As técnicas NASVD e MNF e sua aplicação na redução de ruídos em dados gamaespectrométricos

A desintegração radioativa é um processo aleatório e a estimativa de todas as medidas associadas é governada por leis estatísticas. Os perfis de taxas de contagem são sempre "ruidosos" quando utilizados períodos curtos como um segundo para cada medida. Os filtros utilizados e posteriormente as correções feitas no processamento atual de dados gamaespectrométricos não são suficientes para remover ou diminuir, consideravelmente, o ruído oriundo do espectro. Dois métodos estatísticos que atuam diretamente nos dados coletados, isto é, nos espectros, vêm sendo sugeridos na literatura para remover e minimizar estes ruídos remanescentes o Noise-Adjusted Singular Value Decomposition - NASVD e Maximum Noise Fraction - MNF. Estes métodos produzem uma redução no ruído de forma significativa. Neste trabalho eles foram implementados dentro do ambiente de processamento do software Oasis Montaj e aplicados na área compreendida pelos blocos I e II do levantamento aerogeofísico que recobre a porção oeste da Província Mineral do Tapajós, entre os Estados do Pará e Amazonas. Os dados filtrados e não-filtrados com as técnicas de NASVD e MNF foram processados com os parâmetros e constantes fornecidos pela empresa Lasa Engenharia e Prospecções S.A., sendo estes comparados. Os resultados da comparação entre perfis e mapas apresentaram-se de forma promissora, pois houve um ganho na resolução dos produtos.

Chaotic Patterns in Aeroelastic Signals

This work presents the analysis of nonlinear aeroelastic time series from wing vibrations due to airflow separation during wind tunnel experiments. Surrogate data method is used to justify the application of nonlinear time series analysis to the aeroelastic system, after rejecting the chance for nonstationarity. The singular value decomposition (SVD) approach is used to reconstruct the state space, reducing noise from the aeroelastic time series. Direct analysis of reconstructed trajectories in the state space and the determination of Poincare sections have been employed to investigate complex dynamics and chaotic patterns. With the reconstructed state spaces, qualitative analyses may be done, and the attractors evolutions with parametric variation are presented. Overall results reveal complex system dynamics associated with highly separated flow effects together with nonlinear coupling between aeroelastic modes. Bifurcations to the nonlinear aeroelastic system are observed for two investigations, that is, considering oscillations-induced aeroelastic evolutions with varying freestream speed, and aeroelastic evolutions at constant freestream speed and varying oscillations. Finally, Lyapunov exponent calculation is proceeded in order to infer on chaotic behavior. Poincare mappings also suggest bifurcations and chaos, reinforced by the attainment of maximum positive Lyapunov exponents. Copyright (C) 2009 F. D. Marques and R. M. G. Vasconcellos.

Topology optimization for designing strain-gauge load cells

Load cells are used extensively in engineering fields. This paper describes a novel structural optimization method for single- and multi-axis load cell structures. First, we briefly explain the topology optimization method that uses the solid isotropic material with penalization (SIMP) method. Next, we clarify the mechanical requirements and design specifications of the single- and multi-axis load cell structures, which are formulated as an objective function. In the case of multi-axis load cell structures, a methodology based on singular value decomposition is used. The sensitivities of the objective function with respect to the design variables are then formulated. On the basis of these formulations, an optimization algorithm is constructed using finite element methods and the method of moving asymptotes (MMA). Finally, we examine the characteristics of the optimization formulations and the resultant optimal configurations. We confirm the usefulness of our proposed methodology for the optimization of single- and multi-axis load cell structures.

Combining Legendre's Polynomials and Genetic Algorithm in the Solution of Nonlinear Initial-Value Problems

This work develops a method for solving ordinary differential equations, that is, initial-value problems, with solutions approximated by using Legendre's polynomials. An iterative procedure for the adjustment of the polynomial coefficients is developed, based on the genetic algorithm. This procedure is applied to several examples providing comparisons between its results and the best polynomial fitting when numerical solutions by the traditional Runge-Kutta or Adams methods are available. The resulting algorithm provides reliable solutions even if the numerical solutions are not available, that is, when the mass matrix is singular or the equation produces unstable running processes.

