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Article
Publication date: 17 August 2018

Shipra Aggarwal and R.K. Pandey

The purpose of this paper is to conceive a new surface texture incorporating a tiny shape among the micro-pockets (with circular, rectangular, trapezoidal and triangular…

327

Abstract

Purpose

The purpose of this paper is to conceive a new surface texture incorporating a tiny shape among the micro-pockets (with circular, rectangular, trapezoidal and triangular cross-sections) and dimples (cylindrical, hemispherical and ellipsoidal) for exploring to enhance the maximum possible performance behaviors of sector shape pad thrust bearing.

Design/methodology/approach

Numerical simulation of hydrodynamically lubricated sector shape textured pad thrust bearing has been presented incorporating thermal and cavitation effects. The coupled solution of governing equations (Reynolds equation, film thickness expression, viscosity–temperature relation, energy equation and Laplace equation) has been achieved using finite difference method and Gauss–Seidel iterative scheme.

Findings

With new textured pads, higher load-carrying capacity and lower coefficient of friction are obtained in comparison to plain sector shape pad. Texture pattern comprising square cross-sectional pockets yields higher load-carrying capacity and lower coefficient of friction in comparison to other cross-sectional shapes (circular, trapezoidal and triangular) of pockets considered herein.

Originality/value

This study reports a new texture, which involves micro-pockets of square cross-sectional shapes to improve the performance behavior of sector shape pad thrust bearing. About 75 per cent increase in load carrying capacity and 42 per cent reduction in coefficient of friction have been achieved with pad having new texture in comparison to conventional pad.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

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Case study
Publication date: 30 July 2018

Goutam Dutta

S. R. Pandey, Superintending Engineer (SE), Rural Roads Department, Bihar wanted to have a meeting of all the agencies involved, including his other engineers, the contractors to…

Abstract

S. R. Pandey, Superintending Engineer (SE), Rural Roads Department, Bihar wanted to have a meeting of all the agencies involved, including his other engineers, the contractors to discuss his village road-making project in Pradhan Mantri Gram Sadak Yojona (PMGSY). This case discusses how the concept of work breakdown is used to subdivide all the activities of road-making into different sub activities (earthwork, bridgework, roadwork and other miscellaneous activities) in different levels.

Details

Indian Institute of Management Ahmedabad, vol. no.
Type: Case Study
ISSN: 2633-3260
Published by: Indian Institute of Management Ahmedabad

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Article
Publication date: 14 October 2024

Jyoti and Mandeep Singh

The aim of this work is to establish a computationally efficient iterative technique for solving the highly nonlinear derivative-dependent boundary value problem (DDBVP). The…

25

Abstract

Purpose

The aim of this work is to establish a computationally efficient iterative technique for solving the highly nonlinear derivative-dependent boundary value problem (DDBVP). The proposed iterative technique is tested on a one-dimensional mathematical model of the shape of the human cornea, which leads to the highly nonlinear DDBVP.

Design/methodology/approach

The approach is a combined venture of quasilinearization along with Picard’s iterative technique. The nonlinear DDBVP is simplified to a sequence of linear problems through a quasilinearization technique. Making use of Picard’s iteration approach, an analogous integral form for the quasilinearized DDBVPs is developed in terms of Green’s function and the convergence controller parameter. The study also covered the convergence analysis of the iterative technique.

Findings

Numerical illustrations are presented to evaluate the applicability, efficiency and accuracy of the technique. The proposed technique provides approximate numerical solutions to the corneal shape model with a variety of constant parameters that can arise in different physical situations. In comparison with existing works, the proposed coupled iterative approach has been found to be more accurate and less computationally complex.

Originality/value

This study introduces an efficient coupled iterative technique based on quasilinearization and Picard’s iterative technique to solve a one-dimensional model of a human cornea. The proposed approach is tested on various physical situations that affect the human cornea. Numerical findings are compared with other published results to demonstrate the method’s efficiency and ease of usage.

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Article
Publication date: 19 July 2019

Swati Yadav, Rajesh K. Pandey, Anil K. Shukla and Kamlesh Kumar

This paper aims to present a high-order scheme to approximate generalized derivative of Caputo type for μ ∈ (0,1). The scheme is used to find the numerical solution of generalized…

332

Abstract

Purpose

This paper aims to present a high-order scheme to approximate generalized derivative of Caputo type for μ ∈ (0,1). The scheme is used to find the numerical solution of generalized fractional advection-diffusion equation define in terms of the generalized derivative.

