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1 – 9 of 9Julius Wilker, Tim Göttlich, Thorsten Helmig, Rafael Solana Gómez, Hossein Askarizadeh and Reinhold Kneer
Particularly during machining, large heat sources and thus high temperature gradients and mechanical stress occur in the cutting zone. By using cutting fluids, part of the heat…
Abstract
Purpose
Particularly during machining, large heat sources and thus high temperature gradients and mechanical stress occur in the cutting zone. By using cutting fluids, part of the heat generated can be dissipated, thereby reducing local temperatures. To quantify the cooling efficiency of the cutting fluid, the flow behaviour of the cutting fluid in vicinity of the cutting zone must be determined to derive the resulting convective heat transfer coefficients at the tool. The purpose of this paper is to investigate the local distribution of the convective heat transfer coefficient as a function of the flow boundary conditions, specifically evaluating the effects of Reynolds number, injection angle and nozzle radius.
Design/methodology/approach
The geometries, temperature fields as well as the heat sources resulting during the machining process are extracted from a chip formation simulation using finite element method (FEM) and used to set up a three-dimensional computational fluid dynamics (CFD) flow simulation.
Findings
On the tool rake face, the local distribution of the convective heat transfer coefficient can be divided into three regions. Firstly, the region where the liquid impinging jet initially strikes, then a region near the chip where the flow is strongly deflected and then the remaining region in the boundary layer region. For each region, a function is derived that describes its position, subsequently the mean convective heat transfer coefficient is determined and summarised in a Nusselt correlation as a function of the flow parameters.
Research limitations/implications
Simulation results reveal that the distribution of the convective heat transfer coefficient on the tool rake face can be divided into three distinct regions: the impingement zone where the impinging jet first strikes, the deflection zone near the chip where the flow sharply redirects and the boundary layer zone covering the remaining surface. A geometric function is derived to describe the position and extent of each of these areas. In addition, the mean convective heat transfer coefficient can be determined for each of the regions using a Nusselt correlation based on the flow parameters.
Practical implications
These correlations allow for simplified determination of the local convective heat transfer coefficient on the tool.
Originality/value
This paper introduces an innovative approach for estimating the local distribution of the convective heat transfer coefficient at the tool rake face during orthogonal cutting under cutting fluid supply. The influence of the three-dimensional flow field of the cutting fluid jet of the convective heat transfer coefficient on the tool rake face is analysed in detail in the vicinity of the chip as a function of varying Reynolds numbers, nozzle radii and injection angles within a three-dimensional geometry.
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Muhammed Gur, Hakan Oztop, Nirmalendu Biswas and Fatih Selimefendigil
The purpose of this study is to investigate the impact of swirling jet flow on the cooling performance of a heated rectangular prism placed within a channel. The primary aim is to…
Abstract
Purpose
The purpose of this study is to investigate the impact of swirling jet flow on the cooling performance of a heated rectangular prism placed within a channel. The primary aim is to explore the influence of varying aspect ratios (AR) of the prism and different fluid Reynolds numbers (Re) on the cooling efficiency.
Design/methodology/approach
The numerical analysis is performed using a finite volume-based solver, which incorporates the large eddy simulations (LES) turbulence model. The setup consists of twin 45° swirling jets directed at isothermally heated bodies, with water used as the cooling medium. The rectangular prism is oriented perpendicularly to the channel flow direction, positioned one unit distance from the inlet. This study examines three distinct aspect ratios (AR = 0.5, 1 and 1.5) and a range of Reynolds numbers (6000 = Re = 20000).
Findings
The results indicate that cooling efficiency improves as the aspect ratio decreases and the Reynolds number increases. Higher Reynolds numbers enhance jet impingement and turbulent mixing, which are crucial for efficient heat transfer. Conversely, lower Reynolds numbers lead to diminished impingement and reduced cooling efficiency. Increasing the Reynolds number from 6000 to 20000 elevates the average Nusselt number by 35% (for AR = 0.5) and up to 45% (for AR = 1.5). It was observed that lower aspect ratios produce superior cooling effects due to intensified localized jet interactions.
Originality/value
This research significantly contributes to the fields of fluid dynamics and thermal engineering by elucidating the influence of swirling jet flows on the cooling of heated surfaces. The findings offer valuable insights for optimizing the design and performance of cooling systems across various industrial applications.
