Stability and control of rotors at high advance ratio are considered. Stability of teetering, articulated, and gimbaled hub types is considered with a simple flapping blade analysis. Rotor control in autorotation for teetering and articulated hub types is examined in more detail for a compound helicopter (rotor and fixed wing) using the comprehensive analysis CAMRAD II. Autorotation is found to...

BACKGROUND AND PURPOSE Image quality and diagnostic reliability of T2-weighted MR images of the cervical spine are often impaired by several kinds of artifacts, even in cooperative patients. The aim of this study was to evaluate if BLADE sequences might solve these problems in a routine patient collective. MATERIALS AND METHODS TSE and BLADE sequences were compared in 60 patients for T2-weigh...

Background: Laryngoscopy and tracheal intubation are known to have profound cardiovascular effects. The Callander modification of Macintosh blade is associated with greater field of laryngoscopic view and decreased risk of dental contact. The purpose of this study was to compare the hemodynamic responses to laryngoscopy and tracheal intubation according to the degree of difficult airway, and to...

Instrumental evaluations (e.g. Dobrzynski, InterNoise 90) showed that propeller noise can be reduced by asymmetrical blade spacing. Compared to conventional propellers with 6 blades and symmetrical spacing of 60°, propellers with asymmetric spacing of 15° produce about 3 dB(A) less level, in particular for high helical blade tip Mach numbers HBTMN. Since the aerodynamic propeller performance is...

BACKGROUND The shape of a laryngoscope blade affects the exposition of the larynx. This study evaluates and compares some rigid and levering blade designs based on previous investigative X-ray laryngoscopic studies. METHODS Five rigid laryngoscope blades (Miller #3, Standard Macintosh #3, Classical Macintosh #4 and English-Macintosh #3 and #4) and two levering laryngoscope blades (McCoy in ne...

PURPOSE In magnetic resonance imaging of the brain, BLADE is used to compensate for head motion. The technique focuses mainly on acquisition of T(2)-weighted or contrast-enhanced T(1)-weighted images in adults; its utility for nonenhanced T(1)-weighted imaging in children is not well established. We compared the quality of T(1)-weighted fluid-attenuated inversion recovery brain imaging with BLA...

BACKGROUND Plastic single-use laryngoscope blades are inexpensive and carry a lower risk of infection compared with metal reusable blades, but their efficiency during rapid sequence induction remains a matter of debate. The authors therefore compared plastic and metal blades during rapid sequence induction in a prospective randomized trial. METHODS Two hundred eighty-four adult patients under...

This study investigated the mechanical properties of a new rectangular compaction blade and compared this blade with other types of nail. Three types of nail were tested: the Magnum lag screw (Robert Reid Inc, Tokyo, Japan), proximal femoral nail, and Magnum Fid blade (Robert Reid Inc). The nails were inserted into solid rigid polyurethane foam, and the torsional moments were loaded with an Ins...

This paper is part of a study to develop robots for farming. As such power requirement to operate equipment attach to such robots become an important factor. Soil-tool interaction plays major role in power consumption, thus predicting accurately the forces which act on the blade during the farming is very important for optimal designing of farm equipment. In this paper, a finite element investi...

In this paper a 3-D finite element (FE) investigation of soil-blade interaction is described. The effects of blade’s shape and rake angle are examined both numerically and experimentally. The soil is considered as an elastic-plastic granular material with non-associated Drucker-Prager material model. Contact elements with different properties are used to mimic soil-blade sliding and soil-soil c...