• Title/Summary/Keyword: Thermal Sleeve

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Thermal changes during implant site preparation with a digital surgical guide and slot design drill: an ex vivo study using a bovine rib model

  • Choi, Yoon-Sil;Oh, Jae-Woon;Lee, Young;Lee, Dong-Woon
    • Journal of Periodontal and Implant Science
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    • v.52 no.5
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    • pp.411-421
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    • 2022
  • Purpose: In this study, we aimed to evaluate the degree of heat generation when a novel drill design with an irrigation slot was used with metal sleeve-free (MF) and metal sleeve-incorporated (MI) surgical guides in an environment similar to that of the actual oral cavity. Methods: A typodont with a missing mandibular right first molar and 21 bovine rib blocks were used. Three-dimensional-printed MF and MI surgical guides, designed for the placement of internal tapered implant fixtures, were used with slot and non-slot drills. The following groups were compared: group 1, MI surgical guide with slot drill; group 2, MI surgical guide with a non-slot drill; and group 3, MF surgical guide with a slot drill. A constant-temperature water bath at 36℃ was used. The drilling was performed in 6 stages, and the initial, highest, and lowest temperatures of the cortical bone were measured at each stage using a non-contact infrared thermometer. Results: There were no temperature increases above the initial temperature in any drilling procedure. The only significant difference between the non-slot and slot groups was observed with the use of the first drill in the MI group, with a higher temperature in the non-slot group (P=0.012). When the heat generation during the first and the second drilling was compared in the non-slot group, the heat generation during the first drilling was significantly higher (P<0.001), and there was no significant difference in heat generation between the drills in the slot group. Conclusions: Within the limitations of this study, implant-site preparation with the surgical guide showed no critical increase in the temperature of the cortical bone, regardless of whether there was a slot in the drill. In particular, the slotted drill had a cooling effect during the initial drilling.

A Study on the behavior of contact stress at the lip seal of marine pump (박용 펌프 축용 립시일의 접촉응력 거동에 관한 연구)

  • Kim, Sung-Yun;Kim, Dae-Young;Ahn, Joong-Yeal
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.114-117
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    • 2004
  • The purpose of this study is to investigate geometric effect on the contact stress at a lip seal. The geometries of interest were angle, thickness of lip seal and width of contact surface. The contact stress was calculated by using a coupled thermo-mechanical analysis method. The friction thermal load between lip seal and sleeve was adopted to design load. Based on the FEA results, design variables for controlling the maximum contact stress at the lip seal were identified.

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A Study on the Insulation Design of Normal Joint in 345kV Oil-Filled Cable (345kV OF 케이블 보통접속재의 절연설계에 관한 연구)

  • Lee, Jung-Bum;Kang, Dong-Sik;Kang, Do-Hyun;Lee, Soo-Hyun
    • Proceedings of the KIEE Conference
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    • 1990.07a
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    • pp.308-311
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    • 1990
  • This paper presents the insulation design of 345kV OF cable normal joint which is essential to construction of underground transmission system. The insulation designs of stress relief cone, pencilling and sleeve were proposed in this paper, and the final insulation design was decided by the results of the electric field and thermal analysis using FEM. It is shown that the designed normal using proves the effect when the developing test is carried out to construct 345kV OF cable if the domestic underground transmission system.

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A Study on the subjective sensation of wearing knitwear made with silver yarn (은사 티셔츠의 주관적 착용감에 관한 연구)

  • Kwon, Do-Yeon;Kang, Mi-Jeong;Kwon, Young-Ah
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2008.10a
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    • pp.118-121
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    • 2008
  • The purpose of this study was to evaluate the wearing sensation of T-shirts made with silver combination yarns. The four different single jersey fabrics were knitted to make long sleeve T-shirts: cotton(C), cotton/silver(CS), polyester(P), and polyester/silver(PS). The four kinds of T-shirts were evaluated by six healthy male subjects in a climatic chamber($25^{\circ}C$, 65%RH, 0.5m/sec). The results were as follows. Thermal and fatigue sensation of wearing CS was best. It was found that overall subjective sensation was improved by using silver yarn with cotton for health knitwear.

