Search results

1 – 10 of 672
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 30 September 2024

Lorenzo Ligorio, Fabio Caputo and Andrea Venturelli

The growing interest in sustainability reporting by management scholars is leading to new research fields. Among the different actors involved in non-financial disclosures, recent…

120

Abstract

Purpose

The growing interest in sustainability reporting by management scholars is leading to new research fields. Among the different actors involved in non-financial disclosures, recent research is paying attention to public–private hybrid organisations. This study explores the main focus and critique of current and past literature on public–private hybrids and sustainability reporting.

Design/methodology/approach

To explore the recent field of sustainability reporting in public–private hybrids, this study adopts a structured literature review on studies collected from the scientific platforms Scopus and Web of Science.

Findings

Findings revealed a young and growing field of research. Also, it emerged how more profound attention is being paid to the features and drivers of sustainability reporting in the public–private sector, along with a stimulus for further research on new reporting frameworks.

Research limitations/implications

Considering the novelty of the research field, the collection of analysed studies was very limited. Moreover, grey literature was not incorporated into the research. In addition, only two sources of data were considered.

Practical implications

This study includes different implications regarding sustainability reporting in public–private hybrids, emphasizing transparency, accountability and the need for further research and adoption of external assurance.

Originality/value

Because of the novelty of the research field, this is the first study to focus on literature that addresses the relationship between sustainability reporting and public–private entities. Furthermore, using a structured literature review has provided a profound view of the published literature.

Details

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

Keywords

Access Restricted. View access options
Article
Publication date: 21 August 2013

B. Adebayo and B. Adetula

This work deals with the investigation of physical and mechanical properties of selected rocks for condition of drilling categorization. Rock samples collected from five drilling…

512

Abstract

This work deals with the investigation of physical and mechanical properties of selected rocks for condition of drilling categorization. Rock samples collected from five drilling locations were tested in the laboratory for uniaxial compressive strength, tensile strength, and Drilling Rate Index (DRI) using 1,100 kN compression machine, point load tester and miniature drill. Similarly, hardness, brittleness, Rock Abrasivity Index (RAI), penetration rate and bit wear rate were determined. The results showed that uniaxial compressive strength, tensile strength and Drilling Rate Index varied from 47.78 - 111.11 MPa, 8.09 - 19.44 MPa, and 20 - 52 respectively. The Nast point system chart was used to classify the rocks into drilling conditions. The drilling classification shows that the drilling condition of the rocks varied from slow to fast. The drillability characteristics of the rocks vary from extremely low to medium as specified by the Drilling rate Index (DRI). It was concluded that uniaxial compressive strength, texture and grain size, drilling rate index and Equivalent Quartz Content (EQC) are important parameters affecting drilling condition of the rocks.

Details

World Journal of Engineering, vol. 10 no. 4
Type: Research Article
ISSN: 1708-5284

Keywords

Access Restricted. View access options
Article
Publication date: 6 January 2021

Navya Thirumaleshwar Hegde, V. I. George, C. Gurudas Nayak and Aldrin Claytus Vaz

This paper aims to provide a mathematical modeling and design of H-infinity controller for an autonomous vertical take-off and landing (VTOL) Quad Tiltrotor hybrid unmanned aerial…

402

Abstract

Purpose

This paper aims to provide a mathematical modeling and design of H-infinity controller for an autonomous vertical take-off and landing (VTOL) Quad Tiltrotor hybrid unmanned aerial vehicles (UAVs). The variation in the aerodynamics and model dynamics of these aerial vehicles due to its tilting rotors are the key issues and challenges, which attracts the attention of many researchers. They carry parametric uncertainties (such as non-linear friction force, backlash, etc.), which drives the designed controller based on the nominal model to instability or performance degradation. The controller needs to take these factors into consideration and still give good stability and performance. Hence, a robust H-infinity controller is proposed that can handle these uncertainties.

