International Journal of Engineering, Science and Technology <p><em>International Journal of Engineering, Science and Technology</em> (IJEST) - an E-journal is an international peer-reviewed, electronic, online journal published by MultiCraft. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of engineering, science and technology. IJEST publishes articles that emphasizes research, development and application within the fields of engineering, science and technology. Original theoretical work and application-based studies, which contributes to a better understanding of engineering, science and technological challenges, are encouraged. All manuscripts are pre-reviewed by the editor, and if appropriate, sent for blind peer review. Contributions must be original, not previously or simultaneously published elsewhere, and are critically reviewed before they are published. Papers, which must be written in English, should have sound grammar and proper terminologies.</p><p>Papers are published in IJEST based on the outcomes of the peer-review processes and no article processing fees or publication fees are charged; it is free to publish in IJEST.</p><p>Other sites related to this journal: <a title="" href="" target="_blank"><cite class="gmail-iUh30"></cite></a></p> en-US Copyright belongs to the journal (S. A. Oke, PhD) (R.M. Jingura, PhD) Fri, 09 Jul 2021 15:02:57 +0000 OJS 60 Incentive-based demand response in grid-connected microgrid using quasi-opposed grey wolf optimizer <p>The paradigm shifts in the electrical industry from demand-driven generation to supply-driven generation due to the incorporation of renewable generating sources is a growing research field. Implementing demand response in present-day distribution schemes is anattractive approach often adopted by microgrid (MiG) operator.This paper incorporates an incentivebased demand response (IBDR) method in a grid-connected microgrid (MiG) comprising of conventional generators (CGs), wind turbines (WTs), and solar PV units. The main aim is to collectively minimize the fossil fuel cost of CGs, lower the transaction cost of portable power from the grid, and maximize theMiG operator's profitafter implementing demand response. This multi-objective problem combining optimal economic load dispatch of MiG with an efficient demand-side response is solved using a proposed Quasi-opposed Grey Wolf Optimizer (QOGWO) algorithm. The effect of the proposed algorithm on demand-side management (DSM) is analyzed for two cases, (i) varying the value of power&nbsp; interruptibility (ii) varying the maximum limit of curtained power. Performance of QOGWO is compared with original GWO and a variant of GWO, Intelligent Grey Wolf Optimizer (IGWO). Results show the superior global search capability and complex constrained handling&nbsp; capability of QOGWO.</p> <p>&nbsp;</p> Salil Madhav Dubey, Hari Mohan Dubey, Manjaree Pandit Copyright (c) Fri, 09 Jul 2021 00:00:00 +0000 Physicochemical characterization of biochars from <i>Eucalyptus maiden Entandrophragma cylindricum</i> (Liboyo), <i>Milicia excelsa</i> (Muvula.) and <i>Ocotea michelsonie</i> (licheche) used in Goma city, DR Congo for water treatment potentials <p>In recent years, research on biochar as an eco-friendly material and cost-effective means for water treatment, soil amendment and carbon sequestration has gained more attention due to the availability of feedstock, the simplicity of the preparation methods, and their enhanced physico-chemical properties. Given that pyrolysis temperature and resident time amongst other factors have significant effect on biochar’s pollutant removal efficacy, this study focused on the evaluation of some properties of biochars produced by pyrolysis (500 - 600 °C) from <em>Entandrophragma cylindricum</em> (ECB), <em>Eucalyptus maiden</em> (EMB), <em>Milicia excelsa</em> (MEB) and <em>Ocotea michelsonie</em> (OMB) sawdusts for their water treatment potentials by using standardized methods. Biomass generated from wood mill in the city of Goma (DR Congo) is valorised for the first time as potential water&nbsp; purifier. The highest yield was obtained from OMB (36.6%) which was found to be significantly greater that those of ECB and EMB (p&lt;0.05). All the biochars had neutral to weakly alkaline pH (7.10-7.90), very high porosity (92-94%, with EMB having the highest value) and ash content between 9.40 and 18.40%, with the highest value attributed to OMB). Most physical and chemical characteristics of biochars varied significantly due to different wood species. Potential toxic elements were far below<br>environmental threshold values and exchangeable cations were equally detected in the biochars. The obtained biochars are therefore seen as good media for water treatment. </p> Amboko Benjamin Muhiwa, Mathias Fru Fonteh, Estella Buleng Tamungang Njoyim, François N. Gapgue Copyright (c) Fri, 09 Jul 2021 00:00:00 +0000 Design and development of an automatic kilcha (skeining) machine <p>Denier test for raw silk testing requires skeins of 450 metres length in slightly twisted form (Kilcha), and the existing process<br>is done manually with skein winder, that has few drawbacks, which are low production, quality and higher time and labour.<br>Hence, the present study proposed to design and develop a machine to rectify the above drawbacks for faster production with<br>good-quality silk skeins, and to reduce testing time and labours involved in work. The innovated machine is designed and<br>developed as automatic skeining (Kilcha) machine and the result showed improvement in production, and quality with reduction<br>in time and labour compared to the manual winder.