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1 – 10 of 31Gabriel Węcel, Ziemowit Ostrowski and Pawel Kozołub
The purpose of this paper is to present a new approach of evaluation of the absorption line black body distribution function (ALBDF) for a mixture of gases. Currently published…
Abstract
Purpose
The purpose of this paper is to present a new approach of evaluation of the absorption line black body distribution function (ALBDF) for a mixture of gases. Currently published correlations, which are used to reproduce the ALBDF, treat only single gases.
Design/methodology/approach
A discrete form of the ALBDF is generated using line by line (LBL) calculations. The latest spectroscopic database HITEMP 2010 is used for the generation of the absorption coefficient histogram, which is cumulated later in order to produce a tabulated form of the ALBDF. The proper orthogonal decomposition (POD) statistical method is employed for the reproduction of the ALBDF. Interpolation property of the POD allows to reproduce the ALBDF for arbitrary gas mixture parameters.
Findings
POD proved to possess optimal interpolation properties. Results obtained by using POD are in very good agreement with LBL integration.
Research limitations/implications
One have to be aware that the model generated with the POD method can be used only within the range of parameters used to build the model. The POD does not perform any property extrapolation. The model is limited to a mixture of two gases, namely CO2 and H2O. Expanding the number of gases used in the mixture may lead to a relatively large matrix system, which is difficult to process with the POD approach.
Practical implications
The presented approach can be used to produce absorption coefficients values and their weights, which can be applied in the gas radiative properties description using the weighted sum of gray gas (WSGG) concept. The proposed model can be used with any radiative transfer equation solver which employs the WSGG approach.
Originality/value
For the first time, radiative properties of gas mixtures are reproduced using the POD approach.
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Rahul Yadav, C. Balaji and S.P. Venkateshan
The paper aims to test the spectral line-based weighted sum of gray gases (SLW) method in axisymmetric geometries with particles and high temperature gradients.
Abstract
Purpose
The paper aims to test the spectral line-based weighted sum of gray gases (SLW) method in axisymmetric geometries with particles and high temperature gradients.
Design/methodology/approach
An SLW model is coupled with Trivic’s mean wavelength approach to estimate the radiative heat fluxes at the wall of an enclosure and to the base wall of the rocket exhaust, thereby subsequently studying the effect of concentration variation of the gases and particles in these cases. Radiative transfer equation is solved using modified discrete ordinates method. Anisotropic scattering is modeled using transport approximation.
Findings
Two cases considered show the importance of particle emission and scattering in the rocket plume base heating problems. In cases involving only gases, the concentration of H2O tends to have more impact on the flux values than any other gas.
Originality/value
A full model of gases with particles in an axially varying temperature field is reported. Such cases are very common in practical applications. The present methodology gives more insight and a firm handle on the problem vis-a-vis other traditional techniques.
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This paper seeks to review the literature on methods for solving the radiative transfer equation (RTE) and integrating the radiant energy quantities over the spectrum required to…
Abstract
Purpose
This paper seeks to review the literature on methods for solving the radiative transfer equation (RTE) and integrating the radiant energy quantities over the spectrum required to predict the flow, the flame and the thermal structures in chemically reacting and radiating combustion systems.
Design/methodology/approach
The focus is on methods that are fast and compatible with the numerical algorithms for solving the transport equations using the computational fluid dynamics techniques. In the methods discussed, the interaction of turbulence and radiation is ignored.
Findings
The overview is limited to four methods (differential approximation, discrete ordinates, discrete transfer, and finite volume) for predicting radiative transfer in multidimensional geometries that meet the desired requirements. Greater detail in the radiative transfer model is required to predict the local flame structure and transport quantities than the global (total) radiation heat transfer rate at the walls of the combustion chamber.
Research limitations/implications
The RTE solution methods and integration of radiant energy quantities over the spectrum are assessed for combustion systems containing only the infra‐red radiating gases and gas particle mixtures. For strongly radiating (i.e. highly sooting) and turbulent flows the neglect of turbulence/radiation interaction may not be justified.
Practical implications
Methods of choice for solving the RTE and obtaining total radiant energy quantities for practical combustion devices are discussed.
Originality/value
The paper has identified relevant references that describe methods capable of accounting for radiative transfer to simulate processes arising in combustion systems.
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Wen-Yang Chang and Chih-Ping Tsai
This study aims to investigate the spectral illumination characteristics and geometric features of bicycle parts and proposes an image stitching method for their automatic visual…
Abstract
Purpose
This study aims to investigate the spectral illumination characteristics and geometric features of bicycle parts and proposes an image stitching method for their automatic visual inspection.
Design/methodology/approach
The unrealistic color casts of feature inspection is removed using white balance for global adjustment. The scale-invariant feature transforms (SIFT) is used to extract and detect the image features of image stitching. The Hough transform is used to detect the parameters of a circle for roundness of bicycle parts.
Findings
Results showed that maximum errors of 0°, 10°, 20°, 30°, 40° and 50° for the spectral illumination of white light light-emitting diode arrays with differential shift displacements are 4.4, 4.2, 7.8, 6.8, 8.1 and 3.5 per cent, respectively. The deviation error of image stitching for the stem accessory in x and y coordinates are 2 pixels. The SIFT and RANSAC enable to transform the stem image into local feature coordinates that are invariant to the illumination change.
Originality/value
This study can be applied to many fields of modern industrial manufacturing and provide useful information for automatic inspection and image stitching.
