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Article
Publication date: 29 March 2013

Alper Korkmaz and İdris Dağ

The purpose of this paper is to simulate numerical solutions of nonlinear Burgers' equation with two well‐known problems in order to verify the accuracy of the cubic B‐spline…

617

Abstract

Purpose

The purpose of this paper is to simulate numerical solutions of nonlinear Burgers' equation with two well‐known problems in order to verify the accuracy of the cubic B‐spline differential quadrature methods.

Design/methodology/approach

Cubic B‐spline differential quadrature methods have been used to discretize the Burgers' equation in space and the resultant ordinary equation system is integrated via Runge‐Kutta method of order four in time. Numerical results are compared with each other and some former results by calculating discrete root mean square and maximum error norms in each case. A matrix stability analysis is also performed by determining eigenvalues of the coefficient matrices numerically.

Findings

Numerical results show that differential quadrature methods based on cubic B‐splines generate acceptable solutions of nonlinear Burgers' equation. Constructing hybrid algorithms containing various basis to determine the weighting coefficients for higher order derivative approximations is also possible.

Originality/value

Nonlinear Burgers' equation is solved by cubic B‐spline differential quadrature methods.

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Article
Publication date: 23 August 2011

Alper Korkmaz and İdris Dağ

This paper aims to present a numerical solution of non‐linear Burger's equation using differential quadrature method based on sinc functions.

704

Abstract

Purpose

This paper aims to present a numerical solution of non‐linear Burger's equation using differential quadrature method based on sinc functions.

Design/methodology/approach

Sinc Differential Quadrature Method is used for space discretization and four stage Runge‐Kutta algorithm is used for time discretization. A rate of convergency analysis is also performed for shock‐like solution. Numerical stability analysis is performed.

Findings

Sinc Differential Quadrature Method generates more accurate solutions of Burgers' equation when compared with the other methods.

Originality/value

This combination, Sinc Differential Quadrature and Runge‐Kutta of order four, has not been used to obtain numerical solutions of Burgers' equation.

Details

Engineering Computations, vol. 28 no. 6
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 26 October 2012

Alper Korkmaz and İdris Dağ

Cubic B‐spline differential quadrature methods have been introduced. As test problems, two different solutions of advection‐diffusion equation are chosen. The first test problem…

538

Abstract

Purpose

Cubic B‐spline differential quadrature methods have been introduced. As test problems, two different solutions of advection‐diffusion equation are chosen. The first test problem, the transportion of an initial concentration, and the second one, the distribution of an initial pulse, are simulated. The purpose of this paper is to simulate the test problems.

Design/methodology/approach

The cubic B‐spline functions are chosen as test functions in order to construct the differential quadrature method. The error between the numerical solutions and analytical solutions are measured using various error norms.

Findings

The cubic B‐spline differential quadrature methods have produced acceptable solution for advection‐diffusion equation.

Originality/value

The advection‐diffusion equation has never been solved by any differential quadrature method based on cubic B‐splines.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 22 no. 8
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 2 October 2024

Alper Uğur

As lubricating oils are used, their performance deteriorates and they become contaminated. The purpose of this paper is to investigate the lubrication performance of reclaimed…

58

Abstract

Purpose

As lubricating oils are used, their performance deteriorates and they become contaminated. The purpose of this paper is to investigate the lubrication performance of reclaimed 5 W-30 a fully synthetic used engine oil (UEO) with wear tests after refining it from a solvent-based extraction method using solvent (1-PrOH) and adsorbent materials such as cement, celite and deep eutectic solvent (DES).

Design/methodology/approach

The treated oil mixtures were prepared by blending engine oils with various adsorbent materials at 5% (w/w) in organic 1-PrOH solvent at a UEO: solvent ratio of 1:2 (w/w). The measurement of kinematic viscosity, density, the total acid number (TAN) and elemental analysis of oil samples was done by the ASTM standards D445/D446, D4052, D974 and D6595, respectively. Adsorbents and treated oil samples characterized by SEM-EDX, FTIR and UV analysis, respectively. Meanwhile, lubricating performance in tribological applications was evaluated through the wear test device using a rotating steel alloy 1.2379 cylinder and a stationary 1.2738 pin under 20, 40 and 80 kg load conditions. Worn surface analysis was done with SEM and 2.5D images.

