Para-orthogonal polynomials from constant Verblunsky coefficients

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Michelson interferometer vibrometer using self-correcting synthetic-heterodyne demodulation

Synthetic-heterodyne demodulation is a useful technique for dynamic displacement and velocity detection in interferometric sensors, as it can provide an output signal that is immune to interferometric drift. With the advent of cost-effective, high-speed real-time signal-processing systems and software, processing of the complex signals encountered in interferometry has become more feasible. In synthetic heterodyne, to obtain the actual dynamic displacement or vibration of the object under test requires knowledge of the interferometer visibility and also the argument of two Bessel functions. In this paper, a method is described for determining the former and setting the Bessel function argument to a set value, which ensures maximum sensitivity. Conventional synthetic-heterodyne demodulation requires the use of two in-phase local oscillators; however, the relative phase of these oscillators relative to the interferometric signal is unknown. It is shown that, by using two additional quadrature local oscillators, a demodulated signal can be obtained that is independent of this phase difference. The experimental interferometer is aMichelson configuration using a visible single-mode laser, whose current is sinusoidally modulated at a frequency of 20 kHz. The detected interferometer output is acquired using a 250 kHz analog-to-digital converter and processed in real time. The system is used to measure the displacement sensitivity frequency response and linearity of a piezoelectric mirror shifter over a range of 500 Hz to 10 kHz. The experimental results show good agreement with two data-obtained independent techniques: the signal coincidence and denominated n-commuted Pernick method.

Aplicação do sistema de biosusceptometria AC para monitoramento de nanopartículas magnéticas na circulação sanguínea

Pós-graduação em Biologia Geral e Aplicada - IBB

Projeto de controladores robustos para acionamento de um motor de indução trifásico

Pós-graduação em Engenharia Elétrica - FEIS

Suppression of vibrations in a nonlinear half-car model using a magneto-rheological damper

The present work investigates the nonlinear response of a half-car model. The disturbances of the road are assumed to be sinusoidal. After constructing the bifurcation diagram, we use the 0-1 test to identify chaotic motions. The main objective of this study is to eliminate chaotic behavior of the chassis and reduce its vibrations. To accomplish this, a semi-active vehicle suspension control system, using magneto-rheological dampers, is proposed. The proposed semi-active control strategy consists of two nonlinear control laws: a feedforward control, and a feedback control. They are obtained by considering the SDRE (State Dependent Riccati Equation) control, where the control parameter is the voltage applied to the coils of the magneto-rheological dampers. Numerical results show that the proposed control method is effective in significantly reducing of the chassis vibration, increasing, therefore, passenger comfort.

Caracterização biofísica da interação entre a proteína M2-1 do Vírus Sincicial Respiratório Humano (HRSV) com quercetina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modelos lineares generalizados bayesianos para dados longitudinais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aplicação de projeto de experimento no processo de manufatura de uma bobina de alumínio

TProducts must follow specifications in order to attend demands requested. In terms of rolled aluminum, one of the most significant items for customers is coil thickness. This is because only a tiny variation in thickness might cause a serious problem on customer's manufacturing line. Thereby, this research aims to analyze through design of experiments which factors and how they affect the thickness of aluminum coils. The response variable of the experiment is the thickness of aluminum coil, tensile strenght and yield strenght are the factors of the experiment and trimmers machines were considered as blocking. Data were obtained through tensile tests. The result of the experiment states that, according to the analysis of variance (ANOVA), while there is significant difference between the two levels of tensile strength, there is not any difference between the two levels of yield strength and trimmers machines. The thickness of the aluminum coils with high values of tensile strength tends to be thicker when compared with low values of tensile strength

Myxobolus mississippiensis n. sp. (Myxosporea) from Gills of Lepomis macrochirus in Mississippi

Myxobolus mississippiensis n. sp. is described from gill lamellae of the bluegill (Lepomis macrochirus) inhabiting the Pascagoula River System, Mississippi. Fresh spores measure 16.4-18.7 μm long, 3.9-6.2 μm wide, and 4.7-6.2 μm thick. Spore width to length ratio is 1:3.2. Polar capsules are 5.5-7.8 μm long and 1.5-2.3 μm wide, with 9-10 filament coils that when extruded measure 42.1 ± 4.2 μm. This parasite is unique among known species of Myxobolus,/i> in having spores that are lenticular in frontal view.