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고온 열천이하중을 받는 액체금속로 Y-구조물에 대한 크립효과

  • Kim, Jong-Beom;Lee, Hyeong-Yeon;Yoo, Bong;Kwak, Dae-Young;Lim, Yong-Taek
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05b
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    • pp.659-665
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    • 1995
  • 액체금속로는 기존의 가압경수로와는 달리 55$0^{\circ}C$ 정도의 고온에서 운전이 되므로 고온 열응력이 중요한 문제로 대두되며 따라서 고은에서의 크립(Creep) 변형, 반복되는 기동과 정지 등으로 인한 되풀이 소성변형, 라체팅(Ratchetting), 크립과 소성의 상호작용 및 크립과 피로의 상호작용 등의 평가에 대한 기술 확립과 고온구조물에 대한 우리의 독자적인 설계방법을 개발하는 것이 필요하다 본 연구에서는 범용 유한요소해석코드인 ABAQUS의 축대칭 요소를 이용해서 액체 금속로 원자로용기와 이에 부착된 열소매(Thermal sleeve)를 Y-형태의 구조물로 모델링하여 반복되는 열천이하중에 대한 비탄성 구조해석을 수행하고 크립효과에 대한 영향을 분석하였다. 해석결과 액체금속로와 같은 고온구조물에 대하여 반복 열천이 하중과 고온 지속시간이 유발하는 크립효과가 크게 나타남을 알 수 있었다.

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The study Alarm & Auto Locking System of Electric Wire Compressor (경보음 발생 및 자동Locking 장치형 전선압축기에 대한 연구)

  • Choi Myeongho;Lee Sangho;Kim Dongmyung
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.800-802
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    • 2004
  • When an accident is happen due to using a bad Wire Compressor, some public resentments are caused and It cause lawsuit for we. In case, we will undergo a colossal financial loss. in addition to, Guide to improve quality of operation by using the number of times of pressing and pressing pressure with cooperative private enterprise. And because of needs for Thermal, Electrical and Chemical factor analysis of connection point of sleeve, expect to try improving problems of wire presser whole our company. We expect that reduce fault and save cost by this process. Consequently, we will prevent power losing and black out due to line faults by expulsion of inferiority equipment and prevent heating and line fault. This is possible using Alarming and Auto Locking Wire Compressor that is improve on this study.

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Development and Evaluation of Protective Clothing for Rose Farmers

  • Chae, Hyeseon;Kim, Sungchul;Oh, Youngsoon;Lee, Kyungsook;Kim, Hyocher;Park, Soonjee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.40 no.3
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    • pp.427-436
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    • 2016
  • Protective clothing developed for rose flower farmers has been evaluated to improve the working conditions. The requirements of rose farmers were first identified to design protective clothing for farmers working with thorny plants. A fit test was conducted to assess the thermal comfort and protective function against thorn pricking to compare and evaluate the usability of developed experimental clothing with existing working clothes. Based on the survey results of rose farmers' requirements, protective clothing was designed in the form of an apron (which was the most preferred after gloves) with a pattern designed for the production of experimental clothing. For the developed protective clothing, the strap and buckle closure method was selected to open the back of the body as much as possible; in addition, sleeves were made in the attachable form of a half-sleeve to protect the arms from the thorns. The fit test of the developed protective clothing and existing working clothes revealed the temperature and humidity inside the developed protective clothing to be significantly different in the back compared to existing work clothes. In addition to thermal sensations, the subjective humidity sensations were statistically significant different in the developed protective clothing compared to existing work clothes. The subjective protective function for thorn pricking was also found to be satisfactory.

