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Biaxial stretching of polytetrafluoroethylene in industrial scale to fabricate medical ePTFE membrane with node-fibril microstructure

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regenerative Biomaterials 2023年第1期10卷 1161-1177页

作者： Gang Wang Yusheng Feng Caiyun Gao Xu Zhang Qunsong Wang Jie Zhang Hongjie Zhang YongqiangWu Xin Li Lin Wang Ye Fu Xiaoye Yu deyuan Zhang Jianxiong Liu Jiandong ding State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China R&D Center Lifetech Scientific(Shenzhen)Co.Ltd.Shenzhen 518057China R&D Center Lifevalve Medical Scientific Co.Ltd.Shenzhen 518057China

Expanded polytetrafluoroethylene(ePTFE)is promising in biomedical fields such as covered stents and plastic surgery owing to its excellent biocompatibility and mechanical ***,ePTFE material prepared by the traditional biaxial stretching process is with thicker middle and thinner sides due to the bowing effect,which poses a major problem in industrial-scale *** solve this problem,we design an olive-shaped winding roller to provide the middle part of the ePTFE tape with a greater longitudinal stretching amplitude than the two sides,so as to make up for the excessive longitudinal retraction tendency of the middle part when it is transversely *** as-fabricated ePTFE membrane has,as designed,uniform thickness and node-fibril *** addition,we examine the effects of mass ratio of lubricant to PTFE powder,biaxial stretching ratio and sintering temperature on the performance of the resultant ePTFE ***,the relation between the internal microstructure of the ePTFE membrane and its mechanical properties is *** stable mechanical properties,the sintered ePTFE membrane exhibits satisfactory biological *** make a series of biological assessments including in vitro hemolysis,coagulation,bacterial reverse mutation and in vivo thrombosis,intracutaneous reactivity test,pyrogen test and subchronic systemic toxicity test;all of the results meet the relevant international *** muscle implantation of the sintered ePTFE membrane into rabbits indicates acceptable inflammatory reactions of our sintered ePTFE membrane fabricated on industrial *** a medical-grade raw material with the unique physical form and condensed-state microstructure is expected to afford an inert biomaterial potentially for stent-graft membrane.

关键词： biomedical polymer medical-grade raw material expanded polytetrafluoroethylene olive roller polymer processing biaxial stretching

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A Biosurfactant-containing TSd Strategy to Modify Bovine Pericardial Bioprosthetic Valves for Anticalcification

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Chinese Journal of Polymer Science 2023年第1期41卷 51-66页

作者： Cai-Yun Gao Gang Wang Lin Wang Qun-Song Wang Han-Cheng Wang Lin Yu Jian-Xiong Liu Jian-dong ding State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai200438China R&D Center Lifetech Scientific(Shenzhen)Co.Ltd.Shenzhen518057China R&D Center Lifevalve Medical Scientific Co.Ltd.Shenzhen518057China

Bioprosthetic heart valves(BHVs)are important for transcatheter valve *** commercial BHVs on the market are basically porcine or bovine pericardium(BP)crosslinked with glutaraldehyde(GA).Simply applying GA to BHVs can enhance mechanical stability,but cannot alleviate in vivo *** this work,we developed a two-step decellularization(TSd)strategy to modify this biomacromolecular network,in which BP was post-treated,as the second step of decellularization,with a mild biosurfactant n-dodecyl-β-d-maltoside in a mixture of isopropanol and phosphate-buffered saline after the first step of traditional decellularization and GA *** TSd-treated BP exhibited not only low cytotoxicity and excellent mechanical properties in vitro,but also low immune responses and significant anticalcification in *** 60 days of subcutaneous implantation in the back of Wistar rats,the calcium content was,as quantified with an inductively coupled plasma optical emission spectrometer,only 1.1µg/mg compared to 138.6µg/mg in the control group without the *** addition,collagen fibrils were observed with field emitting scanning electron microscopy(SEM),and the morphology and composition of the calcified sites resulting from in vivo biomineralization were studied with SEM with energy dispersive spectroscopy and also X-ray *** study proposes a facile yet effective anticalcification strategy for the modification of the bovine pericardial bioprosthetic heart valve,a natural biomacromolecular network.

