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1 – 10 of over 6000
Article
Publication date: 1 April 1996

M.S. Ibrahim, R.M. Mohsen and S.M. El‐Sawy

Reports on the preparation of some organic corrosion inhibitors, carried out by the reaction of epoxidized linseed oil free fatty acids with different aliphatic amines under the…

Abstract

Reports on the preparation of some organic corrosion inhibitors, carried out by the reaction of epoxidized linseed oil free fatty acids with different aliphatic amines under the effect of γ‐ray irradiation. Notes that chemical and instrumental methods were used for identification of the reaction products and that the prepared inhibitors were tested for corrosion protection of steel surfaces by incorporating them in some chlorinated rubber varnishes. Reports that the physical, chemical and corrosion protective properties of the varnish films were studied. Concludes that the prepared inhibitors can be used in small quantities to provide varnishes of excellent adhesion and superior protective properties. Contends, also, that increase of the radiation dose during preparation of the inhibitors and/or during the drying process of the varnish films increases the protective properties of the formed films.

Details

Anti-Corrosion Methods and Materials, vol. 43 no. 4
Type: Research Article
ISSN: 0003-5599

Content available
Article
Publication date: 11 October 2021

MyoJung Cho and Salma Ibrahim

This study aims to examine whether chief executive officer (CEO) pay-performance sensitivity to shareholder wealth is related to the use of non-financial performance measures in…

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Abstract

Purpose

This study aims to examine whether chief executive officer (CEO) pay-performance sensitivity to shareholder wealth is related to the use of non-financial performance measures in incentive contracts.

Design/methodology/approach

Using hand-collected performance measure data in a sample of S&P 500 firms across the period 1994–2010, this study investigates the sensitivity of CEO bonus and cash pay to shareholder wealth of firms that use non-financial performance (NFPM) measures of varying types and contractual weights in their bonus contracts along with financial measures (NFPM firms) in comparison to that of firms using financial measures only (FPM firms).

Findings

This study finds evidence that the pay-performance sensitivity is stronger in NFPM firms than in FPM firms. These results are driven by the use of CEO individual goals and operational efficiency. Furthermore, when using environmental, social and governance factors, the pay-performance sensitivity is stronger in terms of accounting performance only. This study also finds that using NFPM enhances pay-performance sensitivity more as their contractual weights increase and as financial risk increases.

Practical implications

These findings are important to stakeholders, and especially regulators in understanding incentive effects of alternative performance measures. This study also sheds light on what types of non-financial measures are better in helping firms align CEOs’ incentives to shareholders’ interests.

Originality/value

This study contributes to prior research on benefits of non-financial information within the context of executive compensation. This study presents original results about the effects of contractual weights of non-financial measures and financial risk on CEO pay-performance sensitivity. This study also presents new insights regarding how different types of non-financial measures affect CEO pay-performance sensitivity.

Details

Journal of Financial Reporting and Accounting, vol. 20 no. 2
Type: Research Article
ISSN: 1985-2517

Keywords

Article
Publication date: 17 August 2018

K. Suneetha, S.M. Ibrahim and G.V. Ramana Reddy

The purpose of this paper is to investigate the steady 2D buoyancy effects on MHD flow over a permeable stretching sheet through porous medium in the presence of suction/injection.

Abstract

Purpose

The purpose of this paper is to investigate the steady 2D buoyancy effects on MHD flow over a permeable stretching sheet through porous medium in the presence of suction/injection.

Design/methodology/approach

Similarity transformations are employed to transform the governing partial differential equations into ordinary differential equations. The transformed equations are then solved numerically by a shooting technique.

Findings

The working fluid is examined for several sundry parameters graphically and in tabular form. It is observed that with an increase in magnetic field and permeability of porous parameter, velocity profile decreases while temperature and concentration enhances. Stretching sheet parameter reduces velocity, temperature and concentration, whereas it increases skin friction factor, Nusselt number and Sherwood number.

