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131.
K. Donadel C.R. Rambo W.S. Chacon M.D.M. Innocentini R.C. Catapan D. Muller A.A.M. Oliveira A.P.N. Oliveira 《Ceramics International》2012
In this work catalytic fibrous filters were produced through two distinct processing routes from natural amorphous silica fibers (NASF) and Ni(NO3)2 solution (wet route) and NiO (dry route) as catalyst precursors. The Ni–SiO2 fibers were characterized for X-ray powder diffraction, scanning electron microscope, particle size distribution, specific surface area, nickel contents, porosity, tortuosity, permeability, compressive strength, degree of dispersion, filtration and gas conversion efficiency. Morphological characterization revealed that Ni from wet route was distributed over the silica fibers with significantly lower particle size than the Ni produced through the dry route. Both methods led to a homogeneous distribution of Ni. The catalytic fibrous filter obtained from the dry route showed higher conversion efficiency for both propylene and propane, especially at high temperatures, due to the higher degree of dispersion of Ni particles over the NASF surfaces. 相似文献
132.
Matias Urbieta Ana Oliveira João Araújo Armanda Rodrigues Ana Moreira Sílvia Gordillo Gustavo Rossi 《Innovations in Systems and Software Engineering》2014,10(1):59-75
Spatial concerns of Web geographical information systems (Web-GIS) are inherently crosscutting and volatile: crosscutting because they affect multiple functionalities of Web-GIS systems, and volatile because their status may change often. If these concerns are not modularized properly, the quality of Web-GIS services, particularly with regard to adaptation and evolution, can be severely compromised. This paper uses aspect-orientation to model crosscutting and volatile spatial concerns. By modeling both types of concerns, crosscutting and volatile, as candidate aspects, one can use dynamic weaving to add or remove them from a system at runtime. The aspect-oriented approach proposed starts with the identification and specification of crosscutting concerns and follows by composing these using modeling aspects using a transformation approach, an aspect-oriented modeling technique. The conflicts that can emerge due to the composition order are also taken into consideration. Finally, this paper proposes a set of reusable GIS crosscutting concerns, documenting them in a concern catalogue. 相似文献
133.
R. Machado e Silva C. Esperança R. Marroquim A. A. F. Oliveira 《Computer Graphics Forum》2014,33(1):178-189
The hidden point removal (HPR) operator introduced by Katz et al. [KTB07] provides an elegant solution for the problem of estimating the visibility of points in point samplings of surfaces. Since the method requires computing the three‐dimensional convex hull of a set with the same cardinality as the original cloud, the method has been largely viewed as impractical for real‐time rendering of medium to large clouds. In this paper we examine how the HPR operator can be used more efficiently by combining several image space techniques, including an approximate convex hull algorithm, cloud sampling, and GPU programming. Experiments show that this combination permits faster renderings without overly compromising the accuracy. 相似文献
134.
Nair do Amaral Sampaio Neta José Cleiton Sousa dos Santos Soraya de Oliveira Sancho Sueli Rodrigues Luciana Rocha Barros Gonçalves Ligia R. Rodrigues José A. Teixeira 《Food Hydrocolloids》2012
Sugar esters are compounds with surfactant properties (biosurfactants), i.e., capable of reducing the surface tension and promote the emulsification of immiscible liquids. On the other hand, as with all emulsions, coconut milk is not physically stable and is prone to phase separation. Therefore, the aim of this work was to evaluate the synthesis of fructose, sucrose and lactose esters from the corresponding sugars using Candida antarctica type B lipase immobilized in two different supports, namely acrylic resin and chitosan, and evaluate its application in the stabilization of coconut milk emulsions. The enzyme immobilized on chitosan showed the highest yield of lactose ester production (84.1%). Additionally, the production of fructose ester was found to be higher for the enzyme immobilized on the acrylic resin support (74.3%) as compared with the one immobilized on chitosan (70.1%). The same trend was observed for the sucrose ester, although with lower percentage yields. Sugar esters were then added to samples of fresh coconut milk and characterized according to their surface tension, emulsification index and particle size distribution. Although the microscopic analysis showed similar results for all sugar esters, results indicated lactose ester as the best biosurfactant, with a surface tension of 38.0 N/m and an emulsification index of 54.1%, when used in a ratio of 1:10 (biosurfactant:coconut milk, v/v) for 48 h experiments. 相似文献
135.
