• 제목/요약/키워드: restraint

검색결과 926건 처리시간 0.026초

A Study on Prevention of Weld Transverse Crack for Thick Plate(I) (후판 용접부의 횡균열 발생 방지에 관한 연구(I))

  • Jeong, Ho-Sin;Eom, Dong-Seok;Lee, Hae-U
    • Journal of Ocean Engineering and Technology
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    • 제13권3호통권33호
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    • pp.49-56
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    • 1999
  • Welding is a reliable process and is mainly adopted for fabricating heavy structures. Recently, transverse cracks in the weld metal is serious problem, and they affect cost, efficiency, safety and joint reliability for various welded structures. In this view of point, this study investigated the potential factors for weld metal transverse crack. The main results obtained are as follows; 1) The content of diffusible hydrogen in the commercial flux cored are welding wire was remarkable change by manufacturer. 2) The diffusible hydrogen content was thd main factor for weld metal transverse cracks. 3) Weld metal was immune to transverse cracking under the condition of low diffusible hydrogen content of high restraint condition. 4) The factors for weld metal transverse crack would be the content of diffusible hydrogen and restraint of weld joint.

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Differences of Eating Behavior between the obese and normal weight boys in High school (비만과 정상체중 남자고등학생들의 섭식행동 차이)

  • 신유선;조영숙
    • Korean Journal of Health Education and Promotion
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    • 제18권2호
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    • pp.83-95
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    • 2001
  • The purpose of this study is to describe Eating Behavior for High school boys who are obesity using three factors(dietary restraint, disinhibition, hunger). The subjects were 200 high school boys. The convenience sample is consist of 101 normal weight boys and 99 obeses weight boys. Data were collected between Mat 1 and June 20 in 2000 and analyzed using the SAS package. The results are as follows: 1. The first hypothesis was not supported that is, the normal weight boys much more doing dietary restraint than the obese boys. 2. The second hypothesis was supported that is, the obese boys more experience disinhibition than the normal weight boys. 3. The third hypothesis was supported that is, the obese boys more experience hunger than the normal weight boys. The eating behavior of obese boys is different that of normal weight boys, The obese boys more experience disinhibition and hunger than the normal weight boys, but dietary restraint was more done the normal weight boys than the obese boys.

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Risk Factors of Delirium Among the Patients at a Surgical Intensive Care Unit (일 종합병원 외과계 중환자실 환자의 섬망 발생 요인)

  • Chun, You Kyoung;Park, Jeong Yun
    • Journal of Korean Critical Care Nursing
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    • 제10권3호
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    • pp.31-40
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    • 2017
  • Purpose : This study examined the prevalence of delirium-related factors in a surgical intensive care unit (SICU). Methods : This retrospective study enrolled 73 patients who were admitted to an SICU from October 1, 2016 to March 20, 2017 and who had been hospitalized for more than 72 hours. Data was collected by reviewing electronic medical records. Results : Delirium occurred in 46 (63.0%) patients. Its related factors were age, education, mechanical ventilator, sleep, narcotics, physical restraint, and central line catheters. Conclusion : The results indicate that sleep and physical restraint are significant factors related to delirium occurrence. The results of this study can help in developing guidelines for the prevention of delirium.

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SIMPLE AND EFFECTIVE METHOD TO PREDICT THE OCCUPANT DYNAMIC RESPONSE UNDER SUDDEN IMPULSE LOADS

  • Elmarakbi, A.M.
    • International Journal of Automotive Technology
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    • 제7권7호
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    • pp.769-776
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    • 2006
  • A mathematical model is developed in this paper to define the interaction between the occupant and vehicle passenger compartment and to predict the occupant dynamic response during a sudden impulse load. Two different types of occupants are considered in this study, child and adult occupants. The occupants are considered as lumped masses connected to the child seat and vehicle's body masses by means of restraint systems. In addition, the occupant restraint characteristics of seat belt and airbag are represented by stiffness and damping elements. To obtain the dynamic response of the occupant, the equations of motion of the occupants during vehicle collisions are developed and analytically solved. The occupant's acceleration and relative displacement are used as injury criteria to interpret the results. It is demonstrated from the numerical simulations that the dynamic response and injury criteria are easily captured and analyzed. It is also shown that the mathematical models are flexible, useful in optimization studies and it can be used at initial design stage.

A Study on the Mechanical Properties and Residual Stress Distribution of Ti Welding Material (Ti 용접재의 기계적 특성 및 잔류응력의 분포에 관한 연구)

  • 최병기;장경천;국중민;정장만;구남열
    • Journal of the Korean Society of Safety
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    • 제18권1호
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    • pp.1-7
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    • 2003
  • The objective of this paper was to investigate the welding characteristics according to the restraint condition. the pass number, and the shield gas quantity with titanium commonly using in power stations, aircrafts, ships, and so forth. The residual stress distribution was measured under restraint and nonrestraint welding conditions. The tensile strength and elongation of the 4 pass welded specimen were shown higher about 10% and 30% than those of the 7 pass welded specimen at the same welding conditions respectably. Also, the more shield gas quantity and the shorter natural cooling time, the higher tensile strength and the lower elongation.

