• Title/Summary/Keyword: Diaphragm

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A Study on the Stress Evaluation for Steel Box Girder Support Diaphragm (강상형 합성교의 지점부 다이아프램 응력평가에 관한 연구)

  • Kim, Doo-Hwan;Park, Woo-Young
    • Journal of the Korean Society of Safety
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    • v.22 no.1 s.79
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    • pp.47-53
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    • 2007
  • A study is carried out to evaluate the stresses for steel box girder support diaphragm using finite elements method. This study includes the stress characteristic compared with experimental method for diaphragm design. The results from the finite elements method are compare with the results from experimental investigations and shown to give good agreement. The shear stresses were generally uniformed in the outer plane. increased rapidly above the bearing. The horizontal direct stresses were generally low except in the vicinity of the bearing and opening comer where a local increase in compressive stresses occured.

The Fabrication of Micro Actuator Used Micro Electro-Magnet and Magnetostrictive Thin Film (마이크로 전자석과 자기변형박막을 이용한 마이크로 엑추에이터의 제작)

  • Seo, Jee-Hoon;Yang, Sang-Sik;Jeong, Jong-Man;Lim, Sang-Ho
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.3328-3330
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    • 1999
  • In this paper, the fabrication of a micro actuator with a micro electromagnet and an actuator diaphragm is presented. The micro electromagnet consists of a magnetic core and a micro inductive planar coil. The actuator diaphragm is the p+ silicon diaphragm on both sides of which magnetostrictive materials are deposited by sputtering. The micro electromagnet is fabricated by sputtering, evaporating, etching and electroplating. The magnetic flux density of the micro electromagnet is measured by using the gauss meter. The deflection of the actuator diaphragm is measured by using the laser vibrometer and optic microscope.

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Calculation of rated output in diaphragm type miniature load cell (다이아프램 감지부 구조를 갖는 소형 로드셀의 정격출력 계산에 관한 연구)

  • Kwon, Young-Ha;Kang, Dae-Im;Joo, Jin-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.7 no.2
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    • pp.58-64
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    • 1990
  • As the miniature load cells have small inner space and sensing elements of which are thin and very sensitive to manufacturing conditions, it is very difficult to predict the rated outputs and control them by using the compensation resistor. The very useful equation has been derived for calculation of theoretical rated outputs for diaphragm type miniature load cells when commercial diaphragm strain gages are used. Four diaphragm type miniature load cells of which capacities are from 300 N to 1, 000 N and outer diameters are 20 mm and 26.5 mm are manufactured. The differences between calculating results and actural ones are less than 5%. According to numerical analysis the decrease of rated outputs caused to main error is examined in existence of loading button.

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A Complication of Diaphragm Repair Using a Gore-Tex (Expanded Polytetrafluorethylene) Membrane: A Case Report

  • Lee, Seungwook;Hong, Sung Yeon;Son, Jung A;Hyun, Seungji;Haam, Seokjin
    • Journal of Chest Surgery
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    • v.55 no.2
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    • pp.171-173
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    • 2022
  • A 65-year-old man underwent right trisectionectomy of the liver and reconstruction of the chest wall and diaphragm with a 2-mm Gore-Tex membrane due to recurrent hepatocellular carcinoma. After 3 years, the Gore-Tex membrane in the diaphragm migrated to the abdominal cavity and perforated the colon. We report a rare complication of a Gore-Tex membrane after diaphragm repair.

Use of real-time ultrasound imaging for biofeedback of diaphragm motion during normal breathing in healthy subjects

  • Cho, Ji-Eun;Hwang, Dal-Yeon;Hahn, Joohee;Lee, Wan-Hee
    • Physical Therapy Rehabilitation Science
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    • v.7 no.3
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    • pp.95-101
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    • 2018
  • Objective: To determine if the provision of visual biofeedback using real-time rehabilitative ultrasound imaging (RUSI) enhances the acquisition and retention of diaphragm muscle recruitment during exercise. Design: Two group pretest posttest design. Methods: Thirty healthy subjects were randomly assigned to the verbal feedback group (VG, n=15) or the visual and verbal feedback group (VVG, n=15). The VG performed breathing exercises 10 times with verbal feedback, and the VVG also performed breathing exercises 10 times with verbal feedback and visual feedback with the use of RUSI to measure changes in diaphragm thickness (DT). For DT, the mid-axillary lines between ribs 8 and 9 on both sides were measured in standing, and then the chest wall was perpendicularly illuminated using a linear transducer with the patients in supine to observe the region between rib 8 and 9 and to obtain 2-dimensional images. DT was measured as the distance between the two parallel lines that appeared bright in the middle of the pleura and the peritoneum. After one week, three repetitions (follow-up session) were performed to confirm retention effects. Intra- and between- group percent changes in diaphragm muscle thickness were assessed. Results: In the VVG, the intervention value had a medium effect size compared to the baseline value, but the follow-up value decreased to a small effect size. In the between-group comparisons, during the intervention session, the VVG showed no significant effect on percent change of DT but had a medium effect size compared to the VG (p=0.050, Cohen's d=0.764). During the follow-up session, retention effect did not persist (p=0.311, Cohen's d=0.381). Conclusions: RUSI can be used to provide visual biofeedback and improve performance and retention in the ability to activate the diaphragm muscle in healthy subjects. Future research needs to establish a protocol for respiratory intervention to maintain the effect of diaphragmatic breathing training using RUSI with visual feedback.

