• 제목/요약/키워드: 1st twisting

검색결과 13건 처리시간 0.023초

벨트 가연기의 공정조건에 따른 장력변화 (Effect of the Processing Condition to the Yarn Tension on the Belt-type Texturing m/c)

  • 이민수;김승진;박경순
    • 한국염색가공학회지
    • /
    • 제16권1호
    • /
    • pp.1-4
    • /
    • 2004
  • This research surveys the twisting and untwisting tensions according to the various processing conditions of belt type texturing such as draw ratio, 1st heater temperature and velocity ratio. The 1st heater temperature was changed from 1606{\circ}C\; to\; 220^{\circ}C$, draw ratio was changed from 1.6 to 1.9 and velocity ratio was changed from 1.4 to 1.8. The twisting and untwisting tensions are measured with the variation of these processing conditions, in addition, the untwisting tension(T2) and tension ratio(T2/Tl) according to the various processing conditions are analysed with the false twist mechanism which is affected to the physical properties of draw textured yams.

복합재 철도차량 차체 고유진동수에 대한 해석 및 시험적 연구 (Analytical and Experimental Studies on the Natural Frequency of a Composite Train Carbody)

  • 정종철;조세현;서승일;김정석
    • 대한기계학회논문집A
    • /
    • 제30권4호
    • /
    • pp.473-480
    • /
    • 2006
  • This paper explains analytical and experimental studies to evaluate the natural frequency of a composite carbody of Korean tilting train. The composite carbody with length of 23m was manufactured as a sandwich structure composed of 40mm-thick aluminium honeycomb core and 5mm-thick woven fabric carbon/epoxy face. From the finite element analysis, the 1st bending and 1st twisting natural frequency of the composite carbody were 11.67Hz and 14.4Hz, respectively. In order to verify the analytical results, the natural frequency measuring tests were performed. The measured 1st bending and twisting natural frequencies of the composite carbody were 10.25Hz and 11.0Hz, respectively. Both of these results satisfied the design requirement.

내부 유체 유동을 포함한 해저 파이프 라인의 인장 굽힘 비틀림 운동 방정식 (The Equations of Motion for the Stretcthing, Bending and Twisting of a Marine Pipeline Containing Flowing Fluids)

  • 서영태
    • 한국해양공학회지
    • /
    • 제8권2호
    • /
    • pp.151-156
    • /
    • 1994
  • The equations of motion of a submarine pipeline with the internal flowing fluid and subject to hydrodynamic loadings are derived by using Hamilton's principle. Coupling between the bending and the longitudinal extension due to axial load and thermal expansion are considered. Coupling between the twisting and extension are not considered. The equations of motion are well agreed with the results which are derived by the vector method.

  • PDF

Image Noise Reduction Using Structural Mode Shaping for Scanning Electron Microscopy

  • Hamochi, Mitsuru;Wakui, Shinji
    • International Journal of Precision Engineering and Manufacturing
    • /
    • 제9권2호
    • /
    • pp.28-33
    • /
    • 2008
  • In a scanning electron microscope (SEM), outside acoustic noise causes image noise that distorts observations of the specimen being examined. A SEM that is less sensitive to acoustic noise is highly desirable. This paper investigates the image noise problem by addressing the mode shapes of the base plate and the transmission path of the acoustic noise and vibration. By arranging the position of the rib, a new SEM base plate was developed that had twisting as the 1st and 2nd modes. In those two twisting modes, vibration nodes existed near the center of the base plate where the specimen chamber is placed. Less vibration was transmitted to the chamber and to the specimen by the twisting modes compared to bending ones, which are the 2nd and 3rd modes for a rectangular plain base plate. An SEM with the developed base plate installed exhibited a significant reduction of image noise when exposed to acoustic noises below 250 Hz.

폴리에스테르 필라멘트의 텍스쳐링 공정조건이 사물성에 미치는 영향 (Effect of Processing Condition of Texturing M/C on the Physical Properties of Textured Polyester Filament)

  • 김승진;안병훈;이민수
    • 한국염색가공학회지
    • /
    • 제11권6호
    • /
    • pp.18-23
    • /
    • 1999
  • PET POY(pre-oriented-yam) were treated by false twister to high bulky. False twister have many processing parameters velocity ratio(VR), belt cross angle$(\theta)$, 1st heater temp. and K(twisting tension/untwisting tension). we analyzed the effect of properties of textured polyester yam on processing condition. Initial modulus, thermal stress, No. of snarl is decreased by 1st heater. In VR=1.97, Dry and wet shrinkage is increased but is decreased by 1st heater in VR=1.564. K/S and cristallinity tend to increase by decreasing VR.

