• 제목/요약/키워드: Stress RAO

검색결과 67건 처리시간 0.028초

SPH Modeling of Hydraulics and Erosion of HPTRM Levee

  • Li, Lin;Rao, Xin;Amini, Farshad;Tang, Hongwu
    • Journal of Advanced Research in Ocean Engineering
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    • 제1권1호
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    • pp.1-13
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    • 2015
  • Post-Katrina investigations revealed that most earthen levee damage occurred on the levee crest and landward-side slope as a result of either wave overtopping, storm surge overflow, or a combination of both. In this paper, combined wave overtopping and storm surge overflow of a levee embankment strengthened with high performance turf reinforcement mat (HPTRM) system was studied in a purely Lagrangian and meshless approach, two-dimensional smoothed particle hydrodynamics (SPH) model. After the SPH model is calibrated with full-scale overtopping test results, the overtopping discharge, flow thickness, flow velocity, average overtopping velocity, shear stress, and soil erosion rate are calculated. New equations are developed for average overtopping discharge. The shear stresses on landward-side slope are calculated and the characteristics of soil loss are given. Equations are also provided to estimate soil loss rate. The range of the application of these equations is discussed.

거주지역별 노인의 자살생각과 관련요인 - 도시와 농촌의 비교 - (Suicidal Ideation and Associated Factors of the Elderly According to Residence Area - Focusing on the Comparisons between Urban and Rural Areas -)

  • 문영희;임미영
    • 한국보건간호학회지
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    • 제27권3호
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    • pp.551-563
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    • 2013
  • Purpose: This study was conducted in order to investigate the incidence and associated factors of suicidal ideation among the elderly according to residence area. Methods: This cross-sectional study used secondary data from the 2011 Korean National Health and Nutrition Examination Survey (KNHANES V-2). A representative sample of 1,464 men and women aged 65 and over was selected. Rao-scott $X^2$-test, multiple logistic regression models based on sampling scheme of the data were used. Results: Of the 1,464 respondents, 22.4% had experienced suicidal ideation during the past year. Higher incidence of suicidal ideation was observed in rural seniors (23.7%) than in urban seniors (21.1%). The incidence of suicidal ideation showed correlation with age, education level, depression, stress, lying in a sick bed, and current smoking status among elderly living in urban areas. However, among elderly living in rural areas, the incidence of suicidal ideation showed correlation with household income, depression, stress, and daily activity. Conclusion: Based on the results, nurses should manage effective and individualized nursing interventions for elders in planning suicide prevention programs with consideration for residence areas, because there were differences in the factors affecting suicidal ideation among elders according to residence area.

Action of Asparagus racemosus Against Streptozotocin-Induced Oxidative Stress

  • Govindarajan, Raghavan;Vijayakumar, Madhavan;Rao, Chandana Venkateshwara;Kumar, Vivek;Rawat, Ajay Kumar Singh;Pushpangadan, Palpu
    • Natural Product Sciences
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    • 제10권4호
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    • pp.177-181
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    • 2004
  • Antidiabetic treatment with tubers of Asparagus racemosus (Liliaceae) extract (l00 and 250 mg/kg body weight) for three weeks showed significant reduction in thiobarbituric acid reactive substances (TBARS) and glutathione reductase (GSH-R) in both liver and kidney. The treatment with A. racemosus significantly altered the glutathione (GSH) and GSH-R to be comparable with the control group. A. racemosus and glibenclamide treated rats showed decreased lipid peroxidation that is associated with increased activity of superoxide dismutase (SOD) and Catalase (CAT). The ability of A. racemosus on tissue lipid per oxidation and antioxidant status in diabetic animals has not been studied before. The result of this study thus shows that though, A. racemosus possesses moderate antidiabetic activity, but it exhibits potent antioxidant potential in diabetic conditions.

Evaluation of long term shaft resistance of the reused driven pile in clay

  • Cui, Jifei;Rao, Pingping;Wu, Jian;Yang, Zhenkun
    • Geomechanics and Engineering
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    • 제29권2호
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    • pp.171-182
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    • 2022
  • Reusing the used pile has not yet been implemented due to the unpredictability of the bearing capacity evolution. This paper presents an analytic approach to estimate the sides shear setup after the dissipation of pore pressure. Long-term evolution of adjacent soil is simulated by viscoelastic-plastic constitutive model. Then, an innovative concept of quasi-overconsolidation is proposed to estimate the strength changes of surrounding soil. Total stress method (α method) is employed to evaluate the long term bearing capacity. Measured data of test piles in Louisiana and semi-logarithmic time function are cited to validate the effectiveness of the presented method. Comparisons illustrate that the presented approach gives a reasonably prediction of the side shear setup. Both the presented method and experiment show the shaft resistance increase by 30%-50%, and this highlight the potential benefit of piles reutilization.

