• Title/Summary/Keyword: Thread mechanism

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Analysis of the Mechanism of Thread-Embedding Acupuncture in Korean Medicine Beauty Treatment (한국의 한의 미용에서 매선요법 치료 기전에 대한 분석)

  • Eun-Young Park;Hyung-Sik Seo
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.36 no.4
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    • pp.113-121
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    • 2023
  • Objectives : The purpose of this study is to analyze the treatment mechanism of Thread-embedding acupuncture, which is used in Korean medicine beauty treatment. Methods : After searching papers published up to January 1, 2023 using the keyword "Thread-embedding" through the OASIS site, we selected beauty papers that mentioned the treatment mechanism of Thread-embedding acupuncture. Results : A total of 60 papers were retrieved: 19 papers on the topic of cosmetic diseases, 35 papers on the theme of other diseases, and 6 papers written unrelated to diseases. Among the 19 papers on the topic of cosmetic diseases, one unreadable paper was excluded. Among the 18 papers, we finally selected 6 papers that mentioned treatment mechanisms: 2 on facial wrinkles, 2 on obesity, 1 on breast enlargement, and 1 on transdermal hydration. The treatment mechanism of Thread-embedding acupuncture is that in the case of facial wrinkles, polydioxanone(PDO) is embedded to fill the volume, and as it decomposes, it causes a tissue reaction around the area. In obesity, it promotes fat decomposition by improving circulation, and promotes breast enlargement and elasticity through collagen formation. In transdermal hydration, it induces the production of surrounding fibers to increase skin elasticity and moisture. Conclusions : Thread-embedding acupuncture appears to have a cosmetic effect through a mechanism that promotes the production of collagen and elastic fibers in the subepidermal dermal layer and increases the activity of skin moisturizing factors during the absorption process after the PDO suture is embedded.

Experimental study on stripping mechanism of tension controlled bolts (TC볼트의 스트리핑 메카니즘에 대한 실험적 연구)

  • 신근하
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.1
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    • pp.111-118
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    • 2000
  • Over tightening experiments of the tension-controlled bolts are carried out and the stripping mechanism is reviewed base on the observed results. There are two modes of bolt failure due to the over tightening : one the fracture of the bolt the other the thread stripping Bifurcation between these two modes is rather delicate but it seems being related with the elastic flexibility of the bolt which depends upon the unused thread length. The fracture mode occurs in the bolts with good flexibility while the latter with bad one. According to the ISO Standard some meter coarse threads like M20 and M22 have the same pitch which causes bigger fastener to less resistance in shear and bending compared with the smaller one. however since UNC thread system adapts different pitch for different nominal diameter unified coarse threads show better stripping resistance than their corresponding meter threads.

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Finite Element Analysis of Manufacturing Process of a 12 Point Flange Head Bolt with Emphasis on Thread Rolling Process (나사전조공정을 중시한 12각플랜지볼트의 나사제조공정의 유한요소해석)

  • Jang, S.J.;Lee, M.C.;Shim, S.H.;Son, Y.H.;Yoon, D.J.;Joun, M.S.
    • Transactions of Materials Processing
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    • v.19 no.4
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    • pp.248-252
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    • 2010
  • In this paper, three-dimensional finite element analysis of thread rolling process of a 12 point flange head bolt is conducted using a rigid-plastic finite element method based metal forming simulator AFDEX 3D. A whole sequence of cold forming processes of a long shaft bolt composed of four forging stages and final thread rolling process is simulated to reveal the mechanism of thread formation. A mesh density control function is applied near the major plastic deformation region to achieve computational efficiency. It has been shown both numerically and experimentally that longitudinal lengthening or shortening is negligible in thread rolling.

Dynamics of lockstitch sewing process

  • Midha, Vinay Kumar;Mukhopadhyay, A.;Chattopadhyay, R.;Kothari, V.K.
    • The Research Journal of the Costume Culture
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    • v.21 no.6
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    • pp.967-973
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    • 2013
  • During high speed sewing, the needle thread is exposed to dynamic loading, short strike loading, inertia forces, friction, rubbing, force of check spring, bending, pressure, friction, impact, shock and thermal influence. The dynamic thread loading/tension alters throughout the stitch formation cycle and along its passage through the machine. The greatest tensile force occurs at the moment of stitch stretching, when the take up lever pulls for required thread length through the tension regulator. These stresses act on the thread repeatedly and the thread passes 50-80 times through the fabric, the needle eye and the bobbin case mechanism, before getting incorporated into the seam, which result in upto 40% loss in tensile strength of the sewing thread. This damage in the sewing thread adversely affects its processing and functional performance. In this paper, the contribution of dynamic loading, passage through needle and fabric, and bobbin thread interaction in the loss in tensile properties has been studied. It is observed that the loss in tensile properties occurs mainly due to the bobbin thread interaction. Dynamic loading due to the action of take up lever also causes substantial loss in tenacity and breaking elongation of cotton threads.

Implementation of Parallel Task Creation Mechanism in POSOX Thread (POSIX Thread를 이용한 병렬 태스크 생성 메커니즘의 구현)

  • 윤봉식;황선태
    • Proceedings of the Korean Information Science Society Conference
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    • 1999.10c
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    • pp.759-761
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    • 1999
  • 본 논문에서는 동적 병렬 태스크를 추출하는 메커니즘을 공유 메모리 구조상에서 구현하는데 있어서 최적화 기법에 대해서 소개한다. 최대의 호환성을 고려하여 POSIX thread와 C언어를 사용하였는데 이에 따른 오버헤드를 여러 가지 구현 기법을 사용하여 줄이고자 노력하였다. 그리고 병렬 처리시 대부분의 계산은 각 처리기에서 순차 계산에 의해 이루어지므로 이 순차 계산시에 발생하는 오버헤드를 줄이는 것을 최우선으로 하였다.

