• 제목/요약/키워드: Fracture & dislocation

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노인요양시설에서 노인수발 담당자의 응급처치에 대한 교육수요도 조사 - 일개 도시를 중심으로 - (A Study on the Need for Emergency Care Education in Nursing Homes)

  • 엄동춘;성시경
    • 한국간호교육학회지
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    • 제15권1호
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    • pp.53-61
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    • 2009
  • Purpose: This study was conducted to evaluate the need for education for emergency care in nursing homes. Method: 312 people who were engaged in caring for the elderly at nursing homes in D-metropolitan c! ity answered the questionnaires about the experiences, the need, and the ideal methods of education for basic emergency care, from Jul. 1. 2007 to Jul. 30. 2007. Result: 69.9% were female. Only 7.1% were nurses and the rest did not have majors in the medical field. 83.0% had experienced education for emergency care, and 89.2%, 78.4% and 44.8% of them had been educated about cardiopulmonary resuscitation, airway obstruction care, and fracture/sprain/dislocation care respectively. Fifty-three who had not experienced education answered 'no opportunity' as a cause of non-education. The need for emergency care education was 4.53/5.00, and the desire to receive education was 2.81/3.00. Mainly workers wanted to be educated abo! ut airway obstruction (88.1%), and breathing assistance & cardiac massage (72.4%). Workers preferred to be educated 1-2 times per year for 2-3 subjects, through programs including both lecture and practice. Conclusion: It is essential to create an adequate program and apply it to the people engaged in caring for the elderly.

Nicoseal(Fe-29Ni-17Co) 합금의 Cyclic 크리프 특성 (Cyclic Creep Properties of Nicoseal(Fe-29Ni-17Co) Alloy)

  • 박용권;최재하
    • 열처리공학회지
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    • 제18권3호
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    • pp.177-182
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    • 2005
  • The steady state cyclic mechanism, and the behaviour of Nicoseal(Fe-29Ni-17Co) have been examined under the condition of square wave stress cyclic tension creep test at the temperature, stress and frequency range of $430{\sim}470^{\circ}C$($0.41{\sim}0.43T_m$), 353~383 MPa, and 3 cpm, respectively. Also, the relationship between cyclic creep and static creep have been examined. The stress exponents(n) for the static creep deformation of this alloy were 11.6, 10.0, 8.4 and 7.9 at the temperature of 430, 445, 460 and $470^{\circ}C$, respectively. The apparent activation energies (Q) for the static creep deformation were 54.2, 51.8, 49.7 and 46.8 kcal/mole for the stress of 353, 363, 373 and 383 MPa, From the above results, it could be considered that the cyclic creep accelaration phenomena was obtained and that the cyclic deformation for Nicoseal seemed to be controlled by dislocation climb over the range of experimental conditions. Nicoseal alloy under the cyclic creep conditions was obtained as P=(T+460)(logt+17). The failure plane observed by SEM showed up transgranular fracture at all range.

$SiC_P$/A1-Si 복합재료의 정적연화가 열간가공성에 미치는 영향 (Effects of Static Softening on Hot Workability of $SiC_P$/A1-Si COmposites)

  • 고병철;전정식;유연철
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1995년도 추계학술대회논문집
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    • pp.172-180
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    • 1995
  • Isothermal interrupted deformation behavior of 10vol.%SICp/AI-Si composites was investigated by hot torsion test at the temperature ranges from 27$0^{\circ}C$ to 43$0^{\circ}C$ and at strain rate range of 1.26X10-2~2.16X10-1/sec. With increasing pass strain, flow stresses were high compared to continuous deformation condition. Fractional softening was increased with temperature imterruption time and pass strain. Fractional softening of 10vol.%SiCp/AI-Si composites was lower than that of AI-Si matrix at 37$0^{\circ}C$. However at high temperature of 43$0^{\circ}C$, SiC particle promoted static softening, diminishing the dislocation density at the interface of AI-Si matrix and reinforcements, then this resulted in higher fractional softening in composites. Both of failure strain improved reducing the fracture of SiC particle and Si precipitates above 32$0^{\circ}C$, however at low temperature of 27$0^{\circ}C$, the softening effect by interrupted deformation was found to be negligible.