Design/methodology/approach

A unique VTOL Quad Tiltrotor hybrid UAV, which operates in three flight modes, is mathematically modeled using Newton–Euler equations of motion. The contribution of the model is its ability to combine high-speed level flight, VTOL and transition between these two phases. The transition involves the tilting of the proprotors from 90° to 0° and vice-versa in 15° intervals. A robust H-infinity control strategy is proposed, evaluated and analyzed through simulation to control the flight dynamics for different modes of operation.

Findings

The main contribution of this research is the mathematical modeling of three flight modes (vertical takeoff–forward, transition–cruise-back, transition-vertical landing) of operation by controlling the revolutions per minute and tilt angles, which are independent of each other. An autonomous flight control system using a robust H-infinity controller to stabilize the mode of transition is designed for the Quad Tiltrotor UAV in the presence of uncertainties, noise and disturbances using MATLAB/SIMULINK. This paper focused on improving the disturbance rejection properties of the proposed UAV by designing a robust H-infinity controller for position and orientation trajectory regulation in the presence of uncertainty. The simulation results show that the Tiltrotor achieves transition successfully with disturbances, noise and uncertainties being present.

Originality/value

A novel VTOL Quad Tiltrotor UAV mathematical model is developed with a special tilting rotor mechanism, which combines both aircraft and helicopter flight modes with the transition taking place in between phases using robust H-infinity controller for attitude, altitude and trajectory regulation in the presence of uncertainty.

Details

International Journal of Intelligent Unmanned Systems, vol. 9 no. 3
Type: Research Article
ISSN: 2049-6427

Keywords

Access Restricted. View access options
Article
Publication date: 4 September 2019

Navya Thirumaleshwar Hegde, V.I. George, C. Gurudas Nayak and Kamlesh Kumar

The purpose of this paper is to give reviews on the platform modeling and design of a controller for autonomous vertical take-off and landing (VTOL) tilt rotor hybrid unmanned…

1530

Abstract

Purpose

The purpose of this paper is to give reviews on the platform modeling and design of a controller for autonomous vertical take-off and landing (VTOL) tilt rotor hybrid unmanned aerial vehicles (UAVs). Nowadays, UAVs have experienced remarkable progress and can be classified into two main types, i.e. fixed-wing UAVs and VTOL UAVs. The mathematical model of tilt rotor UAV is time variant, multivariable and non-linear in nature. Solving and understanding these plant models is very complex. Developing a control algorithm to improve the performance and stability of a UAV is a challenging task.

Design/methodology/approach

This paper gives a thorough description on modeling of VTOL tilt rotor UAV from first principle theory. The review of the design of both linear and non-linear control algorithms are explained in detail. The robust flight controller for the six degrees of freedom UAV has been designed using H-infinity optimization with loop shaping under external wind and aerodynamic disturbances.

Findings

This review will act as a basis for the future work on modeling and control of VTOL tilt rotor UAV by the researchers. The development of self-guided and fully autonomous UAVs would result in reducing the risk to human life. Civil applications include inspection of rescue teams, terrain, coasts, border patrol buildings, police and pipelines. The simulation results show that the controller achieves robust stability, good adaptability and robust performance.

Originality/value

The review articles on quadrotors/quadcopters, hybrid UAVs can be found in many literature, but there are comparatively a lesser amount of review articles on the detailed description of VTOL Tilt rotor UAV. In this paper modeling, platform design and control algorithms for the tilt rotor are presented. A robust H-infinity loop shaping controller in the presence of disturbances is designed for VTOL UAV.

Details

International Journal of Intelligent Unmanned Systems, vol. 8 no. 3
Type: Research Article
ISSN: 2049-6427

Keywords

Access Restricted. View access options
Article
Publication date: 26 July 2024

Bolanle Oyindamola Adebayo and Hannah M. Sunderman

To maximize the benefits of intercultural mentoring relationships, which are increasing in today’s diverse higher education environment, the current article conceptualizes the…

78

Abstract

Purpose

To maximize the benefits of intercultural mentoring relationships, which are increasing in today’s diverse higher education environment, the current article conceptualizes the connection between intercultural mentoring and cultural competence among mentors and mentees as a learning process.

