910 resultados para Multiple reflection method


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The determination of the reflection coefficient of shear waves reflected from a solid-liquid interface is an important method in order to study the viscoelastic properties of liquids at high frequency. The reflection coefficient is a complex number. While the magnitude measurement is relatively easy and precise, the phase measurement is very difficult due to its strong temperature dependence. For that reason, most authors choose a simplified method in order to obtain the viscoelastic properties of liquids from the measured coefficient. In this simplified method, inconsistent viscosity results are obtained because pure viscous behavior is assumed and the phase is not measured. This work deals with an effort to improve the experimental technique required to measure both the magnitude and phase of the reflection coefficient and it intends to report realistic values for oils in a wide range of viscosity (0.092 - 6.7 Pa.s). Moreover, a device calibration process is investigated in order to monitor the dynamic viscosity of the liquid.

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In this work the interaction of the pesticide carbaryl with two groups of biomimetic ligands, peptides and MIPs was screened by multiple minima hypersurfaces (MMH) procedures, through the AM1 semiempirical method. Data related to the properties of the molecular association of the complex biomimetic ligand-pesticide were obtained and compared with another molecular modeling algorithm named Leapfrog, as included in the Sybyl software package, and experimental results from the literature, remarking good correlation between them. All important MMH program parameters (cells number, box size, conformers) were studied and optimized with the aim of getting the minimum computation time without losing the correlation with experimental data. The data demonstrated that MMH approach can be used as a fast biomimetic ligand screening tool for MIPs. In the case of peptides the computation time was not comparable with the molecular dynamics methods conventionally used for this approach. © 2011 Springer Science+Business Media B.V.

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This paper presents a method for indirect orientation of aerial images using ground control lines extracted from airborne Laser system (ALS) data. This data integration strategy has shown good potential in the automation of photogrammetric tasks, including the indirect orientation of images. The most important characteristic of the proposed approach is that the exterior orientation parameters (EOP) of a single or multiple images can be automatically computed with a space resection procedure from data derived from different sensors. The suggested method works as follows. Firstly, the straight lines are automatically extracted in the digital aerial image (s) and in the intensity image derived from an ALS data-set (S). Then, correspondence between s and S is automatically determined. A line-based coplanarity model that establishes the relationship between straight lines in the object and in the image space is used to estimate the EOP with the iterated extended Kalman filtering (IEKF). Implementation and testing of the method have employed data from different sensors. Experiments were conducted to assess the proposed method and the results obtained showed that the estimation of the EOP is function of ALS positional accuracy.

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The X-ray Fluorescence (XRF) analysis is a technique for the qualitative and quantitative determination of chemical constituents in a sample. This method is based on detection of the characteristic radiation intensities emitted by the elements of the sample, when properly excited. A variant of this technique is the Total Reflection X-ray Fluorescence (TXRF) that utilizes electromagnetic radiation as excitation source. In total reflection of X-ray, the angle of refraction of the incident beam tends to zero and the refracted beam is tangent to the sample support interface. Thus, there is a minimum angle of incidence at which no refracted beam exists and all incident radiation undergoes total reflection. In this study, we evaluated the influence of the energy variation of the beam of incident x-rays, using the MCNPX code (Monte Carlo NParticle) based on Monte Carlo method. © 2013 AIP Publishing LLC.

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A novel method of preparation of the Si nanoparticles (NPs) incorporated in tellurite TeO2-WO3-Bi2O3 (TWB) thin films is proposed. This mew method applies RF magnetron sputtering technique at room temperature. The incorporation of Si NP was confirmed by transmission electron microscopy (TEM); isolated Si NPs with diameters of around 6 nm are observed. Energy dispersive X-ray spectroscopy (EDS) was performed during TEM analysis in order to confirm the presence of Si NP and also the other elements of the thin film. The thin films are explored with respect to the photoinduced changes of the reflectivity within the 400-65 nm spectra range using a 10 ns pulsed Nd:YAG with power densities varying up to 400 MW/cm2 and beam diameter within the 3-5 mm range. The observed processes are analyzed within a framework of trapping level conceptions for the Si NP. The possible application of the discovered materials as optical sensitive sensors is proposed. © 2013 Elsevier B.V.

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This study presents a new methodology based on risk/investment to solve transmission network expansion planning (TNEP) problem with multiple future scenarios. Three mathematical models related to TNEP problems considering multiple future generation and load scenarios are also presented. These models will provide planners with a meaningful risk assessment that enable them to determine the necessary funding for transmission lines at a permissible risk level. The results using test and real systems show that the proposed method presents better solutions compared with scenario analysis method. ©The Institution of Engineering and Technology 2013.

