Factorial analysis of lignocellulosic content influence on the permittivity of coconut-shell epoxy dielectric composites K. B. Mekha, Nur Sofia Idayu Didik Aprianto, K. Sudhakar, Norazwina Zainol, Nurulfadzilah Hasan, et al. Journal of King Saud University Engineering Sciences, 2026 The development of sustainable dielectric materials is crucial for advancing next-generation electronic and energy storage systems. This study investigates the dielectric behavior of coconut-shell-based epoxy composites and evaluates the influence of processing parameters using a two-level factorial design (TLFD) coupled with two-level factorial analysis (TLFA). The effects of filler loading, particle size, and curing condition (non-heated and heated) on lignocellulosic content and the real part of permittivity (ε′) were systematically examined at 5 GHz using a vector network analyzer. At a 40 wt.% filler content, the measured lignocellulosic content reached 58.7% (Kurschner-Hanack), with permittivity values ranging from 3.74 to 4.11. Statistical analysis identified the curing condition as the most significant factor affecting ε′, followed by filler loading and particle size. The novelty of this study lies in applying TLFD and TLFA to quantitatively evaluate how lignocellulosic content influences GHz-range permittivity specifically in coconut-shell-based dielectric composites, a compositional factor that earlier coconut-shell studies have not explicitly examined. This approach demonstrates how statistical modeling, supported by ANOVA, can bridge the relationship between material composition and electromagnetic performance in GHz dielectric composites. The findings establish a systematic framework for optimizing bio-based dielectric materials and demonstrate the potential of coconut-shell-derived composites for sustainable electronic applications.
5 GHz Microstrip Patch Antenna from Pineapple Leaf-Based Substrate for Environmentally Sustainable Wireless Communication Azahani Natasha Azman, Rudraa Devi Giamasrow, Nurfarhana Mustafa, Nurhafizah Abu Talip Yusof, Norazwina Zainol, et al. Journal of Advanced Research in Applied Sciences and Engineering Technology, 2025 Pineapples generate approximately 75% waste, each with its unique characteristics. Pineapple leaves have the potential to be utilized in the development of new fibres or raw materials. This study aims to present the design of a microstrip patch antenna that utilizes a pineapple leaf substrate to achieve a 5 GHz frequency resonant. The antenna design was simulated using CST software. The manufacturing process of the pineapple leaf substrate involves boiling, drying, blending, filtering, and mixing composite compositions. The dielectric permittivity at a frequency of G-band was determined using the waveguide technique, revealing an outstanding permittivity of 5.03 at 5 GHz. Subsequently, a microstrip patch antenna was fabricated and characterized to validate the concept. The results demonstrate an acceptable agreement between the simulation and the fabricated substrate at 5 GHz in term of return loss.
Potential of wastewater quality assessment using electronic sensors: A review Karim M.S. Abdul, N.A.T. Yusof, N. Zainol, N.H. Aziz Research Journal of Chemistry and Environment, 2025 Untreated wastewater and improper wastewater treatment from domestic and industrial sources continue to degrade water quality around the globe. The greatest challenge currently lies in shifting our perspective on wastewater, aiming to perceive it not merely as a problem but as a potential solution. Several challenges have limited wastewater monitoring and assessment. These limitations include real-time monitoring and aging infrastructure, which can impact the accuracy, efficiency and reliability of the obtained information. These conventional assessment methods are unable to handle the increasing volume and complexity of contaminants in modern wastewater, resulting in poorly treated wastewater. To address this issue, an electronic sensor has been introduced to overcome such crises, providing a better assessment of wastewater quality. Electronic sensors offer a real-time and efficient means to evaluate various parameters in wastewater, providing valuable insights into the composition and potential environmental impact. The potential of wastewater quality assessment using electronic sensors represents a promising avenue in modern environmental monitoring. This innovative approach allows for continuous and automated monitoring, enabling timely detection of changes in water quality. The utilization of electronic sensors in wastewater assessment holds the potential to enhance our understanding of pollution sources, to facilitate rapid responses to environmental challenges and to contribute to the sustainable management of water resources. In this review, a comprehensive study was performed on electronic sensors to evaluate their physical and chemical properties, as well as a microbial analysis for wastewater quality assessment. Possible challenges and future directions for their development have also been investigated critically. This study will assist future research on electronic sensors which will be highly important for sustainable wastewater assessment.
