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A unique in-pipe hydropower prototype with a water separation feature, designated as P40 is developed in this research. Fabricated mainly using steel-based materials, it has two power generation (PG) channels with nozzles and turbines. Water flows into the PG channels and is controlled by inlet and outlet valves. From the experiment, it showed that all valves in P40 functioned well as it prevented water from flowing into the PG channels. P40 works effectively as a device that allows most water to flow uninterrupted. With a valve that works well, this system allows maintenance to be done without having to disrupt the flow of water to the consumer. It is also expected to generate more power compared to the previous studies.

An experimental study was conducted to study the effects of flow uniformity on vibration and power generation of a small vertical axis wind turbine (VAWT). Previous studies have confirmed that one of the sources of vibration in the turbine is due to aerodynamic forces, which are due to incident wind. Firstly, understanding vibration is essential before proceeding to the measurements. In this experiment, further understand the vibrations of the turbine in operation, the operating deflection shape (ODS) technique was used. A wind tunnel and flow conditioner were fabricated. Experimental modal analysis (EMA) was conducted, and the dynamic characteristics are gathered. The ODS was conducted for operating the turbine at different speeds, with and without the flow conditioner. Results from EMA and ODS are correlated to explain the behavior of structures. In conclusion, the flow conditioner tested did have a big impact on the response of the structure in terms of vibration up to 30% indifference, but not so much in power generated about 2% indifference.

Magnetorheological elastomers (MREs) are smart viscoelastic materials in which their physical properties can be altered when subjected to a varying magnetic field strength. MREs consist of an elastomeric matrix mixed with magnetic particles, typically carbonyl iron particles (CIPs). The magnetic field-responsive property of MREs have led to their wide exposure in research. The potential development and commercialization of MRE-based devices requires extensive investigation to identify the essential factors that can affect their properties. For this reason, this research aims to investigate the impact of CIPs’ type, concentration and coating on the rheological and mechanical properties of MREs. Isotropic MREs are fabricated with four different CIP compositions differing between hard or soft, and coated or uncoated samples. Each MRE composition have three different concentrations, which is 5%, 10%, and 20% by volume. The dynamic properties of the fabricated samples are tested by compression oscillations on a dynamic mechanical analyzer (DMA). Frequency and strain dependent measurements are performed to obtain the storage and loss modulus under different excitation frequencies and strain amplitudes. The emphasis is on the magnetorheological (MR) effect and the Payne effect which are an intrinsic characteristics of MREs. The effect of the CIPs’ type, coating, and concentration on the MR and Payne effect of MREs are elucidated. Overall, it is observed that, the storage and loss modulus exhibit a strong dependence on both the frequency excitations and the strain amplitudes. Samples with hard and coated CIPs tend to have a higher MR effect than other samples. A decrease in the storage modulus and non-monotonous behavior of the loss modulus with increasing strain amplitude are observed, indicating the Payne effect. The results of this study can aid in the characterization of MREs and the proper selection of CIPs grades based on the application.

Magnetorheological elastomers (MREs) are a class of emerging smart materials in which their mechanical and rheological properties can be immediately and reversibly altered upon the application of a magnetic field. The change in the MRE properties under the magnetic field is widely known as the magnetorheological (MR) effect. Despite their inherent viscoelastic property-change characteristics, there are disadvantages incorporated with MREs, such as slow response time and the suspension of the magnetic particles in the elastomer matrix, which depress their MR effect. This study investigates the feasibility of a hybrid magnetorheological elastomer-fluid (MRE-F) for longitudinal vibration isolation. The hybrid MRE-F is fabricated by encapsulating MR fluid inside the elastomer matrix. The inclusion of the MR fluid can enhance the MR effect of the elastomer by providing a better response to the magnetic field and, hence, can improve the vibration isolation capabilities. For this purpose, an MRE-based coupling is developed, and isolation performance is investigated in terms of the linear transmissibility factor. The performance of the hybrid MRE-F was compared against two different MRE samples. The results show that further enhancement of MR-effect in MREs is possible by including MR fluid inside the elastomer. The hybrid MRE-F exhibited better stiffness change with the current increase and recorded the highest value of 55.911amp;nbsp;N/mm. The transmissivity curves revealed that the MRE-F contributed to a broader shift in the natural frequency with a 7.2amp;nbsp;Hz overall shift at 8.9amp;nbsp;mT. The damping characteristics are higher in MRE-F, recording the highest percentage increase in damping with 33.04%. Overall, the results reveal the promising potential of hybrid MRE-F in developing MRE-based coupling for longitudinal vibration isolation.

