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Article
Publication date: 19 November 2018

Lei Shao, Shiyu Feng, Chaoyue Li, Weihua Liu and Xuying Huang

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

Abstract

Purpose

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

Design/methodology/approach

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.

Findings

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.

Practical implications

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.

Originality/value

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.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 20 June 2019

Shiyu Feng, Chaoyue Li, Xiaotian Peng, Lei Shao and Weihua Liu

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Practical implications

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.

Originality/value

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.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 8
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 8 January 2019

Chaoyue Li, Shiyu Feng, Lei Shao, Jun Pan and Weihua Liu

This study aims to get the essential data of the solubility and diffusion coefficient of gas in jet fuel for appropriately designing a kind of on-board inert gas generation system.

Abstract

Purpose

This study aims to get the essential data of the solubility and diffusion coefficient of gas in jet fuel for appropriately designing a kind of on-board inert gas generation system.

Design/methodology/approach

A test apparatus based on pressure–decay method was constructed to measure solubility and diffusion coefficient of gas in liquid. The test apparatus and method were verified via measurement of solubility and diffusion of CO2 in the pure water.

Findings

The solubility of CO2 and O2 in RP-3 jet fuel with the temperature from 253 to 313 K under three various pressures were measured and compared with theoretical value calculated by a relative density method provided in the standard of ASTM D2780-92, and the deviation is within 10 per cent. The diffusion coefficients of CO2 and O2 in RP-3 jet fuel are determined by monitoring the gas pressure in a hermetic cell versus time with the temperature from 253 to 333 K. The measured diffusivity-temperature relation can be well fitted through the Arrhenius equation for engineering applications. The obtained correlation can be used to predict the diffusion coefficient of CO2 and O2 in RP-3 jet fuel under a wide temperature range.

Practical implications

The semi-empirical correlation of solubility and diffusion coefficient in RP-3 jet fuel obtained from the experimental data could be used to support the design of an inert gas generation system.

Originality/value

There are no essential data of solubility and diffusion of CO2 and O2 in RP-3 jet fuel; therefore, it is fatal if the quantity and rate of mass transfer of CO2 and O2 in RP-3 jet fuel must be assessed, e.g. during the design of green on-board inert gas generation system.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 2 July 2020

Eun-Jee Kim and Sunyoung Park

This study examined the relationships among transformational leadership, organizational climate, employees' knowledge-sharing behavior and organizational learning.

Abstract

Purpose

This study examined the relationships among transformational leadership, organizational climate, employees' knowledge-sharing behavior and organizational learning.

Design/methodology/approach

Data were collected from 282 responses from multiple companies in South Korea. Descriptive statistics and correlations were provided. The structural equation modeling was primarily used to test the proposed hypotheses and model comparisons.

Findings

The results indicated direct effects of transformational leadership on organizational climate, knowledge-sharing and organizational learning. In addition, organizational climate was positively related to knowledge-sharing behavior. Finally, knowledge-sharing behavior was found to affect organizational learning and to be a mediator in linking transformational leadership and organizational learning.

Research limitations/implications

This study contributes to the literature on the role of leader’s support to enhance employees' outcomes related to knowledge and learning. By investing different antecedents of organizational learning, this study will help scholars and professionals pay more attention to organizational learning, its process and outcomes, which can promote organizational effectiveness and next outcomes from organizational learning.

Practical implications

Organizations need to pay continuous attention to maintaining and strengthening employees’ knowledge-sharing behavior and learning, which is positively influenced by organizational efforts (i.e. leader’s support and supportive organizational climate).

Originality/value

The significance of this study is that the findings add to the academic work on organizational learning by empirically examining how leadership and organizational climate factors influence knowledge and learning outcomes and through which mechanisms.

Details

Leadership & Organization Development Journal, vol. 41 no. 6
Type: Research Article
ISSN: 0143-7739

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Article
Publication date: 16 May 2019

Bourahla Kheireddine, Belli Zoubida and Hacib Tarik

This study aims to improve the bat algorithm (BA) performance for solving optimization problems in electrical engineering.