Predictive factors of substance misuse and abuse in South Korean adolescents: a secondary data analysis of the 2021 Youth Risk Behavior Web-based Survey

  • So Yeon Park
    • Child Health Nursing Research
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    • 제30권1호
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    • pp.67-74
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    • 2024
  • Purpose: This study aimed to identify the general characteristics and health behaviors of students with non-therapeutic substance use. Methods: This secondary data analysis used data from the 17th Korea Youth Risk Behavior Web-based Survey (2021). Analyses of the 54,848 adolescents used descriptive statisics, the Rao-Scott χ2 test, and logistic regression. Results: The risk factors for substance use among students were anxiety, loneliness, living separately from family, suicidal ideation, e-cigarette use, and high stress. Conclusion: The findings help identify the risk factors for non-therapeutic drug use among adolescents. Since South Korea does not have a drug prevention program for its adolescent population, an educational plan based on these findings could help prevent adolescent substance abuse.

대사증후군 노인과 골다공증을 동반한 대사증후군 노인의 건강관련 삶의 질 영향 요인 비교 (Comparison of Health-related Quality of Life Influencing Factors between Metabolic Syndrome and Osteoporotic Metabolic Syndrome in Korean Elderly People)

  • 김은숙
    • 융합정보논문지
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    • 제11권3호
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    • pp.54-67
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    • 2021
  • 본 연구는 국민건강영양조사 제 7기 3차 년도(2018년) 자료를 이용하여 대사증후군 노인과 골다공증을 동반한 대사증후군 노인의 삶의 질에 영향을 미치는 요인을 분석한 2차 자료 연구이다. 연구 대상은 대사증후군 노인 639명, 골다공증을 동반한 대사증후군 노인 161명이 참여하였다. 자료분석은 복합표본 Rao-Scott χ2검정, 일반선형 모형 t-검정 및 회귀모형을 이용하였다. 연구 결과 대사증후군 노인의 삶의 질 저하 요인은 연령, 배우자 동거, 근력운동, 주관적 건강상태, 활동제한, 체질량지수 및 우울이었으며 설명력은 50.4%였다(F=515.96, p<.001). 골다공증을 동반한 대사증후군 노인에서는 연령, 주관적 건강상태, 활동제한 및 스트레스가 삶의 질 저하 요인이었으며 설명력은 48.6%였다(F=10.42, p<.001). 이 결과를 토대로 골다공증 동반 대사증후군 노인에게는 건강상태에 대한 긍정적 수용, 도구적·사회적지지 및 돌봄 지원을 통한 활동제한 문제 해결 및 스트레스 감소 관리를 위한 집중적이고 공격적인 프로그램 개발 및 제공이 필요하다.

화물 중량 분포 변화에 따른 초대형 컨테이너선의 피로 손상에 대한 연구 (A Study on ULCS Fatigue Damage Considering the Variation of Cargo Weight Distribution)

  • 이민아;최신표;박준범
    • 해양환경안전학회지
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    • 제28권4호
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    • pp.667-679
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    • 2022
  • 선박의 피로 손상 해석에는 운항적인 요소를 고려한 매개 변수들을 포함하고 있다. 이러한 운항적인 변수들 때문에 설계 단계에서 예측하는 피로 손상도와 실제 운항 조건을 고려한 피로 손상도간의 차이가 발생한다. 마찬가지로 피로 해석에서 적재 하중 조건을 고려할 때 실제 컨테이너선은 다양한 적재 상태가 존재하지만 설계 단계에서 대표 하중 조건을 선택하여 피로 손상도를 계산한다. 실제 하중 조건과 설계시 하중 조건을 적용하였을 때 피로 손상 계산 결과의 차이가 예상됨에도 불구하고 컨테이너선의 하중 조건에 따른 피로 손상 기여도에 관한 연구는 거의 이루어지지 않은 실정이다. 본 연구에서는 컨테이너선의 화물 중량 분포를 변화시켰을 때 피로 손상기여도를 분석하고자 하였다. 일반적으로 설계 단계에서 적용하는 하중 조건뿐만 아니라 다양한 하중 조건을 생성하고 유체동역학 계산으로 얻을 수 있는 선체 거더 하중 및 스펙트럴 피로 해석을 수행하여 얻은 피로 손상도를 확인하였다. 그 결과, 컨테이너선에서 화물 중량 분포 변화는 선체 거더 하중을 변화시켰으며 선체 거더 응력에 영향을 주어 피로 손상의 변화를 야기시키는 것을 알 수 있었다.

Combining In Silico Mapping and Arraying: an Approach to Identifying Common Candidate Genes for Submergence Tolerance and Resistance to Bacterial Leaf Blight in Rice

