Rotary voice-coil motors from computer hard disk drives make excellent mechanical shutters for light beams. However, the complexity of the necessary electronic driving circuit can hinder their application. A new design is presented here, using a single integrated circuit originally intended for controlling dc motors. A digital input signal switches a unipolar power supply bidirectionally throug...

Abstract Ducted wind turbines (DWTs) can take the advantage of ground effect (GE) when installed close to urban areas. To this aim, a parametric study investigate aerodynamic performance DWTs in relation three different distances are investigated. The flow around commercial DWT model using simplified duct actuator disc (AD) based on Reynolds Averaged Navier-Stokes (RANS) equations is performed....

abstract   background: far lateral discal herniation is an uncommon disorder and is difficult to assess by physical examination alone. this study is designed to define clinical and epidemiological findings and to establish the indications of surgical and medical treatment for flldh.   methods: between 2000 and 2005, a total of 2035 patients with lumbar disc herniation underwent surgical discect...

To analyse the sensitivity of blade geometry and airfoil characteristics on the prediction of performance characteristics of wind farms, large-eddy simulations using an actuator disc (ACD) method are performed for three different blade/airfoil configurations. The aim of the study is to determine how the mean characteristics of wake flow, mean power production and thrust depend on the choice of ...

This paper addresses the experimental identification of a servo actuator which is used in many industrial applications. Because the system consisted of electrical and mechanical components, the behavior of the system was nonlinear. In addition, the under load behavior of this servo was different. The load torque was considered as the input and a two input-one output model was presented for t...

conclusions in this study, we found that in spite of previous beliefs, discopathies were not common etiologies of lbp. thus, even in patients with proven ldh by imaging studies, the physician should perform a thorough evaluation for other causes of lbp to avoid unnecessary lumbar surgeries. results in our study, among 1250 patients with proven ldh by mri, 500 patients (40%) had chronic lbp and ...

We have studied a stacked-type electrostatic actuator by folding two ribbon electrodes in an alternate configuration. The energy efficiency of this type of actuator was investigated using the thick-electrode-part actuator and triangle-shaped actuator. The maximum energy efficiency levels were 30–40% for the thick-electrode-part actuator and 40–50% for the triangle-shaped actuator.