Search results
1 – 10 of over 6000M.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.
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…
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
Keywords
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
Keywords
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
Keywords
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
Keywords
Mohammad Faseehuddin, Norbert Herencsar, Musa Ali Albrni, Sadia Shireen and Jahariah Sampe
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
Keywords
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
Keywords
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…
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
Keywords
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
Keywords
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