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Schmeling D, Shishkin A, Schiepel D, Wagner C. Numerical and experimental study of aerosol dispersion in the Do728 aircraft cabin. CEAS AERONAUTICAL JOURNAL 2023; 14:509-526. [PMID: 36819984 PMCID: PMC9930724 DOI: 10.1007/s13272-023-00644-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 12/20/2022] [Accepted: 01/18/2023] [Indexed: 05/24/2023]
Abstract
The dispersion of aerosols originating from one source, the 'index' passenger, within the cabin of the aircraft Do728 is studied experimentally using an aerosol-exhaling thermal manikin and in Reynolds-averaged Navier-Stokes simulations (RANS). The overall aim of the present study is the experimental determination of the aerosol spreading for the state-of-the-art mixing ventilation (MV) and to evaluate the potential of alternative ventilation concepts for controlling the aerosol spreading in RANS. For MV, the experiments showed that the ratio of inhaled to exhaled aerosol particles drops below 0.06% (volume ratio) for distances larger than two seat rows from the source. However, within a single row, the observed ratio is higher. Further, the dispersion is much weaker for a standing than for a seated index passenger. High air exchange rates and a well-guided flow prevent a dispersion of the aerosols in high concentrations over larger distances. Additionally, the positive effect of a mask and an increased air flow rate, and especially their combination are shown. In the complementary conducted RANS, the advantages of floor-based cabin displacement ventilation (CDV) which is alternative ventilation concept to MV, regarding spreading lengths and the dwell time of the aerosols in the cabin were determined. The obtained results also underline the importance of the flow field for the aerosol dispersion. Further, additional unsteady RANS (URANS) simulations of the short-term process of the initial aerosol cloud formation highlighted that the momentum decay of the breathing and the evaporation processes take place within a few seconds only. Supplementary Information The online version contains supplementary material available at 10.1007/s13272-023-00644-3.
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Affiliation(s)
- D. Schmeling
- German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology, Bunsenstr. 10, 37073 Göttingen, Germany
| | - A. Shishkin
- German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology, Bunsenstr. 10, 37073 Göttingen, Germany
| | - D. Schiepel
- German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology, Bunsenstr. 10, 37073 Göttingen, Germany
| | - C. Wagner
- German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology, Bunsenstr. 10, 37073 Göttingen, Germany
- Institute of Thermodynamics and Fluid Mechanics, Technische Universität Ilmenau, Am Helmholtzring 1, 98683 Ilmenau, Germany
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Sun X, Wandelt S, Zhang A. COVID-19 pandemic and air transportation: Summary of Recent Research, Policy Consideration and Future Research Directions. TRANSPORTATION RESEARCH INTERDISCIPLINARY PERSPECTIVES 2022; 16:100718. [PMID: 36407295 PMCID: PMC9640395 DOI: 10.1016/j.trip.2022.100718] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/02/2022] [Accepted: 11/06/2022] [Indexed: 05/19/2023]
Abstract
The COVID-19 pandemic can be considered an unparalleled disruption to the aviation industry in the last century. Starting with an at-that-time inconceivable reduction in the number of flights from March 2020 to May 2020, the aviation industry has been trying to navigate through and out of the crisis. This process is accompanied with a significant number of scientific studies, reporting on the direct and indirect impact of the COVID-19 pandemic on aviation and vice versa. This paper reviews the impacts in context of the recent literature. We have collected nearly 200 well-published papers on the subject in the years 2021/2022 and dissected them into a framework of eight categories, built around: airlines, airports, passengers, workforce, markets, contagion, sustainability, and economics. We highlight the essence of findings in the literature and derive a set of future research directions and policy considerations which we deem important on the way towards pandemic-resilient aviation.
