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1
Yin, Ximing, Jin Chen, and Chuang Zhao. "Double Screen Innovation: Building Sustainable Core Competence through Knowledge Management." Sustainability 11, no. 16 (August 7, 2019): 4266. http://dx.doi.org/10.3390/su11164266.
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How to exploit the precipitated internal and external knowledge to build dynamic capability in the era of big data remains a big challenge for innovation and business sustainability. This paper documents a novel perspective to address this challenge by exploring the double screen innovation knowledge management practice in Commercial Aircraft Corporation of China Ltd. (COMAC). Drawing from the literature on knowledge management and knowledge-based view, this paper elaborates how the new type of knowledge management practice represented by the case of Double Screen Innovation (DSI) in COMAC could help enterprise build sustainable core competence, which provides new perspective for multi-level knowledge management towards business sustainability. DSI, as a novel way of knowledge management, optimizes the micro-level knowledge co-creation and sharing and macro-level organizational learning mechanisms to accelerate the knowledge accumulation and dissemination within the organization. The process of knowledge creation, transformation, and application helps to integrate and transform big data into useful business information, thus provides an endless driving force conducive to the establishment and promotion of the core competencies of enterprises.
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Wu, Guanghui. "A Trio of Commercial Aircraft Developments in China." Engineering 7, no. 4 (April 2021): 424–26. http://dx.doi.org/10.1016/j.eng.2020.07.033.
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Zhengfeng, Li. "Knowledge Integration in Collaborative New Product Development of Large Commercial Aircraft of China." International Journal of Materials, Mechanics and Manufacturing 2, no. 2 (May 2014): 169–73. http://dx.doi.org/10.7763/ijmmm.2014.v2.122.
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Wang, Yue, Dan Gao, and Jiangtao Si. "The design service life of wide-body commercial aircraft research based on airlines data." MATEC Web of Conferences 179 (2018): 03004. http://dx.doi.org/10.1051/matecconf/201817903004.
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To reasonably define the design service life of Chinese double aisles wide-body commercial aircraft, the exact market region and design condition are researched. The base market of Chinese double aisles wide-body commercial aircraft is China, Asia, Europe and the Pacific. In these zones, customers should be analyzed carefully, and the customers who are not available but play an important role in these zones should be picked off decisively. Besides, the flight length definition is also studied, which affects the design service life of aircraft obviously in small market region. After research, the results could reduce engineering difficulties, and also increase airlines adaptability and competitiveness in the specific market zone.
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Yu, Nu, Yao Zhang, Mengya Zhang, and Haifeng Li. "Thermal Condition and Air Quality Investigation in Commercial Airliner Cabins." Sustainability 13, no. 13 (June 23, 2021): 7047. http://dx.doi.org/10.3390/su13137047.
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Cabin air quality and thermal conditions have a direct impact on passenger and flight crew’s health and comfort. In this study, in-cabin thermal environment and particulate matter (PM) exposures were investigated in four China domestic flights. The mean and standard deviation of the in-cabin carbon dioxide (CO2) concentrations in two tested flights are 1440 ± 111 ppm. The measured maximum in-cabin carbon monoxide (CO) concentration is 1.2 ppm, which is under the US Occupational Safety and Health Administration (OSHA) permissible exposure limit of 10 ppm. The tested relative humidity ranges from 13.8% to 67.0% with an average of 31.7%. The cabin pressure change rates at the end of the climbing stages and the beginning of the descending stages are close to 10 hPa·min−1, which might induce the uncomfortable feeling of passengers and crew members. PM mass concentrations were measured on four flights. The results show that PM concentrations decreased after the aircraft cabin door closed and were affected by severe turbulences. The highest in-cabin PM concentrations were observed in the oldest aircraft with an age of 13.2 years, and the waiting phase in this aircraft generated the highest exposures.
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Li, Xiaoyong, Xiao Chai, and Hong Liu. "Conceptual design optimization of a wide-body commercial aircraft using a competitiveness model." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 234, no. 2 (July 23, 2019): 208–20. http://dx.doi.org/10.1177/0954410019862082.
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The conceptual design optimization of wide-body commercial aircraft is very challenging today. This paper deals with the conceptual design optimization problem of a next-cycle wide-body commercial aircraft, which has many similarities to the one being co-developed by China and Russia. The most difficult weaknesses are that the design requirements cannot be traded off during the conceptual design optimization process. To overcome this issue, a competitiveness model is built up for the wide-body commercial aircraft. The analytic hierarchy process is applied to formulate the competitiveness model, which is a multi-level evaluation model. The competiveness model includes three levels, i.e. target level, criteria level, and attributes level. The target level has an output, i.e. the competitiveness of the investigated aircraft, which serves as the single objective function in the conceptual design optimization problem. The criteria level includes four elements of economics, comfort, environmental impact, and adaptability. In addition, each criterion is further divided into more attributes, which are parameters obtained from the commercial aircraft conceptual design. By using the competitiveness model, the conceptual design optimization problem is converted into an unconstrained one that can be solved easily. Two optimizations with different judgment matrices for criteria level were performed. Compared with the baseline design candidate, the overall competitiveness of the optimal design for the optimization case 1 and case 2 increased by 9.28% and 11.51%, respectively, which benefits the designers and decision-makers.
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Bennett, James G., and Thomas Lamb. "Concurrent Engineering: Application and Implementation for U.S. Shipbuilding." Journal of Ship Production 12, no. 02 (May 1, 1996): 107–25. http://dx.doi.org/10.5957/jsp.1996.12.2.107.
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This paper reports on a SP-8 Panel project to analyze the application of Concurrent Engineering (CE) in U.S. shipbuilding and to perform a pilot implementation of CE within a U.S. shipyard. It describes (1) results of a Shipbuilding Concurrent Engineering Questionnaire survey; (2) a summary of product development performance benchmark surveys conducted at several U.S. shipyards; (3) visit to several foreign shipyards as well as Boeing Commercial Aircraft Company, Lockheed Missiles and Space Company, and the Concurrent Engineering Research Center to discuss implementation of CE; (4) requirements for successful CE implementation by U.S. shipbuilders; and (5) the status of the pilot CE implementation at Bath Iron Works Corporation.
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MacPherson, Alan. "The emergence of a new international competitor in the commercial aircraft sector: The China syndrome." Futures 41, no. 7 (September 2009): 482–89. http://dx.doi.org/10.1016/j.futures.2009.01.005.
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Soomro, H. A., E. Sulaiman, M. Jenal, M. F. Omar, L. I. Jusoh, and S. K. Rahimi. "Electromagnetic Flux Analysis of Ds Hesfm for Directly Driven Actuator Used in Aircraft Applications." International Journal of Engineering & Technology 7, no. 4.30 (November 30, 2018): 411. http://dx.doi.org/10.14419/ijet.v7i4.30.22347.
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This paper presents the electromagnetic flux analysis of dual stator hybrid excitation switched flux machines (DS HESFM) using segmental rotor for the directly driven electromechanical actuator aimed to use in aerospace applications. The advantage of designing a machine with directly driven system is to eliminate the intermediate gear box system with having minor component count and reduced jamming possibility. The proposed design of DS hybrid excitation with high torque density is investigated in this paper as a potential solution for aircraft applications. The key intentions of the design are high level of actuator integration to reduce the overall weight and volume and fault tolerance ability. The proposed design of DS HESFSM has simple structure, which consist of only six field excitation coils (FECs) housed in outer stator along with six armature coils (ACs) whereas, six permanent magnets (PMs) are positioned in the inner stator. Moreover, DS HESFM structure is analyzed at open circuit and short circuit conditions conditions by means of “commercial 2D FEA package, JMAG-designer ver. 14.0,” released by JSOL Corporation.
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Bowen, J. Ray, and David C. Rose. "On the Absence of Privately Owned, Publicly Traded Corporations in China: The Kirby Puzzle." Journal of Asian Studies 57, no. 2 (May 1998): 442–52. http://dx.doi.org/10.2307/2658832.
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In a recent article in this journal, William C. Kirby (1995) chronicled the development of China's Company Law, which was crafted in 1904 to promote industrial development by codifying a commercial code. Among other objectives, the Company Law was aimed at providing institutional support for the emergence of modern legal corporations. Indeed, it was a widespread belief among the Qing reformers of the period that “Modern industrial capitalism … demanded Western corporate structures to do business’ (Kirby 1995, 43). Kirby argued that after numerous revisions it has become clear that the Company Law has failed to promote the emergence of privately owned, publicly traded corporations. Given China's rich commercial tradition, its dramatic post-1978 reforms, and its rapid economic growth over the last two decades, Kirby's finding raises a most puzzling question for China scholars: Why is there not a single privately owned, publicly traded corporation (PPC) in mainland China?
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Boben, Mark, and Liu Yuheng. "OIL SPILL RESPONSE ORGANIZATION DEVELOPMENT—BOHAI SEA—CHINA." International Oil Spill Conference Proceedings 2005, no. 1 (May 1, 2005): 905–8. http://dx.doi.org/10.7901/2169-3358-2005-1-905.
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ABSTRACT Oil spill response along the coast of China has been recognized as an important issue by the Chinese government. The Bohai Sea in particular, is an area of high oil exploration and production activity, with offshore developments comprising platforms and FPSO's (floating, production, storage and off-loading) together with associated vessels and pipelines. Major shipping lanes from the East China Sea into China also pass through the offshore oil fields. For the oil companies operating in the area, the prospect of an accidental oil spill is a concern from both a domestic and international perspective. In 2000, the companies involved in upstream activities in the Bohai Sea began discussions with the China National Offshore Oil Corporation (CNOOC) to develop an oil spill response capability. Led by ConocoPhillips, the international oil companies worked with CNOOC to build a framework for developing an oil spill response organization (OSRO) to provide appropriate services within the Bohai Sea. The key tenet for this OSRO, was to be able to perform to international standards. In 2002, the CNOOC executive management, through its subsidiary, Bohai Corporation(COOBC) committed to establishing a commercial oil spill response organization, Bohai Environmental Services Ltd. (BES). The BES remit is focused on the Bohai Sea, but with the eventual goal of providing response services along the wider China coastal region and eventually fulfilling a longer term vision of expanding into the international market. This Paper describes the standards required by the international oil companies and how BES was conceived and organized to meet them.