Wind turbine technology is well known around the globe as an eco-friendly and effective renewable power source. However, this technology often faces reliability problems due to structural vibration. This study proposes a smart semi-active vibration control system using Magnetorheological (MR) dampers where feedback controllers are optimized with nature-inspired algorithms. Proportional integral derivative (PID) and Proportional integral (PI) controllers are designed to achieve the optimal desired force and current input for MR the damper. PID control parameters are optimized using an Ant colony optimization (ACO) algorithm. The effectiveness of the ACO algorithm is validated by comparing its performance with Ziegler-Nichols (Z-N) and particle swarm optimization (PSO). The placement of the MR damper on the tower is also investigated to ensure structural balance and optimal desired force from the MR damper. The simulation results show that the proposed semi-active PID-ACO control strategy can significantly reduce vibration on the wind turbine tower under different frequencies (i.e., 67%, 73%, 79% and 34.4% at 2 Hz, 3 Hz, 4.6 Hz and 6 Hz, respectively) and amplitudes (i.e. 50%, 58% and 67% for 50 N, 80 N, and 100 N, respectively). In this study, the simulation model is validated with an experimental study in terms of natural frequency, mode shape and uncontrolled response at the 1st mode. The proposed PID-ACO control strategy and optimal MR damper position is also implemented on a lab-scaled wind turbine tower model. The results show that the vibration reduction rate is 66% and 73% in the experimental and simulation study, respectively, at the 1st mode.

Since wind power is directly influenced by wind speed, long-term wind speed forecasting (WSF) plays an important role for wind farm installation. WSF is essential for controlling, energy management and scheduled wind power generation in wind farm. The proposed investigation in this paper provides 30-days-ahead WSF. Nonlinear Autoregressive (NAR) and Nonlinear Autoregressive Exogenous (NARX) Neural Network (NN) with different network settings have been used to facilitate the wind power generation. The essence of this study is that it compares the effect of activation functions (namely, tansig and logsig) in the performance of time series forecasting since activation function is the core element of any artificial neural network model. A set of wind speed data was collected from different meteorological stations in Malaysia, situated in Kuala Lumpur, Kuantan, and Melaka. The proposed activation functions tansig of NARNN and NARXNN resulted in promising outcomes in terms of very small error between actual and predicted wind speed as well as the comparison for the logsig transfer function results.

The production of maximum wind energy requires controlling various parts of medium to large-scale wind turbines (WTs). This paper presents a robust pitch angle control system for the rated wind turbine power at a wide range of simulated wind speeds by means of a proportional–integral–derivative (PID) controller. In addition, ant colony optimization (ACO), particle swarm optimization (PSO), and classical Ziegler–Nichols (Z-N) algorithms have been used for tuning the PID controller parameters to obtain within rated stable output power of WTs from fluctuating wind speeds. The proposed system is simulated under fast wind speed variation, and its results are compared with those of the PID-ZN controller and PID-PSO to verify its effeteness. The proposed approach contains several benefits including simple implementation, as well as tolerance of turbine parameters and several nonparametric uncertainties. Robust control of the generator output power with wind-speed variations can also be considered a significant advantage of this strategy. Theoretical analyses, as well as simulation results, indicate that the proposed controller can perform better in a wide range of wind speed compared with the PID-ZN and PID-PSO controllers. The WT model and hybrid controllers (PID-ACO and PID-PSO) have been developed in MATLAB/Simulink with validated controller models. The hybrid PID-ACO controller was found to be the most suitable in comparison to the PID-PSO and conventional PID. The root mean square (RMS) error calculated between the desired power and the WT’s output power with PID-ACO is found to be 0.00036, which is the smallest result among the studied controllers.