Design and Performance Optimization of a 3D-Printed SIW Antenna for Free-Space Applications Md Mahabub Alam, Nurhafizah Abu Talip Yusof, Nurazyyati Inas, Muhammad Naim Aminuddin, Bifta Sama Bari, et al. Diyala Journal of Engineering Sciences, 2025 This paper presents the design and performance evaluation of a Substrate-Integrated Waveguide (SIW) antenna fabricated using 3D printing technology, with a focus on optimizing its performance for future free-space applications. The proposed antenna integrates an SIW structure with a horn antenna concept, effectively combining the transmitter and receiver functions into a compact, monolithic substrate. This approach provides a miniaturized alternative to conventional free-space material characterization setups, leveraging SIW technology to replace bulky horn antennas with integrated structures. The study demonstrates the feasibility of compact free-space techniques for non-destructive testing, sensing, and electromagnetic material characterization applications. The study involves modeling and simulation using Computer Simulation Technology (CST) software, focusing on antenna performance in the G-band range (4–6 GHz). The fabricated prototype demonstrates resonant frequencies at 5.02 GHz and 6.0 GHz, with a scattering parameter below -10 dB and a well-defined radiation pattern, exhibiting sidelobes at -2.7 dB. The antenna is fabricated using biodegradable Polylactic Acid (PLA) material, reinforcing the potential for sustainable electronics while maintaining structural integrity and electromagnetic compatibility. While this study does not yet validate the antenna for material characterization, the results confirm its feasibility as a compact, cost-effective alternative to conventional free-space setups. This work lays the foundation for further optimization and experimental validation, advancing the role of 3D-printed SIW antennas in free-space applications.
Design of resonator cavity for liquid material characterization Nur Shahira Mat Hussain, Azahani Natasha Azman, Nurhafizah Abu Talip Yusof, Nur Alia Athirah Hj Mohtadzar, Mohamad Shaiful Abdul Karim Telkomnika Telecommunication Computing Electronics and Control, 2022
Development of Microwave Antenna for Cancer Treatment Nurfarhana Mustafa, Nur Hazimah Syazana Abdul Razak, Nurhafizah Abu Talip Yusof, Mohamad Shaiful Abdul Karim Advances in Intelligent Systems and Computing, 2021
Preface Lecture Notes in Electrical Engineering, 2020
Wearable Coaching System Nur Alia Athirah Hj Mohtadzar, Dyg Norkhairunnisa Abang Zaidel, Abdul Rahman Kram, Kasumawati Lias, Shahrol Mohamaddan, et al. International Journal of Integrated Engineering, 2020
A review on factors affecting heat transfer efficiency of nanofluids for application in plate heat exchanger Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2019
A review on thin layered composite zeolite for water desalination applications Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2019
Determination of complex permittivity of materials in rectangular waveguides using a hybrid electromagnetic method Cem 2013 Computational Electromagnetics International Workshop, 2013
Physics-Informed Artificial Neural Network-Based Estimation of Dielectric Properties for Resonant Method NSID Aprianto, SM Shaharum, N Mustafa, AAM Faudzi, ASM Shah, ... Applications of Modelling and Simulation 10, 120-129 , 2026 2026
Green-synthesised biodegradable, recyclable Zn (II) complex-based polymer electrolytes for electrochemical capacitor applications AA Adam, N Zainol, H Soleimani, MF Shukur, MSA Karim Microchemical Journal, 118257 , 2026 2026
Trends and prospects in solution-cast polymer electrolytes: From processing simplicity to performance complexity AA Adam, N Zainol, TA Manfo, MSA Karim Journal of Energy Storage 153, 120896 , 2026 2026 Citations: 2
Design and optimization of a high-efficiency circular SIW patch antenna for satellite communication MM Alam, MS Rahman, MSA Karim, YA Wahab, NAT Yusof Digital Communications and Networks , 2026 2026
Factorial analysis of lignocellulosic content influence on the permittivity of coconut-shell epoxy dielectric composites KB Mekha, NSID Aprianto, K Sudhakar, N Zainol, N Hasan, MSA Karim, ... Journal of King Saud University–Engineering Sciences 38 (2), 17 , 2026 2026