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HE, JUAN. "WTO-plus commitments and emerging implications for China's large civil aircraft manufacturing." World Trade Review 13, no. 3 (December 16, 2013): 517–45. http://dx.doi.org/10.1017/s1474745613000268.
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AbstractChina's accession to the WTO in 2001 is widely accepted as a landmark event for the multilateral trade system and for the country. The large-scale WTO-plus commitments have nevertheless received unceasing criticism and discussion. This article is concerned with the resulting policy implications for the Chinese initiative to become a global producer of large civil aircraft at the next stage of development. A real-life case study is expected to provide robust evidence for inquiring whether China and emerging economies alike can smoothly advance up the global value chain while honouring their WTO obligations in good faith. The article confirms the widespread opinion that there are vast legal uncertainties ahead for China throughout this journey, and for that reason, a rigorous market-orientation effort is needed to strengthen its ability to compete in the commercial aviation sector.
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Tuladhar, Sandeep, Tri Ratna Bajracharya, and Shree Raj Shakya. "Evaluation and mitigation analysis of carbon footprint for an airline operator: Case of Nepal airlines corporation." Journal of Innovations in Engineering Education 4, no. 1 (March 5, 2021): 18–33. http://dx.doi.org/10.3126/jiee.v4i1.34817.
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This paper deals with evaluation and analysis of carbon footprint of an airline operator, Nepal Airlines Corporation (NAC) by using its actual flight and maintenance data from 2016 to 2019. NAC is a multi-fleet operator, of both turboprop and turbofan aircrafts. Carbon footprint in terms of Carbon Dioxide (CO2) emission has been calculated for NAC’s airline operations per individual aircraft, fleet-type and operating sector (i.e., international and domestic), and total ground handling operations. In each of the study years, contribution to NAC’s total CO2 production from its domestic fleet was found out to be very small (below 6% of yearly total), even though its fleet number outnumbered that of international fleet. This indicates better optimization opportunities for international-sector (turbofan) aircrafts than domestic-sector (turboprop) aircrafts. Reductions in fuel on-board as per prescribed levels, better airport slot management and selection of long-haul flight destinations have been identified as potential mitigation strategies for CO2 emission from international sector. Smaller aircrafts operating in domestic sectors are more prone to variations in occupancy rate and as such, NAC could focus on optimizing its commercial strategy to improve its CO2/passenger rate in domestic sector.
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McGuire, Steven. "Global value chains and state support in the aircraft industry." Business and Politics 16, no. 4 (December 2014): 615–39. http://dx.doi.org/10.1515/bap-2014-0014.
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The commercial aircraft industry is no stranger to trade friction, which has brought bitter international disputes over industrial policy to the World Trade Organization (WTO). Yet despite the fact that several countries, notably China, Japan and Russia have stated their intentions to develop aircraft that can compete with other countries, these efforts have not led to a trade dispute. What explains this pattern? Drawing on sources such as the Global Trade Alert database, this paper argues that that the complexity of the aircraft industry generates considerable barriers to entry. Moreover, emerging aerospace states have not repeated earlier efforts of direct subsidy, but rather, they have sought to position themselves in the global aerospace value chain, with selective government interventions designed to help national champions accumulate the necessary technical experience though collaboration with incumbent firms. However, the very diversity of government supports may make protectionist measures more difficult to identify.
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Beswick, K., D. Baumgardner, M. Gallagher, A. Volz-Thomas, P. Nedelec, K. Y. Wang, and S. Lance. "The backscatter cloud probe – a compact low-profile autonomous optical spectrometer." Atmospheric Measurement Techniques 7, no. 5 (May 23, 2014): 1443–57. http://dx.doi.org/10.5194/amt-7-1443-2014.
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Abstract. A compact (500 cm3), lightweight (500 g), near-field, single particle backscattering optical spectrometer is described that mounts flush with the skin of an aircraft and measures the concentration and optical equivalent diameter of particles from 5 to 75 μm. The backscatter cloud probe (BCP) was designed as a real-time qualitative cloud detector primarily for data quality control of trace gas instruments developed for the climate monitoring instrument packages that are being installed on commercial passenger aircraft as part of the European Union In-Service Aircraft for a Global Observing System (IAGOS) program (http://www.iagos.org/). Subsequent evaluations of the BCP measurements on a number of research aircraft, however, have revealed it capable of delivering quantitative particle data products including size distributions, liquid-water content and other information on cloud properties. We demonstrate the instrument's capability for delivering useful long-term climatological, as well as aviation performance information, across a wide range of environmental conditions. The BCP has been evaluated by comparing its measurements with those from other cloud particle spectrometers on research aircraft and several BCPs are currently flying on commercial A340/A330 Airbus passenger airliners. The design and calibration of the BCP is described in this article, along with an evaluation of measurements made on the research and commercial aircraft. Preliminary results from more than 7000 h of airborne measurements by the BCP on two Airbus A340s operating on routine global traffic routes (one Lufthansa, the other China Airlines) show that more than 340 h of cloud data have been recorded at normal cruise altitudes (> 10 km) and more than 40% of the > 1200 flights were through clouds at some point between takeoff and landing. These data are a valuable contribution to databases of cloud properties, including sub-visible cirrus, in the upper troposphere and useful for validating satellite retrievals of cloud water and effective radius; in addition, providing a broader, geographically and climatologically relevant view of cloud microphysical variability that is useful for improving parameterizations of clouds in climate models. Moreover, they are also useful for monitoring the vertical climatology of clouds over airports, especially those over megacities where pollution emissions may be impacting local and regional climate.
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Mei, Biao, Weidong Zhu, and Yinglin Ke. "Positioning variation analysis and control for automated drilling in aircraft manufacturing." Assembly Automation 38, no. 4 (September 3, 2018): 412–19. http://dx.doi.org/10.1108/aa-01-2018-009.
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Purpose Aircraft assembly demands high position accuracy of drilled fastener holes. Automated drilling is a key technology to fulfill the requirement. The purpose of the paper is to conduct positioning variation analysis and control for an automated drilling to achieve a high positioning accuracy. Design/methodology/approach The nominal and varied connective models of automated drilling are constructed for positioning variation analysis regarding automated drilling. The principle of a strategy for reducing positioning variation in drilling, which shortens the positioning variation chain with the aid of an industrial camera-based vision system, is explored. Moreover, other strategies for positioning variation control are developed based on mathematical analysis to further reduce the position errors of the drilled fastener holes. Findings The propagation and accumulation of an automated drilling system’s positioning variation are explored. The principle of reducing positioning variation in an automated drilling using a monocular vision system is discussed from the view of variation chain. Practical implications The strategies for reducing positioning variation, rooted in the constructed positioning variation models, have been applied to a machine-tool based automated drilling system. The system is developed for a wing assembly of an aircraft in the Aviation Industry Corporation of China. Originality/value Propagation, accumulation and control of positioning variation in an automated drilling are comprehensively explored. Based on this, the positioning accuracy in an automated drilling is controlled below 0.13 mm, which can meet the requirement for the assembly of the aircraft.
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Ren, Jianlin, Junjie Liu, Xiaodong Cao, Fei Li, and Jianmin Li. "Ultrafine particles in the cabin of a waiting commercial airliner at Tianjin International Airport, China." Indoor and Built Environment 27, no. 9 (June 9, 2017): 1247–58. http://dx.doi.org/10.1177/1420326x17713257.
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Passengers and crew on board of commercial airliners often spend extra time in the cabin waiting for departure due to flight delays. During the waiting period, a large amount of ambient ultrafine particles (UFPs) may penetrate into the aircraft cabin through the environmental control system (ECS) and ground air-conditioning cart (GAC). However, limited data are available for human exposure, in waiting commercial airliners, to freshly emitted UFPs from the exhaust of ground vehicles and airliners. To address this issue, we measured the ambient and in-cabin particle number concentrations and particle size distributions (PSDs) simultaneously in an MD-82 airliner parked at Tianjin International Airport, China. When air was supplied to the cabin by GAC, particle counts variation outdoors caused in-cabin variation with a 1–2 min delay. The in-cabin and ambient PSDs ranged from 15 to 600 nm were bimodal, with peaks at 30–40 and 70–90 nm. The GAC and ECS removed 1–73% particles in the size range of 15–100 nm and 30–47% in the size range of 100–600 nm. The relationship between the penetration factor and particle size was an inverted U-curve. An improved particle dynamic model from this study was used to calculate the time-dependent in-cabin UFPs concentrations with dramatic changes in outdoor concentration.
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Beswick, K., D. Baumgardner, M. Gallagher, and R. Newton. "The Backscatter Cloud Probe – a compact low-profile autonomous optical spectrometer." Atmospheric Measurement Techniques Discussions 6, no. 4 (August 16, 2013): 7379–424. http://dx.doi.org/10.5194/amtd-6-7379-2013.
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Abstract. A compact (500 cm3), lightweight (500 g), near-field, single particle backscattering optical spectrometer is described that mounts flush with the skin of an aircraft and measures the concentration and optical equivalent diameter of particles from 5 to 75 μm. The Backscatter Cloud Probe (BCP) was designed as a real-time qualitative cloud detector primarily for data quality control of trace gas instruments developed for the climate monitoring instrument packages that are being installed on commercial passenger aircraft as part of the European Union In-Service Aircraft for a Global Observing System (IAGOS) program (http://www.iagos.org/). Subsequent evaluations of the BCP measurements on a number of research aircraft, however, have revealed it capable of delivering quantitative particle data products including size distributions, liquid water content and other information on cloud properties. We demonstrate the instrument's capability for delivering useful long-term climatological information, across a wide range of environmental conditions. The BCP has been evaluated by comparing its measurements with those from other cloud particle spectrometers on research aircraft and several BCPs are currently flying on commercial A340/A330 Airbus passenger airliners. The design and calibration of the BCP is described in this presentation, along with an evaluation of measurements made on the research and commercial aircraft. Comparisons of the BCP with two other cloud spectrometers, the Cloud Droplet Probe (CDP) and the Cloud and Aerosol Spectrometer (CAS), show that the BCP size distributions agree well with those from the other two, given the intrinsic limitations and uncertainties related to the three instruments. Preliminary results from more than 7000 h of airborne measurements by the BCP on two Airbus A-340s operating on routine global traffic routes (one Lufthansa, the other China Airlines) show that more than 340 h of cloud data have been recorded at normal cruise altitudes (> 10 km) and more than 40% of the > 1200 flights were through clouds at some point between takeoff and landing. These data are a valuable contribution to data bases of cloud properties, including sub-visible cirrus, in the upper troposphere and useful for validating satellite retrievals of cloud water and effective radius as well as providing a broader, geographically and climatologically relevant view of cloud microphysical variability useful for improving parameterizations of clouds in climate models. They are also useful for monitoring the vertical climatology of clouds over airports, especially those over mega-cities where pollution emissions may be impacting local and regional climate.
