, covering the period from 1976 to 2010. Data were homogenized using the R software and the Climatol subroutine, which allow completing missing data. Isohyets were drawn using the Geostatistics software to obtain a semivariogram for each analysis. There was a remarkable interannual variability in this region, with positive anomalies in the warm phase (El Nino) and negative anomalies in the cold phase (La Nina) of ENSO. Also, the responses of this variability were not uniform in the entire region, since there was variability from year to year and from event to event.

Determinação da matéria seca e teores de macronutrientes em folhas de frutíferas usando diferentes métodos de secagem

O objetivo desse estudo foi avaliar diferentes métodos de secagem de folhas para três diferentes frutíferas (maracujá, pêssego e abacate), com relação à determinação da matéria seca e os teores foliares de macronutrientes. Foram coletadas amostras de folhas recém expandida de três culturas, do pomar da fazenda de ensino e pesquisa da FCAV-UNESP, câmpus de Jaboticabal, no mês de janeiro de 2010, coletando-se para cada cultura 12 amostras com 25 folhas cada. Os tratamentos constituíram-se por dois métodos de secagem, estufa de circulação de ar forçada regulada a uma temperatura de 70&deg;C e o forno microondas (FMO). Avaliou-se a massa da matéria seca e os teores foliares de macronutrientes. Os resultados sugerem que os dois métodos de secagem testados se assemelham na determinação de matéria seca e nos teores foliares de macronutrientes para as culturas análisadas, exceto os teores de cálcio na cultura do pêssego.

Heat treatment of pre-hydrolyzed silane increases adhesion of phosphate monomer-based resin cement to glass ceramic

This study evaluated the influence of different forms of heat treatment on a pre-hydrolyzed silane to improve the adhesion of phosphate monomer-based (MDP) resin cement to glass ceramic. Resin and feldspathic ceramic blocks (n=48, n=6 for bond test, n=2 for microscopy) were randomly divided into 6 groups and subject to surface treatments: G1: Hydrofluoric acid (HF) 9.6% for 20 s + Silane + MDP resin cement (Panavia F); G2: HF 9.6% for 20 s + Silane + Heat Treatment (oven) + Panavia F; G3: Silane + Heat Treatment (oven) + Panavia F; G4: HF 9.6% for 20 s + Silane + Heat Treatment (hot air) + Panavia F; G5: Silane + Heat Treatment (hot air) + Panavia F; G6: Silane + Panavia F. Microtensile bond strength (MTBS) test was performed using a universal testing machine (1 mm/min). After debonding, the substrate and adherent surfaces were analyzed using stereomicroscope and scanning electron microscope (SEM) to categorize the failure types. Data were analyzed statistically using two-way test ANOVA and Tukey's test (=0.05). Heat treatment of the silane containing MDP, with prior etching with HF (G2: 13.15 ± 0.89a; G4: 12.58 ± 1.03a) presented significantly higher bond strength values than the control group (G1: 9.16 ± 0.64b). The groups without prior etching (G3: 10.47 ± 0.70b; G5: 9.47 ± 0.32b) showed statistically similar bond strength values between them and the control group (G1). The silane application without prior etching and heat treatment resulted in the lowest mean bond strength (G6: 8.05 ± 0.37c). SEM analysis showed predominantly adhesive failures and EDS analysis showed common elements of spectra (Si, Na, Al, K, O, C) characterizing the microstructure of the glass-ceramic studied. Heat treatment of the pre-hydrolyzed silane containing MDP in an oven at 100 °C for 2 min or with hot air application at 50 ± 5 ºC for 1 min, was effective in increasing the bond strength values between the ceramic and resin cement containing MDP.

Avaliação da biodegradação de tolueno por fungos isolados de ambientes associados ao petróleo

Spills can ocurr during oil productive chain and contaminate various environments due to the toxicity of monoaromatics hidrocarbons. Toluene stands out for being agressive to the nervous sistem and teratogenic, with high mobility and solubility in water, which facilitates environmental impact. Studies show that fungi are potential aromatic compounds assimilators, encouraging new researches about its use on the recovery of contaminated sites. This study aimed to select and characterize fungus with potential for biorremediation of toluene. 50 fungi were selected of the Collection of Microorganisms of Interest for Oil Gas and Biofuels, of UNESP Rio Claro, all of which were isolated from sites contaminated with monoaromatic hydrocarbons. Two trials were realized to select the microorganism with greater potential. The first test evaluated fungal growth under toluene saturated atmosphere. 24 fungi were chosen because its greater biomass production to participate in the next trial, the degradation in plates test, where the blue redox agente, DCPIP, indicates the degradation reaction, turning colorless. From this teste was possible to select one isolate which showed higher growth and stronger medium discoloration as the microorganism with the greatest potential to assimilate toluene. The Trichoderma cf. koningii had its potential evaluated through gas cromatography. The experiment proved the efficiency of the methodology, with positives results from the method validation and the effectiveness demonstrated of the LA-PHA-PACK bottles to prevent the volatilization of toluene during the 21 days of experiment. Being reliable its use for monitoring toluene decay associating it with degradation. This results are important because there aren't many methodologies and vials efficient to the purpose of this work. In the present study the degradation rates demonstrated no significant decay of the concentration of hydrocarbon. That may be related to the...

