Effect of Argon Gas Pressure on Residual Stress, Microstructure Evolution and Electrical Resistivity of Beryllium Films

Bing-Chi Luo,Kai Li,Ji-Qiang Zhang,Jiang-Shan Luo,Wei-Dong Wu,Yong-Jian Tang 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.4

The residual stress in beryllium films fabricated on K9 substrates by using magnetron sputtering deposition is measured by using a curvature method and is theoretically estimated by using the Nix and Clemens (NC) model. The experimental results indicate that the 1.3-μm-thick film is always in a tensile state for pressure variations in the range from 0.4 to 1.2 Pa. When the sputtering gas pressure is increased, the average stress increases at first, after which it decreases by a remarkable amount. The observed descending trend of the tensile stress when the sputtering gas pressure is beyond 0.6 Pa is mainly attributed to the grain size in the film being larger than that in the film when the pressure is below 0.6 Pa. The maximal residual stress of 552 MPa at a sputtering gas pressure of 0.6 Pa is close to the tensile strength (550 MPa) of the corresponding beryllium bulk material and is about 8 times smaller than that calculated by using the N-C model. In addition, the surface morphologies of the as-fabricated films reveal fibrous grains while the cross-sectional morphologies are characterized by a coarsening of columnar grains. The measured electric resistivity of each film strongly depends on its porosity and the sizes of its grains.

Stiffness Modeling and Optimization of a 3-DOF Parallel Robot in a Serial-Parallel Polishing Machine

Peng Xu,Bing Li,Chi-Fai Cheung,Ju-Fan Zhang 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.4

Polishing is a kind of finishing process that can effectively reduce the surface defects and improve the form accuracy. This paper presents a novel hybrid machine with 6 degrees of freedom (DOF) serial-parallel topological structure used as an ultra-precision polishing equipment which is composed of a 3-DOF parallel robot, a 2-DOF serial robot and a turntable providing a redundant DOF. Due to the complexity of structure, stiffness performance evaluation of the parallel robot becomes a challenge. As a result, a theoretical model of the parallel robot based on the virtual work principle and the deformation superposition principle is formulated for analyzing the stiffness performance. With the developed model, a multi-objective dimensional optimization method is developed to maximize both the workspace volume and the global stiffness performance of the parallel robot. Artificial intelligence approach based on genetic algorithms is implemented to obtain an optimal combination of structural parameters. The effectiveness of this method is validated by simulation and the parallel robot with optimized structural parameters has a workspace with higher stiffness performance, hence justifies its suitability for high precision polishing.

Multimodal prerehabilitation for elderly patients with sarcopenia in colorectal surgery

Wu Jingting,Chi Hannah,Kok Shawn,Chua Jason M.W.,Huang Xi-Xiao,Zhang Shipin,Mah Shimin,Foo Li-Xin,Peh Hui-Yee,Lee Hui-Bing,Tay Phoebe,Tong Cherie,Ladlad Jasmine,Tan Cheryl H.M.,Khoo Nathanelle,Aw Dari 대한대장항문학회 2024 Annals of Coloproctolgy Vol.40 No.1

Sarcopenia, which is characterized by progressive and generalized loss of skeletal muscle mass and strength, has been well described to be associated with numerous poor postoperative outcomes, such as increased perioperative mortality, postoperative sepsis, prolonged length of stay, increased cost of care, decreased functional outcome, and poorer oncological outcomes in cancer surgery. Multimodal prehabilitation, as a concept that involves boosting and optimizing the preoperative condition of a patient prior to the upcoming stressors of a surgical procedure, has the purported benefits of reversing the effects of sarcopenia, shortening hospitalization, improving the rate of return to bowel activity, reducing the costs of hospitalization, and improving quality of life. This review aims to present the current literature surrounding the concept of sarcopenia, its implications pertaining to colorectal cancer and surgery, a summary of studied multimodal prehabilitation interventions, and potential future advances in the management of sarcopenia.

Comparison of Bird community in Urban and Non-Urban area at Young-San river

Jin, Seon-Deok,Bing, Gi-Chang,Park, Chi-Young,Yu, Jae-Pyung,Paik, In-Hwan,Paek, Woon-Kee,Lee, Doo-Pyo National Science Museum of Korea 2011 Journal of Korean nature Vol.4 No.3