Application and bioactive properties of CaTI,a trypsin inhibitor from Capsicum annuum seeds: membrane permeabilization,oxidative stress and intracellular target in phytopathogenic fungi cells 下载免费PDF全文
136.
This paper investigates the well-known separation properties that hold in the design of unconstrained output feedback controllers and tries to generalize them to cope with the design of structurally constrained decentralized controls. This problem, which until now has been open, presents additional constraints which destroy the useful properties that lead to separation. Necessary and sufficient conditions for decentralized stability and H2 norm minimization are given, providing a framework in which a suitable ad hoc separation procedure is developed. A numerical algorithm based on crossdecomposition is presented and applied in two situations: first, when separation fails to provide a feasible solution; and then, to improve the obtained controller. An example and a comprehensive benchmark illustrate and validate the method. 相似文献
137.
138.
Ângelo Márcio Oliveira Sant’Anna Carla Schwengber ten Caten 《Expert systems with applications》2012,39(11):10236-10243
p-Charts and np-Charts are commonly used in monitoring variables of the fraction type and these charts assume that the monitored variables are binomially distributed. In this paper we propose a new control chart called Beta Charts, for monitoring fraction data (p). The Beta Chart presents the control limits based on the Beta probability distribution. It was applied for monitoring the variables in three real studies, and it was compared to the control limits with three schemes. The comparative analysis showed that: (i) Beta approximation to the Binomial distribution was more appropriate with values confined in the [0, 1]-interval; and (ii) the charts proposed were more sensitive to the average run length (ARL), in both in-control and out-of-control processes monitoring. The Beta Charts outperform the control charts analyzed for monitoring fraction data. 相似文献
139.
Omar Arafat Kdudsi Khalil Olga Maria Mascarenhas de Faria Oliveira José Carlos Rebuglio Vellosa Andreza Urba de Quadros Loriangela Marceli Dalposso Thaysa Ksiaskiewcz Karam Rubiana Mara Mainardes Najeh Maissar Khalil 《Food chemistry》2012
The objective of this study was to evaluate the antifungal and antioxidant activities of curcumin, ascorbic acid and the mixture of these two compounds. For the antifungal assay, the minimum inhibitory concentrations (MIC) were determined using Candida strains (ATCC and clinical isolates). Curcumin alone inhibited growth of Candida albicans yeast cells, whereas ascorbic acid did not present effects. However, when the mixture of ascorbic acid and curcumin was assayed to determine the association of the two compounds, the curcumin MIC decreased 5- to 10-fold. In the antioxidant assays, the sum of the alone activities of curcumin and ascorbic acid were lower than the activity of the two-compound mixture. This study highlights the importance of the association between two common antioxidants in foods, to improve the antifungal and antioxidant activities of curcumin (in vitro), and can be applied to Candida spp. infection and diseases associated with oxidative stress. 相似文献
140.
Fernando Gomes de Souza Junior José Carlos Pinto Flávia Alves Garcia Geiza Esperandio de Oliveira Maria Inês Bruno Tavares Andréa Maria da Silva Emiliane Daher Pereira 《Polymer Engineering and Science》2014,54(12):2887-2895
This article studies the modification of coconut fibers with polyaniline (PAni) with help of statistical experimental design techniques. The main factors studied here were the techniques used for particle dispersion (sonication vs. magnetic stirring) and the type of initiator (ammonium persulfate, APS, vs. ammonium cerium sulfate dihydrate, Ce(IV)). The obtained materials were characterized through low field nuclear magnetic resonance, small‐and wide‐angle X‐ray scattering, scanning electron microscopy, fourier transform infrared spectroscopy, and ultraviolet–visible spectroscopy. Additionally, the electrical resistivities and respective sensitivities to variations of the applied pressure were evaluated for all obtained samples, with help of standard volume resistivity measurements and electro‐mechanical tests. The materials prepared through magnetic stirring with APS presented the best electrical and electromechanical properties, although materials prepared through sonication with Ce(IV) also presented good electrical and electromechanical properties and could be prepared much faster. As a consequence, modification of coconut fibers with PAni, using sonication as the particle dispersion technique and Ce(IV) as initiator, constitutes a very promising procedure for manufacture of pressure‐sensitive devices. POLYM. ENG. SCI., 54:2887–2895, 2014. © 2014 Society of Plastics Engineers 相似文献