Failure Mode of Orthotropic Two-way Composite Slab under Concentrated Load

Yulin Zhan,Wenfeng Huang,Yu Qiao,Zhouyuan Xu,Renda Zhao 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.12

Ordinary reinforced concrete two-way slabs generally suffer from punching failure under concentrated loads, which is a brittle failure and unfavorable to the structures. The composite slabs with steel sheets and PBL (perfobond rib) shear connectors have been applied for reducing the damage to bridge decks from vehicles. Although it is widely used on bridges, the failure mode of the orthotropic two-way composite slabs has rarely been studied when subject to concentrated loads. Accordingly, static loading tests with concentrated forward central load was carried out on 4 two-way composite slabs, in which the effects of the thickness of steel bottom sheets and concrete plates and spacing of PBL shear connectors on mechanical properties were investigated. The test results show that about 12% of the ultimate bearing capacity decreases when the perfobond ribs are spaced farther apart from 180 mm to 240 mm or the thickness of steel bottom sheets is reduced from 10 mm to 8 mm. And the bearing capacity drops by 38.2% when the thickness of concrete plates decreases by 30 mm. The steel-concrete composite slabs exhibit clear bidirectional force characteristics during the loading process, with the main forced direction being along the perfobond ribs, which is related to the stiffness ratio of the two directions. The two-way composite slabs have high bearing capacity and ductility, with obvious signs before failure. The specimens continue to bear the load after local punching failure of concrete near the loading point, which shows the features of both bending and punching failure. Based on the test results, a bending punching failure mode is proposed, which provides a new approach for the calculation of ultimate bearing capacity. An analytical calculation method for ultimate bearing capacity of orthotropic two-way composite slabs based on the failure mode above is derived with yield line theory and plastic theory, which is in excellent agreement with the tested results.

Plasmonic Periodic Nanodot Arrays <i>via</i> Laser Interference Lithography for Organic Photovoltaic Cells with >10% Efficiency

Oh, Yulin,Lim, Ju Won,Kim, Jae Geun,Wang, Huan,Kang, Byung-Hyun,Park, Young Wook,Kim, Heejun,Jang, Yu Jin,Kim, Jihyeon,Kim, Dong Ha,Ju, Byeong-Kwon American Chemical Society 2016 ACS NANO Vol.10 No.11

<P>In this study, we demonstrate a viable and promising optical engineering technique enabling the development of high-performance plasmonic organic photovoltaic devices. Laser interference lithography was explored to fabricate metal nanodot (MND) arrays with elaborately controlled dot size as well as periodicity, allowing spectral overlap between the absorption range of the active layers and the surface plasmon band of MND arrays. MND arrays with,-,91 nm dot size and similar to 202 nm periodicity embedded in a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) hole transport layer remarkably enhanced the average power conversion efficiency (PCE) from 7.52% up 10.11%, representing one the highest PCE and degree of enhancement (similar to 34.4%) levels compared to the pristine device among plasmonic organic photovoltaics reported to date. The plasmonic enhancement mechanism was investigated by both optical and electrical analyses using finite difference time domain simulation and conductive atomic force microscopy studies.</P>

Plasmonic nanodot array via laser interference lithography for > 10 % efficiency organic photovoltaic cells

임주원,( Yulin Oh ),( Jae Geun Kim ),( Young Wook Park ),( Heejun Kim ),( Yu Jin Jang ),( Jihyeon Kim ),( Byeong Kwon Ju ),김동하 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Metallic nanodots (MNDs) have been widely utilized for the development of high-performance organic photovoltaic (OPV) cells by amplifying light absorption at the active layer. In this study, promising optical engineering which enables the development of high-performance OPV was demonstrated. We elaborately control the size and periodicity of the MND arrays via laser interference lithography. The MND arrays can induce the spectral overlap between the absorption range of the organic semiconductors and the plasmon resonance of MNDs. As a results, MND arrays led to a remarkable enhancement in power conversion efficiency up to 10.55 % from 7.2 % compared with control device. Near field enhancement and light scattering effect are responsible for the significantly improved device performance.

