Research on Whole‑Process Tensile Behavior of Headed Studs in Steel–Concrete Composite Structures

Liang?Dong Zhuang,Hong?Bing Chen,Yuan Ma,Ran Ding 한국콘크리트학회 2021 International Journal of Concrete Structures and M Vol.15 No.4

The headed studs have been widely applied in steel–concrete composite structures as shear connectors. However, the tensile performance of headed studs is also key to the structural performance in many cases such as the semi-rigid composite joints including steel beam–concrete wall joint and steel column–base joint. Therefore, this study presents experimental and analytical study on the whole-process tensile behavior of headed studs. Tests on a total of 33 pullout specimens are first conducted. The tensile capacity and load–deformation behavior of the anchorage concrete, which dominates the structural performance of headed studs, are thoroughly analyzed. In addition, test data in the literature are collected for quantitatively evaluating the influence of embedment depth, bearing area, boundary conditions, and concrete strength on the tensile behavior of the anchorage concrete. On the basis of the influence evaluation, an analytical model represented by a piecewise function is proposed to describe the whole-process load–deformation behavior of the anchorage concrete and validated through the comparison between the predicted curves and all collected experimental results. Then the proposed model is applied to simulate the rotational behavior of the typical semi-rigid joint anchored by headed studs, which takes the contribution of the anchorage concrete into consideration, and is verified by experimental results. The research findings indicate that tensile behavior of anchorage concrete is crucial to the structural performance of semi-rigid joints, even for headed studs with large embedment depth and bearing area.

단백체를 이용한 애기장대 Cytokinin 유도 단백질의 분석

양영실,차준영,네티 엘마와티,정민희,배동원,이창원,손대영 Plant molecular biology and biotechnology research 2005 Plant molecular biology and biotechnology research Vol.2005 No.

Cytokinins are essential plant hormones that play crucial roles in various aspects of plant growth and development. To better understand the molecular mechanisms of cytokinin action, we identified cytokinin related proteins by a proteomic approach. Proteins extracted from control and trans-zeatin treated Arabidopsis seedlings were separated and analyzed by two dimensional gel analysis. Differentially expressed protein spots were identified with peptide mass fingerprinting based on matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and database searching. We obtained ten up-regulated and one down-regulated proteins upon t-zeatin treatment. The expression of the following proteins was induced; pollen allergen like protein, L-ascorbate peroxidase, tetrapyrrole methylase family protein, SGT1 protein homolog, disease resistance related protein, maternal embryogenesis control protein, paxneb related protein, gluthathione S-transferase and IAA amino acid hydrolase homolog.

퉁퉁마디로부터 색소체 외막 단백질 유전자의 분리 및 발현분석

네티 엘마와티,차준영,양영실,정민희,신동진,이병현,이곤호,손대영 Plant molecular biology and biotechnology research 2004 Plant molecular biology and biotechnology research Vol.2004 No.-

Complementary DNA encoding chloroplast outer envelope membrane protein (OEP) from the halophyte Salicornia herbacea has been cloned and sequenced. The full length cDNA is 596 bp and encodes a polypeptide of 91 amino acid residues with a molecular mass of 8.9 kDa. The expression level of ShOEP increased by salt, drought and ABA treatments. ShOEP expression was largely induced in roots and shoots by high salts. The biological function of ShOEP was examined by yeast complementation. ShOEP can suppress Na+ sensitivity of yeast mutant (cnbΔ) in the presence of salt. These results suggest that ShOEP is a salt inducible gene and may have functions in the regulation of plant salt stress.

