Seismic behavior of T-shaped steel reinforced high strength concrete short-limb shear walls under low cyclic reversed loading

Zongping Chen,Jinjun Xu,Yuliang Chen,Yisheng Su1 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.57 No.4

This paper presents an experimental study of six steel reinforced high strength concrete T-shaped short-limb shear walls configured with T-shaped steel truss under low cyclic reversed loading. Considering different categories of ratios of wall limb height to thickness, shear/span ratios, axial compression ratios and stirrup reinforcement ratios were selected to investigate the seismic behavior (strength, stiffness, energy dissipation capacity, ductility and deformation characteristics) of all the specimens. Two different failure modes were observed during the tests, including the flexural-shear failure for specimens with large shear/span ratio and the shear-diagonal compressive failure for specimens with small shear/span ratio. On the basis of requirement of Chinese seismic code, the deformation performance for all the specimens could not meet the level of ‘three’ fortification goals. Recommendations for improving the structural deformation capacity of T-shaped steel reinforced high strength concrete short-limb shear wall were proposed. Based on the experimental observations, the mechanical analysis models for concrete cracking strength and shear strength were derived using the equivalence principle and superposition theory, respectively. As a result, the proposed method in this paper was verified by the test results, and the experimental results agreed well with the proposed model.

중국 연변지역 布爾哈通河의 수질특성 및 개선방안

임봉수,임상호,윤성일 대전대학교 환경문제연구소 2001 환경문제연구소 논문집 Vol.5 No.-

This study was carried out to suggest the measures and to understand the characteristics of water quality in Buerhatong river within yanbian area, China. Suspended solids appeared high in rainfall season, but BOD and COD appeared lower than suspended solids. The yearly average water quality of all location in this river was less than BOD 2mg/L, less than COD 5mg/L, and ammonia nitrogen was over than 1mg/L in 1997, and was suitable to the class Ⅲ of environmental standard for the surface water. Because of domestic sewage and nightsoil exhausted at Yanji city without treatment system inflowed in this river Synthetical pollution index was calculated for the assessment of water quality, had a tendency to increase near to the downstream. The highest pollution allocation rate is 44% as suspended solids. To reform the deteroriorated river, the sewage wastewater treatment plants will be constructed at Myoungwoal Jin and Yanji city by 2010, respectively. Then COD discharge loading produced in this watershed will be decreased by about 43% of total loading.

고속액체크로마토그래피에 의한 나프록센 광학이성질체의 분리 및 품질관리

정수진,진전성,이은주,이은실,강종성 忠南大學校 生命科學硏究院 醫藥品開發硏究所 2006 藥學論文集 Vol.21 No.-

Enantiomeric separation of naproxen is necessary in drug evaluation processes as the pharmacological activity of naproxen resides mainly in the (S)-enantiomer, The enantioseparation of naproxen was carried out with three different stationary phases. The methods were validated with the terms of linearity, intraday and interday precision, accuracy, selectivity and recovery. Among the selected stationary phases, ChiroSil DMB column with hexane : t-butylmethylether : acetic acid (60:40:0.1, v/v/v) as mobile phase showed the best enantioseparation of the naproxen in the commercial preparations. The wavelength for detection was 270 nm and flow rate was 2.0 mL/min. The contents of (S)-naproxen in the commercial preparations were 92.7 - 98.3%, indicating that all tested preparations were satisfactory to current regulation. However, the contents of (R)-naproxen as impurity in the commercial preparations were varied from 0.08% to 1.08%.