Design/methodology/approach

The conceptual paper discusses the nuanced aspects of intercultural mentoring. Ultimately, the current article presents a framework for a bidirectional relationship between intercultural mentoring and cultural competence through experiential learning theory and intergroup contact theory, resulting in implications for practitioners and actionable research directions.

Findings

The article highlights the interplay and interdependence of cultural competence and intercultural mentoring through experiential learning and intergroup contact theory. Cultural competence influences the quality of intercultural mentoring relationships. Conversely, intercultural mentoring relationships can develop cultural competence in mentors and mentees through experiential learning, producing positive intergroup contact behaviors. Findings suggest the need for active learning and unlearning among mentors and mentees in intercultural mentoring relationships to maximize developmental outcomes (e.g. cultural competence).

Originality/value

The proposed framework emphasizes that (1) the possession of cultural competence is a critical success factor for intercultural mentoring relationships, (2) the development of cultural competence is an outcome of successful intercultural mentoring relationships, and (3) intercultural mentoring relationships should be regarded as experiential learning platforms that can produce positive intercultural traits such as cultural competence.

Details

International Journal of Mentoring and Coaching in Education, vol. 14 no. 1
Type: Research Article
ISSN: 2046-6854

Keywords

Access Restricted. View access options
Article
Publication date: 8 December 2022

Abdallah Abdul-Mumuni, Barbara Deladem Mensah and Richard Amankwa Fosu

While there are enormous studies on the determinants of environmental degradation, empirical studies on the effect of renewable energy consumption and economic growth on the…

223

Abstract

Purpose

While there are enormous studies on the determinants of environmental degradation, empirical studies on the effect of renewable energy consumption and economic growth on the environment remain limited. The purpose of this paper is to examine the asymmetric effect of renewable energy consumption and economic growth on environmental degradation in 31 selected sub-Saharan African countries spanning from 1990 to 2018.

Design/methodology/approach

To examine possible asymmetric effects of the exogenous variables on environmental degradation, we used the panel nonlinear autoregressive distributed lag approach and secondary data was sourced from the World Bank (2021).

Findings

The cointegration test results suggest that there is a long-run cointegration among the variables whereas our main findings indicate that environmental degradation responds asymmetrically to changes in renewable energy consumption and economic growth. The results further reveal that both positive and negative shocks in renewable energy consumption reduce environmental degradation. On the other hand, positive and negative shocks in economic growth increase environmental degradation in the long run.

Research limitations/implications

The implications of this study include the need for policymakers in sub-Saharan Africa to encourage the utilization of renewable energy as it reduces environmental degradation. Also, governments in the subregion should gradually replace the usage of fossil fuels by adapting renewable energy sources so as to achieve higher economic growth.

Originality/value

The positive and negative shocks of renewable energy consumption and economic growth on environmental degradation are examined to ascertain their asymmetric relationships.

Details

International Journal of Energy Sector Management, vol. 17 no. 5
Type: Research Article
ISSN: 1750-6220

Keywords

Available. Open Access. Open Access
Article
Publication date: 10 February 2025

Nathaniel Ayinde Olatunde, Imoleayo Abraham Awodele, Bosede Olajumoke Adebayo and Sola Samuel Makanjuola

The study examined the factors inhibiting the engagement of Quantity Surveyors (QS) on private residential building projects in Ado-Ekiti, Nigeria with a view to enhance the…

33

Abstract

Purpose

The study examined the factors inhibiting the engagement of Quantity Surveyors (QS) on private residential building projects in Ado-Ekiti, Nigeria with a view to enhance the performance of such projects.

Design/methodology/approach

The study used a qualitative research approach with the use of interview protocol for data collection. A Convenient sampling method was used to select 20 on-going residential building construction projects for the study in the Government Reserved Area, Ado Ekiti, Ekiti State, Nigeria. The client and the architect of the selected projects were the population of research for interview. For data analysis, 28 successful interviews were used, while frequency, percentile and content analysis were the method of data analysis used.

