Síntese e funcionalização de superfícies de óxido de ferro superparamagnéticos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Síntese e caractrização de nanopartículas magnéticas do tipo caroço@casca de 'CO'@'PD' com propriedades para aplicações tecnológicas

Pós-graduação em Química - IQ

Nanopartículas aciculares metálicas de 'Fe', 'Fe''Co', 'Fe''TR' e 'Fe''Co''TR'('TR'='La'-'Tb') para tecnologia avançada de gravação magnética

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

Dinâmica do aparelho locomotor em sujeitos amputados e não-amputados do membro inferior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação da cintilação ionosférica no Brasil e seus efeitos no posicionamento por GNSS

Pós-graduação em Ciências Cartográficas - FCT

Indicadores biomecânicos do risco de quedas em marcha com duplas tarefas e a influência do treinamento de equilíbrio com haste vibratória: diferenças entre idosos caidores e não caidores

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

Processamento e propriedades magnéticas de manganitas multiferróicas = Mise en forme et propriétés magnétiques de manganites multiferróïques

Pós-graduação em Ciência e Tecnologia de Materiais - FC

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.

A study of low velocities regions near the Roche lobe during the gas giant planets formation

In this paper were studied regions close to the Roche lobe of a planet like Jupiter, in order to find regions with low velocities. We simulated a two dimensional and non-self-gravitating disk, where tidal and viscous torques are considered, using the hydrodynamic numerical integrator FARGO 2D. As stated earlier we are interested in find low velocities regions for in future works study the possibility of satellites formation in these regions.

Estados de impurezas em semicondutores e nanoesetruturas sob campos externos

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Desenvolvimento, otimização e caracterização física de um novo sistema multi-sensores de Biosusceptometria de Corrente Alternada (BAC) para obtenção de imagens biomagnéticas

A novel AC Biosusceptometry (ACB) system with thirteen sensors it was implemented and characterized in vitro using magnetic phantoms. The system presenting coils in a coaxial arrangement with one pair of excitation coil outside and thirteen pairs of detection coils inside. A first-order gradiometric configuration was utilized for optimal detection of magnetic signals. Several physical parameters such as baseline, number of turns, excitation field and diameters were studied for improvement of the signal/noise ratio. This system exhibits an enhanced sensitivity and spatial resolution, due to the higher density of sensors/area. In the future those characteristics will turn possible to obtain images of magnetic marker or tracer in the gastrointestinal tract focusing on physiological and pharmaceutical studies. ACB emerged due to its interesting nature, noninvasiveness and low cost to investigate gastrointestinal parameters and this system can contribute for more accurate interpretation of biomedical signals and images

Estudo das propriedades elétricas do cobre e alumínio; sobre a força magnética em um imã caindo dentro de um tubo

Magnetic fields can be produced by natural magnets, artificial magnets, and by circulating electric currents in wires and solenoids. An interesting experiment to observe the interaction between the magnetic field and free charges in a conductor, a magnet falling inside a tube made of conductive materials. The slowing down of the magnet by the appearance of a field in the opposite direction to the original one (Lenz's Law) is function the number of free electrons in the conductor and the electrical properties of this. Based on this, the objective of this study is to analyze the relationship between the electrical properties of conductors, copper and aluminum, with magnetic force on a neodymium magnet-iron-boron magnet falling inside a copper tube and aluminum, positioned vertically. In performing this experiment, we observed that it is a demonstration of Lenz-Faraday’s Law

Satélites estabilizados por rotação e torque de radiação solar direta

The aims of this work are to analyze the direct solar radiation pressure torque (TPRS) in the rotational motion of spin-stabilized artificial satellites, to numerically implement these solutions and to compare the results with real data of the Brazilian Satellite Data Collection – SCD1 and SCD2, supplied by INPE. The mathematical model for this torque is determined for a cylindrical satellite, and the components of this torque are determined in a fixed system in the satellite. An analytical solution for the spin motion equations is proposed, in which TPRSD does not affect the spin velocity of the satellite. Two approaches are adopted in the numerical implementation of the developed theory: the first one considers the proposed theory and the second introduces a variation in the spin velocity based on its real variation. The results obtained indicate that the solar radiation pressure torque has little influence in the right ascension and declination axis of rotation due to the small dimension of the satellite and altitude in which it is found. To better validate the application of the presented theory, the angular deviation of the spin axis and solar aspect angle were also analyzed. The comparison of the results of the approaches conducted with real data show good precision in the theory, which can be applied in the prediction of the rotational motion of the spin-stabilized artificial satellites, when others external torques are considered besides the direct solar radiation pressure torque

Análise da influência do torque de montagem na resistência de parafusos de fixação

Whereas the assembly torque calculation has great importance on efficiency and life of bolts, the objective of this study was to analyze the combined stresses during assembly, the friction coefficient, compare the rupture torque results with the indicated torques by standards and to present a new torque method without the stress combination (shear stress and normal stresses). For this study were carried eighteen tests with different diameters and materials, this bolts were undergoing five ranges torque until the breaking torque. With the experimental rupture torque values for each test and with the bolt quality certificate was possible to calculate the friction coefficient so compared with the theory. Another comparison was the experimental rupture torque with assembly torque indicated by NBR-8800 and ASME-PCC. The main conclusion are related to combined stress, because for this factor can fail at the assembly time, so for in some cases must use the tensioning method, because in this method won't be present torsional stresses

Estudo experimental da indução magnética

This work will discuss how magnetic fields can be produced, either generated by magnets, natural, artificial, or even by an electric current going through a wire, as discovered by Oersted. Besides the theoretical content, experimental studies on magnetic induction and on the Laws of Faraday and Lenz will be performed. In the Magnetic Induction experiment, the electromotive force generated by varying the flow of the field B in a solenoid, depending on the variation of the current intensity and frequency associated with it will be measured; the experiment on the Laws of Faraday and Lenz the electromotive force produced by the relative movement of the magnet in relation to a coil. Thus, this study experimental verification of magnetic induction using solenoids and magnets; analysis of magnetic induction by Faraday's Law and Lenz's Law