Malaysian Journal of Fundamental and Applied Sciences https://mjfas.utm.my/index.php/mjfas <p><strong>Malaysian Journal of Fundamental and Applied Sciences (MJFAS)</strong><br />Indexed by <strong><a href="https://www.scopus.com/sourceid/21101041523" target="_blank" rel="noopener">Scopus</a></strong>, <a href="https://www.scimagojr.com/journalsearch.php?q=21101041523&amp;tip=sid&amp;clean=0" target="_blank" rel="noopener"><strong>SCImago Journal Rank</strong></a>, <strong><a href="https://mjl.clarivate.com/home?issn=2289-5981&amp;hide_exact_match_fl=true&amp;utm_source=mjl&amp;utm_medium=share-by-link&amp;utm_campaign=search-results-share-this-journal" target="_blank" rel="noopener">Web of Science</a></strong>, and <strong><a href="https://scholar.google.com/citations?user=i1gLaw0AAAAJ&amp;hl=en" target="_blank" rel="noopener">Google Scholar</a></strong></p> <p>Journal abbreviation: <strong>Mal. J. Fund. Appl. Sci.</strong> <br /><strong>ISSN: 2289-5981. e-ISSN: 2289-599X.</strong></p> <p>Editor-in-Chief: <strong><a href="https://hadinur.net/">Hadi Nur</a></strong></p> <p>The Malaysian Journal of Fundamental and Applied Sciences (MJFAS) (formerly known as Journal of Fundamental Sciences (2005-2011), ISSN: 1823-626X) is a refereed research journal managed by <a href="https://ibnusina.utm.my/" target="_blank" rel="noopener">Ibnu Sina Institute for Scientific and Industrial Research (ISI-SIR)</a>, UTM. The aims and scope of the journal encompass research articles, original research reports, reviews, short communications, and scientific commentaries from fundamental principles to practical applications in the broad field of mathematics, physics, chemistry, and biology. All manuscript submissions must be made through the journal's online manuscript system at <a href="https://mjfas.utm.my/index.php/mjfas/about/submissions">Online Submissions</a>. For acceptance in MJFAS, a manuscript must be the right fit with <a href="https://mjfas.utm.my/index.php/mjfas/about">the journal's focus and scope</a>.</p> Penerbit UTM Press en-US Malaysian Journal of Fundamental and Applied Sciences 2289-5981 Lazy Cops and Robber on Certain Cayley Graph https://mjfas.utm.my/index.php/mjfas/article/view/2235 <p>The lazy cop number is the minimum number of cops needed for the cops to have a winning strategy in the game of Cops and Robber where at most one cop may move in any one round. This variant of the game of Cops and Robber, called Lazy Cops and Robber, was introduced by Offner and Ojakian, who provided bounds for the lazy cop number of hypercubes. In this paper, we are interested in the game of Lazy Cops and Robber on a Cayley graph of <em>n</em> copies of Z<sub>m+1</sub>.</p> Kai An Sim Ta Sheng Tan Kok Bin Wong Copyright (c) 2022 Kai An Sim, Ta Sheng Tan, Kok Bin Wong http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 148 156 10.11113/mjfas.v18n2.2235 Extraction rate of Valuable Compounds from Peanut Skin Waste by Ethanol-Assisted Supercritical Carbon Dioxide: Modelling and Optimization https://mjfas.utm.my/index.php/mjfas/article/view/2237 <p>Response Surface Methodology (RSM) was employed to optimize the extraction rate of phenolic and flavonoid contents from peanut skin by supercritical carbon dioxide (ScCO<sub>2</sub>) assisted by ethanol as entrainer. The studied extraction parameters were pressure (10 to 30 MPa), temperature (40 to 70 <sup>o</sup>C), and the ratio of ethanol (2.5 to 7.5%). Brunner’s and Esquivel’s models were applied to evaluate the extraction rate. The best-operating conditions, in the tested range, were 30 MPa, 40 °C, and 4.64% of ethanol ratio, with a maximum extraction rate of 0.22 mg/g.sec and 0.19 mg/g.sec of the phenolic and flavonoid content, respectively. The findings concluded that higher-pressure condition has a significant impact on the extraction rate of phenolic and flavonoid</p> Nicky Rahmana Putra Dwila Nur Rizkiyah Ahmad Hazim Abdul Aziz Zuhaili Idham Lailatul Qomariyah Mohd Azizi Che Yunus Copyright (c) 2022 Nicky Rahmana Putra, Dwila Nur Rizkiyah, Ahmad Hazim Abdul Aziz, Zuhaili Idham, Lailatul Qomariyah, Mohd Azizi Che Yunus http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 