Design/methodology/approach

The Taylor expansion and the finite difference method are used for achieving the high order of convergence which is numerically demonstrated. The stability of the scheme is proved with the help of Von Neumann analysis.

Findings

Generalization of fractional derivatives using scale function and weight function is useful in modeling of many complex phenomena occurring in particle transportation. The numerical scheme provided in this paper enlarges the possibility of solving such problems.

Originality/value

The Taylor expansion has not been used before for the approximation of generalized derivative. The order of convergence obtained in solving generalized fractional advection-diffusion equation using the proposed scheme is higher than that of the schemes introduced earlier.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 9
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 2 July 2024

Deepak Byotra and Sanjay Sharma

This study aims to find the dynamic performance parameters of the journal bearing with micro geometries patterning the arc (crescent) shape textures provided in three specific…

164

Abstract

Purpose

This study aims to find the dynamic performance parameters of the journal bearing with micro geometries patterning the arc (crescent) shape textures provided in three specific regions of the journal bearing: the full, the second half and the increasing pressure region. The dynamic behavior of textured journal bearings has been analyzed by computing dynamic parameters and linear and non-linear trajectories.

Design/methodology/approach

The lubricant flows between the bearing and journal surface are governed by Reynold’s equation, which has been solved by finite the element method. The dynamic performance parameters such as stiffness, damping, threshold speed, critical mass and whirl frequency ratio are examined under various operating conditions by considering various ranges of eccentricity ratios and texture depths. Linear and non-linear equations of motion have been solved with Ranga–Kutta method to get journal motion trajectories. Also, the impact of adding aluminum oxide and copper oxide nanoparticles to the base lubricant in combination with arc-shaped textures is analyzed to further see any enhancement in the performance parameters.

Findings

The findings demonstrated that direct stiffness and damping parameters increased to their maximum level with six textures in the pressure-increasing region when compared with the untextured surface. Also, nanoparticle additives showed improvements above the highest value attained with no inclusion of additives in the same region or quantity of textures.

Originality/value

Engineers may design bearings with improved stability and overall performance if they understand how texture form impacts dynamic properties.

Details

Industrial Lubrication and Tribology, vol. 76 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 February 2023

Sumit Kumar Mehta and Sukumar Pati

The purpose of this paper is to investigate computationally the hydrothermal characteristics for forced convective laminar flow of water through a channel with a top wavy wall and…

237

Abstract

Purpose

The purpose of this paper is to investigate computationally the hydrothermal characteristics for forced convective laminar flow of water through a channel with a top wavy wall and a flat bottom wall having metallic porous blocks.

Design/methodology/approach

The governing equations are solved computationally using a finite element method–based numerical solver COMSOL Multiphysics® for the following range of parameters: 10 ≤ Reynolds number (Re) ≤ 500 and 10–4 ≤ Darcy number (Da) ≤ 10–1.

Findings

The presence of porous blocks significantly influences the heat transfer rate, and the value of local Nusselt number increases with the increase in Da. The value of the average Nusselt number decreases with Da for the top wall and the same is enhanced for the bottom wall of the wavy channel with porous blocks (WCPB). The value of the average Nusselt number for WCPB is significantly higher than that of the wavy channel without porous block (WCWPB), plane channel without porous block (PCWPB) and plane channel with the porous block (PCPB) at higher Re. For PCPB, the performance factor (PF) is always higher than that of WCWPB and WCPB for Da = 10–4 and Da = 10–3. Also, PF for WCPB is higher than that of WCWPB for higher Re except for Da = 10–4. Further, the value of for WCPB is higher than that of PCPB at Da = 10–2 and 10–1 at Re = 500.

Practical implications

The current study is useful in designing efficient heat exchangers for process plants, solar collectors and aerospace applications.