  • Kottapalli, Kameswara Rao;Satoh, Kouji;Rakwal, Randeep;Shibato, Junko;Doi, Koji;Nagata, Toshifumi;Kikuchi, Shoshi
    • Molecules and Cells
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    • 제24권3호
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    • pp.394-408
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    • 2007
  • Several genes/QTLs governing resistance/tolerance to abiotic and biotic stresses have been reported and mapped in rice. A QTL for submergence tolerance was found to be co-located with a major QTL for broad-spectrum bacterial leaf blight (bs-blb) resistance on the long arm of chromosome 5 in indica cultivars FR13A and IET8585. Using the Nipponbare (japonica) and 93-11 (indica) genome sequences, we identified, in silico, candidate genes in the chromosomal region [Kottapalli et al. (2006)]. Transcriptional profiling of FR13A and IET8585 using a rice 22K oligo array validated the above findings. Based on in silico analysis and arraying we observed that both cultivars respond to the above stresses through a common signaling system involving protein kinases, adenosine mono phosphate kinase, leucine rich repeat, PDZ/DHR/GLGF, and response regulator receiver protein. The combined approaches suggest that transcription factor EREBP on long arm of chromosome 5 regulates both submergence tolerance and blb resistance. Pyruvate decarboxylase and alcohol dehydrogenase, co-located in the same region, are candidate downstream genes for submergence tolerance at the seedling stage, and t-snare for bs-blb resistance. We also detected up-regulation of novel defense/stress-related genes including those encoding fumaryl aceto acetate (FAA) hydrolase, scramblase, and galactose oxidase, in response to the imposed stresses.

Line${\times}$Tester Analysis of Certain Quantitative Traits in Silkworm Bombyx mori L. under Optimum and Stress Rearing Conditions

  • Rao, P.Sudhakara;Datta, R.K.;Kumari, K.M.Vijaya;Palit, A.K.;Bhat, S.A.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제8권1호
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    • pp.107-112
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    • 2004
  • The combining abilities in the 5 newly evolved thermo tolerant breeds viz., SR6, SR7, SR8 SR9 and SR10 of silkworm Bombyx mori L. and their 15 hybrids were made in a line${\times}$tester crossing programme. Data were analysed for seven quantitative traits i.e., pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, filament length and raw silk percentage under optimum room temperature $(25{\pm}{1^{\circ}C})$ conditions (In case of high temperature $(36{\pm}{1^{\circ}C})$ stress conditions five economic traits except filament length and raw silk percentage) with 3 widely adapted testers i.e., KA, CSR2 and CC1 as lines (females) and testers (males) respectively. The performance at high temperature and low humidity conditions aye only taken into consideration for selecting the best lines/hybrids. Among the lines SR6 exhibited positive General combining ability (GCA) effects for pupation rate, cocoon yield, cocoon weight and cocoon shell ratio traits, followed by SR7 for pupation rate, cocoon yield and cocoon shell weight and cocoon shell ratio. Among testers, KA exhibited positive GCA effects for two quantitative traits cocoon yield, cocoon weight and CSR2 for cocoon shell weight and cocoon shell ratio under adverse temperature conditions. The hybrid SR6${\times}$CC1 and SR7${\times}$CSR2 exhibited significant positive Specific combining ability (SCA) effects for majority of the traits in high temperature stress conditions of rearing. The better parent value of heterosis(Heterobeltiosis) was exhibited by the hybrid SR6${\times}$CC1 for pupation rate, cocoon yield, cocoon weight and cocoon shell weight and SR7${\times}$CSR2 for all the trails evaluated under high temperature conditions. Based on the results, the lines SR6 and SR7 was judged as best combiners and the hybrids SR6${\times}$CC1 and SR7${\times}$CSR2 can be selected for commercial exploitation in tropical climate.

Spectral Fatigue Analysis for Topside Structure of Offshore Floating Vessel

  • Kim, Dae-Ho;Ahn, Jae-Woo;Park, Sung-Gun;Jun, Seock-Hee;Oh, Yeong-Tae
    • Journal of Advanced Research in Ocean Engineering
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    • 제1권4호
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    • pp.239-251
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    • 2015
  • In this study, a spectral fatigue analysis was performed for the topside structure of an offshore floating vessel. The topside structure was idealized using beam elements in the SACS program. The fatigue analysis was carried out considering the wave and wind loads separately. For the wave-induced fatigue damage calculation, motion RAOs calculated from a direct wave load analysis and regular waves with different periods and unit wave heights were utilized. Then, the member end force transfer functions were generated covering all the loading conditions. Stress response transfer functions at each joint were produced using the specified SCFs and member end force transfer functions. fatigue damages were calculated using the obtained stress ranges, S-N curve, wave spectrum, heading probability of each loading condition, and their corresponding occurrences in the wave scatter diagrams. For the wind induced fatigue damage calculation, a dynamic wind spectral fatigue analysis was performed. First, a dynamic natural frequency analysis was performed to generate the structural dynamic characteristics, including the eigenvalues (natural frequencies), eigenvectors (mode shapes), and mass matrix. To adequately represent the dynamic characteristic of the structure, the number of modes was appropriately determined in the lateral direction. Second, a wind spectral fatigue analysis was performed using the mode shapes and mass data obtained from the previous results. In this analysis, the Weibull distribution of the wind speed occurrence, occurrence probability in each direction, damping coefficient, S-N curves, and SCF of each joint were defined and used. In particular, the wind fatigue damages were calculated under the assumption that the stress ranges followed a Rayleigh distribution. The total fatigue damages were calculated from the combination with wind and wave fatigue damages according to the DNV rule.