Investigation for long wavelength FIR laser lines for EPR studies: New lines from CH2=CF2

The results described in this work are part of a systematic search for long wavelength laser lines to be used in high magnetic field EPR applications and in plasma diagnostic. Four new far-infrared laser lines of CH2 = CF2 (1,1 difluoroethylene), optically pumped by a waveguide CO2 laser, have been discovered and characterized in wavelength, polarization relative to the pumping radiation and offset relative to the CO2 center frequency. New measurements of polarization and offset of 5 already known laser lines are also reported. A table of all of the known CO2 pumped FIR laser lines from this molecule is given.

Modal representation of three-phase lines applying two transformation matrices: Evaluation of its eigenvectors

The objective of this paper is to show an alternative representation in time domain of a non-transposed three-phase transmission line decomposed in its exact modes by using two transformation matrices. The first matrix is Clarke's matrix that is real, frequency independent, easily represented in computational transient programs (EMTP) and separates the line into Quasi-modes alpha, beta and zero. After that, Quasi-modes a and zero are decomposed into their exact modes by using a modal transformation matrix whose elements can be synthesized in time domain through standard curve-fitting techniques. The main advantage of this alternative representation is to reduce the processing time because a frequency dependent modal transformation matrix of a three-phase line has nine elements to be represented in time domain while a modal transformation matrix of a two-phase line has only four elements. This paper shows modal decomposition process and eigenvectors of a nontransposed three-phase line with a vertical symmetry plane whose nominal voltage is 440 kV and line length is 500 km.

Magnetic field of an in-plane vortex inside and outside a layered superconducting film

In the present work we study an anisotropic layered superconducting film of finite thickness. The film surfaces are considered parallel to the be face of the crystal. The vortex lines are oriented perpendicular to the film surfaces and parallel to the superconducting planes. We calculate the local field and the London free energy for this geometry. Our calculation is a generalization of previous works where the sample is taken as a semi-infinite superconductor. As an application of this theory we investigate the flux spreading at the super conducting surface.

INFLUENCE of HIP EXTERNAL ROTATION on HIP ADDUCTOR and RECTUS FEMORIS MYOELECTRIC ACTIVITY DURING A DYNAMIC PARALLEL SQUAT

Pereira, GR, Leporace, G, Chagas, DV, Furtado, LFL, Praxedes, J, and Batista, LA. Influence of hip external rotation on hip adductor and rectus femoris myoelectric activity during a dynamic parallel squat. J Strength Cond Res 24(10): 27492754, 2010-This study sought to compare the myoelectric activity of the hip adductors (HAs) and rectus femoris (RF) when the hip was in a neutral position or externally rotated by 30 degrees or 50 degrees (H0, H30, and H50, respectively) during a parallel squat. Ten healthy subjects performed 10 repetitions of squats in each of the 3 hip positions and the myoelectric activities of the HAs and RF were recorded. The signal was then divided into categories representing concentric (C) and eccentric (E) contractions in the following ranges of motion: 0-30 degrees (C1 and E1), 30-60 degrees (C2 and E2), and 60-90 degrees (C3 and E3) of knee flexion. From those signals, an root mean square (RMS) value for each range of motion in each hip position was obtained. All values were normalized to those obtained during maximum voluntary isometric contraction. We found that HAs showed a significant increase in myoelectric activity during C3 and E3 in the H30 and H50 positions, as compared with H0. Meanwhile, RF activity did not significantly differ between hip positions. Both muscles showed higher activation during 60-90 degrees (C3 and E3) of knee flexion, as compared with 0-30 degrees (C1 and E1) and 30-60 degrees (C2 and E2). The results suggest that if the aim is to increase HA activity despite the low percentage of muscle activation, squats should be performed with 30 degrees of external rotation and at least 90 degrees of knee flexion.

Analyses of the modifications in the pi circuits for inclusion of frequency influence in transmission line representation

In this article, it is represented by state variables phase a transmission line which parameters are considered frequency independently and frequency dependent. It is analyzed what is the reasonable number of pi circuits and the number of blocks composed by parallel resistor and inductor in parallel for reduction of numerical oscillations. It is simulated the numerical routine with and without the effect of frequency in the longitudinal parameters. Initially, it is used state variables and pi circuits representing the transmission line composing a linear system which is solved by numerical routines based on the trapezoidal rule. The effect of frequency on the line is synthesized by resistors and inductors in parallel and this representation is analyzed in details. It is described transmission lines and the frequency influence in these lines through the state variables.

