Malaysian Journal of Science 2023-10-31T00:00:00+08:00 Prof. Dr. Wan Haliza binti Abd Majid Open Journal Systems <p style="text-align: justify;">Malaysian Journal of Science (MJS) is the official peer-reviewed open-access journal of the <a href="">Faculty of Science, Universiti Malaya</a>. Effective from the year 2020 onwards, the frequency of regular issues publication is three times a year. MJS is indexed in <a href="">Scopus</a>, <a href=";as_sdt=0%2C5&amp;q=Malaysian+Journal+of+Science&amp;btnG=">Google Scholar</a>, <a href="">Chemical Abstracts Service Database</a>, <a href="">ASEAN Citation Index (ACI)</a>, and <a href="">MYCite</a>.</p> <p style="text-align: justify;">MJS is a reputable journal with a growing audience, which focuses on current developments in all disciplines of science. The journal publishes original articles, review articles, short communications, and case reports that are of importance to the scientific community. </p> <p style="text-align: justify;"><strong>eISSN : 2600-8688<br /></strong><strong><strong>Print ISSN : 1394-3065<br /></strong></strong><strong><strong>Publisher : Faculty of Science, Universiti Malaya</strong></strong> </p> A COMPUTATIONAL DENSITY FUNCTIONAL THEORY INVESTIGATION OF THE INTERACTION OF BORON NITRIDE NANOSHEETS WITH MULTIPLE MOLECULAR HYDROGENS 2022-08-21T21:45:22+08:00 Pek Lan Toh Syed Amir Abbas Shah Naqvi Suh-Miin Wang Yao-Cong Lim Lee-Sin Ang Lan-Ching <p>In this study, the adsorption of molecular hydrogens (H<sub>2</sub>) on boron nitride (BN) frameworks was investigated using the density functional theory (DFT) technique. The results of optimized geometric structures revealed that molecular hydrogens were favourably adsorbed on top of nitrogen atoms in the BN monolayers. In addition, the optimized equilibrium geometries were utilized to calculate the electronic structures, including binding energies, energies of the highest and lowest occupied molecular orbitals (HOMO and LUMO), molecular electrostatic potentials (MEPs), and Mulliken atomic charges (MACs). The binding energy values were calculated to be approximately 0.01 eV per molecular hydrogen based on the results. As the number of molecular hydrogens increased in the BN framework, a slight increase was observed in the binding energy value per hydrogen molecule. Furthermore, the HOMO–LUMO gaps were determined with the corresponding energy values of about 6 eV. Regarding the Frontier molecular orbitals (FMOs) diagrams, the electron densities for the HOMOs of the studied systems were primarily focused on the N-edges. Conversely, for the LUMO, the electron density distribution was localized in the B-edges of titled systems. In the context of hydrogen adsorption on BN nanosheets, the MEP maps indicated that hydrogen atoms at the N-edges of the studied systems exhibited the most positive electrostatic potentials in this research. In contrast, surfaces with negative electrostatic potential surfaces were situated in the region close to B-edges. The computed results are consistent with the corresponding Mulliken atomic charge distributions. From the analyses of the Mulliken scheme, all nitrogen atoms displayed negative charge values, and positive charges were found on the boron atoms. The DFT results obtained in this report may serve as the foundation for developing hydrogen storage materials</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science NUMERICAL SIMULATION OF ENHANCED OPTICAL FREE SPECTRAL RANGE THROUGH INTEGRATED FANO-MICRORING CONFIGURATION 2022-06-21T12:30:55+08:00 Mohammad Amirul Hairol Aman Fakhrurrazi Ahmad Noorden Faris Azim Ahmad Fajri Muhammad Zamzuri Abdul Kadir Wan Hazman Danial Suzairi Daud <p>A numerical analysis of the integrated Fano-microring (IFM) racetrack resonator spectrum was performed to investigate the enhancement of the optical system’s free spectral range (FSR). The FSR is an important optical property which can contribute to the high sensitivity of optical devices. The IFM refers to the combination of Fano resonance produced in the output spectrum through the interaction of Fabry–Perot resonance and circulation resonance. This work focuses on the study of inducing Fano resonance in the microring resonator to optimize the FSR of the system. The results show that the integration of two resonances can produce a Vernier output spectrum, which significantly enhanced the FSR of the system without any need for additional ring waveguides. This work also compared the IFM resonance with the conventional microring resonance. In this simulation, the optimized FSR obtained by the IFM configuration was 266.55 nm, which is five times higher than the conventional microring configuration.