  • PDF

Nonlinear torsional analysis of 3D composite beams using the extended St. Venant solution

  • Yoon, Kyungho;Kim, Do-Nyun;Lee, Phill-Seung
    • Structural Engineering and Mechanics
    • /
    • 제62권1호
    • /
    • pp.33-42
    • /
    • 2017
  • We present in this paper a finite element formulation for nonlinear torsional analysis of 3D beams with arbitrary composite cross-sections. Since the proposed formulation employs a continuum mechanics based beam element with kinematics enriched by the extended St. Venant solutions, it can precisely account higher order warping effect and its 3D couplings. We propose a numerical procedure to calculate the extended St. Venant equation and the twisting center of an arbitrary composite cross-section simultaneously. The accuracy and efficiency of the proposed formulation are thoroughly investigated through representative numerical examples.

족근 중족 관절 잠재의 손상에 대한 진단 및 치료 (Diagnosis and Treatment of Occult Lisfranc Injury)

  • 정형진;박재구;감민철
    • 대한족부족관절학회지
    • /
    • 제17권1호
    • /
    • pp.34-39
    • /
    • 2013
  • Purpose: To evaluate the effectiveness of intraoperative stress test for diagnosis of occult Lisfranc injury. Materials and Methods: Between April 2009 and October 2012, 21 patients with occult Lisfranc injuries underwent intraoperative stress test and internal fixation. There were 11 males and 10 females with an average age of 45.3 years (range, 23~79 years). Injuries were caused by traffic accident in 10 cases, indirect force (twisting injury) in 8 cases, and crush in 2 cases, falling from a height in 1 case. Unstable injuries on stress radiograph in occult injury of Lisfranc joint were treated by open reduction or closed reduction and fixation with cannulated screw or K-wire. Radiological evaluation was assessed according to preoperative and postoperative diastasis between $1^{st}$ and $2^{nd}$ metatarsal base. Results: Assoicated injuries were 9 cases of metatarsal fractures, 6 cases of cuneiform fractures and 6 cases of both metatarsal and cuneiform fractures. Medial and middle column fixation was in 13 cases, and three columns fixation was in 8 cases. Initial diastasis between $1^{st}$ and $2^{nd}$ metatarsal base was 2.8 mm (1.3~4.7 mm) on AP radiograph and postoperative diastasis between $1^{st}$ and $2^{nd}$ metatarsal base was 1.2 mm (0.5~2.4 mm) on AP radiograph. Conclusion: Even there is no sign of clear Lisfranc injury, it is necessary to pay attention and give evaluation on circumstances of occult Lisfranc injuries with metatarsal or cuneiform fractures. Intraoperative stress test is helpful to diagnose an occult Lisfranc injury. For unstable injuries on stress radiographs of occult Lisfranc joint injury, operative treatment with open or closed reduction and internal fixation is useful method.

침치료(鍼治療)에 의한 말초성(末梢性) 안면신경마비(顔面神經麻痺)의 임상적(臨床的) 관찰(觀察) (Clinical Observation of Bell's Palsy)