A NOTE ON MATSUSHIMA FORMULA OF DISCRETE UNIFORM SUBGROUPS OF SEMISIMPLE LIE GROUPS

Chen, Su-Shing Department of Mathematics 1971 Kyungpook mathematical journal Vol.11 No.1

Long-Run Performance of Chinese Initial Public Offerings: Further Evidence

Chen Su,Kenbata Bangassa,David Brookfield 한국증권학회 2011 Asia-Pacific Journal of Financial Studies Vol.40 No.2

This study examines the long-run performance of 936 Chinese initial public offerings (IPOs) over the period 1996 to 2005 (the post-issue return evidence ends in June 2008). Using a number of empirical methods, including event-time and calendar-time approaches based on a size and industry matching firm benchmark, we find a significant long-run overperformance using the equal-weighted buy-and-hold abnormal returns, although not for the valueweighted returns, suggesting that the performance of small-size IPO firms is superior to that of large-size IPO firms. The significant overperformance disappears, however, when using cumulative or calendar-time abnormal returns. The preset study provides out-of-sample evidence in an emerging market context in support of Fama’s (1998) argument that reported long-run performance is sensitive to the method of analysis. Finally, based on a rich set of explanatory factors as proxies for both signaling and ex-ante uncertainty characteristics, our results are supportive of the signaling hypothesis, but inconsistent with the divergence of opinion hypothesis.

Robustness analysis of vibration control in structures with uncertain parameters using interval method

Chen, Su Huan,Song, Min,Chen, Yu Dong Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.2

Variations in system parameters due to uncertainties may result in system performance deterioration. Uncertainties in modeling of structures are often considered to ensure that control system is robust with respect to response errors. Hence, the uncertain concept plays an important role in vibration control of the engineering structures. The paper discusses the robustness of the stability of vibration control systems with uncertain parameters. The vibration control problem of an uncertain system is approximated by a deterministic one. The uncertain parameters are described by interval variables. The uncertain state matrix is constructed directly using system physical parameters and avoided to use bounds in Euclidean norm. The feedback gain matrix is determined based on the deterministic systems, and then it is applied to the actual uncertain systems. A method to calculate the upper and lower bounds of eigenvalues of the close-loop system with uncertain parameters is presented. The lower bounds of eigenvalues can be used to estimate the robustness of the stability the controlled system with uncertain parameters. Two numerical examples are given to illustrate the applications of the present approach.

Sofosbuvir/velpatasvir plus ribavirin for Child-Pugh B and Child-Pugh C hepatitis C virus-related cirrhosis

( Chen-hua Liu ),( Chi-yi Chen ),( Wei-wen Su ),( Chun-jen Liu ),( Ching-chu Lo ),( Ke-jhang Huang ),( Jyh-jou Chen ),( Kuo-chih Tseng ),( Chi-yang Chang ),( Cheng-yuan Peng ),( Yu-lueng Shih ),( Chia 대한간학회 2021 Clinical and Molecular Hepatology(대한간학회지) Vol.27 No.4

Background/Aims: Real-world studies assessing the effectiveness and safety of sofosbuvir/velpatasvir (SOF/VEL) plus ribavirin (RBV) for Child-Pugh B/C hepatitis C virus (HCV)-related cirrhosis are limited. Methods: We included 107 patients with Child-Pugh B/C HCV-related cirrhosis receiving SOF/VEL plus RBV for 12 weeks in Taiwan. The sustained virologic response rates at off-treatment week 12 (SVR₁₂) for the evaluable population (EP), modified EP, and per-protocol population (PP) were assessed. The safety profiles were reported. Results: The SVR₁₂ rates in the EP, modified EP and PP were 89.7% (95% confidence interval [CI], 82.5-94.2%), 94.1% (95% CI, 87.8-97.3%), and 100% (95% CI, 96.2-100%). Number of patients who failed to achieve SVR₁₂ were attributed to virologic failures. The SVR₁₂ rates were comparable regardless of patient characteristics. One patient discontinued treatment because of adverse events (AEs). Twenty-four patients had serious AEs and six died, but none were related to SOF/VEL or RBV. Among the 96 patients achieving SVR₁₂, 84.4% and 64.6% had improved Child-Pugh and model for endstage liver disease (MELD) scores. Multivariate analysis revealed that a baseline MELD score ≥15 was associated with an improved MELD score of ≥3 (odds ratio, 4.13; 95% CI, 1.16-14.71; P=0.02). Patients with chronic kidney disease (CKD) stage 1 had more significant estimated glomerular filtration rate declines than patients with CKD stage 2 (-0.42 mL/min/1.73 ㎡/month; P=0.01) or stage 3 (-0.56 mL/min/1.73 ㎡/month; P<0.001). Conclusions: SOF/VEL plus RBV for 12 weeks is efficacious and well-tolerated for Child-Pugh B/C HCV-related cirrhosis. (Clin Mol Hepatol 2021;27:575-588)

