• Title, Summary, Keyword: Cylinder contact

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NOx removal in cylinder type reactor and Packed-bed type reactor (원통형과 packed-bed형 반응기에서 NOx제거특성)

  • 박재윤;박상현;이경호;하상태;송원섭;황보국
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.499-502
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    • 2001
  • In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using cylinder type reactor and packed-bed reactor. An experimental investigation has been conducted for NO concentration of 50[ppm], 100[ppm], 200[ppm] balanced with air, a gas flow rate of 5[1/min]. Ac voltage to discharge the gases was supplied. In the result, NOx removal rate in packed bed reactor is higher than that in cylinder type reactor. it is thought that plasma density in contact point of BaTiO$_3$ is significantly higher than that in cylinder reactor.

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Measurement and Analysis of Instantaneous Surface Temperature and Unsteady Heat Flux at Combustion Chamber of DOHC Gasoline Engine ; Cylinder Linder (DOHC 가솔린기관의 연소실 벽표면순간온도 및 비정상 열유속 측정 및 해석(제3보 : 실린더 라이너에 관한 연구))

  • 위신환;이종태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.3
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    • pp.1-11
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    • 2000
  • Instantaneous temperature probes were manufactured by pressing method. By using these probes, the instantaneous surface temperature and unsteady heat flux in the cylinder liner of DOHC engine were measured. The main results are as follows; ⅰ) the instantaneous surface temperature of cylinder liner are affected by the contact of piston ring as well as burning gas. ⅱ) the wall temperature of the siamese portion is much higher than other parts. ⅲ) it was shown that the rising trend of heat flux by burning gas are nearly limited to the 1/2-stroke distance from the top of cylinder liner.

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THREE DIMENSIONAL FINITE ELEMENT ANALYSIS ON THE MINIMUM CONTACT FRACTION OF BONE-IMPLANT INTERFACE (골조직과 임플랜트 계면의 최소접촉분율에 관한 삼차원 유한요소분석적 연구)

  • Jang, Kyoung-Soo;Kim, Yung-Soo;Kim, Chang-Whe
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.4
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    • pp.627-646
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    • 1997
  • In order to find the degree of osseointegration at bone-implant interface of clinically successful implants, models including the 3.75mm wide, 10mm long screw type $Br{\aa}nemark$ implant as a standard and cylinder, 15mm long, 5.0mm wide, two splinted implants, and implants installed in various cancellous bone density were designed. Also, the amount of load and material of prostheses were changed. The stress and minimum contact fraction were analyzed on each model using three-dimensional finite element method(I-DEAS and ABAQUS version 5.5). The results of this study were as follows. 1. 10mm long, 3.75mm diameter-screw type implant had $36.5{\sim}43.7%$ of minimum contact fraction. 2. Cylinder type implant showed inferior stress distribution and higher minimum contact fraction than screw type. 3. As implant length was increased, minimum contact fraction was increased a little, however, maximum principal stress was decreased. 4. Implants with a large diameter had lower stress value with slightly higher minimum contact fraction than standard screw type. 5. Two splinted implants showed no change of minimum contact fraction. 6. The higher bone density, the lower stress value. 7. The material of occlusal surface had no effect on the stress of the bone-implant interface.

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3D Dimensional Finite Element Analysis of Contact Stress of Gold Screws in Implant Partial Denture (임플란트 국소의치 금나사의 3차원 유한요소법 접촉응력 분석)

  • Lee, Myung-Kon
    • The Journal of Korean Academy of Dental Technology
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    • v.35 no.4
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    • pp.303-312
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    • 2013
  • Purpose: In this research, non-linear three dimensional finite element models with contact elements were constructed. For the investigations of the distributions of contact stresses, 3 units fixed partial dentures model were studied, especially on the interface of the gold screw and cylinder, abutment screw. Methods: 3 types of models were constructed ; the basic fixed partial denture in molar region with 3 units and 3 implants, the intermediate pontic fixed partial denture model with 3 units and 2 implants, and the extension pontic fixed partial denture model with 3 units and 2 implants. For all types, the external loading due to chewing was simulated by applying $45^{\circ}$ linguo-buccal loading of 300 N to the medial crown. For the simulation of the clamping force which clinically occurs due to the torque, thermal expansion was provided to the cylinder as a preload. Results: Under 300 N concentrated loading to the medial crown, the maximum contact stress between abutment screw and gold screw was 86.85~175.86MPa without preload, while the maximum contact stress on the same area was 25.59~57.84MPa with preload. Conclusion: The preloading affected the outcomes of the finite element stress analysis. Reflecting the clinical conditions, the preloading conditions should be considered for other practical study utilizing FEA. For the study of the contact stresses and related motions, various conditions, such as frictional coefficient changes, gap between contact surfaces, were also varied and analyzed.

