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1 – 10 of 17V.T.S. Dao, T.G. Etoh, M. Tanaka and T. Akino
The purpose of this paper is to minimize on‐chip inductance effect for modern very large‐scale integration (VLSI), ultra large‐scale integration (ULSI) systems.
Abstract
Purpose
The purpose of this paper is to minimize on‐chip inductance effect for modern very large‐scale integration (VLSI), ultra large‐scale integration (ULSI) systems.
Design/methodology/approach
As operating frequency increases, parasitic inductance has become a major concern for electronic design on both delay and coupling noises. The impacts of on‐chip inductance are strongly associated with higher frequency operation, denser interconnect geometry, reductions of resistance, and capacitance of interconnects. The paper presents a novel layout technique – opposing inter‐digitating routing, to generate magnetic fields in opposing directions; consequently, effective magnetic field is minimized, or inductance effect is reduced. To prove the effectiveness of these approaches, 3D field solver FastHenry is used to extract inductance data and verify the results.
Findings
Verification shows that this proposed method gives more than ten times reduction in self‐inductance while mutual inductance reduces even faster, without incurring any area and resource penalty.
Originality/value
The proposed technique can be used effectively to minimize inductance effects in the design of modern interconnect structures. This technique is shown to be highly effective for inductance reduction in wide signal buses which are used frequently in global buses, critical data path or clock distribution networks of VLSI and ULSI systems.
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Shuichi Torii and Wen‐Jei Yang
A theoretical study is performed to investigate transport phenomena in channel flows under uniform heating from either both side walls or a single side. The anisotropic t…
Abstract
A theoretical study is performed to investigate transport phenomena in channel flows under uniform heating from either both side walls or a single side. The anisotropic t2¯− εt heat‐transfer model is employed to determine thermal eddy diffusivity. The governing boundary‐layer equations are discretized by means of a control volume finite‐difference technique and numerically solved using a marching procedure. It is found that under strong heating from both walls, laminarization occurs as in the circular tube flow case; during the laminarization process, both the velocity and temperature gradients in the vicinity of the heated walls decrease along the flow, resulting in a substantial attenuation in both the turbulent kinetic energy and the temperature variance over the entire channel cross section; both decrease causes a deterioration in heat transfer performance; and in contrast, laminarization is suppressed in the presence of one‐side‐heating, because turbulent kinetic energy is produced in the vicinity of the other insulated wall.
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Nusselt-Rayleigh-Fourier type correlations are proposed to quantify the temporal evolution of convective heat transfer occurring within air-filled hemispherical enclosures…
Abstract
Purpose
Nusselt-Rayleigh-Fourier type correlations are proposed to quantify the temporal evolution of convective heat transfer occurring within air-filled hemispherical enclosures whose disk, initially at ambient temperature, is suddenly maintained at a higher temperature. The temperature difference imposed between this hot wall and the isothermal cold dome involves Rayleigh number varying between 104 and 2.55×1012. Depending on the application, the disk can be inclined with respect to the horizontal plane by an angle varying between 0° (horizontal disk) and 90° (vertical disk) in steps of 15°. The paper aims to discuss these issues.
Design/methodology/approach
The results are obtained by means of a numerical approach based on the finite volume method. The proposed correlations linked to the steady state Nusselt-Rayleigh internships recently published, concerning the same inclination angle and Rayleigh ranges.
Findings
The statistical analysis of a large number of calculations leads to reliable results covering laminar, transitional and turbulent natural convection heat transfer zones.
Practical implications
The proposed relationships can be applied in several engineering fields such as nuclear technology, solar energy, security and safety electronics, building, domotics or aeronautics.
Originality/value
The new relationships proposed in this paper provide important information on the evolution of convective heat transfer during the transient regime.
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Shantanu Dutta, Arup Kumar Biswas and Sukumar Pati
The purpose of this paper is to analyze the natural convection heat transfer and irreversibility characteristics in a quadrantal porous cavity subjected to uniform…
Abstract
Purpose
The purpose of this paper is to analyze the natural convection heat transfer and irreversibility characteristics in a quadrantal porous cavity subjected to uniform temperature heating from the bottom wall.
Design/methodology/approach
Brinkmann-extended Darcy model is used to simulate the momentum transfer in the porous medium. The Boussinesq approximation is invoked to account for the variation in density arising out of the temperature differential for the porous quadrantal enclosure subjected to uniform heating on the bottom wall. The governing transport equations are solved using the finite element method. A parametric study is carried out for the Rayleigh number (Ra) in the range of 103 to 106 and Darcy number (Da) in the range of 10−5-10−2.
