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Article
Publication date: 5 September 2016

Lyaysan Ildusovna Garipova, Andrei Sergeevich Batrakov, Alexander Nikolaevich Kusyumov, Sergey Anatolievich Mikhaylov and George Barakos

The design of main rotor blade tips is of interest to helicopter manufactures since the tip details affect the performance and acoustics of the rotor. The paper aims to…

Abstract

Purpose

The design of main rotor blade tips is of interest to helicopter manufactures since the tip details affect the performance and acoustics of the rotor. The paper aims to discuss this issue.

Design/methodology/approach

In this paper, computation fluid dynamics is used to simulate the flow around hovering helicopter blades with different tip designs. For each type of blade tip a parametric study on the shape is also conducted for comparison calculations were performed the constant rotor thrust condition. The collective pitch and the cone angles of the blades were determined by at an iterative trimming process.

Findings

Analysis of the distributed blade loads shows that the tip geometry has a significant influence on aerodynamics and aeroacoustics especially for stations where blade loading is high.

Originality/value

The aeroacoustic characteristics of the rotors were obtained using Ffowcs Williams-Hawkings equations.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 7
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 5 September 2016

George Zografakis and George Barakos

This paper aims to explore the potential of transition prediction methods for modelling transitional shock wave/boundary layer interactions. The study is fuelled by the…

Abstract

Purpose

This paper aims to explore the potential of transition prediction methods for modelling transitional shock wave/boundary layer interactions. The study is fuelled by the strong interest of researchers and airframe manufacturers in reducing the drag of vehicles flying at transonic speeds. The principle of drag reduction via flow laminarity is valid, provided there is no need for the flow to sustain large pressure gradients or shocks. This is true, as laminar boundary layers are less resistant to flow separation.

Design/methodology/approach

It is, therefore, worthwhile to assess the performance of CFD methods in modelling laminar boundary layers that can be tripped to turbulent just before an interaction with a shock. In this work, the CFD solver of Liverpool University is used. The method is strongly implicit, and, for this reason, the implementation of intermittency-based models requires special attention. The Navier–Stokes equations, the transport equations of the kinetic energy of turbulence and the turbulent frequency are inverted at the same time as the transport equations for the flow intermittency and the momentum thickness Reynolds number.

Findings

The result is stable and robust convergence even for complex three-dimensional flow cases. The method is demonstrated for the flow around the V2C section of the TFAST EU, F7 project. The results suggest that the intermittency-based model captures the fundamental physics of the interaction, but verification and validation are needed to ensure that accurate results can be obtained. For this reason, comparisons with the TFAST experiments is put forward as a means of establishing confidence in the transition prediction tools used for shock/boundary layer interaction simulation.

Research limitations/implications

At the moment, experimental data for transonic transitional buffet are not yet available, although this will change in the near future.

Practical implications

The required CPU time is neither insignificant not prohibitive for routine computations.

Social implications

Reducing aircraft drag without compromising on stall characteristics will result in lower fuel consumption and contribute to a greener and more economic flight for passengers.

Originality/value

To the authors’ knowledge, this is the first time that transitional buffet has been addressed.

Details

Aircraft Engineering and Aerospace Technology, vol. 88 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

Content available
Article
Publication date: 21 March 2008

John H. Barnes

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 80 no. 2
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 5 August 2019

Nelson Waweru, Musa Mangena and George Riro

This paper aims to investigate corporate internet reporting (CIR) by Kenyan and Tanzanian listed companies and whether the level of CIR is related to corporate governance…

Abstract

Purpose

This paper aims to investigate corporate internet reporting (CIR) by Kenyan and Tanzanian listed companies and whether the level of CIR is related to corporate governance structures.

Design/methodology/approach

The authors collect data over a four-year period from companies listed on the Nairobi Securities Exchange and the Dar es Salaam Securities Exchange. Panel data models (random effects) are used for the analysis.

Findings

The results indicate that the level of CIR in both countries is high, but the highest in Kenya. The authors find that CIR increases with foreign ownership, audit committee independence and financial expertise but decreases with domestic ownership concentration. They also show that the effects of ownership concentration are moderated by country-specific factors. Overall, the results demonstrate that effective governance structures may lead to higher levels CIR in sub-Saharan Africans.

Originality/value

This study extends, as well as contributes to the existing literature by the examining the corporate governance-disclosure nexus relating to CIR in sub-Saharan Africa. These findings have policy implications for African countries looking to attract foreign investment.

Details

Corporate Governance: The International Journal of Business in Society, vol. 19 no. 4
Type: Research Article
ISSN: 1472-0701

Keywords

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Article
Publication date: 4 November 2019

Issal Haj Salem, Salma Damak Ayadi and Khaled Hussainey

The purpose of this paper is to investigate the potential influence of corporate governance mechanisms on risk disclosure quality in Tunisia.

Abstract

Purpose

The purpose of this paper is to investigate the potential influence of corporate governance mechanisms on risk disclosure quality in Tunisia.

