• Title/Summary/Keyword: Stress added

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Evaluation of Intraoperative Stress Radiologic Tests for Syndesmotic Injuries (수술 중 부하 영상을 이용한 원위 경비 관절 손상 진단 방법의 평가)

  • Bae, Su-Young;Chung, Hyung-Jin;Oh, Su-Chan
    • Journal of Korean Foot and Ankle Society
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    • v.15 no.1
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    • pp.22-26
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    • 2011
  • Purpose: To report the effectiveness of adding distal fibular external rotation stress test on the traditional lateral stress Cotton test in evaluating distal tibiofibular syndesmotic injuries. Materials and Methods: We evaluated syndesmotic injuries with intraoperative stress test during treating ankle fractures from March 2009 to September 2010. External rotation of distal fibula using small elevator was added on traditional stress test in case of suspicious syndesmotic injury. We retrospectively reviewed and compared the results of each test in 44 cases for which we tried both tests. Results: In 9 cases of positive traditional lateral stress tests, positive results were obtained in all cases by additional external rotation tests. In 21 cases of negative traditional stress tests, additional stress tests results were also negative. But there were 10 cases of positive additional tests and 4 of negative additional tests in equivocal results cases by the traditional stress tests. Conclusion: Using additional external rotation stress test in case of equivocal test result by the traditional lateral stress Cotton test for evaluation of syndesmotic injury during operation for ankle fracture can be a supplemental method to clarify syndesmotic injury needs fixation.

Effect of Baechu Kimchi Added Ecklonia cava Extracts on High Glucose-induced Oxidative Stress in Human Umbilical Vein Endothelial Cells

  • Lee, Hyun-Ah;Song, Yeong-Ok;Jang, Mi-Soon;Han, Ji-Sook
    • Preventive Nutrition and Food Science
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    • v.19 no.3
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    • pp.170-177
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    • 2014
  • Endothelial cell dysfunction is considered to be a major cause of vascular complications in diabetes. In the present study, we investigated the protective effect of a baechu kimchi added Ecklonia cava extract (BKE) against high glucose induced oxidative damage in human umbilical vein endothelial cells (HUVECs). Treatment with a high concentration of glucose (30 mM) induced cytotoxicity, whereas treatment with BKE protected HUVECs from high glucose induced damage; by restoring cell viability. In addition, BKE reduced lipid peroxidation, intracellular reactive oxygen species and nitric oxide levels in a dose dependent manner. Treatment with high glucose concentrations also induced the overexpression of inducible nitric oxide synthase, cyclooxygenase-2 and NF-${\kappa}B$ proteins in HUVECs, but BKE treatment significantly reduced the overexpression of these proteins. These findings indicate that BKE may be a valuable treatment against high glucose-induced oxidative stress HUVECs.

Erosion properties of plasma sprayed zirconia Based coatings (지르코니아계 용사 코팅층의 Erosion 특성)

  • 신종한;임상규;임대순
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.346-353
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    • 2001
  • Zirconia powder containing 3 mol% yttria(3Y-PSZ) with and with out Fe$_2$O$_3$ addition was coated on tile cast iron substrate by plasma spraying method. The erosion experiments were performed at temperatures from $25^{\circ}C$ to $600^{\circ}C$. A gas blast type erosion tester was used to examine erosion behavior of the specimens. The results of 3Y-PSZ coatings showed that tile erosion rate had maximum value at 40$0^{\circ}C$. It coincided with tile results of phase transformation tetragonal phase to monoclinic phase caused by low temperature thermal degradation. The tensile stress relaxation and the micro-hardness improvement significantly influenced on the erosion rate at $600^{\circ}C$. In the case of Fe$_2$O$_3$ added 3Y-PSZ coatings, the erosion rate of tested at $25^{\circ}C$ showed maximum value at 5.0 mol% Fe$_2$O$_3$ added coating. This tendency is caused by the improvement of mechanical properties and the tensile residual stress. The erosion rate at 200'c and 400'L showed significantly decrease by Fe203 addition. This decrease is believed to be the stabilization of the tetragonal phase and the increase of micro-hardness.

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Improved Cell Viability of Lactobacillus crispatus KLB46 by Stress Adaptation (Lactobacillus crispatus KLB46의 스트레스 전처리시 열 내성 증진효과)

  • Kwak, Dae-Yung;Kang, Chang-Ho;Jeon, HanEul;So, Jae-Seong
    • KSBB Journal
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    • v.29 no.2
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    • pp.81-86
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    • 2014
  • Lactobacilli, the dominant species of microorganisms in the vaginal flora of healthy women, play important roles to prevent bacterial vaginosis and other sexually transmitted diseases. In this study, we carried out studies on stress adaptation prior to various stress treatment. We found that heat or salt adapted KLB46 showed higher cell viability than non adapted upon heat stress at $60^{\circ}C$ for 20 min. When chloramphenicol was added during the adaptation process, heat tolerance was abolished. This result suggested that de novo protein synthesis was essential during adaptation.

