Browsing by Author "Begum, Feroza"

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Characteristics of Ultrasensitive Hexagonal-Cored Photonic Crystal Fiber for Hazardous Chemical Sensing
(MDPI, 2022-01-10) Maidi, Abdul; Shamsuddin, Norazanita; Wong, Wei-Ru; Kaijage, Shubi; Begum, Feroza
A highly sensitive non-complex cored photonic crystal fiber sensor for hazardous chemical sensing with water, ethanol, and benzene analytes has been proposed and is numerically analyzed using a full-vector finite element method. The proposed fiber consists of a hexagonal core hole and two cladding air hole rings, operating in the lower operating wavelength of 0.8 to 2.6 μm. It has been shown that the structure has high relative sensitivity of 94.47% for water, 96.32% for ethanol and 99.63% for benzene, and low confinement losses of 7.31 × 10−9 dB/m for water, 3.70 × 10−10 dB/m ethanol and 1.76 × 10−13 dB/m benzene. It also displays a high power fraction and almost flattened chromatic dispersion. The results demonstrate the applicability of the proposed fiber design for chemical sensing applications.
Design and Simulation of Photonic Crystal Fiber for Liquid Sensing
(MDPI, 2021-01-12) Maidi, Abdul; Yakasai, Izaddeen; Abas, Emeroylariffion; Nauman, Malik; Apong, Rosyzie; Kaijage, Shubi; Begum, Feroza
A simple hexagonal lattice photonic crystal fiber model with liquid-infiltrated core for different liquids: water, ethanol and benzene, has been proposed. In the proposed structure, three air hole rings are present in the cladding and three equal sized air holes are present in the core. Numerical investigation of the proposed fiber has been performed using full vector finite element method with anisotropic perfectly match layers, to show that the proposed simple structure exhibits high relative sensitivity, high power fraction, relatively high birefringence, low chromatic dispersion, low confinement loss, small effective area, and high nonlinear coefficient. All these properties have been numerically investigated at a wider wavelength regime 0.6–1.8 μm within mostly the IR region. Relative sensitivities of water, ethanol and benzene are obtained at 62.60%, 65.34% and 74.50%, respectively, and the nonlinear coefficients are 69.4 W−1 km−1 for water, 73.8 W−1 km−1 for ethanol and 95.4 W−1 km−1 for benzene, at 1.3 μm operating wavelength. The simple structure can be easily fabricated for practical use, and assessment of its multiple waveguide properties has justified its usage in real liquid detection.
Highly sensitive biosensor based on a microstructured photonic crystal fibre for alcohol sensing
(Elseiver, 2023-04-15) Ang, Chuan; Maid, Abdul; Kaijage, Shubi; Begum, Feroza
A microstructure alcohol biosensor has been proposed to operate in the wavelength range of 0.8 to 2.0 μm for the sensing of propanol, butanol, and pentanol, unveiling impressive results of relative sensitivity and confinement loss. The results are achieved by implementing closely arranged cladding air holes of 3 rings with a single elliptical core hole for analyte infiltration. Performance evaluation of the sensor was conducted using COMSOL Multiphysics software and yields relative sensitivity of 96.75%, 89.60%, and 82.02% for propanol, butanol, and pentanol, respectively, and confinement losses of 5.49 × 10 12 dB/m for propanol, 1.98 × 10 12 dB/m for butanol, and 9.36 × 10 13 dB/m for pentanol. Other optical parameters have also been analysed that recorded effective refractive index, high power fraction, low birefringence, small effective area, and large nonlinear co- efficients. The proposed biosensor is eligible for practical application in alcohol sensing with these results. Moreover, this proposed biosensor is suitable as a supercontinuum source in optical communication systems because of the high nonlinear coefficients.