A Numerical Simulation on the Process of Diaphragm Opening in Shock Tube Flows (충격파관 유동의 파막과정에 관한 수치 시뮬레이션)

  • Shin, Choon-Sik;Jeong, June-Chang;Suryan, Abhilash;Kim, Heuy-Dong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.1
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    • pp.27-33
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    • 2009
  • Shock tube flow measurement has been often hampered a finite opening time of diaphragm, but there is no systematic work to investigate its effect on the shock tube flow. In the present study, both the experimental and computational works have been performed on the shock tube flows at low pressure ratios. The computational analysis has been performed using the two-dimensional, unsteady, compressible Navier-Stokes equations, based upon a TVD MUSCL finite difference scheme. It is known that the present computational results reproduce the experimental data with good accuracy and simulate successfully the process of diaphragm opening as a function of time. The concept of an imaginary center is introduced to quantify the non-centered expansion wave due to a finite opening time of diaphragm. The results obtained show that the diaphragm opening time is reduced as the initial pressure ratio of shock tube increases, leading to the effect of a finite opening time of diaphragm to be more remarkable at low pressure ratios.

Structural Behavior of Beam-to-Column Connections of Rectangular CFT Structures having Different Diaphragm Opening (콘크리트충전 각형강관구조의 다이아프램 개구부 형상에 따른 기둥-보 접합부 구조적 거동)

  • Kim, Ki Hoon;Lee, Myung Jae
    • Journal of Korean Society of Steel Construction
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    • v.27 no.3
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    • pp.289-298
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    • 2015
  • The steel tube of Concrete-Filled Tube(CFT) confines the concrete and the concrete restrains the buckling of the tube, The objective of this study is to investigate the influences of the opening shape of the through diaphragm in case of the rectangular CFT column-to-beam connection through the structural experiment. The experiment results are compared with analysis results obtained by using the FEM program. These results are shown that strength of the rectangular CFT column-to-beam connection have similar structural performance regardless of the opening shape if opening areas of the through diaphragm are same. Also in case the connection area/shape of the through diaphragm and the flange of H-beam are similar, it was ascertained that the bending stress occurred at the beam can be transferred to the column through the diaphragm.

Vibration Pattern Prediction through The Analysis on the Break-up Mode and the Heat Transfer Relationship of Slim Speaker Diaphragm (슬림 스피커 진동판의 분할진동 모드와 열전달 관계 분석을 통한 진동 패턴 예측)

  • Kim, Hyun-Kab;Kim, Hiesik
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.10
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    • pp.109-115
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    • 2016
  • In this paper, In this paper, we use two methods to compare the slim speakers. That way, the diaphragm scan using laser and diaphragm photographed using a thermal imaging camera. Slim speaker has the structure of a flat plate type. Break-up mode by this characteristic is displayed in a larger size. Further, since the installation space is narrow, it has limited moving coil cooling. As a result, the break-up mode slim speakers, a significant impact on quality. In this study, try to connect the break-up mode of the diaphragm, the heat transfer mode of the diaphragm. Experiment for comparison, a two-step. The first step is to measure the divided vibration through the vibration plate scan. The second step measures the diaphragm photographed using a thermal imaging camera. Then, compare the results of both of the same frequency. Thus, comparing the heat transfer pattern and the pattern of break-up mode. Tend to be analysis of break-up mode from the pattern comparison, and document for the optimum design.

Uplift Capacity of a Diaphragm Wall Installed in Ground with High Groundwater Table (높은 지하수위 지반 속에 설치된 지중연속벽의 인발저항력)

  • Hong, Won-Pyo;Chim, Neatha
    • Journal of the Korean Geotechnical Society
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    • v.30 no.9
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    • pp.5-17
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    • 2014
  • A series of model tests were conducted in order to observe the failure surface generated around a diaphragm wall embedded in ground with high groundwater table. Images of the soil deformation around the model wall were captured during the test. The configuration of the failure surface in soil around the model wall could be obtained from analyzing the image of the soil deformation. Based on the configuration of the failure surface observed in the model test, an analytical approach was proposed to predict the uplift capacity of a diaphragm wall installed in ground. The analytical approach considers not only the wall properties such as length, thickness and surface roughness of diaphragm walls but also the soil strength properties such as the internal friction angle and the cohesion of soil. The predicted uplift capacity of a diaphragm wall shows a good agreement with the experimental one measured in the model test.

Structural Characteristics of Welded Built-up Square CFT Column to Beam Connections with External Diaphragm (용접조립 각형 CFT 기둥-보 외다이아프램 접합부의 구조특성)

  • Lee, Seong Hui;Jung, Hun Mo;Kim, Dae Jung;Kim, Jin Ho;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.20 no.6
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    • pp.711-722
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    • 2008
  • Existing tube for concrete filled tubular structure is made through welding of four plates irrespective of tube thickness, so production performance is poor and special welding technique is needed to weld the internal diaphragm and through the diaphragm. Therefore, through manufacturing by cold forming development of beam to column connections that is no welding in position of stress concentration is needed. In this study the proposal of beam to column connections details and to making tube specimens by method of bending steel plates, we want to know the compositeeffect between internal anchor and concrete by processing on stress distribution and internal force evaluation of concrete filled tube beam to column connections with a variable of flange welding existence between column and beam, welding quantity between column and diaphragm, existence of concrete in tube, column with diaphragm and general column.