  • 강성길;김용석
    • 대한한의학회지
    • /
    • 제16권2호
    • /
    • pp.9-16
    • /
    • 1995
  • 1994년 3월부터 1995년 2월까지 1년동안 말초성 안면신경마비로 경희의료원 한방병원 침구1과에 침치료를 받기 위하여 내원한 환자중 발병한지 1주일 이내로 이부(耳部) 대장포진(帶狀疱疹)이나 종양 또는 외상을 당하지 않은 초발환자 44명을 대상으로 일주일에 3회씩 합곡(合谷)(L14), 족삼리(足三里)(ST36), 영향(迎香)(LI20), 찬죽(BL2), 예풍(TE17), 지창(地倉)(ST4), 협차(頰車)(ST6), 수구(水溝)(GV26), 승장(承漿)(CV24), 양백(陽白)(GB14)과 어요(魚腰)(Ex-HN4)를 선혈(選穴)하여 자침하고 치료경과를 관찰하였다. 지창(地倉)에서 협차(頰車), 수구(水溝)와 승장(承漿)에서 지창(地倉), 양백(陽白)에서 어요(魚腰)로는 투자법을 실시하였다. 환자의 평균연령은 39.3세이었고, 여성이 63.6%를 차지하였고 그중 한 명은 임신중이었다. 안면신경마비의 회복판정 척도는 House-Brackmann facial nerve grading scales를 사용하여 초진부터 초진후 7주까지 또는 7주이내 완전히 회복될 때까지 매주 평가하였다. 86.4%의 환자가 초진후 7주이내에 완전히 회복 되었으며, 회복되는데 걸리는 기간은 평균 3.7주로 관찰되었다.

  • PDF

초기 진단에 어려움이 있는 불안정성 족근 중족 관절 미세 손상에 대한 도수 정복 및 내고정술 후 임상적 결과 (Clinical Results after Closed Reduction and Internal Fixation for Unstable Subtle Injuries of Lisfranc Joint)

  • 유선오;박용욱;김주성;이기준
    • 대한족부족관절학회지
    • /
    • 제8권1호
    • /
    • pp.71-75
    • /
    • 2004
  • Purpose: The purpose of this study was to evaluate retrospectively the clinical results of closed reduction and percutaneous screw fixation for unstable injuries on stress radiographs in subtle injuries of Lisfranc joint. Materials and Methods: From June 1997 to March 2003, 6 cases of unstable injuries on stress radiograph in subtle injuries of Lisfranc joint were treated by percutaneous cannulated screw fixation after closed reduction. All cases were injuried by indirect force (twisting injury). The average diastasis between the 1st and 2nd metatarsal base was 3 mm (2-4 mm) on initial nonweight bearing AP radiograph. The average follow-up period was 20 months. Clinical evaluation was assessed according to the American Orthopedic Foot and Ankle Society (AOFAS) midfoot score. Results: The AOFAS midfoot score was average 86 (80-90) points. The average diastasis between 1st and 2nd metatarsal base was 2 mm (1-3 mm) on weight bearing AP radiograph in final follow up. The final diastasis was increased slightly than diastasis in initial postoperative radiographs. But the clinical results were good. There was no correlation between the degree of diastasis and the clinical results. On weight bearing lateral radiograph, the average difference with normal foot in the distance between plantar aspect of 5th metatarsus and medial cuneiform was 2 mm (0-3 mm). One case had mild arthritic change on the radiographs. Conclusion: When the Lisfranc injuries, especially in the subtle injuries were suspicious, the stress views are helpful to assess stability of the Lisfranc injuries and planning of treatment. For unstable injuries on stress radiographs in subtle injuries of Lisfranc joint, closed reduction and percutaneous screw fixation is useful method to expect good clinical results.

  • PDF

병원 간호인력의 요통발생실태와 관련요인 (Low Back Pain of Hospital Nursing Personnel)

  • 김효선
    • 한국직업건강간호학회지
    • /
    • 제3권호
    • /
    • pp.21-30
    • /
    • 1993
  • For the purpose of disclosing the magnitude of low back pain problems of hospital nursing personnel and its possible causes, a questionaire survey was carried out on 418 nurses and nurse aides if a university hospital in Seoul. The results were as follows : 1. Of 418 nurse and nurse aides, 268 persons(64.1%) have experienced 1,145 spells of low back pain during 6-month period. 2. The pain and/or discomfort was mostly limited to the back, although 19% of the episodes accompanied radiating pain to the low extremities. 3. Of those with low back pain, 23 persons(8.6%) were medically diagnosed and 17 persons(6.3%)-underwent medical treatment. Those who sick leave amounted to 8 persons(3.0%). 4. The occurrence of low back pain showed significant association with assignment of duties(wards) and work shifts, while the association was not significant in terms of ranks, careers and overtimes. 5. The occurrence of low back pain was closely associated with lifting and carrying of loads, standing and twisting postures as well as the amount of work. 6. Among the nonoccupational factors, drinking showed statistically significant association with the occurrence of low back pain.

  • PDF