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Li, Han, Nasidan Wang, Xuefei Han, Haoran Yuan, and Jiang Xie. "Mechanism Identification and Kinetics Analysis of Thermal Degradation for Carbon Fiber/Epoxy Resin." Polymers 13, no. 4 (February 14, 2021): 569. http://dx.doi.org/10.3390/polym13040569.
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For carbon fiber epoxy resin used in aerostructure, thermal degradation mechanism and kinetics play an important role in the evaluation of thermal response and combustion characteristics. However, the thermal decomposition process and mechanism are difficult to unify strictly due to the complexity of the components from different suppliers. In the present study, a product of carbon fiber epoxy resin made by AVIC (Aviation Industry Corporation of China) composite corporation is examined to identify its thermal degradation mechanism and pyrolysis products by measurements, including simultaneous thermal analysis, Fourier transform infrared spectroscopy and mass spectrometry, establish the kinetic model by Kissinger/Friedman/Ozawa/Coats-Redfern methods. The results show thermal degradation occurs in three steps under the inert atmosphere, but in four steps under air atmosphere, respectively. The first two steps in both environments are almost the same, including drying, carbon dioxide escape and decomposition of the epoxy resin. In the third step of inert atmosphere, phenol is formed, methane decreases, carbon monoxide basically disappears and carbon dioxide production increases. However, in air, thermal oxidation of the carbonaceous residues and intermolecular carbonization are observed. Furthermore, thermal degradation reaction mechanism submits to the F4 model. These results provide fundamental and comprehensive support for the application of carbon fiber epoxy resin in aircraft industry.
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So, Billy K. L., and Sufumi So. "Entrepreneurship in the textbook business in modern East Asia: Kinkōdō of Meiji Japan and the Commercial Press of early twentieth-century China." Bulletin of the School of Oriental and African Studies 80, no. 3 (August 31, 2017): 547–69. http://dx.doi.org/10.1017/s0041977x17000933.
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AbstractThis article compares the ways in which two major textbook publishers in East Asia – namely Kinkōdō in Meiji Japan and the Commercial Press in early twentieth-century China – practised the Western model of corporations to build a new kind of publishing business in their respective societies, which were undergoing significant transformation. The study suggests that, although the use of the model could imply global business convergence, its transplantation process was largely shaped by entrepreneurs who negotiated the Western model as an alternative newly opened to them and brought to light variant forms of practice tailored to serve their own aspirations in corporate directions such as industrial integration and ownership structure. The two cases present two distinct patterns of developing a new textbook publishing business under the same corporation model.
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Mei, Biao, Weidong Zhu, Huiyue Dong, and Yinglin Ke. "Coordination error control for accurate positioning in movable robotic drilling." Assembly Automation 35, no. 4 (September 7, 2015): 329–40. http://dx.doi.org/10.1108/aa-04-2015-024.
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Purpose – This paper aims to propose a roadmap to control the robot–subassembly (R–S) coordination errors in movable robotic drilling. Fastener hole drilling for multi-station aircraft assembly demands a robotic drilling system with expanded working volume and high positioning accuracy. However, coordination errors often exist between the robot and the subassembly to be drilled because of disturbances. Design/methodology/approach – Mechanical pre-locating and vision-based robot base frame calibration are consecutively implemented to achieve in-process robot relocation after station transfer. Thus, coordination errors induced by robotic platform movements, inconsistent thermal effects, etc. are eliminated. The two-dimensional (2D) vision system is applied to measure the remainder of the R–S coordination errors, which is used to enhance the positioning accuracy of the robot. Accurate estimation of measured positioning errors is of great significance for evaluating the positioning accuracy. For well estimation of the positioning errors with small samples, a bootstrap approach is put forward. Findings – A roadmap for R–S coordination error control using a 2D vision system, composed of in-process relocation, coordination error measurement and drilled position correction, is developed for the movable robotic drilling. Practical implications – The proposed roadmap has been integrated into a drilling system for the assembly of flight control surfaces of a transport aircraft in Aviation Industry Corporation of China. The position accuracy of the drilled fastener holes is well ensured. Originality/value – A complete roadmap for controlling coordination errors and improving positioning accuracy is proposed, which makes the high accuracy and efficiency available in movable robotic drilling for aircraft manufacturing.
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Li, J., T. Sreenuch, and A. Tsourdos. "Condition Based Maintenance Optimization of an Aircraft Assembly Process Considering Multiple Objectives." ISRN Aerospace Engineering 2014 (February 11, 2014): 1–13. http://dx.doi.org/10.1155/2014/204546.
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The Commercial Aircraft Cooperation of China (COMAC) ARJ21 fuselage’s final assembly process is used as a case study. The focus of this paper is on the condition based maintenance regime for the (semi-) automatic assembly machines and how they impact the throughput of the fuselage assembly process. The fuselage assembly process is modeled and analyzed by using agent based simulation in this paper. The agent approach allows complex process interactions of assembly, equipment, and maintenance to be captured and empirically studied. In this paper, the built network is modeled as the sequence of activities in each stage, which are parameterized by activity lead time and equipment used. A scatter search is used to find multiobjective optimal solutions for the CBM regime, where the maintenance related cost and production rate are the optimization objectives. In this paper, in order to ease computation intensity caused by running multiple simulations during the optimization and to simplify a multiobjective formulation, multiple Min-Max weightings are used to trace Pareto front. The empirical analysis reviews the trade-offs between the production rate and maintenance cost and how sensitive the design solution is to the uncertainties.
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Jiang, Junxia, Shenglin Zhang, and Yuxiao He. "Wheel design and motion analysis of a new heavy-duty AGV in aircraft assembly lines." Assembly Automation 40, no. 3 (December 16, 2019): 387–97. http://dx.doi.org/10.1108/aa-01-2019-0009.
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Purpose The flexible automatic transportation and manual assembly jobs for large aircraft components demand an automated guided vehicle (AGV) system with heavy-duty capacity and omnidirectional movability. This paper aims to propose a four driving-steering wheels-four supporting-steering wheels (4DSW-4SSW) layout plan to enhance the controllability and moving stability of AGV. Design/methodology/approach The anti-vibration structure of DS wheels and high-torque steering mechanism of SS wheels with tapered rolling bearings are rigorously designed to meet the functional requirements. Based on the specific wheel layout and vehicle dynamics, the rotational kinematic model as well as the straight and rotational dynamic models of AGV are established by the authors. To well verify the motion characteristics of wheels under heavy load in three motion states including straight motion, self-rotation and rotation around a certain point, the simulations in ADAMS and factory experiments have all been conducted. Findings Simulation results indicate that normal and friction forces of DS wheels and SS wheels are very stable except for some small oscillations, which are caused by non-center load distribution on AGV. Experimental results on driving speed of AGV have directly demonstrated that its positioning accuracy is enough for use in real aircraft assembly lines. Practical implications The designed AGV system has been applied to the final assembly line of a certain aircraft in Aviation Industry Corporation of China, Ltd, whose assembly efficiency and flexibility have been significantly improved. Originality/value A new layout plan of wheels for an omnidirectional heavy-duty AGV is proposed, which enhances the operating and moving capacity of AGV. A function of human-machine collaboration is also offered by the AGV for transporting large workpieces intelligently and economically in aerospace and other heavy industries.
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Roux, Frank, Hannah Clark, Kuo-Ying Wang, Susanne Rohs, Bastien Sauvage, and Philippe Nédélec. "The influence of typhoons on atmospheric composition deduced from IAGOS measurements over Taipei." Atmospheric Chemistry and Physics 20, no. 6 (April 2, 2020): 3945–63. http://dx.doi.org/10.5194/acp-20-3945-2020.
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Abstract. The research infrastructure IAGOS (In-Service Aircraft for a Global Observing System) equips commercial aircraft with instruments to monitor the composition of the atmosphere during flights around the world. In this article, we use data from two China Airlines aircraft based in Taipei (Taiwan) which provided daily measurements of ozone, carbon monoxide and water vapour throughout the summer of 2016. We present time series, from the surface to the upper troposphere, of ozone, carbon monoxide and relative humidity near Taipei, focusing on periods influenced by the passage of typhoons. We examine landing and take-off profiles in the vicinity of tropical cyclones using ERA-5 reanalyses to elucidate the origin of the anomalies in the vertical distribution of these chemical species. Results indicate a high ozone content in the upper- to middle-troposphere track of the storms. The high ozone mixing ratios are generally correlated with potential vorticity and anti-correlated with relative humidity, suggesting stratospheric origin. These results suggest that tropical cyclones participate in transporting air from the stratosphere to troposphere and that such transport could be a regular feature of typhoons. After the typhoons passed Taiwan, the tropospheric column was filled with substantially lower ozone mixing ratios due to the rapid uplift of marine boundary layer air. At the same time, the relative humidity increased, and carbon monoxide mixing ratios fell. Locally, therefore, the passage of typhoons has a positive effect on air quality at the surface, cleansing the atmosphere and reducing the mixing ratios of pollutants such as CO and O3.
