• Title/Summary/Keyword: primary stress

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Stress Analysis and Evaluation of Steam Separator of Heat Recovery Steam Generator (HRSG) (배열회수보일러 기수분리기의 응력해석 및 평가)

  • Lee, Boo-Youn
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.4
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    • pp.23-31
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    • 2018
  • Stress of a steam separator, equipment of the high-pressure (HP) evaporator for a HRSG, was analyzed and evaluated according to ASME Boiler & Pressure Vessel Code Section VIII Division 2. First, from the analysis results of the piping system model of the HP evaporator, reaction forces of the riser tubes connected to the steam separator, i.e., nozzle loads, were derived. Next, a finite element model of the steam separator was constructed and analyzed for the design pressure and the nozzle loads. The results show that the maximum stress occurred at the bore of the riser nozzle. The primary membrane stresses at the shell and nozzle were found to be less than the allowable stress. Next, the steam separator was analyzed for the steady-state operating conditions of operating pressure, operating temperature, and nozzle loads. The maximum stress occurred at the bore of the riser nozzle. The primary plus secondary membrane plus bending stress at the shell and nozzle was found to be less than the allowable stress.

Factors Influencing Stress Appraisal of Cancer Patients' Primary Caregivers (암환자의 일차간호제공가족의 스트레스 인지평가 영향 요인 분석)

  • Shin, Gye-Young;Kim, Mae-Ja
    • Korean Journal of Adult Nursing
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    • v.14 no.1
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    • pp.125-134
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    • 2002
  • Purpose: The objectives for this study were to identify the factors that correlate with appraisal of illness and to explore what variables are predictive of cancer patients primary caregivers' cognitive appraisal for stress. Method: The subjects were selected by convenient sampling and 130 caregivers who completed a questionnaire. Measures used in this study included the Family Inventory of Resources for Management, Social Support Index, Family Crisis Oriented Personal Evaluation Scales and Family Coping Coherence Index. Pearson correlation was used to identify the relationship among factors and multiple regression was used to determine the individual and cumulative effect of potential predictors on the caregivers' appraisal. Results: Patient's level of activity, severity of the disease, quality of relation between patient and caregiver, caregiver's subjective health status, economic status, family resources and coping were significantly correlated. Among the variables, coping, family resources, economic status and quality of relation between caregiver and patient predicted 49.2 percent of the variance in appraisal of caregivers' stress condition. Conclusion: These findings suggest that coping mechanisms and family resources are important for positive appraisal. Nurses should provide adequate nursing care for the primary caregiver about professional care information and supportive counseling.

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PWSCC growth rate model of alloy 690 for head penetration nozzles of Korean PWRs

  • Kim, Sung-Woo;Eom, Ki-Hyun;Lim, Yun-Soo;Kim, Dong-Jin
    • Nuclear Engineering and Technology
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    • v.51 no.4
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    • pp.1060-1068
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    • 2019
  • This work aims to establish a model of a primary water stress corrosion crack growth rate of Alloy 690 material for the head penetration nozzles of Korean pressurized water reactors. The test material had an inhomogeneous microstructure with bands of fine-grains and intragranular carbides in the matrix of coarse-grains, which was similar to the archive materials of the head penetration nozzles. The crack growth rate was measured from the strain-hardened materials as a function of the stress intensity factor in simulated primary water at various temperatures and dissolved hydrogen contents. The effects of strain-hardening, temperature, and dissolved hydrogen on the crack growth rate were analyzed independently, and were then introduced as normalizing factors in the crack growth rate model. The crack growth rate model proposed in this work provides a key element of the tools needed to assess the progress of a stress corrosion crack when detected in thick-wall Alloy 690 components in Korean reactors.

