• 제목/요약/키워드: cause of stress

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사출금형에서 내압에 의한 응력집중 및 크랙 분석 (An Analysis of stress concentration and crack in injection mold by cavity pressure)

  • 최성현;황수진;최성주;류민영
    • 한국금형공학회:학술대회논문집
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    • 한국금형공학회 2008년도 하계 학술대회
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    • pp.159-162
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    • 2008
  • High pressure is involved during injection molding operation specially packing phase. Cracks in the mold are often occurred by high cavity pressure. In this study, structural analysis of mold has been performed using commercial softwares, Abaqus and Ansys, to investigate cause of crack in the injection mold. Structural analysis contains four cases: stress distribution according to the cavity pressure, stress concentration according to the boundary conditions, stress concentration for inter-locking design of mold, and stress concentration for distributed cavity pressure. Through this study it was observed that the locations of stress concentrations were coincident with locations of crack. Robust mold design is being required to withstand high cavity pressure.

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청년기환자의 입원생활에 따르는 긴장에 관한 연구 (Study on the Adolescent Patient′s Stress during Hospitalization)

  • 백영주
    • 대한간호학회지
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    • 제6권1호
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    • pp.72-79
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    • 1976
  • Contemper nursing literature place much importance on human- centered and individualized care. Nursing research has related stress during hospitalization of adolescent patients to adaptation to a new environment, isolation from friends, limitation due to illness, over protection of parents and communication with member of the medical team. The investigator conducted this study in the hope that an understanding of adolescents responses to hospitalization, their perceptions, the kinds and levels of stress, and the relationships between stressors and individual characteristics would contribute to the improvement of adolescent patient care. The objective of the study was to obtain informations related to the adolescents psychological stress experience during hospitalization, specifically stress from interpersonal relationships and communication, isolation from the family, social or economic problems, illness and from the treatment environment and nursing care. An interview schedule adopted from Holmes and Rahe's Social Readjustment Rating Scale and selected items from Voicer's instrument on stress-producing events was used with 120 adolescent inpatients aged 13 to 18 years three general hospitals in Seoul during Aug. 10, to Sep. 30, 1975. 1. The sample consisted of 66 male and 54 female patients. Sixty-six percent were late adolescents, aged 16 to 18 years: 4% were early adolescents, aged 13 to 15 years. The primary cause for hospitalization was for orthopedic problems (35.8%). More than half of these (54.4%) were due to injury or accident. 2. Stress eclated to illness revealed the highest score (4.97), followed by stress related to treatment environment and nursing care (4.34) , isolation from family and social or economic problems (4.01) and interpersonal relationships and communication (3.96). 3. The perceived indifference of doctors and nurses was a serious cause of stress (mean=4.83). Fellow patients and visitors caused least stress (mean=2.06). 4. Discontinuation of education or unemployment were major stressful events (mean=4.71). Least stressful was isolation from the family (mean=3.47). 5. More than 94% of the respondents expressed fears related to body image (mean=4.97) 6. Within the category of treatment environment and nursing care, items related to restrictions because of treatment, discomfort because of treatment, inadequate explanation from nurses about procedures were rated as severe stress events (mean=4.6). Items related to the ward environment and to having a relative stay with them were seen by the group as less serious events (mean=3.7). 7. Stress related to interpersonal relationships and communication was correlated positively with female patients and those preferring passive activities. (P〈0.05) 8. Stress related to family problems was positively related to female and early adolescent patients (P< 0.05). Stress related to social problems was positively , elated to students and those preferring active pursuits (P< 0.05). 9. There were no correlation between the high stress related to disease and any of the characteristic items. (P> 0.05) 10. Stress related to treatment environment and nursing care was positively related of early adolescent and female and student patients. (P< 0.05) This group of hospitalized adolescents reported high level of stress related to treatment environment and nursing care, due to lack of consideration of normal growth and development and individual characteristics. The findings have important implications for the planning of effective, individualized, comprehensive nursing care of adolescents during hospitalization.