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Lin, Wei-Ting, Wen-Que Zhao, Yi-Hua Chang, Jiann-Shi Yang, and An Cheng. "The Effect of Incorporating Ultra-Fine Spherical Particles on Rheology and Engineering Properties of Commercial Ultra-High-Performance Grout." Crystals 11, no. 9 (August 29, 2021): 1040. http://dx.doi.org/10.3390/cryst11091040.
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In this study, ultra-fine spherical particles of silica fume and reactive ultra-fine fly ash were added to a mixture of commercial ultra-high-performance grout (UHPG) with the aim of enhancing the rheological properties, compressive strength, compactness, and permeability. This commercial UHPG study was conducted in collaboration with Triaxis Corporation (Changsha city, Hunan province, China). A water-to-binder ratio of 0.21 and a binder-to-fine aggregates ratio of 1.17 were used as fixed parameters, and the binders were a combination of type-II Portland cement, sulphoaluminate cement, silica fume, and reactive ultra-fine fly ash (RUFA). Polycarboxylate superplasticizer powder was used to control the rheology. The results revealed excellent compressive strength, volume stability, and resistance to chloride penetration. Mercury intrusion porosimetry and scanning electron microscopy tests revealed that the medium-sized RUFA particles with small silica fume particles completely filled the spaces between large cement particles to achieve optimal densification. This mixture also produced dense hydration and calcium-silicate-hydrates colloids, which filled the microstructures of the UHPG resulting in excellent engineering properties and durability. This commercially available UHPG mix responded to excellent compressive strengths approaching 120 MPa and exhibited good workability with a loss of slump-flow rate up to 33% after 60 min. It also exhibited very low abrasion resistance (0.5%), stable shrinkage and expansion rates (stabilization over 10 days), very low chloride diffusion coefficient (less than 0.1 × 10−14 m2/s) with a denser microstructure. This commercial UHPG (UHPG-120) has been developed to meet the needs of the market.
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Hardus, Sarah. "Chinese National Oil Companies in Ghana: The Cases of cnooc and Sinopec." Perspectives on Global Development and Technology 13, no. 5-6 (October 8, 2014): 588–612. http://dx.doi.org/10.1163/15691497-12341319.
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This article uses the case of Ghana to provide insight into the policies and strategies used by, as well as the cooperation between, Chinese state actors in their quest for natural resources in Africa. In 2007, Ghana discovered commercial quantities of oil. While the so-called Jubilee oilfield was initially divided amongst primarily Western oil companies, in 2010 the China National Offshore Oil Corporation partnered with Ghana’s national oil company to try and purchase a stake in Jubilee. Although this bid was rejected, later that year a second Chinese state-owned oil company, Sinopec, was able to access Ghana’s oil indirectly through an offtaker agreement, linked to a $3 billion dollar loan provided by the state-owned China Development Bank. The article uses these two cases to examine the level of coordination between the strategies of Chinese state actors in their attempts to access African natural resources. It shows that China’s national oil companies and policy banks operate in increasingly autonomous ways. This goes against the developmental state thesis, which argues that the Chinese state has full control over the overseas activities of its state actors. The article also shows that national political institutions in Africa can make use of and are able to influence Chinese resource deals, countering the notion of African passivity.
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Ihara, Yukitoshi, Koichiro Takubo, Tatsuo Nakai, and Ryuta Sato. "Effect of CAD/CAM Post Process on S-Shaped Machining Test for Five-Axis Machining Center." International Journal of Automation Technology 13, no. 5 (September 5, 2019): 593–601. http://dx.doi.org/10.20965/ijat.2019.p0593.
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ISO 10791-7, the test standard for machining centers, was revised in 2014 to add the test method for five-axis machining centers. However, an S-shaped test was additionally proposed as an accuracy test of aircraft parts from China immediately before the establishment of the test standard. In an ISO meeting, various problems such as creating three-dimensional models and evaluation items have been indicated for the proposed test method. By revising these problems, the standard was finally completed and will be introduced as an informative annex soon. However, it is still an inappropriate test method from the viewpoint of performance inspection for machine tools. In this research, the S-shaped test method draft proposed in September 2016 is tested using two types of five-axis machining centers and commercial CAM software. Consequently, a hidden problem is revealed, that is, an abrupt movement that affected the final result is added to the machine because the rotation direction of the rotary axes is not ideal. This is attributed to the performance of the CAM software’s post processor that converts from CL data to NC program. This study provides some insights into avoiding the problem and obtaining better test results.
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Lee, Dan-Bi, and Hye-Yeong Chun. "A Numerical Study of Aviation Turbulence Encountered on 13 February 2013 over the Yellow Sea between China and the Korean Peninsula." Journal of Applied Meteorology and Climatology 57, no. 4 (April 2018): 1043–60. http://dx.doi.org/10.1175/jamc-d-17-0247.1.
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AbstractAt 0247 UTC 13 February 2013, a South Korean commercial aircraft encountered moderate-level clear-air turbulence at ~24 000 ft (~7.3 km) over the Yellow Sea (121.25°E, 38.55°N) en route from Incheon, South Korea, to Tianjin, China. Two crew members were severely injured by this event. To investigate the possible mechanisms of this event, a high-resolution numerical simulation using the Weather Research and Forecasting Model was conducted. In the synoptic-scale flow pattern, one of two bifurcated jet streams passed over the Yellow Sea, and strong horizontal and vertical gradients of the wind occurred on the northern edge of the jet stream near the flight route. An upper-level frontal system on the cyclonic shear side of the jet intensified as it moved northward toward a strengthening upper-level trough in northeastern China. The developed jet–frontal system induced strong vertical wind shear and tropopause folding, which extended down to about z = 5 km, near the observed turbulence region. Despite a relatively high stability with an intrusion of stratospheric air with tropopause folding, the strong vertical wind shear led to a small Richardson number in the incident region, which in turn induced the aviation turbulence through the Kelvin–Helmholtz instability. Although small-scale mountain waves were evident during the passage of flight before the incident time, breaking of these waves was not likely the key factor for the observed turbulence, given that the wave amplitudes were weak and that the strong zonal wind on the upstream of the mountain waves prohibited wave saturation and breakdown.
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LI, Hong. "Depoliticization and Regulation of Sovereign Wealth Funds: A Chinese Perspective." Asian Journal of International Law 1, no. 2 (October 25, 2010): 403–22. http://dx.doi.org/10.1017/s204425131000010x.
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AbstractThe China Investment Corporation (CIC) has often been perceived as a threat by Western economies. Such fears, however, are unfounded as the severe losses incurred by CIC during the recent economic crisis reveals that the fund, just like other investment entities, is vulnerable to market conditions. Moreover, given their relative lack of expertise in international investment, the regulation and development of “young and inexperienced” sovereign wealth funds (SWFs) within their home state is more pertinent than the defensive regulation structured by the host states in which SWFs invest. Positive financial returns should always be the fundamental goal of SWFs, rather than non-commercial considerations. This article proposes a three-step approach to regulating SWFs from a Chinese perspective: (1) home states should distinguish between their roles as shareholders and managers of state-owned capital-exporting institutions, and can use the Santiago Principles for that purpose; (2) host countries should not discriminate against SWFs but treat them as private institutional investors; and (3) there should be a clarification of the international investment regime regarding state investment. If these three steps are taken, SWFs would be depoliticized, and biased regulatory agencies and regulations would be a thing of the past. Under a broad regime, concerns between home and host states could then be addressed at bilateral or multilateral forums.
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Tang, Wenbo, Pak Wai Chan, and George Haller. "Lagrangian Coherent Structure Analysis of Terminal Winds Detected by Lidar. Part I: Turbulence Structures." Journal of Applied Meteorology and Climatology 50, no. 2 (February 1, 2011): 325–38. http://dx.doi.org/10.1175/2010jamc2508.1.
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Abstract The accurate real-time detection of turbulent airflow patterns near airports is important for safety and comfort in commercial aviation. In this paper, a method is developed to identify Lagrangian coherent structures (LCS) from horizontal lidar scans at Hong Kong International Airport (HKIA) in China. LCS are distinguished frame-independent material structures that create localized attraction, repulsion, or high shear of nearby trajectories in the flow. As such, they are the fundamental structures behind airflow patterns such as updrafts, downdrafts, and wind shear. Based on a recently developed finite-domain–finite-time Lyapunov exponent (FDFTLE) algorithm from Tang et al. and on new Lagrangian diagnostics presented in this paper that are pertinent to the extracted FDFTLE ridges, the authors differentiate LCS extracted from lidar data. It is found that these LCS derived from horizontal lidar scans compare well to convergence and divergence suggested by vertical slice scans. At HKIA, horizontal scans are predominant: they cover much bigger azimuthal ranges as compared with only two azimuthal angles from the vertical scans. LCS extracted from horizontal scans are thus advantageous in providing organizing turbulence structures over the entire observational domain as compared with a single line along the vertical scan direction. In Part II of this study, the authors will analyze the evolution of LCS and their impacts on landing aircraft based on recorded flight data.
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Lin, Shunjiang, Guansheng Fan, Yuan Lu, Mingbo Liu, Yi Lu, and Qifeng Li. "A Mixed-Integer Convex Programming Algorithm for Security-Constrained Unit Commitment of Power System with 110-kV Network and Pumped-Storage Hydro Units." Energies 12, no. 19 (September 24, 2019): 3646. http://dx.doi.org/10.3390/en12193646.
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The secure operation of 110-kV networks should be considered in the optimal generation dispatch of regional power grids in large central cities. However, since 110-kV lines do not satisfy the premise of R << X in the direct current power flow (DCPF) model, the DCPF, which is mostly applied in the security-constrained unit commitment (SCUC) problem of high-voltage power grids, is no longer suitable for describing the active power flow of regional power grids in large central cities. Hence, the quadratic active power flow (QAPF) model considering the resistance of lines is proposed to describe the network security constraints, and an SCUC model for power system with 110-kV network and pumped-storage hydro (PSH) units is established. The analytical expressions of the spinning reserve (SR) capacity of PSH units are given considering different operational modes, and the SR capacity of PSH units is included in the constraint of the SR capacity requirement of the system. The QAPF is a set of quadratic equality constraints, making the SCUC model a mixed-integer nonlinear non-convex programming (MINNP) model. To reduce the computational complexity of solving the model when applied in actual large-scale regional networks, the QAPF model is relaxed by its convex hull, and the SCUC model is transformed into a mixed-integer convex programming (MICP) model, which can be solved to obtain the global optimal solution efficiently and reliably by the mature commercial solver GUROBI (24.3.3, GAMS Development Corporation, Guangzhou, China). Test results on the IEEE-9 bus system, the PEGASE 89 bus system and the Shenzhen city power grid including the 110-kV network demonstrate that the relaxed QAPF model has good calculation accuracy and efficiency, and it is suitable for solving the SCUC problem in large-scale regional networks.
