Experimental Research on Seismic Behavior of +-shaped Columns Reinforced with High-strength Steel Bars under Cyclic Loading

Tie-cheng Wang,Xiao Liu,Hai-long Zhao 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.4

500MPa steel bar is a new type of high-strength reinforcing bar applied in China. To investigate the feasibility of using this type of reinforcement in specially shaped column structure, six +-shaped column specimens varying in axial compression ratio and stirrup spacing were tested under cyclic loading. Behaviors in failure mode, shear crack width, bearing capacity, displacement ductility and energy dissipating capacity are studied to evaluate the seismic resistance performance of the columns. Test results show that 500 MPa steel bars can be effectively used as longitudinal reinforcement and provide more significant confinement to core concrete as transverse reinforcement. It is demonstrated by the observed results that expected oversize flexure-shear crack width can be prevented through an appropriate design procedure following the current building codes in China. Reducing stirrup spacing provides better performance in member ductility, crack behavior, cumulative damage and energy dissipation capacity, but has little influence on the bearing capacity; high axial load can offer advantages in bearing capacity, energy dissipating capacity and shear crack behavior, but reduce the member ductility. To predict the behavior of test specimens under cyclic loading, analytical model are implemented in program OpenSees using flexural fiber beam-column element with the consideration of the shear effect. Analytical results have an acceptable agreement with the test results.

GROUND OBSERVATIONS OF SPRITES AND OTHER TLES IN TAIWAN

WANG YUN-CHING,HSU RUE-RON,SU HAN-TZONG,CHEN ALFRED BING-CHIH,LEE YI-JEN,KUO CHENG-LING,TSAY WEAN-SHUN,CHANG CHAN-KAO,WANG SHI-CHUN,LEE LOU-CHUANG,LIU TIE-YUE The Korean Astronomical Society 2005 Journal of The Korean Astronomical Society Vol.38 No.2

Sprites, elves and blue jets are collectively denominated as the upper atmospheric transient luminous events (TLEs). They are recently discovered optical flashes between active thunderstorms and the ionosphere. In this report, a brief introduction to the most important characteristics of TLEs is given. Since 2001, scientists from the National Cheng Kung University have been performing yearly summer campaigns from various locations in Taiwan. The main achievements of their yearly campaign are presented.

A numerical study on the correlation between the evolution of propeller trailing vortex wake and skew of propellers

Wang, Lian-Zhou,Guo, Chun-Yu,Su, Yu-Min,Wu, Tie-Cheng The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.2

The characteristics of the relationship between the evolution of propeller trailing vortex wake and skew angle are numerically examined based on four different five-blade David Taylor Model Basin (DTMB) model propellers with different skew angles. Numerical simulations are based on Reynolds-averaged Naviere-Stokes (RANS) equations combined with SST $k-{\omega}$ turbulence model. Results show that the contraction of propeller trailing vortex wake can be restrained by increasing skew angle and loading conditions, and root vortices fade away when the propeller skew angle increases. With the increase of the propeller's skew angle, the deformation of the hub vortex and destabilization of the tip vortices are weakening gradually because the blade-to-blade interaction becomes weaker. The transition trailing vortex wake from stability to instability is restrained when the skew increases. Furthermore, analyses of tip vortice trajectories show that the increasing skew can reduce the difference in trailing vortex wake contraction under different loading conditions.

Seismic performance of the thin-walled square CFST columns with lining steel tubes

Xuanding Wang,Jie-Peng Liu,Xian-tie Wang,Guozhong Cheng,Yan Ding 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.3

This paper proposes an innovative thin-walled square concrete filled steel tubular (CFST) column with an octagonal/circular lining steel tube, in which the outer steel tube and the inner liner are fabricated independently of each other and connected by slot-weld or self-tapping screw connections. Twelve thin-walled square CFST columns were tested under quasi-static loading, considering the parameters of liner type, connection type between the square tube and liner, yield strength of steel tube, and the axial load ratio. The seismic performance of the thin-walled square CFST columns is effectively improved by the octagonal and circular liners, and all the liner-stiffened specimens showed an excellent ductile behavior with the ultimate draft ratios being much larger than 1/50 and the ductility coefficients being generally higher than 4.0. The energy dissipation abilities of the specimens with circular liners and self-tapping screw connections were superior to those with octagonal liner and slot-weld connections. Based on the test results, both the finite element (FE) and simplified theoretical models were established, considering the post-buckling strength of the thin-walled square steel tube and the confinement effect of the liners, and the proposed models well predicted the hysteretic behavior of the liner-stiffened specimens.