Singular Perturbation for the Discounted Continuous Control of Piecewise Deterministic Markov Processes

This paper deals with the expected discounted continuous control of piecewise deterministic Markov processes (PDMP`s) using a singular perturbation approach for dealing with rapidly oscillating parameters. The state space of the PDMP is written as the product of a finite set and a subset of the Euclidean space a""e (n) . The discrete part of the state, called the regime, characterizes the mode of operation of the physical system under consideration, and is supposed to have a fast (associated to a small parameter epsilon > 0) and a slow behavior. By using a similar approach as developed in Yin and Zhang (Continuous-Time Markov Chains and Applications: A Singular Perturbation Approach, Applications of Mathematics, vol. 37, Springer, New York, 1998, Chaps. 1 and 3) the idea in this paper is to reduce the number of regimes by considering an averaged model in which the regimes within the same class are aggregated through the quasi-stationary distribution so that the different states in this class are replaced by a single one. The main goal is to show that the value function of the control problem for the system driven by the perturbed Markov chain converges to the value function of this limit control problem as epsilon goes to zero. This convergence is obtained by, roughly speaking, showing that the infimum and supremum limits of the value functions satisfy two optimality inequalities as epsilon goes to zero. This enables us to show the result by invoking a uniqueness argument, without needing any kind of Lipschitz continuity condition.

Adding value to the meat of spent laying hens manufacturing sausages with a healthy appeal

The aim of this study was to evaluate the viability of the use of spent laying hens' meat in the manufacturing of mortadella-type sausages with healthy appeal by using vegetable oil instead of animal fat. 120 Hy-line® layer hens were distributed in a completely randomized design into two treatments of six replicates with ten birds each. The treatments were birds from light Hy-line® W36 and semi-heavy Hy-line® Brown lines. Cold carcass, wing, breast and leg fillets yields were determined. Dry matter, protein, and lipid contents were determined in breast and leg fillets. The breast and legg fillets of three replicates per treatment were used to manufacture mortadella. After processing, sausages were evaluated for proximal composition, objective color, microbiological parameters, fatty acid profile and sensory acceptance. The meat of light and semi-heavy spent hens presented good yield and composition, allowing it to be used as raw material for the manufacture of processed products. Mortadellas were safe from microbiological point of view, and those made with semi-heavy hens fillets were redder and better accepted by consumers. Values for all sensory attributes were evaluated over score 5 (neither liked nor disliked). Both products presented high polyunsaturated fatty acid contents and good polyunsaturated to saturated fatty acid ratio. The excellent potential for the use of meat from spent layer hens of both varieties in the manufacturing of healthier mortadella-type sausage was demonstrated.

E o Iphan retirou o véu da noiva e disse sim: ecletismo e modernismo no edifício Luciano Costa

São raros os momentos, na história das políticas de preservação do patrimônio no Brasil, em que se vê a dimensão de um conflito - gerado pela atribuição de valores a um bem cultural - alcançar repercussão significativa, mobilizando diversos agentes. O caso do edifício Luciano Costa, no Recife, é um exemplo dessa natureza. Neste artigo, procuramos apresentar -a partir da interpretação de uma trama complexa de discursos e ações - a polêmica preservacionista em torno desse edifício, um exemplar arquitetônico singular, por ter simultaneamente duas fachadas, uma eclética e uma modernista. Em grande parte inéditos, os documentos técnico-administrativos da 5ª Superintendência Regional e do Departamento de Documentação do Iphan, assim como aqueles da fundação do Patrimônio Histórico e Artístico de Pernambuco (fundarpe), da Diretoria de Projetos Especiais da Empresa de Urbanização do Recife (URb-Recife) e do Ministério Público de Pernambuco foram as fontes primárias privilegiadas.