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Ha Minh Hai Thai, Quentin Stevens and Judy Rogers
This paper presents a mixed methodology to map and analyse the spatial connectivity of the everyday pathways that link the doorway of an individual's home–work locations to the…
Abstract
Purpose
This paper presents a mixed methodology to map and analyse the spatial connectivity of the everyday pathways that link the doorway of an individual's home–work locations to the local main commercial street. These pathways include public streets, semi-private lanes, alleys and stairs.
Design/methodology/approach
Pathways within different morphological areas in Hanoi, Vietnam, are used as examples to illustrate the development and application of the methodology. The methodology, adapted from Conzenian, typological, and space syntax methods, combined with observations and interviews, seeks to overcome several identified limitations of each of these approaches for understanding pedestrians' horizontal and vertical movement patterns within urban settings.
Findings
Analytical diagrams of pathways are developed on figure-ground maps of the neighbourhoods and three-dimensional projections of circulation spaces within buildings. Scatter plots are used to analyse the distribution of collected samples according to their business types and distances to local main streets. Field observations and interviews with homeowners revealed the critical influence of the pathways' spatial characteristics on home-based businesses' operations.
Originality/value
The methods developed here are potentially useful for urban morphologists and urban designers in decoding the intricacies of informal urban settings and understanding their socio-economic significance for users.
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Joseph Mbawuni and Simon Gyasi Nimako
This study aims to examine factors affecting the adoption of Islamic banking (IB), which is an innovative and emerging form of banking, in a non-Islamic Sub-Saharan African (SSA…
Abstract
Purpose
This study aims to examine factors affecting the adoption of Islamic banking (IB), which is an innovative and emerging form of banking, in a non-Islamic Sub-Saharan African (SSA) country.
Design/methodology/approach
It used primary data collected from a cross-section of 975 respondents using self-administered structured questionnaire. Empirical data were analysed using SPSS version 16 and partial least squares structural equation modelling (PLS-SEM) for Muslim and non-Muslim groups.
Findings
Consumer attitude, readiness to comply with Sharia law, knowledge, perceived innovativeness and perceived benefits were critical determinants of bank customers’ intention to adopt IB in both Muslim and non-Muslim sub-groups. The least influential factors were perceived religion effect (PRE) and perceived threat of violence (PTV). PTV was not a significant factor to non-Muslims, but it was a significantly negative factor to Muslims’ intentions to adopt IB. PRE has a positive influence on Muslims’ intention to adopt IB, but it has a negative effective on non-Muslims’ adoption intentions.
Research limitations/implications
This study is limited to only bank customers in Ghana. Moreover, service quality factors were not included in the research model because IB is yet to be given full-fledged operational license in Ghana. Future research should extend the study to other emerging countries to improve the generalizability of the findings.
Practical implications
Policymakers are encouraged to develop stakeholder-oriented strategies to promote effective consumer education in IB. Also, IB institution should endeavour to develop innovative financial products that are Sharia-compliant and economically beneficial to individual and business needs of bank customers. Moreover, policymakers and management of IB institutions should ensure effect governance structures to guide IB operations.
Originality/value
This study provides initial structural equation modelling of determinants of IB adoption in emerging countries and provides empirical evidence on the spread of IB in non-Islamic SSA, which is an under-researched area. It is the first study to empirically report on the influence of PTV, readiness to compliance Sharia law and perceived innovativeness of IB on intentions to adopt IB in non-Islamic SSA context.
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Xiao Zhou Liu, Shuang Ling and Ying Liu
This study aims to empirically examine the relationship between Internet use and personal privacy risk perceptions, the mediating effect of trust and the moderating effect of…
Abstract
Purpose
This study aims to empirically examine the relationship between Internet use and personal privacy risk perceptions, the mediating effect of trust and the moderating effect of satisfaction on that relationship, which is exactly conducive to the practice of personal information protection.
Design/methodology/approach
A moderated mediation model will be employed to test the hypothesized relationships using the 2017 Chinese Society Survey data.
Findings
The authors find that Internet use positively relates to citizens' risk perceptions toward privacy security, and trust partially mediates the relationship between Internet use and privacy risk perception. In addition, the analysis of moderating effects showed that satisfaction with social life significantly enhances the negative impact on individuals' privacy risk perceptions of interpersonal trust. The positively moderating effect of satisfaction with local governments' work mainly reveals the relationship between interpersonal trust (or institutional trust) and citizens' privacy risk perception. Moreover, satisfaction with Internet platforms positively moderates the relationship between consumer trust and privacy risk perception.
Originality/value
This article contributes to the social risk amplification framework by applying it to the personal privacy information protection field, which was rarely discussed before. It also enriches privacy research by identifying the internal mechanism of how Internet use influences citizens' risk perceptions towards privacy information leakage.
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Mohamed Al‐Hussein, Sabah Alkass and Osama Moselhi
This paper presents a newly developed algorithm for selecting and locating mobile cranes on construction sites. The algorithm is incorporated into a computer system that…
Abstract
This paper presents a newly developed algorithm for selecting and locating mobile cranes on construction sites. The algorithm is incorporated into a computer system that integrates a selection module and three databases, dedicated respectively, for cranes, rigging equipment, and projects’ information. This paper focuses primarily on the selection module and its algorithm to support an efficient search for most suitable crane configurations and their associated lift settings. Data pertinent to crane lift configurations and settings are retrieved from the databases and processed to determine the near optimum selection of a crane configuration. The developed selection module features powerful graphics capabilities and a practical user‐friendly interface, designed to facilitate the considerations of user imposed lift and site constraints. The selection algorithm has been implemented within the crane selection module using MS‐Visual Basic programming language. A case example is presented in order to demonstrate the use of the developed selection module and to illustrate its essential features.
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