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Increase in population and urbanisation alongside demands from agricultural sector towards meeting fresh produce needs of the growing population has put severe pressure on the available natural water sources all over the world. Thus, water is undoubtedly the most contemporary crucial resources in the world. Aquatic weed plants are generally seen as a global threat to humans and aquatic ecosystem as they cannot be wholly eliminated easily. Still, various researchers and investigations have shown that they are instrumental in the field of wastewater phytoremediation, either in constructed wetlands, open ponds or hydroponic systems in an eco-friendly and economical manner with little or no sludge waste. In view of the increasing search for an alternative source of a sustainable method for wastewater reclamation, this study presents a concise review of relevant literatures on the roles of constructed wetlands and hydroponic systems in phytoremediation of wastewater. Also in the course of this study, the authors discovered that constructed wetlands and hydroponic systems have proven to be productive in remediating an array of water quality problems, with merits over the regular wetlands and conventional methods. Nonetheless, these methods are endowed with drawbacks such as inconsistency in the absorption of contaminants, large area space requirement, over dependency on environmental conditions and energy requirement. However, we suggest the use of engineered hybrid to improve its efficiency in wastewater treatment and bioenergy generation. In the case of hydroponic systems, an alternative sustainable solar energy or devices can be used to power the systems to obtain effective results at a low cost. Additionally, further studies can be employed in the use of phytoremediation technique for synchronous remediation of wastewater and production of biomass on industrial scale.

Quality determines the shelf-life and selling prices of fresh mango, and therefore quality observation and control of fresh mango are of utmost significance in the processing and management of its supply chain. Mango fruit (mangifera indica) quality methods are mostly destructive in nature. Different mechanical, electromagnetic and non-destructive methods are increasingly important nowadays because of the ease of operation, speed, and reliability of the process. This project aims to develop a non-destructive assessment of mango quality using handheld micro NIR (near-infrared) spectroscopic device. NIR spectra data and Brix levels, which indicate the sugar content of the plant, i.e. indicating the sweetness of the mango, were collected from three different types of Mango (Chokanan, Rainbow, and Kai Te), resulting 80 samples (i.e. 60 samples for training and 20 samples for testing) in this project. NIR spectra can be converted mathematically to obtain quantitative information of chemical and physical nature by multivariate calibration. The spectra data is pre-processed using Gaussian smoothing and extended multiplicative signal correction (EMSC) for the elimination of uncontrollable path length or scattering effects. These samples were then used to develop a predictive model using both Support Vector Machine (SVM) regression and Partial Least Squares regression (PLS) methods. The coefficient of determination (R2) obtained from SVM for training/calibration and testing dataset are 0.96 and 0.95 respectively. Meanwhile, the coefficient of determination (R2) obtained from PLS for calibration/training and testing dataset are 0.89 and 0.86 respectively. The results obtained from this project indicate that the handheld NIR has potential use for non-destructive assessment of mango fruits quality.

Cuckoo Search (CS) and Differential Evolution (DE) algorithms are considerably robust meta-heuristic algorithms to solve constrained optimization problems. In this study, the performance of CS and DE are compared in solving the constrained optimization problem from selected benchmark functions. Selection of the benchmark functions are based on active or inactive constraints and dimensionality of variables (i.e. number of solution variable). In addition, a specific constraint handling and stopping criterion technique are adopted in the optimization algorithm. The results show, CS approach outperforms DE in term of repeatability and the quality of the optimum solutions.

In this paper, a two-degree of freedom (2DOF) controller is designed for a ball and beam system. The controller is developed based on the algebraic method. The ball and beam system is one of the most popular laboratory experiments for control education. The controller is designed such that the ball can track a square wave with a certain design specification. The advantages of 2DOF controller are the feedback controller takes care of the uncertainty and the feedforward filter ensures the tracking of the reference command. Though the control method is not new, the application of the technique on such unstable system is of interest. Controlling the ball on the beam is a challenging task because of the instability of the system and the fact that the output, i.e. the ball position, increases almost without limit for a fixed input beam angle. The controller needs to regulate the position of the ball by changing the angle of the beam at the pivot point. It is a difficult control task as the ball moves with an acceleration which is proportional to the tilt angle of the beam. Two types of 2DOF controllers are considered; based on dominant pole design and based on integral time absolute error (ITAE) design. The performances of the resulting controllers are compared. Simulations were run over various frequencies. The results indicate the effectiveness of the designed 2DOF controllers in achieving the design specification.