The Use of Etoricoxib and Celecoxib for Pain Prevention After Periodontal Surgery: A Double-Masked, Parallel-Group, Placebo-Controlled, Randomized Clinical Trial

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of Wood Moisture Content on the Modulus of Elasticity in Compression Parallel to the Grain

Brazilian Standard ABNT NBR7190:1997 for timber structures design, adopts a first degree equation to describe the influence of wood moisture content. Periodically, when necessary, the referred standard is revised in order to analyze inconsistencies and to adopt considerations according new realities verified. So, the present paper aims to examine the adequacy of its equation which corrects to 12% of moisture the values of rigidity properties obtained on experimental tests. To quantify the moisture influence on modulus of elasticity, it was applied tests of compression parallel to the grain for six specimens of different strength classes, considering nominal moisture of 12; 20; 25; 30%. As results, modulus of elasticity in the moisture range 25-30% showed statistically equivalents, and was obtained a first degree equation to correlate the studied variables which leads to statically equivalent estimations when compared with results by ABNT NBR7190:1997 equation. However, it was indicated to maintain the current expression for the next text of the referred document review, without prejudice to statistical significance of the estimates.

Time Domain Analyses for Three-phase Lines with Corrected Modal Transformation Matrix

The results presented in this paper are based on a research about the application of approximated transformation matrices for electromagnetic transient analyses and simulations in transmission lines. Initially, it has developed the application of a single real transformation matrix for a double three-phase transmission lines, because the symmetry of the distribution of the phase conductors and the ground wires. After this, the same type of transformation matrix has applied for symmetrical single three-phase transmission lines. Analyzing asymmetrical single three-phase lines, it has used three different line configurations. For these transmission line types, the errors between the eigenvalues and the approximated results, called quasi modes, have been considered negligible. on the other hand, the quasi mode eigenvalue matrix for each case was not a diagonal one. and the relative values of the off-diagonal elements of the approximated quasi mode matrix are not negligible, mainly for the low frequencies. Based on this problem, a correction procedure has been applied for minimizing the mentioned relative values. For the correction procedure application, symmetrical and asymmetrical single three-phase transmission line samples have been used. Checking the correction procedure results, analyses and simulations have been carried out in mode and time domain. In this paper, the last results of mentioned research are presented and they related to the time domain simulations.

Harmonic identification using parallel neural networks in single-phase systems

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determination and statistical treatment of short-circuit currents for faults on the lines of networks of 440 kV CESP system

The distribution of short-circuit current is investigated by means of two methods, one direct and the other analytic; both methods consider uniform probability distribution of line faults. In the direct method, the procedure consists of calculating fault currents at equidistant points along the line, starting from one of the end points and considering the other end open. The magnitude of the current is classified according to Brazilian standards (regulation NBR-7118). The analytic method assumes that the distribution of short-circuit currents through the busbar and the distribution of the line length connected to it are known, as well as the independence of values. The method is designed to determine the probability that fault currents through a line will surpass the pre-established magnitude, thus generating frequency distribution curves of short-circuit currents along the lines.

A recursive approach to space resection using straight lines

An approach using straight lines as features to solve the photogrammetric space resection problem is presented. An explicit mathematical model relating straight lines, in both object and image space, is used. Based on this model, Kalman Filtering is applied to solve the space resection problem. The recursive property of the filter is used in an iterative process which uses the sequentially estimated camera location parameters to feedback to the feature extraction process in the image. This feedback process leads to a gradual reduction of the image space for feature searching, and consequently eliminates the bottleneck due to the high computational cost of the image segmentation phase. It also enables feature extraction and the determination of feature correspondence in image and object space in an automatic way, i.e., without operator interference. Results obtained from simulated and real data show that highly accurate space resection parameters are obtained as well as a progressive processing time reduction. The obtained accuracy, the automatic correspondence process, and the short related processing time show that the proposed approach can be used in many real-time machine vision systems, making possible the implementation of applications not feasible until now.

Interaction potential between vortex lines for uniaxial superconductors in the London approximation

Two distinct expressions of the interaction potential between arbitrarily oriented curved vortex lines with respect to the crystal c axis are derived within the London approximation. One of these expressions is used to compute the eigenvalues of the elasticity matrix. We examine the elastic properties of the vortex chain lattice, recently proposed, concerning shearing deformation.

Translating conduction-electron spin-resonance lines into lorentzian lines

The Dysonian line in the limit d < or ∼ δ, where d is the thickness and 6 the skin depth, was fitted to a combination of absorption and dispersion Lorentzian lines. This procedure allows one to determine not only microwave conductivity from the Dysonian line but also the true g value, linewidth, and paramagnetic susceptibility by the measurement of five parameters of the ESR absorption-derivative Dysonian line. ©1990 Academic Press, inc.