Experimental Measurement and Numerical Computation of Geogrid Tension in Centrifuge Modeling

Jianfeng Chen,Songbo Yu,Jianfeng Xue,Zhenming Shi 대한토목학회 2011 KSCE JOURNAL OF CIVIL ENGINEERING Vol.15 No.8

Tension measurement of geogrid is essential in reinforcement mechanisms studies. Geogrid is a nonlinear flexible material with large apertures, it is difficult to measure the tensions mobilized in geogrid, especially in scaled-down geogrid in centrifuge modeling. In this study, strain gauges were glued onto the surface of model geogrid with epoxy resin and were calibrated through multi-stage and continuous tensile tests. Generalized Kelvin model was used to fit the constitutive curves from the tensile tests. The model is capable to describe time-dependent and nonlinear behavior of the composite material of epoxy resin and model geogrid. Based on generalized Kelvin model, tensions in the model geogrid were measured in a centrifugal modeling of a reinforced embankment on soft clay. A finite element model was developed to simulate the centrifuge modeling and a comparison was carried out between the computed and measured tensions. The numerical results basically captured the measured reinforcements, indicating that the method of reinforcement measurement proposed in this study is appropriate and reasonable.

Cloning of porcine chemerin, ChemR23 and GPR1 and their involvement in regulation of Lipogenesis

( Jianfeng Huang ),( Jian Zhang ),( Ting Lei ),( Xiaodong Chen ),( Yan Zhang ),( Lulu Zhou ),( An Yu ),( Zhilong Chen ),( Ronghua Zhou ),( Zaiqing Yang ) 생화학분자생물학회 (구 한국생화학분자생물학회) 2010 BMB Reports Vol.43 No.7

Chemerin is a novel adipokine which is abundant in adipose tissue to promote adipocyte differentiation and with significant relativity to BMI and insulin sensitivity. We report here the molecular characterization of porcine chemerin and its receptors ChemR23 and GPR1, as well as their transcriptional regulation during lipogenesis. Chemerin was mainly expressed in liver, intestine, kidney and adipose tissue, consistent with the expression pattern of GPR1, but not ChemR23, which was predominantly present in spleen and temperately in adipose tissue. We further investigated the lipogenesis-related transcriptional activation of PPARγ and KLF15 on chemerin and its receptors. The data showed that KLF15, but not PPARγ, can up-regulate the mRNA level of chemerin, ChemR23 and GPR1, which was consistent with the results of luciferase assay that confirmed the effect of KLF15 on ChemR23 promoter. Taken together, our data provide basic molecular information for the further investigation on the function of chemerin in lipogenesis. [BMB reports 2010; 43(7): 491-498]

WSN Missing Data Imputing Based on Multiple Time Granularity

Jianfeng Xu,Yu Li,Yuanjian Zhang,Azhar Mahmood 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.6

Missing data is a common phenomenon in the data collection process of wireless sensor network (WSN), and the missing data imputing is an important issue of WSN stream data mining. Currently WSN missing data imputing method has little considered about the dynamic characteristics of internal data time structure during the data collection process, which makes data imputing difficult to reflect the real monitoring change objectively. In order to analyze the internal structure and dynamics of WSN time sequence data systematically, with the equivalence relation of the monitored object the time domain can be regarded as a series of integral time granule (ie atomic time point set), a wireless sensor network timing information system (WTIS) is established. The system can reason logically at different time granularity, and a multiple optimal time granularity strategy of WTIS based on hierarchical successive approximation approach is proposed. Finally, based on the research, a multiple optimal time granularity WSN missing data clustering imputing algorithm is proposed. Compared with traditional fixed time granularity missing data imputing algorithm, experiments show that the algorithm can lower error rate when imputing WSN missing data.

Purification and Characterization of β-Agarase from Paenibacillus sp.