Análise do aporte de sedimentos na bacia hidrográfica do córrego Assistência, SP: caso do Polo Cerâmico de Santa Gertrudes

Pós-graduação em Geociências e Meio Ambiente - IGCE

Efeitos da doxicilina na hipertensão arterial induzida pela exposiçao ao chumbo: quantificação de pepídeos vasoativos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo de manobras evasivas com perturbações orbitais

Pós-graduação em Física - FEG

Eletro-oxidação de metanol e etanol sobre PtAu/C em meio alcalino

The development of electrocatalysts for the oxidation of methanol and ethanol is very important, because these alcohols may be used in the anode fuel cells which convert chemical energy directly into electrical energy with high efficiency, cleanly and with low noise. Thus, this study reports to the synthesis of nanocatalysts of PtAu supported on carbon by microemulsion method. The physical characterization of these catalysts is performed through the techniques of X-ray diffraction and transmission electron microscopy. The catalytic activity of the prepared materials was studied using conventional electrochemical techniques and also the technique of spectro-electrochemical in situ FTIR, which allows identification of intermediates and products of the reactions. From the x-ray diffraction, it was observed that the thermal treatment applied to catalysts favored incorporation of Au into the crystal lattice of Pt,that is, increased the formation of PtAu alloy. Micrographs indicated particle size about 3 nm to materials not heat treated and 9 nm to materials subjected to thermal treatment (heating at 150 ° C for 1h and 30 min in argon atmosphere). Current density oxidation of methanol on PtAu / C were superior to pure platinum. Spectroscopic results indicated the presence of formate in solution in 50:50 and the composition showed bands for CO2, indicating complete oxidation, in lower potential. During ethanol oxidation on the catalyst PtAu, the main product formed was acetate, product of incomplete oxidation. The good performance for methanol oxidation can be attributed to large amounts of oxygen species adsorbed on the catalyst surface, or an electronic effect.

Poluentes orgânicos persistentes em ar interior: desenvolvimento de método de extração em adsorvente para amostragem ativa

Persistent Organic Pollutants (POPs) are chemical substances extraordinarily toxic and persistent in the environment. Due to these properties, POPs are targets of the Stockholm Convention which aims to provide means to eliminate production and use by encouraging the reduction and, where possible, eliminating the release of these contaminants to the environment. One of the articles of this _Convention aims to assess the basal levels of such substances in the environment to monitor both the reduction of release to the environment, and to assess human exposure, using analyzes of milk and air for example. Although efforts to control POPs production and release to the environment have been made, data about their levels in Brazil are still scarce, mainly in the atmosphere or indoor environment. Considering the permanence of people inside its house, this study presents a method for POP extraction from XAD-2 sorbent employed in indoor air sampling, with identification and quantification by GC-ECD. GC-ECD linear range of the studied analytes, congeners of polychlorinated biphenyls (PCB) (28, 52, 101, 118, 138, 153 and 180), DDTs and their metabolites (DDDs, DDEs) and endosullan (isomers c - and 13 - and metabolite endosulfan sulfate) ranged between 0.5 and 16.0 ng mL-I with r2 > 0.967. The method developing consist of selecting the extraction solvent system by agitation (90 rpm, 1 hour) with n-hexan,e (2 mL) or n-hexane:acetone (1:1, v/v) (2 mL), concentration the extract with a gentle N2 stream, and evaluation of breakthrough with passage or air through the fortified XAD-2 cartridge before extraction, employing a low volume air suction pump (Pump Model 224 universal-PCXR8; 5-5000 mL min-1, SKC Inc., Eighty Four, PA, USA), Calibrator Dry-Cal DC-Lite (BIOS, Butler, NJ, USA)). Two fortification levels were employed, 15 and 30 ng. After selecting n-hexane as extraction solvent, with accuracy and precision ranging...

Aplicação de um modelo numérico na otimização de fornos alimentícios usando o OpenFOAM®

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Crescimento econômico e desacoplamento do uso de recursos naturais e de impactos ambientais: evidências para o Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)