Predicting the seismic behavior of torsionally-unbalanced RC building using resistance eccentricity

Ruth A. Abegaz,In-Ho Kim,Han Seon Lee 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.1

The static design approach in the current code implies that the inherent torsional moment represents the state of zero inertial torsional moments at the center of mass (CM). However, both experimental and analytical results prove the existence of a large amount of the inertial torsional moment at the CM. Also, the definition of eccentricity by engineers, which is referred to as the resistance eccentricity, is defined as the distance between the center of mass and the center of resistance, which is conceptually different from the static eccentricity in the current codes, defined as the arm length about the center of rotation. The difference in the definitions of eccentricity should be made clear to avoid confusion about the torsion design. This study proposed prediction equations as a function of resistance eccentricity based on a resistance eccentricity model with advantages of (1) the recognition of the existence of torsional moment at the CM, (2) the avoidance of the confusion by using resistance eccentricity instead of the design eccentricity, and (3) a clear relationship of applied inertial forces at the CM and resisting forces. These predictions are compared with the seismic responses obtained from time-history analyses of a five-story building structure under moderate and severe earthquakes. Then, the trend of the resistance eccentricity corresponding to the maximum edge drift is investigated for elastic and inelastic responses. The comparison given in this study shows that these prediction equations can serve as a useful reference for the prediction in both the elastic and the inelastic ranges.

Magnitude of splash exposure and associated factors among health care workers in Hawassa referral and Adare District hospitals, January 2014

Gudeta Kaweti,Teferi Abegaz 대한직업환경의학회 2017 대한직업환경의학회지 Vol.29 No.-

Background: Accidental splash exposure is one of the common occupational health related problem among health care workers. The problem is worse in developing countries in which the safety practice and protective devices do not properly used. However, little is known on the prevalence and associated factors for splash exposure. Therefore, the main objective of this study was to determine the prevalence of self reported splash exposure and factors that influence those exposures. Methods: Institutional based cross sectional study was done from January 1 to 30, 2014 in Hawassa Referral and Adare District Hospitals. Physicians, nurses, laboratory technicians/ technologists, midwifes, health officers, cleaners, porters and laundry workers were involved in the study. Self administered questionnaires were used for those who can read and understand easily and interview was carried out for those who can’t read and understand. Data was analyzed using SPSS version 16 and logistic regression was carried out to assess the association of selected independent variables with accidental splash exposure. Results: The prevalence of one episode of splash exposure was 28%. There was twofold increased risk of blood and body fluids exposure among health care workers who have multiple responsibilities (AOR = 2.39, 95% CI: 1.27–4.49). Similarly, the risk of exposure was doubled among health care workers who washed linen in the institution (AOR = 2.30, 95% CI: 1.37–3.84) and among those who work in delivery and operation room (AOR = 2.20, 95% CI: 1.10–4.40). Conclusions: Splash exposure is common among health care workers in the study hospitals which warrantee occupational health and safety training.

전단력 및 비틀림 모멘트에 의한 병진 변형 및 비틀림 변형의 상호 작용 효과

김인호,아베가즈 루스 알리,Kim, In-Ho,Abegaz, Ruth A. 한국전산구조공학회 2022 한국전산구조공학회논문집 Vol.35 No.5

국내의 서비스 수준 지진(SLE)과 최대 고려 지진(MCE)의 두 RC 건물 구조물의 실험 및 해석 결과에서 얻은 탄성 및 비탄성 응답은 비틀림에 대한 전단 및 비틀림 거동에서 저항 메커니즘의 특성을 연구하는데 사용될 수 있다. 불균형 구조의 특성 연구에서는 전단력 및 비틀림 모멘트에 대한 병진 변형 및 비틀림 변형의 상호 작용 효과를 나타내는 방정식이 제안하였다. 탄성과 비탄성 거동에서 힘과 변형 사이에 상관 관계 유무가 다르기 때문에 증분 전단력과 증분 비틀림 모멘트를 최대 벽 프레임 변형을 중심으로 항복, 제하 및 재하중 단계로 구분하여 해당 증분 변형 및 증분 비틀림 변형 측면에서 해석을 수행하였다. 두 가지 주요 지배 모드의 탄성 조합에서 병진 변형은 주로 전단력에 기여하는 반면 비틀림 변형은 전체 비틀림 모멘트에 크게 기여한다. 그러나 비탄성 응답에서는 증분 병진 변형이 증분 전단력과 증분 비틀림 모멘트 모두에 기여하게 된다. 따라서 주어진 방정식을 이용하여 비탄성 응답에서 비틀림의 편심 감소, 비틀림 강성 저하 및 겉보기 에너지 생성과 같은 모든 현상들을 설명하였다. The elastic and inelastic responses obtained from the experimental and analytical results of two RC building structures under the service level earthquake (SLE) and maximum considered earthquake (MCE) in Korea were used to weinvestigate the characteristics of the mechanisms resisting shear and torsional behavior in torsionally unbalanced structures. Equations representing the interactive effect of translational drift and torsional deformation on the shear force and torsional moment were proposed. Because there is no correlation in the behavior between elastic and inelastic forces and strains, the incremental shear forces and incremental torsional moments were analyzed in terms of their corresponding incremental drifts and incremental torsional deformations with respect to the yield, unloading, and reloading phases around the maximum edge-frame drift. In the elastic combination of the two dominant modes, the translational drift mainly contributes to the shear force, whereas the torsional deformation contributes significantly to the overall torsional moment. However, this phenomenon is mostly altered in the inelastic response such that the incremental translational drift contributes to both the incremental shear forces and incremental torsional moments. In addition, the given equation is used to account for all phenomena, such as the reduction in torsional eccentricity, degradation of torsional stiffness, and apparent energy generation in an inelastic response.

Adverse effects and non-adherence to antihypertensive medications in University of Gondar Comprehensive Specialized Hospital

Eyob Alemayehu Gebreyohannes,Akshaya Srikanth Bhagavathula,Tamrat Befekadu Abebe,Yonas Getaye Tefera,Tadesse Melaku Abegaz 대한고혈압학회 2019 Clinical Hypertension Vol.25 No.2

Background: A considerable proportion of cardiovascular events could be attributed to poor adherence to antihypertensive medications. Adverse effects can be severe enough to affect adherence to antihypertensive medications. This study aimed to measure the contribution of adverse effects on antihypertensive medications adherence. Methods: The study was conducted from May 1 to June 30, 2017, at the ambulatory clinic of University of Gondar Comprehensive Specialized Hospital (UOGCSH) in Gondar town. A binary logistic regression was performed to determine the significance of the association between adverse effects and adherence to antihypertensive medications. An institution-based cross-sectional study was conducted by administering a questionnaire to hypertensive patients who came for follow-up at the ambulatory clinic of UOGCSH. Level of adherence to antihypertensive medications was used as outcome measure. Results: A total of 249 patients were included in the final analysis with a mean age of 56.51 years and a female majority (53%). The following variables were identified as predictors of poor adherence: tiredness [AOR (95% CI): 3.802 (1.723–8.391), p = 0.001], muscle pain [AOR (95% CI): 5.199 (1.407–19.214), p = 0.013], poor sleep [AOR (95% CI): 4.891 (1.578–15.160), p = 0.006] and, believing that the symptoms were caused by antihypertensive medications [AOR (95% CI): 3.249 (1.248–8.456), p = 0.016]. Conclusion: Adverse effect significantly contributes to antihypertensive medication non-adherence among hypertensive patients