Creep performance of concrete-filled steel tubular (CFST) columns and applications to a CFST arch bridge

Meng-Gang Yang,C. S. Cai,Yong Chen 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.1

This paper first presents an experimental study of twelve specimens for their creep performance, including nine concrete-filled steel tubular (CFST) columns and three plain concrete columns, subjected to three levels of sustained axial loads for 1710 days. Then, the creep strain curves are predicted from the existing creep models including the ACI 209 model, the MC 78 model, and the MC 90 model, and further a fitted creep model is obtained by experimental data. Finally, the creep effects of a CFST arch bridge are analyzed to compare the accuracy of the existing creep models. The experimental results show that the creep strains in CFST specimens are far less than in the plain concrete specimens and still increase after two years. The ACI 209 model outperforms the MC 78 model and the MC 90 model when predicting the creep behavior of the CFST specimens. Analysis results indicate that the creep effects in the CFST arch bridge are significant. The deflections and stresses calculated by the ACI 209 model are the closest to the fitted model in the three existing models, demonstrating that the ACI 209 model can be used for creep analysis of CFST arch bridges and can meet the engineering accuracy requirement when lack of experimental data.

Zn2þ-Doped Carbon Dots, a Good Biocompatibility Nanomaterial Applied for Bio-Imaging and Inducing Osteoblastic Differentiation In Vitro

Yang Meng,Mingxi Yang,Xinchan Liu,Weixian Yu,Bai Yang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

Multifunctional photoluminescent (PL) nanomaterials have attracted considerable interest in terms of their potential applications in the field of clinical medicine. Carbon dots (CDs), as emerging optical nanomaterials, are promising in various fields including biological imaging, drug transport and nerve tracing. However, little research has investigated on bone tissue engineering as of now. In this study, a new kind of bifunctional Zn2+-doped carbon dots (Zn-CDs) has been synthesized by a one-step hydrothermal method, Zn-CDs show effective fluorescent imaging and induce osteoblastic differentiation abilities in vitro. Moreover, compared with the raw material, Zn-CDs exhibited more effective osteoblastic differentiation promoting capability. Overall, the biocompatible nanomaterial Zn-CDs show potential to be used as a promising novel nanodrug for bone loss therapy and also a monitor of cell variation by fluorescence imaging.

Preparation, Characterization and Properties of Montmorillonite Modified PTFE/Glass Fiber Composites

Yang Meng,Bin Zhang,Juanjuan Su,Jian Han 한국섬유공학회 2020 Fibers and polymers Vol.21 No.5

Inspired by the layered structure and oriented materials, this study exhibits a reinforcement and antibacterialcomposite consisted by polytetrafluoroethylene/glass fiber (PTFE/GF) composites and QACMt. The QACMt used as anorganically modified layered particle is fabricated by a method that montmorillonite (Mt) is modified with quaternaryammonium compounds (QAC). Owing to the composites have a unique layered structure, it was considered as an idealreinforcement to strengthen polymer. Importantly, the tensile strength and toughness of PTFE/GF composites are achievedthe maximal value of 25.5 MPa and 18.1 MJ/m3, respectively. Additionally, the QACMt exhibits good antibacterial activitiesagainst S. aureus and E. coli. This work guides a layered structure to achieve exceptionally high strength and toughness,antibacterial properties.

Preventive Effects of Pyungwi-san against Dextran Sulfate Sodium- and Clostridium difficile-Induced Inflammatory Bowel Disease in Mice

Yang, Meng,Bose, Shambhunath,Lim, Soo-Kyoung,Kim, Hojun MDPI AG 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.24

