Nirmal Kumar Acharya, Young Dai Lee and Hae Man Im
The purpose of this article is to identify and explore pertinent conflicting factors in construction projects; which would be helpful for project planners and implementers in…
Abstract
Purpose
The purpose of this article is to identify and explore pertinent conflicting factors in construction projects; which would be helpful for project planners and implementers in assessing and taking proactive measures for reducing the adverse effect of conflict.
Design/methodology/approach
To achieve the study objectives, a 43‐item questionnaire survey in a five‐point Likert scale was carried out to collect professionals' experience on conflicting activities in Korean construction projects. Responses from 124 professionals working for owners, consultants and contractors were analyzed. Furthermore, ten face‐to face interviews were also carried out to ratify the findings from the field survey. Later, analytical hierarchical process method was employed to find out the importance weighting as well as responsible party for the perceived conflicts.
Findings
This study has found out six critical construction conflicting factors pertinent in Korean context. These factors with importance weighting are: differing site condition (24.1 percent), public interruption (22.5 percent), differences in change order evaluation (21 percent), design errors (17.1 percent), excessive contract quantities variation (8.2) and double meaning of specifications (7.1 percent). The study has revealed that owner (35.6 percent) and consultant (34.18 percent) are mostly responsible parties for conflicts in construction projects.
Originality/value
As the previous researches have been indicating increase in conflicts in construction field, this paper is very topical at the moment. This work has tried to explore the underlying problems of the construction field. The study provides field level experiences from which the inexperience construction site professionals could learn the instances of conflicts and not repeat the mistakes in their projects.
Details
Keywords
Aniket Halder, Arabdha Bhattacharya, Nirmalendu Biswas, Nirmal K. Manna and Dipak Kumar Mandal
The purpose of this study is to carry out a comprehensive analysis of magneto-hydrodynamics (MHD), nanofluidic flow dynamics and heat transfer as well as thermodynamic…
Abstract
Purpose
The purpose of this study is to carry out a comprehensive analysis of magneto-hydrodynamics (MHD), nanofluidic flow dynamics and heat transfer as well as thermodynamic irreversibility, within a novel butterfly-shaped cavity. Gaining a thorough understanding of these phenomena will help to facilitate the design and optimization of thermal systems with complex geometries under magnetic fields in diverse applications.
Design/methodology/approach
To achieve the objective, the finite element method is used to solve the governing equations of the problem. The effects of various controlling parameters such as butterfly-shaped triangle vertex angle (T), Rayleigh number (Ra), Hartmann number (Ha) and magnetic field inclination angle (γ ) on the hydrothermal performance are analyzed meticulously. By investigating the effects of these parameters, the authors contribute to the existing knowledge by shedding light on their influence on heat and fluid transport within butterfly-shaped cavities.
Findings
The major findings of this study reveal that the geometrical shape significantly alters fluid motion, heat transfer and irreversibility production. Maximum heat transfer, as well as entropy generation, occurs when the Rayleigh number reaches its maximum, the Hartmann number is minimized and the angle of the magnetic field is set to 30° or 150°, while the butterfly wings angle or vertex angle is kept at a maximum of 120°. The intensity of the magnetic field significantly controls the heat flow dynamics, with higher magnetic field strength causing a reduction in the flow strength as well as heat transfer. This configuration optimizes the heat transfer characteristics in the system.
Research limitations/implications
Further research can be expanded on this study by examining thermal performance under different curvature effects, orientations, boundary conditions and additional factors. This can be accomplished through numerical simulations or experimental investigations under various multiphysical scenarios.
Practical implications
The geometric configurations explored in this research have practical applications in various engineering fields, including heat exchangers, crystallization processes, microelectronic devices, energy storage systems, mixing processes, food processing, air-conditioning, filtration and more.
Originality/value
This study brings value by exploring a novel geometric configuration comprising the nanofluidic flow, and MHD effect, providing insights and potential innovations in the field of thermal fluid dynamics. The findings contribute a lot toward maximizing thermal performance in diverse fields of applications. The comparison of different hydrothermal behavior and thermodynamic entropy production under the varying geometric configuration adds novelty to this study.