Findings

It was found that when using the combination of cement and celite as an adsorbent in the reclamation of used engine oil demonstrated better lubricant properties. The properties of used engine oil were improved in the manner of kinematic viscosity of 32.55 from 68.49 mm2/s, VI (Viscosity index) value of 154 from 130, TAN of 3.18 from 4.35 (mgKOH/g) and Fe content of 11 from 32 mg/L. The anti-wear properties of used engine oil improved by at least 32% when 5% cement and 5% celite adsorbent materials were used together.

Research limitations/implications

The paper is based on findings from a fully synthetic 5 W-30 A5 multi-grade engine lubrication oil collected after driving approximately 12.000 km.

Practical implications

The results are significant, as they suggest practical regeneration of used engine oil is achievable. Additionally, blending fresh oil with reclaimed used engine oil in a 1:1 ratio reduced wear loss by over 10% compared to fresh oil.

Social implications

Reusing used engine oils can reduce their environmental impact and bring economic benefits.

Originality/value

This study showed that the properties of UEO can be enhanced using the solvent extraction-adsorption method. Furthermore, the study provided valuable insights into the metal concentrations in engine oil samples and their impact on lubrication performance. The order of the number of the grooves quantity and the possibility of the observed scuffing region trend relative to the samples was UEO > 5W-30 fresh oil > Treated oil sample with the adsorbent cement and celite together.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0209/

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Article
Publication date: 8 April 2020

Ebere Ume Kalu, Uchenna Florence Nwafor, Chinwe R. Okoyeuzu and Vincent A. Onodugo

The purpose of this study is to investigate the energy–growth linkage in sub-Saharan Africa (SSA), with emphasis on real sectors’ contribution to aggregate growth using dynamic…

188

Abstract

Purpose

The purpose of this study is to investigate the energy–growth linkage in sub-Saharan Africa (SSA), with emphasis on real sectors’ contribution to aggregate growth using dynamic panel estimation techniques that are practically and conceptually superior to the static models.

Design/methodology/approach

Dynamic panel econometric techniques pooled mean group, mean group and dynamic fixed effect were used to investigate the linkage among energy consumption, real sector value added and economic growth from 1967 to 2016 in 48 SSA countries.

Findings

A strong empirical evidence in favor of energy dependence and growth hypothesis in the investigated SSA countries was found. The finding that real sector value added and overall growth rate adjust reasonably to the shocks and dynamics of the energy consumption variables makes energy consumption an enabler for growth. This indicates that well thought-out and implemented energy development policy will not only increase energy consumption but also elicit multi-sectoral growth while addressing the obvious energy deficiency in the SSA region.

Research limitations/implications

It is also important to note the policy implications of the high adjustment profiles indicated by the error correction representations. All the speeds of adjustment of the three models denominated in time are slightly above a year and are all within predictable limits (they fall below unity or 100%). We found that when agriculture value added, manufacturing value added and overall economic growth rate in our SSA panel estimation exceed equilibrium levels as a result of deviations arising from energy related variables, downward adjustments at 66%, 62% and 78% per year, respectively, take place.

Practical implications

The study indicates that well thought-out and implemented energy development policy will not only increase energy consumption but also elicit multi-sectoral growth while addressing the obvious energy deficiency in the SSA region.

Social implications

Much as this study has made some addition to the literature on energy-growth nexus in the SSA region, which undoubtedly is an unveiling of economic forces in a collection of developing and energy deficient economies, it will be of great research significance if the form and style of this study is adopted for other economic blocs in the shapes and sizes of the SSA region.

Originality/value

This study ensured currency of data, novelty of approach and disaggregated energy consumption into emerging sources, traditional sources and geographical access.

Details

International Journal of Energy Sector Management, vol. 14 no. 5
Type: Research Article
ISSN: 1750-6220

Keywords

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Book part
Publication date: 16 February 2006

Caner Bakir

The 17 December 2004 was a turning point in both Turkish and European history: The European Council followed the European Commission's recommendation and approved the opening of…

Abstract

The 17 December 2004 was a turning point in both Turkish and European history: The European Council followed the European Commission's recommendation and approved the opening of accession negotiations with Turkey, which commenced on 3 October 2005. The goal of accession to the European Union (EU) has become one of the main driving forces for broadly defined legal, political, economic, and financial reforms in Turkey.2

Details

Emerging European Financial Markets: Independence and Integration Post-Enlargement
Type: Book
ISBN: 978-0-76231-264-1

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