Search results

Major land use changes can have a significant impact on the environment, e.g. increased leaching and run‐off losses of nutrients and water contamination. Nitrate (NO₃^–) can be easily leached and, when present at high concentrations in drinking water, can be a health hazard. This paper seeks to report an easy‐to‐use computer model designed to provide predictions of possible impacts on groundwater NO₃^– concentration on a regional scale.

The model takes into account NO₃^–‐N concentrations from various land use activities, land surface recharge rates (as affected by soil water retention capacity, land management, irrigation and rainfall), and mixing of surface recharge and river recharge. Spatial information on land use and groundwater recharge sources are lumped into groundwater management zones (100‐500 km²), and vertical concentration profiles of NO₃^– in groundwater are estimated from a one‐dimensional dispersion model. The model is applied to the 2,300 km² Central Canterbury Plains of New Zealand.

A scenario analysis for the Bankside groundwater management zone showed that the NO₃^–‐N concentration at the groundwater surface could increase from 7.8 mg N L^‐1 to 11.3 mg N L^‐1 if all the land used for sheep farming is replaced by dairy farming (increasing dairy land from 21 per cent to 64 per cent of the total land area). However, the impact of such land use changes on the NO₃^–‐N concentration 50 m below the groundwater surface was relatively small, resulting in an increase of NO₃^–‐N concentration from 0.4 to 0.5 mg N L^‐1. This is because of the significant mixing of surface recharge with river recharge at this depth.

The model can serve as a useful tool for first‐order estimation of possible trends of NO₃^–‐N concentration profiles in aquifers as a result of land use changes.

The purpose of this paper is to examine the effects of bank ownership structure and ownership concentration on credit risk.

Using panel data on a sample of 88 Chinese commercial banks, with 826 observations over a period of 2003–2018, this study has applied system generalised method of moments regression to examine the impact of bank ownership structure and ownership concentration on credit risk. This study has used two measures of credit risk, which are non-performing loan ratio (NPLR) and loan loss provision ratio (LLPR).

The results show that ownership type (both government and private ownership) exerts a positive and significant impact on credit risk. Measuring ownership concentration using Herfindahl–Hirchmann Index, the results indicate that concentration of ownership in the hands of government has a negative and significant effect on credit risk, whereas private ownership concentration positively impacts credit risk. Overall, the findings suggest that concentration of ownership in government hands reduces risk; however, private ownership concentration exacerbates credit risks. The results are invariant to both measures of credit risk, before and after the financial crisis.

The findings provide useful insight to guide policy decisions in Chinese banks’ lending policies and bank ownership.

Using two ex post measures of credit risk, NPLR and LLPR, and one ownership concentration measure, HHI, this study deepens our understanding on the effectiveness of Chinese banks’ corporate governance reforms on managing credit risks.

The aim of the present work was to study the synergistic effect of HEDP and zinc on inhibition of the corrosion of carbon steel in neutral oxygen‐containing chloride solutions, and to investigate the effect of zinc‐HEDP molar ratio on the effectiveness of the zinc‐HEDP inhibitive mixtures.

The inhibition of the corrosion of carbon steel by zinc‐HEDP mixtures in neutral oxygen‐containing solutions was investigated in the presence of 0.003 M (106 ppm) chloride.

It was shown that the inhibition by these mixtures depended not only on the zinc/HEDP molar ratio but also on the concentration of both zinc and HEDP. HEDP concentration appeared to be crucial where good inhibition was not achieved at low concentrations and aggressive nature is observed at high HEDP levels. The effectiveness of the zinc‐HEDP mixtures enhanced inhibition by increasing the zinc content of the mixture, but the mechanism was only effective to a certain level, above which the inhibition effect declined. The predominant corrosion control mechanism of the zinc‐HEDP mixture was on the anodic (metal dissolution) reaction, but it also affected the rate and mechanism of the oxygen reduction reaction.

Demonstrates how the effectiveness of the zinc‐HEDP mixtures can enhance inhibition by increasing the zinc content of the mixture.