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Pós-graduação em Linguística e Língua Portuguesa - FCLAR

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O objetivo deste estudo foi investigar como se deu o desenvolvimento profissional de quatro professoras de matemática que lecionam na Rede Pública Estadual em Araguaína - Tocantins. Para compreender o processo de desenvolvimento profissional das professoras, adotou-se como método a pesquisa qualitativa, com enfoque narrativo, com base em entrevistas semi-estruturadas. Alicerçado em um conceito de desenvolvimento profissional tomado numa perspectiva contínua, idealizado num contexto mais amplo do trabalho docente, permeando crises, conflitos, angústias e desilusões, o estudo evidencia, no contexto dos resultados obtidos, que as múltiplas experiências vividas pelas quatro professoras constituem-se base principal de todo o seu desenvolvimento profissional. Por intermédio deste estudo, foi possível perceber que as professoras vivenciaram mudanças em seu percurso profissional, e que essas, ao se transformarem, foram modificando sua concepção e postura diante do conhecimento e da prática pedagógica. Tal mudança não se deu sem estudo, sem crises e conflitos, sem reflexão, sem o eu e o outro, sem correr e assumir riscos.

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Nas bacias sedimentares da região Amazônica, a geração e o acúmulo de hidrocarboneto estão relacionados com a presença das soleiras de diabásio. Estas rochas magmáticas intrusivas possuem grandes contrastes de impedância com as rochas sedimentares encaixantes, resultando em múltiplas externas e internas, com amplitudes semelhantes às das reflexões sísmicas primárias. Estas múltiplas podem predominar sobre as informações oriundas de interfaces mais profundas, dificultando o processamento, a interpretação e o imageamento da seção de sísmica. O objetivo da presente tese é realizar a atenuação de múltiplas em seções sintéticas fontecomum (CS), através da combinação dos métodos Wiener-Hopf-Levinson de predição (WHLP) e o do empilhamento superfície-de-reflexão-comum (CRS), aqui denominando pela sigla WHLPCRS. O operador de deconvolução é calculado com as amplitudes reais do sinal sísmico e traço-a-traço, o que consideramos como uma melhor eficiência para a operação de atenuação. A identificação das múltiplas é feita na seção de afastamento-nulo (AN) simulada com o empilhamento CRS, utilizando o critério da periodicidade entre primária e suas múltiplas. Os atributos da frente de onda, obtidos através do empilhamento CRS, são utilizados na definição de janelas móveis no domínio tempo-espaço, e usados para calcular o operador WHLP-CRS. No desenvolvimento do presente trabalho, visamos evitar a inconveniência da seção processada ZO; desenhar e aplicar operadores na configuração CS; e estender o método WHL para camadas curvas.

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The use of markers distributed all long the genome may increase the accuracy of the predicted additive genetic value of young animals that are candidates to be selected as reproducers. In commercial herds, due to the cost of genotyping, only some animals are genotyped and procedures, divided in two or three steps, are done in order to include these genomic data in genetic evaluation. However, genomic evaluation may be calculated using one unified step that combines phenotypic data, pedigree and genomics. The aim of the study was to compare a multiple-trait model using only pedigree information with another using pedigree and genomic data. In this study, 9,318 lactations from 3061 buffaloes were used, 384 buffaloes were genotyped using a Illumina bovine chip (Illumina Infinium (R) bovineHD BeadChip). Seven traits were analyzed milk yield (MY), fat yield (FY), protein yield (PY), lactose yield (LY), fat percentage (F%), protein percentage (P%) and somatic cell score (SCSt). Two analyses were done: one using phenotypic and pedigree information (matrix A) and in the other using a matrix based in pedigree and genomic information (one step, matrix H). The (co) variance components were estimated using multiple-trait analysis by Bayesian inference method, applying an animal model, through Gibbs sampling. The model included the fixed effects of contemporary groups (herd-year-calving season), number of milking (2 levels), and age of buffalo at calving as (co) variable (quadratic and linear effect). The additive genetic, permanent environmental, and residual effects were included as random effects in the model. The heritability estimates using matrix A were 0.25, 0.22, 0.26, 0.17, 0.37, 0.42 and 0.26 and using matrix H were 0.25, 0.24, 0.26, 0.18, 0.38, 0.46 and 0.26 for MY, FY, PY, LY, % F, % P and SCCt, respectively. The estimates of the additive genetic effect for the traits were similar in both analyses, but the accuracy were bigger using matrix H (superior to 15% for traits studied). The heritability estimates were moderated indicating genetic gain under selection. The use of genomic information in the analyses increases the accuracy. It permits a better estimation of the additive genetic value of the animals.

