排序方式: 共有18条查询结果,搜索用时 15 毫秒
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Janete Deliberali Freo Neiva Deliberali Rosso Lidiane Borges Dias de Moraes Álvaro Renato Guerra Dias Moacir Cardoso Elias Luiz Carlos Gutkoski 《Journal of Stored Products Research》2011,47(4):316-320
This study was done to evaluate the physicochemical properties and to quantify the residual silicon in flour from wheat grains treated with different dosages of DE and stored in a conventional system for 180 days. Samples containing 10.0 kg of wheat grain were treated with 0.00, 2.00 and 4.00 g kg−1 of DE and then homogenized and stored in cotton bags at 22 °C and 70 ± 5 g 100 g−1 relative humidity. Physicochemical analyses were carried out at 0, 60, 120 and 180 days of storage. The experiment was conducted in a randomized design with a factorial 3 × 4 arrangement (three doses of DE × four storage periods), totaling 12 treatments, with three replicates for each treatment. The wheat flour samples were digested and the silicon residue quantification was conducted through colorimetry. The wheat treated with DE presented a lower test weight compared with control, +b∗ chromaticity coordinate for color and increased ash content and L∗. The physicochemical changes in the grain and wheat flour were proportional to the amount of DE applied. 相似文献
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Renata U. Ribeiro Janete W.C. Liberatori Herbert Winnishofer Jos Maria C. Bueno Daniela Zanchet 《Applied catalysis. B, Environmental》2009,91(3-4):670-678
Colloidal Co nanoparticles with sizes in the 3–8 nm range were obtained by thermal decomposition of Co2(CO)8 in the presence of ligands and impregnated on SiO2 to prepare SiO2-supported Co nanocatalysts. The catalysts showed activity for the steam reforming of ethanol with higher values for smaller Co particles. H2 adsorption results and Fourier transform infrared spectroscopy of adsorbed CO suggested that the fraction of accessible Co sites also depended on the synthesis conditions. Precipitation of the Co nanoparticles with methanol instead of ethanol before impregnation had a positive effect on the density of accessible Co sites to catalysis; similar result was verified by increasing the thermal treatment temperature under H2 flow before the reaction. Based on the distribution of products with temperature of reaction, a mechanism for steam reforming of ethanol on SiO2-supported Co nanocatalysts is suggested. 相似文献
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Luzia Shundo Adriana P. de Almeida Janete Alaburda Leda C.A. Lamardo Sandra A. Navas Valter Ruvieri Myrna Sabino 《Food Control》2009,20(12):1099-1102
Seventy paprika samples collected in the city of São Paulo, Brazil, from January to April 2006 were analysed for aflatoxins and ochratoxin A (OTA) using an immunoaffinity column clean-up and HPLC-FLD. For aflatoxins, the limit of quantification (LOQ) were 0.23, 0.23, 0.45 and 0.45 μg/kg for AFB1, AFB2, AFG1 and AFG2, respectively. For OTA the LOQ was 0.80 μg/kg. Aflatoxins were found in 82.9% of samples and AFB1 was detected in 61.4% at levels ranging from 0.5 to 7.3 μg/kg with mean concentration of 3.4 μg/kg. OTA was found in 85.7% at levels ranging from 0.24 to 97.2 μg/kg with mean concentration of 7.0 μg/kg. 相似文献
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Israel Krindges Raquel Andreola Cláudio A. Perottoni Janete E. Zorzi 《International Journal of Applied Ceramic Technology》2008,5(3):243-248
Injection molding has important advantages over other methods for the production of advanced ceramic parts with complex shapes. In this work, low-pressure injection molding was used to produce helical ceramic springs using two different kinds of molds. The ceramic powders used were submicrometer-sized alumina and partially stabilized zirconia. Sintered alumina and zirconia springs were obtained free of defects, with densities from 96% to 99% of the theoretical value. In preliminary mechanical tests, these ceramic springs supported axial deformations up to 10% before failure. 相似文献
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In this work we investigate the acetaldehyde electrooxidation reaction on PtRh electrodeposits as a function of their composition. Potentiodynamic results show that the balance between CO2 and acetic acid pathways depends on the PtRh composition. By using in situ FTIR we interpret this dependence in terms of a dual role played by Rh during acetaldehyde electrooxidation. Rh seems to favor the break of C–C bonds (favoring the production of CO2) whilst prevents the deliverance of oxygen-containing species, thus inhibiting the oxidation steps. 相似文献