Jianfeng Mei,Zhongxiu Tang,Yu Yi,Hong Wang,Qi Wang,Guoqing Ying 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.5

β-Agarase produced by Paenibacillus sp. WL(agarase WL) was purified using a combination of ammoniumsulfate precipitation, DEAE-ion exchange, and gel-filtrationchromatography. The purity of the agarase was increasedby 11.9× with a recovery of 5.1% and a specific activity of4,670.1 U/mg of protein. The molecular mass of thepurified agarase was approximately 30 kDa (SDS-PAGE). The agarase was stable at temperature below 50oC and thefavorable agar-hydrolysis activity was at 40oC. The agarasewas active in the range of pH 5.0 to 8.0, and the optimalagar-hydrolysis pH value was approximately 6.0. Metalions normally found in seawater (Na+, K+, Ca2+, Mg2+, andAl3+) could activate agarase WL. The Michaelis-Mentenconstant Km and maximal reaction velocity Vmax of purifiedagarase WL were 3.22 mg/mL and 41.5 μg/mL·min,respectively. The agarase WL was highly agar specific.

Fusion Detection Algorithm for Infrared Dim Target based on Temporal-Spatial Domain Accumulation and Difference

Jianfeng Wu,Shucai Huang,Hongxia Kang,Yu Zhong 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.11

Aiming at the problem of the dim target real-time detection in Infrared search and track (IRST) systems, a fusion detection algorithm for infrared dim target based on temporal-spatial domain accumulation and difference is proposed. The proposed algorithm suppresses background and enhances targets by template filtering and difference processing in space domain, and the image sequences are processed by multi-frame energy accumulation and frame difference methods according to the target’s moving characteristics in time domain. After the fusion segmentation of the temporal and spatial processing results with definite rule, the target can be detected by the relation of the possible target’s position in adjoining frames according to target’s moving continuity and regularity. Experimental results show that the proposed algorithm enormously increases the target's SNR after the temporal-spatial fusion enhancement, and it has high detection probability and high detecting speed. In the meantime, the algorithm is easy to realize in hardware and can be applied effectively in the real-time target detection of the IRST systems.

Determination of Fluoride Concentration in Antarctic Krill (Euphausia superba) using Dielectric Spectroscopy

Jianfeng Lu,Lina Qi,Wen Guo,Yishan Song,정용안,Yu‐dong Cheng,Yinzhe Jin 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.6

The concentration of fluoride in Antarctic krill (Euphausia superb) was investigated using a coaxial probe method based on dielectric properties in the 0.3–10 GHz frequency range. A quantitative relationship between the fluoride concentration in the aqueous solution and the dielectric loss at 0.3 GHz was also established with a regression coefficient over 0.98. The concentrations of fluoride in fresh and dried krill samples with different krill positions, such as shell and meat, were determined. The detected value agrees well with that determined using other methods, such as fluoride ion-selective electrode (ISE) and potassium permanganate titration (PPT). The fluoride concentrations in fresh krill were 0.0127, 0.0133, and 0.0152 mg/mL using dielectric spectroscopy, PPT, and ISE, respectively. These results show that the proposed dielectric loss technique is suitable and effective for determining fluoride content in Antarctic krill.

Finite element analysis of high-density polyethylene pipe in pipe gallery of nuclear power plants

Shi, Jianfeng,Hu, Anqi,Yu, Fa,Cui, Ying,Yang, Ruobing,Zheng, Jinyang Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.3

High density polyethylene (HDPE) pipe has many advantages over metallic pipe, and has been used in non-safety related application for years in some nuclear power plants (NPPs). Recently, HDPE pipe was introduced into safety related applications. The main difference between safety-related and non-safety-related pipes in NPPs is the design method of extra loadings such as gravity, temperature, and earthquake. In this paper, the mechanical behavior of HDPE pipe under various loads in pipe gallery was studied by finite element analysis (FEA). Stress concentrations were found at the fusion regions on inner surface of mitered elbows of HDPE pipe system. The effects of various factors were analyzed, and the influence of various loads on the damage of HDPE pipe system were evaluated. The results of this paper provide a reference for the design of nuclear safety-related Class 3 HDPE pipe. In addition, as the HDPE pipes analyzed in this paper were suspended in pipe gallery, it can also serve as a supplementary reference for current ASME standard on Class 3 HDPE pipe, which only covers the application for buried pipe application.