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AISI 304L 오오스테나이트 스테인레스 강 용접부 의 Low Cycle Fatigue 거동에 관한 연구 (Low Cycle Fatigue Behaviour of AISI 304L Austenitic Stainless Steel Weldment)

  • 김환태;황선효;남수우
    • Journal of Welding and Joining
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    • 제2권1호
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    • pp.49-57
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    • 1984
  • The influence of weld defect, residual stress and microstructure on the Low Cycle Fatigue(L. C. F.) behaviour of AISI 304L austenitic stainless steel weldment has been studied. The specimens were welded by shielded metal are welding process, post weld heat treated(PWHT) at 900.deg.C for 1.5hrs, and tested under total strain controlled condition at room temperature. The results of the experiment showed that weld defect affected the L.C.F. behaviour of weldment deleteriously compared to the residual stress or microstructure, and it reduced the L.C.F. life about 70-80%. The PWHT exhibited beneficial effect on the L.C.F. behaviour and increased the L.C.F. life about 120%. This enhancement by PWHT was attributed to the removal of residual stress and recovery of weld metal ductility. The cyclic stress flow of as welded specimens showed intermediate cyclic softening, whereas those of heat treated specimens showed continuous cyclic hardening, and this difference was explained in terms of the residual stress removal and dislocation behaviour. Scanning electron microscopy studies of fatigue fracture surface showed that weld defects of large size and near weld surface were detrimental to the L.C.F. behaviour of weldment.

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육계 출하 후 관리 (Handling of Harvested Broiler)

  • 김동훈;유영모;조수현;박범영;김용곤;이종문
    • 한국축산식품학회지
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    • 제24권4호
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    • pp.424-432
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    • 2004
  • The handling and transport of broiler birds from farm to the processing factory is known to cause injury and dead. The preslaughter period can be compromised through thermal stress, emotional stress, starvation, dehydration, metabolic exhaustion, trauma to the skin and bone fraction resulting in bruising and dead. This paper focuses on the control points of individual post Harvest stages by reference to recent literature. In catching, the injuries and deads are caused from fracture of bone, skin damage and hipbone dislocation. It can be improved by training the catchers. The primary factor of dead during transportation is from thermal stress. It is related to stocking density, type of crate and vehicle, ventilation and transportation time. Of the factors, the ventilation is very important. The holding place should be built with consideration of protection from the hostile external environment. There were not much progresses in this area, however, many researches are conducting to focus on animal welfare in European Union. Recently, it is rapidly changed in marketing custom from whole carcass to portion cut in Korea. This means the increase of economic loss due to the mishandling at post harvest. The systematic approach is demanded for this area.

OUT-OF-PILE MECHANICAL PERFORMANCE AND MICROSTRUCTURE OF RECRYSTALLIZED ZR-1.5 NB-O-S ALLOYS

  • Ko, S.;Lee, J.M.;Hong, S.I.
    • Nuclear Engineering and Technology
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    • 제43권5호
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    • pp.421-428
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    • 2011
  • The out-of-pile mechanical performance and microstructure of recrystallized Zr-1.5 Nb-S alloy was investigated. The strength of the recrystallized Zr-1.5Nb-O-S alloys was observed to increase with the addition of sulfur over a wide temperature range, from room temperature up to $300^{\circ}C$. A yield drop and stress serrations due to dynamic strain were observed at room temperature and $300^{\circ}C$. Wavy and curved dislocations and loosely knit tangles were observed after strained to 0.07 at room temperature, suggesting that cross slip is easier. At $300^{\circ}C$, however, dislocations were observed to be straight and aligned along the slip plane, suggesting that cross slip is rather difficult. At $300^{\circ}C$, oxygen atoms are likely to exert a drag force on moving dislocations, intensifying the dynamic strain aging effect. Oxygen atoms segregated at partial dislocations of a screw dislocation with the edge component may hinder the cross slip, resulting in the rather straight dislocations distributed on the major slip planes. Recrystallized Zr-Nb-S alloys exhibited ductile fracture surfaces, supporting the beneficial effect of sulfur in zirconium alloys. Oxidation resistance in air was also found to be improved with the addition of sulfur in Zr-1.5 Nb-O alloys.

