Search results

The purpose of this study is to determine the contamination level in natural water resources because the tremendous development in the agriculture sector has increased the amount of contamination in natural water sources. Hence, the water is polluted and unsafe to drink.

Three types of sensor arrays were suggested: parallel, star and delta. The simulation of all types of sensor array was carried out to calculate the sensors’ impedance value, capacitance and inductance during their operation to determine the best sensor array. The contamination state was simulated by altering the electrical properties values of the environmental domain of the model to represent water contamination.

The simulation results show that all types of sensor array are sensitive to conductivity, σ, and permittivity, ɛ (i.e. contaminated water). Furthermore, a set of experiments was conducted to determine the relationship between the sensor’s impedance and the water’s nitrate and sulphate contamination. The performance of the system was observed where the sensors were tested, with the addition of distilled water with different concentrations of potassium nitrate and potassium sulphate. The sensitivity of the developed sensors was evaluated and the best sensor was selected.

Based on the outcomes of the experiments, the star sensor array has the highest sensitivity and can be used to measure nitrate and sulphate contaminations in water.

The star sensor array presented in this paper has the potential to be used as a useful low-cost tool for water source monitoring.

This paper aims to present a review of the design and development of the turbidimeter for measuring the turbidity level in water. Monitoring the turbidity level of water is important because it is related to public health.

A precise and reliable turbidimeter can provide vital data that reveals the water condition level. Several turbidimeter units are discussed briefly. Three types of turbidimeter design – single beam, ratio and modulated four beams – are elaborated with some illustrations of the design concept. Various improvements and innovations for upgrading turbidimeter design are also discussed.

This paper elaborated on a new method of estimating the water turbidity level in water samples using an optical tomography system based on the independent component analysis method. The results showed that a tomography-based turbidimeter can measure slight changes in the level of turbidity when the volume of contaminants is changed slightly. The turbidimeter can also provide a profile of the distribution of the turbidity in the water sample.

A turbidimeter based on the optical tomography concept can be a valuable tool in determining the level of pollution in rivers, sea, etc.

The study aims to summarize the 20 years of literature published in takaful between 2000 and 2019 and propose some key areas as the directions for future research.

The present study utilizes the systematic method of reviewing the literature. The SCOPUS database has been accessed, and 96 articles have been accounted for the analysis. The articles are grouped in their exclusive themes, such as consumer behavior, financial and nonfinancial performance, takaful models, human resources and governance.

Takaful research has widely covered marketing, finance, human resource, governance and stresses on its legal issues. Both qualitative and quantitative methodologies have been employed. The research gaps have been classified based on the respective areas. Large share of current body of takaful literature consists of the studies related to the application of behavioural theories to examine the behavioural intention to take up takaful services.

The study enriches the literature of takaful by reviewing articles according to their respective themes, thereby contributing to the significant findings missing from existing literature surveys.