Front Of Cylinder Research Articles

Anti-noise-electret pick-up with an electret

A noise canceling pickup with an electret is provided with a cylinder body having a front cover and a rear cover, said front cover is provided with sound passing holes, said cylinder body is provided with an oscillating membrane of the electret, a back electrode sheet and a back electrode base, wherein said cylinder body is composed of a front cylinder body and a rear cylinder body, said oscillating membrane is provided into said front cylinder body, said rear cover of said cylinder body is provided with at least one sound passing hole, and said rear cover is provided with electric elements therein. With the arrangement according to the present invention, the distance between the opposite front and rear sound passing holes can be made smaller. The noise canceling pickup with an electret, can be used in the higher frequency band and in a wide frequency range to cancel the noises more effectively.

Deceleration of high-energy matrix-assisted laser desorption/ionization ions in an open cell for Fourier transform ion cyclotron resonance mass spectrometry.

A new method of ion deceleration in a Fourier transform ion cyclotron resonance (FTICR) open cell is described that improves the performance of FTICR-MS instruments equipped with an internal source for laser desorption/ionization. Ion deceleration occurs in the front trapping cylinder of an open cylindrical cell. Decelerating voltages up to 100 V can be applied for 10-500 micros to the front cylinder during ion introduction. The deceleration field is uniformly distributed along the cylinder length giving a "smooth" deceleration, which means that the deceleration is effective over a large time interval and a large m/z range. This results in improved trapping efficiency of high-energy ions. We demonstrate efficient trapping of high (m/z 66 kDa) mass ions and the possibility to reduce the width of the kinetic energy distribution of MALDI ions with this arrangement.

さく孔過程に及ぼすスラストの影響 計算機によるさく岩機のさく孔過程のシミュレーション（第２報）

A drilling model was previously proposed by Okubo and Nishimatsu (1991), and a computer program which had capability to simulate continuous drilling-process was also developed bythem. The model which consists of a drill-body, a piston, a rod and a bit was analyzed based on the one-dimensional stress-wave theory. A force-penetration curve with hysteresis was assumed for bit/rock interface.In this study, comprehensive simulation for a heavy drifter of 150 kg-class was carried out. Special care was taken to clarify the effect of thrust on rock-drilling performance such as penetration rate, piston stroke, piston velocity, elastic wave in rod. Calculation was performed under more than two-thousand conditions changing thrust, bit/rock interface parameters and attenuation rate on drill/rod interface.An appropriate thrust, Fth_apl, was proposed as follows; Fth-apl≅Aback·Pback-Afront·Pfront, Where ‘A’ denotes effective cross-sectional area, and ‘P’ pressure. Subscripts ‘back’ and ‘front’ indicate back and front cylinders, respectively.

Study of the sandwiched piezoelectric ultrasonic torsional transducer

The sandwiched piezoelectric ultrasonic torsional transducer was studied. The transducer consists of front and back metal cylinders, and coaxially segmented, tangentially polarized, piezoelectric ceramic tubes. The torsional vibration of the tangentially polarized piezoelectric ceramic slender tube was studied first and its electromechanical equivalent circuit was derived. Based on the network theory and the electromechanical equivalent circuit, the torsional vibration of the piezoelectric ceramic cylinder, formed by stacking a number of identical short piezoelectric ceramic rings, was analysed and the electromechanical equivalent circuit of the piezoelectric ceramic stack in torsional vibration was developed. Finally, the sandwiched ultrasonic torsional transducer was studied and resonance frequency equations were derived which can be used to design and calculate the torsional transducers for different applications.

Surface Injection Effect on Mass Transfer From a Cylinder in Crossflow: A Simulation of Film Cooling in the Leading Edge Region of a Turbine Blade

A naphthalene sublimation technique is used to study the effect of surface injection on the mass (heat) transfer from a circular cylinder in crossflow. Using a heat/mass transfer analogy the results can be used to predict film cooling effects in the leading edge region of a turbine blade. Air injection through one row of circular holes is employed in the stagnation region of the cylinder. Streamwise and spanwise injection inclinations are studied separately, and the effects of blowing rate and injection location relative to the cylinder front stagnation line are investigated. Streamwise injection produces significant mass transfer increases downstream of the injection holes, but a relatively small increase is observed between holes, normal to the injection direction. The mass transfer distribution, measured with spanwise injection through holes located near the cylinder front stagnation line, is extremely sensitive to small changes in the injection hole location relative to stagnation. When the centers of the spanwise injection holes are located 5 deg or more from the stagnation line, the holes lie entirely on one side of the stagnation line and the injection affects the mass transfer only on that side of the cylinder, approaching the pattern observed with streamwise injection.

Fluid Forced acting on Two Circuler Cylinders in Tandem Arrangement

Experimental investigatins on the fluid forces acting on two circuler cylinders in tandem arrangement were carried out. The Reynolds number and the distance between the cylinders were varied in the range 1×104<Re<8×104 and 1≤1/d≤6. As a results of systematic investigation on drag and lift forces measured at the same time, fluctuation of fluid forces are divided into four patterns according to their charactristics. It was found that the intermittent changes of time-mean drag and intensity of fluctuating drag and lift occure in the range 1/d=3-4 at front cylinder and 1/d=2.5-4 at rear. This discotinuous changes of fluid forces is caused by the abrupt change from one stable flow pattern to another. The results were summarized in several figures from which one can obtain the timemean and the intensity of fluctuating drag and lift and the Strouhal number.

The Secondary Flow about a Circular Cylinder Mounted Normal to a Flat Plate

Three-dimensional steady incompressible viscous flows about a circular cylinder being mounted with its axis normal to a flat plate were studied numerically. First a finite-difference method using the equations in terms of the pressure p, the velocity u and the vorticity ξ was proposed. In the method the cells in an orthogonal curvilinear coordinate system are used, which consists of the equi-potential lines and the streamlines for a tow-dimensional potential flow past a circular cylinder in a uniform flow. It is convenient to use such coordinates to prescribe the initial and outer boundary conditions and to show the secondary flows. Then the flow patterns for the Reynolds numbers 100 and 500 were calculated. The flow separation and the horseshoe vortex at the front of cylinder, anothervotex generating near the side corner, and the shearing stress at the flat plate and the cylinder walls were discussed.

A Cloud Chamber of Light Weight for Balloon Flights

Some constructional details of cloud chambers used for balloon flights are described. Details are given on the fabrication of transparent plastic front walls and cylinders for the cloud chambers. A relatively large number of bicycle spokes is used for holding the chamber together, thus distributing material stresses, enabling one to make the aluminum parts of the cloud chamber quite light. The back and front walls of the cloud chambers are somewhat spherically curved, resulting in considerable reduction of material thicknesses. By the same means a piece of slightly curved metal gauze is sufficient to limit the motion of the rubber diaphragm in the compressed position. A mechanism used for adjusting expansion ratios can be removed before a balloon flight. Gas and liquid can be inserted through bicycle valves. The cloud chambers are 12 inches in diameter, 3½ inches deep, and weigh approximately 6 pounds.