The Effects of Electro Slag Welding on Material Properties of Box Column Plates

Cheng-Cheng Chen,Yu-Chen Liang2 한국강구조학회 2011 International Journal of Steel Structures Vol.11 No.2

The effects of electro slag welding (ESW) on the material properties of box column plates, which is ASTM A572 Gr. 50steel, were investigated experimentally and numerically. The material properties of the column plates before and after ESW were evaluated by macro-etching observation, micro-structural observation, and CVN impact tests. The temperature distribution of the column plates, with the ESW heat cycle as the heat input, was simulated by using the ANSYS FEM software. It was found that: (1) The CVN values in the through thickness direction of the base metal can be as low as 14J, 8.1J, and 8.1J at 0oC for plate thicknesses of 32, 40, and 50 mm respectively; (2) During the ESW process, the measured peak temperature for a 25×50 mm column plate surface was as high as 1033, 880 and 744oC for plate thicknesses of 32, 40 and, 50 mm respectively;(3) After the ESW heat cycle, the through thickness CVN value decreased by 68% for the coarse grain heat affected zone (HAZ) of the column pate; (4) The FEM thermal conduction model developed was able to simulate the temperature distribution of the steel plate during the ESW process with reasonable accuracy; (5) To avoid welding penetration due to ESW, a minimum plate thickness is suggested; (6) The impact of ESW heat cycle is more significant for thin column plates compared to thick ones.

Investigation on seismic behavior of combined retaining structure with different rock shapes

Yu-liang Lin,Lianheng Zhao,T.Y. Yang,Guo-lin Yang,Xiao-bin Chen 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.5

A combination of a gravity wall and an anchor beam is widely used to support the high soil deposit on rock mass. In this study, two groups of shaking table test were performed to investigate the responses of such combined retaining structure, where the rock masses were shaped with a flat surface and a curved surface, respectively. Meanwhile, the dynamic numerical analysis was carried out for a comparison or an extensive study. The results were studied and compared between the combined retaining structures with different shaped rock masses with regard to the acceleration response, the earth pressure response, and the axial anchor force. The acceleration response is not significantly influenced by the surface shape of rock mass. The earth pressure response on the combined retaining structure with a flat rock surface is more intensive than the one with a curved rock surface. The anchor force is significantly enlarged by seismic excitation with a main earthquake-induced increment at the first intensive pulse of Wenchuan motion. The value of anchor force in the combined retaining structure with a flat rock surface is generally larger than the one with a curved rock surface. Generally, the combined retaining structure with a curved rock surface presents a better seismic performance.

The National Health Insurance Research Database (NHIRD)

Liang-Yu Lin,Charlotte Warren-Gash,Liam Smeeth,Pau-Chung Chen 한국역학회 2018 Epidemiology and Health Vol.40 No.-

Electronic health records (EHRs) can provide researchers with extraordinary opportunities for population based research. The National Health Insurance system of Taiwan was established in 1995 and covers more than 99.6% of the Taiwanese population; this system’s claims data are released as the National Health Insurance Research Database (NHIRD). All data from primary outpatient departments and inpatient hospital care settings are included in this database. After a change and update in 2016, the NHIRD is maintained and regulated by the Data Science Centre of the Ministry of Health and Welfare of Taiwan. Datasets for approved research are released in three forms: sampling datasets comprising two million subjects, disease-specific datasets, and full population datasets. These datasets are de-identified and contain basic demographic information, disease diagnoses, prescriptions, operations, and investigations. Data can be linked to governmental surveys or other research datasets. While only a small number of validation studies with small sample sizes have been undertaken, they generally report positive predictive values of over 70% across different diagnoses. Currently, patients cannot opt out of inclusion in the database, though this requirement is under review. In conclusion, the NHIRD is a large, powerful data source for biomedical research.

재정적 위기가 중국의 재정 개혁에 미치는 영향

Yu Liang Fu 단국대학교 사회과학연구소 2009 공공정책과 국정관리 Vol.3 No.1

HEREDITARILY HYPERCYCLICITY AND SUPERCYCLICITY OF WEIGHTED SHIFTS

Yu-Xia Liang,Ze-Hua Zhou 대한수학회 2014 대한수학회지 Vol.51 No.2

In this paper we first characterize the hereditarily hyper- cyclicity of the unilateral (or bilateral) weighted shifts on the spaces L² (N,K) (or L²(Z,K)) with weight sequence {An} of positive invert- ible diagonal operators on a separable complex Hilbert space K. Then we give the necessary and sufficient conditions for the supercyclicity of those weighted shifts, which extends some previous results of H. Salas. At last, we give some conditions for the supercyclicity of three different weighted shifts.