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science THE EFFECT OF BALL MILLING ON THE MORPHOLOGY OF CUBIC BORON NITRIDE 2022-10-03T11:21:45+08:00 Shashikala A.R, Aarudi Keerthi Kothakula Ramesh C S Sridhar B S <p>Due to its attractive properties, cubic boron nitride (c-BN) finds extensive applications in mechanical and electronic industries. The conversion of micro c-BN to nano c-BN remarkably influences the properties. This study investigates the effect of ball milling on the morphological parameters. Boron nitride was subjected to different hours of ball milling process at different rotation speeds. The crystallite size of the c-BN was measured at different ball milling time intervals, and we observed that after 100 hours, the crystallite size decreased to nano size. The ball milling was increased to 150-175 hours to get less than 100 nm size particles. The surface morphology and elemental analysis of the samples were done using SEM and EDX studies. EDX confirmed the presence of boron and nitrogen in the sample. SEM images indicated that the agglomerated morphology of c-BN particles had an irregular shape. The cubic structure was confirmed from XRD studies. Thermogravimetric analysis (TGA) conducted to determine the samples' thermal stability indicated that weight loss was observed for temperatures up to 700oC. There was no significant weight loss at a higher temperature. Stronger reflectance was observed with increased ball milling time in UV-Visible DSR studies.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science A SIMPLE 3D TOOLBOX-BASED SMARTPHONE COLORIMETER: THE ABILITY TO DETECT THE STOICHIOMETRIC EQUIVALENT OF A CHEMICAL REACTION 2022-09-26T10:02:36+08:00 Nuntaporn Moonrungsee Jaroon Jakmunee Apaporn Boonmee Juthaporn Kaewloy Waranya Wongkasem Nipat Peamaroon <p>The simple 3D toolbox is constructed and used with a smartphone for detecting the stoichiometric equivalent of chemical reactions. The reaction between salicylic acid and iron(III) ion to form a purple complex is chosen. The captured image of the purple product is measured for RGB color intensities. The color intensities of the solutions depends on concentration of the colored product, and the constant color intensities were observed after the reaction reached its stoichiometry. Several smartphones have been tested for capturing the images and measuring the color intensities. It revealed that all smartphones can be used but the white balance mode is required tuning up to get clear enough picture for color intensity measurement. This smartphone spectrometer provides a comparable results to those obtained from a commercial ultraviolet-visible spectrometer. This work can be a guideline for creation of portable devices in chemical analysis using a smartphone. Moreover, the developed device and method can be practically repeated in chemistry laboratory class for teaching stoichiometry and chemical reaction using a smartphone.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science DEBITTERING OF Borassus flabellifer MESOCARP USING NARINGINASE: IMPACT ON THE COMPOSITION, PHYSICOCHEMICAL CHARACTERISTICS, AND FUNCTIONAL PROPERTIES 2023-02-02T21:21:15+08:00 RODIAH BINTI HASSAN Jamilah Bakar Norhayati Hussain Kharidah Muhamad <p>This study explores the physicochemical, composition, and functional properties of the <em>Borassus flabellifer</em> mesocarp powder following treatment with naringinase. The debittered mesocarp powder (DMP) has good water-holding (9.4 g/g), swelling (7.8 g/g), and wettability (12.3 s) capacities. Naringinase reduced 33.2% of the DMP particle size, causing an increase in surface area. A larger surface area traps more water/oil molecules, contributing to a higher water/oil capacity. However, the solubility, swelling, and wettability of DMP were markedly decreased following naringinase treatment. Nonetheless, although DMP has higher saponin, phenol, tannin, and DPPH activity contents than the control, it has decreased ferrous-reducing activity.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science SYNTHESIS, PHYSICOCHEMICAL ELUCIDATION AND BIOLOGICAL SCREENING STUDY OF NEW LIGAND DERIVED FROM 5,6-O-ISO PROPYLIDENE-L-ASCORBIC ACID AND ITS METAL(II) COMPLEXES 2022-11-08T18:17:18+08:00 Fawzi Al-Hasnawi Lekaa Khalid Abdul Karem Duha Mohammed Mortatha <p>A simple chemistry method approach was used to synthesise new ligand derivate from L-ascorbic acid and its complexes. All of them were water-soluble and are used quite extensively in the medical and pharmaceutical fields. This study synthesised the new ligand derivative from L-ascorbic acid-base using the following steps: A 5,6-O-isopropylidene-L-ascorbic acid was prepared by reacting dry acetone with L-ascorbic acid followed by reacting it with trichloroacetic acid to yield [chloro(carboxylic)methylidene]-5,6-O-isopropylidene-L-ascorbic acid in the second stage. In the third stage, the derivative was reacted with (methyl(6-methyl-2-pyridylmethyl)amine to create a new ligand (ONMILA). This novel ligand was identified using a number of techniques, namely mass spectroscopy, <sup>1</sup>H, <sup>13</sup>C-Nuclear magnetic resonance, Fourier Transform Infrared (FT-IR), and Ultraviolet–visible (UV-Vis) spectra. It was observed that several complexes formed between the ligand and divalent metal ions (Co, Ni, Cu, Zn, Cd). Based on Micro Elemental Analysis, the mole ratio was (1:1) (M:L). Magnetic susceptibility, elemental analysis (C.H.N.O) procedures, molar conductivity tests, and proportion of metal ions calculations were used to describe the complexes. The findings showed the novel ligand had a mono, negative charge and behaved like a tridentate ligand type (N.N.O.). Therefore, the octahedral formula is suggested for all compounds. Only one spot was observed on thin layer chromatography (T.L.C.) for ligand (L) and complexes, indicating that the reaction completed and delivered only a single product. These chemicals have been connected to both Gram-negative and Gram-positive bacteria. The results suggested that antibacterial activity in metal complexes is higher than in the free ligand.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science A NUMERICAL STUDY OF JOULE HEATING EFFECT IN ELECTRODEPOSITION PROCESS-CASE OF COPPER ELECTRODEPOSITION 2022-12-29T12:46:17+08:00 Watheq Hussein Mohammed Ali Alshuraifi Bashar Abid Hamza Raheem Aziz Hussein <p>The electrochemical process in the presence of heat dissipation effect (Joule heating effect) is highly detected in practical electroplating solutions such as 0.6 M CuSO4+0.5 M H<sub>2</sub>SO<sub>4</sub> electrolyte, where currents passing through the cathode-anode-electrolyte increase temperature in the electrolyte and electrodes. Due to the complex nature of such systems and the diversity of physics describing it, a theoretical approach of appearance for natural convection on vertical and horizontal sides of a cathode in the presence and absence of Joule effect under unsteady state condition was observed using Comsol Multiphysics. It was found that the onset of natural convection on a vertical side depends on the Joule effect, and the time (t<sub>n</sub>) for appearance is longer on the edges than in other areas. The horizontal side of a cathode assists the appearance of natural convection in the presence and absence of the Joule effect. The Rayleigh (Ra) number has larger values on the vertical side than the horizontal side due to the effect of surface concentration distribution Cs. A Sherwood, Sh-Ra mathematical relation such that Sh=0.03Ra<sup>0.86 </sup>was proposed where natural convection had no pronounced effect on the deposition process. It was found that the Joule heating effect negatively affects the electrodeposition process by reducing the local current values.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science NEUTRON INDUCED 55Mn REACTION IN THE ENERGY RANGE 0.001 MeV TO 40 MeV 2021-12-13T16:18:02+08:00 A. K. M. Rezaur Rahman Taslim Hoque Happy Mustofa Khalid Ovi Abdul Awal Mark Anthony Bromuela MD. Jubayer Rahman Akhand Shyamal Ranjan Chakraborty A. K. M. Moinul Haque Meaze <p>Neutron induced <sup>55</sup>Mn reactions are evaluated in the energy range 0.001 MeV to 40 MeV using TALYS 1.95 computer code. During this evaluation, local and global parameterisations of Koning and Delaroche are used in nuclear optical model. Comparisons were made with experimental data, collected from EXFOR and other sources. Some optical model parameters (OMP) were needed to be adjusted for better agreement between theoretical calculations and experimental findings. Various evaluated libraries such as ENDF, JENDL etc. are being checked and compared with our evaluation. TALYS evaluation shows better agreement when parameters were adjusted.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science POINT CLOUD SIMPLIFICATION METHOD BASED ON IMPROVED FUZZY C-MEANS WITH AUTOMATIC NUMBER OF CLUSTERS 2022-06-24T14:59:01+08:00 Normi Abdul Hadi Siti Nur Athirah Adibah Maiddin <p>The essence of the point cloud is to express geometric information about objects by getting discrete coordinates on their surfaces. However, with a million points, this data may record redundant details in which it is needless to be kept for the model’s analysis. In addition, there is also a limitation where the processors cannot process the large-size datasets. The point cloud simplification algorithm was developed to solve the stated obstacles in data processing. Numerous algorithms have been published to produce the best methods for data reduction process. Since the simplification process might eliminate essential features of the data, this study introduces the features preservation process to keep the important points before the simplification. This study employed the Fuzzy C-Means (FCM) algorithms for the simplification stage due to their simplicity and ability to generate an accurate result. Regardless, the FCM still suffers from drawbacks, where their initial cluster centres are prone to fall into local optima. This study improved the FCM by employing the Score and Minimum Distance (SMD) to determine the number of clusters and cluster centres. The SMD is enhanced by changing the Gaussian to Cosine kernel function to increase the accuracy. This new technique is named SMD(C)-IFCM. The method was then applied to the 3D point cloud of a box, cup, and Stanford bunny. The performance of the developed method was compared with the original SMD-FCM and SMD-IFCM for the percentage of the simplified data, error evaluation, and processing time. The result and analysis showed that the developed method had the best score, which was six (6) out of nine (9) measurements, compared to the other two methods with scores of one (1) and two (2) respectively. This score suggests that the developed algorithm successfully reduced the error evaluation and the processing time to generate the output.