Lifetime improved WSN using enhanced-LEACH and angle sector-based energy-aware TDMA scheduling
(Cogent Engineering, 2020-07-20) Sinde, Ramadhani; Begum, Feroza; Njau, Karoli; Kaijage, Shubi
Network lifetime remains as a significant requirement in Wireless Sensor Network (WSN) exploited to prolong network processing. Deployment of low power sensor nodes in WSN is essential to utilize the energy efficiently. Clustering and sleep scheduling are the two major processes involved in improving network lifetime. However, abrupt and energy unaware selection of cluster head (CH) is nonoptimal in WSN which reflects in the drop of energy among sensor nodes. This paper addresses the twofold as utilization of sensor nodes to prolong the node’s energy and network lifetime by LEACH-based cluster formation and Time Division Multiple Access scheduling (TDMA). Clusters are constructed by the design of an EnhancedLow-Energy adaptive Clustering Hierarchy protocol (E-LEACH) that uses parallel operating optimization (Grey Wolf Optimization (GWO) and Discrete Particle Swarm Optimization (D-PSO)) for selecting an optimal CH and helper CH. The fitness values estimation from GWO and D-PSO is concatenated to prefer the best optimal CH. E-LEACH also manages the cluster size which is one of the conventional disadvantages in LEACH. CHs are responsible to perform energy-aware TDMA scheduling which segregates the coverage area into 24 sectors. Alternate sectors are assigned
Modelling and simulation of novel liquid-infiltrated PCF biosensor in Terahertzfrequencies
(IET Optoelectronics, 2020-07-23) Suhaimi, Nurul; Yakasai, Izaddeen; Abas, Emeroylariffion; Kaijage, Shubi; Begum, Feroza
The liquid-infiltrated photonic crystal fibre (LI-PCF) is proposed for guiding terahertz radiation. Geometricalasymmetry is achieved by introducing a large ellipse in the core. By filling the ellipse with liquid cocaine, the optical properties ofthe photonic crystal fibre (PCF) are theoretically examined using finite element method-based COMSOL multiphysics software.At an operating frequency of 1 THz, the proposed LI-PCF demonstrates a sensitivity of 87.02% and confinement loss in theorder of 10−4 cm−1. The PCF also demonstrates extremely low effective material loss <0.01 cm−1, a birefringence of 0.018, largeeffective mode area of 1.11 × 105 μm2, a high numerical aperture of 0.45 and near-zero ultra-flattened chromatic dispersion of1.4351 ± 0.5883 ps/THz/cm. The design simplicity and high sensitivity, strong confinement factor, low material losses and highbirefringence of the fibre suggest that the proposed fibre may be convenient for PCF-based cocaine sensing, for application inthe security and defence industries
Proposal for a Quad-Elliptical Photonic Crystal Fiber for Terahertz Wave Guidance and Sensing Chemical Warfare Liquids
(MDPI, 2019-07-08) Yakasai, Izaddeen; Abas, Emeroylariffion; Kaijage, Shubi; Caesarendra, Wahyu; Begum, Feroza
A porous-core photonic crystal fiber based on a cyclic olefin homopolymer (Zeonex) is proposed; it shows high birefringence, high core power fraction, low losses, and near-zero flat dispersion. The fiber’s core was designed with quad-elliptical (QE) air holes with its center occupied by bulk background material. The superiority of the QE design over the commonly adopted tri- and penta-elliptical (TE and PE) core designs is demonstrated. The presence of the bulk material at the core center and the geometrical configuration cause a broad contrast in phase refractive indices, thereby producing high birefringence and low transmission losses. A high birefringence of 0.096 was obtained at 1.2 THz, corresponding to a total loss of 0.027 cm−1 and core power fraction of approximately 51%. The chromatic dispersion and effective area of the reported fiber were also characterized within a frequency range of 0.4–1.6 THz. The QE air holes were then filled with chemical warfare agents, namely, tabun and sarin liquids. Then, the relative sensitivity, confinement loss, fractional power flow, and effective material loss (EML) of the sensor were calculated. Nearly the same relative sensitivity (r = 64%) was obtained when the QE core was filled with either liquid. Although the obtained EML for tabun was 0.033 cm−1 and that for sarin was 0.028 cm−1, the confinement loss of the fiber when it was immersed in either liquid was negligible. The proposed fiber can be fabricated using existing fabrication technologies. Moreover, it can be applied and utilized as a THz radiation conveyor in a terahertz time domain spectroscopy system for remote sensing of chemical liquids in the security and defense industries.
Refining Network Lifetime of Wireless Sensor Network Using Energy-Efficient Clustering and DRL-Based Sleep Scheduling.
(MDPI, 2020-03-10) Sinde, Ramadhani; Begum, Feroza; Njau, Karoli; Kaijage, Shubi
Over the recent era, Wireless Sensor Network (WSN) has attracted much attention among industrialists and researchers owing to its contribution to numerous applications including military, environmental monitoring and so on. However, reducing the network delay and improving the network lifetime are always big issues in the domain of WSN. To resolve these downsides, we propose an Energy-Efficient Scheduling using the Deep Reinforcement Learning (DRL) (ES-DRL) algorithm in WSN. ES-DRL contributes three phases to prolong network lifetime and to reduce network delay that is: the clustering phase, duty-cycling phase and routing phase. ES-DRL starts with the clustering phase where we reduce the energy consumption incurred during data aggregation. It is achieved through the Zone-based Clustering (ZbC) scheme. In the ZbC scheme, hybrid Particle Swarm Optimization (PSO) and Affinity Propagation (AP) algorithms are utilized. Duty cycling is adopted in the second phase by executing the DRL algorithm, from which, ES-DRL reduces the energy consumption of individual sensor nodes effectually. The transmission delay is mitigated in the third (routing) phase using Ant Colony Optimization (ACO) and the Firefly Algorithm (FFA). Our work is modeled in Network Simulator 3.26 (NS3). The results are valuable in provisions of upcoming metrics including network lifetime, energy consumption, throughput and delay. From this evaluation, it is proved that our ES-DRL reduces energy consumption, reduces delays by up to 40% and enhances throughput and network lifetime up to 35% compared to the existing cTDMA, DRA, LDC and iABC methods.