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Johnson, Raymond L., Lan Nguyen, and Terry Russell. "Next steps to crack the code on tight Permian Toolachee and Patchawarra sandstones of the Cooper Basin, southwest Queensland." APPEA Journal 56, no. 2 (2016): 533. http://dx.doi.org/10.1071/aj15039.
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Historic wells drilled by Real Energy Corporation Limited (Real Energy) in the Windorah Trough (Cooper Basin, southwest Queensland) characterised the Toolachee and Patchawarra formations as being gas-charged, tight-gas, sandstone/lacustrine shale sequences having layers of coaly source rock with high total organic content and moderate hydrocarbon indices. Consistent with being tight-gas reservoirs, drill stem tests have mostly either failed to produce gas or resulted in non-commercial flow rates. To date, North American methodologies for tight and shale gas extraction have not been consistently successful when applied in non-normal stress regimes outside of North America (i.e. Cooper Basin, China, Poland, Middle East, etc). Real Energy anticipated that North American technologies and practices were not likely to be directly applicable, as noted by published case studies for Australian shale gas wells (Johnson and Greenstreet, 2003; Pitkin et al, 2012; Scott et al, 2013; Johnson et al, 2015). Thus, it became an imperative to evaluate any methodologies or technologies more applicable for the Australian strike-slip to transpressional stress regimes to prevent fracture misalignment or disorientation, effects that result in ineffective fracture stimulation. Overall, a more scientific approach must be applied to developing and understanding the most efficient reservoir stimulation processes (e.g. drilling techniques, rock mechanical properties determination, well azimuth, perforating schema, and well interval selection) to optimise the stimulated reservoir volume (SRV). In this extended abstract the authors take the first steps at defining the stimulation strategies required for these tight sandstones using data and results from two case study wells. The authors outline the well observations and report key lessons in a cooperative spirit to solicit industry feedback and further technologies that can aid development of fit-for-purpose technologies to facilitate extraction of these largely untapped resources across the undeveloped troughs and flanks of the Cooper Basin.
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Osman, Mohammed K., David W. Tarasick, Jane Liu, Omid Moeini, Valerie Thouret, Vitali E. Fioletov, Mark Parrington, and Philippe Nédélec. "Carbon monoxide climatology derived from the trajectory mapping of global MOZAIC-IAGOS data." Atmospheric Chemistry and Physics 16, no. 15 (August 12, 2016): 10263–82. http://dx.doi.org/10.5194/acp-16-10263-2016.
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Abstract. A three-dimensional gridded climatology of carbon monoxide (CO) has been developed by trajectory mapping of global MOZAIC-IAGOS in situ measurements from commercial aircraft data. CO measurements made during aircraft ascent and descent, comprising nearly 41 200 profiles at 148 airports worldwide from December 2001 to December 2012, are used. Forward and backward trajectories are calculated from meteorological reanalysis data in order to map the CO measurements to other locations and so to fill in the spatial domain. This domain-filling technique employs 15 800 000 calculated trajectories to map otherwise sparse MOZAIC-IAGOS data into a quasi-global field. The resulting trajectory-mapped CO data set is archived monthly from 2001 to 2012 on a grid of 5° longitude × 5° latitude × 1 km altitude, from the surface to 14 km altitude.The mapping product has been carefully evaluated, firstly by comparing maps constructed using only forward trajectories and using only backward trajectories. The two methods show similar global CO distribution patterns. The magnitude of their differences is most commonly 10 % or less and found to be less than 30 % for almost all cases. Secondly, the method has been validated by comparing profiles for individual airports with those produced by the mapping method when data from that site are excluded. While there are larger differences below 2 km, the two methods agree very well between 2 and 10 km with the magnitude of biases within 20 %. Finally, the mapping product is compared with global MOZAIC-IAGOS cruise-level data, which were not included in the trajectory-mapped data set, and with independent data from the NOAA aircraft flask sampling program. The trajectory-mapped MOZAIC-IAGOS CO values show generally good agreement with both independent data sets.Maps are also compared with version 6 data from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. Both data sets clearly show major regional CO sources such as biomass burning in Central and southern Africa and anthropogenic emissions in eastern China. While the maps show similar features and patterns, and relative biases are small in the lowermost troposphere, we find differences of ∼ 20 % in CO volume mixing ratios between 500 and 300 hPa. These upper-tropospheric biases are not related to the mapping procedure, as almost identical differences are found with the original in situ MOZAIC-IAGOS data. The total CO trajectory-mapped MOZAIC-IAGOS column is also higher than the MOPITT CO total column by 12–16 %.The data set shows the seasonal CO cycle over different latitude bands and altitude ranges as well as long-term trends over different latitude bands. We observe a decline in CO over the northern hemispheric extratropics and the tropics consistent with that reported by previous studies using other data sources.We anticipate use of the trajectory-mapped MOZAIC-IAGOS CO data set as an a priori climatology for satellite retrieval and for air quality model validation and initialization.
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Osman, M., D. W. Tarasick, J. Liu, O. Moeini, V. Thouret, V. E. Fioletov, M. Parrington, and P. Nédélec. "Carbon monoxide climatology derived from the trajectory mapping of global MOZAIC-IAGOS data." Atmospheric Chemistry and Physics Discussions 15, no. 21 (November 2, 2015): 29871–937. http://dx.doi.org/10.5194/acpd-15-29871-2015.
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Abstract. A three-dimensional gridded climatology of carbon monoxide (CO) has been developed by trajectory mapping of global MOZAIC-IAGOS in situ measurements from commercial aircraft data. CO measurements made during aircraft ascent and descent, comprising nearly 41 200 profiles at 148 airports worldwide from December 2001 to December 2012 are used. Forward and backward trajectories are calculated from meteorological reanalysis data in order to map the CO measurements to other locations, and so to fill in the spatial domain. This domain-filling technique employs 15 800 000 calculated trajectories to map otherwise sparse MOZAIC-IAGOS data into a quasi-global field. The resulting trajectory-mapped CO dataset is archived monthly from 2001–2012 on a grid of 5° longitude × 5° latitude × 1 km altitude, from the surface to 14 km altitude. The mapping product has been carefully evaluated, by comparing maps constructed using only forward trajectories and using only backward trajectories. The two methods show similar global CO distribution patterns. The magnitude of their differences is most commonly 10 % or less, and found to be less than 30 % for almost all cases. The trajectory-mapped CO dataset has also been validated by comparison profiles for individual airports with those produced by the mapping method when data from that site are excluded. While there are larger differences below 2 km, the two methods agree very well between 2 and 10 km with the magnitude of biases within 20 %. Maps are also compared with Version 6 data from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. While agreement is good in the lowermost troposphere, the MOPITT CO profile shows negative biases of ~ 20 % between 500 and 300 hPa. These upper troposphere biases are not related to the mapping procedure, as almost identical differences are found with the original in situ MOZAIC-IAGOS data. The total CO trajectory-mapped MOZAIC-IAGOS climatology column agrees with the MOPITT CO total column within ±5 %, which is consistent with previous reports. The maps clearly show major regional CO sources such as biomass burning in the central and southern Africa and anthropogenic emissions in eastern China. The dataset shows the seasonal CO cycle over different latitude bands and altitude ranges that are representative of the regions as well as long-term trends over latitude bands. We observe a decline in CO over the Northern Hemisphere extratropics and the tropics consistent with that reported by previous studies. Similar maps have been made using the concurrent O3 measurements by MOZAIC-IAGOS, as the global variation of O3–CO correlations can be a useful tool for the evaluation of ozone sources and transport in chemical transport models. We anticipate use of the trajectory-mapped MOZAIC-IAGOS CO dataset as an a priori climatology for satellite retrieval, and for air quality model validation and initialization.
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Chang, Kai-Lan, Owen R. Cooper, Audrey Gaudel, Irina Petropavlovskikh, and Valérie Thouret. "Statistical regularization for trend detection: an integrated approach for detecting long-term trends from sparse tropospheric ozone profiles." Atmospheric Chemistry and Physics 20, no. 16 (August 26, 2020): 9915–38. http://dx.doi.org/10.5194/acp-20-9915-2020.
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Abstract. Detecting a tropospheric ozone trend from sparsely sampled ozonesonde profiles (typically once per week) is challenging due to the short-lived anomalies in the time series resulting from ozone's high temporal variability. To enhance trend detection, we have developed a sophisticated statistical approach that utilizes a geoadditive model to assess ozone variability across a time series of vertical profiles. Treating the profile time series as a set of individual time series on discrete pressure surfaces, a class of smoothing spline ANOVA (analysis of variance) models is used for the purpose of jointly modeling multiple correlated time series (on separate pressure surfaces) by their associated seasonal and interannual variabilities. This integrated fit method filters out the unstructured variation through a statistical regularization (i.e., a roughness penalty) by taking advantage of the additional correlated data points available on the pressure surfaces above and below the surface of interest. We have applied this technique to the trend analysis of the vertically correlated time series of tropospheric ozone observations from (1) IAGOS (In-service Aircraft for a Global Observing System) commercial aircraft profiles above Europe and China throughout 1994–2017 and (2) NOAA GML's (Global Monitoring Laboratory) ozonesonde records at Hilo, Hawaii, (1982–2018) and Trinidad Head, California (1998–2018). We illustrate the ability of this technique to detect a consistent trend estimate and its effectiveness in reducing the associated uncertainty in the profile data due to the low sampling frequency. We also conducted a sensitivity analysis of frequent IAGOS profiles above Europe (approximately 120 profiles per month) to determine how many profiles in a month are required for reliable long-term trend detection. When ignoring the vertical correlation, we found that a typical sampling strategy (i.e. four profiles per month) might result in 7 % of sampled trends falling outside the 2σ uncertainty interval derived from the full dataset with an associated 10 % of mean absolute percentage error. Based on a series of sensitivity studies, we determined optimal sampling frequencies for (1) basic trend detection and (2) accurate quantification of the trend. When applying the integrated fit method, we find that a typical sampling frequency of four profiles per month is adequate for basic trend detection; however, accurate quantification of the trend requires 14 profiles per month. Accurate trend quantification can be achieved with only 10 profiles per month if a regular sampling frequency is applied. In contrast, the standard separated fit method, which ignores the vertical correlation between pressure surfaces, requires 8 profiles per month for basic trend detection and 18 profiles per month for accurate trend quantification. While our method improves trend detection from sparse datasets, the key to substantially reducing the uncertainty is to increase the sampling frequency.