A Comprehensive Review of Maritime Wireless Propagation: Salinity, Humidity, and Evaporation Duct Effects on 5G/6G Networks IE Elmutasim, II Mohd, KH Bilal, M Hassan, NSID Aprianto, MSA Karim IEEE Access , 2026 2026
Properties of rice husk ash as a potential microwave absorber material SA Harun, MRSM Rooshdey, MA Jusoh, N Alias, MSA Karim AIP Conference Proceedings 3384 (1), 060001 , 2025 2025
Formulation of Dielectric Composite Material from Ananas Comosus Waste for 5 GHz Microstrip Antenna NSID Aprianto, MK Zakarzan, NAT Yusof, N Hasan, MSA Karim Solid State Phenomena 372, 13-19 , 2025 2025 Citations: 1
Surface analysis of pineapple leaves pulp-based dielectric composite material and its dielectric performance MSA Karim, N Zainol, NH Aziz, MJM Fikry, NAT Yusof Next Materials 8, 100706 , 2025 2025
Design and optimization of Π-shaped slotted dual-band SIW antenna for 5G applications MM Alam, NAT Yusof, YA Wahab, MSA Karim, MS Rahman Applications of Modelling and Simulation 9, 92-106 , 2025 2025 Citations: 7
Design and Performance Optimization of a 3D-Printed SIW Antenna for Free-Space Applications MM Alam, NAT Yusof, N Inas, MN Aminuddin, BS Bari, YA Wahab, ... Diyala Journal of Engineering Sciences, 170-191 , 2025 2025 Citations: 8
Development of sustainable polymer-based dielectric composites from agricultural waste: A review KB Mekha, NAT Yusof, K Sudhakar, N Zainol, N Hasan, MSA Karim Heliyon 10 (21) , 2024 2024 Citations: 12
A Development of a Dielectric Composite Substrate Based on Barium Titanate-Epoxy Resin for a 5 GHz Microstrip Antenna NSID Aprianto, NIIM Nadzri, N Mustafa, MHA Ab Malek, AAM Faudzi, ... Proceedings of International Exchange and Innovation Conference on … , 2024 2024 Citations: 2
Factorial Analysis on the Preparation of Barium Titanate-Epoxy Resin Composite for Antenna Substrate. NSID Aprianto, N Hasan, NIIM Nadzri, N Mustafa, AAM Faudzi, NAT Yusof, ... Progress in Electromagnetics Research C 147 , 2024 2024 Citations: 1
Epoxy-Barium Titanate Nanocomposite Substrate for Wi-Fi Applications MSA Karim, NA Talip Proceedings of the 7th International Conference on Electrical, Control and … , 2024 2024
Factorial analysis on the preparation of pineapple plantation waste as dielectric materials NFN Rasid, N Zainol, A Ya’acob, KA Samad, NAT Yusof, NH Aziz, ... Biomass Conversion and Biorefinery 14 (16), 19637-19648 , 2024 2024 Citations: 9
Dielectric material preparation from pineapple leaf fiber based on two-level factorial analysis and its morphological structure MSA Karim, N Zainol, NH Aziz, NSM Hussain, NAT Yusof Journal of Engineering Research 12 (2), 25-33 , 2024 2024 Citations: 12
Fabrication of Cellulose Powder Dielectric Composite Material using Pineapple Leaves Fiber RD Giamasrow, NAT Yusof, AN Azman, N Zainol, MSA Karim Journal of Advanced Research in Applied Sciences and Engineering Technology … , 2024 2024 Citations: 7
Design and analysis of triple-band SIW antenna for K-Band and Ka-Band applications MA MD, AMF AHMAD, MS SYAMIMI, AW YASMIN, HAABM MUHAMMAD, ... PROCEEDINGS OF INTERNATIONAL EXCHANGE AND INNOVATION CONFERENCE ON … , 2024 2024 Citations: 5
5 GHz Microstrip Patch Antenna from Pineapple Leaf-Based Substrate for Environmentally Sustainable Wireless Communication AN Azman, RD Giamasrow, N Mustafa, NAT Yusof, N Zainol, ... Journal of Advanced Research in Applied Sciences and Engineering Technology … , 2024 2024 Citations: 4
MOST CITED SCHOLAR PUBLICATIONS
A triangular MIMO array antenna with a double negative metamaterial superstrate to enhance bandwidth and gain R Ojo, MF Jamlos, PJ Soh, MA Jamlos, N Bahari, YS Lee, SS Al‐Bawri, ... International Journal of RF and Microwave Computer‐Aided Engineering 30 (8 … , 2020 2020 Citations: 34
Dielectric properties of epoxy–barium titanate composite for 5 GHz microstrip antenna design N Hasan, NH Noordin, MSA Karim, MRM Rejab, QJ Ma SN Applied Sciences 2 (1), 62 , 2020 2020 Citations: 33
A review on factors affecting heat transfer efficiency of nanofluids for application in plate heat exchanger H Ibrahim, N Sazali, ASM Shah, MSA Karim, F Aziz, WNW Salleh Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 60 (1 … , 2019 2019 Citations: 33
