Numerical Investigation and Design of Cold-formed Steel Angle Columns with Complex Edges under Axial Compression

Jun-Feng Zhang,Mengmeng Feng,En-Feng Deng,Shiyun Pang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.2

Currently, cold-formed steel (CFS) is widely used in fabricated steel structures for high strength-to-weight ratio and ease for installation. However, limited research is available in the literature on the CFS angle columns with complex edges under axial compression. In this paper, the axial compressive capacity of the CFS angle columns with complex edges was numerically studied. The distortional buckling characteristics of 1008 CFS angle sections with complex edges were analyzed by finite strip software CUFSM. Detailed non-linear finite element model (FEM) was developed based on finite element program ABAQUS and verified by comparing with test results. The verification indicated that the developed FEM could well predict the ultimate strength and failure model of the specimens. Using the validated FEM, an extensive parametric study comprised of 330 models was conducted. The influences of the specimen length, the edge ratio and the limb-width ratio of the angle section on the axial compressive capacity of CFS angle columns with complex edges were evaluated. Then an improved direct strength method (DSM) was proposed based on the existing DSM. The evaluations based on tests and FEA results showed that using the modified DSM to predict the load-bearing capacity of the CFS angle columns with complex edges was feasible.

Macrophages Promote Coal Tar Pitch Extract-induced Tumorigenesis of BEAS-2B Cells and Tumor Metastasis in Nude Mice Mediated by AP-1

Zhang, Peng,Jin, Yue-Fei,Zhang, Qiao,Wu, Yi-Ming,Wu, Wei-Dong,Yao, Wu,Wu, Yong-Jun,Li, Zhi-Tao,Zhao, Yong,Liu, Yu,Feng, Fei-Fei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background: We sought to evaluate the role of tumor associated macrophages (TAMs) on the promotion of coal tar pitch extract (CTPE)-induced tumorigenesis of human bronchial epithelial cells (BEAS-2B) and tumor metastasis in nude mice, and related mechanisms. Materials and Methods: BEAS-2B cells were first treated with 2.4 mg/mL CTPE for 72 hours. After removal of CTPE, the cells were continuously cultured and passaged using trypsin-EDTA. THP-1 cells were used as macrophage-like cells. BEAS-2B cells under different conditions (n=6/group) were injected into the back necks of nude mice, and alterations of tumor xenograft growth, indicative of tumorigenicity, and tumor metastasis were determined. Pathological changes (tumor nests and microvascular lesions) of HE-stained tumor tissues were also evaluated. The expression of AP-1(c-Jun) in xenografts and metastatic tumors was determined using immunohistochemistry. Results: Tumor size and weight in nude mice transplanted with the mixture of CTPE-induced passage 30 BEAS-2B and THP-1 cells (2:1) were increased compared to those from the CTPE-treated BEAS-2B cells at passage 30 alone at different observation time points. Tumor metastasis to lymph nodes and liver was only detected after transplantation of a mixture the two kinds of cells. The numbers of tumor nests and microvascular lesions, and the expression levels of AP-1 (c-Jun) in tumors from the mixture of two kinds of cells were increased apparently in contrast to those in tumor from the CTPE-treated BEAS-2B cells of passage 30 alone. In addition, there was positive correlation between AP-1 (c-Jun) expression level and the number of microvascular lesions, or between AP-1 (c-Jun) expression level and tumor metastasis in these two groups. Conclusions: TAMs not only facilitate tumorigenesis transformation of CTPE-induced BEAS-2B cells, but also promote tumor growth, angiogenesis and metastasis in nude mice in vivo, which may be mediated by AP-1.