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Study of Cutting Characteristics in High Speed Synchronized Tapping (고속 동기 탭핑에서의 절삭 특성에 관한 연구)

  • 정용수;이돈진;김선호;안중환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.304-307
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    • 2002
  • High speed machining was accomplished. through the technological advances which covers the whole field of mechanical industry. But tapping have many troubles because of its complicate cutting mechanism, for example. tool damage, chip elimination and synchronization between spindle rotation and feed motion. But High speed tapping is so important that it marches in step with the flow of the times and make improvement in the productivity. In this paper we analyze mechanism of high speed synchronized tapping with the signal of tapping torque and spindle speed obtained through the newly developed high speed tapping machine(NTT-30B). We made an experiment with this machine on condition of various speed from 1000rpm to 10000rpm. As one complete thread is performed through the whole chamfer cutting, cutting torque increases highly in chamfer cutting, but smoothly in full thread cutting functioning of the threads guide. And the size of cutting torque according to spindle speed(rpm) was not enough of a difference to be conspicuous.

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Transition of Rivulet Flow from Linear to Droplet Stream

  • Kim, Ho-Young;Kim, Jin-Ho;Kang, Byung-Ha;Lee, Seung-Chul;Lee, Jae-Heon
    • International Journal of Air-Conditioning and Refrigeration
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    • v.10 no.3
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    • pp.147-152
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    • 2002
  • When a liquid is supplied through a nozzle onto a relatively non-wetting inclined solid surface, a narrow rivulet forms. There exist several regimes of rivulet flow depending on various flow conditions. In this paper, the fundamental mechanism behind the transition of a linear rivulet to a droplet flow is investigated. The experiments show that the droplet flow emerges due to the necking of a liquid thread near the nozzle. Based on the observation, it is argued that when the retraction velocity of a liquid thread exceeds its axial velocity, the bifurcation of the liquid thread occurs, and this argument is experimentally verified.

A Study of Rivulet Flow on Inclined Surface (경사면에서의 리뷸릿 유동에 관한 연구)

  • Kim, Jin-Ho;Kim, Ho-Young;Lee, Jae-Heon
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.576-581
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    • 2001
  • When a liquid is supplied through a nozzle onto a relatively nonwetting inclined solid surface, a narrow rivulet forms. This work provides novel physical insights into the following phenomena in the rivulet flow that have not been well understood to date. Firstly, the fundamental mechanism behind the transition of a linear rivulet to a droplet flow is investigated. The experiments show that the droplet flow emerges due to the necking of a liquid thread near the nozzle. Based on the observation, it is argued that when the retraction velocity of a liquid thread exceeds its axial velocity, the bifurcation of the liquid thread occurs, and this argument is experimentally verified. Secondly, a discussion on the curved motion of a meandering rivulet is given. This study proposes the contact angle hysteresis as a primary origin of the centripetal force that enables the rivulet's curved motion A simple scaling analysis based on this assumption predicts a radius of curvature which agrees with the experimental observation.

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A Study of Rivulet Flow on an Inclined Solid Surface (경사면에서의 리뷸릿 유동에 관한 연구)

  • 김진호;김호영;강병하;이재헌
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.10
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    • pp.1042-1048
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    • 2001
  • When a liquid is supplied through a nozzle onto a relatively non-wetting inclined solid surface, a narrow rivulet forms. This work provides novel physical insights into the following phenomena in the rivulet flow that have not been well understood to date. Firstly, the fundamental mechanism behind the transition of a linear rivulet to a droplet flow is investigated. The experiments show that the droplet flow emerges due to the necking of a liquid thread near the nozzle. Based on the observation, it is argued that when the axial velocity of a liquid is slower than the retraction velocity of its thread, the bifurcation of the liquid thread occurs, and this argument is experimentally verified. Secondly, a discussion on the curled motion of a meandering rivulet is given. This study proposes the contact angle hysteresis as a primary origin of the centripetal force that enables the rivulet\`s curved motion. A simple scaling analysis based on this assumption predicts a radius of curvature which agrees with the experimental observation.

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Strength of connection fixed by TOBs considering out-of-plane tube wall deformation-Part 1: Tests and numerical studies

  • Wulan, Tuoya;Wang, Peijun;Xia, Chengxin;Liu, Xinyu;Liu, Mei;Liu, Fangzhou;Zhao, Ou;Zhang, Lulu
    • Steel and Composite Structures
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    • v.42 no.1
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    • pp.49-57
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    • 2022
  • This paper presents a study on the behavior of a bolted T-stub to square tube connection using Thread-fixed One-side Bolts (TOBs) through tests and numerical simulations. It outlines a research work of four connections with focus on the failure modes and strengths of the connection under tensile load. It was observed that the thread anchor failure caused by shear failure of hole threads controlled the final failure of the connection in the tests. Meanwhile, the out-of-plane deformation of tube wall resulted in the contact separation between hole threads and bolt threads, which in turn reduced the shear strength of hole threads. Finite element models (FEMs) allowing for the configuration details of the TOBs fixed connection are then developed and compared with the test results. Subsequently, the failure mechanism of hole threads and stress distribution of each component are analyzed based on FEM results. It was concluded that the ultimate strength of connection was not only concerned with the shear strength of hole threads, but also was influenced by the plastic out-of-plane deformation of tube wall. These studies lay a foundation for the establishment of suitable design methods of this type of connection.