SYNTHESIS AND CHARACTERIZATION OF AU NANOPARTICLES/REDUCED GRAPHENE OXIDE NANOCOMPOSITE: A FACILE AND ECO-FRIENDLY APPROACH

MEILING ZOU,HAN ZHU,PAN WANG,MINGLIANG DU,MING ZHANG,SHIYONG BAO 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.3

In this paper, epigallocatechin gallate (EGCG) was used as a green reductant both for thefabrication of soluble reduced graphene oxide (rGO) and the synthesis of Au nanoparticles/rGOnanocomposite. Fourier transform infrared (FTIR) spectra con¯rmed the e±cient removal of theoxygen-containing groups in graphene oxide (GO) through the reduction act of EGCG. Aunanoparticles (AuNPs) were anchored onto the rGO sheets by heating the mixed solution of rGOand chloroauric acid at 65?C using EGCG as reductant. Transmission electron microscopy(TEM), atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) wereemployed to characterize the resulting nanocomposite. Due to the chelating e®ect of polyhydroxyEGCG, AuNPs with diameters of ? 20 – 50 nm were stably decorated onto both sides of the rGOsheets. Because this reduction method avoids the use of toxic reagents, AuNPs/rGO nano-composite would be eco-friendly, and it might be useful not only for electronic devices but also forbiocompatible materials in the future applications.

Analysis for Stress Characteristics and Structural Parameters Optimization in Orthotropic Steel Box Girders based on Fatigue Performance

Meiling Zhuang,Changqing Miao,Rongfeng Chen 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.6

A fatigue design method for the orthotropic steel deck bridges is proposed. The stress characteristics of welded details are analyzed using the finite element method. Based on the fatigue performance, the structural parameters of the orthotropic steel decks (OSDs) are optimized using the combination BP (back propagation) neural network and genetic algorithms (GA). The calculated results demonstrate that the weld stresses at the deck plate-to-rib, deck plate-to-rib-to-diaphragm welded details are mainly bending stress while those at the rib-to-rib welded details are mainly membrane stress. The fatigue stress of each weld is deeply affected by the transverse and longitudinal direction positions. The local effect of stress distribution of all welded details is remarkable. The calculated results obtained using the proposed model are in good agreement with those obtained using ANSYS and the errors are within 5%. The optimal structural results are highly influenced by the applied wheel loadings, while the optimal results for the deck thickness and the U-rib opening size are highly influenced by temperature. Especially on the ordinary lane, temperature has a great effect on the fatigue performance for all welded details.

Experimental study on repair of corroded steel beam using CFRP

Meiling Chen,Sreekanta Das 국제구조공학회 2009 Steel and Composite Structures, An International J Vol.9 No.2

It has been reported that more than thirty five percent of steel bridges in the USA are structurally deficient because of structural degradations. The degraded structures need either full replacement or rehabilitation such that they are able to provide the required services for a longer period of time. The cost for repair in most cases is far less than the cost of replacement. Moreover, repair method generally takes less time than replacement and also reduces service interruption time. Modern advanced composites have been used in aerospace and automotive fields since World War II. In the recent past, because of the high strength-to-weight ratio and high stiffness-to-weight ratio, these composite materials have been introduced to civil engineering infrastructures primarily for repair and rehabilitation of concrete structures. However, only a few preliminary studies on repair of corroded steel structures using theses composite materials are reported in the literature available in the public domain. Thus, in this study, a series of laboratory tests was undertaken to evaluate the effectiveness of this repair method using carbon fiber reinforced polymer composite. The paper discusses the test method and test results obtained from these tests.

Preparation of array micro-holes with large aspect ratio in ZL102

Meiling Jin 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

In the past research work, a new preparation of array micro-holes on pure aluminum was proposed. However, in the practical application, most of them are alloys. Therefore, it is very necessary to explore the feasibility of the method in the application of alloys. In the process, in order to protect shape of micro-hole, metal wires coated with graphite paint are selected as the hole cores. Aiming at demonstrating the quality of array micro-holes, the aspect ratio, roughness and roundness of array micro-holes are researched. The results show that the casting process of micro-holes is suitable for ZL102 alloy, and the roughness and the shape factor of micro-hole is 6.85 μm and 0.98. The silicon element in the alloy is ability of reducing viscosity and surface tension of melt molten, which is improving filling ability of melt molten. So, parameters of micro-hole, including aspect ratio, roughness and roundness, are better than that of pure aluminum.