Growth and fixed points of meromorphic solutions of higher-order linear differential equations

Jun-Feng Xu,Hong-Xun Yi 대한수학회 2009 대한수학회지 Vol.46 No.4

In this paper, we investigate the growth and fixed points of meromorphic solutions of higher order linear differential equations with meromorphic coefficients and their derivatives. Because of the restriction of differential equations, we obtain that the properties of fixed points of meromorphic solutions of higher order linear differential equations with meromorphic coefficients and their derivatives are more interesting than that of general transcendental meromorphic functions. Our results extend the previous results due to M. Frei, M. Ozawa, G. Gundersen, and J. K. Langley and Z. Chen and K. Shon. In this paper, we investigate the growth and fixed points of meromorphic solutions of higher order linear differential equations with meromorphic coefficients and their derivatives. Because of the restriction of differential equations, we obtain that the properties of fixed points of meromorphic solutions of higher order linear differential equations with meromorphic coefficients and their derivatives are more interesting than that of general transcendental meromorphic functions. Our results extend the previous results due to M. Frei, M. Ozawa, G. Gundersen, and J. K. Langley and Z. Chen and K. Shon.

Characterization of CNT/TiO₂ Electrode Prepared Through Impregnation with TNB and Their Photoelectrocatalytic Properties

Feng Jun Zhang,Ming Liang Chen,Won Chun Oh 대한환경공학회 2009 Environmental Engineering Research Vol.14 No.1

In this study, we have prepared three kinds of carbon nanometer tube (CNT)/TiO₂ electrodes through impregnation with different concentration titanium n-butoxide (TNB) solution. The prepared electrodes were characterized with surface properties, structural crystallinity, elemental identification and photoelectrocatalytic activity. The N2 adsorption data showed that the composites had decreased surface area compared with the pristine CNT. This indicated the blocking of micropores on the surface of CNT, which was further supported by observation via SEM. XRD results showed patterns for the composites and a typical single and clear anatase crystal structure. The main elements such as C, O and Ti were existed for all samples from the EDX data. The catalytic efficiency of the developed electrode was evaluated by the photoelectrodegradation of methylene blue (MB). The positive potential applied in photoelectrocatalytic (PEC) oxidation was studied. It was found that photoelectrocatalytic (PEC) decomposition of MB solution could be attributed to combination effects between TiO₂ photocatalytic and CNT electro-assisted. Through the comparison between photocatalytic (PC) oxidation and photoelectrocatalytic (PEC) oxidation, it was found that the PEC oxidation efficiency for MB is higher than that of PC oxidation.

Calcium precipitation to remove fluorine in groundwater: Induced by Acinetobacter sp. H12 as a template

Jun Feng Su,Ruijie Zhang,Xiaofen Hu,Amjad Ali,Zhao Wang 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.3

Calcium precipitation induced by Acinetobacter sp. H12 can simultaneously remove F− and Ca2+. Adsorption kinetics and isotherm studies showed that the defluoridation effect improved with the increase of temperature and time. The equilibrium adsorption capacity of calcium precipitation was 7.43 mg g−1 at the initial F− concentration of 10 mg L−1. Moreover, as the pH increased, the F− adsorption capacity decreased and the Ca2+ removal rate gradually increased. The adsorption process was highly fitted to the pseudo-second-order and the Freundlich isotherm. Adsorption thermodynamics analysis demonstrated that the adsorption process was a spontaneous endothermic reaction. The activation adsorption energy was 2.81 kJ mol−1 and the frequency coefficient was 10.88 h−1. EEM, SEM, XPS. XRD results indicated that the defluoridation mechanism may be due to adsorption and co-precipitation. The mechanism of Ca2+ removal may be co-precipitation with F−. It is worth-mentioning that calcium precipitation overcame the problem of adding carbon sources and avoided the microbial safety risk in the effluent. Therefore, a new insight was proposed for simultaneous remediation of Ca2+ and F− from groundwater combining the biological and chemical method.