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Luiza Felippi de Lima Cláudio Antônio Perottoni Janete Eunice Zorzi Robinson Carlos Dudley Cruz 《International Journal of Applied Ceramic Technology》2021,18(6):1950-1959
Basalt glasses may form glass-ceramic materials upon a thermal treatment (TT) if the Fe2O3/FeO ratio is greater than 0.5. In this work, a Serra Geral Formation basalt was used to produce different glass-ceramic materials by changing its chemical composition, removing Fe2O3 via magnetic separation and adding 20 wt% Fe2O3. Glass-ceramics were prepared by melting at 1500°C, followed by a crystallization plateau at 950°C. This petrurgic TT yields dendritic structures upon surface crystallization. With the increase of the iron content, crystallization was more pronounced, as observed in thermal analysis results and optical/scanning electron microscopy. The microstructure analysis shows that these glass-ceramics exhibit at least two different types of crystallization. On the surface, the predominant crystallization was dendritic, while in bulk, crystallization occurred in the form of randomly distributed submicrometric spheroid crystals. 相似文献
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Lucion Aldo B.; Pereira Francine M.; Winkelman Elisa C.; Sanvitto Gilberto L.; Anselmo-Franci Janete A. 《Canadian Metallurgical Quarterly》2003,117(5):894
Neonatal handling induces long-lasting effects on behaviors and stress responses. The objective of the present study was to analyze the effects of neonatal handling (from the 1st to the 10th day after delivery) on the number of cells and volume of locus coeruleus (LC) nucleus in male and female rats at 4 different ages: 11, 26, 35, and 90 days. Results showed significant reductions in the number of cells and the volume of the LC nucleus in neonatally handled males and females compared with nonhandled rats. Environmental stimulation early in life induced a stable structural change in a central noradrenergic nucleus, which could be one of the causal factors for the behavioral and hormonal alterations observed in adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Carolina Cavion Júlia Tonet Luísa de S. Miola Cláudio A. Perottoni Janete E. Zorzi 《International Journal of Applied Ceramic Technology》2019,16(1):400-403
In the context of ceramics production, the purpose of drying is to remove water from a ceramic body after forming. Drying should be performed at an appropriate rate, at an acceptable cost, and in such a way as not to damage the ceramic body. Although the determination of the best drying conditions is critical to ceramics production, the experimental determination of drying parameters, particularly of the critical moisture content, use to be very subjective. In this work, we propose an empirical mathematical expression, based on the generalized logistic model, which is capable of describing the complete drying curve. The critical moisture is thus unambiguously obtained as the intersection point of two straight lines derived from the mathematical modeling of the full drying curve. The heuristic proposed in this work may find particular application in automated procedures, data acquisition, and analysis of drying curves of ceramic masses. 相似文献
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Maria Luiza Zeraik Didier Serteyn Ginette Deby-Dupont Jean-Nöel Wauters Monique Tits Janete H. Yariwake Luc Angenot Thierry Franck 《Food chemistry》2011
The antioxidant activity of methanol extracts from Passiflora edulis and Passiflora alata pulp, and P. edulis rinds, healthy or infected with the passion fruit woodiness virus (PWV), was investigated using the oxidant activities of the neutrophil and the neutrophil granule enzyme myeloperoxidase (MPO), both playing key roles in inflammation. The reactive oxygen species produced by stimulated neutrophils were evaluated by lucigenin-enhanced chemiluminescence (CL) and the activity of purified MPO was measured by SIEFED (Specific Immunological Extraction Followed by Enzymatic Detection), a technique for studying the direct interaction of a compound with the enzyme. The rind extracts of P. edulis possessed higher and dose-dependent inhibitory effects on CL response and on the peroxidase activity of MPO than total pulp extracts from both passion fruit species. The quantification of isoorientin in the extracts showed a correlation with their antioxidant activity, suggesting the potential of P. edulis rinds as functional food or as a possible source of natural flavonoids. 相似文献