Abstract

Purpose

This study aims to improve the bat algorithm (BA) performance for solving optimization problems in electrical engineering.

Design/methodology/approach

For this task, two strategies were investigated. The first one is based on including the crossover technique into classical BA, in the same manner as in the genetic algorithm method. Therefore, the newly generated version of BA is called the crossover–bat algorithm (C-BA). In the second strategy, a hybridization of the BA with the Nelder–Mead (NM) simplex method was performed; it gives the NM-BA algorithm.

Findings

First, the proposed strategies were applied to solve a set of two standard benchmark problems; then, they were applied to solve the TEAM workshop problem 25, where an electromagnetic field was computed by use of the 2D non-linear finite element method. Both optimization algorithms and finite element computation tool were implemented under MATLAB.

Originality/value

The two proposed optimization strategies, C-BA and NM-BA, have allowed good improvements of classical BA, generally known for its poor solution quality and slow convergence rate.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 38 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 28 October 2014

Zhang Huaiqing, Nie Xin, Chen Yu and Fu Zhihong

The purpose of this paper is to solve the interface discontinuities in radial basis function (RBF) method for multi-medium boundary value problems (BVPs). The…

Abstract

Purpose

The purpose of this paper is to solve the interface discontinuities in radial basis function (RBF) method for multi-medium boundary value problems (BVPs). The discontinuity of the solution derivatives is not easily handled with RBF method because of infinitely smoothness.

Design/methodology/approach

The essence of solving BVP is to construct the continuous potential function surfaces. Hence, from constructing surface aspect, this paper proposed and compared the global and subzone schemes for RBF method. Their implementation schemes and mathematic models can then be derived. Numerical experiments and comparison are carried out for electric and magnetic field calculation.

Findings

In the numerical experiments, the subzone scheme has shown its significant advantageous, it can approximate not only the potential function but also its derivative on interface boundary with high accuracy. So the physical characteristics of discontinuities on the interface can be revealed clearly. The overall precision is significantly improved.

Originality/value

This paper proposed an effective subzone scheme for RBF method in multi-medium BVP. It is an improvement for RBF method based on its domain decomposition idea. And it is also a candidate for solving complex BVP.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33 no. 6
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 7 September 2012

Ali Zamani, Ahmad Mirabadi and Felix Schmid

In writing this paper, the authors investigated the use of electromagnetic sensors in axle counter applications by means of train wheel detection. The purpose of this…

Abstract

Purpose

In writing this paper, the authors investigated the use of electromagnetic sensors in axle counter applications by means of train wheel detection. The purpose of this paper is to improve the detection capability of train wheel detectors, by installing them in the optimal orientation and position, using finite element modeling (FEM) in combination with metamodeling techniques. The authors compare three common metamodeling techniques for the special case of wheel detector orientation: response surface methodology; multivariate adaptive regression splines; and kriging.

Design/methodology/approach

After analyzing the effective parameters of a train wheel detector, an appropriate method for decreasing the system susceptibility to electromagnetic noises is presented.

Findings

The results were validated using a laboratory‐based system and also the results of field tests carried out on the Iranian railway network. The results of the study suggest that the FEM method and a metamodeling technique can reduce the computational efforts and processing time.

Originality/value

In this paper, combination of FEM and metamodeling approaches are used to optimize the railway axle counter coils orientation, which is more insusceptible to electromagnetic noise than initial arrangement used by some signallers.

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Article
Publication date: 13 September 2019

Hui Lei, Nguyen Khoi Do and Phong Ba Le

The purpose of this paper is to investigate the correlation between ethical leadership (EL), collaborative culture (CC), knowledge-centered culture and employees…

Abstract

Purpose

The purpose of this paper is to investigate the correlation between ethical leadership (EL), collaborative culture (CC), knowledge-centered culture and employees’ behaviors toward knowledge sharing (KS) in Chinese firms.

Design/methodology/approach

The paper used structural equation modeling to examine the level of how EL, CC and knowledge-centered culture impact on tacit and explicit KS of employees via the data collected from 319 participants in 51 Chinese firms.