Originality/value

Till now no numerical studies are reported on the effects of heat source and thermal radiation on MHD flow over a permeable stretching sheet embedded in porous medium in the presence of chemical reaction.

Details

Multidiscipline Modeling in Materials and Structures, vol. 14 no. 5
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 4 September 2019

K. Suneetha, S.M. Ibrahim and G.V. Ramana Reddy

The purpose of this paper is to address the combined effects of thermal radiation and chemical reaction on steady MHD mixed convective heat and mass transfer flow past a vertical…

Abstract

Purpose

The purpose of this paper is to address the combined effects of thermal radiation and chemical reaction on steady MHD mixed convective heat and mass transfer flow past a vertical surface under the influence of Joule and viscous dissipation.

Design/methodology/approach

The governing system of partial differential equations is transformed to dimensionless equations using dimensionless variables. The dimensionless equations are then solved analytically using perturbation technique.

Findings

With the help of graphs, the effects of the various important parameters entering into the problem on the dimensionless velocity, dimensionless temperature and dimensionless concentration fields within the boundary layer are discussed. The authors noticed that the velocity increases with an increase in the porosity parameter. An increase in the Prandtl number Pr, decreases the velocity and the temperature field. An increase in the radiation parameter, decreases the velocity and the temperature field. Also the effects of the pertinent parameters on the skin-friction coefficient and rates of heat and mass transfer in terms of the Nusselt and Sherwood numbers are presented numerically in tabular form.

Originality/value

To the best of the authors’ knowledge, recent this work has not been finished by any other researchers.

Details

Multidiscipline Modeling in Materials and Structures, vol. 16 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 15 July 2022

Saeed Akbar, Shehzad Khan, Zahoor Ul Haq and Muhammad Ibrahim Khan

This study aims to compare capital structure determinants' effect on the leverage levels of Shariah-compliant (SC) and noncompliant (NC) firms in Pakistan. This study also…

Abstract

Purpose

This study aims to compare capital structure determinants' effect on the leverage levels of Shariah-compliant (SC) and noncompliant (NC) firms in Pakistan. This study also estimates and compares the capital structure adjustment speed for both firm types.

Design/methodology/approach

Based on the Karachi Meezan Index screening criterion, a balanced panel of 117 SC and 68 NC firms listed on the Pakistan Stock Exchange from 2008 to 2018 was constituted. This study used the generalized method of moments to identify the significant determinants of capital structure and estimate the speed of adjustment. In addition, the F-test was used to check whether the effect of the determinants on the leverage is same for SC and non-SC firms.

Findings

The authors found that different determinants affect both firm types' leverage levels (book and market) differently. The authors also found that the adjustment speed of SC firms toward their target leverage ratio is slower than their NC peers. Lastly, significant variation was observed in the results under different screening criteria.

Research limitations/implications

This study fills the literature gap by providing a comprehensive comparison of the capital structure decisions of the SC and non-SC firms. Because this study is limited to Pakistan, generalizability would be an issue.

Practical implications

This study will guide the management of SC and non-SC firms about which factors are reliably important in choosing their capital structure. The findings also call for bringing harmony in the different Shariah screening criteria being in practice.

Originality/value

To the best of the authors’ knowledge, this is the first comparative study that identifies the significant capital structure determinants for SC and NC firms and investigates their effect on the leverage of both firm types. By testing joint hypotheses of same relationship, this study seeks to determine if, because of Shariah restrictions, the capital structure determinants of SC firms are similar to NC firms or they exhibit different behavior. The authors also repeat their analysis using other prominent screening criteria to assess the consistency of their results.