The Study Of Parenting Stress, Social support, Coping, Parental behavior In Partial Caregiving-Grandmothers -Comparing with Caregiving-mothers- (지원 양육조모의 양육 스트레스, 사회적 지지, 대처, 양육 행동에 대한 연구 -주 양육모, 부분 양육모와의 비교를 중심으로-)

  • Lee, Ji Yeon;Kim, Won-Kyung;Chung, Kyong-Mee
    • 한국노년학
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    • v.29 no.2
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    • pp.441-458
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    • 2009
  • The present study compared the differences in mechanisms of caregiving stress, depression, parenting behaviors, stress-coping, and social support between caregiving grandmothers and the caregiving mothers. Three caregiving groups were compared; One hundred and fifty-two grandmothers rearing their grandchild as daytime care-giver (partial caregiving-grandmother group), 152 mothers who shared the responsibilities of caregiving the same child (partial caregiving-mother group), and another 157 mothers who rear their child as daytime care-giver (primary caregiving-mother group). Predictors of parental stress for these caregiving groups were also assessed. The results indicated that partial caregiving-grandmother group had more depressed than two mother groups, but there were no differences in parental stress among three caregiving groups. In addition, primary caregiving-mothers used more problem-focused coping strategies, and more social support than did partial caregiving-grandmothers. In parental behaviors, partial caregiving-grandmothers significantly had more laxness, less overactive than two mother groups. In the analysis of hierarchical regression, overactivity and depression were significant predictors of parental stress in partial caregiving-grandmothers. On the other hand, depression, social support, and overactivity were significant predictors of parental stress in partial caregiving-mothers. In primary caregiving-mothers, overactivity, depression, and emotion-focused coping were significant predictors of parental stress. We discussed the differences of the predictors in parental stress between grandmothers and mothers.

THE STUDY ON THE IMPLANT GEOMETRY (3종의 임프란트 형태에 관한 연구)

  • Lee, Yong-Chan
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.18 no.2
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    • pp.245-252
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    • 1996
  • The purpose of this study was to develop the implant which has superior stress distribution and primary stability to others by using Instron test and finite element method. The model used in the experiment were cylinder type implant, tapered screw type implant, screw type implants. Recognizing that the number of samples were small and the lack of applying press-fit conditions to the cylinder type, we can make the following conclusions.

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Primary Caregivers' Self-Efficacy and Stress Coping Strategy According to Home Care Nurses' Communication Styles (가정전문간호사의 의사소통 유형에 따른 주돌봄자의 자기효능감과 스트레스 대처방식)

  • Kim, Myo Sun;Jun, Eun-Young
    • Journal of Home Health Care Nursing
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    • v.26 no.2
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    • pp.219-229
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    • 2019
  • Purpose: This study aimed to investigate the difference between primary caregivers' self-efficacy and coping strategy according to the communication styles of home care nurses. Methods: Data were collected from 123 primary caregivers of patients who were registered at a home care nursing center in D city and who had been receiving home care for more than 3 months from January 1 to February 27, 2018. The questionnaire included items on communication style, self-efficacy, and stress coping strategy. The data were analyzed using descriptive statistics, t-test, and ANOVA. Results: Regarding primary caregivers' self-efficacy in terms of communication style, the caregivers showed higher efficacy in providing informative and friendly communication (F=14.07, p=.001). Regarding home care nurses' communication style and the stress coping strategy of the primary caregivers, the informative-friendly communication style was adopted the most for the problem-solving coping strategy (F=7.17, p=.001). Regarding the social support-seeking coping, home care nurses' friendly communication style was the most adopted (F=4.40, p=.014). Conclusion: This study suggests that home care nurses will plan to provide informative and friendly communication-oriented nursing care, and to improve self-efficacy and positively influence the coping method by using the communication styles appropriate to the state of the primary caregiver.