<P>Several lines of evidence indicate that inflammatory bowel disease (IBD) is associated with Clostridium difficile (CD) infection as a consequence of gut dysbiosis. Currently available treatments of IBD are either not very effective or have adverse effects. Pyungwi-san (PWS), a traditional Chinese herbal formulation, has long been used to treat gastrointestinal disorders. The present study was conducted to investigate the efficacy of PWS against dextran sulfate sodium (DSS) + CD-induced IBD in mice. The animals received DSS in drinking water for seven days to produce DSS-induced acute colitis. In the DSS + CD group, the DSS-fed animals were orally administered with CD spores twice during the DSS treatment period. We observed that exposure of DSS + CD-treated animals to PWS significantly decreased the disease activity index; prevented the shortening of colonic length and increases in spleen size and weight; restored colonic histological parameters by significantly increasing mucus thickness, crypt depth, and goblet cell numbers; protected the tight junction proteins; improved the profiles of pro-inflammatory and anti-inflammatory cytokines; and normalized the abundance ratio of the Firmicutes/Bacteroidetes in the gut. Thus, PWS exerted a number of protective effects on DSS + CD-induced colitis, which might be mediated via restoration of a balance in gut microbial communities.</P>

Field Tests and Finite Element Modeling of a Prestressed Concrete Pipe Pile-Composite Foundation

Meng Yang,Shixia Liu 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.7

The Prestressed Concrete Pipe (PCP) pile-composite foundation was initially employed in the foundation of a culvert in the ancient Yellow River of China. To analyze the reinforcement effect of the foundation, a composite foundation composed of PCP piles was investigated with field tests and numerical simulations. A static load test was conducted to investigate the stress and deformation of the PCP pile-composite foundation, and a finite element model under three-dimensional (3D) axisymmetric conditions was developed to simulate the stress and deformation of the foundation. The Finite Element (FE) model used a nonlinear constitutive model for the soil, cushion and pile-soil interface. The results of the numerical simulations correspond with the load sharing, stress and displacement results of the static load test and indicate that the soil stress is primarily compressive. The cushion reduces the difference in settlement between the middle region and the side region of the bearing plate and increases the bearing capacity of the PCP pile-composite foundation. The stress of the pile significantly varies in the upper 1 m. The pile-soil load-sharing ratio increases with an increase in external load. This paper is expected to be useful for scientific research and efficient applications of PCP pilecomposite foundations.

Insect-induced cecidomyiid galls deficient in light-harvesting protein complex II showing normal grana stacking

Meng-Yuan Huang,Chi-Ming Yang,Man-Miao Yang,Wann-Neng Jane,Yung-Ta Chang 한국응용곤충학회 2009 Journal of Asia-Pacific Entomology Vol.12 No.3

It has been postulated that grana stacking and destacking are mediated by the alteration of the surface charge density on the thylakoid membrane, which is regulated by the LHCII phosphorylation and dephosphorylation cycle. Insect-induced cecidomyiid galls, transformed from Machilus thunbergii Sieb & Zucc. (Lauraceae) leaves, are totally deficient in the pigment–protein complexes CPI and A1 of PSI and AB1 and AB2 of PSII. Although the galls are deficient in LHCII complex, grana stacking is normal. Our data suggest that the LHCII complex may not be the only factor responsible for grana stacking of thylakoid membranes.

SEMA: A Site Equipment Management Assistant for Construction Management

Meng-Han Tsai,Cheng-Hsuan Yang,Chen-Hsuan Wang,I-Tung Yang,Shih-Chung Kang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

Collecting construction equipment information such as the site equipment enter and exit date-time, driver's name, type, and quantity is essential in construction management. Most construction projects use paper to record the equipment access history. However, manual recording is always labour-intensive and time-consuming. Therefore, this research aims to develop an assistant system, Site Equipment Management Assistant (SEMA), to automate the site equipment management processes. With the introduction of image recognition and multiple objects tracking technologies, the proposed system can extract equipment-related information from raw videos. SEMA is designed as a chatbot system that contains three major modules: data acquisition, information extraction, and information delivery. A deep learning-based model was first trained to automatically recognize and track construction equipment passing by the site monitor. Information such as equipment entering and exiting date-time, type, and quantity would be extracted and stored in a database. A chatbot interface was developed for users to obtain data from the database through an intuitive and easy-to-use interface. A system evaluation and usability test were conducted. The results showed that the system could effectively improve the construction equipment management process. SEMA can save 60.7% of users' operation time on obtaining related information.

