Steel and FRP double-tube confined RAC columns under compression: Comparative study and stress-strain model

Ming-Xiang Xiong,Guangming Chen,Yue-Ling Long,Hairui Cui,Yaoming Liu 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.43 No.2

Recycled aggregate concrete (RAC) is rarely used in load-carrying structural members. To widen its structural application, the compressive behavior of a promising type of composite column, steel-fiber reinforced polymer (FRP) doubletube confined RAC column, has been experimentally and analytically investigated in this study. The objectives are the different performance of such columns from their counterparts using natural aggregate concrete (NAC) and the different mechanisms of the double-tube and single-tube confined concrete. The single-tube confined concrete refers to that in concrete-filled steel tubular (CFST) columns and concrete-filled FRP tubular (CFFT) columns. The test results showed that the use of recycled coarse aggregates (RCA) affected the axial load-strain response in terms of deformation capacity but such effect could be eliminated with the increasing confinement. The composite effect can be triggered by the double confinement of the steel and carbon FRP (CFRP) tubes but not by the steel and polyethylene terephthalate (PET) FRP tubes. The proposed analysis-oriented stress-strain model is capable to capture the load-deformation history of such steel-FRP double-tube confined concrete columns under axial compression.

Quadrilateral RAC filled FRP tubes: Compressive behavior, design and finite element models

Ming-Xiang Xiong,Xuchi Chen,Fengming Ren 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.48 No.5

The need for carbon neutrality in the world strives the construction industry to reduce the use of construction materials. Aiming to this, recycled aggregate concrete (RAC) could be used as it reduces the carbon dioxide emissions. Currently, RAC is mainly used in non-structural members of civil constructions, seldom used in structural members. To broaden its structural use, a new type of composite column, i.e., the square and rectangular RAC filled FRP tubes (CFFTs), has been concerned in this study. The investigation on their axial compressive behavior through physical test and numerical analysis demonstrated that the load-carrying capacity of such column is reduced with the increase of replacement ratio of recycled aggregate and aspect ratio of section but can be improved by the increase of FRP confining stiffness and corner radius, said capacity can be equivalent to their steel reinforced concrete counterparts. At failure, the hoop strain at corner of tube is unexpectedly smaller than that at flat side of the tube although the FRP tube ruptured at its corner first, revealing a premature failure. Besides, a design-oriented stress-strain model of concrete and an analysis-oriented finite element model are proposed to predict the load-strain response of square and rectangular CFFT columns, which facilitates the engineering use of RAC in loadcarrying structural members.

A high-stability neutron generator for industrial online elemental analysis

Xiang-quan Chen,Lei Xiong,Hui Xie,Jing-fu Guo,Xue-ming Zhang,Yong-jun Dong Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.4

The yield stability of the neutron generator directly affects the accuracy of elemental analysis. This paper presents an industrial fully automatic neutron generator with a 48 mm neutron tube based on PLC to improve the stability and reliability of the neutron generator in industrial applications. By integrating a Kalman Filter with the PID algorithm in a PLC, the neutron yield of the generator is remarkably stabilized, achieving 1 × 10⁸n/s. The neutron generator has been employed for industrial online elemental analysis. The results demonstrate that only a slight fluctuation of ±0.82 % exists in the neutron yield, and the reproducibility of the generator holds at a significant level of 0.05. This improved neutron generator can be applied to the online bulk analysis of carbon in coal-fired power stations and absolute measurement of neutron source emission rate.

Compressive and flexural behaviors of ultra-high strength concrete encased steel members

Yong Du,Ming-Xiang Xiong,Jian Zhu,J.Y. Richard Liew 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.6

One way to achieve sustainable construction is to reduce concrete consumption by use of more sustainable and higher strength concrete. Modern building codes do not cover the use of ultra-high strength concrete (UHSC) in the design of composite structures. Against such background, this paper investigates experimentally the mechanical properties of steel fibre-reinforced UHSC and then the structural behaviors of UHSC encased steel (CES) members under both concentric and eccentric compressions as well as pure bending. The effects of steel-fibre dosage and spacing of stirrups were studied, and the applicability of Eurocode 4 design approach was checked. The test results revealed that the strength of steel stirrups could not be fully utilized to provide confinement to the UHSC. The bond strength between UHSC and steel section was improved by adding the steel fibres into the UHSC. Reducing the spacing of stirrups or increasing the dosage of steel fibres was beneficial to prevent premature spalling of the concrete cover thus mobilize the steel section strength to achieve higher compressive capacity. Closer spacing of stirrups and adding 0.5% steel fibres in UHSC enhanced the post-peak ductility of CES columns. It is concluded that the code-specified reduction factors applied to the concrete strength and moment resistance can account for the loss of load capacity due to the premature spalling of concrete cover and partial yielding of the encased steel section.