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Suhail Hyder Vattathurvalappil, Taha Najam, Mohammed Aves, Abrar H. Baluch, Usman Ali and Aamer Nazir
Continuous fiber thermoplastics are recyclable and have excellent specific strength and stiffness, making them desirable materials for use in structural components. Recent…
Abstract
Purpose
Continuous fiber thermoplastics are recyclable and have excellent specific strength and stiffness, making them desirable materials for use in structural components. Recent advancements in continuous fiber additive manufacturing processes allow designers to make notches or perforations during printing, eliminating the need for labor-intensive and long drilling processes, which cause delaminations and premature failure. The purpose of this study is to evaluate the potential of continuous fiber 3D printing in creating notches for structural composites.
Design/methodology/approach
This study evaluates the notching process in nylon-based continuous-glass fiber thermoplastic composites through mechanical drilling and three-dimensional (3D) printing. Three different sample configurations were tested for tensile and fracture characteristics: Un-notched; with notches drilled mechanically; and with notches printed using a 3D printer, with the fibers routed around the notch. Further, finite element models were used to understand the stress concentration around the notches.
Findings
The tensile strength of notched samples was lower than that of unnotched samples in both 3D-printed and mechanically drilled cases. The presence of substantial delamination in mechanically drilled samples led to a 15% decrease in strength compared to 3D-printed samples. The increase in notch size resulted in a decrease in strength, as anticipated.
Practical implications
The techniques developed in this study may be easily applied to comparable situations involving several types of continuous fiber thermoplastic composites.
Originality/value
Both experimental and computational modeling results indicate that delamination because of the drilling process is the prime factor responsible for the significant decrease in residual strength. Furthermore, it also showed that the steering of the fiber around the notch had a minimal impact, and augmenting the stiffness in proximity to the notch can alleviate stress concentration.
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Olanrewaju Kareem, Olayemi Abdullateef Aliyu and Maruf Gbadebo Salimon
The performance of business enterprises is an impetus to every nation’s growth and development, as they constitute a multitude of businesses in most countries in the world. While…
Abstract
Purpose
The performance of business enterprises is an impetus to every nation’s growth and development, as they constitute a multitude of businesses in most countries in the world. While ethical crises in the workplace are causing serious depletion in organizational performance and, in some cases, leading to total bankruptcy and the collapse of business in a developing country. This study aims to empirically examine the interaction effect of Islamic work ethics (IWEs) on the linkage between organization culture (OC) and enterprise performance (EP).
Design/methodology/approach
The survey method collected data from 531 managers of firms in the SME category of enterprises, using validated measurement instruments adapted from previous studies, and the data were quantitatively analyzed with Smart PLS SEM.
Findings
The results indicate that OC has a positive and significant effect on EP. The study also found that IWEs had a strong positive and significant impact on EP. The investigation revealed a significant effect of IWEs on the OC impact on EP. Therefore, we concluded that increased IWE practice will enhance the OC impact on EP.
Originality/value
This study contributes to the nexus of OC and EP as the first to investigate the interaction effect of IWE in an African context. Furthermore, the study suggests that if enterprise managers can exhibit Islamic work values, it will communicate and stimulate workers’ positive attitudes toward the organization. The creation of a harmonious and unethical behavior-free workplace environment would lead to improved enterprise performance. We presented theoretical and practical implications, along with recommendations for future research.
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Mohd Nazim Mat Nawi, Muhammad Ashraf Fauzi, Irene Wei Kiong Ting, Walton Wider and Gabari Barry Amaka
This study provide an in-depth review on the knowledge structure of green information technology (GIT) adoption and behavior. Environmental degradation has escalated even further…
Abstract
Purpose
This study provide an in-depth review on the knowledge structure of green information technology (GIT) adoption and behavior. Environmental degradation has escalated even further with information and digital technology development. Researchers have come up with a new concept of GIT to dampen the carbon emission due to the excessive use of IT in today’s everyday usage. A similar terminology, green information system (GIS), is a rather broad understanding of GIT, which relates to the environmental management system to improve operations in the organization and will be included in the scope of the study.
Design/methodology/approach
This study presents a science mapping analysis through a bibliometric review to explore emerging trends and predict future trends based on 293 publications in the Web of Science.
Findings
The bibliographic coupling analysis discovered five themes related to the theoretical foundation of GIT and the determinants of their adoption. The five themes are (1) theoretical foundation in GIT, (2) determinants of green IT and IS adoption, (3) fundamental of GIT and information science, (4) green technologies and green computing and (5) determinants of managers green IT adoption behavior. While co-word analysis presents the impact of GIT, driving performance and energy efficiency through the adoption of GIT producing four themes, (1) GIT acceptance through the theory of planned behavior, (2) impact of GIT’s: strategies for sustainable implementation, (3) driving sustainable performance through green innovation in information systems and technology and (4) energy efficiency and sustainability in green computing and cloud computing.