Originality/value

The analysis of thermo-hydraulic characteristics for laminar flow through a channel with a top wavy wall and a flat bottom wall having metallic porous blocks have been analyzed for the first time. Further, a comparative assessment of the performance has been performed with a wavy channel without a porous block, a plane channel without a porous block and a plane channel with porous blocks.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 6
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 29 September 2022

Shafaq Idrees and Umer Saeed

In this article, the authors aims to introduce a novel Vieta–Lucas wavelets method by generalizing the Vieta–Lucas polynomials for the numerical solutions of fractional linear and…

141

Abstract

Purpose

In this article, the authors aims to introduce a novel Vieta–Lucas wavelets method by generalizing the Vieta–Lucas polynomials for the numerical solutions of fractional linear and non-linear delay differential equations on semi-infinite interval.

Design/methodology/approach

The authors have worked on the development of the operational matrices for the Vieta–Lucas wavelets and their Riemann–Liouville fractional integral, and these matrices are successfully utilized for the solution of fractional linear and non-linear delay differential equations on semi-infinite interval. The method which authors have introduced in the current paper utilizes the operational matrices of Vieta–Lucas wavelets to converts the fractional delay differential equations (FDDEs) into a system of algebraic equations. For non-linear FDDE, the authors utilize the quasilinearization technique in conjunction with the Vieta–Lucas wavelets method.

Findings

The purpose of utilizing the new operational matrices is to make the method more efficient, because the operational matrices contains many zero entries. Authors have worked out on both error and convergence analysis of the present method. Procedure of implementation for FDDE is also provided. Furthermore, numerical simulations are provided to illustrate the reliability and accuracy of the method.

Originality/value

Many engineers or scientist can utilize the present method for solving their ordinary or Caputo–fractional differential models. To the best of authors’ knowledge, the present work has not been used or introduced for the considered type of differential equations.

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Article
Publication date: 26 August 2024

Dharen Kumar Pandey, Waleed M. Al-ahdal, Faten Moussa and Hafiza Aishah Hashim

This study aims to comprehensively understand market reactions to Bursa Malaysia's announcement on mandatory climate-change-related disclosures, exploring sector-specific dynamics…

240

Abstract

Purpose

This study aims to comprehensively understand market reactions to Bursa Malaysia's announcement on mandatory climate-change-related disclosures, exploring sector-specific dynamics and cross-sectional influences.

Design/methodology/approach

The study uses event study methodology on 412 listed firms to analyze market reactions around the announcement date. The sector-wise analysis further delves into variations across industries. Cross-sectional analysis explores the significance of environmental, social and governance (ESG) scores and firm controls in explaining the differences across sample firms.

Findings

The event study reveals initial negative market reactions on the event day, with a subsequent shift from positive to negative cumulative impact, indicating the evolving nature of investor sentiment. The sector-wise analysis highlights heterogeneous effects, emphasizing the need for tailored strategies based on industry-specific characteristics. The cross-sectional findings underscore the growing importance of ESG factors, with firm size and performance influencing market reactions. Financial leverage and liquidity prove insufficient to explain cumulative abnormal return (CAR) differences, while past returns and volatility are influential technical factors.

Practical implications

The economic significance of the results indicates a growing trend where investors prioritize companies with more substantial ESG scores, potentially driving shifts in corporate strategies toward sustainability. Better ESG performance signifies improved risk management and long-term resilience in the face of market dynamics. Regulatory bodies may respond by enhancing ESG reporting requirements, while financial institutions integrate ESG factors into their models, emphasizing the benefits of sustainability and financial performance.

Originality/value

This research contributes to the existing literature by providing a nuanced analysis of market responses to climate-related disclosures, incorporating sector-specific dynamics and cross-sectional influences. The findings offer valuable insights for businesses and policymakers, emphasizing the need for tailored approaches to climate-related disclosure management.

Details

Review of Accounting and Finance, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1475-7702

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Article
Publication date: 20 March 2024

Priyanka Goyal and Pooja Soni

The present research study aims to explore the impact of the most recent Israeli–Palestinian conflict, which unfolded in October 2023, on global equity markets, including a wide…

678

Abstract

Purpose

The present research study aims to explore the impact of the most recent Israeli–Palestinian conflict, which unfolded in October 2023, on global equity markets, including a wide range of both emerging and developed markets (as per the Morgan Stanley Capital Investment country classification).