Findings
A complex interaction between the buoyant and viscous forces that govern the transport of heat and entropy generation and the permeability of the porous medium plays a significant role on the same. The effect of Da is almost insignificant in dictating the heat transfer for low values of Ra (103, 104), while there is a significant alteration in Nusselt number for Ra ≥105 and moreover, the change is more intense for larger values of Da. For lower values of Ra (≤104), the main contributor of irreversibility is the thermal irreversibility irrespective of all values of Da. However, the fluid friction irreversibility is the dominant player at higher values of Ra (=106) and Da (=10−2).
Practical implications
From an industrial point of view, the present study will have applications in micro-electronic devices, building systems with complex geometries, solar collectors, electric machinery and lubrication systems.
Originality/value
This research examines numerically the buoyancy driven heat transfer irreversibility in a quadrantal porous enclosure that is subjected to uniform temperature heating from the bottom wall, that was not investigated in the literature before.
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Abderrahmane Baïri, Jean-Gabriel Bauzin, Alexander Martín-Garín, Nacim Alilat and José Antonio Millán-García
The purpose of this study is to determine the thermal behavior of a hemispherical electronic device contained in a concentric hemispherical enclosure, cooled by means of…
Abstract
Purpose
The purpose of this study is to determine the thermal behavior of a hemispherical electronic device contained in a concentric hemispherical enclosure, cooled by means of free convection through a porous medium saturated with a water–copper nanofluid. Influence of various parameters on the thermal state of this device is processed in this work. The high power generated by the dome leads to a Rayleigh number varying in the 5.2 × 107-7.29 × 1010 range. The volume fraction of the monophasic nanofluid varies between 0 (pure water) and 10 per cent while the base of the hemispherical cavity (disc) is inclined between 0° (horizontal disc with dome facing upward) and 180° (horizontal disc with dome facing downward).
Design/methodology/approach
The three-dimensional numerical approach is carried out by means of the volume control method associated to the SIMPLE algorithm.
Findings
The work shows that the average temperature of the active component increases with the Rayleigh number according to a conventional law of the power type. The increase in the angle of inclination also goes with a systematic rise in the average temperature. However, increasing the ratio of the solid–fluid thermal conductivities decreases the average temperature of the component, given the respective contributions of the conductive and natural convective phenomena occurring through the nanofluid saturated porous media. The values of this ratio vary in this work between 0 (interstice between the two hemispheres without porous medium) and 70.
Originality/value
The correlation proposed in this work allows to calculate the temperature of the active electronic component for all the combinations of the four influence parameters which vary in wide ranges.
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Abderrahmane Baïri, Juan Mario García de María, Nacim Alilat, Najib Laraqi and Jean-Gabriel Bauzin
The purpose of this paper is to propose correlations between Nusselt and Rayleigh numbers for the case of inclined and closed air-filled hemispherical cavities. The disk…
Abstract
Purpose
The purpose of this paper is to propose correlations between Nusselt and Rayleigh numbers for the case of inclined and closed air-filled hemispherical cavities. The disk of such cavities is subjected to a constant heat flux. The study covers a wide range of Rayleigh numbers from 5×107 to 2.55×1012.
Design/methodology/approach
Correlations are obtained from numerical approach validated by experimental measurements on some configurations, valid for several angles of inclination of the cavity between 0° (horizontal disk) and 90° (vertical disk) in steps of 15°.
Findings
The statistical analysis of a large number of calculations leads to reliable results covering laminar, transitional and turbulent natural convection heat transfer zones.
Practical implications
The proposed correlations provide solutions for applications in several fields of engineering such as solar energy, aerospace, building, safety and security.
Originality/value
The new relations proposed are the first published for high Rayleigh numbers for this type of geometry. They supplement the knowledge of natural convection in hemispherical inclined cavities and constitute a useful tool for application in various engineering areas as solar energy (thermal collector, still, pyranometer, albedometer, pyrgeometer), aerospace (embarked electronics), building, safety and security (controlling and recording sensors).
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Abderrahmane Baïri, Nagaraj Suresh, Palanisamy Gayathri, Nagarajan Nithyadevi and Purusothaman Abimanyu
A porous medium saturated with a nanofluid based on pure water and copper nanoparticles is used for cooling a hemispherical electronic device contained in an annulus…
Abstract
Purpose
A porous medium saturated with a nanofluid based on pure water and copper nanoparticles is used for cooling a hemispherical electronic device contained in an annulus space. The disc of the cavity could be inclined at an angle ranging from 0 ° (horizontal disc with dome facing upwards) to 180° (horizontal disc with dome facing downwards). The important surface heat flux generated by the dome leads to high Rayleigh number values reaching 7.29 × 10^10. The purpose of this work is to examine the influence of the nanofluid saturated porous medium on the free convective heat transfer.
Design/methodology/approach
Heat transfer occurring between this active component and the isothermal passive cupola is quantified by means of a three-dimensional numerical study using the control volume method associated to the SIMPLE algorithm.