Magnetic imprinted nanomicrosphere attached to the surface of bacillus using miniemulsion polymerization for selective recognition of 2,4,6-trichlorophenol from aqueous solutions

Ping Yu,Yongsheng Yan,Qilong Sun,Jianfeng Li,Zhenjiang Tan,Chunxiang Li 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.29 No.-

In the work, we reported an effective method for the preparation of surface molecularly imprintedpolymers based on bacillus as substrate material with superparamagnetic property throughminiemulsion polymerization. Then, the obtained magnetic surface molecularly imprinted polymers(MMIPs) were evaluated as adsorbents for selective recognition 2,4,6-trichlorophenol (2,4,6-TCP) fromaqueous medium. The resulting MMIPs were characterized by several techniques including FT-IR, SEM,TEM, Raman, XRD, VSM and TGA. The results demonstrated rod-shaped MMIPs was covered withimprinted layer, and exhibited chemical stability and good magnetic sensitivity. Batch mode of bindingstudies were carried out to determine the equilibrium isotherm, kinetics, selectivity adsorption andregeneration of MMIPs toward 2,4,6-TCP. The results indicated that the selective adsorption behaviors ofMMIPs were well described by the Langmuir isotherm model and the pseudo-second-order kineticsmodel. The specific adsorption capacity of MMIPs was 45.16 mg g 1 at 298 K, which was 2.15 timeshigher than that of magnetic non-imprinted polymers (MNIPs). The selective recognition studiesdemonstrated the outstanding affinity and selectivity toward 2,4,6-TCP in the presence of competitivephenols. The regeneration study showed excellent adsorption capacity even after five regenerationcycles. In addition, MMIPs were successfully applied to the extraction of 2,4,6-TCP from milk sample.

Preparation and characterization of molecularly-imprinted magnetic microspheres for adsorption of 2,4,6-trichlorophenol from aqueous solutions

Ping Yu,Qilong Sun,Jianfeng Li,Zhenjiang Tan,Jianming Pan,Yongsheng Yan 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.4

Magnetic molecularly imprinted microspheres (MMIS) were successfully prepared by suspension polymerization,and then as-prepared MMIS were used as adsorbents for selective recognition of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solutions. The results composites were characterized by Fourier transform infrared (FT-IR), X-raydiffraction (XRD), thermo gravimetric analysis (TGA), scanning electron microscope (SEM) and vibrating samplemagnetometer (VSM). The results demonstrated that MMIS possesses porous spherical morphology, and exhibits goodthermal stability and magnetic property (Ms=10.14 emu g−1). Then batch mode of binding experiments was used todetermine the equilibrium, kinetics and selectivity recognition. The Langmuir isotherm model fitted the equilibriumdata better than did the Freundlich model, and the maximum adsorption capacity on MMIS was about 1.7 times higherthan that of MNIS. Kinetics behaviors of MMIS were well described by the pseudo-second-order model. MMIS possessedoutstanding selectivity recognition for 2,4,6-TCP in the presence of other competitive phenols (such as sesamol,3-CP, thymol, 2,4-DCP). Furthermore, the reusability performance of MMIS showed about 17.53% loss after five repeatedcycles. Finally, the MMIS were successfully applied to the selective extraction of 2,4,6-TCP from the vegetablesamples.

Seismic Analysis of Reinforced Concrete Bridge Piers Based on Ductile Reinforcement

Linfeng Yu,Shengqiang Ma,Jianfeng Sun,Ahmetjan Kadir 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.12

The reinforced concrete (RC) piers were often damaged at the plastic hinge area by earthquake,therefore, it is necessary to strength the plastic area to resist seismic load. In this study, four RC piers were cast whose dimension was 1/10-scale to the practical one and the main reinforcement ratio was consistent with the practical one. Three of specimens were strengthened by three different materials, such as glass fiber-reinforced polymer (GFRP), aramid fiber-reinforced polymer (AFRP), and hoop stirrup, which were easier to acquire and cost friendly compared with other strengthening methods. These four piers were loaded by a quasi-static test and finite element analysis (FEA) were also conducted. From the experimental results, specimen strengthened by AFRP had best performance, which the lateral resistance, ductility, and energy dissipation of specimens were 16.33%, 34.32%, and 60.58%. GFRP strengthening pier, however, had poor performance in lateral resistance increase of 8.09%, ductility and energy dissipation capacity which the increases were 19.44% and 22%, respectively. The results of FEA are consistent with the experimental results. AFRP had a best performance, which the lateral resistance, ductility, and energy dissipation of specimens were 8.07%, 32.32%, and 45.61%. Compared with the control one, seismic behavior of three strengthened piers had considerable improvement which can be referred to the practical strengthening piers.