Geochronology of the lpanema layered mafic-ultramafic complex, Minas gerais, Brazil: Evidence of extension at the meso-neoproterozoic time boundary

The mafic/ultramafic Ipanema Layered Complex (ILC), Minas Gerais Brazil, consists of seven individual bodies. These units crosscut polyphase orthogneisses and interlayered paragneisses of the Paleoproterozoic Juiz de Fora Complex. Intrusive granitoids tectonically related to [lie Neoproterozoie Aracuai orogen are also present in the study area.A Sm-Nd whole-rock linear array for seven samples metapyoxenites, metaperidotiles, metagabbro. and meta-anorthosite) from the Santa Cruz massif, the largest body of the ILC. suggest that it was emplaced at 1104 +/- 78 Ma the original magma was derived from a depleted mantle source (epsilon(Ndt)= +3.8). U-Pb single-grain zircon stud of a meta-anorthosite yields all upper intercept age of 1719 +/- 4 Ma, which is interpreted to represent inheritance. The lower intercept at 630+/-3 Ma indicates (hat a Neoproterozoic tectonothermal episode overprinted the ILC, this event occurred under upper-amphiolite-, to granulite-facies conditions. The 630 Ma episode is consistent with the timing of regional metamorphism and deformation of the adjacent Aracuai orogen (Brasiliano collage). Emplacement of the ILC and other coeval metamafies and meta-ultramafics (of alkaline affinity) in the re, oil is attributed to early extension tectonics, accompanying accretion of the Rodinia super- continent during the Mesoproterozoic-Neoproterozoic time boundary.

Design of a fuzzy Takagi-Sugeno controller to vary the joint knee angle of paraplegic patients

The papers shows, through theoretical studies and simulations, that using the description of the plant by Takagi-Sugeno (T-S), it is possible to design a nonlinear controller to control the position of the leg of a paraplegic patient. The control system was designed to change the angle of the joint knee of 60 degrees. This is the first study that describes the application of Takagi-Sugeno (T-S) models in this kind of problem.

Effects of high intensity running to fatigue on isokinetic muscular strength in endurance athletes

The objective of this study was to examine the effects of high intensity exhaustive running exercise on the muscular torque capacity of the knee extensors for two types of contraction (concentric and eccentric) at different angular velocities (60 and 180 degrees/s) in well-trained runners. Eleven male runners specialized in middle and long-distance running volunteered to participate in this study. Initially each subject performed, on different days, two familiarization sessions on an isokinetic dynamometer and an incremental treadmill test to volitional exhaustion to determine the velocity associated with the onset of blood lactate accumulation (OBLA). The subjects then returned to the laboratory on two occasions, separated by at least seven days, to perform maximal isokinetic knee contractions at each of the velocities under eccentric (Ecc) and concentric (Con) conditions. Conducted randomly, one test was performed after a standardized warm-up period of 5 min at 50% VO2 max. The other test was performed 15 min after continuous running at OBLA until volitional exhaustion. Following this high intensity exercise there was a significant reduction of Con at 60 degrees/s and a significant reduction of Ecc at both velocities. Percent strength losses after running exercise were significantly different between contraction types only at 180 degrees/s. We can conclude that the reduction in isokinetic peak torque of the knee extensors after a session of high intensity exhaustive running exercise at OBLA depends on the contraction type and angular velocity.

Load torque estimation in induction motors using artificial neural networks

The induction motors are largely used in several industry sectors. The dimensioning of an induction motor has still been inaccurate because in most of the cases the load behavior in its shaft is completely unknown. The proposal of this paper is to use artificial neural networks as tool for dimensioning of induction motors rather than conventional methods, which use classical identification techniques and mechanical load modeling. Simulation results are also presented to validate the proposed approach.

Effect of 17 beta-estradiol and alendronate on the removal torque of osseointegrated titanium implants in ovariectomized rats

Background: This study investigated the influence of estrogen deficiency and its treatment with estrogen and alendronate on the removal torque of osseointegrated titanium implants.Methods: Fifty-eight female Wistar rats received a titanium implant in the tibia metaphysis. After 60 days, which was needed for implant osseointegration, the animals were randomly divided into five groups: control (CTLE; N = 10), sham surgery (SHAM; N = 12), ovariectomy (OVX; N = 12), ovariectomy followed by hormone replacement (EST; N = 12), and ovariectomy followed by treatment with alendronate (ALE; N = 12). The CTLE group was sacrificed to confirm osseointegration, whereas the remaining groups were submitted to sham surgery or ovariectomy according to their designations. After 90 days, these animals were also sacrificed. Densitometry of femur and lumbar vertebrae was performed by dual-energy x-ray absorptiometry (DXA) to confirm systemic impairment of the animals. All implants were subjected to removal torque.Results: Densitometric analysis of the femur and lumbar vertebrae confirmed a systemic impairment of the animals, disclosing lower values of bone mineral density for OVX. Analysis of the removal torque of the implants showed statistically lower values (P <0.05) for the OVX group in relation to the other groups. However, the group treated with alendronate (ALE group) presented significantly higher torque values compared to the others.Conclusion: According to this study, estrogen deficiency was observed to have a negative influence on the removal torque of osseointegrated implants, whereas treatment with alendronate

