Search results for "Torque"

Dynamics of a Ferromagnetic Particle Levitated Over a Superconductor

2018

Under conditions where the angular momentum of a ferromagnetic particle is dominated by intrinsic spin, applied torque is predicted to cause gyroscopic precession of the particle. If the particle is sufficiently isolated from the environment, a measurement of spin precession can potentially yield sensitivity to torque beyond the standard quantum limit. Levitation of a micron-scale ferromagnetic particle above a superconductor is a possible method of near frictionless suspension enabling observation of ferromagnetic particle precession and ultrasensitive torque measurements. We experimentally investigate the dynamics of a micron-scale ferromagnetic particle levitated above a superconducting …

Hydrodynamics with spin in bacterial suspensions

2016

We describe a new kind of self-propelling motion of bacteria based on the cooperative action of rotating flagella on the surface of bacteria. Describing the ensemble of rotating flagella in the framework of the hydrodynamics with spin the reciprocal theorem of Stokesian hydrodynamics is generalized accordingly. The velocity of the self-propulsion is expressed in terms of the characteristics of the vector field of flagella orientation and it is shown that unusually high velocities of \textit{Thiovulum majus} bacteria may be explained by the cooperative action of the rotating flagella. The expressions obtained enable us to estimate the torque created by the rotary motors of the bacterium and …

Le cimetière du second âge du Fer du « Bas des Aouches » à Gisy-les-Nobles (Yonne) : découvertes anciennes et fouilles modernes

2015

Die Untersuchung betrifft die Metallfunde einer zufällig am Ende des 19. Jahrhunderts entdeckten Nekropolesowie die Reste von Körpergräbern, die 1978 am gleichen Fundplatz ausgegraben wurden. Trotz der Dürftigkeit der Informationenermöglichen die Funde eine Unterteilung in chronologische Phasen, die vom zweiten Viertel des 5. Jh. v. Chr. bis zu den letztenJahrzehnten des 3. Jh. v. Chr. reichen und den bereits bekannten Daten des regionalen Bestattungswesens entsprechen

Design and Simulation of a Vision-Based Automatic Trout Fish-Processing Robot

2021

Today, industrial automation is being applied in a wide range of fields. The initial modeling of robots and mechanical systems together with simulation results in optimal systems. In this study, the designed system is simulated to obtain the required velocities, accelerations and torques of the actuating arms in a vision-based automatic system. Due to the slippery skin of fish and the low friction coefficient, it is not easy to design an optimal tool to handle fish. Since the fish-processing operation is undertaken step by step and provides fish stability, it is essential that the gripper enables different processing operations along the system. The proposed system performs belly-cutting, b…

A novel correction method for a low cost sensorless control system of IPMSM electrical drives

2008

In this paper a novel correction method for sensorless Field Oriented Control System of Brushless internal Permanent Magnet Electrical Drives is introduced discussed and experimentally validated. The novelty of this control system is the estimation of rotor speed and angular position is based on the back electromotive force space vector determination, without the aid of voltage probes. Actual voltage signals needed for estimation are replaced with the reference ones given by the current controller. This choice obviously introduces an error that have been vanished by means of a new compensating function or with the aid of data coming from experimental tests. Experimental verifications of the…

On the Effect of Slotted Blades on Savonius Wind Generator Performances by CFD Analysis

2012

In this paper a new bucket configuration for Savonius wind generator is proposed. With the aim to increase the effect of the overlap ratio RS on the wind turbine performances and to increase the amount of lift force able to produce torque and power, slotted blades are investigated by means of the Computational Fluid Dynamics analysis. The numerical analyses are performed by Comsol Multiphysics® and the results obtained for a Savonius wind turbine with overlap only are compared to numerical and experimental benchmarks. Parametric analyses are performed, for fixed overlap ratio, by varying the slot angle β and the results show that for low angle β the Savonius rotor exploits improved performa…

Early kinetics of Torque Teno virus DNA load and BK polyomavirus viremia after kidney transplantation

2019

The role of the effect of manufacturing tolerances on a tubular linear ferrite motor

2015

Electric machines are often designed without considering workmanship and materials tolerances. Their manufacturing process involves a series of steps, starting with raw materials and ending with the machine assembly. In each of these steps occur deviations due, for instance, to mistakes in positioning tools or to the tolerances in the electrical and magnetic characteristics of the materials. These deviations may cause unwanted parasitic effects such as torque ripple, losses or acoustic noise. Such effects have to be considered especially in machines used in industrial drives for high performance applications. Moreover the tolerances in the magnetic materials have a considerable effect on th…

Modeling of Friction Losses in Offshore Knuckle Boom Crane Winch System

2018

This paper presents a method for friction modeling in a hydraulically actuated multi motor winch system of an offshore knuckle boom crane. The method is based on a combination of a model of the variable displacement axial piston motor based on measurements from the sub supplier, and combined with a model of the remaining friction loss obtained from measurements on the full system.

Control Strategy for Induction Motor Drives Based on Decoupling Techniques

1989

Abstract In this work a new closed loop, synchronous microprocessor-based controller is proposed for field oriented controlled induction motor drives, using a PWM voltage source inverter. This controller is based on a non linear state feedback compensator which gives decoupling of both rotor current and rotor flux, and direct and inquadrature components of the stator current vector. The compensator has a linearizing effect on the synchronous model of the electromagnetic circuit of the motor. It follows that the control laws can be obtained using optimal control techniques for linear systems. The controller in question gives directly the conduction sequences of the inverter supplying the ind…