Details
Keywords
Nirmalendu Biswas, Nirmal K. Manna, Dipak Kumar Mandal and Rama Subba Reddy Gorla
The purpose of this study is to address magnetohydrodynamic (MHD) bioconvection caused by the swimming of oxytactic microorganisms in a linearly heated square cavity filled with…
Abstract
Purpose
The purpose of this study is to address magnetohydrodynamic (MHD) bioconvection caused by the swimming of oxytactic microorganisms in a linearly heated square cavity filled with porous media and Cu–water nanofluid. The effects of different multiphysical aspects are demonstrated using local distributions as well as global quantities for fluid flow, temperature, oxygen concentration and microorganisms population.
Design/methodology/approach
The coupled transport equations are converted into the nondimensional partial differential equations, which are solved numerically using a finite volume-based computing code. The flow of Cu–water nanofluid through the pores of porous media is formulated following the Brinkman–Forchheimer–Darcy model. The swimming of oxytactic microorganisms is handled following a continuum model.
Findings
The analysis of transport phenomena of bioconvection is performed in a linearly heated porous enclosure containing Cu–water nanofluid and oxytactic microorganisms under the influence of magnetic fields. The application of such a system could have potential impacts in diverse fields of engineering and science. The results show that the flow and temperature distribution along with the isoconcentrations of oxygen and microorganisms is markedly affected by the involved governing parameters.
Research limitations/implications
Similar study of bioconvection could be extended further considering thermal radiation, chemical attraction, gravity and light.
Practical implications
The outcomes of this investigation could be used in diverse fields of multiphysical applications, such as in food industries, chemical processing equipment, fuel cell technology and enhanced oil recovery.
Originality/value
The insight of the linear heating profile reveals a special attribute of simultaneous heating and cooling zones along the heated side. With such an interesting feature, the MHD bioconvection of oxytactic microorganisms in nanofluid-filled porous substance is not reported so far.
Details
Keywords
Nirmalendu Biswas, Aparesh Datta, Nirmal K. Manna, Dipak Kumar Mandal and Rama Subba Reddy Gorla
This study aims to explore magnetohydrodynamic (MHD) thermo-bioconvection of oxytactic microorganisms in multi-physical directions addressing thermal gradient, lid motion, porous…
Abstract
Purpose
This study aims to explore magnetohydrodynamic (MHD) thermo-bioconvection of oxytactic microorganisms in multi-physical directions addressing thermal gradient, lid motion, porous substance and magnetic field collectively using a typical differentially heated two-sided lid-driven cavity. The consequences of a range of pertinent parameters on the flow structure, temperature, oxygen isoconcentration and microorganisms’ isoconcentration are examined and explained in great detail.
Design/methodology/approach
Two-dimensional governing equations in a two-sided lid-driven porous cavity heated differentially and packed with oxytactic microorganisms under the influence of the magnetic field are solved numerically using the finite volume method-based computational fluid dynamics code. The evolved flow physics is analyzed assuming a steady laminar incompressible Newtonian flow within the validity of the Boussinesq approximation. The transport of oxytactic microorganisms is formulated by augmenting the continuum model.
Findings
The mechanisms involved with MHD-mixed thermo-bioconvection could have potential benefits for industrial exploitation. The distributions of fluid flow, temperature, oxygen and motile microorganisms are markedly modified with the change of convection regime. Both speed and direction of the translating walls significantly influence the concentration of the motile microorganisms. The concentration of oxygen and motile microorganisms is found to be higher at the upper portion of the cavity. The overall patterns of the fluid flow, temperature and the oxygen and microorganism distributions are markedly affected by the increase of magnetic field strength.
Research limitations/implications
The concept of the present study could be extended to other areas of bioconvection in the presence of gravity, light or chemical attraction.
Practical implications
The findings of the present study could be used to multi-physical applications like biomicrosystems, pollutant dispersion in aquifers, chemical catalytic converters, geothermal energy usage, petroleum oil reservoirs, enhanced oil recovery, fuel cells, thermal energy storage and others.
