• Title/Summary/Keyword: tube-support

Search Result 285, Processing Time 0.028 seconds

Analysis of Two-Dimensional Fretting Wear Using Substructure Method (부분구조법을 이용한 2차원 프레팅 마모 해석)

  • Bae, Joon-Woo;Chai, Young-Suck;Lee, Choon-Yeol
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.31 no.7 s.262
    • /
    • pp.784-791
    • /
    • 2007
  • Fretting, which is a special type of wear, is defined as small amplitude tangential oscillation along the contacting interface between two materials. In nuclear power plants, fretting wear caused by flow induced vibration (FIV) can make a serious problem in a U-tube bundle in steam generator. In this study, substructure method is developed and is verified the feasibility for the finite element model of fretting wear problems. This method is applied to the two-dimensional finite element analyses, which simulate the contact behavior of actual tube to support. For these examples, computing time can be reduced up to 1/5 in comparisons with conventional finite element analyses.

자동차 파워스티어링용 유압호스의 맥동감쇠특성

  • 김도태;이종만;윤인균
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1997.04a
    • /
    • pp.196-202
    • /
    • 1997
  • A reinforced hydraulic hoses,caiied a resonator hoses,with fixible metal tube are commonly used in automotive power steering hydraulic systems to attenuate and eliminate the objectionable fluid borne noise(pressure ripple) or vibration produced by a pump or steering gear. To achieve better nose attenuation in automotile vehicles, the investigations on propagation and attenuation characteristics of fluid borne pressure ripple in power steering hydraulic ciruit are required. So, this paper descibes a mathematical model of hydraulic hoses to support design the power steering hydraulic circuit and analyze the attenuation characteristics of flow and pressure ripples. The model is based on the transfer matrix approach. The experimental results show that the pulsation attenuation characteristics of hydraulic house is remarkably affected by the flexible metal tube inserted coaxially inside a hydraulic hose with a finite length as well as viscoelastic properties of house wall. It is also shown that the predicted results bymodel proposed here agree well with the measured results over a wide frequency range. These results will assist in the modeling and design of hydraulic hoses, and hear, should provide a means for designing a quieter automotive power steering hydraulic systems.

On the congruence of some network and pom-pom models

  • Tanner, Roger I.
    • Korea-Australia Rheology Journal
    • /
    • v.18 no.1
    • /
    • pp.9-14
    • /
    • 2006
  • We show that some network and pom-pom constitutive models are essentially the same. Instead of the usual confrontation, we suggest that the two approaches can offer useful mutual support: vital information about network destruction rates found from detailed pom-pom calculations can be used to improve the network models, while deductions about network creation rates can pinpoint areas needing further attention in the tube modelling area. A new form of the PTT model, the PTT-X model, results in improved shear and elongational flow descriptions, plus an improved recoil behaviour. The remaining problems of strain-time separation, second normal stress difference description, and reduction of parameters are also discussed and some suggestions for progress are offered.

Characteristic Analysis of Electromagnetic-ultrasonic Guided Waves for Defect Signals in Condenser Tubes (전자기유도초음파를 이용한 복수기 전열관 결함신호 특성분석)

  • Choi, Sang-Hoon;Wang, Gi-Nam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.27 no.3
    • /
    • pp.174-178
    • /
    • 2015
  • This paper describes a signal processing technique for identifying signals from defects by using an electromagnetic-ultrasonic guided waves method based on a magnetostrictive sensor that generates a torsional mode (T(0, 1)). Because this technique is based on the digital filtering, the filtered signals provide information on the relationship between the cutoff frequency of band-pass filter and the characteristic of defect signals in heat exchange tubes. To verify the performance of the technique, artificial defects with various thickness reduction ration and shape were machined in titanium tubes, and digital filtering results are reported. The results show that digital filtering provides information to the identify shape of defects and the contact condition between the tube and support ring. Therefore, the proposed technique has good potential as a tool for evaluating the integrity of heat exchange tubes.

A Study on the Stiffness Characteristic of Repeated Unit Cell Structure (반복되는 구조물의 강성특성 연구)

  • Park, Soo;Seon, Kwang-Sang;Koo, Jae-Mean;Seok, Chang-Sung;Park, Tae-Jung
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.27 no.3
    • /
    • pp.111-117
    • /
    • 2010
  • The repeated unit cell structure is applied to the composite, the carbon nano tube and sandwich panel. In this paper, a study on the stiffness of unit cell structure has been performed with the tube support plate of the steam generator. For this, repeated unit cell structure's equivalent elastic constant and poisson's ratio was evaluated through FEA and tests under the elastic range load. Also we evaluated the effect on the specimen size from results.

