Seismic resistant design of highway bridge with multiple-variable frequency pendulum isolator

Xu Liang,Jianian Wen,Qiang Han,Xiuli Du 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.2

Multiple variable frequency pendulum isolator (MVFPI) has been recently developed as a superior alternative to the traditional friction pendulum bearing (FPB) especially for the seismic isolation in near-fault regions. The MVFPI is characterized by its variable frequency and self-adaptability, which are achieved by piecewise function of sliding surface and shape memory alloy (SMA). The objective of this study is to propose the design algorithm of the MVFPIs in highway bridge as an extension of the direct displacement-based design (DDBD) framework. The nonlinearities of the structural components are taken into account in the design procedure, and the corresponding damage states satisfy the two-stage design philosophy. The accuracy and robustness of the design procedure are verified by an isolated four-span highway bridge through nonlinear time history (NLTH) analyses. The analytical results indicate that the proposed design procedure can predict the profile of deck displacement and amplitude, as well as the damage states of the piers. From statistic aspect, the fragility analyses illustrate that the bridge isolated by MVFPIs exhibits better seismic performance than that of the bridge isolated by FPBs.

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

Experimental investigation and stability analysis on dense-phase pneumatic conveying of coal and biomass at high pressure

Liang Cai,Cai Jiaying,Xu Guiling,Xu Pan,Chen Xiaoping,Zhao Changsui 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.2

Conveying characteristics and flow stability are very important for design and control of a conveying system at high pressure. The influences of operating parameters and material properties on conveying characteristics were investigated in an experimental test facility with a conveying pressure up to 4MPa. Wavelet transform and Shannon entropy analysis were applied to analyzing pressure drops through horizontal pipe in order to obtain the stability criterion. Results indicated that the mass flow rate of biomass decreased, while the mass flow rate of pulverized coal increased at first and then decreased with the increase in fluidization velocity. Solid loading ratios for four kinds of powders decreased with the increase in fluidization velocity. Conveying phase diagrams and pressure drops through different test sections of pulverized coal and biomass at high pressure were obtained and analyzed. The influences of coal category,fracture characteristics and particle size on conveying characteristics were determined.

Dynamic characteristics and experimental study on a wind turbine gearbox

Liang Xu,Caichao Zhu,Hua iju Liu,Guo Chen,Wei Long 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

A gearbox is part of the transmission chain of wind turbine, which can increase rotational speed and reduce torque. Dynamic characteristics of the gearbox directly influence the vibration and the service life of the wind turbine system. In this paper, dynamic behaviors of a megawatt level wind turbine gearbox are studied theoretically and experimentally by dividing the gearbox into a transmission sub-system and a body sub-system. The transmission sub-system, i.e., the gear-shaft-bearing sub-system, is coupled with the gearbox body using bearings which are simulated as mass-less springs. The theoretical study applies a finite element model for the gearbox, where the internal excitations are caused by time-varying stiffness, transmission errors and mesh impacts. The time-varying wind load is considered as the external excitation, collected by a remote real-time online test and transformed into load spectrums through the rain-flow counting method. With boundary conditions and working conditions being defined in the finite element model, the natural characteristic analysis and the dynamic response analysis are conducted. Results show that the operating frequencies of the gearbox are far away from the main natural frequencies of the system, thus avoiding resonances. The main vibration components of the gearbox are with meshing frequencies of the second and third gear stage and their multiplication counterparts. Moreover, the greatest vibration occurs at the bearing housing of the high-speed shaft with the root-mean-square value of its vibration speed less than 3.5 mm/s. A test rig is developed and the experimental vibration conditions are monitored by acceleration sensors. The experimental results are in accordance well with the theoretical results. In this way, the theoretical model is validated. The methodology reported in this paper can provide valuable guidance for practical industrial engineers.

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>

Fabrication and Cell Culturing on Carbon Nanofibers/Nanoparticles Reinforced Membranes for Bone-Tissue Regeneration

Xu Liang Deng,Xiao Ping Yang 한국탄소학회 2012 Carbon Letters Vol.13 No.3

Poly-L-lactic acid (PLLA), PLLA/hydroxyapatite (HA), PLLA/multiwalled carbon nanotubes (MWNTs)/HA, PLLA/trifluoroethanol (TFE), PLLA/gelatin, and carbon nanofibers (CNFs)/β-tricalcium phosphate (β-TCP) composite membranes (scaffolds) were fabricated by electrospinning and their morphologies, and mechanical properties were characterized for use in bone tissue regeneration/guided tissue regeneration. MWNTs and HA nanoparticles were well distributed in the membranes and the degradation characteristics were improved. PLLA/MWNTs/HA membranes enhanced the adhesion and proliferation of periodontal ligament cells (PDLCs) by 30% and inhibited the adhesion of gingival epithelial cells by 30%. Osteoblast-like MG-63 cells on the randomly fiber oriented PLLA/TEF membrane showed irregular forms, while the cells exhibited shuttle-like shapes on the parallel fiber oriented membrane. Classical supersaturated simulated body fluids were modified by CO2 bubbling and applied to promote the biomineralization of the PLLA/gelatin membrane; this resulted in predictions of bone bonding bioactivity of the substrates. The β-TCP membranes exhibit good biocompatibility, have an effect on PDLC growth comparable to that of pure CNF membrane, and can be applied as scaffolds for bone tissue regeneration.