Biphasic effects of TGFβ1 on BMP9-induced osteogenic differentiation of mesenchymal stem cells

( Rui Dong Li ),( Zhong Liang Deng ),( Ning Hu ),( Xi Liang ),( Bo Liu ),( Jin Yong Luo ),( Liang Chen ),( Liang Jun Yin ),( Xiao Ji Luo ),( Wei Shui ),( Tong Chuan He ),( Wei Huang ) 생화학분자생물학회(구 한국생화학분자생물학회) 2012 BMB Reports Vol.45 No.9

We have found that the previously uncharacterized bone morphogenetic protein-9 (BMP9) is one of the most osteogenic factors. However, it is unclear if BMP9 cross-talks with TGFβ1 during osteogenic differentiation. Using the recombinant BMP9 adenovirus, we find that low concentration of rhTGFβ1 synergistically induces alkaline phosphatase activity in BMP9-transduced C3H10T1/2 cells and produces more pronounced matrix mineralization. However, higher concentrations of TGFβ1 inhibit BMP9-induced osteogenic activity. Real-time PCR and Western blotting indicate that BMP9 in combination with low dose of TGFβ1 potentiates the expression of later osteogenic markers osteopontin, osteocalcin and collagen type 1 (COL1a2), while higher concentrations of TGFβ1 decrease the expression of osteopontin and osteocalcin but not COL1a2. Cell cycle analysis reveals that TGFβ1 inhibits C3H10T1/2 proliferation in BMP9-induced osteogenesis and restricts the cells in G0/G1 phase. Our findings strongly suggest that TGFβ1 may exert a biphasic effect on BMP9-induced osteogenic differentiation of mesenchymal stem cells. [BMB Reports 2012; 45(9): 509-514]

MicroRNA-27a Inhibits Cell Migration and Invasion of Fibroblast-Like Synoviocytes by Targeting Follistatin-Like Protein 1 in Rheumatoid Arthritis

Dong-liang Shi,Gui-rong Shi,Jing Xie,Xu-zhao Du,Hao Yang 한국분자세포생물학회 2016 Molecules and cells Vol.39 No.8

Fibroblast-like synoviocytes (FLS) with aberrant expres-sion of microRNA (miRNA) are critical pathogenic regula-tors in rheumatoid arthritis (RA). Previous studies have found that overexpression or silencing of miRNA can contribute to the development of miRNA-based therapeutics in arthritis models. In this study, we explored the effects of miR-27a on cell migration and invasion in cultured FLS from RA patients. We found that miR-27a was markedly downregulated in the serum, synovial tissue, and FLS of RA patients. Meanwhile, the expression of follistatin-like protein 1 (FSTL1) was upregulated, which suggests that FSTL1 plays a key role in RA development. The results of a Transwell assay showed that miR-27a inhibited FLS migration and invasion. However, miR-27a inhibition promoted the migration and invasion of FLS. In addition, the down-regulated expression of matrix metalloproteinases (MMP2, MMP9, and MMP13) and Rho family proteins (Rac1, Cdc42, and RhoA) was detected after treatment with miR-27a in RA-FLS by quantitative reverse transcription-PCR and western blot analysis. Then, a luciferase reporter assay validated that miR-27a targeted the 3-untranslated region (3-UTR) of FSTL1. Moreover, miR-27a caused a significant decrease of FSTL1. In addition, the expression of TLR4 and NFκB was inhibited by miR-27a but increased by FSTL1 overexpression. In conclusion, we found that miR-27a inhibited cell migration and invasion of RA-FLS by targeting FSTL1 and restraining the TLR4/NFκB pathway.

Inductor Design Minimizing Power Loss for Boost Converter

Dong Liang,Eun-Sung Seo(서은성),Hwi-Beom Shin(신휘범) 전력전자학회 2016 전력전자학술대회 논문집 Vol.2016 No.7

Morphometrics and paleoecology of <i>Catenipora</i> (Tabulata) from the Xiazhen Formation (Upper Ordovician), Zhuzhai, South China

Liang, Kun,Elias, Robert J.,Choh, Suk-Joo,Lee, Dong-Chan,Lee, Dong-Jin The Paleontological Society 2016 Journal of paleontology Vol.90 No.6