Nutritive value and physical characteristics of Xaraes palisadegrass as affected by grazing strategy

The aim of this study was to ascertain whether the defoliation frequency based on a fixed rest period would generate variable sward structural and physiological conditions at each subsequent grazing event. The relative importance of the physiological age was established in comparison with the chronological age in the determination of the forage nutritive value of Xaraes palisadegrass [Brachiaria brizantha (Hochst ex A. RICH.) STAPF. cv. Xaraes]. Two grazing frequencies were defined by light interception (LI) at initiation of grazing (95% LI - ""target grazing"" [TG] or 100% LI - ""delayed grazing"" [DG]) and one based on chronological time, grazing every 28 days (28-d). Forage produced under the TG schedule was mostly leaves (93%) with a higher concentration of crude protein (CP; 138 g/kg in the whole forage), a lower concentrations of neutral detergent fibre (NDF) in the stems (740 g/kg), and higher in vitro dry matter digestibility (IVDMD) of the leaves (690 g/kg), compared to the other treatments. Lower grazing frequency strategies (DG and 28-d) resulted in forage with higher proportions of stems (10 and 9%, respectively). Strategies based on light interception did not produce pre-graze forage with a uniform nutritive value, as the indicators varied across grazing cycles. The treatment based on fixed days of rest did not result in uniformity.

Prognostic value of TP53 Pro47Ser and Arg72Pro single nucleotide polymorphisms and the susceptibility to gliomas in individuals from Southeast Brazil

The TP53 tumor suppressor gene codifies a protein responsible for preventing cells with genetic damage from growing and dividing by blocking cell growth or apoptosis pathways. A common single nucleotide polymorphism (SNP) in TP53 codon 72 (Arg72Pro) induces a 15-fold decrease of apoptosis-inducing ability and has been associated with susceptibility to human cancers. Recently, another TP53 SNP at codon 47 (Pro47Ser) was reported to have a low apoptosis-inducing ability; however, there are no association studies between this SNP and cancer. Aiming to study the role of TP53 Pro47Ser and Arg72Pro on glioma susceptibility and oncologic prognosis of patients, we investigated the genotype distribution of these SNPs in 94 gliomas (81 astrocytomas, 8 ependymomas and 5 oligodendrogliomas) and in 100 healthy subjects by the polymerase chain reaction-restriction fragment length polymorphism approach. Chi-square and Fisher exact test comparisons for genotype distributions and allele frequencies did not reveal any significant difference between patients and control groups. Overall and disease-free survivals were calculated by the Kaplan-Meier method, and the log-rank test was used for comparisons, but no significant statistical difference was observed between the two groups. Our data suggest that TP53 Pro47Ser and Arg72Pro SNPs are not involved either in susceptibility to developing gliomas or in patient survival, at least in the Brazilian population.

Multi-trait and random regression mature weight heritability and breeding value estimates in Nelore cattle

Mature weight breeding values were estimated using a multi-trait animal model (MM) and a random regression animal model (RRM). Data consisted of 82 064 weight records from 8 145 animals, recorded from birth to eight years of age. Weights at standard ages were considered in the MM. All models included contemporary groups as fixed effects, and age of dam (linear and quadratic effects) and animal age as covariates. In the RRM, mean trends were modelled through a cubic regression on orthogonal polynomials of animal age and genetic maternal and direct and maternal permanent environmental effects were also included as random. Legendre polynomials of orders 4, 3, 6 and 3 were used for animal and maternal genetic and permanent environmental effects, respectively, considering five classes of residual variances. Mature weight (five years) direct heritability estimates were 0.35 (MM) and 0.38 (RRM). Rank correlation between sires' breeding values estimated by MM and RRM was 0.82. However, selecting the top 2% (12) or 10% (62) of the young sires based on the MM predicted breeding values, respectively 71% and 80% of the same sires would be selected if RRM estimates were used instead. The RRM modelled the changes in the (co) variances with age adequately and larger breeding value accuracies can be expected using this model.