Details

International Journal of Islamic and Middle Eastern Finance and Management, vol. 16 no. 2
Type: Research Article
ISSN: 1753-8394

Keywords

Abstract

Purpose

This paper aims to achieve two main objectives. First, to introduce to the literature a new versatile active building block, namely, voltage differencing differential voltage current conveyor (VD-DVCC) for analog signal processing applications. Second, to design a novel electronically tunable mixed-mode universal filter. The designed filter provides low-pass, high-pass, band-pass, band-reject and all-pass responses in voltage-mode (VM), current-mode (CM), trans-impedance-mode (TIM) and trans-admittance-mode (TAM).

Design/methodology/approach

The proposed filter uses two VD-DVCCs, three resistors and two capacitors. All the capacitors used are grounded, which is advantageous from the monolithic integration point of view. The VD-DVCC is designed and validated in Cadence software using CMOS 0.18 µm process design kit from Silterra Malaysia at a supply voltage of ±1 V.

Findings

The proposed novel filter enjoys many attractive features including as follows: the ability to operate in all four modes, no requirement of capacitive matching, tunability of quality factor (Q) independent of pole frequency, availability of both inverting and non-inverting outputs for VM and TIM mode, high output impedance explicit current output for CM and TAM, no requirement for double/negative input signals (voltage/current) for response realization and low active and passive sensitivities. The filter is designed for a pole frequency of 5.305 MHz. The obtained results bear a close resemblance with the theoretical findings.

Originality/value

The proposed novel filter structure requires a minimum number of active and passive components and provides operation in all four operating modes. The filter will find application in structures of mixed-mode systems.

Details

Circuit World, vol. 48 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 23 November 2018

Gangadhar Kotha, Keziya Kukkamalla and S.M. Ibrahim

The purpose of this paper is to examine the magneto hydrodynamic flow and heat transfer of nanofluids over a permeable wedge based on engine oil which is under the effects of…

Abstract

Purpose

The purpose of this paper is to examine the magneto hydrodynamic flow and heat transfer of nanofluids over a permeable wedge based on engine oil which is under the effects of thermal radiation and convective heating.

Design/methodology/approach

The equations governing the flow are transformed into differential equations by applying similarity transformations. Keller box method is used to bring out the numerical solution.

Findings

The discovery interprets that temperature as well as the velocity of Ag-engine oil nanofluids are more noticeable than Cu-engine oil nanofluids. Thermal boundary layer increases for radiation parameter as well as Biot number. Fluctuations of co-efficient of drag skin friction as well heat transfer rate at the wall are also tested.

Originality/value

Till now, no numerical studies are reported on the heat transfer enhancement of the permeable wedge under thermal radiation on engine oil nanofluid flow by considering convective heating.

Details

Multidiscipline Modeling in Materials and Structures, vol. 15 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 19 September 2018

O.K. Koriko, I.L. Animasaun, A.J. Omowaye and T. Oreyeni

The purpose of this paper is to consider the problem of thermal destratification facing engineers and scientists during the motion of fluids which consist of rigid and randomly…

172

Abstract

Purpose

The purpose of this paper is to consider the problem of thermal destratification facing engineers and scientists during the motion of fluids which consist of rigid and randomly oriented particles suspended in a viscous medium under the influence of Lorentz force. This paper provides an insight into the non-linear transfer of thermal radiation within the boundary layer.

Design/methodology/approach

Similarity transformation and parameterization of the non-linear partial differential equation are carried out. The approximate analytical solution of the governing equation which models the free convective flow of strong and weak concentration of micro-elements in a micropolar fluid over a vertical surface is presented.

Findings

It is observed that the velocity and temperature distribution are decreasing properties of thermal stratification parameter St. Maximum local skin friction coefficients are ascertained at an epilimnion level (St=0) when the magnitude of thermal radiation is small. Thermal stratification parameter has no significant effect on the temperature distribution in the flow near a free stream.

Originality/value

The relationship between stratification of temperature and the transfer of thermal energy during the problem of thermal destratification facing engineers and scientist during the motion of fluids which consist of rigid and randomly oriented particles suspended in a viscous medium under the influence of Lorentz force is unravelled in this paper.

