Free vibration analysis of circular cylindrical shell on elastic foundation using the Rayleigh-Ritz method

Jinsong Yang,Jianbin Cao,Jingsong Xie,Haixiao Zhao 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.1

A general approach is presented for the free vibration analysis of circular cylindrical shell resting on elastic foundation and subjected to classical boundary conditions of any type. The Winkler/Pasternak model is utilized to simulate the elastic foundation imposed on the cylindrical shell, and then it is easily to derive the potential energy of the elastic foundation. Based on the Flügge shell theory, explicit expressions for the mass and stiffness matrices are obtained. By taking the characteristic beam modal functions as the admissible functions, the Rayleigh-Ritz method is employed to derive the frequency equations of circular cylindrical shell with all the classical boundary conditions and resting on elastic foundation. Once the frequency equation has been determined, the frequencies can be calculated numerically. The excellent accuracy and validity of the present approach are demonstrated by numerical examples and comparisons with the results available in the literature. Finally, some further numerical results are given to illustrate the comprehensive effect of geometric properties and foundation coefficients on the frequencies of circular cylindrical shell in contact with elastic foundation.

A hybrid-separate strategy for force identification of the nonlinear structure under impact excitation

Jinsong Yang,Jie Liu,Jingsong Xie 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.85 No.1

Impact event is the key factor influencing the operational state of the mechanical equipment. Additionally, nonlinear factors existing in the complex mechanical equipment which are currently attracting more and more attention. Therefore, this paper proposes a novel hybrid-separate identification strategy to solve the force identification problem of the nonlinear structure under impact excitation. The ‘hybrid’ means that the identification strategy contains both l1-norm (sparse) and l2-norm regularization methods. The ‘separate’ means that the nonlinear response part only generated by nonlinear force needs to be separated from measured response. First, the state-of-the-art two-step iterative shrinkage/thresholding (TwIST) algorithm and sparse representation with the cubic B-spline function are developed to solve established normalized sparse regularization model to identify the accurate impact force and accurate peak value of the nonlinear force. Then, the identified impact force is substituted into the nonlinear response separation equation to obtain the nonlinear response part. Finally, a reduced transfer equation is established and solved by the classical Tikhonove regularization method to obtain the wave profile (variation trend) of the nonlinear force. Numerical and experimental identification results demonstrate that the novel hybrid-separate strategy can accurately and efficiently obtain the nonlinear force and impact force for the nonlinear structure.

Effects of Selenizing Modification on Characteristics and Antioxidant Activities of Inonotus obliquus Polysaccharide

Yang Hu,Shanyi Shi,Lu Lu,Chunying Teng,Sumei Yu,Xin Wang,Min Yu,Jinsong Liang,Juanjuan Qu 한국고분자학회 2017 Macromolecular Research Vol.25 No.3

Excessive reactive oxygen species is implicated in the etiology and pathology of many acute and chronic diseases. Selenium acts as an antioxidant and stimulates the creation of more antioxidants. Selenizing modification polysaccharides potentiate the physiological and pharmacological activities of selenium and polysaccharide. In this study, Inonotus obliquus polysaccharide (IOP) extracted from cultured mycelia was modified into Se-IOP by HNO3- Na2SeO3 method. The characteristics and antioxidant activity of IOP and Se-IOP were comparatively investigated. The result showed that polysaccharide content of purified IOP was 98.9%. The selenium content of Se-IOP was 0.71 mg/g. Both IOP and Se-IOP were homogeneous polysaccharides with a molecular weight of 37.354 and 28.071 kDa, respectively depicted in high performance gel permeation chromatogram (HPGPC). Moreover, both IOP and Se- IOP were composed of Man, Glu, and Gal with a molar ratio of 7.7:32.6:23.3 and 8.3:32.1:22.7, respectively determined by high performance liquid chromatography (HPLC). The characteristic absorption peak of O-Se-O, Se=O and C-O-Se appeared at 1026.75, 772.82, and 652.29 cm-1 respectively in FT-IR spectrum of Se-IOP indicating the success of selenylation. NMR spectrum further confirmed the anomeric carbon signals and chemical shifts in IOP and Se-IOP. These variations induced by selenylation may lead to a higher antioxidant activity of Se-IOP on scavenging hydroxyl, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and superoxide radical than that of IOP. Furthermore, Se- IOP treatment could also reduce oxidant damage by decreasing the level of malondialdehyde (MDA) and increasing the activities of superoxidedismutase (SOD) and GSH-Px in mice.