关键词： Heart valve Anticalcification Collagen In vivo biomineralization Transcatheter aortic valve implantation(TAVI) Extracellular matrix Biomacromolecular network Biosurfactant Bovine pericardium

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Comparison of tissue response and lifting effect induced by non-absorbable elastic thread and commercialized threads in rat model

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regenerative Biomaterials 2025年第1期4卷 84-93页

作者： dae Hyung Lee Yeji Choi Mi Hee Lee Jong-Chul Park Advanced Medical Device R&D Center HansBiomed Co.LtdSeoul 05836Republic of Korea Cellbiocontrol Laboratory Department of Medical EngineeringYonsei University College of MedicineSeoul 03722Republic of Korea

As we age,our skin loses elasticity and wrinkles *** prevent this,most people try to improve skin wrinkles by performing procedures such as fillers,and absorbable lifting *** way to solve this structural problem is to use an elastic *** elastic sutures made of polymer materials(such as silicone)are widely used,data regarding their properties and potential effectiveness are *** study aimed to investigate the effects of inserting non-absorbable elastic threads,with different manufacturing requirements and methods,on the skin and subcutaneous *** this study,non-absorbable elastic threads ELATENS and Elasticum using different manufacturing methods were *** thread was transplanted into the subcutaneous layer of the back of a rat to induce *** inducing wrinkles in the skin of rat,the degree of skin maintenance by each thread and the thickness of the capsule formed around the suture were *** ex-vivo experiments on each thread,the fixation force in the tissue was *** a comparison of inflammatory response and collagen formation through histological analysis,it was confirmed that there was no significant difference from the equivalent comparative *** conclusion,the degree of encapsulation between tissues and collagen fiber formation for improving skin wrinkles was superior in elastic threads compared to non-elastic *** is believed that this provides certain elasticity to the skin layer and can induce cell influx to improve wrinkles.

关键词： elasticity lifting rejuvenation suture thread

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Improvement of Maglev Guideway Functional Plane deviation Measurement Method Based on Image recognition Technology 24

Improvement of Maglev Guideway Functional Plane Deviation Me...

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24th COTA International Conference of Transportation Professionals: resilient, Intelligent, Connected, and Lowcarbon Multimodal Transportation, CICTP 2024

作者： Fei, Peng Long, Peng Feng, Ye National Maglev Transportation Engineering R&D Center Tongji Univ. Shanghai China

ISBN: (数字)9780784485484

ISBN: (纸本)9780784485484

The guideway functional plane is a crucial component of high-speed maglev transit. due to factors like construction activities nearby, the maglev line’s piers and columns may be dislocated, resulting in additional local deviations on its guideway functional plane, posing safety risks. The traditional approach of deploying monitoring points on the guideway functional plane is unrealizable due to the clearance limit. The current solution uses pier displacement as an alternative to the deviation of the guideway functional plane. relevant research data shows this method can’t satisfy the accuracy requirement. This study adopts an indirect measurement method based on image recognition technology. relative displacement data between the girder and pier of the maglev line is obtained. The results demonstrate that image recognition-based indirect measurement method is simple and effective. The measured data would provide the basis for investigating the laws of deformations between the superstructure and substructure of the maglev track system. © ASCE.

关键词： Guideways

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Energy and Exergy Analysis of a Biodiesel Plant 36

Energy and Exergy Analysis of a Biodiesel Plant

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36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2023

作者： Barbosa, Flavia V. Mendes, Paulo r.S. Castro, Carlos Teixeira, Senhorinha F.C.F. Teixeira, José C.F. MEtRICs R&D Center University of Minho School of Engineering Guimarães Portugal ALGORITMI R&D Center University of Minho School of Engineering Guimarães Portugal

ISBN: (纸本)9781713874928

despite the current push for full electrification of the transportation sector, the utilization of IC engines (either on their own or hybrid guise) will continue for the foreseeable future. This is even more evident in the freight industry and with construction equipment. Therefore, the use of alternative fuels is a vital stepping stone toward low-carbon transportation. Environmental regulations have been developing enormous interest in biodiesel as an alternating fuel, with the main objective of reducing emissions associated with the transportation sector. Biodiesel is a renewable fuel that is mainly produced from vegetable oils and animal fats. At an industrial scale, its production is an energy-intensive operation that contributes to the overall carbon footprint. The present paper describes the energy and exergy analysis of an existing biodiesel plant. The facility applies used cooking oils and vegetable oils as raw materials and has an annual consumption of over 1,100 toe (as of 2021). The analysis identified the possibility of using biomass as a primary energy source for heat. Furthermore, the detailed analysis of the plant operation enables the identification of energy conservation measures that can reduce the electricity consumption and the pellet consumption by 29 tons a year. © (2023) by ECOS 2023 All rights reserved.