157 170 10.11113/mjfas.v18n2.2237 Data Driven Technique for Palm Oil Mills Boiler Water Quality Monitoring in State of Perak Malaysia https://mjfas.utm.my/index.php/mjfas/article/view/2242 <p>Steam boilers are widely used in oil palm mills industries which physically converting the water into steam. Heating water in the boiler allows solid waste such as potassium, calcium, magnesium, silica and ions to stay in the boiler and creates a solid waste layer that coats the tubes and boilers. This strong coating would increase the heating surface of the boiler and decrease the efficiency of heat transfer. This situation will also increase the consumption of fuel, causing the boiler to overheat, which in turn leads to tube failure. The impact of this issue will cause losses to the oil palm plantation due to the shutdown of unplanned plants. Therefore, for this study, Statistical Process Control (SPC) has been utilized to monitor the quality of the 6 parameters of the boiler and boiler feedwater for palm oil mill in Perak State Malaysia to overcome the problem stated above. Boxplot has been utilized to monitor continuously the parameter based on the probability distribution of the data according to ASME guidelines. The findings from this analysis show that some of the palm oil mills is able to maintain their boiler quality accordingly, however, on controlling the silica, hardness and total iron, its need further improvement.</p> M.R. Izham Rusdi T. Bashkeran Z. Ahmad Copyright (c) 2022 M.R. Izham Rusdi, T. Bashkeran, Z. Ahmad http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 171 183 10.11113/mjfas.v18n2.2242 Forecasting Model of Air Pollution Index using Generalized Autoregressive Conditional Heteroskedasticity Family (GARCH) https://mjfas.utm.my/index.php/mjfas/article/view/2279 <p align="justify">The Air Pollution Index (API) of Malaysia has increased consistently in recent decades, becoming a serious environment issue concern. In this paper, we analyzed daily integer value time series data for API in Sarawak from January to June in 2019 using generalized autoregressive conditional heteroskedasticity (GARCH) family for discrete case namely poisson integer value GARCH (INGARCH), negative binomial integer value GARCH (NBINGARCH) and integer value autoregressive conditional heteroskedasticity (INARCH) models. The parameters of the models will be estimated using quasi likelihood estimator (QLE) and we compare their Akaike information criterion (AIC) to determine the best model fitted the data. The results showed that INGARCH (1,1) and INARCH (1,0) performed inconsistent results since the conventional methods of NBINGARCH (1,1) outperformed the performance of INGARCH (1,1) and INARCH (1,0). However, consistet results were achieved as the NBINGARCH (1,1) gave the smallest forecasting error compared to INGARCH (1,1) and INARCH (1,0). The findings are very important for controlling the API results in future and taking protection measure for conservation of the air.</p><p align="justify"> </p> Nurul Asyikin Zamrus Mohd Hirzie Mohd Rodzhan Nurul Najihah Mohamad Copyright (c) 2022 Nurul Asyikin Zamrus, Mohd Hirzie Mohd Rodzhan, Nurul Najihah Mohamad http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 184 196 10.11113/mjfas.v18n2.2279 Empirical correlation of stable double emulsion system of organic compound extraction in emulsion liquid membrane process https://mjfas.utm.my/index.php/mjfas/article/view/2328 <p>The stability of emulsion is crucial in the emulsion liquid membrane (ELM) process. It has been discovered that the size of emulsion droplets and globules is related to ELM stability and can be predicted using a correlation model. In this study, the best correlation for the emulsion size prediction was determined for ELM extraction of succinic acid. Several parameters affecting the emulsion sizes and stability including emulsification speed, emulsification time, agitation speed, and treat ratio were evaluated. A new correlation for the succinic acid system was obtained that fit experimental data between 0.1-0.5 dispersed phased holdup fraction. From the study, the Weber number depended on the emulsification speed, emulsification time, and agitation speed, which consequently affected the predicted emulsion size. This study demonstrates that mathematical correlations can be used to predict the size of emulsion droplets and globules in the ELM process of organic compound extraction.