Findings

The research findings show collaborative and knowledge-centered culture mediates the relationship between EL and employees’ KS behaviors. It highlights the necessity of practicing EL style to develop a positive climate aimed at positively improving tacit and explicit KS of employees.

Research limitations/implications

Future studies should focus on investigating the relationship between EL, CC and knowledge management process or the other variables to explore and maximize their potential and benefits toward key organizational outcomes.

Practical implications

This paper offers leaders a deeper understanding of the effective pathways to build positive climates for fostering employees’ tacit and explicit KS.

Originality/value

This paper is unique in the attempts to increase the understanding of moral lens by which EL might successfully arouse a positive organizational culture and foster KS behaviors in their firms.

Details

Journal of Knowledge Management, vol. 23 no. 8
Type: Research Article
ISSN: 1367-3270

Keywords

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Article
Publication date: 20 January 2021

Hui Lei, Linnan Gui and Phong Ba Le

Given the important role of frugal innovation for firms in the developing and emerging countries, the purpose of this paper is to investigate the effect of…

Abstract

Purpose

Given the important role of frugal innovation for firms in the developing and emerging countries, the purpose of this paper is to investigate the effect of transformational leadership (TL) on frugal innovation through the mediating roles of tacit and explicit knowledge sharing.

Design/methodology/approach

The paper used a quantitative research method and structural equation modeling to test the relationship among the latent factors based on a sample of 339 participants from 120 Vietnamese firms.

Findings

Findings reveal the significant impacts of TL on aspects of frugal innovation, namely, frugal functionality, frugal cost and frugal ecosystem. Moreover, the paper highlights the mediating roles of tacit and explicit knowledge sharing (KS) in the relationship between TL and frugal innovation in terms of frugal functionality and frugal cost.

Research limitations/implications

To bring a deeper understanding of the benefits and important role of knowledge resources, future research should investigate the potential mediating mechanisms of knowledge management processes in the relationship between specific leadership styles and frugal innovation.

Practical implications

The paper provides a valuable understanding and novel approach for managers and directors of firms in developing and emerging countries to improve their firms’ frugal innovation capability through leadership practice and knowledge resources.

Originality/value

This study contributes to bridging research gaps in the literature and advances the insights of how TL directly and indirectly fosters frugal innovation via mediating roles of tacit and explicit KS.

Details

Journal of Knowledge Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1367-3270

Keywords

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Article
Publication date: 28 April 2020

Phong Ba Le, Hui Lei, Thanh Trung Le, Jiexi Gong and Anh ThiLan Ha

This paper aims to examine the influence of collaborative culture on employee’s knowledge sharing and how it associated with radical and incremental innovation in Chinese firms.

Abstract

Purpose

This paper aims to examine the influence of collaborative culture on employee’s knowledge sharing and how it associated with radical and incremental innovation in Chinese firms.

Design/methodology/approach

This study used the quantitative approach and structure equation model to test hypotheses with data collected by questionnaire from 371 participants in 68 Chinese firms.

Findings

The research findings indicated that collaborative culture positively fosters the KS behaviors of employees for radical and incremental innovation. The findings confirm the mediating role of tacit and explicit knowledge sharing and reveal that collaborative culture has a significant impact on incremental innovation, whereas knowledge sharing behaviors have greater impacts on radical and incremental innovation.

Research limitations/implications

Future research should investigate the impact of collaborative culture on innovation under moderating effects of ownership form or mediating roles of behavioral variables to have better understanding on the relationship among them.

Practical implications

This study offers leaders a deeper understanding of the necessary factors and new pathways to stimulate employees’ tacit and explicit knowledge sharing for innovation.

Originality/value

The paper has significant contributed to theoretical and practical initiatives on the theory of innovation which highlighted the crucial role of collaborative culture in facilitating a positive climate for knowledge sharing and innovation.

Details

Chinese Management Studies, vol. 14 no. 4
Type: Research Article
ISSN: 1750-614X

Keywords

1 – 10 of 192