Determination of complex permittivities of layered materials using waveguide measurements MSBA Karim, Y Konishi, K Harafuji, T Kitazawa IEEE transactions on Microwave Theory and Techniques 62 (9), 2140-2148 , 2014 2014 Citations: 32
Effect of processing parameters on cellulose content extracted from pineapple leaf MSA Karim, N Zainol, NIAAH As’ari, NAT Yusof, NH Aziz Biocatalysis and Agricultural Biotechnology 42, 102339 , 2022 2022 Citations: 22
Robustness analysis of simultaneous determination method of complex permittivity and permeability MSBA Karim, Y Konishi, T Kitazawa 2014 international conference on numerical electromagnetic modeling and … , 2014 2014 Citations: 19
Non-invasive blood glucose concentration level estimation accuracy using ultra-wide band and artificial intelligence M Islam, MS Ali, NJ Shoumy, S Khatun, MSA Karim, BS Bari SN Applied Sciences 2 (2), 278 , 2020 2020 Citations: 18
Application of soda pulping method in cellulose extraction process from pineapple leaf MSA Karim, N Zainol, NIAAH As' ari, NSM Hussain, NH Aziz Materials Today: Proceedings 57, 1208-1214 , 2022 2022 Citations: 16
Software module development for non-invasive blood glucose measurement using an ultra-wide band and machine learning M Islam, CL Min, NJ Shoumy, MS Ali, S Khatun, MSA Karim, BS Bari Journal of Physics: Conference Series 1529 (5), 052066 , 2020 2020 Citations: 15
Cured epoxy resin dielectric characterization based on accurate waveguide technique N Hasan, NSM Hussain, AAM Faudzi, SM Shaharum, NAT Yusof, ... AIP conference proceedings 2129 (1), 020080 , 2019 2019 Citations: 15
Scattering analysis of rectangular cavity with input and output waveguides and its application to material characterization MSBA Karim, NBAT Yusof, T Kitazawa 2017 IEEE Asia Pacific Microwave Conference (APMC), 588-591 , 2017 2017 Citations: 15
Design of resonator cavity for liquid material characterization NSM Hussain, AN Azman, NAT Yusof, NAAH Mohtadzar, MSA Karim TELKOMNIKA (Telecommunication Computing Electronics and Control) 20 (2), 447-454 , 2022 2022 Citations: 14
An accurate characterization of different water properties using resonant method for underwater communication activity S Awang Akbar, AS Mohd Shah, AS Abdullah, N Abu Talip Yusof, ... Proceedings of the 10th National Technical Seminar on Underwater System … , 2019 2019 Citations: 14
A method of evaluating high-permittivity and lossy materials using a cylindrical cavity based on hybrid electromagnetic theory M Kinoshita, H Kinouchi, MSBA Karim, K Wakino, T Kitazawa Japanese Journal of Applied Physics 51 (9S1), 09LF03 , 2012 2012 Citations: 14
Dielectric materials development using bio-waste: a review N Zainol, N Mustafa, NH Aziz, AN Azman, MS Abdul Karim Journal of Electrical Systems and Information Technology 10 (1), 47 , 2023 2023 Citations: 13
Effect of fiber morphology and elemental composition of Ananas comosus leaf on cellulose content and permittivity NAT Yusof, N Zainol, NH Aziz, MSA Karim Current Applied Science and Technology, 10.55003/cast. 2023.06. 23.002 (11 … , 2023 2023 Citations: 13
Development of sustainable polymer-based dielectric composites from agricultural waste: A review KB Mekha, NAT Yusof, K Sudhakar, N Zainol, N Hasan, MSA Karim Heliyon 10 (21) , 2024 2024 Citations: 12
Dielectric material preparation from pineapple leaf fiber based on two-level factorial analysis and its morphological structure MSA Karim, N Zainol, NH Aziz, NSM Hussain, NAT Yusof Journal of Engineering Research 12 (2), 25-33 , 2024 2024 Citations: 12
Fabrication and characterization of epoxy resin–barium titanate at G-band using waveguide technique N Hasan, NSM Hussain, NHSA Razak, ASM Shah, MSA Karim IOP Conference Series: Materials Science and Engineering 1045 (1), 012012 , 2021 2021 Citations: 12
Automatic detection of diabetic retinopathy retinal images using artificial neural network SM Shaharum, NH Hashim, N Abu Talip@ Yusof, MS Abdul Karim, ... Proceedings of the 10th National Technical Seminar on Underwater System … , 2019 2019 Citations: 12