</p> Norela Jusoh Norasikin Othman Leonie Lenta Anak Alfred Ambi Norul Fatiha Mohamed Noah Muhammad Bukhari Rosly Hilmi Abdul Rahman Copyright (c) 2022 Norela Jusoh, Norasikin Othman, Leonie Lenta Anak Alfred Ambi, Norul Fatiha Mohamed Noah, Muhammad Bukhari Rosly, Hilmi Abdul Rahman http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 197 205 10.11113/mjfas.v18n2.2328 Prediction of Zinc Extraction using Facilitated Emulsion Liquid Membrane Model https://mjfas.utm.my/index.php/mjfas/article/view/2329 <p>This study presents the modelling of zinc extraction facilitated by emulsion liquid membrane (ELM). The previously developed model was extended and modified in accordance with the present research objectives and scope. The modified model is based on the chemical interaction between the carrier molecules and zinc ions, as well as the mass transport mechanism. Furthermore, the model also accounts for the effect of Sauter mean diameter on the extraction efficiency. MATLAB was applied to simulate the ELM extraction of zinc based on the validated model. At the optimum conditions, MATLAB simulation produced a similar outcome to the one obtained experimentally. Using the validated model, several parametric studies were conducted, such as the treat ratio, initial zinc concentration, carrier concentration, and stripping agent concentration. The consistent results between the experimental and simulated data increased the reliability of the model as a viable prediction tool for zinc extraction using facilitated ELM.</p> Norul Fatiha Mohamed Noah Norasikin Othman Hakim Binanga Copyright (c) 2022 Norul Fatiha Mohamed Noah, Norasikin Othman, Hakim Binanga http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 206 217 10.11113/mjfas.v18n2.2329 Efficient Synthesis of Novel 1-Substituted β- Carboline Derivatives via Pictet-Spengler Cyclization of 5-Hydroxy-L-Tryptophan https://mjfas.utm.my/index.php/mjfas/article/view/2331 A facile synthesis of novel 1-substituted β-carboline derivatives by using three efficient reaction steps was described. The synthetic route began with the construction of β-carboline frameworks involving the coupling of 5-hydroxy-L-tryptophan with different substituted phenylglyoxal <em>via</em> Pictet-Spengler condensation. Subsequent reduction of carbonyl functionality on carbon-7’ by using Wolff-Kishner reaction followed by N-alkylation afforded a practical access to a series of 1-substituted β-carboline derivatives in moderate yields. These novel derivatives were successfully synthesized without the use of expensive metal catalyst, prolonged reaction hours or critical reaction conditions. The molecular structures of all synthesized derivatives were confirmed by infrared (IR), gas chromatography–mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy. Nur Ain Nabilah Ashari Noor Hidayah Pungot Nor Akmalazura Jani Zurina Shaameri Copyright (c) 2022 Nur Ain Nabilah Ash’ari, Noor Hidayah Pungot, Nor Akmalazura Jani, Zurina Shaameri http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 218 226 10.11113/mjfas.v18n2.2331 General Health of Pregnant Sprague-Dawley Rats and Neonates’ Small Intestine Morphology Upon Maternal Bisphenol A Exposure: A Preliminary Study https://mjfas.utm.my/index.php/mjfas/article/view/2366 <span lang="EN-US">Associations between xenoestrogen bisphenol A (BPA) and multiple types of diseases, including metabolic syndrome, have been recorded in various studies. However, certain subsets of the human population are particularly more vulnerable to BPA repercussions, such as pregnant women, neonates, and children. This study was conducted to investigate the effects of BPA exposure during pregnancy on the general health of mothers and the histopathology of neonates’ small intestines. Eighteen Sprague-Dawley rats were divided into