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81.
Valdecir Antoninho Dalpasquale Dcio Sperandio Luiz Henry Monken e Silva Evandro Kolling 《Applied mathematics and computation》2008,200(2):590
This work is concerned with the numerical simulation of fixed-bed corn drying using MSU (Michigan State University) drying model. The classical numerical procedure for MSU model relies on an explicit method of finite differences which requires certain stability conditions between the step sizes of the time and space variables. The objective of the present paper is to establish a stable implicit method based on backward finite differences, in both time and space variables, which takes into account some specific empirical aspects of the problem. Computational results illustrate the efficiency and the flexibility of method. 相似文献
82.
A co‐oxidation model was constructed from available submechanisms for ammonia and ethanol oxidation. The ammonia submechanism validated for combustion at atmospheric pressure conditions was modified for the higher densities and lower temperatures (655–700°C) of supercritical water. The ethanol submechanism had previously been tested and validated at supercritical water conditions. The initial model poorly reproduced experimental ammonia conversion data and was not able to consistently match nitrous oxide production as a function of temperature over a range from 655–700°C at 246 bar. To improve model predictions, the low‐pressure NH2 + NOx submechanism was replaced with a submechanism that included the H2NNOx adduct species that are expected to be stabilized in the high‐pressure supercritical water environment. Thermochemical and kinetic parameters for the adduct species were estimated with quantum chemical calculations using Gaussian 98 with the CBS‐Q method. The explicit treatment of the H2NNOx adducts resulted in nitrous oxide yield predictions that correctly reproduced experimental trends. This work represents a vital first step in improving the understanding of ammonia oxidation in supercritical water. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 653–662, 2008 相似文献
83.
Roberto Luiz Soraggi 《Annali di Matematica Pura ed Applicata》1986,144(1):1-22
Summary
We study the bounded sets in the space of holomorphic germs defined on compact subsets of non-metrizable locally convex spaces. We relate this problem to the problem of existence of uniform Cauchy estimates for the bounded subsets. We show that the space of holomorphic germs defined on a compact subset of a reflexive dual Fréchet space is regular if the bounded subsets of the space of holomorphic germs defined at the origin have uniform Cauchy estimates. 相似文献
84.
Johanna Méndez Arias Anelize de Oliveira Moraes Luiz Felipe Amarante Modesto Aline Machado de Castro Nei Pereira Jr 《Applied biochemistry and biotechnology》2017,181(2):593-603
Poly(ethylene glycol) (PEG 4000) and bovine serum albumin (BSA) were investigated with the purpose of evaluating their influence on enzymatic hydrolysis of sugarcane bagasse. Effects of these supplements were assayed for different enzymatic cocktails (Trichoderma harzianum and Penicillium funiculosum) that acted on lignocellulosic material submitted to different pretreatment methods with varying solid (25 and 100 g/L) and protein (7.5 and 20 mg/g cellulose) loadings. The highest levels of glucose release were achieved using partially delignified cellulignin as substrate, along with the T. harzianum cocktail: increases of 14 and 18 % for 25 g/L solid loadings and of 33 and 43 % for 100 g/L solid loadings were reached for BSA and PEG supplementation, respectively. Addition of these supplements could maintain hydrolysis yield even for higher solid loadings, but for higher enzymatic cocktail protein loadings, increases in glucose release were not observed. Results indicate that synergism might occur among these additives and cellulase and xylanases. The use of these supplements, besides depending on factors such as pretreatment method of sugarcane bagasse, enzymatic cocktails composition, and solid and protein loadings, may not always lead to positive effects on the hydrolysis of lignocellulosic material, making it necessary further statistical studies, according to process conditions. 相似文献
85.
