Real-time Thermal Energy Harvesting from Solar Radiation in Malaysia at Low-Temperature Difference Muhammad Nazri Rejab, Omar Mohd Faizan Marwah, Muhammad Akmal Johar, Mohamed Najib Ribuan Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2023 .Malaysia is located in a tropical climate with an abundance of solar radiation. Due to the low albedo of roofing material, around 20 % to 90 % of heat is absorbed from solar radiation. Thus, it is possible to harvest thermal energy from solar radiation using TEG, which promotes the diversity of renewable energy sources in Malaysia. Previous research evaluates the potential of thermal energy harvesting of the TEG open circuit voltage and unipolar condition. Thereby, this research focuses on designing and developing a thermal energy harvesting system (TEHS) for harvesting thermal energy at low-temperature differences from solar radiation. The TEHS can harvest thermal energy in bipolar conditions, different voltage levels, TEG input voltage fluctuations, and rapid weather-changing conditions during real-time field tests. Parallel with series balance TEG array configuration obtained impedance matching at 125 Ω. The field test method was conducted for 105 days. The maximum mean efficiency obtained is 94.33 %, with an output power range between 0.46 mW and 66.10 mW. The promising finding indicates that the developed TEHS is robust and capable of operating at optimum power transfer at uncontrollable solar radiation and weather conditions. In addition, the potential of the power generated evaluation is to be used as a power supply to several sensor nodes.
Dual-Level Voltage Bipolar Thermal Energy Harvesting System from Solar Radiation in Malaysia Muhammad Nazri Rejab, Omar Mohd Faizan Marwah, Muhammad Akmal Johar, Mohamed Najib Ribuan Sustainability Switzerland, 2022 Harvesting energy from solar radiation in Malaysia attracts the attention of researchers to utilize the potential by ongoing improvement. Roofing material with low albedo absorbs the heat, that can then be harvested using a thermoelectric generator. Previous research only measured the open-circuit voltage with different thermoelectric generator configurations. Low power output limits the potential to be utilized. The low output power can be increased using a DC converter. However, the converter must be tuned concerning low- and high-voltage levels, bipolar, and the maximum power point tracking. Therefore, this paper presents a dual-level voltage bipolar (DLVB) thermal energy harvesting system. The circuit is tested at constant and various time intervals to evaluate the system’s functionality and performance. Experiment results show that the proposed harvesting system can boost from 0.6 and 1.6 V to achieve the optimum level. The mean efficiency of the harvesting circuit obtains 91.92% at various time intervals. Further, the field test result obtains output power from 1.45 to 66.1 mW, with the mean efficiency range of 89.62% to 92.98%. Furthermore, recommendations are listed for future research.
Perturb and Observe Parameter Tuning to Harvest Thermal Energy from Solar Radiation at Rooftop and Attic Area: A Comparative Study Muhammad Nazri Rejab, Muhammad Akmal Johar Applied Solar Energy English Translation of Geliotekhnika, 2022 Abstract Solar radiation generates thermal energy in the roof and attic area. The thermoelectric generator is used to convert thermal energy into electrical energy. Perturb and Observe algorithm used in the thermal energy harvesting system to obtain the maximum power point. However, the algorithm’s performance depends on the frequency and duty cycle parameters. Therefore, parameter tuning is necessary regarding real-time experimental data. Using MATLAB Simulink simulation, different frequency and duty cycle step size values are evaluated based on the oscillation range, efficiency, output power, and power losses. Simulation results indicated that 55 kHz frequency obtained 87.53% efficiency with a 0.0012 oscillation range. Furthermore, combining the frequency with duty cycle step size increases the efficiency to 88.79%. In contrast, the temperature fluctuation significantly affects the efficiency and power losses due to the sudden decline at the maximum power point. The overall result shows a significant effect of frequency and duty cycle step size to obtain the MPP. An implication is the feasibility of thermal energy harvesting from solar radiation by designing and developing a thermal energy harvesting circuit.