A study on thermal and mechanical properties according to the structures of conductor sleeve and the method of connection for EHV Cables (전력 케이블용 접속 슬리브의 구조 및 접속 방법에 따른 특성 연구)

  • Kim, Young-Bum;Han, Bong-Soo;Ryu, Jeong-Hyun
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1493_1494
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    • 2009
  • 초고압 전력 케이블용 도체 접속을 위한 접속방법으로 압축형(compressing type), 용접형(welding type), 압축-용접형(CW type; compressing-welding type)의 슬리브는 물론 동과 알루미늄의 이종(nonidentical materials) 접속을 위한 슬리브를 개발 하였으며, 전기적, 기계적으로 검증된 제품 개발을 위하여, 슬리브의 구조 변경과 접속 방법의 차이뿐 아니라 접속 전후의 응력 평가를 위해 슬리브 시편의 인장시험(tensile strength) 결과에 따른 슬리브 제작 및 시험을 진행하였다. 신뢰성 있는 제품 개발과 데이터를 얻기 위하여 초고압용 지중 고압 케이블을 시험 시료로 적용하여 시험 선로(test loop)를 구성하였으며, 이를 통하여 구조와 재질에 따른 접속 방법, 이상 온도 상승 또는 국부적인 고온 부위 발생 여부 등의 전기 시험 및 열싸이클 전압 시험(heating cycle voltage test) 조건을 설정하여 시험 전후의 열신축 등 전기적, 기계적 특성을 평가하였다. 접속 슬리브의 구조 및 재질에 따른 위치별 발열 양상을 체크하였으며, X-ray 장비를 이용하여 슬리브 내부의 압축 및 충진 정도를 점검함으로써 기존 접속 슬리브 보완은 물론 개발된 접속 슬리브의 설계 기준 및 안전율을 설정 할 수 있었다.

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Wear Comfort of Double Jersey for Sports Wear (이중양면편 스포츠용 소재의 착용쾌적성 평가)

  • Jeong, Su-Kyung;Hong, Kyung-Hi
    • Korean Journal of Human Ecology
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    • v.12 no.2
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    • pp.253-263
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    • 2003
  • The purposes of this study were to find out an evaluation scale that could predict wear comfort and to investigate the effect of the skin-contacting fiber type on the subjective sensation and microclimate. Sensorial evaluation was basically followed by the Human Perception Analysis (HPA) interviewing 144 consumers. Sixteen female subjects were participated in the sleeve wear test with and without wearing vapor permeable water repellent outerwear. Experimental sleeves were constructed using the same double knit by turning inside out to control other material effects except the skin-contacting fiber type, hence each different side of double knit, cotton side and the cotton/polypropylene blend side, was next to skin in each trial of the experiment. As results, it was noted that the term representing a combined feeling of thermal and wetness sensation, and muggy appeared to be a powerful language to measure perceptual responses of human subject among five dimensions of evaluation. although the ordinary users did not use the term very often. As for the comfort properties of double knits, it seemed that subjects slightly more preferred polypropylene/cotton blend to cotton as the skin-contacting fiber type when they wore outerwear and their skin were covered with sweat, although the result was rot statistically significant and need to be confirmed under higher work load.

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Development of Large Propulsion Motor Bearings Considering Slope Conditions (경사조건을 고려한 대용량 추진 전동기용 베어링 개발에 대한 연구)

  • Oh, Seung Tae;Choi, Jin Woo;Kang, Byeng Hi;Kim, Jin;Choi, Seong Pil;Bin, Jae Goo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.2
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    • pp.241-248
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    • 2013
  • In this study, bearings were developed for a high-power propulsion motor operating in inclined operation conditions through a simulation and similitude-experimental methods using commercial rotating machinery dynamics analysis software. The developed journal bearing is electrically insulated and has low thermal conductivity because each part is connected with 2-4 -mm-thick epoxy plates. To realize an appropriate oil thickness, an oil lift system is adopted, and a half separated structure is applied to ensure the feasibility of maintaining very heavy components. This study discusses some of the key design aspects of sleeve bearing design for high-torque and low-speed propulsion motor applications. Furthermore, the conditions of variable slope tests are examined to prevent oil leakage from the bearing lip seal on the test rig.