A dc servosystem including an ac motor

Closed loop servosystem for variable speed tape recorders on board spacecraf

Slow-speed drives for miniature devices

Hysteresis motor minimizes motor torque variations during shaft revolution when operated at high frequency and with a sinusoidal motor current. Motor speed is stabilized by a feedback servo

Wholes and parts of things

El estudio introduce un conjunto de hipótesis que intentan explicar la relación entre las partes y los todos de las cosas. Para ello se desarrollan doce hipótesis que elaboran los conceptos de cosa, interrelación, todo, parte, todo orgánico, holon, parthol, nivel, arquía,cambio y permanencia, tiempo y causa. La exposición se articula conforme a la expansión interna de dichos conceptos

An Interpretation of the Nature of Presence and Some Implications of the Interpretation.

Ph.D.PhilosophyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/156624/1/0000329.pd

Organicism: A more holistic explanation

Cuando encontramos nuestra teoría de la naturaleza de la existencia al reconocer que organización y energía, son dos aspectos universales de la naturaleza de la existencia y comunes a toda existencia. Ello es la base las explicaciones de la naturaleza de las cosas. Organicismo es así otra propuesta que intenta proporcionar una base para "la unidad de todas las Ciencias

Dynamic Pattern Formation in Electron-Beam-Induced Etching

© 2015 American Physical Society. We report highly ordered topographic patterns that form on the surface of diamond, span multiple length scales, and have a symmetry controlled by the precursor gas species used in electron-beam-induced etching (EBIE). The pattern formation dynamics reveals an etch rate anisotropy and an electron energy transfer pathway that is overlooked by existing EBIE models. We, therefore, modify established theory such that it explains our results and remains universally applicable to EBIE. The patterns can be exploited in controlled wetting, optical structuring, and other emerging applications that require nano- and microscale surface texturing of a wide band-gap material

Localized probing of gas molecule adsorption energies and desorption attempt frequencies

© 2015 American Chemical Society. Gas-mediated electron beam induced etching (EBIE) and deposition (EBID) can be used to measure activation energies that are interpreted as the adsorption energies of surface-adsorbed precursor molecules. However, the measured quantities often disagree with adsorption energies measured by conventional analysis techniques such as thermally programmed desorption and have anomalous dependencies on parameters such as the electron beam current used to perform EBID. Here, we use the theory of EBIE and EBID rate kinetics to explain this behavior and identify conditions under which the activation energies and the associated pre-exponential factors correspond to gas molecule adsorption energies and desorption attempt frequencies, respectively. Under these conditions, EBIE and EBID can be used as robust, nanoscale techniques for the analysis of adsorbates

Does primary brachial plexus surgery alter palliative tendon transfer surgery outcomes in children with obstetric paralysis?

<p>Abstract</p> <p>Background</p> <p>The surgical management of obstetrical brachial plexus palsy can generally be divided into two groups; early reconstructions in which the plexus or affected nerves are addressed and late or palliative reconstructions in which the residual deformities are addressed. Tendon transfers are the mainstay of palliative surgery. Occasionally, surgeons are required to utilise already denervated and subsequently reinnervated muscles as motors. This study aimed to compare the outcomes of tendon transfers for residual shoulder dysfunction in patients who had undergone early nerve surgery to the outcomes in patients who had not.</p> <p>Methods</p> <p>A total of 91 patients with obstetric paralysis-related shoulder abduction and external rotation deficits who underwent a modified Hoffer transfer of the latissimus dorsi/teres major to the greater tubercle of the humerus tendon between 2002 and 2009 were retrospectively analysed. The patients who had undergone neural surgery during infancy were compared to those who had not in terms of their preoperative and postoperative shoulder abduction and external rotation active ranges of motion.</p> <p>Results</p> <p>In the early surgery groups, only the postoperative external rotation angles showed statistically significant differences (25 degrees and 75 degrees for total and upper type palsies, respectively). Within the palliative surgery-only groups, there were no significant differences between the preoperative and postoperative abduction and external rotation angles. The significant differences between the early surgery groups and the palliative surgery groups with total palsy during the preoperative period diminished postoperatively (p < 0.05 and p > 0.05, respectively) for abduction but not for external rotation. Within the upper type palsy groups, there were no significant differences between the preoperative and postoperative abduction and external rotation angles.</p> <p>Conclusions</p> <p>In this study, it was found that in patients with total paralysis, satisfactory shoulder abduction values can be achieved with tendon transfers regardless of a previous history of neural surgery even if the preoperative values differ.</p