Congenital Chylothorax Treated by Ligation of the Thoracic Duct [Report of A Case] (흉관결찰로 치유한 선천성 유미흉치험 1례 보고)

  • Bang, Jong-Gyeong;Han, Seung-Se;Kim, Gyu-Tae
    • Journal of Chest Surgery
    • /
    • v.21 no.1
    • /
    • pp.191-195
    • /
    • 1988
  • Chylothorax in the neonatal period is a rare cause of respiratory distress. Surgical ligation of the thoracic duct is rarely necessary in congenital chylothorax. A 3 day-old newborn delivered by the cesarean section showed signs of respiratory distress suddenly and diagnosed as chylothorax on the right hemithorax. Conservative management such as multiple thoracenteses and tube thoracostomy drainage with nutritional support failed to close the leakage. At age of 60 days, we performed a supradiaphragmatic mass ligature of the thoracic duct visualized after injection of methylene blue into the thigh subcutaneously. Postoperatively, chylous effusion occurred in the left hemithorax and successfully treated with chest tube drainage for several days.

  • PDF

A Case of Hypopharyngeal Perforation in a Trauma Patient on Ventilatory Support (호흡기 보조를 받는 환자에서 발생한 하인두 천공)

  • Park, Kwon Jae;Park, Chang Min;Jung, Sang Seok;Bang, Jung Hee
    • Journal of Trauma and Injury
    • /
    • v.27 no.3
    • /
    • pp.75-78
    • /
    • 2014
  • Hypopharyngeal perforation is a rare, but fatal, complication. Clinical signs and symptoms of this condition are neck pain, odynophagia, dysphagia, fever, vomiting, cervical swelling and subcutaneous emphysema. However, these signs are obscured in patient suffering from severe trauma who has had an endotracheal tube inserted, which delay proper evaluation and treatment. Here, we report a case of hypopharyngeal perforation in a trauma patient who had an endotracheal tube inserted for mechanical ventilation.

Promotion of mental health through emotional sharing: K-culture, Yangbanchum dance performance on YouTube (https://youtu.be/KM-pIjQOwAE)

  • Ko, Kyung Ja;Cho, Hyun-Yong
    • CELLMED
    • /
    • v.12 no.2
    • /
    • pp.8.1-8.2
    • /
    • 2022
  • The Yangbanchum was reconstructed based on mask play that had been handed down in Goseong, Gyeongsangnam-do, Korea. Talnori, called Goseong Ogwangdae, is a Korean folk cultural heritage designated as National Important Intangible Cultural Property No. 57. This mask play provides catharsis to the audience by unraveling the hypocrisy and lies of the aristocrats through satire and humor. Our performance team, the ensemble Better Than Medicine (eBTM) used a large fan (Boochae)to create a performance that blew away anxiety and pain. Watching this performance, the performer and the audience feel the consensus of sharing emotions and send strong bonds and support to each other. This study provides that Yangbanchum dance promotes the mental health by feeling emotional sharing through vicarious satisfaction and mirror effect.

Verification of Effective Support Points of Stern Tube Bearing Using Nonlinear Elastic Multi-Support Bearing Elements (비선형 탄성 다점지지 베어링 요소를 이용한 선미관 베어링의 유효지지점 검증)

  • Choung, Joon-Mo;Choe, Ick-Heung;Kim, Kyu-Chang
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.42 no.5 s.143
    • /
    • pp.479-486
    • /
    • 2005
  • The final goal of shift alignment design is that the bearing reaction forces or mean pressures are within design boundaries for various service conditions of a ship. However, it is found that calculated bearing load can be substantially variable according to the locations of the effective support points of after sterntube bearing which are determined by simple calculation or assumption suggested by classification societies. A new analysis method for shaft alignment calculation is introduced in order to resolve these problems. Key concept of the new method is featured by adopting both nonlinear elastic and multi-support elements to simulate a bearing support Hertz contact theory is basically applied for nonlinear elastic stiffness calculation instead of the projected area method suggested by most of classification societies. Three loading conditions according to the bearing offset and the hydrodynamic moment and twelve models according to the locations of the effective support points of sterntube bearings are prepared to carry out quantitative verifications for an actual shafting system of 8000 TEU class container vessel. It is found that there is relatively large difference between assumed and calculated effective support points.

A Study on the Nutritional Assessment and the Effects of Enteral Nutritional Supports of Tube Feeding In-patients (경관급식 중인 입원환자의 영양상태 평가와 영양 보충제 투여의 영향에 관한 연구)

  • 윤숙영;김성미
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.25 no.5
    • /
    • pp.855-864
    • /
    • 1996
  • The purpose of this study is to evaluate nutritional status of tube feeding patients, and to investigate the effects of giving enteral nutritional support to them. 83 in-patients have been examined for their nutritional status. The mean caloric density was 0.77kca1/m1. 36.1% to 75.9% of them were malnourished in terms of biochemical assessment. The energy intake showed the significant and positive correlation in all biochemical parameters. And the protein intake showed the significant and positive correlation in total protein, serum albumin, serum iron, hemoglobin, hematocrit and TLC. But age was correlated negatively to serum albumin and transferrin. The amount of energy and protein intake has been significantly increased as the tube feeding duration became longer. Also the effect of enteral nutritional support for 6 weeks has been investigated. Case group(n=8) was administered 250kca1 of polymeric formula in addition to their usual diet, while control group(n=8) kept the amount of their original intake. When comparing the biochemical changes of the case group and those of control group at week 0 and week 6 respectively, it showed significant differences in total protein, serum transferrin and TLC. This study suggests that the malnourished status of tube feeding patients can be improved and even prevented if nutritional support is properly administered.

  • PDF