Design/methodology/approach

The market model of event study methodology, with an estimation window of 200 days and 28-day event window (including event day, i.e. October 7, 2023), has been employed to investigate the event’s impact on the stock markets of different countries, with 24 emerging countries and 23 developed countries. The daily closing prices of the prominent indices of all 47 countries have been analyzed to examine the impact of the conflict on emerging markets, developed markets and overall global equity markets. Additionally, cross-sectional regression analysis has been performed to investigate the possible explanations for abnormal returns.

Findings

The findings of the study suggest the heterogeneous impact of the selected event on different markets. Notably, emerging markets and the overall global equity landscape exhibited substantial negative responses on the event day, as reflected in average abnormal returns of −0.47% and −0.397%, respectively. In contrast, developed markets displayed resilience, with no significant negative impact observed on the day of the event. A closer examination of individual countries revealed diverse reactions, with Poland, Egypt, Greece, Denmark and Portugal standing out for their positive or resilient market responses. Poland, in particular, demonstrated significantly positive cumulative abnormal returns (CARs) of 7.16% in the short-term and 8.59% in the long-term event windows (−7, +7 and −7, +20, respectively), emphasizing its robust performance amid the geopolitical turmoil. The study also found that, during various event windows, specific variables had a significant impact on the CARs.

Practical implications

The study suggests diversification and monitoring of geopolitical risks are key strategies for investors to enhance portfolio resilience during the Israeli–Palestinian conflict. This study identifies countries such as Poland, Egypt, Greece, Denmark and Portugal with positive or resilient market reactions, providing practical insights for strategic investment decisions. Key takeaways include identifying resilient markets, leveraging opportunistic strategies and navigating market dynamics during geopolitical uncertainties.

Originality/value

As per the authors’ thorough investigation and review of the literature, the present study is the earliest attempt to explore the short-term and long-term impact of the 2023 Israeli–Palestinian conflict on equity markets worldwide using the event study approach and cross-sectional regression analysis.

Details

Journal of Economic Studies, vol. 51 no. 8
Type: Research Article
ISSN: 0144-3585

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Article
Publication date: 8 August 2020

Amit K. Verma, Narendra Kumar and Diksha Tiwari

The purpose of this paper is to propose an efficient computational technique, which uses Haar wavelets collocation approach coupled with the Newton-Raphson method and solves the…

469

Abstract

Purpose

The purpose of this paper is to propose an efficient computational technique, which uses Haar wavelets collocation approach coupled with the Newton-Raphson method and solves the following class of system of Lane–Emden equations:

(tk1y(t))=tω1f1(t,y(t),z(t)),
(tk2z(t))=tω2f2(t,y(t),z(t)),
where t > 0, subject to the following initial values, boundary values and four-point boundary values:
y(0)=γ1, y(0)=0, z(0)=γ2, z(0)=0,
y(0)=0, y(1)=δ1, z(0)=0, z(1)=δ2,
y(0)=0, y(1)=n1z(v1), z(0)=0, z(1)=n2y(v2),
where n1,n2,v1,v2(0,1) and k10,k20,ω1<1,ω2<1, γ1, γ2, δ1, δ2 are real constants.

Design/methodology/approach

To deal with singularity, Haar wavelets are used, and to deal with the nonlinear system of equations that arise during computation, the Newton-Raphson method is used. The convergence of these methods is also established and the results are compared with existing techniques.

Findings

The authors propose three methods based on uniform Haar wavelets approximation coupled with the Newton-Raphson method. The authors obtain quadratic convergence for the Haar wavelets collocation method. Test problems are solved to validate various computational aspects of the Haar wavelets approach. The authors observe that with only a few spatial divisions the authors can obtain highly accurate solutions for both initial value problems and boundary value problems.

Originality/value

The results presented in this paper do not exist in the literature. The system of nonlinear singular differential equations is not easy to handle as they are singular, as well as nonlinear. To the best of the knowledge, these are the first results for a system of nonlinear singular differential equations, by using the Haar wavelets collocation approach coupled with the Newton-Raphson method. The results developed in this paper can be used to solve problems arising in different branches of science and engineering.

Details

Engineering Computations, vol. 38 no. 2
Type: Research Article
ISSN: 0264-4401

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