<br><br></p> D. Sargunamani, K. Raghu, Subhas V. Naik Copyright (c) Fri, 09 Jul 2021 00:00:00 +0000 Erosive investigation of various erosion models for vibro cleaner developed based on ultrasonic technique using COMSOL multiphysics <p>The ability of ultrasound to produce highly controlled erosion phenomenon was investigated and various erosion models have been compared by considering various parameters. In cleaning industry, Vibro Cleaner (VC) has been used to remove contaminations from the surface of metal components. This process is most preferable to out of reach or critical surface of the objects. The novelty of this research is to compare various erosion models and to identify appropriate model for ultrasonic cleaning application to get meaningful results of metal removal rate. The computational model of Vibro Cleaner has been developed using pressure acoustic transient in COMSOL Multiphysics software. Acoustic and Computational Fluid Dynamics (CFD) modules have been coupled together to investigate erosion rate. In acoustic approach, acoustic pressure and sound pressure level have been studied by means of piezoelectric transducer through tank wall transience. In CFD approach, Bubbly fluid flow has been applied to get turbulence in acoustic streaming. Also, particle tracing has been coupled to understand the particle trajectories and motion of fluid flow. Erosion terms are also introduced at a surface of metal parts which need to be clean. The Erosion rate has been evaluated by using cavitation erosion phenomenon in which cavitation bubbles strike and implode over the metal surface and clean the dirt, dust, oil and other contaminations. Various Erosion models like Finnie, E/CRC, Oka and Det Norske Veritas (DNV) have been studied and results have been compared to identify appropriate erosion model towards the ultrasonic cleaning application by considering 28 kHz frequency and PZT-4 piezoelectric transducer. Comparative study leads to conclude that the Finnie erosion model have given stringent results as compare to other erosion model.</p> <p>&nbsp;</p> Vipulkumar Rokad, Divyang H. Pandya Copyright (c) Fri, 09 Jul 2021 00:00:00 +0000 Modeling the dynamics of a real biological system <p>Infectious cells are and will continue to be a global problem, regarding the alteration of the health of individuals, the motivation for choosing this topic being the major implication the infectious cells has within the public health system and the way it acts, managing to successfully overcome barriers which the body raises to maintain cellular stability. The article brings new contributions related to the topic of dynamic modeling the immunity system, by determining a mathematical model of the interaction between the cells of the immune system and the cells of the infectious agent. Different types of behaviors are presented taking into account the entry of viral particles into the target cells, behaviors of the model without delay time, followed by time predictions for the delay time model. Finally, we compared the models and concluded that the delay time model is much more realistic, through the oscillations and fluctuations in the three components in the primary stages of infection.</p> <p>&nbsp;</p> I.O. Lixandru-Petre Copyright (c) Fri, 09 Jul 2021 00:00:00 +0000 Comparison of the supervised machine learning techniques using WPT for the fault diagnosis of cylindrical roller bearing <p>In this paper, a comparative study of the Artificial Intelligence (AI) techniques for the condition monitoring of the cylindrical roller bearing is presented. For the feature selection, wavelet analysis is applied using the ‘sym2’ as the mother wavelet. Nine features are considered for the training and evaluation of the AI techniques and then effectiveness is compared. Bearing sample data consists of four different conditions as having defective inner race, defective outer race, having defects on roller and a healthy bearing. For the preparation of the sample bearing, laser machine is used for introduction of the micro size defects on the surfaces. Support Vector Machine (SVM), Artificial neural network (ANN), and logistic regression are used with feature ranking method for the data training purpose and their effectiveness of identifying the condition is the major purpose. Feature ranking method is the new way of filtering the right data in right sequence for the data training. In results, Logistic regression found more accurate in comparison with the ANN and SVM for the cylindrical bearing.<br><br></p> Umang Parmar, D.H. Pandya Copyright (c) Fri, 09 Jul 2021 00:00:00 +0000 Parameter uniform numerical methods for singularly perturbed delay parabolic differential equations with non-local boundary condition <p>The motive of this paper is, to develop accurate and parameter uniform numerical method for solving singularly perturbed delay parabolic differential equation with non-local boundary condition exhibiting parabolic boundary layers. Also, the delay term that occurs in the space variable gives rise to interior layer. Fitted operator finite difference method on uniform mesh that uses the procedures of method of line for spatial discretization and backward Euler method for the resulting system of initial value problems in temporal direction is considered. To treat the non-local boundary condition, Simpsons rule is applied. The stability and parameter uniform convergence for the proposed method are proved. To validate the applicability of the scheme, numerical examples are presented and solved for different values of the perturbation parameter. The method is shown to be accurate of O(h<sup>2</sup> + △t) . Finally, conclusion of the work is included at the end.<br><br></p> Wakjira Tolassa Gobena, Gemechis File Duressa Copyright (c) Fri, 09 Jul 2021 00:00:00 +0000