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Affiliation(s)
- Xiaoqian Sun
- National Key Laboratory of CNS/ATM, School of Electronic and Information Engineering, Beihang University, 100191 Beijing, China
| | - Sebastian Wandelt
- National Key Laboratory of CNS/ATM, School of Electronic and Information Engineering, Beihang University, 100191 Beijing, China
| | - Anming Zhang
- Sauder School of Business, University of British Columbia, Vancouver, BC, Canada
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Bai S, Yu D, Yang M, Tang R, He H, Zhao J, Huang P. Is negative e-WOM more powerful? Multimodal data analysis on air passengers’ perception of COVID-19 safety measures. Front Psychol 2022; 13:983987. [PMID: 36329743 PMCID: PMC9624191 DOI: 10.3389/fpsyg.2022.983987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022] Open
Abstract
During the normalization stage of the COVID-19 epidemic prevention and control, the safety threats caused by improper epidemic prevention measures of airlines have become the primary concern for air passengers. Negative e-WOM related to safety perception obtained based on online multimodal reviews of travel websites has become an important decision-making basis for potential air passengers when making airline choices. This study aims to examine the relationship between potential air passengers’ negative safety perception and the usefulness of online reviews, as well as to test the moderating effect of review modality and airline type. It also further explores the effectiveness and feasibility of applying big data sentiment analysis to e-WOM management. To this end, the theoretical model of negative safety perception, review modality, and airline type affecting review usefulness was constructed. Then we select 10 low-cost airlines and 10 full-service airlines, respectively, according to the number of reviews sorted by the TripAdvisor website, and use crawling techniques to obtain 10,485 reviews related to COVID-19 safety of the above companies from December 2019 to date, and conduct safety perception sentiment analysis based on Python’s Textblob library. Finally, to avoid data overdispersion, the model is empirically analyzed by negative binomial regression using R software. The results indicate that (1) Negative safety perception significantly and negatively affects review usefulness, that is, extreme negative safety perception can provide higher review usefulness for potential air passengers. (2) Review modality and airline type have a significant moderating effect on the relationship between negative safety perception and review usefulness, in which multimodal reviews and full-service airlines both weakened the negative impact of negative safety perception on review usefulness. The theoretical model in this paper is both an extension of the application of big data sentiment analysis techniques and a beneficial supplement to current research findings of e-WOM, providing an important reference for potential air passengers to identify useful reviews accurately and thus reduce safety risks in online decision-making.
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Affiliation(s)
- Shizhen Bai
- School of Management, Harbin University of Commerce, Harbin, China
| | - Dingyao Yu
- School of Management, Harbin University of Commerce, Harbin, China
| | - Mu Yang
- Department of Management, Birkbeck, University of London, London, United Kingdom
- *Correspondence: Mu Yang,
| | - Rui Tang
- School of Economics Teaching and Research, Party School of the Central Committee of C.P.C (Chinese Academy of Governance), Beijing, China
| | - Hao He
- School of Management, Harbin University of Commerce, Harbin, China
| | - Jiayuan Zhao
- School of Computer and Information Engineering, Harbin University of Commerce, Harbin, China
| | - Peihua Huang
- School of Management, Harbin University of Commerce, Harbin, China
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Liao M, Wu C, Yan H. Recovery of Chinese low-cost carriers after the outbreak of COVID-19 pandemic. JOURNAL OF AIR TRANSPORT MANAGEMENT 2022; 105:102282. [PMID: 35975184 PMCID: PMC9372088 DOI: 10.1016/j.jairtraman.2022.102282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
This study conducts a detailed analysis of the response of China's low-cost carriers (LCCs) to the threats posed by the pandemic from a route network perspective, aiming to explore the resilience of LCCs and Chinese airlines. Using geographic visualization and network analysis, we evaluate and compare the network connectivity of each Chinese LCC to see the change patterns, then elaborate on the network connection of Spring Airlines. The major results are: the LCC sector has not recovered, but some of them exceed the pre-pandemic levels in a less deregulated environment; different LCCs show different recovery patterns; Spring Airlines outperforms the other four LCCs in terms of network connectivity. The recovery process is supported by various external factors, such as the reduction of new confirmed COVID-19 local cases and international flights, the re-open of inter-provincial tour groups and tourism demand, the nationwide rebound activities promoted by the central government, and the supporting policies, especially new slot allocation processes issued by CAAC. The case study further indicates the effects of high-speed rail (HSR) and regional subsidy measures on the tactical actions of Springs in route planning. This paper serves as a referential case for the LCCs worldwide and has good application for the recovery of other LCCs in other countries. Moreover, the study conducted in this time window offers a chance to assess the development of Chinese airlines in a not fully deregulated aviation environment. It contributes to the debate on the theory of air network resilience.