CNC Corner Milling Parameters Optimization Based on Variable-Fidelity Metamodel and Improved MOPSO Regarding Energy Consumption

Yang Yang,Yuan Wang,Qianfeng Liao,Jiongliang Pan,Junyu Meng,Hao Huang 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.4

In the corner milling process, processing energy consumption is a very important objective, since the energy efficiency of CNC machine is barely above 14.8%. Meanwhile, the excessive processing temperature will increase the thermal deformation of the product and leads to quality decline. Improper process parameters will lead to unnecessary high temperature and energy consumption. By optimizing the process parameters, the appropriate temperature and Specific Energy Consumption can be obtained. This study investigated into modeling Specific Energy Consumption and temperature in corner milling process using variable-fidelity metamodels. The adopted variable-fidelity metamodels are constructed by Hierarchical Kriging, in which 48 sets of low-fidelity data obtained from the AdvantEdge software simulation are used to reflect the trends of the metamodels, and 16 sets of high-precision data obtained from physical experiments are used to calibrate the trends. The experimental cost is reduced and the prediction accuracy is increased by making full use of both sets of data. An improved K-means Multi-objective Particle Swarm Optimization algorithm was adopted and applied on the multi-objective corner milling parameters optimization problem to find satisfactory specific energy consumption and temperature. The obtained Pareto solutions can provide guidance for selecting process parameters according to different requirements, such as reducing energy consumption or temperature.

An approach of evaluation and mechanism study on the high and steep rock slope in water conservancy project

Meng Yang,Huaizhi Su,Zhiping Wen 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.5

In this study, an aging deformation statistical model for a unique high and steep rock slope was proposed, and the aging characteristic of the slope deformation was better reflected. The slope displacement was affected by multiple-environmental factors in multiple scales and displayed the same tendency with a rising water level. The statistical model of the high and steep rock including non-aging factors was set up based on previous analyses and the study of the deformation and residual tendency. The rule and importance of the water level factor as a non-aging unit was analyzed. A partitioned statistical model and mutation model were established for the comprehensive cumulative displacement velocity with the monitoring study under multiple factors and multiple parameters. A spatial model was also developed to reflect and predict the whole and sectional deformation character by combining aging, deformation and space coordinates. A neural network model was built to fit and predict the deformation with a high degree of precision by mastering its feature of complexity and randomness. A three-dimensional finite element model of the slope was applied to approach the structure character using numerical simulations. Further, a three-dimensional finite element model of the slope and dam was developed, and the whole deformation state was analyzed. This study is expected to provide a powerful and systematic method to analyze very high, important and dangerous slopes.

Vitexicarpin Induces Apoptosis in Human Prostate Carcinoma PC-3 Cells through G2/M Phase Arrest

Meng, Fan-Min,Yang, Jing-Bo,Yang, Chun-Hui,Jiang, Yu,Zhou, Yong-Feng,Yu, Bo,Yang, Hong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Vitexicarpin (3', 5-dihydroxy-3, 4', 6, 7-tetramethoxyflavone), a polymethoxyflavone isolated from Viticis Fructus (Vitex rotundifolia Linne fil.), has long been used as an anti-inflammatory herb in traditional Chinese medicine. It has also been reported that vitexicarpin can inhibit the growth of various cancer cells. However, there is no report elucidating its effect on human prostate carcinoma cells. The aim of the present study was to examine the apoptotic induction activity of vitexicarpin on PC-3 cells and molecular mechanisms involved. MTT studies showed that vitexicarpin dose-dependently inhibited growth of PC-3 cells with an $IC_{50}{\sim}28.8{\mu}M$. Hoechst 33258 staining further revealed that vitexicarpin induced apoptotic cell death. The effect of vitexicarpin on PC-3 cells apoptosis was tested using prodium iodide (PI)/Annexin V-FITC double staining and flow cytometry. The results indicated that vitexicarpin induction of apoptotic cell death in PC-3 cells was accompanied by cell cycle arrest in the G2/M phase. Furthermore, our study demonstrated that vitexicarpin induction of PC-3 cell apoptosis was associated with upregulation of the proapoptotic protein Bax, and downregulation of antiapoptotic protein Bcl-2, release of Cytochrome c from mitochondria and decrease in mitochondrial membrane potential. Our findings suggested that vitexicarpin may become a potential leading drug in the therapy of prostate carcinoma.