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Inness, A., F. Baier, A. Benedetti, I. Bouarar, S. Chabrillat, H. Clark, C. Clerbaux, et al. "The MACC reanalysis: an 8-yr data set of atmospheric composition." Atmospheric Chemistry and Physics Discussions 12, no. 12 (December 5, 2012): 31247–347. http://dx.doi.org/10.5194/acpd-12-31247-2012.
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Abstract. An eight-year long reanalysis of atmospheric composition data covering the period 2003–2010 was constructed as part of the FP7 funded Monitoring Atmospheric Composition and Climate project by assimilating satellite data into a global model and data assimilation system. This reanalysis provides fields of chemically reactive gases, namely carbon monoxide, ozone, nitrogen oxides, and formaldehyde, as well as aerosols and greenhouse gases globally at a resolution of about 80 km for both the troposphere and the stratosphere. This paper describes the assimilation system for the reactive gases and presents validation results for the reactive gases analysis fields to document the dataset and to give a first indication of its quality. Tropospheric CO values from the MACC reanalysis are on average 10–20% lower than routine observations from commercial aircrafts over airports through most of the troposphere, and have larger negative biases in the boundary layer at urban sites affected by air pollution, possibly due to an underestimation of CO or precursor emissions. Stratospheric ozone fields from the MACC reanalysis agree with ozone sondes and ACE-FTS data to within ±10% in most situations. In the troposphere the reanalysis shows biases of −5% to +10% with respect to ozone sondes and aircraft data in the extratropics, but has larger negative biases in the tropics. Area averaged total column ozone agrees with ozone fields from a multi sensor reanalysis data set to within a few percent. NO2 fields from the reanalysis show the right seasonality over polluted urban areas of the NH and over tropical biomass burning areas, but underestimate wintertime NO2 maxima over anthropogenic pollution regions and overestimate NO2 in Northern and Southern Africa during the tropical biomass burning seasons. Tropospheric HCHO is well simulated in the MACC reanalysis even though no satellite data are assimilated. It shows good agreement with independent SCIAMACHY retrievals over regions dominated by biogenic emissions with some anthropogenic input, such as the Eastern US and China, and also over African regions influenced by biogenic sources and biomass burning.
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Inness, A., F. Baier, A. Benedetti, I. Bouarar, S. Chabrillat, H. Clark, C. Clerbaux, et al. "The MACC reanalysis: an 8 yr data set of atmospheric composition." Atmospheric Chemistry and Physics 13, no. 8 (April 18, 2013): 4073–109. http://dx.doi.org/10.5194/acp-13-4073-2013.
Full textAbstract:
Abstract. An eight-year long reanalysis of atmospheric composition data covering the period 2003–2010 was constructed as part of the FP7-funded Monitoring Atmospheric Composition and Climate project by assimilating satellite data into a global model and data assimilation system. This reanalysis provides fields of chemically reactive gases, namely carbon monoxide, ozone, nitrogen oxides, and formaldehyde, as well as aerosols and greenhouse gases globally at a horizontal resolution of about 80 km for both the troposphere and the stratosphere. This paper describes the assimilation system for the reactive gases and presents validation results for the reactive gas analysis fields to document the data set and to give a first indication of its quality. Tropospheric CO values from the MACC reanalysis are on average 10–20% lower than routine observations from commercial aircrafts over airports through most of the troposphere, and have larger negative biases in the boundary layer at urban sites affected by air pollution, possibly due to an underestimation of CO or precursor emissions. Stratospheric ozone fields from the MACC reanalysis agree with ozonesondes and ACE-FTS data to within ±10% in most seasons and regions. In the troposphere the reanalysis shows biases of −5% to +10% with respect to ozonesondes and aircraft data in the extratropics, but has larger negative biases in the tropics. Area-averaged total column ozone agrees with ozone fields from a multi-sensor reanalysis data set to within a few percent. NO2 fields from the reanalysis show the right seasonality over polluted urban areas of the NH and over tropical biomass burning areas, but underestimate wintertime NO2 maxima over anthropogenic pollution regions and overestimate NO2 in northern and southern Africa during the tropical biomass burning seasons. Tropospheric HCHO is well simulated in the MACC reanalysis even though no satellite data are assimilated. It shows good agreement with independent SCIAMACHY retrievals over regions dominated by biogenic emissions with some anthropogenic input, such as the eastern US and China, and also over African regions influenced by biogenic sources and biomass burning.
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Liangzi, Wang, Ju Haitao, Li Qing, Qin Dong, Wang Lianjie, Yu Yingrui, Ning Zhonghao, et al. "MULTIPLE CHOICES OF REACTOR CORE NUCLEAR DESIGN FOR ACP100’S APPLICATION IN DIFFERENT SCENARIOS." EPJ Web of Conferences 247 (2021): 19002. http://dx.doi.org/10.1051/epjconf/202124719002.
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ACP100 NPP designed by CNNC (China National Nuclear Corporation) is a 125MWe, multi-purpose small modular reactor based on pressurized water reactor technology; it adopts the integrated reactor technology. Different application scenarios bring up different design requirements: some require high compactness, but others care more about a longer cycle length, and some may require a fully mature and conservative design; thus, multiple design choices need to be proposed. Also, the same and most important thing cared by all users is that, the design needs to be validated to satisfy the current nuclear safety standards, and lower cost would be always preferred. Core nuclear design is a key part of the whole NPP design. Basically, nuclear design target of ACP100 is to achieve a reasonable good balance during longer cycle length, larger discharge exposure for fuel assemblies, and maximally using the mature technologies, and of course, with sufficient reactivity control ability for safety assurance. Aiming at satisfying all these different needs maximally, a strategy of supplying multiple nuclear design choices is proposed for ACP100: choice 1. Boron-free plan, this is a compact design with no need for chemistry and volume system, no need for daily boron adjustment and relative waste storage; choice 2. Boron and rod co-controlled plan, this is similar with large commercial PWRs, with a lower power peak factor and suitable for broad location sites. Both choices load 57 units of the same type fuel assemblies CF3S (with height reduced from CF3 fuel assemblies) per cycle, and both adopt partial reload and shuffle fuel management strategy to achieve larger discharge exposure. Gd is loaded in the fuel rods in both choices to help control reactivity. Choice 1 loads much more control rod clusters than choice 2, and of course, reactivity adjustment and compensation during operation is totally different between them. Using suitable and reliable software to simulate the core, through large amount of optimization, both choices achieve a 24-month fuel cycle length; the average discharge exposure of fuel assemblies reach about 40000MWd/tU, which is competitive among SMRs, especially for boron-free ones; and sufficient reactivity control ability and safety margin is validated to fully meet the reactor safety requirements.
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Mühle, Jens, Cathy M. Trudinger, Luke M. Western, Matthew Rigby, Martin K. Vollmer, Sunyoung Park, Alistair J. Manning, et al. "Perfluorocyclobutane (PFC-318, <i>c</i>-C<sub>4</sub>F<sub>8</sub>) in the global atmosphere." Atmospheric Chemistry and Physics 19, no. 15 (August 14, 2019): 10335–59. http://dx.doi.org/10.5194/acp-19-10335-2019.
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Abstract. We reconstruct atmospheric abundances of the potent greenhouse gas c-C4F8 (perfluorocyclobutane, perfluorocarbon PFC-318) from measurements of in situ, archived, firn, and aircraft air samples with precisions of ∼1 %–2 % reported on the SIO-14 gravimetric calibration scale. Combined with inverse methods, we found near-zero atmospheric abundances from the early 1900s to the early 1960s, after which they rose sharply, reaching 1.66 ppt (parts per trillion dry-air mole fraction) in 2017. Global c-C4F8 emissions rose from near zero in the 1960s to 1.2±0.1 (1σ) Gg yr−1 in the late 1970s to late 1980s, then declined to 0.77±0.03 Gg yr−1 in the mid-1990s to early 2000s, followed by a rise since the early 2000s to 2.20±0.05 Gg yr−1 in 2017. These emissions are significantly larger than inventory-based emission estimates. Estimated emissions from eastern Asia rose from 0.36 Gg yr−1 in 2010 to 0.73 Gg yr−1 in 2016 and 2017, 31 % of global emissions, mostly from eastern China. We estimate emissions of 0.14 Gg yr−1 from northern and central India in 2016 and find evidence for significant emissions from Russia. In contrast, recent emissions from northwestern Europe and Australia are estimated to be small (≤1 % each). We suggest that emissions from China, India, and Russia are likely related to production of polytetrafluoroethylene (PTFE, “Teflon”) and other fluoropolymers and fluorochemicals that are based on the pyrolysis of hydrochlorofluorocarbon HCFC-22 (CHClF2) in which c-C4F8 is a known by-product. The semiconductor sector, where c-C4F8 is used, is estimated to be a small source, at least in South Korea, Japan, Taiwan, and Europe. Without an obvious correlation with population density, incineration of waste-containing fluoropolymers is probably a minor source, and we find no evidence of emissions from electrolytic production of aluminum in Australia. While many possible emissive uses of c-C4F8 are known and though we cannot categorically exclude unknown sources, the start of significant emissions may well be related to the advent of commercial PTFE production in 1947. Process controls or abatement to reduce the c-C4F8 by-product were probably not in place in the early decades, explaining the increase in emissions in the 1960s and 1970s. With the advent of by-product reporting requirements to the United Nations Framework Convention on Climate Change (UNFCCC) in the 1990s, concern about climate change and product stewardship, abatement, and perhaps the collection of c-C4F8 by-product for use in the semiconductor industry where it can be easily abated, it is conceivable that emissions in developed countries were stabilized and then reduced, explaining the observed emission reduction in the 1980s and 1990s. Concurrently, production of PTFE in China began to increase rapidly. Without emission reduction requirements, it is plausible that global emissions today are dominated by China and other developing countries. We predict that c-C4F8 emissions will continue to rise and that c-C4F8 will become the second most important emitted PFC in terms of CO2-equivalent emissions within a year or two. The 2017 radiative forcing of c-C4F8 (0.52 mW m−2) is small but emissions of c-C4F8 and other PFCs, due to their very long atmospheric lifetimes, essentially permanently alter Earth's radiative budget and should be reduced. Significant emissions inferred outside of the investigated regions clearly show that observational capabilities and reporting requirements need to be improved to understand global and country-scale emissions of PFCs and other synthetic greenhouse gases and ozone-depleting substances.