Dynamic analysis of Ca^(2+) level during bovine oocytes maturation and early embryonic development

Su Li Liang,Qian Jun Zhao,Xiang Chen Li,Ya Ping Jin,Yi Peng Wang,Xiao Hua Su,Wei Jun Guan,Yue Hui Ma 대한수의학회 2011 Journal of Veterinary Science Vol.12 No.2

Mammalian oocyte maturation and early embryo development processes are Ca^(2+)-dependent. In this study, we used confocal microscopy to investigate the distribution pattern of Ca^(2+) and its dynamic changes in the processes of bovine oocytes maturation, in vitro fertilization (IVF), parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) embryo development. During the germinal vesicle (GV) and GV breakdown stage, Ca^(2+) was distributed in the cortical ooplasm and throughout the oocytes from the MI to MII stage. In IVF embryos, Ca^(2+)was distributed in the cortical ooplasm before the formation of the pronucleus. In 4-8 cell embryos and morulas, Ca^(2+) was present throughout the blastomere. In PA embryos, Ca^(2+) was distributed throughout the blastomere at 48 h, similar to in the 4-cell and 8-cell phase and the morula. At 6 h after activation, there was almost no distribution of Ca^(2+) in the SCNT embryos. However, Ca^(2+) was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos. In this study, Ca^(2+) showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not. Systematic investigation of the Ca^(2+) location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.

Juvenile hormone regulation on the flight capability of Bactrocera dorsalis (Diptera: Tephritidae)

Chen Peng,Chen Min,Ye Hui,Yuan Ruiling,Du Chunhua,Ong Su Ping 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is considered a major economic threat in many regions worldwide. In order to better understand the flight capacity of B. dorsalis and its physiological basis, the functions and regulatory roles of juvenile hormone (JH) in the flight muscle of B. dorsalis were studied under a controlled environment. JH titer of B. dorsalis varied with age and sex. Females have higher JH titers and better flight capabilities than males, given that the increase in JH also corresponded to the ovarian development and maturation in females. The flight duration and distance of both males and females increased with the gradual increase of JH titer after adult emergences. Both JH titer and flight capability peaked in 15-d-old adult and declined subsequently with age. Flight activity stimulated the production of JH as adults flown for 24 h on the flight mills have the highest JH titers compare to adults flown on shorter flight durations. Adults treated with 0.5 µg and 5 µg of JH III were able to fly long durations and long distances, nevertheless when JH titer was too low or too high, it would restrict the flight ability of the fly. The mutual reinforcement of JH and flight activity provides fundamental understanding on the physiological aspects of the flight capability and dispersal, which facilitates strategies for the long-term control of this destructive pest.

A new piezoelectric shell element and its application in static shape control

Chen, Su Huan,Yao, Guo Feng,Lian, Hua Dong Techno-Press 2001 Structural Engineering and Mechanics, An Int'l Jou Vol.12 No.5

In this paper, a new three-dimensional piezoelectric thin shell element containing an integrated distributed piezoelectric sensor and actuator is proposed. The distributed piezoelectric sensor layer monitors the structural shape deformation due to the direct effect and the distributed actuator layer suppresses the deflection via the converse piezoelectric effect. A finite element formulation is presented for static response of laminated shell with piezoelectric sensors/actuators. An eight-node and forty-DOF shell element is built. The performance of the shell elements is improved by reduced integration technique. The static shape control of structure is derived. The shell element is verified by calculating piezoelectric polymeric PVDF bimorph beam. The results agreed with those obtained by theoretical analysis, Tzou and Tseng (1990) and Hwang and Park (1993) fairly well. At last, the static shape control of a paraboloidal antenna is presented.