Design/methodology/approach

The authors examine 152 annual reports of Tunisian non-financial-listed firms during 2008–2013, and use the manual content analysis method to measure the risk disclosure quality.

Findings

The authors find that the quality of risk disclosure in Tunisian companies is relatively low, and also find that the quality of risk disclosure is positively associated with institutional ownership, board independence, the presence of women on the board, the presence of family members on the board and the independence of audit committee. Managerial ownership has a negative effect on risk disclosure quality. Finally, the authors find that the revolution decreases the influence of concentration ownership, government ownership, family ownership and audit committee size on risk disclosure quality.

Originality/value

Using a comprehensive set of corporate governance mechanisms and a new measure for risk disclosure quality in Tunisia, the authors provide the first empirical evidence on the impact of corporate governance mechanisms on risk disclosure quality in a developing country. The study has theoretical and practical implications for both developed and developing countries.

Details

Journal of Accounting in Emerging Economies, vol. 9 no. 4
Type: Research Article
ISSN: 2042-1168

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Article
Publication date: 5 June 2017

Michail Nerantzidis and Anastasios Tsamis

The purpose of this study is to review the prior empirical studies that investigate the corporate governance (CG) determinants and provide a synopsis, and explore the main…

Abstract

Purpose

The purpose of this study is to review the prior empirical studies that investigate the corporate governance (CG) determinants and provide a synopsis, and explore the main factors that drive the level of CG disclosure in the Greek context.

Design/methodology/approach

The authors perform an extensive review of the relevant literature and identify 24 papers that use various potential factors. Afterwards, the authors construct two different GC indices to investigate these potentials, and the authors conduct multiple regression analysis to identify and explain these determinants.

Findings

The empirical analysis shows that large Greek listed firms are more likely to disclose more CG information in the CG statement. In addition, the analysis shows statistically significant association with performance-related variables (such as Tobin’s Q and liquidity) and CG-related variables (such as independent members, board meetings and women on board).

Research limitations/implications

The results of the study support theoretical arguments that Greek listed firms disclose CG information not only to fulfill task-related requirements but also to be perceived as social and legitimate.

Originality/value

To the best of the authors’ knowledge, this is the first study that provides a synopsis of the prior literature in CG determinants, while it goes one step further by using the majority of the potential factors that have been used so far. Moreover, this study uses a multi-theoretical framework to address theoretical development, an approach that generates an outline of fruitful directions for future research.

Details

Corporate Governance: The International Journal of Business in Society, vol. 17 no. 3
Type: Research Article
ISSN: 1472-0701

Keywords

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Article
Publication date: 13 April 2020

Noha Elberry and Khaled Hussainey

The authors examine the impact of corporate investment efficiency on corporate voluntary disclosure for a sample of UK non-financial companies.

Abstract

Purpose

The authors examine the impact of corporate investment efficiency on corporate voluntary disclosure for a sample of UK non-financial companies.

Design/methodology/approach

The authors use a sample of FTSE All-Share firms for the period of 2007–2014. Disclosure scores are collected from Corporate Financial Information Environment (CFIE). They follow Biddle et al. (2009) and Chen et al. (2011) in measuring corporate investment efficiency.

Findings

The authors find that high level of performance-related disclosure is associated with high level of corporate investment efficiency, while high level of good news information is associated with low level of corporate investment efficiency. They also find evidence on a bidirectional relation between disclosure and corporate investment efficiency.

Research limitations/implications

The authors’ findings would be of importance to stakeholders and corporations. Stakeholders' investment decisions could be facilitated by understanding the disclosures provided by their firms and how these firms' performance is presented. Corporations become aware of the language which must be used to signal their performance.

Practical implications

Corporations become aware of the language which must be used in their disclosures. As firms may reflect their efficient investments but not in the form of good news in order to avoid revealing their competitive advantage to competitors.

Originality/value

This paper adds to disclosure studies by introducing a new variable, corporate investment efficiency, as a determinant of corporate disclosure practice.

Details

Journal of Applied Accounting Research, vol. 21 no. 2
Type: Research Article
ISSN: 0967-5426

Keywords

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Article
Publication date: 20 June 2020

Amina Buallay, Ammar Abdulla Al Hawaj and Allam Hamdan

In the Gulf Cooperative Council (GCC) countries, the integrated reporting (IR) concept has attracted considerable attention from banks. In as much as IR is not a legal…

Abstract

Purpose

In the Gulf Cooperative Council (GCC) countries, the integrated reporting (IR) concept has attracted considerable attention from banks. In as much as IR is not a legal requirement anywhere in the GCC, however, the incidence of disclosure by banks across the GCC varies considerably and asymmetries exist in the content of disclosure released by banks within, as well as across, these jurisdictions. This study aims to examine the relationship between IR disclosure and financial, operational and market performance in both Islamic and conventional banks.

