Microstructure and Mechanical Properties of Cold Drawn Ti–Nb–Ta–Zr–O Wires for Orthodontic Applications

Wei‑dong Zhang,Junye Ren,Bin Liu,Yong Liu,Zhenggang Wu,Jingwen Qiu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.7

Ti–36Nb–2Ta–3Zr–0.35O (TNTZO) alloy is an excellent candidate for biomedical applications. In this study, a new methodcombining cold-swaging and cold-drawing was used to fabricate the TNTZO alloy wires with 0.3 mm diameter for orthodonticapplications. The microstructure and mechanical properties of cold-drawn and annealed TNTZO wires (referred toas TNTZO0.3and TNTZO0.3(HT), respectively) were investigated. The results show that the microstructure of cold drawnTNTZO0.3consists of main-sized elongated grains with 70 nm width. After annealing at 700 °C for 5 min, the microstructureof TNTZO0.3(HT) wires becomes equiaxial with a grain size of ~ 5 μm. The cold drawn TNTZO0.3wires exhibit improvedmechanical properties, higher tensile strength (about 1000 MPa) and similar elastic modulus (69 GPa), compared to annealedTNTZO0.3(HT) wires. Besides, TNTZO0.3has higher creep resistance and lower stress exponent (around 2), compared to Tiwires and TC4 wires with the same diameter. These results prove that TNTZO0.3wires have most of the ideal characteristicsof orthodontic wires.

Down-regulation of SENP1 Expression Increases Apoptosis of Burkitt Lymphoma Cells

Huang, Bin-Bin,Gao, Qing-Mei,Liang, Wei,Xiu, Bing,Zhang, Wen-Jun,Liang, Ai-Bin Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objective: To investigate the effect of down-regulation of Sentrin/SUMO-specific protease 1 (SENP1) expression on the apoptosis of human Burkitt lymphoma cells (Daudi cells) and potential mechanisms. Methods: Short hairpin RNA (shRNA) targeting SENP1 was designed and synthesized and then cloned into a lentiviral vector. A lentiviral packaging plasmid was used to transfect Daudi cells (sh-SENP1-Daudi group). Daudi cells without transfection (Daudi group) and Daudi cells transfected with blank plasmid (sh-NC-Daudi group) served as control groups. Flow cytometry was performed to screen GFP positive cells and semiquantitative PCR and Western blot assays were employed to detect the inference efficiency. The morphology of cells was observed under a microscope before and after transfection. Fluorescence quantitative PCR and Western blot assays were conducted to measure the mRNA and protein expression of apoptosis related molecules (caspase-3, 8 and 9). After treatment with $COCl_2$ for 24 h, the mRNA and protein expression of hypoxia inducible factor -$1{\alpha}$ (HIF-$1{\alpha}$) was determined. Results: Sequencing showed the expression vectors of shRNA targeting SENP1 to be successfully constructed. Following screening of GFP positive cells by FCM, semiqualitative PCR showed the interference efficiency was $79.2{\pm}0.026%$. At 48 h after transfection, the Daudi cells became shrunken, had irregular edges and presented apoptotic bodies. Western blot assay revealed increase in expression of caspase-3, 8 and 9 with prolongation of transfection (P<0.05). Following hypoxia treatment, mRNA expression of HIF-$1{\alpha}$ remained unchanged in three groups (P>0.05) but the protein expression of HIF-$1{\alpha}$ markedly increased (P<0.05). However, in the sh-SENP1-Daudi group, the protein expression of HIF-$1{\alpha}$ remained unchanged Conclusion: SENP1-shRNA can efficiently inhibit SENP1 expression in Daudi cells. SENP1 inhibition may promote cell apoptosis. These findings suggest that SENP1 may serve as an important target in the gene therapy of Burkitts lymphoma.

Capital, Incomes and Life Styles

Wei-Bin Zhang 서울대학교 경제연구소 1997 Seoul journal of economics Vol.10 No.2

This paper proposes an economic model to analyze an interdependence among capital accumulation. sexual division of labor, and life styles in a perfectly competitive economic system. By life style we mean marital status. We are concerned with the effects of amenity levels of various life styles. Working efficiency and preference on the equilibrium economic structure. We represent a dynamic model and provide the conditions for existence of equilibria. The effects of changes in some parameters on the equilibrium economic structure are examined. It is shown, for instance, that an improvement in the amenity level of women's single life style results in that more men and women live singly.

Growth, Taste Change and the Sexual Division of Labor

Wei-Bin Zhang 서울대학교 경제연구소 1995 Seoul journal of economics Vol.8 No.4

This paper proposes an economic model to analyze a dynamic interaction between economic growth, preference change and sexual division of labor in a perfectly competitive economic system. We show how sexual division of labor between working outside and staying at home are changeable in a sexually just labor market. Conditions for existence of equilibria and stability are provided. Effects of changes in some parameters on the equilibrium economic structure are examined.