Efficacy of Commiphora myrrha and Honey in Primary Dysmenorrhea: A Randomized Controlled Study

  • Aneesa K, Haleema;Roqaiya, Mariyam;Quadri, Mohd Aqil
    • CELLMED
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    • v.11 no.4
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    • pp.19.1-19.8
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    • 2021
  • Background: Dysmenorrhea is the most common menstrual complaint in young women with a prevalence as high as 90% and is responsible for substantial repeated short-term absenteeism from school and work in young women. The objective of this study was to compare the efficacy of Commiphora myrrha and honey with mefenamic acid in primary dysmenorrhea. Materials and Methods: This prospective standard controlled trial was conducted at Luqman Unani Medical College Hospital and Research Center Vijayapura, India where 40 diagnosed patients of primary dysmenorrhea were randomly assigned to receive test drug (powdered Commiphora myrrha gum resin10g with 30g honey in two divided doses) or active control drug (mefenamic acid 250mg TID) for first 3days of menstruationfor two consecutive cycles. The primary outcome measure was reduction in severity of pain assessed by numerical pain rating scale (NPRS), and secondary outcome measures were improvement in quality of life (QOL) assessed by SF-36 and reduction in perceived stress score (PSS). Results: During first cycle treatment no significant difference was found in NPRS score (p=0.085) between the groups however significant difference in NPRS score (p<0.001) was seen during 2nd treatment cycle. Significant reduction (p=0.022) in the perceived stress score was noted and overall quality of life was markedly improved after treatment in both the groups. Conclusion: These data suggest that Commiphora myrrha gum resin with honey is an effective herb in reducing symptoms of primary dysmenorrhea. These results need to be confirmed by a properly designed trial with a larger sample size. Trial registration: Clinical Trial Registry India CTRI/2017/09/009596.

Analysis of Cold Workability at the A16061 Bulk Material by Tension and Compression Tests (Al 6061 Bulk재에서 인장 및 압축 시험에 의한 상온 가공성 비교 분석)

  • 김국주;박종수
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.74-79
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    • 2003
  • When workability at the a certain bulk deformation process is defined as the maximum plastic deformation capability that the workpiece can sustain without causing any cracks or fracture, the workability is dependent on the microstructure, initial workpiece shape, stress state developed during the deformation process, strain rata and presence of the interfacial friction between workpiece and tool. For a review purpose, the workability definition and test methods are summarized depending on the applied stress state at bulk deformation process in Table 1 at the text. In this study, the cold workabilities of as-cast A16061 bulk material have been measured and comparatively analyzed at the primary tensile stress state by using tensile specimens, the primary compressive stress state by using cylindrical specimens, and the forming limit diagram by ductile fracture.

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Multiaxial ratcheting behavior of Inconel 718 at elevated temperature (Inconel 718 의 고온 다축피로하중 하에서의 라체팅 거동)

  • Kim, Hyo-Shin;Kim, Kwang-Soo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.344-349
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    • 2008
  • Ratcheting behavior of IN 718 was investigated at $649^{\circ}C$ under various proportional and non-proportional loading conditions with stress control. The material response was initially elastic but substantial plastic strain was developed as the material softened cyclically. Ratcheting strain was measured to near fatigue life, and is found to have three stages of development - primary, secondary (steady-state) and tertiary. The secondary stage dominates for most cases. Under the same equivalent stress amplitude and mean stress, it was revealed that circular path loading gives higher ratcheting rates and shorter lives than linear paths and that the more ratcheting occurs when the cyclic load is in the same direction as the mean stress. The ratcheting strain at failure depends not only on its rate but also on fatigue life itself, and it is not a primary life-determining factor.

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Intonational Realization and Perception of English Noun Phrases and Compound Nouns (영어 명사구와 복합명사의 억양 실현 양상과 지각)

  • Kang, Sun-Mi;Kim, Mi-Hye;Jeon, Yoon-Shil;Kim, Kee-Ho
    • Speech Sciences
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    • v.12 no.4
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    • pp.153-166
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    • 2005
  • This paper attempts to examine the accent implementation and perception of noun phrases and compound nouns in English sentences, arguing that primary stress of noun phrase and compound noun is realized in relative prominence in intonation. The production test examines how the stress patterns of the noun phrases and compound nouns are realized in intonation of the English native speakers' utterances. The perception test investigates English and Korean listeners' comprehension of the intonation of the noun phrases and compound nouns. And the results of this experimental study show that speakers and listeners produce and perceive the primary stress as a relatively prominent accent even if in contrast of English listeners, Korean learners have difficulty in using the cue of pitch accent location and figuring out compound nouns and noun phrases.

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