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Relationships Between Cause of Cancer and Breast Cancer-Related Factors in Breast Cancer Survivors

  • Wang, Hsiu-Ho;Chung, Ue-Lin
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권8호
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    • pp.3889-3892
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    • 2012
  • Aims: The purposes of this study were to (1) to identify the causes of cancer in breast cancer survivors in Taiwan; and (2) to investigate the influence of demographic characteristics and breast cancer-related factors on the cause of cancer. Materials and method: This study details the related investigative results on survivors with breast cancer using a descriptive and correlational design. A convenience sampling approach was employed. A structured questionnaire was used to assess the participants. Results: A total of 230 breast cancer survivors completed the questionnaire. Low-scoring cause of cancer participants were older adults (OR = 2.49, p<0.05) who were already of menopausal status (OR = 2.28, p < 0.05). Around 72% of particpants agreed high responsibility. Our breast cancer survivors felt stress had caused their breast cancer. Conclusion: These findings are helpful in understanding the relationship between cause of cancer and related factors in breast cancer survivors.

한의학적(韓醫學的) 홧병 치료에 따라 나타나는 홧병 환자의 스트레스지각 정도와 임상양상(臨床樣相)의 변화에 대한 비교연구(比較硏究) (A comparative study on the changes of the clinical appearances and stress perception of Hwabyung patients, according to the oriental medical therapy)

  • 임재환;김종우
    • 동의신경정신과학회지
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    • 제11권1호
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    • pp.47-57
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    • 2000
  • This study was designed and performed to identify the effects of oriental medical therapy on hwabyung patients by investigating the life events as the cause of Hwabyung, recent stress perception which influences the clinical appearances and change of symptoms by means of objective scales. 1. Through life events rating scale, life events are reported as follows, in the order of majority. Health, discord within family, martial life, friendship and interest, religion etc. Hwabyung patients experienced negative stress much more than positive stress. 2. Through the GARS (Global Assessment of Recent Stress), there were some significant decreases of stress perception in stress4(stress of sickness or injury), stress7(stress of change or no change in routine) and stress8(overall global stress)(p<0.05, respectively), but there were no significant decreases in five items out of eight items. 3. There were significant decreases of all rated symptoms(feeling of chest oppressed, stuffy in the chest or epigastric mass, feeling of something pushing-up, flushing of body or face, abrupt impulsion of anger, resentment), which were checked weekly for 4 times (p<0.05, respectively). In this study the symptoms of hwabyung were improved regardless of stress perception. It means that hwabyung can be improved significantly with oriental medical therapy.

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Relationship between sweet food intake and stress among college students in Seoul and Gyeonggi areas

  • Kim, Jun-Gyeong;Lee, Jounghee;Song, Kyunghee
    • Journal of Nutrition and Health
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    • 제54권4호
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    • pp.373-382
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    • 2021
  • Purpose: For college students, poor eating habits can cause problems with adult health. This study investigated the status of sweet food intake and the degree of stress in college students in the Seoul and Gyeonggi areas to provide a basis for nutrition education by analyzing the relationship between stress and sugar intake. Methods: The subjects were 760 college students, and the survey was conducted using a questionnaire. Statistical analysis for collected data was performed using SPSS (version 21.0). Results: The stress score showed higher stress in female students. Females had more stress in their employment and study-related problems than males. For changes in food intake under stress, the intake was increased greatly in females than in males. For food preference changes before and after stress, males preferred more spicy foods and less salty foods after stress. After stress, females significantly preferred sweeter and spicier foods and less salty, sour, and bitter foods. The intake of sweet foods by stress factors showed that the intake of snacks was higher under the condition of 'worry, fatigue, and tension', and the intake of beverages was increased significantly under the condition of 'anger and aggression'. Conclusion: Sweet foods were preferred under stress, and the amount of intake was increased. Education on food selection and nutrition information should be provided to prevent health problems that can be developed by the reckless intake of sweet foods. Active guidance is needed for college students to select the proper snacks instead of nutritionally insufficient foods to relieve stress.

가속된 열적 스트레스에 의한 PAI / Nano Silica 하이브리드 코일의 절연수명 추정 (Estimation of Insulation Life of PAI/Nano Silica Hybrid Coil by Accelerated Thermal Stress)

  • 박재준
    • 전기학회논문지
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    • 제68권1호
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    • pp.52-60
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    • 2019
  • In this paper, four types of insulation coils were fabricated by adding various kinds of glycols to improve the flexibility and adhesion of insulating coils in varnish dispersed with PAI / Nano Silica_15wt%. The applied voltage and frequency were 1.5 kV / 20 kHz for accelerated life evaluation. Through the 6th temperature stress level, the cause of the insulation breakdown of the coil was ignored and only the breakdown time was measured. The Arrhenius model was chosen based on the theoretical relationship between chemical reaction rate and temperature for estimating the insulation life of the coil due to accelerated thermal stress. Three types of distributions (Weibull, Lognormal, Exponential) were selected as the relationship between thermal stress model and distribution. The average insulation lifetime was estimated under the temperature stress of four types of insulation coils through the relationship between one kind of model and three kinds of distributions.