The Development of Cylinder Shaped Air-breathing PEMFC (원통형 자연대류 방식 PEMFC 개발)

  • Lee, Kang-In;Lee, Se-Won;Park, Min-Soo;Chu, Chong-Nam
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.2
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    • pp.125-132
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    • 2009
  • Cylinder shaped air-breathing PEMFC has been developed to have small volume, low contact resistance and better air accessibility to the open cathode. This cylinder shaped design consists of an anode cylinder with helical flow channel and a cathode current collector with slits. The pressure distribution measurement according to the shapes was performed. The test result indicated that cylinder shaped fuel cell has better pressure distribution compared with the planar shaped fuel cell. The better pressure distribution was connected to the higher performance. The maximum power density of cylinder shaped fuel cell was about 20% higher than the planar shaped fuel cell. The maximum power density of the developed cylinder shaped air-breathing PEMFC with dry hydrogen was $220\;mW/cm^2$ and with humidified hydrogen was $293\;mW/cm^2$.

A study on the force control of MR cylinder with built-in valves (밸브 내장형 MR 실린더를 이용한 힘 제어에 관한 연구)

  • Song J.Y.;Ahn K.K.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1018-1023
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    • 2005
  • A new MR cylinder with built-in valves using MR fluid (MR valve) is suggested and fabricated for fluid control systems. The MR fluid is a newly developed functional fluid whose obvious viscosity is controlled by the applied magnetic field intensity. The MR cylinder is composed of cylinder with small clearance and piston with electromagnet. The differential pressure is controlled by the applied magnetic field intensity. It has the characteristics of simple, compact and reliable structure. The size of MR cylinder and piston has ${\varphi}30mm{\times}300mm\;and\;{\varphi}28.5mm{\times}120mm$ in face size, respectively and 0.8mm in gap length. Through experiments, it was found that the differential pressure is controlled by the applied magnetic field intensity under little influence of the flow rate, which corresponds to a pressure control valve. The differential pressure of 0.47MPa and contact force of 320N were obtained with the input current of 1.5A. The rising time of force was 1.1s in step response of a manipulator using the MR cylinder. The effectiveness of the MR cylinder was also demonstrated through the force control.

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on Contact Behaviour Characters of High pressure Wearing using Finite Element Analysis (고압용 웨어링의 접촉거동 특성에 대한 유한요소 해석)

  • 최동열;고영배;김청균
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.356-363
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    • 2001
  • Piston seal is a device designed to prevent leakage in split connecctions or between relatively moving part. Contact force, critical pressure at which extrusion occurs, leakage rate, fluid film thickness and friction force have been analyzed for some design parameter such as clearance between cylinder wall piston, depth of rectangular groove and pressure of sealed hydraulic fluid. In this paper, we analyze displacement and stress of Wearing by finite element analysis to understand Contact Behaviour Characters.

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Analysis of the thermoelastic begavior on the contact joint of compound cylinder (원통결합부의 열특성 해석 (제1보) -주축베어링 내륜계의 수치해석을 중심으로-)

  • 김선민;박기환;이선규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.629-634
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    • 1996
  • Heat generation in machine operating condition makes thermal deformation and thermalstress in the structure, which results in the change the contact characteristics of machine joint such s change of shrinkage fit, contact heat conductance and contact pressure. As the change of contact pressure is related to variation of static, dynamic and thermalcharacteristics, the prediction of transient contact perssure is strongly required. This paper presents some analytical results which will be effective to predict static and dynamic characteristics of the compound cylindrical structure.

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On the Contact Behavior Analysis and New Design of High Pressure Piston Seals

  • Kim, Chung-Kyun;Cho, Seung-Hyun;Kim, Sung-Won;Ko, Young-Jin;Kim, Jong-Soo
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.117-119
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    • 2002
  • In this paper, the geometry effectiveness and contact modes as functions of real contact length on a cap ring have been analyzed for high pressure sealing mechanism in reciprocating actuator. The reaction force and elastic strain energy density are very important parameters for analyzing the sealing performance of an ACGT ring seal. For the high pressure of 800bar and the maximum speed of 3m/s, the main piston is reciprocating along the linear line against the cylinder wall. The computed results indicate that the length ratio of a cap ring is more influential design parameter compared to that of the tribological contact mode. Thus, this paper recommends the discrete contact area rather than a conventional flat contact model. Especially, the sealing capacity is more improved when the length ratio of a cap ring is below 0.625.

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