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To ensure the safety of aircraft fuel tanks, the FAA issued an airworthiness clause (25.981(b)) suggesting that the risk of combustion and explosion be reduced by installing a Flammability Reduction Means or an Ignition Mitigation Means. The airflow distribution method has a significant effect on the inerting performance. Therefore, this study aims to determine an optimum airflow distribution method of the inerting system.

This paper establishes the calculation model of the oxygen concentration in the ullage of a multi-bay fuel tank, calculates the oxygen concentration in the ullage of an aircraft tank in single-flow and dual-flow modes under series and parallel ventilation methods and analyses the inerting performance of the tank under different airflow distribution methods.

The results show that: (1) the bleed flow rate required to achieve whole process inerting of multi-bay fuel tank in dual-flow mode is lower than that in single-flow mode; (2) under the parallel ventilation method, the decrease of oxygen concentration and the uniformity of each bay are better than that in the series ventilation method; (3) dual-flow mode staged ventilation method can be used to achieve the whole process inerting of the tanks under the minimum engine bleed consumption.

The novelty of this paper is to analyze and optimize the airflow distribution method of the inerting system under the whole flight envelope to minimize the engine bleed consumption.

This study aims to explore the impact of blockchain announcements on enterprises' stock market value.

Based on resource-based theory, this study constructs a complete framework of the impact mechanism of blockchain announcements on the stock price of the announcing firm using the data of 143 blockchain announcements. An event study methodology is used in this research, and the market model, market-adjusted model and Carhart four-factor model are used to estimate stock abnormal returns after the blockchain announcement; and the cross-sectional regression model is used to test the influencing factors.

Blockchain announcements elicit a significantly positive market reaction on the release day. Compared to announcements not pertaining to technical innovation, blockchain technical innovation announcements exhibit a more positive market reaction towards the announcing companies. Strategic-level announcements exhibit a more positive market reaction than operational-level announcements. Enterprise characteristics, such as enterprise-scale and enterprise innovation ability, do not affect stock market reactions to blockchain announcements.

The findings reveal the economic value of conducting blockchain activities in the Chinese stock market. Findings of this study can help managers understand the value of implementing blockchain activities in a different market environment and guide them on how to improve the market value of their enterprises through the active implementation of blockchain activities.

To the best of the authors’ knowledge, this is the first event study to focus solely on the value of pure blockchain announcements in an emerging market. This study considers multiple resource and capability factors that would influence blockchain technology adoption, improve the current understanding of how blockchain announcements affect corporate stock prices and provide directions for future comparative studies of market reactions to blockchain announcements in different stock markets.

The purpose of this study is to establish a method for accurately extracting torch and seam features. This will improve the quality of narrow gap welding. An adaptive deflection correction system based on passive light vision sensors was designed using the Halcon software from MVtec Germany as a platform.

This paper proposes an adaptive correction system for welding guns and seams divided into image calibration and feature extraction. In the image calibration method, the field of view distortion because of the position of the camera is resolved using image calibration techniques. In the feature extraction method, clear features of the weld gun and weld seam are accurately extracted after processing using algorithms such as impact filtering, subpixel (XLD), Gaussian Laplacian and sense region for the weld gun and weld seam. The gun and weld seam centers are accurately fitted using least squares. After calculating the deviation values, the error values are monitored, and error correction is achieved by programmable logic controller (PLC) control. Finally, experimental verification and analysis of the tracking errors are carried out.

The results show that the system achieves great results in dealing with camera aberrations. Weld gun features can be effectively and accurately identified. The difference between a scratch and a weld is effectively distinguished. The system accurately detects the center features of the torch and weld and controls the correction error to within 0.3mm.

An adaptive correction system based on a passive light vision sensor is designed which corrects the field-of-view distortion caused by the camera’s position deviation. Differences in features between scratches and welds are distinguished, and image features are effectively extracted. The final system weld error is controlled to 0.3 mm.