Soil Classification Using Near Infrared Spectroscopy and Ga-Plsda Procedure

Hongtu Xie,Jinsong Zhao,Qiubing Wang,Yueyu Sui,Jingkuan Wang,Xueming Yang,Xudong Zhang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Structural and magnetic properties of M-type Sr0.1Ca0.4La0.5Fe12O19 ferrites: The effects of CoxFe3-xO4 in precursor

Xiubin Zhao,Shuang Zhang,Jinsong Li,Ailin Xia,Yujie Yang 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.1

M-type ferrite Sr0.1Ca0.4La0.5Fe12O19 magnetic powders doped with CoxFe3-xO4 (0 ≤ x ≤ 1.25) in precursors were prepared bya ceramics process. The structure of specimens were examined by using an X-ray diffractometer. Only the magnetoplumbitephase was found in the specimens with the cobalt content (x) from 0.25 to 1.25 in precursor. The specimens exhibited a typicalhexagonal M-type structure and the particles in specimens were uniformly distributed in size. The specimen with x=1.25 hadthe maximum saturation magnetization of 67.48 emu/g, while the residual magnetization and the coercivity of the specimenwith x=1.00 reached the maximum value of 31.83 emu/g and 1270 Oe, respectively.

Formononetin-induced oxidative stress abrogates the activation of STAT3/5 signaling axis and suppresses the tumor growth in multiple myeloma preclinical model

Kim, Chulwon,Lee, Seok-Geun,Yang, Woong Mo,Arfuso, Frank,Um, Jae-Young,Kumar, Alan Prem,Bian, Jinsong,Sethi, Gautam,Ahn, Kwang Seok Elsevier 2018 Cancer letters Vol.431 No.-

<P><B>Abstract</B></P> <P>Aberrant reactions of signal transducer and transcriptional activator (STAT) are frequently detected in multiple myeloma (MM) cancers and can upregulate the expression of multiple genes related to cell proliferation, survival, metastasis, and angiogenesis. Therefore, agents capable of inhibiting STAT activation can form the basis of novel therapies for MM patients. In the present study, we investigated whether the potential anti-cancer effects of Formononetin (FT), a naturally occurring isoflavone derived from <I>Astragalus membranaceus</I>, <I>Trifolium pratense</I>, <I>Glycyrrhiza glabra</I>, and <I>Pueraria lobata</I>, against MM cell lines and human multiple myeloma xenograft tumors in athymic nu/nu mice model are mediated through the negative regulation of STAT3 and STAT5 pathways. Data from the <I>in vitro</I> studies indicated that FT could significantly inhibit cell viability, and induce apoptosis. Interestingly, FT also suppressed constitutive STAT3 (tyrosine residue 705 and serine residue 727) and STAT5 (tyrosine residue 694/699) activation, which correlated with the suppression of the upstream kinases (JAK1, JAK2, and c-Src) in MM cells, and this effect was found to be mediated <I>via</I> an increased production of reactive oxygen species (ROS) due to GSH/GSSG imbalance. Also, FT abrogated STAT3 and STAT5 DNA binding capacity and nuclear translocation. FT induced cell cycle arrest, downregulated the expression of STAT3-regulated anti-apoptotic, angiogenetic, and proliferative gene products; and this correlated with induction of caspase-3 activation and cleavage of PARP. Intraperitoneal administration of FT significantly suppressed the tumor growth in the multiple myeloma xenograft mouse model without exhibiting any significant adverse effects. Overall, our findings indicate that FT exhibits significant anti-cancer effects in MM that may be primarily mediated through the ROS-regulated inhibition of the STAT3 and STAT5 signaling cascade.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Formononetin (FT) attenuated constitutive STAT3 and STAT5 activation in MM cells <I>via</I> an increased production of reactive oxygen species (ROS) due to GSH/GSSG imbalance. </LI> <LI> FT significantly attenuated the tumor growth in the multiple myeloma xenograft mouse model without exhibiting any significant adverse effects. </LI> <LI> FT treatment also substantially downregulated the expression of STAT3 regulated gene products in tumor tissues obtained from xenograft mouse model. </LI> </UL> </P>