Evaluation of thermoelectric generator array configuration for thermal energy harvesting at the rooftop and attic area due to solar radiation in Malaysia Muhammad Nazri Rejab, Muhammad Akmal Johar Proceedings of the 2022 International Electrical Engineering Congress Ieecon 2022, 2022 Solar radiation at the rooftop and attic area generated potential thermal energy. Thereby, TEG utilizes to harvest the thermal energy. However, the effect of TEG array configuration combined with different load resistance to the real-time temperature difference is evaluated. Furthermore, MATLAB Simulink was used to evaluate the array configuration of the performance in terms of output power according to the real-time data from the experiment. The absolute data analysis deals with bipolar temperature values, thus obtaining accurate results. Furthermore, the impedance matching of the TEG array configuration was determined to achieve optimal power transfer. In comparison, parallel configuration shows higher energy with 190 % than series. Interestingly, the morning and evening sections proved the availability of potential thermal energy at the attic area that can be harvested. Furthermore, the result indicates that the DC converter is needed to enhance the energy harvested.
Rooftop and Attic Area Thermal Energy from Solar Radiation as Renewable Energy in Malaysia Muhammad Nazri Rejab, Muhammad Akmal Johar, Wan Akashah Wan Jamaludin, Umar Abubakar Saleh 2021 9th International Conference on Smart Grid and Clean Energy Technologies Icsgce 2021, 2021 Uncomplicated thermoelectric generator setup used to determine the potential thermal energy harvesting at roof and attic area due to the solar radiation for 20 days. A theoretical method is used to determine the output power due to the temperature difference at the thermoelectric generator module. The equivalent load resistance value refers to the thermoelectric generator array configuration. From the result, the attic area shows the potential of thermal energy that can be harvested due to the slow convection of heat to the surrounding. In addition, the effect of solar radiation at the day section is observed.
Evaluation of a pv-teg hybrid system configuration for an improved energy output: A review Umar Abubakar Saleh, Muhammad Akmal Johar, Siti Amely Binti Jumaat, Muhammad Nazri Rejab, Wan Akashah Wan Jamaludin International Journal of Renewable Energy Development, 2021 The development of renewable energy, especially solar, is essential for meeting future energy demands. The use of a wide range of the solar spectrum through the solar cells will increase electricity generation and thereby improve energy supply. However, solar photovoltaics (PV) can only convert a portion of the spectrum into electricity. Excess solar radiation is wasted by heat, which decreases solar PV cells’ efficiency and decreases their life span. Interestingly, thermoelectric generators (TEGs) are bidirectional devices that act as heat engines, converting the excess heat into electrical energy through thermoelectric effects through when integrated with a PV. These generators also enhance device efficiency and reduce the amount of heat that solar cells dissipate. Several experiments have been carried out to improve the hybrid PV-TEG system efficiency, and some are still underway. In the present study, the photovoltaic and thermoelectric theories are reviewed. Furthermore, different hybrid system integration methods and experimental and numerical investigations in improving the efficiency of PV-TEG hybrid systems are also discussed. This paper also assesses the effect of critical parameters of PV-TEG performance and highlights possible future research topics to enhancing the literature on photovoltaic-thermoelectric generator systems.
Neural network performance comparison in infant pain expression classifications Muhammad Naufal Mansor, Mohd Nazri Rejab Applied Mechanics and Materials, 2014 Infant pain is a non-stationary made by infants in response to certain situations. This infant facial expression can be used to identify physical or psychology status of infant. The aim of this work is to compare the performance of features in infant pain classification. Fast Fourier Transform (FFT), and Singular value Decomposition (SVD) features are computed at different classifier. Two different case studies such as normal and pain are performed. Two different types of radial basis artificial neural networks namely, Probabilistic Neural Network (PNN) and General Regression Neural Network (GRNN) are used to classify the infant pain. The results emphasized that the proposed features and classification algorithms can be used to aid the medical professionals for diagnosing pathological status of infant pain.