Isolation and characterization of a protease from the Actinidia arguta fruit for improving meat tenderness

Juan Wang,Haoming Liu,Haili Wang,Mingxun Cui,Qing Jin,Tie Jin,Fushun Cui,Taihua Cui,Cheng Yun Liang,김범식,Guanhao Li 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.4

An protease from Actinidia arguta for improving meat tenderness was purified, characterizedfrom wild A. arguta fruit by ammonium sulfate precipitation, Sephdex G-25 gel filtration chromatography,and DEAE Sepharose Fast Flow ion exchange chromatography, and its activity was investigated. Thepurified protease was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis toobtain a single band of protease. The protease was purified successfully, and found to have a molecularweight of 23.8 kDa (mass spectrometry). The specific activity of the purified protease reached 53,428U/mg with a 25.5-fold purification factor and 9% activity recovery. Based on N-terminal sequencingresults, the A. arguta protease was derived from the class of actinidia proteases that have an Nterminalsequence of VLPDY VDWRS AGAVV. The protease was effective for tenderizing beef anddecomposing actomyosin, suggesting the potential application for improving meat tenderness.

A numerical study on the correlation between the evolution of propeller trailing vortex wake and skew of propellers

Lian-Zhou Wang,Chun-Yu Guo,Yu-Min Su,Tie-Cheng Wu 대한조선학회 2018 International Journal of Naval Architecture and Oc Vol.10 No.2

The characteristics of the relationship between the evolution of propeller trailing vortex wake and skew angle are numerically examined based on four different five-blade David Taylor Model Basin (DTMB) model propellers with different skew angles. Numerical simulations are based on Reynolds-averaged NaviereStokes (RANS) equations combined with SST k u turbulence model. Results show that the contraction of propeller trailing vortex wake can be restrained by increasing skew angle and loading conditions, and root vortices fade away when the propeller skew angle increases. With the increase of the propeller's skew angle, the deformation of the hub vortex and destabilization of the tip vortices are weakening gradually because the blade-to-blade interaction becomes weaker. The transition trailing vortex wake from stability to instability is restrained when the skew increases. Furthermore, analyses of tip vortice trajectories show that the increasing skew can reduce the difference in trailing vortex wake contraction under different loading conditions.

ANALYZING ISUAL SPECTROPHOTOMETER DATA USING A TWO-COLOR DIAGRAM METHOD

CHEN ALFRED BING-CHIH,CHIANG PO-SHIH,HUANG TIAN-HSIANG,KUO CHENG-LING,WANG SHI-CHUN,SU HAN-TZONG,HSU RUE-RoN,CHANG MING-HUI,CHANG YEOU-SHIN,LIU TIE-YUE,MENDE STEPHEN B.,FREY HARALD U.,FUKUNISHI HIROSH The Korean Astronomical Society 2005 Journal of The Korean Astronomical Society Vol.38 No.2

Transient luminous events (TLEs; sprites, elves, jets and etc.) are lightning-related optical flashes occurring above thunderstorms. Since the first discovery of sprites in 1989, scientists have learned a great deal about the morphological, spectroscopic and electromagnetic characteristics of TLEs through ground and spacecraft campaigns. However, most of the TLE studies were based on events recorded over US High Plains. To elucidate the possible biasing effects, space-borne observations are needed and have their merits. Imager of sprites and Upper Atmospheric Lightning (ISUAL) on the FORMOSAT-2 satellite is the first instrument to carry out a true global measurement of TLEs from a low- earth orbit. In this short paper, we apply a common astronomical data analysis technique, two-color diagram, on the ISUAL spectrophotometer (SP) data. By choosing appropriated bandpasses and converting the measured flux of TLEs into the unit of magnitude, two-color diagrams of TLEs can be constructed. We demonstrate that two-color diagrams, which were constructed from the narrow-band spectrophotometer data, can be used to classify different types of TLEs and trace their temporal evolution. The amount of reddening due to Earth's atmosphere can also be estimated from two-color diagrams assembled from the broad-band spectrophotometer data.