Search results

1 – 2 of 2
Article
Publication date: 4 January 2021

Ben Mansour Dia

The author examine the sequestration of CO2 in abandoned geological formations where leakages are permitted up to only a certain threshold to meet the international CO2

Abstract

Purpose

The author examine the sequestration of CO2 in abandoned geological formations where leakages are permitted up to only a certain threshold to meet the international CO2 emissions standards. Technically, the author address a Bayesian experimental design problem to optimally mitigate uncertainties and to perform risk assessment on a CO2 sequestration model, where the parameters to be inferred are random subsurface properties while the quantity of interest is desired to be kept within safety margins.

Design/methodology/approach

The author start with a probabilistic formulation of learning the leak-age rate, and the author later relax it to a Bayesian experimental design of learning the formations geo-physical properties. The injection rate is the design parameter, and the learned properties are used to estimate the leakage rate by means of a nonlinear operator. The forward model governs a two-phase two-component flow in a porous medium with no solubility of CO2 in water. The Laplace approximation is combined with Monte Carlo sampling to estimate the expectation of the Kullback–Leibler divergence that stands for the objective function.

Findings

Different scenarios, of confining CO2 while measuring the risk of harmful leakages, are analyzed numerically. The efficiency of the inversion of the CO2 leakage rate improves with the injection rate as great improvements, in terms of the accuracy of the estimation of the formation properties, are noticed. However, this study shows that those results do not imply in any way that the learned value of the CO2 leakage should exhibit the same behavior. Also this study enhances the implementation of CO2 sequestrations by extending the duration given by the reservoir capacity, controlling the injection while the emissions remain in agreement with the international standards.

Originality/value

Uncertainty quantification of the reservoir properties is addressed. Nonlinear goal-oriented inverse problem, for the estimation of the leakage rate, is known to be very challenging. This study presents a relaxation of the probabilistic design of learning the leakage rate to the Bayesian experimental design of learning the reservoir geophysical properties.

Details

Engineering Computations, vol. 38 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 3 August 2021

Ahmad Yuosef Alodat, Zalailah Salleh, Hafiza Aishah Hashim and Farizah Sulong

This study aims to assess the effect of director board and audit committee attributes and ownership structure on firm performance. In general, resource dependency and…

1056

Abstract

Purpose

This study aims to assess the effect of director board and audit committee attributes and ownership structure on firm performance. In general, resource dependency and agency theories have underlined the superior performance of firms equipped with stronger Corporate Governance (CG) versus those of deficient governance. Concurrently, the study delineated the provisions of ownership structure provision, specifically foreign ownership and institutional ownerships, thus describing the component denoting the structural significance in explicating firm performance.

Design/methodology/approach

The current study implemented an empirical approach involving the construction of extensive CG measures thus, subjected to 81 non-financial firms listed on the Amman Stock Exchange spanning the period of 2014–2018.

Findings

The current study identified the positive and significant relationship between the board of directors and audit committee characteristics with the firm performance measures tested, namely, return on equity (ROE) and Tobin’s Q. In terms of ownership structure, both foreign and institutional ownerships yielded a significant and positive relationship with ROE. Meanwhile, Tobin’s Q led to an insignificant and negative relationship between both ownership types and firm performance measures.

Practical implications

The analytical outcomes substantiate the possibility of enhanced performance shown by growing global firms because of the implementation of CG mechanisms, specifically because of the practices resulting in minimised agency costs.

Originality/value

The current study offers novel evidence detailing the impact of CG effectiveness towards performance and its implementation in emerging markets following the minimal amount of scholarly efforts on the topic. It is a timely contribution towards the current understanding of the relationship linking governance and performance for the purpose of ensuring the adoption and imposition of a strong corporate governance code by the government.

Details

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

Keywords

1 – 2 of 2