Nitrogen self-doped porous carbon nanosheets derived from azo dye flocs for efficient supercapacitor electrodes

Wei Tingting,Wu Liang,Yu Feng,Lv Yin,Chen Long,Shi Yulin,Dai Bin 한국탄소학회 2019 Carbon Letters Vol.29 No.5

The present work introduces a new method for the recycling of waste flocculation sludge to prepare electrode materials for supercapacitor. Hazardous azo dye was removal from textile dying wastewater by a new chitosan-based flocculant, and the generated dye sludge flocs was used as a nitrogen-containing precursor for the fabrication of N-doped carbon materials. The influence of azo dye on specific surface areas, nitrogen content, pore evolution of the resulting products and their electrochemical performance were investigated in detail. The results demonstrated a dual role of azo dye worked as both a nitrogen resource and pore-forming agent. The resulting N-doped carbon nanosheets derived from azo dye flocs demonstrated high electrochemical capacitance and good stability for supercapacitor electrode, which is attributed to the unique nitrogen doping, higher specific surface area and efficient charge transfer ability.

Flexural Durability and Chloride Diffusion Equation of TRC-Strengthened Beams under a Chloride Environment

Shiping Yin,Yuntao Hua,Yulin Yu 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.6

In this study, the chloride ion diffusion and structural performance of beams reinforced with textile-reinforced concrete (TRC) were evaluated. The parameters investigated were chloride concentration, sustained load and number of textile layers. The results demonstrate that the content and diffusion coefficient of chloride increased with increasing chloride concentration. Higher chloride concentrations accelerated the crack propagation and deflection changes and caused the reduction of the load-carrying capacity of the beams. The sustained load promoted the chloride transport of the TRC, increasing the chloride ion content and diffusion coefficient and causing substantial damage to the microstructure of the TRC. In addition, the performance (such as cracking resistance, deflection and flexural capacity) of beams with a large sustained load ratio decreased to a less extent than did the performance of the unloaded beams. The content and diffusion coefficient of chloride in the unstrengthened beams were obviously larger than those in the strengthened beams, but increasing the textile layers number had little influence on these factors. In addition, for the unstrengthened beams, the cracks and deflections developed rapidly, and the load decreased greatly, especially the cracking load. Finally, in accordance with Fick’s second law of diffusion, a chloride diffusion equation in TRC layers under new boundary conditions was proposed.

Nitrogen self‑doped porous carbon nanosheets derived from azo dye flocs for efficient supercapacitor electrodes

Tingting Wei,Liang Wu,Feng Yu,Yin Lv,Long Chen,Yulin Shi,Bin Dai 한국탄소학회 2019 Carbon Letters Vol.29 No.5

The present work introduces a new method for the recycling of waste flocculation sludge to prepare electrode materials for supercapacitor. Hazardous azo dye was removal from textile dying wastewater by a new chitosan-based flocculant, and the generated dye sludge flocs was used as a nitrogen-containing precursor for the fabrication of N-doped carbon materials. The influence of azo dye on specific surface areas, nitrogen content, pore evolution of the resulting products and their electrochemical performance were investigated in detail. The results demonstrated a dual role of azo dye worked as both a nitrogen resource and pore-forming agent. The resulting N-doped carbon nanosheets derived from azo dye flocs demonstrated high electrochemical capacitance and good stability for supercapacitor electrode, which is attributed to the unique nitrogen doping, higher specific surface area and efficient charge transfer ability.

Enhanced electrochemical performances of LiNi0.5Co0.2Mn0.3O2 cathode material co-coated by graphene/TiO2

Dang Mengyue,Li Ying,Xu Chaoxiang,He Yulin,Yu Chunpeng,Liu Wenbo,Jin Hongming,Zhu Mingyuan,Zhang Jiujun,Li Wenxian 한국물리학회 2021 Current Applied Physics Vol.32 No.-

The electrochemical performances of LiNi0.5Co0.2Mn0.3O2 (NCM523) layered cathode material, such as poor rate capacity and cycling stability caused by undesirable intrinsic conductivity and low rate of lithium ion transportation, are not fairly good especially at elevated rate and cut-off voltage. To improve these properties, in this study, the co-coating layer of graphene and TiO2 was constructed on NCM523 surface. The graphene/TiO2 coating layer could effectively prevent hydrofluoric acid (HF) attacks, suppress the side reaction, accelerate the lithium ion diffusion and facilitate the electron migration. The enhancement of cycle performance and rate capacity was contributed to the uniform co-modified surface, interacting each other and thus exhibiting synergistic effects.