While concentration measures are a good indicator of market structure, the link with competitiveness is more complex than often assumed. In particular, the modern theory of industrial organisation makes no clear statement regarding the impact of concentration on competition ‐ the focus of this paper is concentration and no inferences are made about competitive aspects of the market. The extent and nature of concentration within the UK listed company audit market as at April, 2002 and, pro forma, after the collapse of Andersen is documented and analysed in detail (by firm, market segment and industry sector). The largest four firms held 90 per cent of the market (based on audit fees) in 2002, rising to 96 per cent with the demise of Andersen. A single firm, Pricewaterhouse‐Coopers, held 70 per cent or more of the share of six out of 38 industry sectors, with a share of 50 per cent up to 70 per cent in a further seven sectors. The provision of non‐audit services (NAS) by incumbent auditors is also considered. As at April 2002, the average ratio of non‐audit fees (paid to auditor) to audit fees was 208 per cent, and exceeded 300 per cent in seven sectors. It is likely, however, that disposals by firms of their management consultancy and outsource firms, combined with the impact of the Smith Report on audit committees will serve to reduce these ratios. Another finding is that audit firms with expertise in a particular sector appeared to earn significantly higher nonaudit fees from their audit clients in that sector. The paper thus provides a solid empirical basis for debate. The subsequent discussion considers the implications for companies and audit firms of the high level of concentration in the current regulatory climate, where no direct regulatory intervention is planned.

This paper aims to clarify the relationship between institutional framework, concentration of ownership in family firms and results.

Data comprises two samples of family firms from eight Latin American countries and Spain in the year 2010. The first sample contains the largest 20 corporations from each country. The second comprises the 20 largest listed family corporations in each country. To test the hypothesis, the study uses ordinary least squares.

First, firms located in countries with a higher than average quality of the institutional and regulatory frameworks are less concentrated in ownership than firms located in countries with lower than average quality and development of institutional and regulatory framework. Second, the influence of the concentration of the ownership in the performance is more important in countries with higher developed institutional and regulatory frameworks. Finally, first-generation large family firms obtain higher results than large family firms in second generation or beyond.

The study is limited to one year and there are few family firms in Latin American countries. The study only considers some features of ownership, and there is no information about board of directors ' composition.

Institutional framework determines concentration of ownership in family firms and the influence of concentration of ownership in performance.

The study provides new evidence in areas of corporate governance and family firms, analysing a sample of Latin American and Spanish firms, representatives of the civil legal system and a weaker institutional framework. The study uses the corruption perception index like a control variable.

The purpose of this study is to monitor suspended particulate matter (SPM), PM2.5 and source apportionment study for the identification of possible sources during the year 2018–2019 at Raipur, India.

Source apportionment study was performed using a multivariate receptor model, positive matrix factorization (PMFv5.0) with a view to identify the various possible sources of particulate matter in the area. Back-trajectory analysis was also performed using NOAA-HYSPLIT model to understand the origin and trans-boundary movement of air mass over the sampling location.

Daily average SPM and PM2.5 aerosols mass concentration was found to be 377.19 ± 157.24 µg/m³ and 126.39 ± 37.77 µg/m³ respectively. SPM and PM2.5 mass concentrations showed distinct seasonal cycle; SPM – (Winter ; 377.19 ±157.25 µg/m?) > (Summer; 283.57 ±93.18 µg/m?) > (Monsoon; 33.20 ±16.32 µg/m?) and PM2.5 – (Winter; 126.39±37.77 µg/m³) > (Summer; 75.92±12.28 µg/m³). Source apportionment model (PMF) have been applied and identified five major sources contributing the pollution; steel production and industry (68%), vehicular and re-suspended road dust (10.1%), heavy oil combustion (10.1%), tire wear and brake wear/abrasion (8%) and crustal/Earth crust (3.7%). Industrial activities have been identified as major contributing factor for air quality degradation in the region.

Chemical characterization of aerosols and identification of possible sources will be helpful in abatement of pollution and framing mitigating strategies. It will also help in standardization of global climate model.

The findings provide valuable results to be considered for controlling air pollution in the region.