원자력발전소에서 상사의 직무지시방식이 직무수행도 및 에러발생률에 미치는 영향

Meiling Luo,Yong-Hee Lee 대한인간공학회 2013 대한인간공학회 학술대회논문집 Vol.2013 No.5

조직의 계층에 따라 상사는 하향적으로 부하직원에게 직무지시를 하게 된다. 하향적 의사소통은 조직의사소통 유형 중의 하나로서, 상사로부터 부하에게 의사와 정보를 전달하게 된다. 기존 직무를 수행 중이었던 부하직원은 직무를 중단하고, 상사가 지시하는 직무를 우선적으로 진행하게 된다. 원자력발전소에서는 이와 같은 운선순위의 발생으로 인해 인적 오류가 발생할 수 있는지 우려가 되며, 이런 추가 직무지시가 직무수행도에 미치는 영향에 대한 연구가 필요하다. 따라서 본 연구에서는 단순확인기록작업을 기본직무로 하고, 상사가 부하직원에게 추가직무로 확인 및 판단직무를 주는 실험을 실시하였다. 직무지시방식은 추가직무를 ‘한꺼번에’ 시키는 방법과, ‘여러 번 나누어’ 시키는 방법으로 분류하고, 정신적인 작업부하를 NASA-TLX, 직무수행도에 대하여서는 직무 오답률 및 직무 수행시간을 측정하였다. 실험결과, ‘한꺼번에’ 추가직무를 주는 방법이 부하직원에 있어서 정신적 작업부하가 낮고, 직무 수행시간이 짧게 나타났지만, 이와 반대로 직무 오답률이 높게 나타났다. 본 연구에서는 추가직무에 대한 지시방법에 중점을 두고, 이런 추가직무의 지시방식을 효과적으로 다루어 인적 오류의 문제를 해결하며, 보다 높은 직무수행도를 갖추고자 하였다.

Magnetically-separable and Highly-stable Enzyme System based on Crosslinked Enzyme Aggregates Shipped in Magnetite-coated Mesoporous Silica

Meiling Zhang,Seung-Hyun Jun,Byoungsoo Lee,Jungbae Kim 한국생물공학회 2011 한국생물공학회 학술대회 Vol.2011 No.4

On-surface synthesis by C-X bond activation

Meiling BAO,Qiang SUN,Wei XU 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Maximizing the Beauty of Ceramic Art Application in Landscape Design under the Background of Artificial Intelligence

Meiling Wang 한국멀티미디어학회 2023 The journal of multimedia information system Vol.10 No.4

With the large-scale development of urban landscaping construction, the problems in its expression of beauty are gradually emerging. This article selects the beauty of ceramic art in landscape design, which combines complexity and ambiguity, as the research object and conducts a systematic study on its aesthetic evaluation. Ceramic artists use pattern content to express their attitude towards life and pursuit of art. But ce-ramic art creation is difficult and highly professional, making it difficult for non-professionals to get started. Against the backdrop of the rapid development of artificial intelligence, image analysis technology has emerged, allowing non-professionals to decorate ceramic products. In this study, the extraction, quantification, and recognition of ceramic features are carried out through machines. The idea and implementation method of replacing experts with machines for intelligent ceramic recognition are explored. Traditional models such as Convolutional Neural Network (CNN), Visual Geometry Group (VGG) network, and fast migration model are introduced, and the improved fast migration model are pro-posed. Finally, through experimental comparison, the results show that the improved fast migration model exhibits robust changes in extrac-tion quality as the learning amount increases, and has generalization ability. It is an effective new method for achieving ceramic aesthetic re-search and analysis, and has good practicality

VIBRATION OF MISALIGNED ROTOR SYSTEM AND UNVEVEN LOADS ON BEARINGS

Meiling Wang,Hao Zhang,Guang Zhao,Qingkai Han,Tianmin Guan 한국신재생에너지학회 2013 AFORE Vol.2013 No.-

Silage preparation and fermentation quality of natural grasses treated with lactic acid bacteria and cellulase in meadow steppe and typical steppe

Meiling Hou,Ge Gentu,Tingyu Liu,Yushan Jia,Yimin Cai 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.6

Objective: In order to improve fermentation quality of natural grasses, their silage preparation and fermentation quality in meadow steppe (MS) and typical steppe (TS) were studied. Methods: The small-scale silages and round bale silages of mixed natural grasses in both steppes were prepared using the commercial lactic acid bacteria (LAB) inoculants Chikuso-1 (CH, Lactobacillus plantarum) and cellulase enzyme (AC, Acremonium cellulase) as additives. Results: MS and TS contained 33 and 9 species of natural grasses, respectively. Stipa baicalensis in MS and Stipa grandi in TS were the dominant grasses with the highest dry matter (DM) yield. The crude protein (CP), neutral detergent fiber and water-soluble carbohydrate of the mixed natural grasses in both steppes were 8.02% to 9.03%, 66.75% to 69.47%, and 2.02% to 2.20% on a DM basis, respectively. All silages treated with LAB and cellulase were well preserved with lower pH, butyric acid and ammonia-N content, and higher lactic acid and CP content than those of control in four kinds of silages. Compared with CH- or AC-treated silages, the CH+ AC-treated silages had higher lactic acid content. Conclusion: The results confirmed that combination with LAB and cellulase may result in beneficial effects by improving the natural grass silage fermentation in both grasslands.