Originality/value
The MHD-mixed thermo-bioconvection of oxytactic microorganisms is investigated under different parametric conditions. The effect of pertinent parameters on the heat and mass transfers are examined using the Nusselt number and Sherwood number.
Details
Keywords
Sobhan Pandit, Milan K. Mondal, Dipankar Sanyal, Nirmal K. Manna, Nirmalendu Biswas and Dipak Kumar Mandal
This study aims to undertake a comprehensive examination of heat transfer by convection in porous systems with top and bottom walls insulated and differently heated vertical walls…
Abstract
Purpose
This study aims to undertake a comprehensive examination of heat transfer by convection in porous systems with top and bottom walls insulated and differently heated vertical walls under a magnetic field. For a specific nanofluid, the study aims to bring out the effects of different segmental heating arrangements.
Design/methodology/approach
An existing in-house code based on the finite volume method has provided the numerical solution of the coupled nondimensional transport equations. Following a validation study, different explorations include the variations of Darcy–Rayleigh number (Ram = 10–104), Darcy number (Da = 10–5–10–1) segmented arrangements of heaters of identical total length, porosity index (ε = 0.1–1) and aspect ratio of the cavity (AR = 0.25–2) under Hartmann number (Ha = 10–70) and volume fraction of φ = 0.1% for the nanoparticles. In the analysis, there are major roles of the streamlines, isotherms and heatlines on the vertical mid-plane of the cavity and the profiles of the flow velocity and temperature on the central line of the section.
Findings
The finding of a monotonic rise in the heat transfer rate with an increase in Ram from 10 to 104 has prompted a further comparison of the rate at Ram equal to 104 with the total length of the heaters kept constant in all the cases. With respect to uniform heating of one entire wall, the study reveals a significant advantage of 246% rate enhancement from two equal heater segments placed centrally on opposite walls. This rate has emerged higher by 82% and 249%, respectively, with both the segments placed at the top and one at the bottom and one at the top. An increase in the number of centrally arranged heaters on each wall from one to five has yielded 286% rate enhancement. Changes in the ratio of the cavity height-to-length from 1.0 to 0.2 and 2 cause the rate to decrease by 50% and increase by 21%, respectively.
Research limitations/implications
Further research with additional parameters, geometries and configurations will consolidate the understanding. Experimental validation can complement the numerical simulations presented in this study.
Originality/value
This research contributes to the field by integrating segmented heating, magnetic fields and hybrid nanofluid in a porous flow domain, addressing existing research gaps. The findings provide valuable insights for enhancing thermal performance, and controlling heat transfer locally, and have implications for medical treatments, thermal management systems and related fields. The research opens up new possibilities for precise thermal management and offers directions for future investigations.
Details
Keywords
Nirmal K. Manna, Abhinav Saha, Nirmalendu Biswas and Koushik Ghosh
This paper aims to investigate the thermal performance of equivalent square and circular thermal systems and compare the heat transport and irreversibility of magnetohydrodynamic…
Abstract
Purpose
This paper aims to investigate the thermal performance of equivalent square and circular thermal systems and compare the heat transport and irreversibility of magnetohydrodynamic (MHD) nanofluid flow within these systems.
Design/methodology/approach
The research uses a constraint-based approach to analyze the impact of geometric shapes on heat transfer and irreversibility. Two equivalent systems, a square cavity and a circular cavity, are examined, considering identical heating/cooling lengths and fluid flow volume. The analysis includes parameters such as magnetic field strength, nanoparticle concentration and accompanying irreversibility.
Findings
This study reveals that circular geometry outperforms square geometry in terms of heat flow, fluid flow and heat transfer. The equivalent circular thermal system is more efficient, with heat transfer enhancements of approximately 17.7%. The corresponding irreversibility production rate is also higher, which is up to 17.6%. The total irreversibility production increases with Ra and decreases with a rise in Ha. However, the effect of magnetic field orientation (γ) on total EG is minor.