The purpose of this paper is to examine the presence of geogenic contaminants in groundwater from shallow aquifers of the crystalline basement complex rocks of Ibadan south-western, Nigeria.

A total of 30 drinking water samples, (six samples each from the five major lithologic formations of the study area) were collected from hand dug wells during the rainy season. Atomic absorption spectrophotometry was used to determine concentrations of arsenic, iron and fluoride in drinking water samples and also concentrations of other chemical parameters that could affect the concentrations of the geogenic contaminants including pH, Ca, Mg, Na and SO₄2−. Descriptive statistics, multiple correlation and analysis of variance were used to examine the relationship between the geogenic contaminants and concentration of other chemical parameters while inverse distance weighting was used to produce risk maps.

The results showed Arsenic concentration exceeding the WHO recommended concentration for drinking water in all the samples within the area. Samples from 16.6 per cent of the wells exceeded the recommended limit for fluoride while iron was present in most of the samples within acceptable limits. The study also revealed no significant difference in concentration of contaminants between the geologic formations.

Geogenic contamination has been scarcely studied in Nigeria. This research, therefore, is a paradigm shift in the study of groundwater contamination which had been mainly focused on anthropogenic contaminants. The outcome of this research will engender policy makers and researchers to pay more attention to geogenic contamination than anthropogenic contaminants in Nigeria.

The purpose of this study is to investigate the performance of the fabricated liquid–liquid hydrocyclone (LLHC) with dimensions similar to those of one of the Malaysian oilfields with the presence of an anionic surfactant, S672. The effect of salinity and initial oil concentration were also investigated following the actual range concentration.

The current control system’s pressure drop ratio (PDR) does not necessarily lead to an efficient LLHC. Therefore, rather than using the PDR, the efficiency of the LLHC was analyzed by comparing the concentration of oil in the effluents with the concentration of oil at the feed of the LLHC. An LLHC test rig was developed at Centre of Enhanced Oil Recovery, Universiti Teknologi PETRONAS. Emulsions were prepared by mixing the brines, S672 and oil by using Ultra Turrax ultrasonic mixer. The emulsion was pumped into the LLHC at different feed flowrate and split ratio. The brines concentration, initial oil concentration and S672 concentration were also varied in this study. Samples were taken at the underflow of the LLHC and the oil in water concentration analysis was done for the samples using TD-500D equipment.

It was found that the efficiency of oil removal decreased with an increase in S672 concentration but increased with the increase in salinity and initial oil concentration.

The optimum feed flowrate for the LLHC of 45 mm diameter and length of 1,125 mm with the presence of S672 surfactant was found to be 40 L/min with a split ratio of 14%. This study can be used as a guidance for future optimization of the LLHC in the presence of the surfactant.

This study aims to investigate thermo-bioconvection of oxytactic microorganisms occurring in a nanofluid-saturated porous lid-driven cavity in the presence of the magnetic field. The heating is provided through a bell-shaped curved bottom wall heated isothermally. The effects of the peak height of the curved bottom wall, bioconvection Rayleigh number (Rb), Darcy number (Da), Hartmann number (Ha), Peclet number (Pe), Lewis number (Le) and Grashof number (Gr) on the flow structure, temperature and the iso-concentrations of oxygen and microorganisms are examined and explained systematically. The local and global, characteristics of heat transfer and oxygen concentration, are estimated through the Nusselt number (Nu) and Sherwood number (Sh), respectively.

The governing equations of continuity, momentum, energy and additionally consisting of species transport equations for oxygen concentration and population density of microorganisms, are discretized by the finite volume method. The evolved linearized algebraic equations are solved iteratively through the alternate direction implicit scheme and the tri-diagonal matrix algorithm. The computation domain has meshed in non-uniform staggered grids. The entire computations are carried out through an in-house developed code written in FORTRAN following the SIMPLE algorithm. The third-order upwind and second-order central difference schemes are used for handling the advection and diffusion terms, respectively. The convergence criterion for the iterative process of achieving the final solution is set as 10–8 and 10–10, respectively, for the maximum residuals and the mass defect.