Aires da Conceição Silva Lucia C.S. Aguiar Andréa Luzia F. de Souza Luiz Fernando Brum Malta 《Tetrahedron letters》2010,51(30):3883-6491
In this work, we present ligand-free Suzuki cross-coupling reactions in PEG 300 under thermal conditions at 55 °C with good yields of conversion; better results were obtained with low reaction time. In 1 hour, 1-iodo-4-nitrobenzene and phenylboronic acid reached 98% of the yield and 9700 of TON. Better results were obtained with Pd(0) sources. The reaction system was recycled up to three times with good activity. 相似文献
86.
Filgueira Dde M Guterres LP Votto AP Vargas MA Boyle RT Trindade GS Nery LE 《Photochemistry and photobiology》2010,86(6):1278-1284
The purpose of this study was to verify the occurrence of pigment dispersion in retinal pigment cells exposed to UVA and UVB radiation, and to investigate the possible participation of a nitric oxide (NO) pathway. Retinal pigment cells from Neohelice granulata were obtained by cellular dissociation. Cells were analyzed for 30 min in the dark (control) and then exposed to 1.1 and 3.3 J cm−2 UVA, 0.07 and 0.9 J cm−2 UVB, 20 n m β-PDH (pigment dispersing hormone) or 10 μ m SIN-1 (NO donor). Histological analyses were performed to verify the UV effect in vivo . Cultured cells were exposed to 250 μ m L-NAME (NO synthase blocker) and afterwards were treated with UVA, UVB or β-PDH. The retinal cells in culture displayed significant pigment dispersion in response to UVA, UVB and β-PDH. The same responses to UVA and UVB were observed in vivo . SIN-1 did not induce pigment dispersion in the cell cultures. l-NAME significantly decreased the pigment dispersion induced by UVA and UVB but not by β-PDH. All retinal cells showed an immunopositive reaction against neuronal nitric oxide synthases. Therefore, UVA and UVB radiation are capable of inducing pigment dispersion in retinal pigment cells of Neohelice granulata and this dispersion may be nitric oxide synthase dependent. 相似文献
87.
Mario Ribeiro de Melo-Júnior Jorge Luiz Silva Araújo-Filho Consuelo Antunes Barreto Lins Nicodemos Teles de Pontes-Filho Luiz Bezerra de CarvalhoJr 《Applied biochemistry and biotechnology》2010,160(8):2198-2207
This work aimed to immobilize the antibody anti-galectin-3 onto polysiloxane–polyvinyl alcohol (POS-PVA) support, to evaluate
its capacity to capture the serum antigen galectin-3 and to quantify by ELISA the antigen levels in sera from patients with
prostatic adenocarcinoma (PA) and benign prostatic hyperplasia (BPH) and healthy individuals. Also, for comparative effect,
the galectin-3 expression in the prostate tissue through immunohistochemistry was evaluated. The optical density (galectin-3
level) values established for the sera from PA and BPH patients were lower compared with those found for the healthy individuals.
Galectin-3 immunohistochemically showed a significant increase and reduction of the cytoplasmatic protein expression in BPH
and PA, respectively, compared with the normal prostate. These results showed that POS-PVA disks could be used as solid phase
to immobilize serum galectins and in immunoassays procedures for the correspondent IgG anti-galectins detection in human sera. 相似文献
88.
Puebla P Oshima-Franco Y Franco LM Santos MG Silva RV Rubem-Mauro L Feliciano AS 《Molecules (Basel, Switzerland)》2010,15(11):8193-8204
The effect of four sub-extracts prepared from the lyophilized hydroalcoholic bark of Dipteryx alata (Leguminosae-Papilionoideae) dissolved in a methanol-water (80:20) mixture through a liquid-liquid partition procedure has been investigated against the neuromuscular blockade of the venom of the snake Bothrops jararacussu. The active CH?Cl? sub-extract has been extensively analyzed for its chemical constituents, resulting in the isolation of four lupane-type triterpenoids: lupeol, lupenone, 28-hydroxylup-20(29)-en-3-one, betulin, nine isoflavonoids: 8-O-methylretusin, 7-hydroxy-5,6,4'-trimethoxyisoflavone, afrormosin, 7-hydroxy-8,3',4'-trimethoxyisoflavone, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, odoratin, 7,8,3'-trihydroxy-4'-methoxyisoflavone, 7,8,3'-trihydroxy-6,4'-dimethoxyisoflavone, dipteryxin, one chalcone: isoliquiritigenin, one aurone: sulfuretin and three phenolic compounds: vanillic acid, vanillin, and protocatechuic acid. Their chemical structures were elucidated on the basis of spectroscopic analysis, including HRMS, 1D- and 2D-NMR techniques. 相似文献
89.