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Martynyuk, V. A., V. A. Trudonoshin, and V. G. Fedoruk. "Analysing Mechanical Systems in Domestic and Foreign CAD Systems." Mechanical Engineering and Computer Science, no. 6 (July 26, 2018): 10–17. http://dx.doi.org/10.24108/0618.0001404.
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The article considers applications of foreign CAD-systems in creating the challenging projects at domestic enterprises and design bureaus. As stated in the article "... presently, there is no domestic CAD-system that could completely replace such foreign products as NX, CATIA, Credo". Besides, due to international cooperation in creating the challenging projects (for example, the project to create a modern wide-body aircraft, proposed jointly with China), it makes sense to use the worldwide known and popular CAD systems (the aforementioned NX, CATIA, Credo). Therefore, in the foreseeable future, we will still have to use foreign software products. Of course, there always remains a question of the reliability of the results obtained. Actually, this question is always open regardless of what software product is used - domestic or foreign. This question has been haunting both developers and users of CAD systems for the last 30 to 40 years. But with using domestic systems, it is much easier to identify the cause of inaccurate results and correct the mathematical models used, the methods of numerical integration applied, and the solution of systems of nonlinear algebraic systems. Everything is much more complicated if we use a foreign software product. All advertising conversations that there is a tool to make the detected errors available to the developers, remain only conversations in the real world. It is easily understandable to domestic users, and, especially, to domestic developers of similar software products. The existing development rates and competition for potential buyers dictate a rigid framework of deadlines for releasing all new versions of the product and introducing the latest developments into commercial product, etc. As a result, the known errors migrate from version to version, and many users have accepted it long ago. Especially, this concerns the less popular tools rather than the most popular applications (modules) of a CAD system. For example, in CAD systems, the "Modeling" module where geometric models of designed parts and assembly units are created has been repeatedly crosschecked. But most of the errors are hidden in applications related to the design of parts from sheet material and to the pipeline design, as well as in applications related to the analysis of moving mechanisms and to the strength or gas dynamic analysis by the finite element method.The article gives a concrete example of a moving mechanism in the analysis of which an error was detected using the mathematical model of external influence (a source of speed) in the NX 10.0 system of Siemens.
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Cao, Xian, Gang Zhao, and Wenlei Xiao. "Digital Twin–oriented real-time cutting simulation for intelligent computer numerical control machining." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, July 15, 2020, 095440542093786. http://dx.doi.org/10.1177/0954405420937869.
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Digital Twin has become a frontier research topic in recent years and the important development direction of intelligent manufacturing. For numerical control machining, a Digital Twin system can be used as an intelligent monitoring and analysis center by reflecting the real machining process in a virtual environment. The machining simulation is the key technology to realize this kind of application. However, existing machining simulation systems are designed for off-line situation that cannot be used directly in Digital Twin environment. The challenges for machining simulation are analyzed and explained in this article: (1) complete process data representation in simulation system; (2) executing in cooperating with computer numerical control system; (3) more efficient simulation algorithm. In order to meet these challenges, a new machining simulation system is proposed. STEP-NC standard is used to save complete process data exported from the computer-aided manufacturing system and synchronization algorithm is developed based on the communication data of computer numerical control system. Most importantly, an optimized tri-dexel-based machining simulation algorithm is developed to perform high efficiency that can follow the real machining process. Finally, a Digital Twin system for NC machining is presented that has been tested and verified in a workshop located in COMAC (Commercial Aircraft Corporation of China Ltd).
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Braun, R. J., M. Gummalla, and J. Yamanis. "System Architectures for Solid Oxide Fuel Cell-Based Auxiliary Power Units in Future Commercial Aircraft Applications." Journal of Fuel Cell Science and Technology 6, no. 3 (May 15, 2009). http://dx.doi.org/10.1115/1.3008037.
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Recent advancements in fuel cell technology through the auspices of the Department of Energy, the National Aeronautics and Space Administration, and industry partners have set the stage for the use of solid oxide fuel cell (SOFC) power generation systems in aircraft applications. Conventional gas turbine auxiliary power units (APUs) account for 20% of airport ground-based emissions. Alleviating airport ground emissions will continue to be a challenge with increased air travel unless new technology is introduced. Mission fuel burn and emissions can be significantly reduced through optimal systems integration of aircraft and SOFC subsystems. This study examines the potential total aircraft mission benefits of tightly integrating SOFC hybrids with aircraft subsystems using United Technologies Corporation Integrated Total Aircraft Power Systems proprietary methodologies. Several system concepts for optimal integration of the SOFC stack with aircraft subsystems are presented and analyzed in terms of mission fuel burn for technologies commensurate with 2015 entry into service. The performance of various hybrid SOFC-APU system architectures is compared against an advanced gas turbine-based APU system. In addition to the merits of different system architectures, optimal SOFC system parameter selection is discussed. The results of the study indicate that despite the lower power density of SOFC-based APU systems, significant aircraft fuel burn (5–7%) and emission reductions (up to 70%) are possible. The majority of the fuel burn savings are realized during aircraft ground operations rather than in-flight mission segments due to the greater efficiency difference between the SOFC system and the advanced APU technology.
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Shaikh Abdul Karim, Sarah, Fariza Anis Md Tahir, Umul Khair Mohamad, Marlina Abu Bakar, Khairul Nizam Mohamad, Maria Suleiman, Hussein Omar Khan, and Julina Md Noor. "Experience repatriation of citizens from epicentre using commercial flights during COVID-19 pandemic." International Journal of Emergency Medicine 13, no. 1 (October 28, 2020). http://dx.doi.org/10.1186/s12245-020-00308-7.
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Abstract Background During the COVID-19 pandemic, many countries instituted closure of borders from international and local travels. Stranded citizens appeal to their governments to embark on citizen repatriation missions. Between February and April 2020, the Government of Malaysia directed repatriation of its citizens from China, Iran, Italy and Indonesia. We describe the preparation and execution of the repatriation mission using chartered commercial aircraft. The mission objectives were to repatriate as many citizens based on aircraft capacity and prevent onboard transmission of the disease to flight personnel. Results Five repatriation missions performed was led by the National Agency for Disaster Management (NADMA) with the Ministry of Health providing technical expertise. A total of 432 citizens were repatriated from the missions. The operations were divided into four phases: the pre-boarding screening phase, the boarding and in-flight phase, the reception phase and the quarantine phase. The commercial aircraft used were from two different commercial airlines. Each mission had flight crew members between 10 and 17 people. There were 82 positive cases detected among the repatriated citizens. There was a single positive case of a healthcare worker involved in the mission, based on the sample taken on arrival of the flight. There were no infections involving flight team members. Conclusion Medical flight crew must be familiar with aircraft fittings that differ from one commercial airline to another as it influences infection control practices. A clear understanding of socio-political situation of a country, transmission routes of a pathogen, disease presentation, and knowledge of aviation procedures, aircraft engineering and design is of great importance in preparing for such missions. Our approach of multidiscipline team involvement managed to allow us to provide and execute the operations successfully.
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Thorley, Martin, and Andreas Fulda. "The Importance of Leverage in GlaxoSmithKline’s China Engagement: A Revelatory Case Study." Journal of Current Chinese Affairs, July 9, 2020, 186810262093186. http://dx.doi.org/10.1177/1868102620931862.
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This article critically examines multinational corporation (MNC)–host government relations in the People’s Republic of China (PRC) through the prism of the GlaxoSmithKline (GSK) corruption scandal. The article takes the episode as a revelatory case study and analyses it with a view to uncovering further data on the imperatives that govern interactions between the PRC and MNCs. Drawing upon the theoretical framework provided by David M. Anderson’s conception of leverage, the authors attempt to unite the two themes of cultural analysis and commercial analysis. By highlighting both the rising commercial risks for MNCs and considerable legal risks for Chinese and non-Chinese intermediaries working on their behalf, the case itself underlines a gulf between theoretical understanding and practical experience of engagement with China in this sphere. The authors argue that the GSK corruption case demonstrates both that MNC normative bargaining leverage (the use of standards and norms, considered legitimate by both sides, to gain advantage or protect one’s position) in the PRC is illusory and that the Chinese party-state possesses far greater negative bargaining leverage (leverage based upon the capacity to make the other side worse off) than typically assumed.
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"Industry Watch." Asia-Pacific Biotech News 12, no. 05 (March 2008): 36–63. http://dx.doi.org/10.1142/s021903030800030x.