three groups: control, vehicle Tween-80, and 5mg/kg/day BPA after positive mating was confirmed. Physiological parameters consisted of body weight, waist circumference, water, and food intake, and blood pressures were measured at pregnancy day -1 or 2, 7, and 14 to see whether BPA exposure could exert obesogenic impacts on pregnant rats. Newborns were sacrificed to collect blood plasma for BPA analysis and intestinal samples for histopathological examination. Maternal BPA exposure did not affect the physiological parameters of pregnant rats. The number of pups delivered per litter and the sex ratio of BPA offsprings was not significantly different to those of control and vehicle groups (p&gt;0.05). Likewise, the small intestine morphology of BPA neonates was comparable to those of controls and vehicles (preserved structure and absence of inflammatory cells infiltration). The nonsignificant difference in plasma BPA levels of control and BPA-exposed mothers and neonates may explain these findings. Future longitudinal studies which include the dose-dependent impacts of BPA on pregnant mothers’ health and neonates’ small intestine would be more beneficial.</span> Sarah Zulkifli Noor Shafina Mohd Nor Siti Hamimah Sheikh Abdul Kadir Norashikin Mohd Ranai Noor Kaslina Mohd Kornain Zatilfarihiah Rasdi Wan Nor I'zzah Wan Mohamad Zain Amirah Abdul Rahman Jesmine Khan Muhammad Yazid Jalaludin Copyright (c) 2022 Sarah Zulkifli, Noor Shafina Mohd Nor, Siti Hamimah Sheikh Abdul Kadir, Norashikin Mohd Ranai, Noor Kaslina Mohd Kornain, Zatilfarihiah Rasdi, Wan Nor I'zzah Wan Mohamad Zain, Amirah Abdul Rahman, Jesmine Khan, Muhammad Yazid Jalaludin http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 227 236 10.11113/mjfas.v18n2.2366 On Variance Estimation for the Population Size Estimator under One-Inflated Positive Poisson Distribution https://mjfas.utm.my/index.php/mjfas/article/view/2372 <p>Let N<sub>O1PP</sub>be the Horvitz-Thompson estimator for the population size with one-inflated positive Poisson distribution as the underlying distribution. We estimate the variance of this estimator using conditional expectation technique and provide some descriptions on the variance and its associated confidence interval based on simulation study and real data applications.</p> Razik Ridzuan Mohd Tajuddin Noriszura Ismail Kamarulzaman Ibrahim Copyright (c) 2022 Razik Ridzuan Mohd Tajuddin, Noriszura Ismail, Noriszura Ismail, Kamarulzaman Ibrahim, Kamarulzaman Ibrahim http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 237 244 10.11113/mjfas.v18n2.2372 Progressive Freeze Concentration Performance Prediction based on Polynomial Curve Model for Star Fruit Juice Concentration https://mjfas.utm.my/index.php/mjfas/article/view/2386 Progressive freeze concentration (PFC) is a simpler freeze concentration process of removing water content in fruit juice through ice crystal formation in order to concentrate a solution. Vertical finned crystallizer (VFC) was used in the PFC system as the ice crystallizer in this study. A mathematical model is highly needed to be developed so that theories can be validated and to understand the system developed better with minimal risk and cost. Mathematical modelling is also essential to analyze the performance of the system. In this work, the use of mathematical model was explored based on a polynomial regression in analysing and predicting the performance of PFC system. The polynomials curve fitting were first performed to develop the models followed by the simulations to predict the target variables of effective partition constant (K value) and solute recovery (Y value). The relationship of operating parameters including coolant temperature and operation time on the PFC performance values were also discovered via the correlated polynomial regression models. Based on simulations result, the highest efficiencies of PFC process were achieved at approximately - coolant temperature of 10oC and operation time of 55 minutes. To validate the models’ accuracy, the statistical assessment parameters of R-squared and Absolute Average Relative Deviation (AARD) were determined. The