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Affiliation(s)
- Maozhu Liao
- Sauder School of Business, University of British Columbia, 2053 Main Mall, Vancouver, BC V6T 1Z2, Canada
| | - Chuntao Wu
- School of Tourism, Sichuan University, No. 2 South Section, Yihuan Road, Chengdu, Sichuan, 610064, PR China
| | - Hongmeng Yan
- School of Tourism, Sichuan University, No. 2 South Section, Yihuan Road, Chengdu, Sichuan, 610064, PR China
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Acosta RW, Visser JT, Chen LH, Leggat PA, Flaherty GT. Adaptation of travel medicine practitioners to the COVID-19 pandemic: a cross-sectional survey of ISTM members. J Travel Med 2022; 29:6541666. [PMID: 35238928 PMCID: PMC9383496 DOI: 10.1093/jtm/taac032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 11/16/2022]
Abstract
This cross-sectional study evaluated the adaptations of current International Society of Travel Medicine (ISTM) members in relation to the disruption caused by the coronavirus disease 2019 (COVID-19) pandemic. It demonstrates that the majority of members remain engaged with travel medicine and ISTM educational activities, while adapting to COVID-related clinical demands.
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Affiliation(s)
| | | | - Lin H Chen
- Division of Infectious Diseases and Travel Medicine, Mount Auburn Hospital, Cambridge, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Peter A Leggat
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Australia.,School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Gerard T Flaherty
- School of Medicine, National University of Ireland Galway, Galway, Ireland.,School of Medicine, International Medical University, Kuala Lumpur, Malaysia
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Wu C, Yan H, Xue W, Liao M. The operation of labour charter flights during the COVID-19 pandemic in China. CASE STUDIES ON TRANSPORT POLICY 2022; 10:427-433. [PMID: 35036314 PMCID: PMC8743854 DOI: 10.1016/j.cstp.2022.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/12/2021] [Accepted: 01/04/2022] [Indexed: 05/12/2023]
Abstract
China was the first market badly hit by the COVID-19 pandemic. This paper explores how Chinese airlines started and involved in labour charter operations, and tanalyse the evolutionary patterns of the charter route network. Flying charter flights for migrant workers is a unique phenomenon in China, especially during the Wuhan lockdown period. The main results are three: (1) private airlines were more active in charter operations during the earlier period, (2) labour charter operation is a newly appeared aviation-government-industry cooperative business model, and (3) there was a spread, change and shift of both charter flows and charter passengers during the four-week period of the study. This case study not only produces useful insights about the important role of charter flights in China during the Covid-19 pandemic period, but also contributes to the theory and practice related to aviation resilience. Also, it contributes to the discussion about aviation policies in China, taking labour charter operation as a window time to predicate future airline dynamics in a more deregulated environment. The results can help airlines, and airports adjust routes, distribute capacity, and adjust layouts for Spring Festival labour transport in normal or post-pandemic times.