Research limitations/implications
The finding is relevant to managers, researchers and stakeholders bounded by environmental responsibilities to mitigate its impact on the socioeconomic and environment through GIT adoption.
Originality/value
The contribution of this study is presenting an in-depth analysis of the knowledge structure through bibliometric analysis by providing network visualization on one of the crucial pro-environmental behavior.
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Umaira Tabassum, Xing Qiang, Jaffar Abbas, Amjad Islam Amjad and Khalid Ibrahim Al-Sulaiti
Positive psychology helps us understand the knowledge required to contribute to adolescents' societal development and adjustability. Adolescence is the crucial stage to work on…
Abstract
Purpose
Positive psychology helps us understand the knowledge required to contribute to adolescents' societal development and adjustability. Adolescence is the crucial stage to work on for a balanced personality. The present study concerned adolescents' self-strength, happiness, and help-seeking behaviour. The authors aimed to explore the relationship between adolescents' self-strength and happiness and investigate the mediational effect of adolescents' help-seeking behaviour on their self-strength and happiness.
Design/methodology/approach
The research design of the current quantitative study was correlational, and 809 adolescents from China and Pakistan participated in the present study. Data were personally collected from participants through self-developed scales.
Findings
We deployed Pearson correlation and simple mediation using SPSS software and found a linear, positive, strong (r = 0.654, n = 809, p = 0.000 < 0.01) and statistically significant correlation between adolescents' self-strength and happiness. The authors also found a significant indirect effect of help-seeking on adolescents' self-strength and happiness at (β = 0.373, t(907) = 7.01).
Research limitations/implications
Using self-reported scales to gather information was one of the study's limitations. Adolescents may have misunderstood the notion or construct narrated in words or responded biasedly despite the bilingual scales.
Practical implications
This study offers social and practical implications for educators, parents, and school administrators to address the development of adolescents' personalities using a positive psychology lens.
Originality/value
The findings are of significant importance for teachers working in the elementary schools. They may work on adolescents' self-strength, happiness, and help-seeking to develop balanced personalities.
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Dg Nooremah Ag Said, Rose Irnawaty Ibrahim, Azman Ab Rahman and Hafidzi Hamdan
This paper aims to view the tradition of the Prophet in zakat payment, especially the attributed measurements, and adapt these measures to current zakat measurement practices.
Abstract
Purpose
This paper aims to view the tradition of the Prophet in zakat payment, especially the attributed measurements, and adapt these measures to current zakat measurement practices.
Design/methodology/approach
This study is designed with an exploratory sequential mixed method where qualitative data were collected from historical archives and also from the measurement of available ṣāʿ صاع and mud_ مد. These standard measures were collected from Malaysia and other Muslim countries and calibrated at the National Measurement Standards Laboratory (currently carried out by the National Metrology Institute of Malaysia). The volume of the ṣāʿ were tabulated, charted, analyzed and determined.
Findings
Prophet Muḥammad ordered for zakat al-fiṭr زكاة الفطر to measure the crops using ṣāʿ (gallon: volume measure), not raṭl رطل (pound: standard weight). This paper recommends a reference volume for the ṣāʿ, and from this value, the volume for the smaller measure mud and much larger measure wasq وسق were calculated. The agricultural niṣāb
(5 wasq) is one of the key parameters in ṣāʿ volume analysis.
Research limitations/implications
This study covers standard measures acquired from Malaysia, Saudi Arabia and the United Kingdom (traceable to India). Several empirical data are attained from previous studies from Saudi Arabia and North Africa. Also, some theoretical data are obtained from kitab tafsir, hadith and kitab turath (books and records written by early scholars). A concern in this study is the ratio of de-husked grains currently approximated at half of un-hulled grains. This might not necessarily be accurate and may differ by different types of grains.
Practical implications
After the introduction of the modern measurement system known as the International System of Units (SI) in 1971, ṣāʿ became obsolete, leaving each state in Malaysia to define and convert ṣāʿ to SI units variously. This paper contributes to standardizing the conversion to one value with an appropriate SI unit, that has traceability to the Prophet’s ṣāʿ. This national reference standard ṣāʿ is essential for zakat al-fiṭr measurement, important for zakat centers and impacting every Muslim in Malaysia. Often overlooked, ṣāʿ is more crucial as a basis in determining and standardizing the seasonal crops niṣāb, unfolding the reasons why the poor are paying the paddy zakat in Malaysia.