The results show that the flow and temperature distribution along with the iso-concentrations of oxygen and microorganisms are markedly affected by the curvature of the bottom wall. A secondary circulation is developed in the cavity that changes the flow physics significantly. The Nu increases with the peak height of the curved bottom wall and Da; however, it decreases with Ha and Rb. The Sh increases with Da but decreases with Ha and the peak height of the curved wall.

A similar study of bioconvection could be extended further considering thermal radiation, chemical attraction, gravity, light, etc.

The outcomes of this investigation could be used in diverse fields of multi-physical applications such as in food industries, chemical processing equipment, fuel cell technology and enhanced oil recovery.

The insights of bioconvection of oxytactic microorganisms using a curved bottom surface along with other physical issues such as nanofluid, porous substance and magnetic field are addressed systematically and thoroughly.

The purpose of this paper is to examine the effect of bank consolidation and foreign ownership on bank risk taking in the Egyptian banking sector.

Following prior studies (e.g. Yeyati and Micco, 2007; Barry et al., 2011), this study uses pooled Ordinary Least Squares regression models under two main analyses to test the relation between concentration and foreign ownership on one hand and bank risk-taking behavior on the other hand, where observations are pooled across banks and years for the 2000-2011 period. The reform plan was launched in 2004 and resulted in various restructuring activities in the banking system. Thus, to control for the effect of implementing the financial sector reform plan on bank insolvency and credit risk, this study includes a reform dummy variable (RFM) for the post-reform period in models testing the association between consolidation, foreign ownership and bank risk. Therefore, this categorical variable identifies whether bank risk is related to the reform activities that have been observed during the post-restructuring period, 2005-2011. Moreover, to accommodate the possibility that effects of bank concentration and foreign ownership on bank risk differ due to the implementation of the reform plan, the author create two interaction terms: one uses the product of the reform dummy variable and concentration measures, while the other uses the product of the reform dummy and foreign ownership variables to capture interactions. These interaction terms and the dummy variable provide ample room to capture the effect of bank concentration and foreign ownership on bank risks during the post-reform period.

This study provides empirical evidence that bank concentration is associated with low insolvency risk and credit risk as measured by loan loss provisions (LLP) in the post-reform period. These results are consistent with the “concentration-stability” view, suggesting that concentration of the banking sector will enhance stability. Moreover, evidence shows that while a higher presence of foreign banks reduces bank credit risk in the post-reform period, it appears to increase insolvency risk. These results are robust to using alternative measures. These findings imply that regulators in emerging countries should support foreign investments in banks to transfer better managerial skills and systems. However, government-owned banks are found to be more prone to insolvency and credit risks; thus, their ownership should not be encouraged. Finally, policy makers should reinforce bank consolidation, be prudent in determining the capital adequacy ratio (CAR) and monitor intensively less profitable, well-capitalized and small-sized banks.

Consolidation of the banking sector decreases insolvency risk and credit risk, as measured by LLP in the post-reform period. This study proposes that bank supervisors implement prudent polices in determining the bank CAR, and monitor intensively less profitable, well-capitalized and smaller banks, as they have incentives to increase risk. In addition, regulators should encourage foreign investment in the banking sector and facilitate their operations in Egypt.

Bank supervisors should intensely monitor banks with high-CARs that exceed mandatory requirements because they may be more likely to engage in more risk-taking activities.

It provides empirical evidence from a country-specific, emerging market perspective, in which restructuring events affect the national economy. Egypt, similar to other emerging countries in Africa, pursues an institutionally based (bank-based) system of corporate governance, where banks are the primary sources of finance for firms. Therefore, restructuring banks and other financial institutions and supervising their operations ensure the soundness and stability of these institutions, which represent the nerve of emerging economies. Because emerging countries tend to share common characteristics and economic conditions, and the reform of their financial systems is significant for economic development, the Egyptian banking reform and restructuring program should be of interest to other emerging countries to capitalize on this experiment. While international studies on these relationships are mostly cross-country or focus on US banks, firm-specific studies are scant. Furthermore, the findings of this study should be of interest to Egyptian regulators, bank supervisors and policy makers studying the implications of bank reforms.