This study empirically examines the impact of announcements on supply chain strategic collaboration (SCSC) on companies' shareholder value.

This study analyzes changes in shareholder value of companies listed in China based on data of 208 SCSC announcements. The signaling theory is applied to determine correlation among SCSC announcements and the market. An event study is used to estimate the stock market reaction to SCSC announcements. The common market model estimates stock abnormal returns after the event. The least squares method and regression model calculate the model parameter value.

There is a positive and statistically significant relationship between SCSC announcement and shareholder value. Market reaction to product development collaboration is significantly higher than to technology-sharing collaboration, market collaboration, and other SCSC types. The market reacts more positively to suppliers and companies with greater supply chain control power than to buyers and companies with lower control power. Announcements from the service supply chain can lead to stronger market reactions than those from manufacturing supply chains.

The findings provide a systematic assessment of how SCSC announcements contribute to firms' shareholder value. The result provides a benchmark of value promotion that can be expected from SCSC announcements.

This study fills the research gap that using secondary data to assess changes in companies’ shareholder value caused by SCSC announcements and firstly examines these changes by constructing the signaler–signal–receiver progress based on signaling theory. The research results provide a new reference and inspiration for deeper understanding of the impact mechanism of SCSC. Furthermore, this study contributes to the development of the signaling theory using an empirical study in an emerging market, China.

This study explores the influencing factors affecting smart supply chain innovation (SSCI) performance of commodity distribution enterprises, and proposes the corresponding framework from the perspective of the application of technology to improve the SSCI performance and make up the research gap in this field.

A multi-case study method is adopted in this study. Four distribution commodity distribution enterprises A, B, C and D in China are chosen as case enterprises. The interviews with senior management team members are used to collect data. The combination of open coding and axial coding are used to process the data. By testing the reliability and validity, the theoretical framework is summarized.

First, we find that the technology application cost inhibits SSCI and that the level of technology suitable for enterprise development will promote SSCI. Second, SSCI in structure, management and services can improve the performance and innovation ability of enterprises. Third, the quality of multi-channel integration and degree of customization around customer demand can significantly modify the above effects.

Compared with previous studies, this study reveals for the first time the correlation between the SSCI performance and technology application, SSCI in structure, management and service, providing new ideas for relevant researches on SSCI, and providing new theoretical support for managers' decision-making related to SSCI.

To reduce the flammability exposure assessment time and meet the requirements of airworthiness regulations of transport aircraft, inerting system has become the standard configuration of modern civil aircraft. Therefore, airworthiness regulations put forward definite quantitative index requirements for the safety of inerting system, and to obtain the quantitative data of the safety of inerting system, it is necessary to solve the calculation method. As one of the quantitative/qualitative evaluation techniques for system safety, fault tree analysis is recognized by international airworthiness organizations and national airworthiness certification agencies. When fault tree analysis technology is applied to quantitative analysis of the safety of inerted system, there are still some problems, such as heavy margin of constructing fault tree, great difficulty, high requirement for analysts and poor accuracy of solving when there are too many minimum cut sets. However, based on tens of thousands of flight simulation tests, Monte Carlo random number generation method can solve this problem.

In this paper, the fault tree of airborne inerting system is established, and the top event is airborne inerting system losing air separation function. Monte Carlo method based on random number generation is used to carry out system security analysis. The reliability of this method is verified.

The static fault tree analysis method based on Monte Carlo random number generation can not only solve the problem of quantitative analysis of inerting system, but can also avoid the defects of complicated solution and inaccurate solution caused by the large number of minimum cut sets, and its calculation results have good reliability.

The research results of this paper can be used as supporting evidence for airworthiness compliance of airborne inerting system.

The research results of this paper can provide practical guidance for the current civil airworthiness certification work.

The purpose of this study is to improve the performance of hollow fiber membrane and improve the separation efficiency.

