Cellular decomposition of quaternionic spherical space forms

We obtain an explicit cellular decomposition of the quaternionic spherical space forms, manifolds of positive constant curvature that are factors of an odd sphere by a free orthogonal action of a generalized quaternionic group. The cellular structure gives and explicit description of the associated cellular chain complex of modules over the integral group ring of the fundamental group. As an application we compute the Whitehead torsion of these spaces for any representation of the fundamental group. © 2012 Springer Science+Business Media B.V.

Kinetic parameters for thermal decomposition of supramolecular polymers derived from diclofenac-meglumine supramolecular adducts

Meglumine is an aminocarbohydrate able to form supramolecular adducts with organic acids. The recognition is based on hydrogen bonds and the structures resulting from the complexation have high solubility in water. This property has been exploited by the pharmaceutical industry in the improvement of existing drugs, and the successful example of this approach involves the poorly soluble non-steroidal anti-inflammatory drugs (NSAIDs). Investigation of the thermal behavior of adduct obtained from meglumine and the NSAID diclofenac revealed that a polymer-like material is formed from the self-assembly of diclofenac-meglumine adducts in the melt. This polymer showed a high molecular weight around 2.0×105kDa. The kinetic parameters for the thermal decomposition step of the polymer were determined by the Capela-Ribeiro non-linear isoconversional method. From data for the TG curves in nitrogen atmosphere and heating rates of 5, 10, 15 and 20°Cmin-1, the Eα and Bα terms could be determined, and consequently the pre-exponential factor, Aα, as well as the kinetic model, g(α). © 2012 Elsevier B.V.

Use of algorithms for semi-automatic quantification of pulmonary fibrosis and emphysema

Obtaining a semi-automatic quantification of pathologies found in the lung, through images of high resolution computed tomography (HRCT), is of great importance to aid in medical diagnosis. Paraccocidioidomycosis (PCM) is a systemic disease that affects the lung and even after effective treatment leaves sequels such as pulmonary fibrosis and emphysema. It is very important to the area of tropical diseases that the lung injury be quantified more accurately. In this stud, we propose the development of algorithms in computational environment Matlab® able to objectively quantify lung diseases such as fibrosis and emphysema. The program consists in selecting the region of interest (ROI), and through the use of density masks and filters, obtaining the lesion area quantification in relation to the healthy area of the lung. The proposed method was tested on 15 exams of HRCT of patients with confirmed PCM. To prove the validity and effectiveness of the method, we used a virtual phantom, also developed in this research. © 2013 Springer-Verlag.

Decomposition dynamics of soybean residues in two soils of different fertility

The study objective was to evaluate the influence of the addition of soybeans residues on the chemical properties of Eutrudox and Hapludox soils. Soybean leaves and stems were incubated for 0-200 days. The statistical model used was a 5×4 factorial (plantxincubation period) with three replications. Soils without addition of plants were used as controls. Total Organic Carbon (TOC), Soluble Carbon (SC), Total Carbohydrates (TC), Humic Acid (HA), Fulvic Acid (FA) and Humification Rate (HR) were determined. Higher values of chemical attributes (TOC, SC and TC) were found in the Eutrudox soil than in the Hapludox soil and these values increased significantly (p<0.05) after 50 days of incubation in relation to the initial period. The TOC, SC and TC increased in soils amended with soybean plants when compared to controls without plants. HA and FA contents and HR were not affected by the addition of soybean residues. Maximum HA contents were found after 100 days and maximum FA contents and HR were found after 200 days incubation in both soils. It can be concluded that the addition of soybean residues increased the soil chemical properties when compared to the controls. © 2013 Academic Journals Inc.