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>

Clinical Implications of p57^KIP2 Expression in Breast Cancer

Xu, Xiao-Yin,Wang, Wen-Qian,Zhang, Lei,Li, Yi-Ming,Tang, Miao,Jiang, Nan,Cai, Shou-Liang,Wei, Liang,Jin, Feng,Chen, Bo Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Objective: To study the relationship between expression of $p57^{KIP2}$ and prognosis and other clinicopathological parameters in invasive breast cancers. Methods: We assessed the expression of $p57^{KIP2}$ in 89 cases of invasive breast cancer and 20 cases of normal breast tissue by immunohistochemical methods and analyzed the results with SPSS software (ver. 16.0). Result: The positive expression rates of $p57^{KIP2}$ protein in the invasive breast cancers and surrounding normal tissue were 30.3% (27/89) and 65% (13/20), respectively. Cases with no $p57^{KIP2}$ expression exhibited a significantly higher post-operative distant metastasis rate than those with $p57^{KIP2}$ expression (37.9% vs. 14.8%; P = 0.01). DFS analysis showed that $p57^{KIP2}$-/C-erbB-2+ tumors also exhibited a significantly higher post-operative distant metastasis rate than the other groups (66.7% vs. 29.2%; P = 0.007), as did $p57^{KIP2}$-/p53+ tumors (64.3% vs. 22.7%; P = 0.001). Survival analysis revealed that $p57^{KIP2}$ was associated with breast cancer-specific survival overall (P = 0.045, log-rank test). Subgroup analysis demonstrated that individuals with $p57^{KIP2}$-/C-erbB-2+tumors experienced significantly worse post-operative survival than those with $p57^{KIP2}$-/C-erbB-2- or other tumors (P = 0.006, log-rank test). $p57^{KIP2}$-/p53+ tumors were associated with significantly worse post-operative survival than $p57^{KIP2}$-/p53- or other tumors (P = 0.001, log-rank test). Cox regression analysis showed that $p57^{KIP2}$ was a non-independent prognostic factor for breast cancer (P = 0.303). Conclusions: $p57^{KIP2}$ is expressed at low levels in invasive breast cancer and is associated with better overall survival rate and disease-free survival in breast cancer patients, but it was a non-independent prognostic factor for breast cancer. Thus, the connection between $p57^{KIP2}$/p53 and $p57^{KIP2}$/C-erbB-2 may provide biomarkers for breast cancer.

Erratum to: Experimental Study and Numerical Analysis on Mechanical Behavior of T-shape Stiffened Orthotropic Steelconcrete Composite Bridge Decks

Xu Jiang,Qing-Tian Su,Xu Han,Changyu Shao,Liang Chen 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.4

Anti-inflammatory, Anti-oxidative and Anti-bacterial Activities of the Constituents Extracted from Leaves of Talipariti hamabo

Xu Hui Liang,김정은,이남호 대한화학회 2023 대한화학회지 Vol.67 No.2

Talipariti hamabo is a plant growing around salt marshes in the Lava Coast region of Jeju Island, Korea. In this study, the extract of T. hamabo leaves was investigated for the anti-inflammatory, anti-oxidative and anti-bacterial activities and their active constituents were identified. In the anti-inflammatory tests using lipopolysaccharide-stimulated RAW264.7 cells, the ethyl acetate (EtOAc) fraction inhibited the nitric oxide production without causing cell toxicity. Moreover, the EtOAc fraction reduced pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-6) as well as prostaglandin E2. In the anti-oxidative studies with DPPH and ABTS+ radicals, potent scavenging activities were observed in the EtOAc and n-butanol fractions. Upon the anti-bacterial tests using Staphylococcus epidermidis, EtOAc and n-butanol fractions exhibited good activities. Through the phytochemical studies on EtOAc fraction, three components were isolated by repeated column chromatography; oleic acid (1), p-hydroxyphenethyl-trans-ferulate (2), nicotiflorine (3). Based on these results, the extract of T. hamabo leaves can be developed as natural resources for cosmetic applications.