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Affiliation(s)
- Chuntao Wu
- School of Tourism, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu 610065, China
| | - Hongmeng Yan
- School of Tourism, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu 610065, China
| | - Wenjing Xue
- School of Tourism, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu 610065, China
| | - Maozhu Liao
- School of Tourism, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu 610065, China
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Marzo RR, Sami W, Alam MZ, Acharya S, Jermsittiparsert K, Songwathana K, Pham NT, Respati T, Faller EM, Baldonado AM, Aung Y, Borkar SM, Essar MY, Shrestha S, Yi S. Hesitancy in COVID-19 vaccine uptake and its associated factors among the general adult population: a cross-sectional study in six Southeast Asian countries. Trop Med Health 2022; 50:4. [PMID: 34983692 PMCID: PMC8727234 DOI: 10.1186/s41182-021-00393-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/20/2021] [Indexed: 01/22/2023] Open
Abstract
Background Vaccines are effective and reliable public health interventions against viral outbreaks and pandemics. However, hesitancy regarding the Coronavirus disease (COVID-19) vaccine is evident worldwide. Therefore, understanding vaccination-related behavior is critical in expanding the vaccine coverage to flatten the infection curve. This study explores the public perception regarding COVID-19 vaccination and identifies factors associated with vaccine hesitancy among the general adult populations in six Southeast Asian countries. Methods Using a snowball sampling approach, we conducted a descriptive cross-sectional study among 5260 participants in Indonesia, Malaysia, Myanmar, Philippines, Thailand, and Vietnam between February and May 2021. Binary logistic regression analysis with a backward conditional approach was applied to identify factors associated with COVID-19 vaccine hesitancy. Results Of the total, 50.6% were female, and the median age was 30 years (range: 15–83 years). The majority of the participants believed that vaccination effectively prevents and controls COVID-19 (81.2%), and 84.0% would accept COVID-19 vaccines when they become available. They agreed that health providers’ advice (83.0%), vaccination convenience (75.6%), and vaccine costs (62.8%) are essential for people to decide whether to accept COVID-19 vaccines. About half (49.3%) expressed their hesitancy to receive the COVID-19 vaccines. After adjustment for other covariates, COVID-19 vaccine hesitancy was significantly associated with age, residential area, education levels, employment status, and family economic status. Participants from Indonesia, Myanmar, Thailand, and Vietnam were significantly more likely to express hesitancy in receiving COVID-19 vaccines than those from Philippines. Conclusions In general, participants in this multi-country study showed their optimistic perception of COVID-19 vaccines’ effectiveness and willingness to receive them. However, about half of them still expressed their hesitancy in getting vaccinated. The hesitation was associated with several socioeconomic factors and varied by country. Therefore, COVID-19 vaccination programs should consider these factors essential for increasing vaccine uptake in the populations.
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Affiliation(s)
- Roy Rillera Marzo
- Department of Community Medicine, International Medical School, Management and Science University, Shah Alam, Selangor, Malaysia.,Department of Community Medicine, Faculty of Medicine, Asia Metropolitan University, Masai, Johor, Malaysia.,Global Public Health, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Subang Jaya, Selangor, Malaysia
| | - Waqas Sami
- Department of Community Medicine and Public Health, College of Medicine, Majmaah University, Almajmaah, 11952, Saudi Arabia.,Azra Naheed Medical College, Superior University, Lahore, 54000, Pakistan
| | - Md Zakiul Alam
- Department of Population Sciences, University of Dhaka, Dhaka, Bangladesh
| | - Swosti Acharya
- Department of Nursing, Nepal Health Research and Innovation Foundation, Lalitpur, Province Bagmati, Nepal
| | | | | | - Nhat Tan Pham
- International University, Ho Chi Minh City, Vietnam.,Vietnam National University Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Titik Respati
- Department of Public Health, Faculty of Medicine and Faculty of Graduate Studies, Universitas Islam Bandung, Bandung, Indonesia
| | - Erwin Martinez Faller
- Department of Pharmacy, Faculty of Pharmacy, San Pedro College, Davao City, Philippines