The Action Research of Game Sense on Elementary School Soccer Team Training

Jun-Feng Zhong,Yuh-Chih Chen 한국스포츠교육학회 2011 한국스포츠교육학회 국제학술대회 자료집 Vol.2011 No.12

Electro-chemical Preparation of TiO₂/CNT Electrodes with TNB Electrolyte and Their Photoelectrocatalytic Effect

Feng-Jun Zhang,Ming-Liang Chen,Won-Chun Oh 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.6

We investigate a method for the electrochemical preparation of titanium dioxide/carbon nanotube (TiO₂/CNT) composites involving the electroplating of Ti in a titanium n-butoxide (TNB) electrolyte into a CNT matrix. The Brunauer-Emmett-Teller (BET) surface areas of TiO₂/CNT composites decrease as the electrochemical operating time increases. Changes in XRD patterns show a typical anatase type on the TiO₂/CNT composite prepared with a CNT matrix by the electroplating method in a TNB solution. In SEM micrographs, the titanium complex particles are uniformly distributed on the CNT surface. The results of chemical elemental analysis for the TiO₂/CNT composites show that most of the spectra for these samples produce stronger peaks for carbon and Ti metal than for any other element. Finally, the prominent photoelectrocatalytic activities of the TiO₂/CNT composites can be attributed to the combined effects of photodegradation of TiO₂, electron assistance of CNT, and the application of a sufficient voltage.

A novel M2e-multiple antigenic peptide providing heterologous protection in mice

Feng Wen,Ji-Hong Ma,Hai Yu,Fu-Ru Yang,Meng Huang,Yan-Jun Zhou,Ze-Jun Li,Xiu-Hui Wang,Guo-Xin Li,Yi-Feng Jiang,Wu Tong,Guangzhi Tong 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.1

Swine influenza viruses (SwIVs) cause considerable morbidity and mortality in domestic pigs, resulting in a significant economic burden. Moreover, pigs have been considered to be a possible mixing vessel in which novel strains loom. Here, we developed and evaluated a novel M2e-multiple antigenic peptide (M2e-MAP) as a supplemental antigen for inactivated H3N2 vaccine to provide cross-protection against two main subtypes of SwIVs, H1N1 and H3N2. The novel tetra-branched MAP was constructed by fusing four copies of M2e to one copy of foreign T helper cell epitopes. A high-yield reassortant H3N2 virus was generated by plasmid based reverse genetics. The efficacy of the novel H3N2 inactivated vaccines with or without M2e-MAP supplementation was evaluated in a mouse model. M2e-MAP conjugated vaccine induced strong antibody responses in mice. Complete protection against the heterologous swine H1N1 virus was observed in mice vaccinated with M2e-MAP combined vaccine. Moreover, this novel peptide confers protection against lethal challenge of A/Puerto Rico/8/34 (H1N1). Taken together, our results suggest the combined immunization of reassortant inactivated H3N2 vaccine and the novel M2e-MAP provided cross-protection against swine and human viruses and may serve as a promising approach for influenza vaccine development.

Expression patterns of octoploid strawberry TGA genes reveal a potential role in response to Podosphaera aphanis infection

Jun Feng,Yang Cheng,Caixia Zheng 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.1

TGA family transcription factors are downstream components of the salicylic acid (SA) pathway and play a crucial role in the penetration defense against powdery mildew, a disease caused by the biotrophic pathogen Podosphaera aphanis that can cause enormous financial losses. However, the TGA genes in the octoploid strawberry (Benihoppe) remain largely unexplored. In this study, 11 FaTGA genes were identified and grouped into five subgroups based on the Strawberry GARDEN database. The evolution of TGAs has been relatively conservative, maintaining nearly the same protein domain and motif architectures. RT-qPCR showed that FaTGA s have different expression patterns in roots, stems, and leaves. The characteristics of their gene expression patterns indicate that FaTGA1, FaTGA2, FaTGA5, FaTGA7, FaTGA8, FaTGA9, and FaTGA10, as well as SA-responsive genes, were responsive to P. aphanis infection. In particular, exogenous SA induced significant upregulation of FaTGA and SA-responsive genes. Further correlation analysis suggested that FaTGA1, FaTGA2, FaTGA5, FaTGA7, FaTGA8, and FaTGA10 may play a crucial role in the response to powdery mildew disease. Taken together, our results reveal the responses of TGA genes in the strawberry P. aphanis interaction, which will provide further insight into the strawberry defense against powdery mildew.

Dynamic Analysis of Spine Sagittal Balance during Walking Using Motion Analysis Technology

Jun Feng,Yoon Hyuk Kim,Kyungsoo Kim 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12