Findings

The result indicated that the most important factor inhibiting the engagement of QSs on private residential building projects is lack of awareness of the benefit inherent in engagement of QS on residential projects. Other important factors are; the perception that engagement of QS will increase the construction cost, absence of legislation that mandate engagement of QS, usurpation of Quantity Surveyor’s roles by other professionals and the perception that engagement of QS is essential only in big projects.

Practical implications

It was recommended that every state chapter of the Nigerian Institute of Quantity Surveyors (NIQS) should start a series of awareness campaign program within their State to enlighten the populace on the services that a professional QS can offer them with emphasis on the benefits of engaging QS on the small scale projects such as residential building projects. More recommendation has it that as a matter of policy and requirement for building approval criteria, deliverables from QS should be made compulsory. This measure will help every potential residential building client to see QS as an important professional that must be engaged before their project can be successfully delivered.

Originality/value

The study attempted to investigate the factors inhibiting the engagement of QS on private residential building construction projects. This was motivated by the perceived prevalent of non-engagement of QS in the study area with the attendant poor project performance.

Details

Journal of Financial Management of Property and Construction, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1366-4387

Keywords

Available. Open Access. Open Access
Article
Publication date: 23 July 2024

Adeyemi Adebayo and Barry Ackers

Within the context of public sector accountability, the purpose of this paper is to examine South African state-owned enterprises (SOEs) auditing practices and how they have…

918

Abstract

Purpose

Within the context of public sector accountability, the purpose of this paper is to examine South African state-owned enterprises (SOEs) auditing practices and how they have contributed to mitigating prevalent corporate governance issues in South African SOEs.

Design/methodology/approach

This paper utilised a thematic content analysis of archival documents relating to South African SOEs. Firstly, to assess the extent to which the auditing dimension of the corporate governance codes, applicable to South African SOEs, conforms with best practices. Secondly, to determine the extent to which the audit practices of all the 21 South African SOEs listed in Schedule 2 of the Public Finance Management Act, have implemented the identified best audit practices.

Findings

The findings suggest that South African SOEs appear to have adopted and implemented best audit practices to enhance the quality of their accountability in relation to their corporate governance practices, as contained in their applicable corporate governance frameworks. However, despite the high levels of conformance, the observation that most South African SOEs continue to fail and require government bailouts, appears to suggest that auditing has no bearing on poor SOE performance, and that other corporate governance factors may be at play.

Practical implications

The discussion and findings in this paper suggest that the auditing practices of South African SOEs are adequate. However, that SOEs in South Africa continue to be loss-making may imply that this has contributed little to mitigating their corporate governance problems. Thus, policymakers and standard setters, including the Institute of Directors South Africa and relevant oversight bodies should pay attention to better developing means by which to curtail fruitless and wasteful expenditures by South African SOEs through improved corporate governance practices.

Social implications

Most SOEs’ mission statements encourage SOEs to be socially responsible and utilise taxpayers’ monies efficiently and effectively without engaging in fruitless and wasteful expenditure. This study is conceived in this light.

Originality/value

To the best of the author’s knowledge, while acknowledging previous studies, this paper is the first to explore this topic in the context of SOEs and in the context of Africa.

Details

Meditari Accountancy Research, vol. 32 no. 7
Type: Research Article
ISSN: 2049-372X

Keywords

Access Restricted. View access options
Article
Publication date: 13 September 2022

Bright Akwasi Gyamfi, Paul Adjei Kwakwa and Tomiwa Sunday Adebayo

The International Energy Agency states that the global energy intensity must reduce by 2.9% yearly before attaining Sustainable Development Goal 7.3 by 2030. However, the European…

486

Abstract

Purpose

The International Energy Agency states that the global energy intensity must reduce by 2.9% yearly before attaining Sustainable Development Goal 7.3 by 2030. However, the European Union (EU) seeking to attain a climate-neutral EU by 2050 shall require a substantial rate of reducing energy intensity. Consequently, this study aims to investigate how (clean) renewable energy, income, trade openness, technological innovation and nonrenewable energy consumption impact energy intensity for the EU countries.