Evaluation of Models for Estimating Shrinkage Stress in Patch Repair System

  • Kristiawan, Stefanus A.
    • International Journal of Concrete Structures and Materials
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    • 제6권4호
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    • pp.221-230
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    • 2012
  • Cracking of repair material due to restraint of shrinkage could hinder the intended extension of serviceability of repaired concrete structure. The availability of model to predict shrinkage stress under restraint condition will be useful to assess whether repair material with particular deformation properties is resistance to cracking or not. The accuracy in the prediction will depend upon reliability of the model, input parameters, testing methods used to characterize the input parameters, etc. This paper reviews a variety of models to predict shrinkage stress in patch repair system. Effect of creep and composite action to release shrinkage stress in the patch repair system are quantified and discussed. Accuracy of the models is examined by comparing predicted and measured shrinkage stress. Simplified model to estimate shrinkage stress is proposed which requires only shrinkage property of repair material as an input parameter.

Effects of chemical restraint drugs on Doppler echocardiography in normal dogs (화학적 보정약이 정상견의 도플러 심초음파에 미치는 영향)

  • Yoon, Jung-hee
    • Korean Journal of Veterinary Research
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    • 제38권2호
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    • pp.413-418
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    • 1998
  • Intracardiac velocities were determined and the wave-forms described for 4 flow areas of the normal canine heart following administration of chemical restraint drugs including xylazine HCl, ketamine HCl, and thiopental sodium using pulsed wave Doppler echocardiography. The result was that xylazine HCl and thiopental sodium reduced intracardiac flow velocities through mitral, tricuspid, aortic and pulmonary valves. It is also thought that precautions are required before using these drugs. Patterns of wave-forms had no changes between control and treatment groups. Doppler echocardiography allows the clinician to determine flow velocities across the different valves and within the various chambers of the heart. It is shown that establishing normal values and those related to chemical restraint administrations and knowing what influences them should allow the clinician to non-invasively diagnose a variety of pathological cardiac conditions.

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Experimental Study on Tensile Creep of Coarse Recycled Aggregate Concrete

  • Seo, Tae-Seok;Lee, Moon-Sung
    • International Journal of Concrete Structures and Materials
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    • 제9권3호
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    • pp.337-343
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    • 2015
  • Previous studies have shown that the drying shrinkage of recycled aggregate concrete (RAC) is greater than that of natural aggregate concrete (NAC). Drying shrinkage is the fundamental reason for the cracking of concrete, and tensile creep caused by the restraint of drying shrinkage plays a significant role in the cracking because it can relieve the tensile stress and results in the delay of cracking occurrence. However, up till now, all research has been focusing on the compressive creep of RAC. Therefore, in this study, a uniaxial restrained shrinkage cracking test was executed to investigate the tensile creep properties caused by the restraint of drying shrinkage of RAC. The mechanical properties, such as compressive strength, tensile splitting strength, and Young's modulus of RAC were also investigated in this study. The results confirmed that the tensile creep of RAC caused by the restraint of shrinkage was about 20-30 % larger than that of NAC.

Effects of sheet and stamping process variables on side wall curl (딥 드로잉 벽면 만곡에 미치는 소재 및 가공조건의 영향)

  • 박기철;한수식;조태현;황상무
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 1998년도 춘계학술대회논문집
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    • pp.53-57
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    • 1998
  • In order to investigate the effects of the variables during the stamping process upon the side wall curl behavior, experiments and finite element analyses were done using a 90 degree draw-bending test. The variables considered were the die radius, the forming speed, the restraint force, the lubrication and the sheet grade. The experiments and simulation conditions were selected according to the design of experiment (DOE) approach. The effects of the restraint force, the lubrication and the forming speed were the same for both high strength and mild steels, but the effects of the die radius on the side wall curl were dependent on the magnitude of the die radius and the sheet grade. A straight side wall was observed for both high strength and mild steels when the die radius was about 2∼3 times of the sheet thickness. It was recommended that the restraint force, the forming speed and the friction be increased in order to reduce the side wall curl.

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Yielding behavior and yield strength of plate structure containing softened region (연화부를 포함한 판재의 항복거동과 항복강도)

  • 배강열;김희진;이태열;엄동석
    • Journal of Welding and Joining
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    • 제8권3호
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    • pp.79-88
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    • 1990
  • Welded joint often contains soft or softened regions such as the HAZ of TMCP steel welded with high heat input. In this study, the equivalent yield strength of plate structure containing softened region was predicted by FEM analysis, and its incremental behavior was explained with the results of the analysis. The calculated results of yield strength indicated the following for the plate structures. 1) As the softened region starts to yield, shear stress begins to build up along the boundary between base metal and softened region. This results in multi-axial stress condition which gives restraint on the softened region. 2) Restraint effect has a significant influence on the distribution of the shear stress, the nominal stress, and the strain. 3) The yielding behavior of softened region becomes the same as that of base metal when both ratios of length to width and thickness to width of softened region are larger than 30 and 13 respectively.

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