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.

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%.

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.

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.

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.

A heat shock protein 70 protects the green peach aphid (Myzus persicae) against high-temperature stress

Chen Nan,Tan Jia-Yu,Wang Ying,Qi Ming-Hui,Peng Jiang-Nan,Chen De-Xin,Liu Su,Li Mao-Ye 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.4

Heat shock proteins (HSPs) are encoded by Hsp genes and are important in insect tolerance to heat stress. The green peach aphid, Myzus persicae, is an important agricultural pest. The functions of Hsp genes in the thermal tolerance of M. persicae are unknown. This study identified an Hsp70 gene (MpHsp70a) and analyzed its role in protection against high-temperature stress. MpHsp70a encoded a protein consisting of 659 amino acid residues. The protein had three signature motifs of the HSP70 family and was predicted to be localized in the cytoplasm. The highest expression level of MpHsp70a was in adults, and differences in the mRNA levels between apterous and alate adults were not significant. Exposure to high temperatures (30, 35 and 40 ◦ C) for one hour and treatment with 40 ◦ C for different times (0.5, 1 and 2 h) all resulted in a greatly elevated expression level of MpHsp70a, suggesting that the gene is heat-inducible. The transcriptional level of MpHsp70a was suppressed by injection with double-stranded RNA (dsRNA), and knockdown of MpHsp70a significantly increased the suscep tibility of apterous adults to 40 ◦ C. These results indicate that MpHsp70a is required for tolerance to hightemperature stress in M. persicae. Our findings highlight the molecular mechanism underlying Hsp70-mediated thermal adaptation in M. persicae.

The standard deviations for eigenvalues of the closed-loop systems with random parameters

Chen, Su Huan,Liu, Chun,Chen, Yu Dong Techno-Press 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.3

The vibration control problem of structures with random parameters is discussed, which is approximated by a deterministic one. A method for calculating the standard deviations of eigenvalues of the closed-loop systems is presented by using the random perturbation. The method presented in this paper will not require the distribution function of the random parameters of the systems other than their means and variances. Similarly, the distribution function of the random eigenvalues will not be computed other than their means and variances. The standard deviations of eigenvalues of the uncertain closed-loop systems can be used to estimate the stability robustness. The present method is applied to a vibration control system to illustrate the application. The numerical results show that the present method is effective.

Cardiovascular Medication Use and Risk of Acute Exacerbation in Patients With Asthma-COPD Overlap (CVACO Study)

Su Vincent Yi-Fong,Ko Szu-Wen,Chang Yuh-Lih,Chou Yueh-Ching,Lee Hsin-Chen,Yang Kuang-Yao,Chou Kun-Ta,Hsu Chia-Chen 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.3

Purpose: Current clinical guidelines are unclear regarding the association of cardiovascular medication with the risk of acute exacerbation (AE) in patients with asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). Methods: We conducted a retrospective cohort study by interrogating the claims database of Taipei Veterans General Hospital. Patients with coexistent fixed airflow limitation and asthma were enrolled as an ACO cohort between 2009 and 2017. Exposure to cardiovascular medications, including angiotensin converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), non-selective beta-blockers, cardioselective beta-blockers, dihydropyridine (DHP) calcium channel blockers (CCBs), and non-DHP CCBs, in 3-month period each served as time-dependent covariates. Patients receiving a cardiovascular medication ≥ 28 cumulative daily doses were defined as respective cardiovascular medication users. Patients were followed up until December 31, 2018. The primary endpoint was severe AE, defined as hospitalization or emergency department visit for either asthma, COPD, or respiratory failure. The secondary outcome was moderate AE. Results: The final study cohort consisted of 582 ACO subjects, with a mean follow-up period of 2.98 years. After adjustment, ARB (hazard ratio [HR], 0.64, 95% confidence interval [CI], 0.44–0.93, P = 0.019), cardioselective beta-blocker (HR, 0.29, 95% CI, 0.11–0.72, P = 0.008) and DHP CCB (HR, 0.66, 95% CI, 0.45–0.97, P = 0.035) therapies were associated with lower risks of severe AE. ARB (HR, 0.42, 95% CI, 0.30–0.62, P < 0.001) and DHP CCB (HR, 0.55, 95% CI, 0.38–0.80, P = 0.002) therapies were associated with lower risks of moderate AE. Cardioselective beta-blockers, ARBs, and DHP CCBs were associated with lower risks of severe AE in frequent exacerbators. ACEI, non-selective beta-blocker, or non-DHP CCB use did not change the risk of severe AE. Conclusions: ARB, cardioselective beta-blocker, and DHP CCB therapies may lower the risk of AE in patients with ACO.

Nickel-Tin Solid-Liquid Inter-Diffusion Bonding

Chen-Chiang Yu,배성재,Pei-Chen Su,Tung-Han Chuang 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.1

This paper presents a solid liquid inter-diffusion (SLID) bonding process using nickel-tin. By using two metals with different melting points, Ni3Sn4, an intermetallic compound (IMC) at 523K was formed. Unlike pure metal, the IMC can be used in high temperature applications of up to 800K without failure. The formation energy of Ni3Sn4 IMC was calculated to be 23.15 kJ/mol from the experimental result. Compared to the traditional soldering technique, a higher temperature resistance bonding joint can be achieved using the nickel-tin SLID bonding technique.

Vaccination in patients with inflammatory bowel disease-Asian perspectives: the results of a multinational web-based survey in the 8th Asian Organization for Crohn’s and Colitis meeting

( Su Bum Park ),( Kyeong Ok Kim ),( Hong Sub Lee ),( Chang Hwan Choi ),( Shu Chen Wei ),( Min Hu Chen ),( Katsuyoshi Matsuoka ) 대한장연구학회 2023 Intestinal Research Vol.21 No.3

Background/Aims: Long-term immunosuppressive therapies used to treat inflammatory bowel disease (IBD) are associated with an increased risk of infections, many of which can be prevented by vaccination. We assessed physicians’ current approaches and clinical practices regarding vaccinations for IBD patients in different Asian countries/regions. Methods: An internet-based survey was conducted among members of the Asian Organization for Crohn’s and Colitis from September 2020 to November 2020. The questionnaire consisted of 2 parts covering general opinion on the relevance of vaccinations and clinical practice of vaccination. Results: Overall, 384 Asian medical doctors responded to the survey. The majority of respondents considered it very (57.6%) or sufficiently (39.6%) important to perform vaccinations as recommended by the guidelines. About half of the Asian physicians (52.6%) were usually or always performing vaccinations. The influenza vaccine was the most frequently recommended vaccine for IBD patients. Half of the respondents (51.3%) did not recommend hepatitis A vaccine, especially in China (61.6%) and Japan (93.6%). The diphtheria, tetanus, and pertussis vaccine were never (35.2%) or rarely (29.4%) recommended. Conclusions: The findings of this survey indicated similarities among countries/regions in terms of the current approaches and practices regarding vaccination of IBD patients; however, there are some differences that might reflect each country’s domestic vaccination guidelines and health insurance particularly with certain vaccines in some countries/regions. Although Asian physicians largely recommend vaccination, more awareness among doctors and Asian consensus regarding differences in IBD vaccination among countries/regions may be required. (Intest Res 2023;21:363-374)