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Article
Publication date: 28 November 2023

Waqar Khan Usafzai, Ioan Pop and Cornelia Revnic

This paper aims to present dual solutions for the two-dimension copper oxide with silver (CuO–Ag) and zinc oxide with silver (ZnO–Ag) hybrid nanofluid flow past a permeable…

Abstract

Purpose

This paper aims to present dual solutions for the two-dimension copper oxide with silver (CuO–Ag) and zinc oxide with silver (ZnO–Ag) hybrid nanofluid flow past a permeable shrinking sheet in a dusty fluid with velocity slip.

Design/methodology/approach

The governing partial differential equations for the two dust particle phases are reduced to the pertinent ordinary differential equations using a similarity transformation. Closed-form analytical solutions for the reduced skin friction and reduced Nusselt number, as well as for the velocity and temperature profiles, were presented, both graphically and in tables, under specific non-dimensional physical parameters such as the suction parameter, Prandtl number, slip parameter and shrinking parameter, which are also presented in both figures and tables.

Findings

The results indicate that for the shrinking flow, the wall skin friction is higher in the dusty fluid when compared with the clear (viscous) fluid. In addition, the effect of the fluid–particle interaction parameter to the fluid phase can be seen more clearly in the shrinking flow. Furthermore, multiple (dual, upper and lower branch solutions) are found for the governing similarity equations and the upper branch solution expanded with higher values of the suction parameter. It can be confirmed that the lower branch solution is unstable.

Practical implications

In practice, the study of the stretching/shrinking flow is crucially important and useful. Both the problems of steady and unsteady flow of a dusty fluid have a wide range of possible applications in practice, such as in the centrifugal separation of particles, sedimentation and underground disposal of radioactive waste materials.

Originality/value

Even though the problem of dusty fluid has been broadly investigated, very limited results can be found for a shrinking sheet. Indeed, this paper has succeeded to obtain analytically dual solutions. The stability analysis can be performed by following many published papers on stretching/shrinking sheets. Finally, the critical values and plotting curves for obtaining single or dual solution are successfully presented.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 12 March 2024

Atifa Kanwal, Ambreen A. Khan, Sadiq M. Sait and R. Ellahi

The particle distribution in a fluid is mostly not homogeneous. The inhomogeneous dispersion of solid particles affects the velocity profile as well as the heat transfer of fluid…

Abstract

Purpose

The particle distribution in a fluid is mostly not homogeneous. The inhomogeneous dispersion of solid particles affects the velocity profile as well as the heat transfer of fluid. This study aims to highlight the effects of varying density of particles in a fluid. The fluid flows through a wavy curved passage under an applied magnetic field. Heat transfer is discussed with variable thermal conductivity.

Design/methodology/approach

The mathematical model of the problem consists of coupled differential equations, simplified using stream functions. The results of the time flow rate for fluid and solid granules have been derived numerically.

Findings

The fluid and dust particle velocity profiles are being presented graphically to analyze the effects of density of solid particles, magnetohydrodynamics, curvature and slip parameters. Heat transfer analysis is also performed for magnetic parameter, density of dust particles, variable thermal conductivity, slip parameter and curvature. As the number of particles in the fluid increases, heat conduction becomes slow through the fluid. Increase in temperature distribution is noticed as variable thermal conductivity parameter grows. The discussion of variable thermal conductivity is of great concern as many biological treatments and optimization of thermal energy storage system’s performance require precise measurement of a heat transfer fluid’s thermal conductivity.

Originality/value

This study of heat transfer with inhomogeneous distribution of the particles in a fluid has not yet been reported.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Open Access
Article
Publication date: 1 January 2024

Bas Becker and Carel Roessingh

Multisited ethnography has primarily been portrayed as a challenge for the following field-worker, with the researcher taking the central role and neglecting research participants…

Abstract

Purpose

Multisited ethnography has primarily been portrayed as a challenge for the following field-worker, with the researcher taking the central role and neglecting research participants also experiencing a multisited nature of their work. The authors argue that literature on multisited ethnography merely discusses multisitedness as a methodological theme. In correspondence, the authors propose to think of multisitedness not just as a methodological theme but also as an empirical theme.

Design/methodology/approach

The authors contend etic and emic perspectives to address multisitedness empirically, which enables researchers to compare and contrast the multisited topic of inquiry in academic “outsider” terms with the etic analysis and considering the perspective of the research participants' multisited experiences using the emic perspective. To show the fruitfulness of discussing multisitedness using the complementary etic and emic analysis, the authors present the example of Mennonite entrepreneurial activities in Belize, a heterogeneous group of migrants that established themselves as successful traders and entrepreneurs.

Findings

Through an etic multisited ethnographic perspective, the authors compare and contrast four communities of Mennonites in terms of their entrepreneurial activities, technology and energy use. Through an emic perspective, the authors demonstrate how Mennonites, while preferring an in-group focus, navigate their multisited entrepreneurial activities, which require interaction with the outside world.

Originality/value

The authors highlight the value of combining etic–emic reflections to acknowledge and include the multisited nature of many social phenomena as experienced by the research participants.

Details

Journal of Organizational Ethnography, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2046-6749

Keywords

Book part
Publication date: 19 January 2024

Richard P. F. Holt

Abstract

Details

Research in the History of Economic Thought and Methodology: Including a Symposium on John Kenneth Galbraith: Economic Structures and Policies for the Twenty-first Century
Type: Book
ISBN: 978-1-80455-931-4

Article
Publication date: 12 January 2024

Hasanuzzaman, Kaustov Chakraborty and Surajit Bag

Sustainability is a major challenge for India’s (Bharat’s) coal mining industry. The government has prioritized sustainable growth in the coal mining industry. It is putting forth…

Abstract

Purpose

Sustainability is a major challenge for India’s (Bharat’s) coal mining industry. The government has prioritized sustainable growth in the coal mining industry. It is putting forth multifaceted economic, environmental and social efforts to accomplish the Sustainable Development Goals (SDGs). This research aims to identify the factors for sustainable improvements in coal mining operations. Secondly, this study examines the intensity of causal relations among the factors. Thirdly, this study examines whether causal relations exist among the factors to be considered for sustainable improvement in coal mining operations. Lastly, the study aims to understand how the factors ensure sustainable improvement in coal mining operations.

Design/methodology/approach

An integrated three-phase methodology was applied to identify the critical factors related to coal mining and explore the contextual relationships among the identified factors. Fifteen critical factors were selected based on the Delphi technique. Subsequently, the fifteen factors were analyzed to determine the contextual and causal relationships using the total interpretive structural modelling (TISM) and DEMATEL methods.

Findings

The study identified “Extraction of Coal and Overburden” as the leading factor for sustainable improvement in coal mining operations, because it directly or indirectly influences the overall mining operation, environmental impact and resource utilization. Hence, strict control measures are necessary in “Extraction of Coal and Overburden” to ensure sustainable coal mining. Conversely, “Health Impact” is the lagging factor as it has very low or no impact on the system. Therefore, it requires fewer control mechanisms. Nevertheless, control measures for the remaining factors must be decided on a priority basis.

Practical implications

The proposed structural model can serve as a framework for enhancing sustainability in India’s (Bharat’s) coal mining operations. This framework can also be applied to other developing nations with similar sustainability concerns, providing valuable guidance for sustainable operations.

Originality/value

The current study highlights the significance of logical links and dependencies between several parameters essential to coal mining sustainability. Furthermore, it leads to the development of a well-defined control sequence that identifies the causal linkages between numerous components needed to achieve real progress towards sustainability.

Details

Benchmarking: An International Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1463-5771

Keywords

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