关键词： Biodiesel

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Oxoammonium salt mediated conversion of cyclohexylamine toward cyclohexanone with water as the oxygen source

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Green Chemical engineering 2025年第3期6卷 365-371页

作者： ruan, Yuting Wang, Yongtao Yao, Jia Li, Haoran Department of Chemistry Zhejiang University Hangzhou310058 China Center of Chemistry for Frontier Technologies ZJU-NHU United R&D Center Hangzhou310058 China State Key Laboratory of Chemical Engineering and College of Chemical and Biological Engineering Zhejiang University Hangzhou310058 China

Cyclohexylamine is a key byproduct during the production of cyclohexanone oxime, which is an important bulk chemical in material industry. Here we report a highly efficient approach to oxidize cyclohexylamine toward cyclohexanone with oxoammonium salt as the oxidant and water as the oxygen source, which has non-involvement of metal catalyst. The obtained cyclohexanone is an important raw material for both cyclohexanone oxime and adipic acid production. On basis of control experiments, mass spectrometry, and product analysis, the essential role of water as oxygen source and the reaction mechanism were elucidated. Moreover, the recycling of the oxoammonium salt succeeded to convert another proportion of the substrate. These findings offer new insights and methods for the oxidative conversion of cyclohexylamine. © 2024 Institute of Process engineering, Chinese Academy of Sciences.

关键词： Water recycling

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Stability Assessment of the Surrounding Areas of the Powerhouse at the damo Hydropower Station

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ce/papers 2025年第2期8卷 463-470页

作者： Wang, Jingyong Wang, Xiaohong Cheng, Yongjin Chu, Weijiang Wang, Can Power China Huadong Engineering Co. Ltd Hangzhou311122 China Hydro-China Itasca R&D Center Hangzhou311122 China

The damo Hydropower Station, a critical infrastructure facility, requires a thorough stability assessment to ensure its safe operation and reliability. This paper presents a comprehensive investigation of the powerhouse area's stability, focusing on the geological and hydrogeological conditions, existing deformations, and their underlying causes and trends. The damo station's vicinity to active and historical coal mining regions, particularly the K7, K8, and K10 seams, poses significant challenges to its structural stability. The research employs the Mohr-Coulomb plastic model in FLAC3d and UdEC simulations to scrutinize the deformation induced by mining activities. Key findings indicate that subsidence is the primary deformation type, with the powerhouse area experiencing cumulative horizontal and vertical displacements, highlighting the need for continuous monitoring and risk management. The study concludes with an anticipated subsidence of 0.90 to 1.25 meters and suggests enhanced monitoring and strategic risk control measures, especially for the pressure pipeline, to ensure the long-term integrity of the damo Hydropower Station. © 2025 Ernst & Sohn GmbH.

关键词： risk management

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Latest Technological Progress in drilling and Completion Operations of the Unconventional reservoir in Xinjiang MaHu Oil Field and Key Suggestions for the Next Steps

Latest Technological Progress in Drilling and Completion Ope...

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2025 International Petroleum Technology Conference, IPTC 2025

作者： Hu, Huaigang Xi, Chuanming Ji, Guodong Zhang, Nan Wu, Qiang Zhuo, Lubin Zou, Lingzhan CNPC Engineering Technology R&D Company Limited Beijing China National Engineering Research Center for Oil Gas Drilling and Completion Technology Beijing China Xinjiang Oilfield Engineering Technology R&D Company Limited Karamay China