<P>Catenipora is one of the most common tabulate coral genera occurring in various lithofacies in the Upper Ordovician Xiazhen Formation at Zhuzhai in South China. A combination of traditional multivariate analysis and geometric morphometrics is applied to a large number of specimens to distinguish and identify species. Based on three major principal components extracted from 11 morphological characters, three major groups as determined by the cluster-analysis dendrogram are considered to be morphospecies. Their validity and distinctiveness are confirmed by discriminant analysis, descriptive statistics, and bivariate plots. Tabularium area and common wall thickness are the most meaningful characters to distinguish the three morphospecies. Geometric morphometrics is adopted to compare the morphospecies with types and/or figured specimens of species previously reported from the vicinity of Zhuzhai. Despite discrepancies in corallite size, principal component analysis and discriminant analysis, as well as consideration of overall morphological characteristics, indicate that the morphospecies represent C. zhejiangensis Yu in Yu et al., 1963, C. shiyangensis Lin and Chow, 1977, and C. dianbiancunensis Lin and Chow, 1977. Catenipora occurs in seven stratigraphic intervals in the Xiazhen Formation at Zhuzhai, representing a variety of heterogeneous environments. The coralla preservation is variable due to differential compaction; coralla preserved in limestones are commonly intact and in growth position, whereas those in shales are mostly crushed or fragmentary. The size and shape of corallites are considered primarily to be species-specific characters, but are also related to the depositional environments. In all species, morphological characters, including corallite size, septal development, and shape and size of lacunae, show high variability in accordance with lithofacies and stratigraphic position. The intraspecific differences in corallite size at various localities in the Zhuzhai area may indicate responses to local environmental factors, but may also reflect genetic differences if there was limited connection among populations.</P>

Adaptive Synchronization of Leader-Follower Networked Systems against Communication Attenuation and Actuators Faults

Liang Dong,Jian-Hui Wang,Shu-Sheng Gu,Yuan-Bo Shi,Fang-Mei Zhao 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.6

This paper addresses the adaptive asymptotic synchronization problem of a class of leader-follower largescale networked systems against communicated signal attenuation and actuator bias faults. Adaptive mechanismsare constructed to estimate each unknown faulty factor of communications and actuators on-line. Based on theestimations, an adaptive compensation controller is designed to automatically remove the unexpected impacts ofcommunication and actuator faults. Through the adaptive adjustment parameters and Lyapunov functions, theachievement of asymptotic synchronization of the leader-follower large-scale networked system with the improperactuator and faulty transmitted signals is obtained. Finally, the synchronization results are validated by a multiplevehicle large-scale device.

Mathematical model and meshing analysis of internal meshing gear transmission with curve element

Dong Liang,Weibin Li,Bingkui Chen 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.12

A new internal meshing gear transmission with curve element is put forward in this paper. The mathematical principle of tooth profile generation is described based on conjugate curves theory. For a given spatial curve, the meshing equation and its conjugated spatial curve under the motion law were derived. Considering the equidistant kinematic method, general internal tooth profiles models were established by the conjugate-curve pair. Numerical example of the internal gear pair was developed according to gear parameters and gear solid models were established by MATLAB and UG software. Motion simulation result shows that the gear pair satisfies point contact condition and design requirements. Meshing analysis of tooth profiles using FEA method was carried out. Stress analysis results of tooth profiles with single point contact and two points contact were, respectively, obtained. The conclusions lay the foundation for multi-point contact generation and tooth profile design. Also, further studies on transmission characteristics and manufacturing technology of the new gear drive will be carried out.

Quantitative Stability Analysis of an Unmanned Tethered Quadrotor

Dong Liang,Li Ding,Mingyue Lu,Rui Ma,Jie Cao 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.3

Tethered quadrotors, unmanned aerial quadrotors connected to a fixed point via tether cables, have been widely applied in numerous aerial tasks. However, their structural parameters and external disturbances give rise to dynamic stability issues, resulting in uncontrolled autonomous flight, shaking, and vibrating. Thus, this article investigates the quantitative stability of a tethered quadrotor using the Lyapunov exponent approach. First, a mathematical model of the tethered quadrotor is developed, and its dynamic stability is quantified to verify the rationality of the designed physical prototype and enhance the aerial system’s stability. Both simulation and experimental results show that the dynamic stability during the landing phase is better than that during takeoff. Finally, optimizing the structural parameters enhances the dynamic stability, which is sensitive to cable length, wind gusts, and yaw angle.