A robust neonatal facial pain cues classification Muhammad Naufal Mansor, Mohd Nazri Rejab Applied Mechanics and Materials, 2014 Late of infant pain detection on the early stage may affect newborns growth. Regarding of this matter, different techniques have been proposed such as facial expressions, speech production variation, and physiological signals to detect the pain states of a person. For past 2 decades, the determination of pain state through images has been undergone substantial research and development. Various techniques are used in the literature to classify pain states on the basis of images. In this paper, a feature extraction method using Principal Component Analysis (PCA) was adopted for identifying the pain states of an infant. In this study images samples are taken from Classification of Pain Expressions (COPE) database. Fuzzy k-NN, k Nearest Neighbor (k-NN), Feed Forward Neural network (FFNN) and Linear Discriminant analysis (LDA) based classifier is used to test usefulness of suggested features. Experimental result shows that the suggested methods can be used to identify the pain states of an infant.
Innovative concepts for newborn pain based systems with Hu moment and similar classifier Muhammad Naufal Mansor, Mohd Nazri Rejab Applied Mechanics and Materials, 2014 Image analysis of infant pain has been proven to be an excellent tool in the area of automatic detection of pathological status of an infant. This paper investigates the application of parameter weighting for invariant moments to provide the robust representation of infant pain images. Two classes of infant images were considered such as normal images, and babies in pain. A Similar Classifier is suggested to classify the infant images into normal and pathological images. Similar Classifier is trained with different spread factor or smoothing parameter to obtain better classification accuracy. The experimental results demonstrate that the suggested features and classification algorithms give very promising classification accuracy of above 89.54% and it expounds that the suggested method can be used to help medical professionals for diagnosing pathological status of an infant from face images.
Analysis of mechanical properties for 2D woven kenaf composite Md. Saidin Wahab, Muhammad Nazri Rejab, Mohd Pahmi Saiman Applied Mechanics and Materials, 2014 Woven composite based on natural fiber increasingly used for many applications in industries because of their advantages such as good relative mechanical properties and renewable resources, but there are some issues as cost and protracted development period to perform reliability evaluation by experimental with real scale. Predictive modeling technique is use to minimize the need for physical testing, shorten design timescales and provide optimized designs. Mechanical properties of woven fabrics for technical textile depend on a) type of raw materials b) type and count of warp and weft yarns c) yarn density and d) the type of weave structure. The effect of fabric architecture to the mechanical properties is investigated. Woven kenaf composite is modeled using the modeling software to get the properties of the model. Further, the model is analyzed using finite element analysis to predict the mechanical properties of the woven kenaf composite. In addition, the effect of the combination of yarn size and weave pattern to the woven kenaf composite is stated base on the mechanical properties to predict the optimum structure of woven kenaf composite.