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science QUARTERLY VARIATION OF TROPOSPHERIC SURFACE REFRACTIVITY IN ILORIN, NIGERIA 2022-09-22T21:17:37+08:00 Muhammed Sani Otto Abimbola Johnson Oladiran Falaiye Adeniran Oluwasesan Faisal Usman Muhammad A.A Sule <p>To construct a radio communication system, there is need for extensive knowledge of the refractivity and its variations. This work aims to determine the change in season with tropospheric surface refractivity of Ilorin, Kwara, Nigeria. The refractivity for both dry (1<sup>st</sup> quarter) and rainy (3<sup>rd</sup> quarter) seasons for 2000 - 2002 have been calculated using the meteorological data obtained from the Nigerian Meteorological Agency, Ilorin. The result shows that there is a variation between tropospheric surface refractivity during the dry and rainy seasons. High refractivity during the rainy season than in dry season is observed, mainly due to higher amount of water content in the atmosphere (troposphere) in the rainy season.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science SPATIAL DISTRIBUTION OF MALARIA AND LAND COVER PATTERNS IN OGONI LAND, RIVERS STATE, NIGERIA 2022-10-05T20:46:28+08:00 Sylvia Egbom Florence Onyemachi Nduka Sidney Obidimma Nzeako Chigozie C. Ikechukwu Joseph I. Nwachukwu Chinonye O. Ezenwaka Charity O. Ihejirika Martin C. Opara Emilia O. Anyanwu Blessing O. Agoh Justin N. Okorondu Grace C. Egwuogu <p>The distribution of malaria is characterised by microgeographic variations determined by a range of factors, including the local environment. A study on the spatial distribution of malaria about land cover patterns was carried out by sampling Primary Health Centres in Ogoni Land. Nine Primary Healthcare Centres (PHCs) were selected across four local government areas (LGA) using Systematic Grid Point Sampling. Human blood samples were obtained from 318 consented individuals, and questionnaires were administered to obtain demographic data. <em>Plasmodium </em>species were identified through microscopy using thick and thin blood films. A geodatabase was created and imported into ArcGIS 10.7 to produce a thematic map of the study area. A cloud-free Landsat-8 Operational Land Imager (OLI) was employed for land cover analysis. Both supervised and unsupervised classifications of land cover were performed to generate the land cover classes. Pearson correlation was carried out to determine the significance between malaria distribution and land cover. Of the 318 individuals, 169 were infected with an overall prevalence of 53.1%.Only <em>P. falciparum </em>was identified and malaria distribution showed spatial variations. Across the PHCs sampled, the highest point prevalence was recorded in Model Primary Health Centre Koroma in Tai LGA whereas the lowest was recorded in MPHC Okwale in Khana LGA. Cumulatively, Kwawa PHC recorded the highest malaria prevalence whereas MPHC Bunu in Tai recorded the lowest prevalence. The highest prevalence was recorded in Khana LGA while the lowest was recorded in Eleme LGA. Land cover analysis revealed that Ogoni Land has a total land cover mass of 982.97km.<sup>2 </sup>Sparse vegetation dominated the study area (471.06km<sup>2</sup>) while dense vegetation covers a total mass of 213.1km<sup>2</sup>. Bivariate analysis showed a significant correlation between malaria prevalence and dense vegetation (p&lt;0.05, 0.952). Dense vegetation played a significant role in malaria transmission in Ogoni Land. The study concludes that the presence of dense vegetation is associated with high malaria prevalence in the study area.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science POLYMER-BASED IONIC CONDUCTORS 2023-09-24T22:43:49+08:00 Abdul Kariem Mohd Arof <p>Polymer electrolytes consist of polymer matrices with ion transport capabilities and can exist in either a solid or gel state. In both states, the incorporation of plasticizers and fillers will improve the ionic conductivity. Gel polymer electrolytes (GPEs) exhibit ionic conductivity levels remarkably akin to those of liquid electrolytes, owing to the direct solvation of salts within solid polymer electrolytes.</p> 2023-10-30T00:00:00+08:00 Copyright (c) 2023 Malaysian Journal of Science