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81.
Joao Felipe Costa 《Computers & Geosciences》2009,35(11):2222-2230
This article investigates an alternative method to deal with data sets in the presence of trends. Median polish kriging (MPK) was introduced as an alternative solution to universal kriging or intrinsic random functions of order k (IRF-k) for estimation in the presence of trends. The maps obtained using the original MPK algorithm show banding artefacts which do not appear in the reference data set. A modified version of MPK was introduced to attempt to remove the banding artefacts. The results confirm the improvement in quality of estimate using the modified version of MPK (called MPKm), which takes into account the problems of clustered samples and boundary effect associated with the re-addition of the trend along bands. The variation introduced in the median polish algorithm proved to be satisfactory in eliminating the artefacts. 相似文献
82.
Alexandre Antunes Ribeiro Rodrigo Fernando Costa Marques Antônio Carlos Guastaldi João Sinézio de Carvalho Campos 《Journal of Materials Science》2009,44(15):4056-4061
Many techniques have been used to coat metallic substrate with bioceramics. The aim of this study was to study the physical-chemical
characteristics of polyvinylidene fluoride (α-PVDF)/hydroxyapatite (HA) composite coating, obtained by casting method, on
commercially pure titanium (α-CP Ti) substrate surface modified by laser beam irradiation. The preparation of coating was
done for mixing α-PVDF pellets shape dissolved in dimethylacetamide (DMA) with HA/DMA emulsion. The mixture was poured onto
the α-CP Ti sample and left to dry in an oven. CP Ti plates were coated with α-PVDF/HA composite film, in proportions of 100/00
and 60/40 in weight, and characterized by particle size analysis, scanning electron microscopy, energy dispersive spectroscopy
(EDS), X-ray diffractometry, thickness measurement and contact angle. Uniform coating with a small thickness variation along
the coated surface was successfully obtained. 相似文献
83.
Leyliane E. Marques Alberth M. C. Costa Murilo C. Crovace Ana C. M. Rodrigues Aluisio A. Cabral 《Journal of the American Ceramic Society》2015,98(3):774-780
In this study, lithium disilicate (LS2) glass samples with different particle sizes ranging from less than 105 to 850 μm were prepared. These specimens were inserted in a Pt‐Rh DSC crucible and heated to 850°C at different rates (? = 0.5–30 K/min) to identify their crystallization peaks. The activation energies for the overall crystallization (E) and the Avrami coefficient (n) were evaluated using different nonisothermal models. Specifically, n was evaluated using the Augis–Benett model and the Ozawa method, and E was evaluated using the Kissinger and Ligero methods. As expected, the coarse particles mainly crystallized in the volume, while surface crystallization was predominant in the samples with particle sizes of less than 350 μm. This result was confirmed through SEM analysis of the double stage heat‐treated samples. In contrast with previous studies, our results demonstrated that the activation energy decreased as the particle size increased. In addition, no clear correlation between the peak intensity (δTp) and the particle size was observed. 相似文献
84.
Oil‐spill cleanup: The influence of acetylated curaua fibers on the oil‐removal capability of magnetic composites 下载免费PDF全文
Eldho Elias Raphael Costa Fernanda Marques Geiza Oliveira Qipeng Guo Sabu Thomas Fernando G. Souza Jr 《应用聚合物科学杂志》2015,132(13)
A magnetic resin based on cardanol, furfural, and curaua fibers was prepared and characterized. The material could be used in oil‐spill cleanup processes, because of its aromatic/aliphatic balance. The resin was prepared through bulk polycondensation of cardanol and furfural in the presence of curaua fibers and maghemite nanoparticles. Hydrophobicity of the curaua fibers was improved by acetylation, increasing the oil‐absorbing capability of the composites. The obtained magnetic composites were studied by Fourier‐transform infrared spectroscopy, X‐ray diffraction, and thermogravimetric analysis. Degree of cure, magnetic force, and oil‐removal capability tests were also performed. The results show that the composites possess an elevated cure degree in addition to a considerable magnetic force. The materials exhibit a good oil removal capability in the presence of a magnetic field, which is improved by the use of acetylated curaua. In the best case, the composite filled with maghemite and curaua can remove 12 parts of oil from water. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41732. 相似文献
85.
This article proposes two Shewhart charts, denoted npxy and npw charts, which use attribute inspection to control the mean vector (μx; μy)′ of bivariate processes. The units of the sample are classified as first‐class, second‐class, or third‐class units, according to discriminate limits and the values of their two quality characteristics, X and Y. When the npxy chart is in use, the monitoring statistic is M = N1 + N2, where N1 and N2 are the number of sample units with a second‐class and third‐class classification, respectively. When the npw chart is in use, the monitoring statistic is W = N1 + 2N2. We assume that the quality characteristics X and Y follow a bivariate normal distribution and that the assignable cause shifts the mean vector without changing the covariance matrix. In general, the synthetic npxy and npw charts require twice larger samples to outperform the T2 chart. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
86.
87.