Findings
The work shows that heat transfer in the annulus space is improved by interposing a porous medium saturated with the water-copper nanofluid.
Originality/value
New correlation is proposed to calculate the Nusselt number for any combination of the inclination angle, the fraction volume, the Rayleigh number and the ratio between the thermal conductivities of the porous medium and the fluid. The wide ranges corresponding to these parameters allow the thermal design of this electronic equipment for various configurations.
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Chamila R. Perera and Chandana R. Hewege
Applying mainstream, Western-centric corporate social responsibility (CSR) theory to make sense of CSR practices of multinational firms of non-Western origin seems to be…
Abstract
Purpose
Applying mainstream, Western-centric corporate social responsibility (CSR) theory to make sense of CSR practices of multinational firms of non-Western origin seems to be problematic for CSR theory and practice. The purpose of this study is to critically analyse the CSR integration journey of a Japanese multinational firm with a view to understanding CSR integration in a global business context.
Design/methodology/approach
This study used a qualitative research method using a single case study approach to investigate a contemporary phenomenon within its real-life context. A theoretical lens of seven patterns of CSR integration interwoven with Japanese and mainstream CSR discourses is used to make sense of internalisation and internationalisation process.
Findings
Main findings are presented under four themes: product harm crisis as a call for CSR, CSR governance and bottom up initiatives, recycling oriented CSR and product designing, co-existing Japanese CSR in the global marketplace. An external misfit of a firm’s practice in the domestic market can lead to internalising country-specific CSR through CSR integration resulting in successful internationalisation of country-specific CSR practices.
Research limitations/implications
Country-specific CSR integration follows context-specific routines and practices; this process can be shaped and reshaped by the prevailing international CSR discourse due to internationalisation of a firm’s operation.
Originality/value
Although CSR is viewed as a fundamental strategic priority driving firms to focus on shared value-creating products and services, how best a firm can integrate CSR into an existing business model is unclear. This gap is addressed in this current study.
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Meghna Chhabra, Lata Bajpai Singh and Syed Asif Mehdi
Women entrepreneurs contribute significantly to Asian economies. However, women in this region face an alarming array of barriers to entrepreneurship. This research study…
Abstract
Purpose
Women entrepreneurs contribute significantly to Asian economies. However, women in this region face an alarming array of barriers to entrepreneurship. This research study aims to examine the factors, i.e. government support, family social support, financial literacy and managerial skills, in building the entrepreneurial capacity of women entrepreneurs under the lens of the person–environment (P-E) fit theory. Furthermore, the study also examines the moderating effect of socio-cultural barriers in the said relationships.
Design/methodology/approach
For the study, the data was collected from the owners of 311 women-owned manufacturing and services sector enterprises from the northern Indian community.
Findings
Findings suggest that all the factors significantly affect the entrepreneurial capacity of women entrepreneurs, and the barriers work as a moderator between the relationships.
Originality/value
Based on P-E fit theory, this unique research study proposes a model to test the role of factors such as government support, family social support, financial literacy and managerial skills in developing women entrepreneurs’ entrepreneurial capacity along with examining the moderating role of socio-cultural factors contributing to the entrepreneurial capacity of women.
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Purnima Rao, Shubhangi Verma, Akshat Aditya Rao and Rajni Joshi
The purpose of the current paper is to identify the factors responsible for achieving business sustainability. This paper further attempts to develop a conceptual…
Abstract
Purpose
The purpose of the current paper is to identify the factors responsible for achieving business sustainability. This paper further attempts to develop a conceptual framework that can help SMEs to achieve viable business growth through improved sustainable performance.
Design/methodology/approach
The study follows a methodical examination of literature published on SMEs during COVID-19. Specifically, the combination of keywords has primarily centred on SMEs, Business Practices, COVID-19 and Pandemic. The 155 research papers identified for the analysis have been classified as per geographical spread, type of papers, central theme, and theoretical foundations, which finally is followed by rigourous thematic analysis.
Findings
This research contributes to the SME literature by providing methodological, conceptual and practical rigour. The framework proposed by the research covers all the relevant areas which can be useful in preparing sustainable business trajectory for SMEs. It outlines the required directives for designing sustainable business practices for SMEs and includes macro and micro determinants. It also opens up future research avenues in different areas identified in the research. Future research can be performed on comparing business practices of SMEs across the emerging and developed economies.
Practical implications
In this study, we propose a framework that enables the design of sustainable business practices and thereby supports SMEs to combat any uncertain events or shocks. SMEs that can work on adopting sustainable business practices may sculpt novel avenues for growth and competitive advantage for their business.
Originality/value
The study is distinctive in nature as it is based on the examination of literature published during a phenomenological event (COVID-19) which depicts the sudden and unaccounted disruptions faced by SMEs and thereby strategies formulated around the significant glitches.
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