Association study between metabolomic profiling and bioactivity of crop diversity

Jiu Liang Xu,Jeong-Sook Shin,Yongsoo Choi 한국분석과학회 2017 학술대회논문집 Vol.2017 No.11

Effect of post weld treatment on cracking behaviors of beam-column connections in steel bridge piers

Liang-Jiu Jia,Hanbin Ge,Toshimitsu Suzuki 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.5

A great number of moment-resisting steel structures collapsed due to ductile crack initiation at welded beam-column connections, followed by explosive brittle fracture in the Kobe (Hyogoken-Nanbu) earthquake in 1995. A series of experimental and numerical studies on cracking behaviors of beam-column connections in steel bridge piers were carried out by the authors’ team. This paper aims to study the effect of post weld treatment on cracking behaviors of the connections during a strong earthquake event. Experiments of three specimens with different weld finishes, i.e., as-welded, R-finish, and burr grinding, were conducted. The experimental results indicate that the instants of ductile crack initiation are greatly delayed for the specimens with R-finish and burr grinding finishes compared with the as-welded one. The strain concentration effect in the connection is also greatly reduced in the specimens with post weld treatment compared with the as-welded one, which was also verified in the tests.

Rotational capacity of H-shaped steel beams under cyclic pure bending

Liang-Jiu Jia,Yafeng Tian,Xianzhong Zhao,Siyuan Tian 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.2

This paper presents experimental study on effects of width-to-thickness ratio and loading history on cyclic rotational capacity of H-shaped steel beams subjected to pure bending. Eight Class 3 and 4 H-shaped beams with large width-to-thickness ratios were tested under four different loading histories. The coupling effect of local buckling and cracking on cyclic rotational capacity of the specimens was investigated. It was found that loss of the load-carrying capacity was mainly induced by local buckling, and ductile cracking was a secondary factor. The width-to-thickness ratio plays a dominant effect on the cyclic rotational capacity, and the loading history also plays an important role. The cyclic rotational capacity can decrease significantly due to premature elasto-plastic local buckling induced by a number of preceding plastic reversals with relative small strain amplitudes. This result is mainly correlated with the decreasing tangent modulus of the structural steel under cyclic plastic loading. In addition, a theoretical approach to evaluate the cyclic rotational capacity of H-shaped beams with different width-to-thickness ratios was also proposed, which compares well with the experimental results.

Ductile cracking simulation procedure for welded joints under monotonic tension

Liang-Jiu Jia,Toyoki Ikai,Lan Kang,Hanbin Ge,Tomoya Kato 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.60 No.1

A large number of welded steel moment-resisting framed (SMRF) structures failed due to brittle fracture induced by ductile fracture at beam-to-column connections during 1994 Northridge earthquake and 1995 Kobe (Hyogoken-Nanbu) earthquake. Extensive research efforts have been devoted to clarifying the mechanism of the observed failures and corresponding countermeasures to ensure more ductile design of welded SMRF structures, while limited research on the failure analysis of the ductile cracking was conducted due to lack of computational capacity and proper theoretical models. As the first step to solve this complicated problem, this paper aims to establish a straightforward procedure to simulate ductile cracking of welded joints under monotonic tension. There are two difficulties in achieving the aim of this study, including measurement of true stress-true strain data and ductile fracture parameters of different subzones in a welded joint, such as weld deposit, heat affected zone and the boundary between the two. Butt joints are employed in this study for their simple configuration. Both experimental and numerical studies on two types of butt joints are conducted. The validity of the proposed procedure is proved by comparison between the experimental and numerical results.

The antioxidant components from one north China mountain herb, Ledum palustre L

XU Jiu Liang,SHANG Ya Fang,PEI Shi Chun,LEE Won Jong,KANG Suk Woo,UM Byung Hun 대한약학회 2012 大韓藥學會 總會 및 學術大會 Vol.2012 No.1

Simultaneous roasting and extraction of green coffee beans by pressurized liquid extraction

Xu, Jiu Liang,Kim, Tae Jin,Kim, Jae-Kwang,Choi, Yongsoo Elsevier 2019 Food chemistry Vol.281 No.-

<P><B>Abstract</B></P> <P>Green coffee extracted by pressurized liquid extraction (PLE) was found to undergo a roasting process similar to traditional roasting. Liquid chromatography-tandem mass spectrometry was used to investigate the chlorogenic acid (CGA) composition and profiling changes by PLE under different extraction conditions and showed almost identical generation and degradation of CGAs occurring during traditional coffee roasting. Compared with the traditional extraction of roasted coffee, optimized PLE coffee showed three- and two-fold higher antioxidant activity and total CGA contents, respectively.</P> <P>Composition diversity and the content of volatile compounds in PLE coffee were found to increase as the PLE temperature increased but were lower than those of traditionally roasted coffee. The sensory attributes of PLE coffee were also evaluated to have be associated with a profile change in the volatile compounds and non-volatile CGA compounds.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Green coffee beans were found to undergo a roasting process by pressurized liquid extraction (PLE). </LI> <LI> Optimized PLE conditions showed almost identical compositions of CGAs occurring during traditional coffee roasting. </LI> <LI> PLE roasting process showed three-fold higher antioxidant activity than traditional extraction of roasted coffee. </LI> <LI> PLE roasting and extraction can be utilized for the development of functional coffee products. </LI> </UL> </P>

