Step Motors
Mostrando 13-24 de 30 artigos, teses e dissertações.
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13. Oclusor ativo implantavel para colostomias : prototipo
: Aiming to improve the quality of life of colostomates, the prototype of na Active Implantable Colostomy Occluder was built. The fundamental idea is to reproduce the natural sphincter?s action by using a construction band placed around the stoma and pulled by a step motor. The active element of the prototype is a step motor and its torque is powered by thre
Publicado em: 1997
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14. DEVELOPMENT AND CONSTRUCTION OF A PROTOTYPE OF AN AUTOMATIC MOLD READER / DESENVOLVIMENTO E CONSTRUÇÃO DE UM PROTÓTIPO DE UMA LEITORA AUTOMÁTICA DE MOLDES
Confection companies are using more and more equipments to improve their productions. Not only concerned on the amount of products, but also for higher quality. Especially in process before fabric cutting, many of these machines are automatic. The reason for this work is to develop an equipment to capture images from molds, using only one optic sensor. It mu
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/01/1995
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15. Locomotivas de C.A : uma analise harmonica da corrente
AC thyristor controlled electric traction became very usual around the world. Thyristors provide good control performance but they always cause problems to the traction electric system. Overvoltages may arise in the contact line feeding the locomotive and also harmonics generated in the thyristors may affected the grid to which the whole system is connected.
Publicado em: 1993
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16. Minitomografo de raio-X e raio-gama computadorizado para aplicações multidisciplinares
The main result of this thesis is the development, implementation and use of an X-ray and y-ray computerized minitomography scanner with possible applications in multidisciplinary fields particularly in soil physics. The hardware is basically a mechanical table with two step motors, one for rotation and another for translation motions, radioactive,source, co
Publicado em: 1987
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17. Study of kinetic and formation of aggregates in ionic crystals using two photon absorption technique. / Estudo da cinética e formação de agregados em cristais iônicos pela técnica de absorção de dois fótons.
In this work we realize the study of the Kinetic and formation of precipitates in ionic crystals doped with divalent impurities by the TPA (two photon absorption) spectroscopy technique. We analyze the formation of the aggregates in crystals annealed at temperatures of 50 and 250°C. We measured the TPA of the transition 4f7 → 4f7 of the Eu2+, which
Publicado em: 1985
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18. Molecular motors: thermodynamics and the random walk.
The biochemical cycle of a molecular motor provides the essential link between its thermodynamics and kinetics. The thermodynamics of the cycle determine the motor's ability to perform mechanical work, whilst the kinetics of the cycle govern its stochastic behaviour. We concentrate here on tightly coupled, processive molecular motors, such as kinesin and myo
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19. Monte Carlo modeling of single-molecule cytoplasmic dynein
Molecular motors are responsible for active transport and organization in the cell, underlying an enormous number of crucial biological processes. Dynein is more complicated in its structure and function than other motors. Recent experiments have found that, unlike other motors, dynein can take different size steps along microtubules depending on load and AT
National Academy of Sciences.
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20. Active Nucleosome Displacement: A Theoretical Approach
Three-quarters of eukaryotic DNA are wrapped around protein cylinders forming so-called nucleosomes that block the access to the genetic information. Nucleosomes need therefore to be repositioned, either passively (by thermal fluctuations) or actively (by molecular motors). Here we introduce a theoretical model that allows us to study the interplay between a
The Biophysical Society.
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21. Kinesin's second step
We have identified dimeric kinesin mutants that become stalled on the microtubule after one ATP turnover, unable to bind and hydrolyze ATP at their second site. We have used these mutants to determine the regulatory signal that allows ATP to bind to the forward head, such that processive movement can continue. The results show that phosphate release occurs f
National Academy of Sciences.
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22. Force generation, work, and coupling in molecular motors.
A mechanism is proposed for molecular motors in which force is generated by a protein conformational change driven by binding energy (in muscle, that of myosin with actin as well as with ATP, ADP, or Pi). Work, the product of the force generated by one myosin or kinesin molecule (F) and the distance over which it acts (d), is a function of a ratio of dissoci
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23. Identification of a site of ATP requirement for signal processing in bacterial chemotaxis.
In Escherichia coli and Salmonella typhimurium, ATP is required for chemotaxis and for a normal probability of clockwise rotation of the flagellar motors, in addition to the requirement for S-adenosylmethionine (J. Shioi, R. J. Galloway, M. Niwano, R. E. Chinnock, and B. L. Taylor, J. Biol. Chem. 257:7969-7975, 1982). The site of the ATP requirement was inve
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24. Association of a Nonmuscle Myosin II with Axoplasmic Organelles
Association of motor proteins with organelles is required for the motors to mediate transport. Because axoplasmic organelles move on actin filaments, they must have associated actin-based motors, most likely members of the myosin superfamily. To gain a better understanding of the roles of myosins in the axon we used the giant axon of the squid, a powerful mo
The American Society for Cell Biology.