Determination of the minimum value of the safety factor from geodesic Alfven eigenmodes in Joint European Torus

An analysis of the experimental conditions under which low-frequency (70-150 kHz) Alfven eigertmodes (AE) are excited during the monster sawtooth in Joint European Torus [F Romanelli et al, Proceedings of the 22nd IAEA Fusion Energy Conference, Geneva, Switzerland, 2008] is presented for the specific case of a discharge with ion cyclotron heating (5 MW) Using a simplified AE model for modes excited at the Alfven wave continuum maximum with geodesic corrections taken into account, the temporal evolution of the value of the safety factor q(0) at the magnetic axis is determined We describe a new scheme to determine the time variation of q(0) that works under conditions in which other standard diagnostics, such as the motional Stark effect do not give reliable results such as during a monster sawtooth [doi 10 1063/1 3494212]

f t value of the 0(+)-> 0(+) beta(+) decay of (32)Ar: A measurement of isospin symmetry breaking in a superallowed decay

We determined the absolute branch of the T=2 superallowed decay of (32)Ar by detecting the beta(+)-delayed protons and gamma decays of the daughter state. We obtain b(SA)(beta)=(22.71 +/- 0.16)%, which represents the first determination of a proton branch to better than 1%. Using this branch along with the previously determined (32)Ar half-life and energy release, we determined ft=(1552 +/- 12) s for the superallowed decay. This ft value, together with the corrected Ft value extracted from previously known T=1 superallowed decays, yields a measurement of the isospin symmetry breaking correction in (32)Ar decay delta(exp)(C)=(2.1 +/- 0.8)%. This can be compared to a theoretical calculation delta(C)=(2.0 +/- 0.4)%. As by-products of this work, we determined the gamma and proton branches for the decay of the lowest T=2 state of (32)Cl, made a precise determination of the total proton branch and relative intensities of proton groups that leave (31)S in its first excited state and deduced an improved value for the (32)Cl mass.

Equifocality of a singular Riemannian foliation

A singular foliation on a complete Riemannian manifold M is said to be Riemannian if each geodesic that is perpendicular to a leaf at one point remains perpendicular to every leaf it meets. We prove that the regular leaves are equifocal, i.e., the end point map of a normal foliated vector field has constant rank. This implies that we can reconstruct the singular foliation by taking all parallel submanifolds of a regular leaf with trivial holonomy. In addition, the end point map of a normal foliated vector field on a leaf with trivial holonomy is a covering map. These results generalize previous results of the authors on singular Riemannian foliations with sections.

Nanogravimetric and voltammetric studies of a Pt-Rh alloy surface and its behavior for methanol oxidation

This paper describes the preparation of a Pt-Rh alloy surface electrodeposited on Pt electrodes and its electrocatalytic characterization for methanol oxidation. The X-ray photoelectronic spectroscopy ( XPS) results demonstrate that the surface composition is approximately 24 at-% Rh and 76 % Pt. The cyclic voltammetry (CV) and electrochemical quartz crystal (EQCN) results for the alloy were associated, for platinum, to the well known profile in acidic medium. For Rh, on the alloy, the generation of rhodium hydroxide species (Rh(OH)(3) and RhO(OH)(3)) was measured. During the successive oxidation-reduction cycles the mass returns to its original value, indicating the reversibility of the processes. It was not observed rhodium dissolution during the cycling. The 76/24 at % Pt-Rh alloy presented singular electrocatalytic activity for methanol electrooxidation, which started at more negative potentials compared to pure Pt (70 mV). During the sweep towards more negative potentials, there is only weak CO re-adsorption on both Rh and Pt-Rh alloy surfaces, which can be explained by considering the interaction energy between Rh and CO.

BEM formulation for von Karman plates

This work deals with nonlinear geometric plates in the context of von Karman`s theory. The formulation is written such that only the boundary in-plane displacement and deflection integral equations for boundary collocations are required. At internal points, only out-of-plane rotation, curvature and in-plane internal force representations are used. Thus, only integral representations of these values are derived. The nonlinear system of equations is derived by approximating all densities in the domain integrals as single values, which therefore reduces the computational effort needed to evaluate the domain value influences. Hyper-singular equations are avoided by approximating the domain values using only internal nodes. The solution is obtained using a Newton scheme for which a consistent tangent operator was derived. (C) 2009 Elsevier Ltd. All rights reserved.