Quantitative study on erosion degree of bone china glaze by common acid reagent at different temperature

Wei Hong,Wen-jie Li,Hui-chao Huang,Xiao-wei Weng,Yi-qin Zhang,Xiao-hui Liu,Yan-hua Guo,Ya-bin Su 한양대학교 청정에너지연구소 2022 Journal of Ceramic Processing Research Vol.23 No.6

In this experiment, we selected "Tangshan bone china" 10.5-inch white porcelain flat plate produced by five differententerprises as experimental samples to study the erosion of bone porcelain enamel by different kinds of acidic reagents atdifferent temperatures. The specific experimental process was as follows: at different temperatures, 20% hydrochloric acid,30% sulfuric acid, 100 g/L citric acid and 10% acetic acid were used to continuously erode the sample glaze for 10h, and thewhiteness and 45º mirror direction gloss were measured every 2h. The results show that different acidic reagents at differenttemperatures have significant differences in the erosion characteristics and strength of bone porcelain glaze, and the corrosionresistance of products from different enterprises also have significant differences.

Deflection of Castellated Beams Subjected to Uniformly Distributed Transverse Loading

Wei-bin Yuan,Nan-ting Yu,Zhao-shui Bao,Li-ping Wu 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.3

This paper presents an analytical solution for determining the deflection of castellated/cellular beams with hexagonal/circular web openings, subjected to a uniformly distributed transverse load. The solution is derived using the principle of minimum potential energy. To validate the derived analytical solution, three-dimensional linear finite element analysis is performed using four-node shell elements built-in ANSYS software. Good agreement between the finite element result and the present analytical solution is demonstrated.

Nonlinear Bending of Box Section Beams of Finite Length Under Uniformly Distributed Loading

Wei-bin Yuan,Zhao-shui Bao,Nan-ting Yu,Shuang-shuang Zhu,Li-ping Wu 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.2

In this paper, the bending response of box-section beams of finite length is investigated by using energy methods. The basic assumptions used in the present study are that the total strain energy of a box-section beam subjected to uniformly distributed loading can be simplified into a two-stage analysis process. One is the local bending response of the webs and flanges behaving as plates; the other is the overall bending response of the beam with a deformed cross-section. Analytical solutions for both static and dynamic instabilities of box section beams of finite length subjected to transverse uniformly distributed loading are derived by applying the minimum potential energy principle. To validate the analytical solutions developed, geometric nonlinear finite element analyses are also conducted. Good agreement between the present solutions and the FEA results is demonstrated. Finally, the effects of beam length on the limit critical uniformly distributed load are also discussed.

Growth and Agglomeration of a Small-Open Multi-Regional Economy

( Wei Bin Zhang ) 세종대학교 경제통합연구소 (구 세종대학교 국제경제연구소) 2007 Journal of Economic Integration Vol.22 No.3

We study economic growth of a multi-regional small open economy in a perfectly competitive economy. The national economy consists of multiple regions and each region has one production sector and one housing sector. Following the traditional literature of small open economies, we assume that the rate of interest is fixed in international market. The production side is the same as in the neoclassical growth theory. Households move freely among regions, equalizing utility level among regions by choosing housing, goods and saving. A region`s amenity is endogenous, depending on the region`s output and population. We explicitly solve the dynamics of the multi-regional economy. The system has a unique stable equilibrium point. We simulate the motion of the model and examine effects of changes in the rate of interest, the preference, and amenity parameters. We show, for instance, that a productivity improvement in the region with lowest productivity reduces the GDP and GNP and a rise in the preference for large cities may accelerate agglomeration of the population and economic activities into a region with high productivity.

Buckling Analysis of Steel H Column with Thermal Gradient Along the Flanges

Wei-bin Yuan,Pei-jun Ge,Yue-ting Shen,Shan-shan Cheng,Nan-ting Yu 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.2

This paper presents an analytical study about the axial compression buckling of H-section columns with one side of the flanges exposed to fire. The fire-induced thermal gradient along the flanges is obtained by using simplified Fourier heat conduction equation. The pre-buckling stress and bowing effect due to the non-uniform temperature distribution through the cross-section is considered. The analysis is accomplished by using the Rayleigh–Ritz method. The analytical solution is validated by finite element analysis using ANSYS. Finally, the parametric study is performed for different sections including different values of length, thickness ratio and width-to-height ratio.

SOCIAL STATUS AND INEQUALITY IN AN INTEGRATED WALRASIAN-GENERAL EQUILIBRIUM AND NEOCLASSICAL-GROWTH THEORY

Wei-Bin Zhang 중앙대학교 경제연구소 2017 Journal of Economic Development Vol.42 No.4

This study deals with interactions between social status, economic growth and income and wealth distribution in an economic growth model of heterogeneous households with economic structure. The model emphasizes the role of social status on economic structural change and wealth and income distribution. It is influenced by the ideas related to economic growth and social status in the literature of economic growth and an integrated Walrasian general equilibrium theory and neoclassical growth theory. The economic system consists of one capital goods sector, one consumer goods sector, and any number (of types) of households. The motion is described by a set of differential equations. For illustration, we simulate the motion of the economic system with three groups of households. We identify the existence of a unique stable equilibrium point. We also carry out comparative dynamic analysis. The comparative analyses provide some insights into the complexity of economic growth with social status.