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Invitrogen Enters into a Licensing Agreement with IMBcom. Stem Cell Sciences Enters into an Agreement with Myelin Repair Foundation. European Company NovaSecta Joins First Chinese CRO Service Alliance for Drug Discovery Solutions. DuPont (DD) Opens Fluoropolymer Production Plant in China. Satyam Opens Center to Cater to Life Sciences Industry. Eisai and Accenture Launch Clinical Data Management in India. Sanofi Pasteur and Statens Serum Institute Team Up against Tuberculosis. Roche Diagnostics and Mankind Pharma Collaborate on Accu-Chek Go. Nicholas Unit Signs Drug Development Pact with Eli Lilly & Co. Pierre Fabre and Nicholas Piramal Sign Oncology Research Agreement. Fortis HealthWorld Works with Godrej Aadhaar to Reach Out to Rural Areas in India. Karo Bio and Zydus Cadila Sign Research Agreement. ICGEB Joins with Emory Vaccine Center. DiscoveRx Corporation Signs Agreement with Cosmo Bio. Sysmex and bioMérieux Form Commercial Joint Venture for the Japanese In Vitro Diagnostics Market. Progeniq Launches Next-generation BioBoost v4.0 Accelerator. Celltrion and CSL Announce Collaboration to Develop and Manufacture Monoclonal Antibody. Antitope Ltd Announces Research Agreement with China Synthetic Rubber Corporation. Merck and DCB Announce Cooperation to Create New Biotech Services and Training Center. Taiwan's PharmaEssentia Signs Deal with Malaysia's Black Gold Global.
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"Industry Watch." Asia-Pacific Biotech News 12, no. 09 (July 2008): 56–71. http://dx.doi.org/10.1142/s0219030308000608.
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Arana and greenovation in Anticancer Co-development Deal. AMAG Pharmaceuticals and 3Sbio to Develop Ferumoxytol in China. Biocon Launches Prefiled Syringes for Cancer. Ranbaxy Ties up with Yemen's Pharma. Cato Research and Neuland Laboratories Form Joint Venture in India. Alnylam, Takeda Ink RNAi Deal. Seahorse Bioscience Enters into Agreement with Primetech Corporation to Bring XF Technology to Japan. Faust Pharmaceuticals Announces Research Agreement with Takeda. Agilent Technologies Introduces First Commercial GC/MS Metabolite Library. Innogene and NCCS Starts Clinical Trial for Drug to Treat Head and Neck Cancer. Walter Reed Army Institute of Research and Siam Life Science Develop New Gold Standard for Pharmacological and Toxicological Test Systems.
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Au, Anson. "FinTech innovation and knowledge flows in Hong Kong’s financial sector: a social network analysis approach." Journal of Asia Business Studies ahead-of-print, ahead-of-print (February 8, 2021). http://dx.doi.org/10.1108/jabs-09-2020-0381.
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Purpose This paper aims to examine how financial technology (FinTech) knowledge from foreign firms flows into and among elite commercial banks in Hong Kong’s financial sector to drive innovation. Design/methodology/approach Using social network analysis and regression analysis on a novel database of patents held by Hong Kong’s elite commercial banks, this paper examines the relationships between network position and FinTech knowledge flow. Findings This paper finds four untold patterns of innovation and inequality in Hong Kong’s financial sector: only three banks are responsible for all the FinTech knowledge entering Hong Kong; most foreign FinTech comes from the USA through Hong Kong and Shanghai Banking Corporation, whereas most FinTech from China enters through Fubon Bank and Development Bank of Singapore; older banks and banks with more connections to firms inside Asia are more likely to import FinTech; the most beneficial sources of FinTech for a bank’s network position are firms from outside Asia. Originality/value Despite the well-documented volumes of cross-border and cross-continental movement of financial institutions in Hong Kong, there is little work on the knowledge flows that underwrite this mobility. This paper addresses this gap by using FinTech knowledge flows to map the distribution of innovation, network position and competitive advantage in Hong Kong’s financial sector.
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Bao, Danwen, Shijia Tian, Ziqian Zhang, Hao Cheng, Ting Zhu, and Nicholas Carpeggiani. "Spatial-Temporal Patterns of Air Pollutant Emissions From Landing and Take-Off Cycles in the Yangtze River Delta of China During the COVID-19 Outbreak." Frontiers in Public Health 9 (September 7, 2021). http://dx.doi.org/10.3389/fpubh.2021.673666.
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The global aviation industry has been experiencing catastrophic disruption since the beginning of 2020 due to the unprecedented impact of the COVID-19 pandemic on air traffic. Although the decline in regular commercial air travel has caused tremendous economic loss to aviation stakeholders, it has also led to the reduction in the amount of recorded air pollutants. Most of the aircraft emissions are released during the cruise phase of flight, however they have relatively small impact on humans due to the fact that those emissions are released directly into the upper troposphere and lower stratosphere. Therefore, the scope of this study is to investigate the ground-level aircraft emissions from landing and take-off (LTO) cycles, as they have a greater influence on the ambient environment of the airports in a specific region. In this paper, we study the variation of typical air pollutant concentrations (i.e., HC, CO, and NOx) from the LTO cycles during the outbreak of COVID-19 pandemic in both temporal and spatial scales. These ground-level emissions are estimated for the 22 airports in the Yangtze River Delta, China. The results indicate that the variation pattern of the three air pollutants were significantly influenced by the dramatic onset of the COVID-19 pandemic, as well as the pertinent policies to suppress the spread of the virus. The results also reveal non-uniform distribution of the emission quantified at different airports. It is noticeable that the emission quantity generally declined from the east coast to the central and western part of the research region. Furthermore, discrepancies in the target markets also create disparities in the variation pattern of the emissions at different airports under the context of COVID-19.
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Gaudel, A., O. R. Cooper, G. Ancellet, B. Barret, A. Boynard, J. P. Burrows, C. Clerbaux, et al. "Tropospheric Ozone Assessment Report: Present-day distribution and trends of tropospheric ozone relevant to climate and global atmospheric chemistry model evaluation." Elementa: Science of the Anthropocene 6 (January 1, 2018). http://dx.doi.org/10.1525/elementa.291.
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The Tropospheric Ozone Assessment Report (TOAR) is an activity of the International Global Atmospheric Chemistry Project. This paper is a component of the report, focusing on the present-day distribution and trends of tropospheric ozone relevant to climate and global atmospheric chemistry model evaluation. Utilizing the TOAR surface ozone database, several figures present the global distribution and trends of daytime average ozone at 2702 non-urban monitoring sites, highlighting the regions and seasons of the world with the greatest ozone levels. Similarly, ozonesonde and commercial aircraft observations reveal ozone’s distribution throughout the depth of the free troposphere. Long-term surface observations are limited in their global spatial coverage, but data from remote locations indicate that ozone in the 21st century is greater than during the 1970s and 1980s. While some remote sites and many sites in the heavily polluted regions of East Asia show ozone increases since 2000, many others show decreases and there is no clear global pattern for surface ozone changes since 2000. Two new satellite products provide detailed views of ozone in the lower troposphere across East Asia and Europe, revealing the full spatial extent of the spring and summer ozone enhancements across eastern China that cannot be assessed from limited surface observations. Sufficient data are now available (ozonesondes, satellite, aircraft) across the tropics from South America eastwards to the western Pacific Ocean, to indicate a likely tropospheric column ozone increase since the 1990s. The 2014–2016 mean tropospheric ozone burden (TOB) between 60°N–60°S from five satellite products is 300 Tg ± 4%. While this agreement is excellent, the products differ in their quantification of TOB trends and further work is required to reconcile the differences. Satellites can now estimate ozone’s global long-wave radiative effect, but evaluation is difficult due to limited in situ observations where the radiative effect is greatest.
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Volinchak, Crystal M., Erin M. Whitehouse, Matthew R. Yourstowsky, Robert G. Woolley, and Birsen Karpak. "ANALYZING CORPORATE EXPANSION TO INTERNATIONAL MARKETS: THE CASE OF GERMANY, UNITED KINGDOM, CANADA, MEXICO AND CHINA." International Journal of the Analytic Hierarchy Process 10, no. 1 (April 24, 2018). http://dx.doi.org/10.13033/ijahp.v10i1.574.
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In this study, the authors utilized the Analytic Hierarchy Process (AHP) decision-making model to select the optimal market for international expansion for ABC Corporation located in Ohio[1]. The benefits of exporting to nine different countries: Germany, the United Kingdom, Canada, Mexico, Netherlands, China, United Arab Emirates, Australia and Brazil were analyzed. For the sake of more precise and in-depth research, preliminary studies performed on these nine countries were used to determine the top five markets: China, Mexico, Canada, Germany and the United Kingdom. Preliminary research included multiple factors about these nine countries. Market size, market growth rate, market consumption capacity, market intensity, market receptivity, commercial infrastructure, trade barriers, contribution margins, country risk and the growth rate of construction were the qualitative and quantitative criteria specifically considered. The importance of each criteria and sub-criteria were determined with export market experts and company decision makers. The AHP analysis enabled the authors to determine the best possible export market for the company by evaluating the data from China, Mexico, Canada, Germany and the United Kingdom. The robustness of the results was tested using sensitivity analysis. Sensitivity analysis results were then discussed with the decision makers. The best market was selected and alternative markets were presented with degrees of preference. Managerial implications of the study and future research directions will be discussed.
[1] Company name has been disguised for confidentiality reasons.
-This paper received “Best Student Achievement in International Business Award for Graduate Students”, Youngstown State University, Williamson College of Business, April 18, 2018.
-Acknowledgement: This project allowed our group to become better researchers, taught us how
to use AHP methodology in real - life decision making and allowed us to network with colleagues around the world. This was a fantastic experience for all of us and it will not be forgotten. Being able to represent Youngstown State University at the MCDM, 2017 Conference was an honor. We learned and did things that students cannot learn in the classroom. Working alongside Dr. Karpak allowed us to have a hands - on experience with the project and she was there when questions needed addressed. We feel that our research benefitted ABC and allowed them to gain a better understanding of what market they should export to. We are beyond grateful for this experience and glad that we were selected to go to Ottawa, Canada and to now be submitting our research to the IJAHP journal. The authors also thank the export expert Mr. Mousa Kassis, CGBP, Director, Ohio Small Business Development Center (SBDC) Export Assistance Network, Williamson College of Business Administration of Youngstown State University, for identifying ABC Company and giving his expert judgments on criteria evaluations.