Aplicação de projeto de experimento no processo de manufatura de uma bobina de alumínio

TProducts must follow specifications in order to attend demands requested. In terms of rolled aluminum, one of the most significant items for customers is coil thickness. This is because only a tiny variation in thickness might cause a serious problem on customer's manufacturing line. Thereby, this research aims to analyze through design of experiments which factors and how they affect the thickness of aluminum coils. The response variable of the experiment is the thickness of aluminum coil, tensile strenght and yield strenght are the factors of the experiment and trimmers machines were considered as blocking. Data were obtained through tensile tests. The result of the experiment states that, according to the analysis of variance (ANOVA), while there is significant difference between the two levels of tensile strength, there is not any difference between the two levels of yield strength and trimmers machines. The thickness of the aluminum coils with high values of tensile strength tends to be thicker when compared with low values of tensile strength

Decision-directed feedback equalisation for QAM signals

Proposed is a symbol-based decision-directed algorithm for blind equalisation of quadrature amplitude modulation (QAM) signals using a decision feedback scheme. Independently of QAM order, it presents: (i) an error equal to zero when the equaliser output coincides with the transmitted signal; (ii) simultaneous recovery of the modulus and phase of the signal; (iii) a misadjustment close to that of the normalised least-mean squares algorithm; (iv) fast convergence; and (v) the avoidance of degenerative solutions. Additionally, its stability is ensured when the step-size is properly chosen.

Septin C-Terminal Domain Interactions: Implications for Filament Stability and Assembly

Septins form a conserved family of filament forming GTP binding proteins found in a wide range of eukaryotic cells. They share a common structural architecture consisting of an N-terminal domain, a central GTP binding domain and a C-terminal domain, which is often predicted to adopt a coiled-coil conformation, at least in part. The crystal structure of the human SEPT2/SEPT6/SEPT7 heterocomplex has revealed the importance of the GTP binding domain in filament formation, but surprisingly no electron density was observed for the C-terminal domains and their function remains obscure. The dearth of structural information concerning the C-terminal region has motivated the present study in which the putative C-terminal domains of human SEPT2, SEPT6 and SEPT7 were expressed in E. coli and purified to homogeneity. The thermal stability and secondary structure content of the domains were studied by circular dichroism spectroscopy, and homo- and hetero-interactions were investigated by size exclusion chromatography, chemical cross-linking, analytical ultracentrifugation and surface plasmon resonance. Our results show that SEPT6-C and SEPT7-C are able to form both homo- and heterodimers with a high alpha-helical content in solution. The heterodimer is elongated and considerably more stable than the homodimers, with a K (D) of 15.8 nM. On the other hand, the homodimer SEPT2-C has a much lower affinity, with a K (D) of 4 mu M, and a moderate alpha-helical content. Our findings present the first direct experimental evidence toward better understanding the biophysical properties and coiled-coil pairings of such domains and their potential role in filament assembly and stability.

Residence Time Distribution Models Derived from Non-Ideal Laminar Velocity Profiles in Tubes

The theoretical E-curve for the laminar flow of non-Newtonian fluids in circular tubes may not be accurate for real tubular systems with diffusion, mechanical vibration, wall roughness, pipe fittings, curves, coils, or corrugated walls. Deviations from the idealized laminar flow reactor (LFR) cannot be well represented using the axial dispersion or the tanks-in-series models of residence time distribution (RTD). In this work, four RTD models derived from non-ideal velocity profiles in segregated tube flow are proposed. They were used to represent the RTD of three tubular systems working with Newtonian and pseudoplastic fluids. Other RTD models were considered for comparison. The proposed models provided good adjustments, and it was possible to determine the active volumes. It is expected that these models can be useful for the analysis of LFR or for the evaluation of continuous thermal processing of viscous foods.

Coronary to Bronchial Artery Fistula: Are We Treating it Right?

Fistulas between coronary artery and bronchial artery may be present from birth, with few hemodynamic consequences, and may remain closed due to similarity of the filling pressures at these 2 sites.(1) They can also be secondary to pulmonary artery occlusive disease or chronic pulmonary inflammation.(2,3) These pulmonary changes may cause a dilation of the fistula and make it functional, causing angina pectoris by coronary steal syndrome, which is the most common symptom. The presentation may also be composed of episodes of hemoptysis, heart failure, and infective endocarditis. However, most patients remain asymptomatic. The ones that need treatment may not have a good response to the medical management, requiring an intervention. This can be done using embolization coils, stents grafts, and performing surgical ligation of the fistulas.(2-4) J INVASIVE CARDIOL 2012;24(11):E303-E304

A regional multirnodulus algorithm for blind equalization of QAM signals: Introduction and steady-state analysis

It is well known that constant-modulus-based algorithms present a large mean-square error for high-order quadrature amplitude modulation (QAM) signals, which may damage the switching to decision-directed-based algorithms. In this paper, we introduce a regional multimodulus algorithm for blind equalization of QAM signals that performs similar to the supervised normalized least-mean-squares (NLMS) algorithm, independently of the QAM order. We find a theoretical relation between the coefficient vector of the proposed algorithm and the Wiener solution and also provide theoretical models for the steady-state excess mean-square error in a nonstationary environment. The proposed algorithm in conjunction with strategies to speed up its convergence and to avoid divergence can bypass the switching mechanism between the blind mode and the decision-directed mode. (c) 2012 Elsevier B.V. All rights reserved.