Research limitations/implications
Further research can explore additional geometric shapes, orientations and boundary conditions to expand the understanding of thermal performance in different configurations. Experimental validation can also complement the numerical analysis presented in this study.
Originality/value
This research introduces a constraint-based approach for evaluating heat transport and irreversibility in MHD nanofluid flow within square and circular thermal systems. The comparison of equivalent geometries and the consideration of constraint-based analysis contribute to the originality and value of this work. The findings provide insights for designing optimal thermal systems and advancing MHD nanofluid flow control mechanisms, offering potential for improved efficiency in various applications.
Graphical Abstract
Details
Keywords
Swetha Andra, Murugesan Muthalagu, Jaison Jeevanandam, Durga Devi Sekar and Rajalakshmi Ramamoorthy
A widespread focus on the plant-based antimicrobial cotton fabric finishes has been accomplished with notable importance in recent times. The antimicrobials prevent microbial…
Abstract
Purpose
A widespread focus on the plant-based antimicrobial cotton fabric finishes has been accomplished with notable importance in recent times. The antimicrobials prevent microbial dwelling in fabrics, which causes severe infections to the fabric users. Chemical disinfectants were conventionally used in fabrics to address this challenge; however, they were found to be toxic to humans. Thus, the present study aims to deal with the utilization of phytochemical extracts from different parts of Pongamia pinnata as antimicrobial coatings in cotton fabrics.
Design/methodology/approach
The root, bark and stem were collected and washed several times using tap water. Then, the leaves were dried at room temperature and the root and bark were dried using an oven at 40ºC. After drying, they were ground into fine powder and extracted with ethanol using the Soxhlet apparatus. After that the extract was coated on the fabric tested for antimicrobial studies.
Findings
The results reported that the leaf extract of P. pinnata-coated fabric exhibited enhanced antibacterial property towards gram-negative Escherichia coli bacteria, followed by root, bark and stem. The wash durability test in the extract-coated fabric samples revealed that dip-coating retained antibacterial activity until five washes. Thus, the current study clearly suggests that the leaf extract from P. pinnata is highly useful to develop antibacterial cotton fabrics as health-care textiles.
Originality/value
The novelty of the present work is to obtain the crude extract from the leaves, bark, root and stem of P. pinnata and evaluate their antibacterial activity against E. coli, upon being coated on cotton fibres. In addition, the extracts were subjected to wash durability analysis to study the coating efficiency of the phytochemicals in cotton fabrics and a probable mechanism for the antibacterial activity of P. pinnata extracts was also presented.
Details
Keywords
Liming Zhang, Yuxin Yi and Guichuan Zhou
This paper presents a meta-analysis of the electronic banking (e-banking) customer loyalty literature in the last 10 years. The study investigated the moderating role of national…
Abstract
Purpose
This paper presents a meta-analysis of the electronic banking (e-banking) customer loyalty literature in the last 10 years. The study investigated the moderating role of national culture in the relationship between e-banking customer loyalty and its antecedents.
Design/methodology/approach
Using a meta-analysis of customer loyalty in 19 countries, the authors incorporated national culture scores based on Hofstede's cultural dimensions to explore how the relative importance of e-banking customer loyalty antecedents varies across cultures.
Findings
The study revealed that national culture moderates the relationship between e-banking customer loyalty and its seven antecedents for four cultural dimensions, yet there was no significant moderation for satisfaction.
Research limitations/implications
This study reviewed the relationships in the literature on customer loyalty in e-banking contexts, extending and enriching the current knowledge. However, some specific limitations, such as the non-use of qualitative studies and the clipping of adverse concepts, exist in the secondary data and should be considered.
Practical implications
The results show that the seven antecedents affect e-banking customer loyalty to different degrees. Managers should incorporate cultural factors in e-banking customer management.
Originality/value
Only a few studies have assessed cultural differences in relation to e-banking customer loyalty. The authors address this need by offering deeper insights into how cultural dimensions moderate the relationships between e-banking customer loyalty and its antecedents through a meta-analytical review. The study findings offer managers a new perspective of leveraging the benefits of cultural differences, enhancing their decision-making in international business.