Fuzzy k-NN and k-NN algorithm for fast infant cues detection M. N. Mansor, S. Yaacob, M. Hariharan, S. N. Basah, S. H. F. S. Ahmad Jamil, M. L. Mohd Khidir, M. N. Rejab, K. M. Y. Ku Ibrahim, A. H. F. S. Ahmad Jamil, J. Ahmad, A. K Junoh Ifmbe Proceedings, 2013
Clinical infant pain trial based on k-NN algorithm Muhammad Naufal Mansor, Syahrull Hi-Fi Syam, Muhammad Nazri Rejab, Addzrull Hi-Fi Syam B Proceedings 2012 International Symposium on Instrumentation and Measurement Sensor Network and Automation Imsna 2012, 2012
AR model for infant pain anxiety recognition using fuzzy k-NN Muhammad Naufal Mansor, Muhammad Nazri Rejab, Syahrull Hi-Fi Syam, Addzrull Hi-Fi Syam B Proceedings 2012 International Symposium on Instrumentation and Measurement Sensor Network and Automation Imsna 2012, 2012
Early choke infant monitoring scheme Muhammad Naufal Mansor, Shahryull Hi-Fi Syam Mohd Jamil, Mohd Nazri Rejab, Addzrull Hi-Fi Syam Mohd Jamil Proceedings 2012 International Symposium on Instrumentation and Measurement Sensor Network and Automation Imsna 2012, 2012
Automatically infant pain recognition based on LDA classifier Muhammad Naufal Mansor, Muhammad Nazri Rejab, Syahrull Hi-Fi Syam, Addzrull Hi-Fi Syam B Proceedings 2012 International Symposium on Instrumentation and Measurement Sensor Network and Automation Imsna 2012, 2012
Fuzzy k-NN for choke infant detection Muhammad Naufal Mansor, Shahryull Hi-Fi Syam Mohd Jamil, Mohd Nazri Rejab, Addzrull Hi-Fi Syam Mohd Jamil Proceedings 2012 International Symposium on Instrumentation and Measurement Sensor Network and Automation Imsna 2012, 2012
Neonates suffocated recognition based on LDA algorithm Muhammad Naufal Mansor, Shahryull Hi-Fi Syam Mohd Jamil, Mohd Nazri Rejab, Addzrull Hi-Fi Syam Mohd Jamil Proceedings 2012 International Symposium on Instrumentation and Measurement Sensor Network and Automation Imsna 2012, 2012
K-nn algorithm for fast infant pain detection Muhammad Naufal Mansor, Shahryull Hi-Fi Syam Mohd Jamil, Mohd Nazri Rejab, Addzrull Hi-Fi Syam Mohd Jamil Proceedings 2012 International Symposium on Instrumentation and Measurement Sensor Network and Automation Imsna 2012, 2012
Pain assessment using neural network classifier Muhammad Naufal Mansor, Syahrull Hi-Fi Syam, Muhammad Nazri Rejab, Addzrull Hi-Fi Syam B Proceedings 2012 International Symposium on Instrumentation and Measurement Sensor Network and Automation Imsna 2012, 2012
Fast infant pain detection method Muhammad Naufal Mansor, Syahryull Hi-Fi Syam Ahmad Jamil, Ahmad Kadri Junoh, Muhammad Nazri Rejab, Addzrull Hi-Fi Syam Ahmad Jamil, Jamaluddin Ahmad 2012 International Conference on Computer and Communication Engineering Iccce 2012, 2012
Preemies birth monitoring using color detection method M.N. Mansor, S. Yaacob, M. Hariharan, S.N. Basah, S.H.F.S. Ahmad Jamil, M.L. Mohd Khidir, M.N. Rejab, K.M.Y Ku Ibrahim, A.H.F.S. Ahmad Jamil, A.K Junoh Procedia Engineering, 2012
Jaundice in newborn monitoring using color detection method M.N. Mansor, S. Yaacob, M. Hariharan, S.N. Basah, S.H.F.S. Ahmad Jamil, M.L. Mohd Khidir, M.N. Rejab, Ku K.M.Y. Ibrahim, A.H.F.S. Ahmad Jamil, A.K. Junoh, S.A. Saad Procedia Engineering, 2012
Study of quiver infant level with LDA M.N. Mansor, S. Yaacob, M. Hariharan, S.N. Basah, S.H.F.S. Ahmad Jamil, M.L. Mohd Khidir, M.N. Rejab, K.M.Y. Ku Ibrahim, A.H.F.S. Ahmad Jamil, A.K. Junoh Procedia Engineering, 2012
Automatic infant anxiety character with SVM M.N. Mansor, S. Yaacob, M. Hariharan, S.N. Basah, S.H.F.S. Ahmad Jamil, M. L. Mohd Khidir, M.N. Rejab, K.M.Y Ku Ibrahim, A.H.F.S. Ahmad Jamil, A.K. Junoh Procedia Engineering, 2012