Host Range of Cryphonectria parasitica in Korea

Yu-Liang Gao,Byungkwan Kim,Byeongjin Cha 忠北大學校 農業科學硏究所 2016 農業科學硏究 Vol.32 No.2

Cryphonectria parasitica, the pathogen of chestnut blight, was isolated from stem cankers on chestnut trees and it’s host range was investigated on 25 species of various woody plants. Tested trees were inoculated with mycelial plug of C. parasitica through wound on the bark. Among the trees, Quercus aliena, Q. dentata, Q. mongolica, and Q. serrata developed brown discoloration on inner surface of the bark and were determined as new host trees for C. parasitica. Besides the Quercus species, linden tree and white mulberry were infected with the pathogen at less severity and regarded as the reservoir hosts of C. parasitica. When linden tree and white mulberry was inoculated with the isolate bW111, the pathogen could be isolated again, but showed a little difference in colony morphology, vegetative compatibility, and dsRNA size. Re-isolated C. parasitica also showed difference in pathogenicity in the inoculation test and caused the lesions larger than that of bW111 on the stem of chestnut trees. Several new host trees and pathogenicity variation of C. parasitica were reported. It should be taken into account in the analyses of chestnut blight epidemiology and/or developing biological control strategy

Prediction and Monitoring of the Construction Vibration Effect on an Adjacent Old Long Span Double-Convex Arch Bridge

Yu-xiong Liang,Qing-song Feng,Mei-zhen Fu,Bi-tao Wu,Jian-fei Lu,Guo-xi Tang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.5

Ground vibrations caused by the construction of impact drilling piles may affect adjacent bridges, so corresponding prediction and monitoring are necessary to ensure the safety of bridges. In this study, the construction near an existing long-span double-convex arch bridge is taken as a case study to investigate different layouts of construction machines emanating harmful ground vibrations to the existing adjacent bridge by numerical simulations and monitoring. The peak acceleration and velocity acquired from numerical simulations, and monitoring were successfully used to implement impact drilling pile construction near the existing bridge. The results show that there are good consistencies between the monitoring and numerical simulation results, and the vibration acceleration of the foundation of abutments and piers are mainly derived from the vibration caused by the construction within a distance of 50 m, while the construction beyond 50 m has little effect on the old bridge. The numbers and locations of machines near the same foundation may have a weakening or strengthening effect on the peak acceleration and velocity due to destructive and constructive interference of waves, which can help to control the effects of the vibrations of the existing adjacent bridge.

Numerical analysis of large stud shear connector embedded in HFRC

Yu Liang He,Chong Zhang,Li Chao Wang,Ying Yang,Yi Qiang Xiang 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.5

To investigate the mechanical behavior of large stud shear connector embedded in hybrid fiber-reinforced concrete (HFRC), a refined 3D nonlinear finite element (FE) model incorporating the constitutive model of HFRC was developed using ANSYS. Firstly, the test results conducted by the authors (He et al. 2017) were used to validate FE model of push out tests. Secondly, a total of 27 specimens were analyzed with various parameters including fiber volume fractions of HFRC, diameter of studs and HFRC strength. Finally, an empirical equation considering the contribution of steel fiber (SF) and polypropylene fiber (PF) was recommended to estimate the ultimate capacity of large stud shear connector embedded in HFRC.

One-Step Construction of Ni/Co-Doped C–N Nanotube Composites as Excellent Cathode Catalysts for Neutral Zinc–Air Battery

Liang Yu,Qingfeng Yi,Xiaokun Yang,Xiulin Zhou 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

Development of a neutral Zn–air battery is of much significance due to the high stability of zinc in a neutral electrolyte. Here, Ni/Co-doped C–N nanotube composites (C–N, Ni/C–N, Co/C–N, and Ni–Co/C–N) as efficient oxygen reduction reaction (ORR) electrocatalysts in a neutral medium have been prepared by direct pyrolysis of Ni/Co salt, dicyandiamide (DCD) and glucose. Among the synthesized catalysts, Ni–Co/C–N presents a high ORR current density of 8.5mA · cm -2 in a 0.5 mol · L -1 KNO3 solution. The ORR electron transfer number of the catalyst Ni–Co/C–N is 3.8, indicating that O2 is almost completely reduced to H2O. A neutral zinc–air battery utilizing a 0.5 mol · L -1 KNO3 solution has been assembled by using the prepared composite catalyst coated on carbon paper as an air cathode, and Zn plate as an anode. The battery with the cathode catalyst Ni–Co/C–N delivers the open-circuit voltage of 1.13 V and the maximum power density of 65mW · cm -2. The constant discharge current density of 50mA · cm -2, 100 mA · cm -2 and 150mA · cm -2 can last 202 h, 93 h and 11 h, respectively. A stable voltage plateau appears at various discharge current densities. The neutral zinc–air battery can be repeatedly discharged after replacing the zinc anode. Results indicate that the synthesized Ni–Co/C–N catalyst is an excellent cathode material applied to a neutral zinc–air battery, showing broad application prospects as a mobile power source.

An application of quantitative feedback theory in a 3D active vibration isolation platform

Yu-Liang Chung,Meng Shiun Tsai,Jen-Hua Wu 한국소음진동공학회 2003 한국소음진동공학회 국제학술대회논문집 Vol.2003 No.8