| | | | - Yadanar Aung
- Medical Statistics Division, Department of Medical Research, Pyin Oo Lwin, Myanmar.,Institute for Population and Social Research, Mahidol University, Bangkok, Thailand
| | | | | | - Sunil Shrestha
- Department of Pharmaceutical and Health Service Research, Nepal Health Research and Innovation Foundation, Lalitpur, Province Bagmati, Nepal
| | - Siyan Yi
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore.,KHANA Center for Population Health Research, Phnom Penh, Cambodia.,Center for Global Health Research, Touro University California, Vallejo, California, USA
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Arjunan A, Robinson J, Baroutaji A, Tuñón-Molina A, Martí M, Serrano-Aroca Á. 3D Printed Cobalt-Chromium-Molybdenum Porous Superalloy with Superior Antiviral Activity. Int J Mol Sci 2021; 22:12721. [PMID: 34884526 PMCID: PMC8657688 DOI: 10.3390/ijms222312721] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 02/04/2023] Open
Abstract
COVID-19 pandemic and associated supply-chain disruptions emphasise the requirement for antimicrobial materials for on-demand manufacturing. Besides aerosol transmission, SARS-CoV-2 is also propagated through contact with virus-contaminated surfaces. As such, the development of effective biofunctional materials that can inactivate SARS-CoV-2 is critical for pandemic preparedness. Such materials will enable the rational development of antiviral devices with prolonged serviceability, reducing the environmental burden of disposable alternatives. This research reveals the novel use of Laser Powder Bed Fusion (LPBF) to 3D print porous Cobalt-Chromium-Molybdenum (Co-Cr-Mo) superalloy with potent antiviral activity (100% viral inactivation in 30 min). The porous material was rationally conceived using a multi-objective surrogate model featuring track thickness (tt) and pore diameter (ϕd) as responses. The regression analysis found the most significant parameters for Co-Cr-Mo track formation to be the interaction effects of scanning rate (Vs) and laser power (Pl) in the order PlVs>Vs>Pl. Contrastively, the pore diameter was found to be primarily driven by the hatch spacing (Sh). The study is the first to demonstrate the superior antiviral properties of 3D printed Co-Cr-Mo superalloy against an enveloped virus used as biosafe viral model of SARS-CoV-2. The material significantly outperforms the viral inactivation time of other broadly used antiviral metals such as copper and silver, as the material's viral inactivation time was from 5 h to 30 min. As such, the study goes beyond the current state-of-the-art in antiviral alloys to provide extra protection to combat the SARS-CoV-2 viral spread. The evolving nature of the COVID-19 pandemic brings new and unpredictable challenges where on-demand 3D printing of antiviral materials can achieve rapid solutions while reducing the environmental impact of disposable devices.
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Affiliation(s)
- Arun Arjunan
- Centre for Engineering Innovation and Research, Additive Manufacturing of Functional Materials (AMFM) Research Group, Faculty of Science and Engineering, Telford Innovation Campus, University of Wolverhampton, Telford TF2 9NT, UK; (J.R.); (A.B.)
| | - John Robinson
- Centre for Engineering Innovation and Research, Additive Manufacturing of Functional Materials (AMFM) Research Group, Faculty of Science and Engineering, Telford Innovation Campus, University of Wolverhampton, Telford TF2 9NT, UK; (J.R.); (A.B.)
- Additive Analytics Ltd., Stirchley Road, Telford TF3 1EB, UK
| | - Ahmad Baroutaji
- Centre for Engineering Innovation and Research, Additive Manufacturing of Functional Materials (AMFM) Research Group, Faculty of Science and Engineering, Telford Innovation Campus, University of Wolverhampton, Telford TF2 9NT, UK; (J.R.); (A.B.)
| | - Alberto Tuñón-Molina
- Biomaterials and Bioengineering Lab, Centro de Investigación Traslacional San Alberto Magno, Universidad Católica de Valencia San Vicente Mártir, c/Guillem de Castro 94, 46001 Valencia, Spain; (A.T.-M.); (M.M.)
| | - Miguel Martí
- Biomaterials and Bioengineering Lab, Centro de Investigación Traslacional San Alberto Magno, Universidad Católica de Valencia San Vicente Mártir, c/Guillem de Castro 94, 46001 Valencia, Spain; (A.T.-M.); (M.M.)
| | - Ángel Serrano-Aroca
- Biomaterials and Bioengineering Lab, Centro de Investigación Traslacional San Alberto Magno, Universidad Católica de Valencia San Vicente Mártir, c/Guillem de Castro 94, 46001 Valencia, Spain; (A.T.-M.); (M.M.)
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