Vibration in the wind turbine tower disturbs the reliability and increases the possibility of structural damage. Design and optimization of vibration controller are a key goal for wind turbine tower to achieve optimal performance. In this study, a proportional integral derivative (PID) is designed and optimized using nature technology to find optimal required force for actuators and therefore, reducing wind turbine tower vibration. PID controller parameters are optimized with ant colony optimization (ACO) and compared with traditional tuning methods such as Ziegler–Nichols and Tyreus–Luyben methods to ensure its effectiveness in minimizing wind turbine tower vibration. The optimized active vibration controller shows better performance than traditional method in terms of vibration reduction rate, ability to adapt when frequency varies and computational time. This paper also investigated finite difference method for wind turbine tower modeling, and its efficacy is compared with another well-known numerical finite element method based on mean squared error, fit to estimated data and cross signature assurance criterion. The performance of ACO optimized PID controller is investigated for wind turbine tower under four different types of disturbances and compared with uncontrolled and passive controlled system. Results show that 98, 84, 92 and 98% of displacement of the tower are reduced under simulated blade/rotor imbalance, impact, wind and turbulence disturbances, respectively, using ACO optimized PID controller.

This study aimed to modify the starch-based bioplastics with acceptable mechanical and water resistance properties using palm oil (PO) and epoxidized palm oil (EPO). The structural, thermal, mechanical and water resistance properties of the resulted bio-composites were evaluated. EPO had better compatibility within the starch matrix than PO. The bioplastics with PO and EPO exhibited different melting behaviors. Low concentrations of oils (

In recent years, magnetorheological (MR) fluid technology has received much attention and consequently has shown much improvement. Its adaptable nature has led to rapid growth in such varied engineering applications as the base isolation of civil structures, vehicle suspensions, and several bio-engineering mechanisms through its implementation in different MR fluid base devices, particularly in MR dampers. The MR damper is an advanced application of a semi-active device which performs effectively in vibration reduction due to its control ability in both on and off states. The MR damper has the capacity to generate a large damping force, with comparatively low power consumption, fast and flexible response, and simplicity of design. With reference to the huge demand for MR dampers, this paper reviews the advantages of these semi-active systems over passive and active systems, the versatile application of MR dampers, and the fabrication of the configurations of various MR dampers, and provides an overview of various MR damper models. To address the increasing adaptability of the MR dampers, their latest design optimization and advances are also presented. Because of the tremendous interest in self-powered and energy-saving technologies, a broad overview of the design of MR dampers for energy harvesting and their modeling is also incorporated in this paper.

This work reports synthesis, thin film characterizations, and study of an organic semiconductor 2-aminoanthraquinone (AAq) for humidity and temperature sensing applications. The morphological and phase studies of AAq thin films are carried out by scanning electron microscope (SEM), atomic force microscope (AFM), and X-ray diffraction (XRD) analysis. To study the sensing properties of AAq, a surface type Au/AAq/Au sensor is fabricated by thermally depositing a 60 nm layer of AAq at a pressure of ~10&minus, 5 mbar on a pre-patterned gold (Au) electrodes with inter-electrode gap of 45 &micro, m. To measure sensing capability of the Au/AAq/Au device, the variations in its capacitance and resistance are studied as a function of humidity and temperature. The Au/AAq/Au device measures and exhibits a linear change in capacitance and resistance when relative humidity (%RH) and temperature are varied. The AAq is a hydrophobic material which makes it one of the best candidates to be used as an active material in humidity sensors, on the other hand, its high melting point (575 K) is another appealing property that enables it for its potential applications in temperature sensors.