고온-고압 수소 주입된 Fe-30Mn-0.2C-(1.5Al) 고망간강의 인장 거동에 미치는 표면 조건의 영향 (Effect of Surface Condition on Tensile Properties of Fe-30Mn-0.2C-(1.5Al) High-Manganese Steels Hydrogen-Charged Under High Temperature and Pressure)

  • 이승용;이상혁;황병철
    • 한국재료학회지
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    • 제27권6호
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    • pp.318-324
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    • 2017
  • In this study, two Fe-30Mn-0.2C-(1.5Al) high-manganese steels with different surface conditions were hydrogen-charged under high temperature and pressure; then, tensile testing was performed at room temperature in air. The yield strength of the 30Mn-0.2C specimen increased with decreasing surface roughness(achieved via polishing), but that of the 30Mn-0.2C-1.5Al specimen was hardly affected by the surface conditions. On the other hand, the tendency of hydrogen embrittlement of the two high-manganese steels was not sensitive to hydrogen charging or surface conditions from the standpoints of elongation and fracture behavior. Based on the EBSD analysis results, the small decrease in elongation of the charged specimens for the Fe-30Mn-0.2C-(1.5Al) high-manganese steels was attributed to the enhanced dislocation pile-up around grain boundaries, caused by hydrogen.

5052 알루미늄 합금 마찰교반접합부 특성에 미치는 접합인자의 영향 (Effect of Welding Parameters on the Friction Stir Weldability of 5052 Al alloy)

  • 이원배;김상원;이창용;연윤모;장웅성;서창제;정승부
    • Journal of Welding and Joining
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    • 제22권3호
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    • pp.69-76
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    • 2004
  • Effects of friction stir welding parameters such as tool rotation speed and welding speed on the joints properties of 5052 Al alloys were studied in this study. A wide range of friction stir welding conditions could be applied to join 5052 AA alloy without defects in the weld zone except for certain welding conditions with a lower heat input. Microstructures near the weld zone showed general weld structures such as stir zone (SZ), thermo-mechanically affected zone (TMAZ) and heat affected zone (HAZ). Each zone showed the dynamically recrystallized grain, transient grain and structure similar to base metal's, respectively. Hardness distribution near the weld zone represented a similar value of the base metal under wide welding conditions. However, in case of 800 rpm of tool rotation speed, hardness of the stir zone had a higher value due to the fine grain with lots of dislocation tangle, a higher angle grain boundary and some of Al3Fe particles. Except joints with weld defects, tensile strength and elongation of the joints had values similar to the base metal values and fracture always occurred in the regions approximately 5mm away from the weld center.

Cr-Mo강의 수소확산 특성에 관한 유한요소해석 (The Finite Element Analysis on the Characteristics of the Hydrogen Diffusion for the Cr-Mo Steels)

  • 이휘원;하민수
    • 한국기계기술학회지
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    • 제13권2호
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    • pp.115-121
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    • 2011
  • The size of hydrogen molecule is not so small as to invade into the lattice of material, and therefore, hydrogen invades into the material as atom. Hydrogen movement is done by diffusion or dislocation movement in the near crack tip or plastic deformation. Hydrogen appeared to have many effects on the mechanical properties of the Cr-Mo steel alloys. The materials for this study are 1.25Cr-0.5Mo and 2.25Cr-1Mo steels used at high temperature and pressure. The hydrogen amount obtained by theoretical calculation was almost same with the result solved by finite element analysis. The distribution of hydrogen concentration and average concentration was calculated for a flat specimen. Also, finite element analysis was employed to simulate the redistribution of hydrogen due to stress gradient. The calculation of hydrogen concentration diffused into the material by finite element method will provide the basis for the prediction of delayed fracture of notched specimen. The distribution of hydrogen concentration invaded into the smooth and notched specimen was obtained by finite element analysis. The hydrogen amount is much in smooth specimen and tends to concentrate in the vicinity of surface. Hydrogen embrittlement susceptibility of notched specimen after hydrogen charging is more remarkable than that of smooth specimen.

Total Ankylosis by Heterotopic Ossification in an Adolescent Anterior Trans-olecranon Fracture Dislocation: A Case Report

  • Kim, Beom-Soo;Song, Kwang-Soon;Bae, Ki-Cheor;Lee, Si-Wook;Um, Sang-Hyun;Cho, Chul-Hyun
    • Clinics in Shoulder and Elbow
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    • 제22권3호
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    • pp.154-158
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    • 2019
  • The incidence of heterotopic ossification in adolescents appears to be lower than in adults. There exist very few reports of heterotopic ossification with total bony ankylosis in child or adolescent populations. We describe a case of total bony ankylosis of the elbow secondary to heterotopic ossification, in a 14-year-old female. Total ankylosis of the elbow at 45 degrees of flexion was noted 6 months postsurgery, and complete surgical excision of the heterotopic mass was performed. After an additional one-time dose of radiation therapy and nonsteroidal anti-inflammatory drug medication, full range of motion was obtained without any recurrence or other complications, up to the last follow-up of 30 months.