Design/methodology/approach

This study examines five years (2012-2016) of IR from 59 banks in GCC countries with 295 observations. The integrated report index (IRI), as the independent variable, is regressed separately against three performance indicators [return on assets, return on equity and Tobin’s Q (TQ)] as dependent variables. In addition, the following two types of control variables are inserted in the regression equations in this study: macroeconomic (two indicators) and bank characteristics (three indicators).

Findings

The findings elicited from the empirical results demonstrate that, on the one hand, IR in conventional banks positively affects market performance, while negatively affecting operational and financial performance. On the other hand, the results for Islamic banks show that IR negatively affects market performance, with no discernible effect on neither financial nor operational performance. In the GCC banking sector, for the most, empirical results conflict with expectations implied by signaling theory and capital need theory. From this study, evidence suggests that GCC bank performance would not improve were IR disclosure rendered mandatory. However, that conclusion is stronger with respect to Islamic than with respect to conventional banks in the region.

Originality/value

The study provides insights into the effect of voluntary disclosure of IR as gauged by various measures of performance across Islamic and conventional banks located in a range of GCC countries. This study accordingly provides perspective on the extent to which IR can and does play a role in contributing to bank performance.

Details

Journal of Islamic Marketing, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1759-0833

Keywords

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Article
Publication date: 6 January 2020

Saed Ahmed Sulub, Zalailah Salleh and Hafiza Aishah Hashim

This paper aims to identify the effects of some corporate governance (CG) mechanisms and Shariah Supervisory Board (SSB) strength on the voluntary use of internal audit…

Abstract

Purpose

This paper aims to identify the effects of some corporate governance (CG) mechanisms and Shariah Supervisory Board (SSB) strength on the voluntary use of internal audit function (IAF) by Islamic banks in Sudan.

Design/methodology/approach

Based on Agency and Stakeholder Theories, this paper hypothesizes that IAF is likely used by Islamic banks with strong CG and Shariah governance systems. To test these hypotheses, we examine the annual reports of 14 Sudanese banks for a period of five years following the global financial crisis in 2008, using logistic regression analysis.

Findings

This paper found that IAF is likely used by Islamic banks with higher CG disclosure (CGD) and strong SSB. While the findings showed that the audit committee and IAF are likely used as substitutes, this paper also indicated that there is a negative association between levels of Unrestricted Investment Account Holders’ (UIAH) ownership and the use of IAF. However, the evidence of this study did not find any impact for the board of directors’ strength on the use of IAF.

Research limitations/implications

There may be better measures for some variables in the study model. Additionally, the restriction of the study sample to Sudanese banks may limit the generalization of the results. Therefore, future studies may refine the model and expand the sample to Islamic banks in other countries.

Practical implications

This paper highlights the importance of IAF for Shariah governance in Islamic banks. Moreover, the insignificant association between the use of IAF and the strength of board of directors has important implications for the board’s effectiveness in Islamic banks.

Originality/value

This is the first study to investigate the factors associated with the use of IAF by Islamic banks.

Details

Journal of Islamic Accounting and Business Research, vol. 11 no. 1
Type: Research Article
ISSN: 1759-0817

Keywords

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Article
Publication date: 14 May 2020

Fahad P and Nidheesh KB

This paper aims to undertake an empirical investigation on firm characteristics determining corporate social responsibility (CSR) disclosure and its subcategories such as…

Abstract

Purpose

This paper aims to undertake an empirical investigation on firm characteristics determining corporate social responsibility (CSR) disclosure and its subcategories such as environmental, social and governance disclosures.

Design/methodology/approach

The sample consisted of listed companies in BSE 500 index for a period of 10 years from 2007 to 2016. Panel data regression method is used for the analysis. Seven variables are analyzed, namely, firm age, financial leverage, firm size, foreign ownership, promoter ownership, export performance, innovation and firm popularity.

Findings

The result shows that firm age and financial leverage are positively influencing CSR, environmental and social disclosure score but both are negatively influencing governance score. Firm size is positively associated with all four disclosure scores. Among ownership variables, foreign ownership shows a positive influence and promoters ownership shows a negative influence towards CSR, environment and social disclosures. No association is found between both ownership variables and governance disclosure score. Further analysis also finds that there is a difference in this relationship during crisis period.

Research limitations/implications

The study focuses only on listed companies in Indian capital market. In terms of implication, theoretical bases discussed in the literature review and hypotheses development are mostly validated.

Practical implications

The findings are important for the firm, stakeholders and policymakers. A firm may think about appointing experts in CSR to spend the amount wisely and improve CSR disclosure to compete in the international market; stakeholders have to pressure the firm to provide more CSR disclosure and for policymakers this study study provides useful inputs to design legal framework on CSR.

Originality/value

The measurement of CSR disclosure using environmental, social and governance (ESG) score is novel in Indian context, even though the methodology is often used in literature.

Details

Journal of Indian Business Research, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1755-4195

Keywords

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