A large number of populations of the world; especially in developing countries; are living in rural or remote areas those are geographically isolated from the grid connection. Power supply and uninterrupted fuel transportation to produce electrical power for these areas poses a great challenge. Using renewable energy in off grid hybrid energy system might be a pathway to solve this problem. Malaysia is a hilly land with the gift of renewable energy resources. There is a possibility to utilize these renewable resources to produce electrical power and to limit the dependency on the fossil fuel. In this perspective, a research is carried out to analyze the performance of an off-grid PV (photovoltaic)-wind-diesel-battery hybrid energy system for a remote area named “KLIA Sepang Station” located in the state of Selangor, Malaysia. The system is designed as well as simulated to support a small community considering an average load demand of 33 kWh/day with a peak load of 3.9 kW. The simulation and optimization of operations of the system have been done by HOMER (Hybrid Optimization Model for Electric Renewable) software using the real time field data of solar radiation and wind speed of that area. The simulation ensures that the system is suitably feasible with respect to net present cost (NPC) and CO 2 emission reduction purpose. The result shows that NPC and CO 2 emission can be reduced about 29.65% and 16 tons per year respectively compared to the conventional power plants. The NPC of the optimized system has been found about USD 288,194.00 having the per unit Cost of Energy (COE) about USD 1.877/kWh. The analyzed hybrid energy system might be applicable for other region of the world where the climate conditions are similar.

Nanotechnology provides useful insights into the behavioural properties of materials from the nanoscale point of view, enabling researchers to develop new materials that were previously inconceivable. Cellulose is an ideal candidate for nanomaterial for nanotechnology because of its nanofibrillar structure, abundance, renewability, biodegradability and eco-friendly nature. Nanocrystalline cellulose materials have become the focus many studies related to these materials and their applications. This review summarises the current knowledge on the field of nanomaterials, focussing mainly on the rheological behaviour of polymer nanocomposites embedded with nanocrystalline cellulose. This review will enable better understanding of the use of nanocrystalline cellulose for the development and applications of cellulose nanocrystal-based nanocomposites.

Renewable energy becomes an asset to the world׳s energy resource for its eco-friendly and low cost energy production feature. As an important renewable energy source, wind turbine technology has become a significant contributor to the world energy production because of its feasible production cost, reliability and efficiency. Researchers are very active to optimize the effectiveness of wind turbines which may lead to increase the productivity of this source of energy. Vibration in the wind turbine system affects the productivity and thus reduces efficiency. Vibration of a system cannot be destroyed but can be reduced or converted to energy using appropriate strategies. Vibration control system improves structural response of wind turbines and reliability which has impact on lifetime of the components. Lowering the vibration amplitude of a system will provide a lesser amount of noise, assure user and operating comport, maintain the high performance and production efficiency. These will assist the system to prolong the lifetime of an industrial structure or machinery. Also vibration control enhances the performance of wind turbines providing suitable work environment without external disturbance. This paper presents an ample review on performance enhancement of the wind turbines by vibration mitigation. The aim of this review is to provide a concise point for researchers to assess the current trend to control vibration of wind turbines technology. This paper will focus on main vibration control techniques of wind turbine structures. It provides the applications of passive, active and semi-active and vibration control strategies for structures, especially for wind turbines. Besides, this paper reviews on damping devices needed for vibration mitigation of structures. These damping devices have been implemented extensively in wind turbines for increasing their efficiency by mitigating vibration. This paper also reviews and assesses the performance of different control policies to control the system input and power input of damping devices.

The electrification process of the remote areas and decentralized areas is being a vital fact for the improvement of its eco-tourism issues such as the Cameron Highland of Malaysia. Renewable energy (RE) resources can be used extensively to support and fulfill the demand of the expected loads of these areas. This article presents an analysis of a complete off-grid wind-diesel-battery hybrid RE model. The main objective of the present analysis is to visualize the optimum volume of systems capable of ful- filling the requirements of 85 kWh/day primary load in coupled with 8.7 kW peak for 2 residential hotels of Cameron Highlands. The hybrid power system can be effective for the tourists of that area as it is a decentralized region of Malaysia. The main motto of this analysis is to minimize the electricity unit cost and ensure the most reliable and feasible system to fulfill the requirements of the desired or expected energy system using HOMER software. From the simulation result, it can be seen that 15 wind turbines (10 kW), 1 diesel generator (4 kW), and 2 battery (Hoppecke 4 OPzS) hybrid RE system is the most economically feasible and lowest cost of energy is nearing USD 0.199/kWh and net present cost is USD 77, 019. The decrement of the CO2 emissions also can be identified from the simulation results using that most feasible RE system including the renewable fraction value which is about 0.0914, 0.3 % capacity shortage and 20.3 % electricity as storage as compared to the other energy system.