This Study was carried out for the period from June 2003 until March 2005 aimed at comparing the characteristics of birds communities between non-urban district and urban district in the Yeongsan River basin, grasping the influence on the birds in the urban district basin, and ultimately exploring the method of preserving and managing the birds in a proper manner. The number of birds observed in this study recorded 83 species 19,322 individuals in total where the number of species were 73 in non-urban district while 71 in urban district. For the number of individuals showing larger number in urban district, 7,409 were in non-urban district while 11,913 were in urban district. For the species diversity, urban district was 2.62 while non-urban district was 3.01 showing high degree in non-urban district. For the number of individuals by bird group, Herons and Ducks were higher in the Site 6 (urban)/Site 7 (urban) while Raptors were higher in the Site 3 (non-urban) and Site 8 (urban), and Shorebirds were higher in the Site 3 (non-urban). Forest birds were found the highest in the Site 1 (non-urban), while Others higher in the Site 1 (non-urban), Site 6 (urban), and Site 8 (urban). With regard to species composition by districts, those in non-urban district consisted of Forest birds (46.1 %), Ducks (43.4%), Herons (5.3%), Shorebirds (2.6%), Others (2.2%), and Raptors (0.4%) in order of high to low composition, while urban district consisted of Ducks (75.5%), Forest birds (16.1%), Herons (5.3%), Others (2.2%), Shorebirds (0.7%), and Raptors (0.2%) in the afore-mentioned order. In result, a great difference was shown between non-urban district and urban district in the Yeongsan River basin. Accordingly when implementing environmental improvement in urban district, it is deemed necessary to do it taking the inhabiting environment of non-urban district into account in order for a stable maintenance, preservation, and management of the birds communities.

Baicalin attenuates TNBS-induced colitis in rats by modulating the Th17/Treg paradigm

Ying Zou,Shi-Xue Dai,Hong-Gang Chi,Tao Li,Zhi-Wei He,Jian Wang,Cai-Guo Ye,Guo-Liang Huang,Bing Zhao,Wen-Yang Li,Zheng Wan,Jin-Shan Feng,Xue-Bao Zheng 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.10

Baicalin, a flavonoid, has a wide range ofpharmacological properties, including immunomodulation. The objective of this study was to investigate the effect ofbaicalin on the balance of T helper 17 (Th17) and regulatoryT (Treg) cells in a colitis model. The rat colitis modelwas induced by 2,4,6-trinitrobenzene sulfonic acid(TNBS). Baicalin (10 ml/kg, each) or mesalazine (positivecontrol) was then administered orally for 7 days. Inflammatoryand immunological responses were evaluated bypathology, enzyme-linked immunosorbent assay, real-timepolymerase chain reaction, western blot analysis, and flowcytometry. Our study showed that baicalin not only significantlyattenuated TNBS-induced colitis by reducing thedisease activity index as well as macroscopic and microscopicscores, but it also improved the weight loss andshortening of the colon. Baicalin treatment also induced asignificant decrease in the levels of inflammatory mediators,including the myeloperoxidase activity, the levels oftumor necrosis factor a, IL-1b, and Th1-related cytokinesIL-12 and IFN-c. Furthermore, the beneficial effects ofbaicalin seem to be associated with regulation of the Th17and Treg paradigm. We found that administration ofbaicalin significantly downregulated the number of Th17cells and the levels of Th17-related cytokines (IL-17 andIL-6) and retinoic acid receptor-related orphan receptor ct. In contrast, there was an increase in Treg cells numbers,Treg-related cytokines transforming growth factor-b andIL-10, and forkhead box P3. Our results suggest that theanti-inflammatory effect of baicalin may be linked tomodulation of the balance between Th17 and Treg cells inTNBS-induced ulcerative colitis.

CAPTURING PASSENGERS’ VOICES

Yueh-Ling HSU,Chao-Che HSU,Pei-Chi BING 인하대학교 정석물류통상연구원 2007 인하대학교 정석물류통상연구원 학술대회 Vol.2007 No.3

This paper presents how airline passenger service requirements can be analyzed by using Kano’s model of quality element classification as well as discusses the potential benefits that can be achieved by applying this approach to make marketing strategy planning. According to Kano’s model, quality elements can be classified into three categories, namely Must-be, One-dimensional and Attractive needs, depending on their ability to create customer satisfaction or dissatisfaction. Results of this study suggest that airline passenger service elements could be classified analogously with Kano’s model to identify the most important passenger service elements. Impacts of the service elements features on passenger satisfaction or dissatisfaction have been also calculated as measurement indices for improvement.

Fabrication of polyacrylic acid-based composite binders with strong binding forces on copper foils for silicon anodes in lithium-ion batteries

Ting-Ting Su,Wen-Feng Ren,Jiang-Meng Yuan,Ke Wang,Bing-Yu Chi,Run-Cang Sun 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

The commercial application of silicon (Si) anodes with high theoretical capacity is hampered by the poorcyclic stability because the huge volume change of Si during discharge/charge processes results in thepulverization of electrode materials and the electric contact loss of electrode materials with copper(Cu) foils. Binders play an important role for adhering active materials and conductive additives togetheronto Cu foils. Herein, we design and develop a three-dimensional networked composite binder (PAA-co-SN) via an amidation reaction between polyacrylic acid (PAA) and thiourea (SN). The granular anchors(CuxS) are constructed at the interface between PAA-co-SN binders and Cu foils, resulting from the reactionof S and Cu during the drying processes of Si electrodes. When used as binders for Si nanoparticles,they exhibit stable cyclic performance (1580 mAh g1 after 500 cycles). The anchoring mechanismbetween composite binders and Cu foils provides a strategy for the improvement of electrochemicalproperties of Si-based anodes for lithium-ion batteries.