Mariana R. Almeida Rafael S. Alves Laura B. L. R. Nascimbem Rodrigo Stephani Ronei J. Poppi Luiz Fernando C. de Oliveira 《Analytical and bioanalytical chemistry》2010,397(7):2693-2701
Fourier transform Raman spectroscopy and chemometric tools have been used for exploratory analysis of pure corn and cassava starch samples and mixtures of both starches, as well as for the quantification of amylose content in corn and cassava starch samples. The exploratory analysis using principal component analysis shows that two natural groups of similar samples can be obtained, according to the amylose content, and consequently the botanical origins. The Raman band at 480 cm?1, assigned to the ring vibration of starches, has the major contribution to the separation of the corn and cassava starch samples. This region was used as a marker to identify the presence of starch in different samples, as well as to characterize amylose and amylopectin. Two calibration models were developed based on partial least squares regression involving pure corn and cassava, and a third model with both starch samples was also built; the results were compared with the results of the standard colorimetric method. The samples were separated into two groups of calibration and validation by employing the Kennard-Stone algorithm and the optimum number of latent variables was chosen by the root mean square error of cross-validation obtained from the calibration set by internal validation (leave one out). The performance of each model was evaluated by the root mean square errors of calibration and prediction, and the results obtained indicate that Fourier transform Raman spectroscopy can be used for rapid determination of apparent amylose in starch samples with prediction errors similar to those of the standard method. Figure
Raman spectroscopy has been successfully applied to the determination of the amylose content in cassava and corn starches by means of multivariate calibration analysis. 相似文献
90.
André Luiz Tessaro Vagner Roberto Batistela Augusto César Gracetto Hueder Paulo Moisés de Oliveira Rosana Lazara Sernaglia Vagner Roberto de Souza Wilker Caetano Noboru Hioka 《Journal of Physical Organic Chemistry》2011,24(2):155-161
Benzoporphyrin monoacid derivatives, here named B3A and B3B, are promising new drugs for photodynamic therapy. Although both isomers show interesting characteristics as photosensitizing compounds, they have some distinct physicochemical properties such as the tendency to self‐aggregate in water‐rich media. Because pH drives the presence of each species, the pKa of these compounds assumes strategic importance. However, traditional micro‐titration methods and UV–Vis absorption techniques fail to give reliable pKa values due to the characteristics of this highly complex system, such as the precipitation of hydrophobic species, close pKa values, and high absorption band superposition. In the present work, chemometric tools are employed to evaluate pKa, and the kinetic tendency of monomers to undergo self‐aggregation is investigated. In solvent mixtures at low water percentage in ethanol, both B3A and B3B are stabilized in a monomeric state. However, in mixtures with a high water content, self‐aggregation takes place, mainly under a mild pH acid condition (3 < pH < 6), in which the prevalent protolytic species of both isomers is the neutral charged form, compounds with carboxylic and porphyrin free‐base groups. It is demonstrated that both isomers can undergo aggregation following a self‐catalytic mechanism, which is 2000 times slower to B3A than B3B. For B3A, the aggregation is manifested by a decrease in the monomer band with the aggregation band probably superposed to that of the monomer. For B3B, together with the decrease in the monomer band, a new band related to self‐aggregates is observed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献