Smart fluids, known as smart material, are used to form controllable dampers in vibration control applications. Magnetorheological(MR) fluid damper is a well-known smart fluid damper which has a reputation to provide high damping force with low-power input. However, the force/velocity of the MR damper is significantly nonlinear and proper characteristic analysis are required to be studied for optimal implementation in structural vibration control. In this study, an experimental investigation is carried out to test the damping characteristics of MR damper. Dynamic testing is performed with a long-stroke MR damper model no RD-80410-1 from Lord corporation on a universal testing machine(UTM). The force responses of MR damper are measured under different stroke lengths, velocities and current inputs and their performances are analyzed. This study will play a key role to implement MR damper in many structural vibration control applications.

The energy harvesting (EH) from unused natural waste energy sources is common nowadays because of rising power demand. The sources have the potential of producing micro to milliwatts power depending on the ambient conditions. Many researchers have been concentrating on micro-level energy harvesting to provide power to the micro-devices in a remote area. The concept leads to a drastic reduction in cost. Once the structure is established, it can generate electricity with minimal cost or effort like renewable sources. This paper reviews the two key areas of the piezoelectric energy harvesting system (PEHS), namely, mechanical and electronic approaches, developed by several researchers. From the thorough review, it is realized that the existing technologies more or less can capable to EH by using the piezoelectric elements; however, the consistency and stability of the systems are not up to the mark yet. In this study, vibration-based PEHS has been considered for the application of the optimization technique to enhance its performance. This review has been focused on numerous challenges and recommendations for next-generation EH by utilizing vibration-based piezoelectric elements.

In this study microcrystalline cellulose (MCC) was oxidized by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation. The treated cellulose slurry was mechanically homogenized to form a transparent dispersion which consisted of individual cellulose nanofibers with uniform widths of 3-4 nm. Bio-nanocomposite films were then prepared from a polyvinyl alcohol (PVA)-chitosan (CS) polymeric blend with different TEMPO-oxidized cellulose nanofiber (TOCN) contents (0, 0.5, 1.0 and 1.5 wt %) via the solution casting method. The characterizations of pure PVA/CS and PVA/CS/TOCN films were performed in terms of field emission scanning electron microscopy (FESEM), tensile tests, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results from FESEM analysis justified that low loading levels of TOCNs were dispersed uniformly and homogeneously in the PVA-CS blend matrix. The tensile strength and thermal stability of the films were increased with the increased loading levels of TOCNs to a maximum level. The thermal study indicated a slight improvement of the thermal stability upon the reinforcement of TOCNs. As evidenced by the FTIR and XRD, PVA and CS were considered miscible and compatible owing to hydrogen bonding interaction. These analyses also revealed the good dispersion of TOCNs within the PVA/CS polymer matrix. The improved properties due to the reinforcement of TOCNs can be highly beneficial in numerous applications.

This paper presents the development of an active vibration control (AVC) system with distributed disturbances using genetic algorithms, particle swarm optimization, and ant colony optimization. The approaches are realized with multiple-input multiple-output and multiple-input single-output control configurations in a flexible plate structure. A simulation environment characterizing a thin, square plate, with all edges clamped, is developed using the finite difference method as a platform for test and verification of the developed control approaches. Simulations are carried out with random disturbance signal. The control design comprises a direct minimization of the error (observed) signal by allowing a collective determination of detection and secondary source locations together with controller parameters. The algorithms are formulated with a fitness function based on the mean square of the observed vibration level. In this manner, knowledge of the input/output characterization of the system is not required for design of the controller. The performance of the system is assessed and analyzed both in the time and frequency domains and it is demonstrated that significant vibration reduction is achieved with the proposed schemes.