An approach to implement data fusion techniques in wireless sensor networks using genetic machine learning algorithms

Wireless Sensor Networks (WSNs) can be used to monitor hazardous and inaccessible areas. In these situations, the power supply (e.g. battery) of each node cannot be easily replaced. One solution to deal with the limited capacity of current power supplies is to deploy a large number of sensor nodes, since the lifetime and dependability of the network will increase through cooperation among nodes. Applications on WSN may also have other concerns, such as meeting temporal deadlines on message transmissions and maximizing the quality of information. Data fusion is a well-known technique that can be useful for the enhancement of data quality and for the maximization of WSN lifetime. In this paper, we propose an approach that allows the implementation of parallel data fusion techniques in IEEE 802.15.4 networks. One of the main advantages of the proposed approach is that it enables a trade-off between different user-defined metrics through the use of a genetic machine learning algorithm. Simulations and field experiments performed in different communication scenarios highlight significant improvements when compared with, for instance, the Gur Game approach or the implementation of conventional periodic communication techniques over IEEE 802.15.4 networks. © 2013 Elsevier B.V. All rights reserved.

Kinetic parameters for thermal decomposition of hydrazine

The propulsion of most of the operating satellites comprises monopropellant (hydrazine - N2H4) or bipropellant (monometilydrazine - MMH and nitrogen tetroxide) chemical systems. When some sample of the propellant tested fails, the entire sample lot shall be rejected, and this action has turned into a health problem due to the high toxicity of N2H 4. Thus, it is interesting to know hydrazine thermal behavior in several storage conditions. The kinetic parameters for thermal decomposition of hydrazine in oxygen and nitrogen atmospheres were determined by Capela-Ribeiro nonlinear isoconversional method. From TG data at heating rates of 5, 10, and 20 C min-1, kinetic parameters could be determined in nitrogen (E = 47.3 ± 3.1 kJ mol-1, lnA = 14.2 ± 0.9 and T b = 69 C) and oxygen (E = 64.9 ± 8.6 kJ mol-1, lnA = 20.7 ± 3.1 and T b = 75 C) atmospheres. It was not possible to identify a specific kinetic model for hydrazine thermal decomposition due to high heterogeneity in reaction; however, experimental f(α)g(α) master-plot curves were closed to F 1/3 model. © 2013 Akadémiai Kiadó, Budapest, Hungary.

Análise e implementação de um algoritmo de busca dispersa para o planejamento da expansão de sistemas de transmissão

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Novas aplicações de metaheurísticas na solução do problema de planejamento da expansão do sistema de transmissão de energia elétrica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sobre um método assemelhado ao de Francis para a determinação de autovalores de matrizes

Pós-graduação em Matemática - IBILCE

Identificação dos parâmetros modais utilizando apenas as respostas da estrutura: identificação no domínio do tempo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estratégia de decomposição aplicada ao problema de planejamento da expansão de sistemas de distribuição

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

Leaf-litter decomposition of the mangrove species Avicennia schaueriana, Laguncularia racemosa and Rhizophora mangle

This study evaluated the decomposition process of leaf litter from the main Brazilian mangrove species Avicennia schaueriana, Laguncularia racemosa and Rhizophora mangle. Senescent leaves were collected, dried and placed in nylon bags with different mesh sizes (fine: 2x2mm and coarse: 8x8mm). The bags were distributed over the sediment, and replicates of each species and mesh size were collected periodically over 4months. In the laboratory, the dry weight of the samples was measured, and the decomposition coefficient (k) for each species and mesh size was obtained over time. All species showed a rapid decomposition rate at the beginning of the experiment, followed by a slower but steady rate of decomposition over time. The rate of leaf litter decomposition was highest in A. schaueriana, intermediate in L. racemosa and lowest in R. mangle. The difference was mainly linked to the activity and abundance of detritivores, together with the different litter quality of the species, which determined their palatability and probably influenced the decomposition process.

Study of some volatile compounds evolved from the thermal decomposition of atenolol

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

Singular Value Decomposition and Ligand Binding Analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of Decomposition Kinetics of Poly (Ether-Ether-Ketone) by Thermogravimetric Analysis

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