ISBN: (纸本)9781959025436

due to the differences in sedimentary environments, compared with the exploitation of unconventional oil and gas resources in the United States and other countries, China has encountered greater difficulties in the drilling and completion processes of unconventional oil and gas. By analyzing the problems faced by drilling and completion in unconventional reservoirs in the MaHu area in recent years, the process of solving the issues and technical progress are summarized to form a technical template for drilling and completion in this area, which can also provide references for the next step to improve the drilling efficiency and reduce development costs. By studying the lateral distribution law of the pore pressure, the placement of the technical casing was optimized to further develop a standard design for the wellbore structure applicable to this area. To adapt to the local environmental protection requirements, high-performance non-sulfonic treatment agents were selected to replace sulfonic treatment agents, and four sets of environmental protection drilling fluid systems were formed. Based on the rock mechanics and field tests, the personalized drill bit is continuously optimized. With the introduction of a rotary steering drilling system and high-performance positive displacement motor (PdM), the rate of penetration (rOP) has been greatly improved. The transformation of horizontal Wells in the target Triassic formation from four types of casing strings with open hole completion + White oil-based/potassium-calcium based polysulfone organic salt drilling fluid to three types of casing strings with 5-inch casing completion + white-oil/potassium-calcium polyamine organic salt drilling fluid, from conventional rotary drilling + roller cone bit to rotary steering system/high-performance PdM +PdC bit, and the horizontal section length increased from 2000m to 2650m. Completion time decreased from an average of 144 days to 72 days. Speak of the Permian formation, the tra

关键词： Oil well completion

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research on welding deformation control technology of battery electric vehicle framed aluminum body

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Progress in Natural Science:Materials International 2024年第1期34卷 108-121页

作者： Bo Liu Jian Yang Jia Li Xiaolin Liao Qin Yang Jinsheng Zhang Tiegang Hu Shuxun Jiang School of Mechanical Engineering University of Science and Technology Beijing Chongqing Industry Polytechnic College Global R&D Center Chongqing Changan Automobile Co. Ltd Farizon New Energy Commercial Vehicle Group

The welding process of aluminum(Al) alloy car body has problems such as poor weld quality, low welding co-efficient, and large welding deformation. This paper mainly focuses on material accuracy design, lap structure design, simulation, and process manufacturing to break through the precision control problems caused by welding deformation of battery electric vehicle Al alloy car body. First, the 209 key functional dimensional chains of Al body-in-white are analyzed and decomposed to component and profile tolerance dimensions step by ***, the differences of vertical butt, bevel butt, and plug structures are studied and joint matching is implemented in a targeted manner. Subsequently, through welding deformation simulation analysis and welding sequence optimization, the body-in-white welding process and tooling fixtures are guided and designed to ensure that the dimensional accuracy of the Al body is controlled to ±2 mm in all aspects. Finally, the design of the whole vehicle arrangement of mechanical, human-machine, and major components is carried out, and an all-Al framed battery electric vehicle lightweight platform with different sizes and ranges is innovatively created. The difficulties such as the contradiction between power battery size and arrangement space, unreasonable arrangement position, and load distribution are solved.

关键词： Aluminum alloy Frame structure Welding deformation simulation dimensional accuracy control Battery electric vehicle lightweight platform

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Halophobic Prussian blue analogue electrodes for saturated saline water electrolysis

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Nano research 2025年第3期18卷 90-97页

作者： Wei Liu Jiage Yu Boyu ding Tianshui Li Shihang Li Xinlong Guo Linlin Zhou Benqiang Tian Yixin Zhang Yizhe Li Mengze Ma Kairui Wang Huijun Xin daojin Zhou Yun Kuang Xiaoming Sun State Key Laboratory of Chemical Resource Engineering College of ChemistryBeijing University of Chemical TechnologyBeijing 100029China Ocean Hydrogen Energy R&D Center Research Institute of Tsinghua University in ShenzhenShenzhen 518057China

Continuous seawater electrolysis is efficient for green hydrogen production,but some key issues have been *** example,the accumulated to saturated NaCl in electrolyte is poison to cathode by covering its surface and available active *** we demonstrate Pt/NiFe Prussian blue analogue(Pt/NiFePBA)electrode can continuously catalyze hydrogen evolution effectively at−500 mA·cm^(−2)in a 6 M NaOH electrolyte containing saturated NaCl,without being impeded by the formation of NaCl crystals on the electrode surface,which is in distinct contrast to commercial *** results indicate that Fe(CN)_(6)^(4−)spontaneously released by Pt/NiFePBA blocks the traditionally preferred basal plane growth of NaCl along{100}facets,but favors its growth along{110}basal *** alteration leads to an increased crystallization difficulty of NaCl near the electrode,rendering it halophobic(anti-NaCl precipitation)*** investigation should shed light on general salt involving process besides the practical implementation of seawater electrolysis.

关键词： seawater electrolysis saturate saline water hydrogen evolution reaction halophobic electrode Prussian blue analogue

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