재하방법에 따른 사질토 지반의 연직응력 특성 (Characteristic of Vertical Stress in Sandy Soil according to Loading Types)

  • 남효석;이상호;권무남
    • 한국농공학회논문집
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    • 제51권6호
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    • pp.83-90
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    • 2009
  • This study was carried out to evaluate the vertical stress properties in sandy soil according to changes of loading type in soil bin compacted three layers. The following conclusions and comparisons have been made based on careful analysis from theoretical and experimental methods. : When sandy soil subjected to cycle-loading, compression of foundation and diffusion of vertical stress increment(${\Delta}{\sigma}_2$) were influenced by magnitude of loading plate. When sandy soil subjected to reloading after removing of pre-loading, the distribution of ${\Delta}{\sigma}_2$ depth at one time of loading plate width was different from its distribution at more deep point cause of load hysteresis, so in case of design of structure, the effect of ${\Delta}{\sigma}_2$ as depth must be considered. The increment of vertical stress will be different as loading condition and foundation depth, the loading condition must be considered in case of structure design.

차륜/래일 접촉에 의한 차륜의 잔류응력 평가 (Evaluation of Residual Stress of railway wheel)

  • 서정원;구병춘;정흥채
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2003년도 춘계학술대회 논문집
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    • pp.668-673
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    • 2003
  • A wheel and axle failure can cause a derailment with its attendant loss of life and property. The service conditions of railway vehicles have become severe in recent years due to a general increase in operating speeds. Damages of railway wheel are a spalling by wheel/rail contact and thermal crack by braking heat etc. One of the main source of damage is a residual stress. therefore it is important to evaluate exactly. A Residual stress of wheel is formed at the process of heat treatment when manufacturing. it is changed by contact stress developed by wheel/rail contact. Distributions of residual stress vary according to a magnitude of wheel load, a magnitude of friction when acceleration and deceleration. The objective of this paper is to estimate the influence of wheel motion on the residual stress distribution in the vicinity of the running surface.

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Simplified approach for the evaluation of critical stresses in concrete pavement

  • Vishwakarma, Rameshwar J.;Ingle, Ramakant K.
    • Structural Engineering and Mechanics
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    • 제61권3호
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    • pp.389-396
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    • 2017
  • Concrete pavements are subjected to traffic and environmental loadings. Repetitive type of such loading cause fatigue distress which leads to failure by forming cracks in pavement. Fatigue life of concrete pavement is calculated from the stress ratio (i.e. the ratio of applied flexural stress to the flexural strength of concrete). For the correct estimation of fatigue life, it is necessary to determine the maximum flexural tensile stress developed for practical loading conditions. Portland cement association PCA (1984) and Indian road congress IRC 58 (2015) has given charts and tables to determine maximum edge stresses for particular loading and subgrade conditions. It is difficult to determine maximum stresses for intermediate loading and subgrade conditions. The main purpose of this study is to simplify the analysis of rigid pavement without compromising the accuracy. Equations proposed for determination of maximum flexural tensile stress of pavement are verified by finite element analysis.

Effects of stress on scuticociliate killing activity of olive flounder (Paralichthys olivaceus) plasma in relation to humoral immunity

  • Kwon, Se-Ryun;Kim, Chun-Soo;Kim, Ki-Hong
    • 한국어병학회지
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    • 제15권2호
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    • pp.77-82
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    • 2002
  • Effects of stress-induced suppression of humoral immunity on scuticociliate killing activity of olive flounder plasma were investigated. Changes in glucose level. alternative complement activity and Iysozyme activity of plasma by handling stress were analysed in relation to in vitri parasiticidal activity of plasma. The plasma glucose level was about two times higher in fish after a handling stress than in control fish. Plasma lysozyme activity and natural haemolytic activity were decreased in suessed fish.The scuticociliate killing activity of plasma was significantly lower in stressed fish than in non-stressed control fish. The present results indicated that stress-induced immunodepression could be a cause of scuticociliatosis occurrence in olive flounder.