Proprioceptive and behavior impairments in individuals with anterior cruciate ligament reconstructed knees

Objective: To assess sensory deficits and their effects on proprioceptive and motor function in patients who had undergone unilateral anterior cruciate ligament (ACL) reconstruction.Design: Four evaluations were conducted: (1) joint position perception of the knee for predetermined angles (0degrees, 15degrees, 30degrees, 45degrees, 60degrees); (2) threshold for detection of passive knee motion at 0degrees, 15degrees, 30degrees, 45degrees, and 60degrees moving into flexion and at 15degrees, 30degrees, 45degrees, and 60degrees moving into extension; (3) latency onset of hamstring muscles; and (4) postural control during upright double- and single-leg stance.Setting: Movement laboratory in Brazil.Participants: Ten participants who had surgical reconstruction of the ACL (reconstructed group) and 10 participants without knee injury (control group).Interventions: Not applicable.Main Outcome Measures: Absolute error, angular displacement, hamstring muscles latency, and mean sway amplitude.Results: Individuals with a reconstructed knee showed decreased joint position perception, a higher threshold for detection of passive knee motion, longer latency of hamstring muscles, and decreased performance in postural control.Conclusions: After lesion and ACL reconstruction, sensory and motor behavior changes were still observed. This may be because of the lack of proprioceptive information resulting from the ACL lesion and/or substitution of ACL by the graft. (C) 2003 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.

Analytical attitude propagation with non-singular variables and gravity gradient torque for spin stabilized satellite

An analytical approach for the spin stabilized satellite attitude propagation is presented using the non-singular canonical variables to describe the rotational motion. Two sets of variables were introduced for Fukushima in 1994 by a canonical transformation and they are useful when the angle between z-satellite axis of a coordinate system fixed in artificial satellite and the rotational angular momentum vector is zero or when the angle between Z-equatorial axis and rotation angular momentum vector is zero. Analytical solutions for rotational motion equations and torque-free motion are discussed in terms of the elliptic functions and by the application of some simplification to get an approximated solution. These solutions are compared with a numerical solution and the results show a good agreement for many rotation periods. When the mean Hamiltonian associated with the gravity gradient torque is included, an analytical solution is obtained by the application of the successive approximations' method for the satellite in an elliptical orbit. These solutions show that the magnitude of the rotation angular moment is not affected by the gravity gradient torque but this torque causes linear and periodic variations in the angular variables, long and short periodic variations in Z-equatorial component of the rotation angular moment and short periodic variations in x-satellite component of the rotation angular moment. The goal of this analysis is to emphasize the geometrical and physical meaning of the non-singular variables and to validate the approximated analytical solution for the rotational motion without elliptic functions for a non-symmetrical satellite. The analysis can be applied for spin stabilized satellite and in this case the general solution and the approximated solution are coincidence. Then the results can be used in analysis of the space mission of the Brazilian Satellites. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

Completeness of coherent states associated with self-similar potentials and Ramanujan's integral extension of the beta function

A decomposition of identity is given as a complex integral over the coherent states associated with a class of shape-invariant self-similar potentials. There is a remarkable connection between these coherent states and Ramanujan's integral extension of the beta function.

Accuracy of Mechanical Torque Devices for Implants Used in Brazilian Dental Offices

The purpose of this study was to determine the accuracy of mechanical torque devices in delivering target torque values in dental offices in Salvador, Brazil. A team of researchers visited 16 dental offices, and the clinicians applied torque values (20 and 32 Ncm) to electronic torque controllers. Five repetitions were completed at each torque value and data were collected. When 20 Ncm of torque was used, 62.5% of measured values were accurate (within 10% of the target value). For 32 Ncm, however, only 37.5% of these values were achieved. Several of the tested mechanical torque devices were inaccurate. Int J Prosthodont 2011;24:38-39.

Temperature rise in cavities prepared by high and low torque handpieces and Er : YAG laser

Objective The aim of this study was to compare intrapulpal temperature increases produced by a high-speed high-torque (speed-increasing) handpiece, a high-speed low-torque handpiece (air-turbine) and an Er: YAG (Erbium: Yttrium-Aluminum-Garnet) laser. Subject and methods Thirty bovine incisors were reduced to a dentine thickness of 2.0 mm. Class V preparations were prepared to a depth of 1.5 mm, measured with a caliper or by a mark on the burs. A thermocouple was placed inside the pulp chamber to determine temperature increases (C). Analysis was performed on the following groups (n = 10) treated with: G1, low-torque handpiece; G2, high-torque handpiece; and G3, Er: YAG laser (2.94 mu m at 250 mJ/4 Hz), all with water cooling. The temperature increases were recorded with a computer linked to the thermocouples. Results The data were submitted to ANOVA and Tukey statistical test. The average temperature rises were: 1.92 +/- 0.80 degrees C for G1, 1.34 +/- 0.86 degrees C for G2, and 0.75 +/- 0.39 degrees C for G3. There were significant statistical differences among the groups (p = 0.095). All the groups tested did not have a change of temperature that exceeds the threshold of 5.5 degrees C. Conclusion Temperature response to the low and high torque handpieces seemed to be similar, however the Er: YAG laser generated a lower temperature rise.