Details

Multidiscipline Modeling in Materials and Structures, vol. 15 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 30 September 2022

Hend Monjed, Salma Ibrahim and Bjørn N. Jørgensen

The purpose of this study is to examine the association between two reporting mechanisms used by managers to communicate risk information to the capital market: risk disclosure…

Abstract

Purpose

The purpose of this study is to examine the association between two reporting mechanisms used by managers to communicate risk information to the capital market: risk disclosure and earnings smoothing.

Design/methodology/approach

This study juxtaposes two competing hypotheses, the “opportunistic” and the “signaling”, and empirically investigates whether one dominates the other for a sample of large UK firms for the period 2005–2015. This study also uses the global financial crisis as an arguably exogenous shock on overall risk in the economy to investigate its effect on managers' joint use of textual risk disclosures and earnings smoothing.

Findings

This study finds that risk disclosure and earnings smoothing are negatively associated. This finding supports that managers with incentives to mask the firm’s true underlying risk through smoothing earnings provide lower levels of risk-related disclosures. This study documents that the trade-off between risk disclosure and earnings smoothing is more pronounced during the global financial crisis period than before and after the crisis period. Further, this study demonstrates a more negative association for firms with higher volatility of cash flows. This negative association is robust to various model specifications, additional corporate governance related controls and an alternative measure of earnings smoothing.

Originality/value

The findings provide new empirical evidence about the association between risk disclosure and earnings smoothing and support the opportunistic hypothesis, especially when firms are faced with increased risk.

Details

Review of Accounting and Finance, vol. 21 no. 5
Type: Research Article
ISSN: 1475-7702

Keywords

Article
Publication date: 8 May 2018

Fatma A. Mohamed, Saadia A. Abd El-Megied, Mahmoud S. Bashandy and Hassan M. Ibrahim

This study aims to synthesise and characterise new reactive dyes based on thiazole derivatives which act as chromophoric moieties. These dyes were applied to cotton fabric…

Abstract

Purpose

This study aims to synthesise and characterise new reactive dyes based on thiazole derivatives which act as chromophoric moieties. These dyes were applied to cotton fabric, resulting in the dyed fabrics exhibiting good colour strength, light fastness and other fastness properties. The antibacterial activity of the dyed cotton fabric was evaluated against gram-negative and gram-positive bacteria.

Design/methodology/approach

The dyes were synthesised in two steps. First, the coupling compound was formed by adding H-acid solution to cyanuric chloride in an ice bath at pH 5 then adding 4-aminobenzenesulphonic acid portion-wise at room temperature and at pH 6-7. Second, different diazonium salts 4-phenylthiazol-2-amine (2a) and 4-(4-methoxyphenyl) thiazol-2-amine (2b) were coupled with the coupling compound at pH 5. The resultant monochlorotriazine (MCT)-reactive dyes (6a, 6b) were formed. The synthesised dyes were applied onto cotton fabric under typical exhaust dyeing conditions and their dyeing properties were investigated.

Findings

High antimicrobial activity, dye exhaustion and fixation yield on cotton fabric were recorded for each dye. All dyes showed high stability against washing, rubbing, perspiration and light fastness.

Research limitations/implications

Dyeing of cotton fabric with these dyes which have higher fastness, higher exhaustion and higher antibacterial activity is considered one of the most important reactive dyes species.

Practical implications

The preparation procedure showed the synthesis of the novel MCT-reactive dyes derived from thiazole derivatives followed by the application of these dyes on cotton fabrics.

Social implications

Use of reactive dyes will bring a number of benefits to society including higher fastness and higher antibacterial activity so, and these dyes can be used for dyeing cotton.

Originality/value

In this work, the new reactive dyes derived from thiazole derivatives were synthesised and their structures were confirmed by the analytical and spectral data. Such compounds are considered to be excellent reactive dyes with different colour shades and higher antibacterial activity.

Details

Pigment & Resin Technology, vol. 47 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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