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In this article, we discuss the contributions of Didactics for intentional pedagogical action of teachers devoted to children education. In this sense, we initially say to be essential the reflections which aim to search for foundations focused on the mobilization of future teachers for the action-reflection-action about the educational phenomena, aiming at the unveiling, with rigor and objectivity, of its multiple determinations within the capitalist relations . We believe that such unveiling is only possible in the light of a world view, a method and a praxis constituted in unison with historical materialism and its dialectic. Afterwards, we reflect on some of the principles of the Historical-Cultural Theory to understand of the active and mediator role teachers have in the process of humanization of young children and contributions of dialectical materialism to this reflection. Finally are detailed some aspects of a Didactics focused on training teachers for Children and early elementary school years’ education, which have guided our actions as teachers of the Pedagogy Course and reiterated by teachers’ narratives about their experience both in life and teaching, in search of new systematization modes, targeting an educational praxis due to the redefinition (theorization) and on the teaching practice by its very subjects.

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This text is mainly aimed to address essential aspects of teacher formation in the light of education-work relations in the higher education, from our systematic experience in higher education teaching, particularly teaching and research in the field of Didactics discipline. This formulation is justified considering our concern in seeking to situate this discussion in the context of bringing together knowledge areas and the field of teaching knowledge. Still, our choice to develop such an approach in the light of work-education relationship is due to the belief about the possibilities of seeking to overcome the requirements imposed by capitalism to our educational system, within the possible contradictions of these relationships. In this context the teachers’ formation in higher education gains social and strategic importance, taking on the task of forming individuals of “action-reflection-action” in a society established historically based on the social relations which settle in the light of capital’s multiple determinations. It appears that, in this sense, the major confrontations have been given within the discussions about what to prioritize or combine in the list of criteria and content for teacher’s formation. In Didactic, we seek to emphasize discussions that we consider with a philosophical background, referring to the orientation of teaching practice in knowledge of contemporary ideological struggle; socio-historical, referring to the possibility of formation of disciplines, among them Didactic, and curriculums and references to support its guidance in the process of teacher’s formation. This context of discussion is based on the concrete teaching practice with a view to transformation and to search for new syntheses in terms of knowledge and in terms of historical reality. Then therefore, our methodological approach grounded in the dimensions of the same unit: historical materialism as posture, method and as praxis.

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The increasing amount of sequences stored in genomic databases has become unfeasible to the sequential analysis. Then, the parallel computing brought its power to the Bioinformatics through parallel algorithms to align and analyze the sequences, providing improvements mainly in the running time of these algorithms. In many situations, the parallel strategy contributes to reducing the computational complexity of the big problems. This work shows some results obtained by an implementation of a parallel score estimating technique for the score matrix calculation stage, which is the first stage of a progressive multiple sequence alignment. The performance and quality of the parallel score estimating are compared with the results of a dynamic programming approach also implemented in parallel. This comparison shows a significant reduction of running time. Moreover, the quality of the final alignment, using the new strategy, is analyzed and compared with the quality of the approach with dynamic programming.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Aim: The aim of this report is to describe a quick and simple method of positioning retention magnets when deformed patients are rehabilitated with an oculopalpebral prostheses attached to a maxillary denture/obturator. Background: In patients with deformities requiring complex rehabilitations, the use of magnets is the most efficient means of providing combined prostheses with retention quality and stability. Usually prostheses with magnets are in sections and have a magnet in each section. When the sections are put together properly, the magnets are attracted to each other and retain the sections. Report: An edentulous patient presented for a post-surgical evaluation of a maxillofacial prosthesis used to repair a partial maxillectomy and left orbital exoneration which removed all adjacent tissues leaving an open communication between the oral, nasal, and orbital cavities. The proposed treatment plan included construction of a maxillary complete denture with a palatal obturator and a mandibular complete denture. Magnets were used to attach the oculopalpebral prosthesis to the maxillary denture/obturator. Summary: Use of retention magnets simplify the clinical and laboratorial phase, retains the denture, and makes it stable and comfortable for the patient. This treatment is one successful approach to the restoration of oral function and increases the patient’s quality of life.