Differences in the metabolic profiles and antioxidant activities of wild and cultivated black soybeans evaluated by correlation analysis

Xu, Jiu Liang,Shin, Jeong-Sook,Park, Soo-Kwon,Kang, Sungtaeg,Jeong, Soon-Chun,Moon, Jung-Kyung,Choi, Yongsoo Elsevier Science B.V., Amsterdam. 2017 Vol. No.

<P>Wild soybeans are considered a potential resource for soybean domestication and an important source of genetic diversity for soybean crop improvement. Understanding metabolite-caused bioactivity differences between cultivated and wild soybeans is essential for designing a soybean with enhanced nutritional traits. In this study, the non-targeted metabolic profiling of 26 soybean varieties, 15 wild black soybeans (WBS) and 11 cultivated black soybeans (CBS), using liquid chromatography-mass spectrometry (LC-MS) in combination with multivariate analysis revealed significant differences in 25 differential metabolites. Among these, the soyasaponins Ab and Bb were found to be characteristic metabolites expressed more substantially in CBS than in WBS. Three different antioxidant assays and correlation analysis identified major and minor antioxidants that contributed to WBS having an antioxidant activity 4- to 8-fold stronger than that of CBS. Epicatechin, procyanidin B2, and cyanidin-3-O-glucoside were identified by both association analysis and the online LC-ABTS radical scavenging assay as being major antioxidants.</P>

Study of the Band-gap Structure of a 1D-photonic Crystal by Using Different Numerical Approaches

Liang-Yao Chen,Jian-Bo Chen,Yue-Rui Chen,Yan Shen,Wei-Xi Zhou,Jiu-Chun Ren,Yu-Xiang Zheng 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.4

Comparative studies between the transfer matrices method (TMM) and plane wave method (PWM) approaches have been performed on 1D photonics crystal under different conditions to show the differences between these two kinds of calculations. TMM is suitable for the design of 1D photonic crystal device with high precision and is in good agreement with experimental results, but is not suitable for the 2D and 3D photonic structures which are limited by the complicated boundary conditions at micro interfaces. The result based on the PWM approach to deal approximately with the photonic structure in approximation has not yet been strictly verified by experiment, not even for 1D photonic crystal structures. More efforts will be required to explore its validation under all physical conditions to enhance its application.

Experimental study on seismic performance of partial penetration welded steel beam-column connections with different fillet radii

Hanbin Ge,Liang-Jiu Jia,Lan Kang,Toshimitsu Suzuki 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.6

Full penetration welded steel moment-resisting frame (SMRF) structures with welded box sections are widely employed in steel bridges, where a large number of steel bridges have been in operation for over fifty years in Japan. Welding defects such as incomplete penetration at the beam-column connections of these existing SMRF steel bridge piers were observed during inspection. Previous experiments conducted by the authors' team indicate that gusset stiffeners (termed fillets in this study) at the beam-web-to-column-web joint of the beam-column connections may play an important role on the seismic performance of the connections. This paper aims to experimentally study the effect of the fillet radius on seismic performance of the connections with large welding defects. Four specimens with different sizes of fillet radii were loaded under quasi-static incremental cyclic loading, where different load-displacement relations and cracking behaviors were observed. The experimental results show that, as the size of the fillet radius increases, the seismic performance of the connections can be greatly improved.

Ultra-low cycle fatigue tests of Class 1 H-shaped steel beams under cyclic pure bending

Xianzhong Zhao,Yafeng Tian,Liang-Jiu Jia,Tao Zhang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.4

This paper presents experimental and numerical study on buckling behaviors and hysteretic performance of Class 1 H-shaped steel beam subjected to cyclic pure bending within the scope of ultra-low cycle fatigue (ULCF). A loading device was designed to achieve the pure bending loading condition and 4 H-shaped specimens with a small width-to-thickness ratio were tested under 4 different loading histories. The emphasis of this work is on the impacts induced by local buckling and subsequent ductile fracture. The experimental and numerical results indicate that the specimen failure is mainly induced by elasto-plastic local buckling, and is closely correlated with the plastic straining history. Compared with monotonic loading, the elasto-plastic local buckling can occur at a much smaller displacement amplitude due to a number of preceding plastic reversals with relative small strain amplitudes, which is mainly correlated with decreasing tangent modulus of the material under cyclic straining. Ductile fracture is found to be a secondary factor leading to deterioration of the load-carrying capacity. In addition, a new ULCF life evaluation method is proposed for the specimens using the concept of energy decomposition, where the cumulative plastic energy is classified into two categories as isotropic hardening and kinematic hardening correlated. A linear correlation between the two energies is found and formulated, which compares well with the experimental results.