Role of Estrogen Receptor-α in the Regulation of Claudin-6 Expression in Breast Cancer Cells

Liu Yafang,Wu Qiong,Ren Yue,Xu Xiaoming,Yu Lina,Zhang Mingzi,Zhang Ting,Li Yulin,Quan Chengshi 한국유방암학회 2011 Journal of breast cancer Vol.14 No.1

Purpose: In our previous studies we showed that upregulating claudin-6 (CLDN6) expression may contribute to preventing breast cancer, and that 17β-estradiol induces a concentration- and time-related effect on CLDN6 mRNA and protein expression in MCF-7 cells. However, the mechanisms of 17β-estradiol regulation of CLDN6 are still unclear. We determined the role of estrogen receptors in the regulation of CLDN6 expression in human breast cancer tissues and a cell line. Methods: CLDN6, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) expression in breast cancer tissues were examined using immunohistochemistry. The human breast cancer cell line, MCF-7, which expresses ERα but not ERβ was used. CLDN6 and ERα expression were measured by reverse transcriptase-PCR, Western blotting and immunofluorescent staining. Treatments with propyl pyrazole triol (PPT) and ICI 182, 780 (ICI) were performed. Results: The results revealed that CLDN6 expression was related to ERα in breast cancer tissues (p=0.033). PPT, an ERα-selective ligand, upregulated CLDN6 expression at 10^(-5) mol/L after 24 hours. The effect of PPT on regulating CLDN6 expression in MCF-7 cells was blocked by ICI. Conclusion: These findings suggest that Erα reulates CLDN6 expression in breast cancer tissues and that 17β- estradiol induces CLDN6 expression through an ERα pathway in MCF-7 cells.

Characterization of Newcastle disease virus obtained from toco toucan

Jiaxin Li,Mengmeng Ling,Yixue Sun,Haiyang Di,Yulin Cong,Haiying Yu,Yanlong Cong 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.2

Given that the current Newcastle disease virus (NDV) infection in wild birds poses the threat to poultry, surveillance of Newcastle disease in captive wild birds was carried out in Jilin, China in 2018. Here, an NDV strain obtained from toco toucan was firstly characterized. The results showed that the F gene of the NDV isolate Toucan/China/3/2018 is classified as genotype II in class II. Sequence analysis of the F0 cleavage site was 113RQGR/L117, which supports the result of the intracerebral pathogenicity index assay indicating classification of the isolate as low-pathogenicity. Experimental infection demonstrated that Toucan/China/3/2018 can effectively replicate and transmit among chickens. To our knowledge, this is the first report on genetically and pathogenically characterizing NDV strain isolated from toucan, which enriches the epidemiological information of NDV in wild birds.

Effect of Phosphodiesterase-5 Inhibitors on the Treatment of Male Infertility: A Systematic Review and Meta-Analysis

Dong Liang,Zhang Xiaojin,Yan Xuhong,Shen Yifeng,Li Yulin,Yu Xujun 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.4

Purpose: Male infertility is a worldwide problem with limitations in the treatment. Phosphodiesterase-5 inhibitors (PDE5is) is the first choice for the treatment of erectile dysfunction, more and more studies show that it has a certain effect on male infertility in recent years. But there was currently no high quality of systematic review to evaluate the effects of PDE5is on semen quality. Materials and Methods: We retrieved the electronic databases of MEDLINE, PubMed, Web of Science, EMBASE, etc. Related randomized controlled trials (RCTs) were collected and selected up to May 20, 2020. We have searched literature with terms “male infertility”, “phosphodiesterase-5 inhibitors”, “PDE5i”, “Tadalafil”, “Sildenafil”, “Vardenafil”, “Udenafil”, “Avanafil”, “semen”, and “sperm”. Mean value and its standard deviation were used to perform quantitative analysis. All statistical analyses were conducted by RevMan 5.3 and Stata software. Results: There were a total of 1,121 participants in the nine included studies. There was a statistically significant improvement treated with PDE5is compared with sham therapy, which including sperm concentration (mean difference [MD]=1.96, 95% confidence interval [CI]=1.70–2.21, p<0.001; MD=3.22, 95% CI=1.96–4.48, p<0.001), straight progressive motility (%) Grade A (MD=3.71, 95% CI=2.21–5.20, p<0.001), sperm motility (MD=8.09, 95% CI=7.83–8.36, p<0.001), morphologically normal spermatozoa (%) (MD=0.67, 95% CI=0.20–1.15, p=0.005; MD=1.27, 95% CI=0.02–2.52, p=0.05), sperm abnormalities (%) (MD=-0.64, 95% CI=-0.81–-0.47, p<0.001), and progressive motile sperm (MD=5.34, 95% CI=3.87–6.81, p<0.001). Conclusions: In this meta-analysis of nine RCTs, treatment with PDE5is could improve some indicators of male sperm.