Parenting Stress and Marital Satisfaction among Dual-earner Families (맞벌이가족의 부모역할 긴장과 부부관계)

  • 정현숙
    • Journal of the Korean Home Economics Association
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    • v.35 no.5
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    • pp.151-162
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    • 1997
  • The purpose of this study was to examine the impacts of various stressors among dual-earner families on parenting stress and marital satisfaction. Using a survey data collected from 168 dual-earner couples, this study investigated impact of various stressors, including husband division of labor, the satisfaction of childcare arrangement, husband's support on wife's outside work, family socioeconomic status, and strains from job. The finding suggested that, after controlling background variables(length of marriage, the number of children, and family income), high husbands' support on wife's outside work and low strains about their work hours had influenced on higher parenting stress among fathers, while high strains about their work hours had related to high parenting stress among mothers. It also found that high satisfaction on childcare arrangement and low depression were the factors predicting higher marital satisfaction of mothers, and high support on their wife's outside work, low work role strain, low depression, and low parenting stress had influenced on higher marital satisfaction among fathers. Discussions and recommendations for future research were added.

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Effect of Weld Residual Stress on Fatigue Analysis of Nozzle (노즐의 피로해석에 미치는 용접잔류응력의 영향)

  • Kim, Sang-Chul;Kim, Man-Won
    • Journal of Welding and Joining
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    • v.32 no.1
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    • pp.71-78
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    • 2014
  • Although the fatigue design curve of ASME Code has enough margin with respect to alternating stress and cycles, the welding residual stress(WRS) should be included in fatigue analysis. In this paper, WRS distribution in a nozzle with dissimilar metal weldment was obtained by finite element analysis and was added in fatigue analysis. The fatigue analysis was performed by following the ASME Code including thermal and stress analysis applying with postulated 30 transient conditions. The calculated results of a cumulative fatigue usage factors(CUF) were compared for the case of the models with or without WRS effects. The results showed that the CUF at weldment and heat affected zone was affected by the WRS.

EMG Signal Elimination Using Enhanced SVD Filter in Multi-Lead ECG (향상된 SVD 필터를 이용한 Multi-lead ECG에서의 EMG 신호 제거)

  • Park, Kwang-Li;Park, Se-Jin;Choi, Ho-Sun;Jeong, Kee-Sam;Lee, Kyoung-Joung;Yoon, Hyoung-Ro
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.6
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    • pp.302-308
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    • 2001
  • SVD(Singular Value Decomposition) filter for the suppression of EMG in multi-lead stress ECG is studied. SVD filter consists of two parts. In the first part, the basis vectors were chosen from the averaged singular vectors obtained from the decomposed noise-free ECG. The singular vector is computed from the stress ECG and is compared itself with basis vectors to know whether the noise exist in stress ECG. In the second part, the existing elimination method is used, when one(or two) channels is(or are) contaminated by noise. But the proposed enhanced SVD filter is used in case of having the noise in the many channels. During signal decomposition and reconstruction, the noise-free channel or the least noisy channel have the weight of 1, the next less noisy channel has the weight of 0.8. In this way, every channel was weighted by decreased of 0.2 in proportion to the amount of the added noise. For the evaluation of the proposed enhanced SVD filter, we compared the SNR computed by the enhanced SVD filter with the standard average filter for the noise-free signal added with artificial noise and the patient data. The proposed SVD filter showed better in the SNR than the standard average filter. In conclusion, we could find that the enhanced SVD filter is more proper in processing multi-lead stress ECG.

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Torsion of circular open cross-section with corrugated inner and outer surface

  • Pala, Yasar;Pala, Abdullah
    • Structural Engineering and Mechanics
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    • v.73 no.1
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    • pp.75-82
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    • 2020
  • In this study, the problem of torsion of bars with open cross section surrounded by corrugated boundaries is analyzed. An approximate analytical solution is given using perturbation technique. First, the stress analysis for circular open cross-section for arbitrary opening angle is formulated and the problem is analytically solved. Second, the open cross-section with corrugated cross section is analyzed using perturbation method. First order contributions to the stresses and the torques have been added. The results have been exemplified and compared by considering special examples.

Effect of Melting Pool on the Residual Stress of Welded Structures in Finite Element Analysis

  • Lee, Jang-Hyun;Hwang, Se-Yun;Yang, Yong-Sik
    • Journal of Ship and Ocean Technology
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    • v.11 no.3
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    • pp.14-23
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    • 2007
  • Welding processes cause undesirable problems, such as residual stresses and deformations due to the thermal loads imposed by local heating, melting, and cooling processes. This paper presents a computational modeling technique to simulate the Gas Metal Arc Welding (GMAW) process, emphasizing the effect of the melting bead on the residual stress distribution. Both a three-bar analogy and a three-dimensional thermo-mechanical finite element analysis are carried out in order to explain the effect. Element (de)activation, enthalpy, and adjustment of the reference temperature of thermal strain are considered with respect to the effect of the weld filler metal added to the base metal during a thermo-elastic-plastic analysis. Stress distributions obtained by the present study are compared with measured values and available data from other studies. The effect of the melting bead on the residual stress distribution is discussed and demonstrated.

Static assessment of quadratic hybrid plane stress element using non-conforming displacement modes and modified shape functions

  • Chun, Kyoung-Sik;Kassegne, Samuel Kinde;Park, Won-Tae
    • Structural Engineering and Mechanics
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    • v.29 no.6
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    • pp.643-658
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    • 2008
  • In this paper, we present a quadratic element model based on non-conforming displacement modes and modified shape functions. This new and refined 8-node hybrid stress plane element consists of two additional non-conforming modes that are added to the translational degree of freedom to improve the behavior of a membrane component. Further, the modification of the shape functions through quadratic polynomials in x-y coordinates enables retaining reasonable accuracy even when the element becomes considerably distorted. To establish its accuracy and efficiency, the element is compared with existing elements and - over a wide range of mesh distortions - it is demonstrated to be exceptionally accurate in predicting displacements and stresses.