findings of this study conferred satisfactory results of the prediction performance of polynomial regression model, in which the least analysis error of AARD (i.e., below 10%) and the highest R-squared (i.e., above 0.97) were successfully achieved. It is concluded that polynomials-based predictive models are promising alternatives to replace time-consuming and expensive experimental evaluation of PFC process for fruit juices. Muhammad Hafizuddin Sofi Noor Hafiza Harun Anis Haryati Mansor Zaki Yamani Zakaria Mazura Jusoh Copyright (c) 2022 Muhammad Hafizuddin Sofi, Noor Hafiza Harun, Anis Haryati Mansor, Zaki Yamani Zakaria, Mazura Jusoh http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 245 256 10.11113/mjfas.v18n2.2386 Free Convection Boundary Layer Flow from a Vertical Truncated Cone in a Hybrid Nanofluid https://mjfas.utm.my/index.php/mjfas/article/view/2410 <p>The present study investigates the mathematical model of free convection boundary layer flow from a vertical truncated cone immersed in <em>Cu/water</em> nanofluid and <em>Al<sub>2</sub>O<sub>3</sub>-Cu/water </em>hybrid nanofluid. The governing non-linear equations are first transformed to a more convenient set of partial differential equations before being solved numerically using the Keller-box method. The numerical values for the reduced Nusselt number and the reduced skin friction coefficient are obtained and illustrated graphically as well as temperature profiles and velocity profiles. Effects of the alumina <em>Al<sub>2</sub>O<sub>3 </sub></em>and copper <em>Cu</em> nanoparticle volume fraction for hybrid nanofluid are analyzed and discussed. It is found that the high-density and highly thermal conductivity nanoparticles like copper contributed more in skin friction and convective heat transfer capabilities. The appropriate nanoparticles combination in hybrid nanofluid may reduce the friction between fluid and surface but yet still gave the heat transfer capabilities comparable to metal nanofluid.</p> Muhammad Khairul Anuar Mohamed Anuar Mohd Ishak Ioan Pop Nurul Farahain Mohammad Siti Khuzaimah Soid Copyright (c) 2022 Muhammad Khairul Anuar Mohamed, Anuar Mohd Ishak, Ioan Pop, Nurul Farahain Mohammad, Siti Khuzaimah Soid http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 257 270 10.11113/mjfas.v18n2.2410 Landslides Susceptibility Mapping in R Program (Case study in Lima Puluh Kota Regency) https://mjfas.utm.my/index.php/mjfas/article/view/2534 <p>Landslide susceptibility zonation is necessary to be considered in land use planning at various scales., different approaches and analytical methods can be used to evaluate and zone the area and processed with GIS software. However, there are constraints in its use, such as the cost of the licenses of software and source code that cannot be accessed and evaluated by users. The recent development of open-source software that can integrate data, analysis, and graphs in a representation such as the R program, has opened up opportunities for researchers to reevaluate and modify interpretation further from available ones to address issues. In this regard, this study aims to create functions in R using the Weight of Evidence (WoE) method, a form of bivariate statistic approach to acquire the significant factors controlling landslides and generate a susceptibility map. The case study is located in Limapuluh Kota Regency, West Sumatra Province of Indonesia, a hilly and mountainous region where its districts are prone to landslides. Eight of eleven factors such as geology, landform, land cover, elevation, density of vegetation greenness, slope, rainfall intensity, and proximity to stream were regarded to control landslides which set up four classes of landslide susceptibility zone (very low, low, moderate, and high).</p> Ahyuni - Ahyuni Bigharta Bekti Susetyo Isra Haryati Diva Zakiyah Mar’ah Hamdi Nur Adenan Yandra Nofrizal Azwirda Aziz Copyright (c) 2022 Ahyunia, Bigharta Bekti Susetyo, Isra Haryati Diva, Zakiyah Mar’ah, Hamdi Nur, Adenan Yandra Nofrizal, Azwirda Aziz http://creativecommons.org/licenses/by-nc/4.0 2022-05-16 2022-05-16 18 2 271 282 10.11113/mjfas.v18n2.2534