SAMD4B, a novel SAM-containing protein, inhibits AP-1-, p53- and p21-mediated transcriptional activity

( Na Luo ),( Guan Li ),( Yong Qing Li ),( Xiong Wei Fan ),( Yue Qun Wang ),( Xiang Li Ye ),( Xiao Yan Mo ),( Jun Mei Zhou ),( Wu Zhou Yuan ),( Ming Tan ),( Hua Ping Xie ),( Karen Ocorr ),( Rolf Bodmer 생화학분자생물학회 (구 한국생화학분자생물학회) 2010 BMB Reports Vol.43 No.5

The sterile alpha motif (SAM) is a putative protein interaction domain involved in a wide variety of biological processes. Here we report the identification and characterization of a novel gene, SAMD4B, which encodes a putative protein of 694 amino acids with a SAM domain. Northern blot and RT-PCR analysis showed that SAMD4B is widely expressed in human embryonic and adult tissues. Transcriptional activity assays show SAMD4B suppresses transcriptional activity of L8G5-luciferase. Over-expression of SAMD4B in mammalian cells inhibited the transcriptional activities of activator protein-1 (AP-1), p53 and p21, and the inhibitory effects can be relieved by siRNA. Deletion analysis indicates that the SAM domain is the main region for transcriptional suppression. The results suggest that SAMD4B is a widely expressed gene involved in AP-1-, p53-and p21-mediated transcriptional signaling activity. [BMB reports 2010; 43(5): 355-361]

Risk Factors for Cervical Cancer in Rural Areas of Wuhan China: a Matched Case-control Study

Zhang, Bin,Zhou, Ai-Fen,Zhu, Chang-Cai,Zhang, Ling,Xiang, Bing,Chen, Zhong,Hu, Rong-Hua,Zhang, Ya-Qi,Qiu, Lin,Zhang, Yi-Ming,Xiong, Chao-Du,Du, Yu-Kai,Shi, Yu-Qin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Cervical cancer is a serious public health problem in developing countries. We investigated possible risk factors for cervical cancer in rural areas of Wuhan China using a matched case-control study with 33 women diagnosed with cervical cancer and 132 healthy women selected from the same area as matched controls. A questionnaire, which included questions about general demography conditions, environmental and genetic factors, the first sexual intercourse, first marriage age, age at first pregnancy, pregnancy first child's age, female personal health history, social psychological factors, dietary habits, smoking and alcohol status and other living habits was presented to all participants. At the same time, HPV infection of every participant was examined in laboratory testing. Results showed HPV infection (P<0.000, OR=23.4) and pregnancy first child's age (P<0.000, OR=13.1) to be risk factors for cervical cancer. Menopause (P=0.003, OR=0.073) was a protective factor against cervical cancer. However, there was no indication of associations of environmental (drinking water, insecticide, disinfectant) genetic (cancer family history), or life-style factors (smoking status, alcohol status, physical training, sleep quality), including dietary habits (intake of fruit and vegetable, meat, fried food, bean products and pickled food) or social psychological factors with cervical cancer. The results suggest that the risk of cervical cancer in Chinese rural women may be associated with HPV infection, menopause and the pregnancy first child's age.

An Analytical–Numerical Hybrid Method for Evaluating Out-of-Plane Stability of Buckling Restrained Braces

Yun Zhou,Chen Gong,Gen-Quan Zhong,Shi-yu Tian,Ming-Xiang Xiong 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.2

Out-of-plane stability of buckling restrained braces (BRBs) has been a critical concern for structural design of them under seismic loads. Although some calculation methods are available in literature catering for the determination of stability resistance of the BRBs, they showed complexities on dealing with numbers of parameters. In this paper, the mechanism of out-of-plane buckling failure of the BRBs was fi rstly introduced; then, an analytically and numerically hybrid method was proposed to calculate the out-of-plane stability resistance of the BRBs with considerations given to solve some key parameters; fi nally, the proposed hybrid method was verifi ed by test results of 4 BRB sub-frames subjected to the lateral loads. The results indicated that the out-of-plane bending deformation of BRB and gusset plate would occur under seismic loads. With an increasing rotation between the end of BRB and the inner core, the out-of-plane buckling failure happened owing to the existence of a plastic hinge at the bottom section of the outstanding part outside the inner core of the BRB. The outof- plane bending stiff ness of BRB and gusset plate, initial imperfection and bending moment capacity of the outstanding part are the key parameters aff ecting the out-of-plane stability of the BRBs. The proposed hybrid method is reasonable and eff ective to calculate the out-of-plane buckling capacity of the BRBs subject to diff erent combinations of axial force and end bending moments.