Luz e sombra, mostrar e esconder: os efeitos de sentido e as estratégias da imagem fotográfica em magnum in motion

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação vestibular em adolescentes com cinetose

Pós-graduação em Pediatria - FMB

Desenvolvimento de um sistema bidimensional de monitoração da saída de nadadores

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Suspensões de veículos - Um estudo de caso

Pós-graduação em Engenharia Mecânica - FEG

Scalar source in circular motion interacting with massive klein-gordon field in Minkowski spacetime

We analyze the scalar radiation emitted by a source in uniform circular motion in Minkowski spacetime interacting with a massive Klein-Gordon field. We assume the source rotating around a central object due to a Newtonian force. By considering the canonical quantization of this field, we use perturbation theory to compute the radiation emitted at the tree level. Regarding the initial state of the field as being the Minkowski vacuum, we compute the emission amplitude for the rotating source, assuming it as being minimally coupled to the massive Klein-Gordon field. We then compute the power emitted by the swirling source as a function of its angular velocity, as measured by asymptotic static observers.

Measurement of higher-order harmonic azimuthal anisotropy in PbPb collisions at root s(NN)=2.76 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tm-afm nonlinear motion control with robustness analysis to parametric errors in the control signal determination

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Semi-analytical study of the rotational motion stability of artificial satellites using quaternions

This study at aims performing the stability analysis of the rotational motion to artificial satellites using quaternions to describe the satellite attitude (orientation on the space). In the system of rotational motion equations, which is composed by four kinematic equations of the quaternions and by the three Euler equations in terms of the rotational spin components. The influence of the gravity gradient and the direct solar radiation pressure torques have been considered. Equilibrium points were obtained through numerical simulations using the softwares Matlab and Octave, which are then analyzed by the Routh-Hurwitz Stability Criterion.

Do people with recurrent back pain constrain spinal motion during seated horizontal and downward reaching?

Background: Although the effect of symptomatic back pain on functional movement has been investigated, changes to spinal movement patterns in essentially pain-free people with a history of recurrent back pain are largely unreported. Reaching activities, important for everyday and occupational function, often present problems to such people, but have not been considered in this population. The purpose of this study was to compare the amplitude and timing of spinal and hip motions during two, seated reaching activities in people with and without a history of recurrent low back pain (RLBP).Methods: Spinal and hip motions during reaching downward and across the body, in both directions, were tracked using electromagnetic sensors. Analyses were conducted to explore the amplitudes, velocities and timings of 3D segmental movements and to compare controls with subjects with recurrent, but asymptomatic lumbar or lumbosacral pain.Findings: We detected significant differences in the amplitude and timing of movement in the lower thoracic region, with the RLBP group restricting movement and demonstrating compensatory increased motion at the hip. The lumbar region displayed no significant between-group differences. The order in which the spinal segments achieved peak velocity in cross-reaching was reversed in RLBP compared to controls, with lumbar motion leading in controls and lagging in RLBP.Interpretation: Subjects with a history of RLBP show a number of altered kinematic features during reaching activities which are not related to the presence or intensity of pain, but which suggest adaptive changes to movement control. (C) 2013 Elsevier Ltd. All rights reserved.

Effects of physical exercise on articular range of motion of the lower limb in the Parkinson's disease individuals

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A study of the errors of the averaged models in the restricted three-body problem in a short time scale

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Massive spin-2 particles via embedment of the Fierz-Pauli equations of motion

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Computer graphics applied to anatomy: a study of two bio-cad modeling methods on finite element analysis of human edentulous hemi-mandible

Modeling is a step to perform a finite element analysis. Different methods of model construction are reported in literature, as the Bio-CAD modeling. The purpose of this study was to perform a model evaluation and application using two methods of Bio-CAD modeling from human edentulous hemi-mandible on the finite element analysis. From CT scans of dried human skull was reconstructed a stereolithographic model. Two methods of modeling were performed: STL conversion approach (Model 1) associated to STL simplification and reverse engineering approach (Model 2). For finite element analysis was used the action of lateral pterygoid muscle as loading condition to assess total displacement (D), equivalent von-Mises stress (VM) and maximum principal stress (MP). Two models presented differences on the geometry regarding surface number (1834 (model 1); 282 (model 2)). Were observed differences in finite element mesh regarding element number (30428 nodes/16683 elements (model 1); 15801 nodes/8410 elements (model 2). D, VM and MP stress areas presented similar distribution in two models. The values were different regarding maximum and minimum values of D (ranging 0-0.511 mm (model 1) and 0-0.544 mm (model 2), VM stress (6.36E-04-11.4 MPa (model 1) and 2.15E-04-14.7 MPa (model 2) and MP stress (-1.43-9.14 MPa (model 1) and -1.2-11.6 MPa (model 2). From two methods of Bio-CAD modeling, the reverse engineering presented better anatomical representation compared to the STL conversion approach. The models presented differences in the finite element mesh, total displacement and stress distribution.

A squeezed state holomorphic phase space representation of equations of motion

A mapping scheme is presented which takes quantum operators associated to bosonic degrees of freedom into complex phase space integral kernel representatives. The procedure consists of using the Schrödinger squeezed state as the starting point for the construction of the integral mapping kernel which, due to its inherent structure, is suited for the description of second quantized operators. Products and commutators of operators have their representatives explicitly written which reveal new details when compared to the usual q-p phase space description. The classical limit of the equations of motion for the canonical pair q-p is discussed in connection with the effect of squeezing the quantum phase space cellular structure. © 1993.

Preventing chaotic motion in tapping-mode atomic force microscope

During the last 30 years the Atomic Force Microscopy became the most powerful tool for surface probing in atomic scale. The Tapping-Mode Atomic Force Microscope is used to generate high quality accurate images of the samples surface. However, in this mode of operation the microcantilever frequently presents chaotic motion due to the nonlinear characteristics of the tip-sample forces interactions, degrading the image quality. This kind of irregular motion must be avoided by the control system. In this work, the tip-sample interaction is modelled considering the Lennard-Jones potentials and the two-term Galerkin aproximation. Additionally, the State Dependent Ricatti Equation and Time-Delayed Feedback Control techniques are used in order to force the Tapping-Mode Atomic Force Microscope system motion to a periodic orbit, preventing the microcantilever chaotic motion