Social implications
The Prophet’s tradition for ablution is to use water not more than one mud, this is aligned with the 12th Sustainable Development Goals by the United Nations which promoted the responsible consumption of water. Considering half (adults) of the 1.9 billion Muslims in the world, multiplied by 5 times of prayer, the Muslims will at least use 4.75 billion muds of water for ablution alone in 1 day. This is approximately 3.5 billion liters of water daily, and if they limit their water usage to 1 mud for each ablution, they collectively will save at least four times more water (about 14 billion liters) daily than performing ablution from a running tap. Though for ablution, accuracy is not an issue, the mud impact on all Muslims is vital on a daily basis, literally by volume.
Originality/value
Ṣāʿ is essential in measuring food for the annually obligated zakat al-fiṭr and more crucial as a basis in determining the seasonal crops niṣāb. This paper contributes to the development of a national reference standard ṣāʿ for Malaysia that has traceability to the Prophet’s ṣāʿ.
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The primary purpose of this research is to conceptualise and validate the comprehensive framework for effectively measuring and managing employee-based brand equity (EBBE…
Abstract
Purpose
The primary purpose of this research is to conceptualise and validate the comprehensive framework for effectively measuring and managing employee-based brand equity (EBBE) benefits. The study endeavours to integrate professional and socio-emotional facets of employees' into the proposed model, lending it a more holistic approach.
Design/methodology/approach
The study focusses on the banking sector in Kosovo, employing structural equation modelling to analyse data from a sample of 325 employees.
Findings
Both professional and socio-emotional perspectives significantly influenced brand knowledge, positively impacting EBBE benefits such as employee satisfaction, retention and positive word of mouth (WOM). These findings provide empirical support for the theoretical assumptions concerning the role of professional and socio-emotional perspectives in building EBBE.
Research limitations/implications
Theoretically, this research could bridge marketing and organisational behaviour theories by highlighting employees' role in building brand equity. Moreover, it might expand the social identity theory within an organisational context, emphasising employees' identification with the brand as a crucial element.
Practical implications
The study offers practical implications for the banking industry and similar contexts, suggesting robust internal marketing strategies prioritising professional development and socio-emotional connectivity. Theoretically, this research could bridge marketing and organisational behaviour theories by highlighting employees' role in building brand equity. Moreover, it might expand the social identity theory within an organisational context, emphasising employees' identification with the brand as a crucial element.
Originality/value
The paper presents an original contribution to the field of brand equity research by proposing and validating a novel framework for EBBE that uniquely integrates both professional and socio-emotional dimensions of employees' experiences. This approach is particularly innovative within the context of the banking sector, offering new empirical insights.
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I Gede Mahatma Yuda Bakti, Sik Sumaedi, Medi Yarmen, Marlina Pandin, Aris Yaman, Rahmi Kartika Jati and Mauludin Hidayat
Recently, autonomous vehicles (AV) acceptance has been studied intensively. This paper aims to map and analyze the bibliometric characteristics of AV acceptance literature…
Abstract
Purpose
Recently, autonomous vehicles (AV) acceptance has been studied intensively. This paper aims to map and analyze the bibliometric characteristics of AV acceptance literature. Furthermore, this research aims to identify research gaps and propose future research opportunities.
Design/methodology/approach
The bibliometric analysis was performed. Scopus database was used as the source of the literature. This study selected and analyzed 297 AV acceptance papers. The performance and science mapping analysis were performed.
Findings
The developed countries tended to dominate the topic. The publication outlet tended to be in transportation or technology journals. There were four research themes in existing literature. Technology acceptance model (TAM) and UTAUT2 tended to be used for explaining AV acceptance. AV acceptance studies tended to use two types of psychological concepts for understanding AV acceptance, namely risk related concepts and functional utilitarian benefit related concepts. In the context of research design, quantitative approach tended to be used. Self-driving feature was the most exploited feature of AV in the existing literature. Three research gaps were mapped and future research opportunities were proposed.
Practical implications
This paper provided a comprehensive information that allowed scientists to develop future research on AV acceptance.
Originality/value
There is lack of paper that discussed the bibliometric characteristics of AV acceptance literature. This paper fulfilled the gap.
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