• Title/Summary/Keyword: 1st twisting

Search Result 13, Processing Time 0.012 seconds

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

  • 이민수;김승진;박경순
    • Textile Coloration and Finishing
    • /
    • v.16 no.1
    • /
    • 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.

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

  • Jeong Jong-Cheol;Cho Sea-Hyun;Seo Seong-Il;Kim Jung-Seok
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.30 no.4 s.247
    • /
    • 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.

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

  • 서영태
    • Journal of Ocean Engineering and Technology
    • /
    • v.8 no.2
    • /
    • 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
    • /
    • v.9 no.2
    • /
    • 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.

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

  • 김승진;안병훈;이민수
    • Textile Coloration and Finishing
    • /
    • v.11 no.6
    • /
    • 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
    • /
    • v.62 no.1
    • /
    • 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.

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

  • Chung, Hyung-Jin;Park, Jae-Gu;Kam, Min-Cheol
    • Journal of Korean Foot and Ankle Society
    • /
    • v.17 no.1
    • /
    • 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.

Clinical Observation of Bell's Palsy (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))

  • Kang, Sung-Keel;Kim, Yong-Suk
    • The Journal of Korean Medicine
    • /
    • v.16 no.2 s.30
    • /
    • pp.9-16
    • /
    • 1995
  • Forty four patients with Bell's palsy were treated with acupuncture from onset and clinical observation was carried on from March 1994 through Feburary 1995. Acupuncture treatment was done 3 times per week and the acupuncture points were LI4 Hapkok, ST36 Choksamni, LI20 Yonghyang, BL2 Ch'anjuk, TE17 Yep'ung, ST4 Chich'ang, ST6 Hyopko, GV26 Sugu, CV24 Sungjang, GB14 Yangbaek and Ex-HN4 Oyo. They were inserted to a depth of 0.5 to 1.0 cm. After insertion, manipulation was carried on until the patients felt strong numbness or De Qi sensation induced by rotating or twisting needles. Through-needling in lengths varying from 2.0 to 3.5 cm was also applied from ST4 Chich'ang to ST6 Hyopko, from GV26 Sugu or CV24 Sungjang to ST4 Chich'ang and from GB14 Yangbaek to Ex-HN4 Oyo. The mean age was 39.3 and 63.6% of the patients were women, including one pregnant woman. There was no recurrent palsy in this study. By applying the House-Brackmann facial nerve grading scales, patients were evaluated weekly from the first treatment to judged recovery or the 7th week of the treatment. 86.4% of the patients were recovered completely within 7 weeks and the average healing period was 3.7 weeks.

  • PDF

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

  • Yu, Sun-O;Park, Yong-Wook;Kim, Joo-Sung;Lee, Gi-Jun
    • Journal of Korean Foot and Ankle Society
    • /
    • v.8 no.1
    • /
    • 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

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

  • Kim, Hyo Seon
    • Korean Journal of Occupational Health Nursing
    • /
    • v.3
    • /
    • 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