By establishing a mathematical model of hollow fiber membrane gas separation, the influences of parameters such as pressure difference between the inside and outside of the filament, initial oxygen concentration of intake air, intake air flow rate and back pressure outside the filament on the polarization coefficient were analyzed, so as to explore the degree of influence of operating parameters on the concentration polarization, and put forward a technical scheme to reduce the concentration polarization.

Factors such as pressure difference between the inside and outside of the filament, initial oxygen concentration of intake air, intake air flow rate and back pressure outside the filament have a certain effect on the polarization coefficient. Among them, the polarization coefficient is positively correlated with pressure difference inside and outside the filament, initial oxygen concentration of intake air and back pressure outside the filament, and is negatively correlated with intake air flow.

Negative pressure suction on the permeation side can be used to increase the membrane permeation flow rate and reduce the concentration polarization.

The influence of concentration polarization on membrane performance is reduced by controlling various factors.

The purpose of this study is to examine the impact of the implementation of supply chain strategic collaboration (SCSC) on companies’ operating performance.

Based on 181 SCSC announcements of listed companies in China, this study analyzes changes in the operating performance of the sample companies in the 20 quarters after the announcement. The changes in different operating performance metrics for the sample firms are compared against their metrics before the announcement. This study uses a self-control model based on historical performance and uses a combination of adjustment percentage changes and adjustment level changes to measure performance changes.

SCSC helps to improve firm operating performance, although this effect is only evident after two years. Companies that collaborate on product development have better performance improvements than do companies that implement market collaboration. The operating performance of buyer companies is better than that of supplier companies. Finally, strategic collaboration in the service supply chain improves performance more than that in the manufacturing supply chain.

The finding that company performance varies in different situations can help managers better understand and manage SCSC.

This study newly uses secondary data to assess changes in companies’ operating performance brought about by the implementation of SCSC.

This paper aims to improve the previous fuel scrubbing model and find out the relationship between bubble diameter and scrubbing efficiency (ƞ).

A fuel tank scrubbing test bench was established to verify the accuracy of this model. Ullage and dissolved oxygen concentration were measured, and images of bubble size and distribution were collected and analyzed using image analysis software.

The bubble diameter has a great influence on ullage and dissolved oxygen concentration during the fuel scrubbing process. The scrubbing efficiency (ƞ) has an exponential relationship with bubble diameter and decreases rapidly as the bubble diameter increases.

The variation of the ullage and dissolved oxygen concentration predicted by this model is more accurate than that of the previous model. In addition, the study of bubble size can provide a guidance for the design of fuel scrubber.

This study not only improves the previous fuel scrubbing model but also develops a method to calculate scrubbing efficiency (ƞ) based on bubble diameter. In addition, a series of tests and analyses were conducted, including numerical calculation, experiment and image analysis.

The purpose of this study is to measure the mass diffusion coefficient of nitrogen in jet fuel using digital holography interferometry for cost-effective designing and modeling of the aircraft tank inerting system.

The mass diffusion coefficients of N₂ in RP-3 and RP-5 jet fuels were measured by digital holography interferometry at temperatures ranging from 278.15 to 343.15 K. The Arrhenius equation is used to adequately describe the relationship between mass diffusion coefficients and temperature. The viscosities of RP-3 and RP-5 jet fuels were also measured to examine the accuracy of the Stokes–Einstein model in calculating mass diffusion coefficients.

As temperature increases from 278.15 to 343.15 K, the mass diffusion coefficients increase 4.23-fold for N₂ in RP-3 jet fuel and 5.13-fold for N₂ in RP-5 jet fuel. The value of Dµ/T is not constant as the Stokes–Einstein equation expressed, but is a weak linear function of temperature.

A more accurate diffusion model is proposed by fitting the measured Dµ/T with the temperature and calculating the mass diffusion coefficients of N₂ in RP-3 and RP-5 jet fuels within 10 per cent relative deviation.

A measurement system for mass diffusion coefficients of N₂ in RP-3 and RP-5 jet fuels was constructed based on the digital holography interferometry. The mass diffusion coefficient can be expressed by a uniform polynomial function of temperature and viscosity.