Design/methodology/approach

The quantile regression, augmented mean group and causality techniques were used for analyses. Panel data for 26 EU nations over the 1990 and 2019 period was used.

Findings

The empirical evidence indicates that the variables have long-run equilibrium relationships. However, the analysis revealed that clean energy and income reduce energy intensity whiles trade, technological innovation and nonrenewable energy consumption increase energy intensity. An interactive term analysis shows that renewable energy and trade interact to reduce further, the negative effect of income on energy intensity. Causality results revealed a feedback connection between energy intensity and clean energy, income, trade liberalization as well as the interaction between income and trade liberalization. A one-way causality was obtained between energy intensity and technological innovation, nonrenewable energy consumption and the interaction between clean energy and income.

Practical implications

The results imply that EU countries stand to gain if more resources are committed to encouraging the production and consumption of cleaner/renewable energy. Advancement in policies that support renewable energy and facilitate green growth will help reduce energy intensity for the region. Trade policies that promote lower energy consumption should be strengthened.

Originality/value

The effect of renewable energy on energy intensity is assessed. The moderating impact of renewable energy and trade openness on the income–energy intensity relationship for the EU countries is examined. Moreover, this study uses the quantile estimation technique to assess the nonlinear effect of the explanatory variables on energy intensity.

Details

International Journal of Energy Sector Management, vol. 17 no. 4
Type: Research Article
ISSN: 1750-6220

Keywords

Access Restricted. View access options
Article
Publication date: 8 January 2025

Emna Mnif, Nahed Zghidi and Anis Jarboui

Cryptocurrencies have transformed the financial landscape and raised environmental concerns, particularly distinguishing between energy-intensive (dirty) cryptocurrencies and…

39

Abstract

Purpose

Cryptocurrencies have transformed the financial landscape and raised environmental concerns, particularly distinguishing between energy-intensive (dirty) cryptocurrencies and environmentally friendly (green) cryptocurrencies. This study investigates the role of energy-intensive and ecologically friendly cryptocurrencies in sustainable investments, exploring their potential as hedging tools amid market and geopolitical stresses.

Design/methodology/approach

Employing a time-varying parameter vector auto-regression (TVP-VAR) connectedness approach, the research analyzes the interactions and spillover effects among clean and dirty cryptocurrencies, green bonds, and traditional financial assets. It also explores portfolio diversification strategies like minimum variance, correlation and connectedness portfolios, evaluating their risk minimization efficacy while incorporating green financial instruments. Empirical data on daily closing prices and financial indices are used to assess financial interconnectedness and evaluate portfolio diversification strategies.

Findings

Green bonds consistently provide strong hedging capabilities, while clean cryptocurrencies exhibit a more nuanced role influenced by market maturity and regulations. The results underscore the significance of promoting green finance to bolster investments in sustainable projects and enhance risk management strategies for investors. This research enriches the green finance literature by detailing the financial interconnectedness within the market and providing strategic insights for embedding sustainability in investment portfolios against a backdrop of global economic and geopolitical uncertainties.

Research limitations/implications

The research highlights the importance of green finance in promoting sustainability and reducing environmental impact. It advocates for regulatory frameworks that support sustainable financial instruments, encouraging the development of financial products aligned with environmental goals and fostering a more sustainable economy.

Practical implications

These research findings provide actionable guidance for investors and policymakers to develop diversified investment strategies incorporating green bonds and clean cryptocurrencies capable of balancing risks and returns. The study also urges policymakers to establish clear guidelines and incentives for green investments, improving transparency and effectiveness in green finance markets.

Originality/value

This study uses an innovative TVP-VAR connectedness approach to examine the interactions and spillover effects among clean and dirty cryptocurrencies, green bonds and traditional financial assets. It provides new insights into the roles of green bonds and clean cryptocurrencies as hedging tools in volatile markets, enhancing the understanding of financial interconnectedness and sustainable investment strategies.

Details

Management of Environmental Quality: An International Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1477-7835

Keywords

1 – 10 of 672
Per page
102050