Maternal Flaxseed Oil During Lactation Enhances Bone Development in Male Rat Pups 总被引:1,自引:0,他引:1 下载免费PDF全文
Aline D’Avila Pereira Danielle Cavalcante Ribeiro Fernanda Carvalho de Santana Aline de Sousa dos Santos Jorge Mancini-Filho Celly Cristina Alves do Nascimento-Saba Luis Guillermo Coca Velarde Carlos Alberto Soares da Costa Gilson Teles Boaventura 《Lipids》2016,51(8):923-929
Flaxseed oil is an alpha linolenic acid source important in the growth and body development stage; furthermore, this acid acts on adipose tissue and bone health. The aim of this study was to evaluate body composition, fatty acid composition, hormone profile, retroperitoneal adipocyte area and femur structure of pups at weaning, whose mothers were fed a diet containing flaxseed oil during lactation. After birth, pups were randomly assigned: control (C, n = 12) and flaxseed oil (FO, n = 12), rats whose mothers were treated with diet containing soybean or flaxseed oil. At 21 days, the pups were weaned and body mass, length, body composition, biochemical parameter, leptin, osteoprotegerin, osteocalcin, fatty acids composition, intra‐abdominal fat mass and femur structure were analyzed. FO showed (p < 0.05): higher body mass (+12 %) and length (+9 %); body fat mass (g, +45 %); bone mineral density (+8 %), bone mineral content (+55 %) and bone area (+35 %), osteocalcin (+173 %) and osteoprotegerin (+183 %). Arachidonic acid was lower (p < 0.0001), alpha‐linolenic and eicosapentaenoic were higher (p < 0.0001). Intra‐abdominal fat mass was higher (+25 %), however, the retroperitoneal adipocytes area was lower (?44 %). Femur mass (+10 %), distance between epiphyses (+4 %) and bone mineral density (+13 %) were higher. The study demonstrates that adequate flaxseed oil content during a lactation diet plays an important role in the development of pups. 相似文献
88.
Roseli de Souza Santos da Costa Flavia da Silva Santos Daniela de Barros Mucci Tânia Vignuda de Souza Fátima Lucia de Carvalho Sardinha Célia Regina Moutinho de Miranda Chaves Maria das Graças Tavares do Carmo 《Lipids》2016,51(12):1363-1373
The purpose of this study was to investigate the trans fatty acids (TFA) content and distribution in colostrum, mature milk, and diet of adolescent mothers, after TFA declaration in food labels became mandatory in Brazil. Participants were healthy adolescents (n 54, 15–19 years, 1–90 days postpartum) practicing exclusive breastfeeding. Milk samples were collected 3 days after delivery (colostrum) and in the third month postpartum (mature milk) by hand expression. The fatty acid composition of the milk samples was determined by gas chromatography. TFA intake corresponded to 1.23 % of total energy value. Total 18:2 TFA accounted for less than 0.5 % of the energy intake. The amount of total 18:1 TFA (mean ± SEM) was 1.9 % ± 0.14 in colostrum and 1.5 % ± 0.2 in mature milk. The total content of n‐3 PUFA was inversely correlated with the total content of 18:1 TFA in colostrum. Both in colostrum and in mature milk, vaccenic acid (11t‐18:1) was found to be the most abundant 18:1 trans isomer, followed by elaidic acid (9t‐18:1), whereas rumenic acid (9c,11t‐18:2 CLA) was the predominant 18:2 trans isomer. In conclusion, the levels of TFA of industrial sources found in the mother's diet and breast milk (colostrum and mature milk) showed a decrease in relation to those observed in studies conducted prior to the TFA labeling resolution in Brazil. However, the current low intake levels of n‐3 LCPUFA and DHA content in the milk of lactating adolescents may be insufficient for supporting adequate neurological development of the infants. 相似文献
89.
Characterization of Crude and Partially Purified Lipase from Geotrichum candidum Obtained with Different Nitrogen Sources 下载免费PDF全文
Rafael Resende Maldonado Eduardo Luiz Pozza Elizama Aguiar-Oliveira Fátima Aparecida Almeida Costa Francisco Maugeri Filho Maria Isabel Rodrigues 《Journal of the American Oil Chemists' Society》2016,93(10):1355-1364
Lipases from Geotrichum candidum were produced in two different medium: A = 12 % (w/v) clarified corn steep liquor (CCSL) + 0.6 % (w/v) soybean oil (SO) and B = 3.5 % (w/v) yeast hydrolysate (YH) + 0.7 % (w/v) SO. Lipases were partially purified from both media by hydrophobic interaction chromatography using 3.0 mol L?1 of NaCl as mobile phase, and they were characterized in the crude and partially purified forms. The recovery of lipase activity from CCSL and YH via HIC were 96 and 94.3 %, and the purification factors were 44.3 and 86.7‐fold, respectively. All evaluated lipases had similar optimum pH (7.0–7.7), but, for the CCSL crude lipase, optimum temperature (47 °C) was 10 °C higher than others lipases evaluated. CCSL crude lipase possessed a higher thermo stability than YH crude lipase, e.g., at 37 °C (pH 7.0) the half‐life of CCSL crude lipase was 19.25 h and at pH 8.0 (30 °C) the half‐life was 48 h, which are five and ten times higher than with YH crude lipase, respectively. On the other hand, the YH crude lipase possessed a higher catalytic constant (kcat = 2.3 min?1) but with almost the same catalytic efficiency (Km/kcat = 32.12 mg mL min?1) in relation to CCSL crude lipase. The lipases differ in biocatalytic properties between substrates, suggesting that the two lipases can be employed for different applications. 相似文献
90.
Systemic administration of a nanoemulsion with tributyrin reduces inflammation in experimental colitis 下载免费PDF全文