Interest in biologically-inspired optimization techniques has increased due to its accurate results, fast performance and ease of use. In this paper, an ant colony optimization (ACO) technique is deployed and used for modelling a twin rotor system. The system is perceived as a challenging engineering problem due to its strong cross coupling between horizontal and vertical axes and inaccessibility of some of its states and outputs for measurements. Accurate modelling of the system is thus required so as to achieve satisfactory control objectives. It is demonstrated that ACO can be effectively used for modelling the system with highly accurate results. The accuracy of the modelling results is demonstrated through validation tests including training and test validation and correlation tests.

This paper presents investigations of modeling the flexible plate structures using particle swarm optimization (PSO) and active vibration control (AVC) of such structures. The optimization technique is utilized to obtain a dynamic model of a flexible plate structure based on auto-regressive with exogenous (ARX) input structure. The structure is subjected to two different disturbance signal types, namely random, and finite duration step. The fitness function for the PSO is the mean-squared error (MSE) between the measured and estimated outputs of the plate. The validation of the algorithm is presented in both time and frequency domains. The developed PSO modeling approach is used for AVC system design to suppress the vibration of the flexible plate. The performance of the controller is assessed in terms of level of attenuation achieved in the power spectral density (PSD) of the observed signal.

This paper presents the development of an active vibration control (AVC) mechanism using real-coded genetic algorithm (RCGA) optimization. The approach is realized with single-input single-output (SISO) and single-input multiple-output (SIMO) control configurations in a flexible plate structure. A simulation environment characterizing a thin, square plate, with all edges clamped, is developed using the finite difference (FD) method as a platform for test and verification of the developed control approach. Tests are carried out with different disturbance signal types, namely random and finite duration step. The control design comprises a direct optimization of the controller parameters based on minimization of the error (observed) signal. The RCGA is formulated with a fitness function based on mean square of the observed vibration. The performance of the system is assessed and analysed both in the time and frequency domains and it is demonstrated that the proposed scheme reduces vibration of the flexible plate significantly.

This paper presents parametric modelling of flexible plate structures using real-coded genetic algorithms (RCGA). The global optimization technique of RCGA is utilized to obtain a dynamic model of a flexible plate structure based on one-step-ahead (OSA) prediction. The structure is subjected to three different disturbance signal types, namely random, pseudo random binary sequence (PRBS), and finite duration step. The fitness function for the RCGA optimization is the mean-squared error (MSE) between the measured and estimated outputs of the plate. The validation of the algorithm is presented in both time and frequency domains. The developed RCGA modelling approach will be used for active vibration control systems design and development in future work.

An investigation on control mechanism using particle swarm optimization (PSO) to suppress the vibration of flexible plate has been carried out. Active vibration control (AVC) is implemented for the case of single-input single output (SISO), and the controller is realized in linear parametric form where all parameters are arbitrarily chosen by applying the working mechanism of PSO. The objective function is the mean-squared error of the observed vibration signal. The performance of the controller is assessed in terms of level of attenuation achieved in the power spectral density (PSD) of the observed signal.

This paper presents investigations into modeling and active vibration control (AVC) of a flexible plate structure using continuous ant system algorithm (CASA) such structures. The optimization technique is utilized to obtain a dynamic model of a flexible plate structure based on auto-regressive with exogenous (ARX) input model structure. The flexible plate structure is subjected to two different disturbance signal types, namely random, and finite duration step. The fitness function for the CASA is the mean-squared error (MSE) between the measured and estimated outputs of the plate. The validation of the algorithm is presented in both time and frequency domains. The developed CASA modeling approach is used for AVC system design to suppress the vibration of the flexible plate. The performance of the controller is assessed in terms of level of attenuation achieved in the power spectral density of the observed signal.