National University of Malaysia

About: National University of Malaysia is a education organization based out in Kuala Lumpur, Malaysia. It is known for research contribution in the topics: Population & Heat transfer. The organization has 26593 authors who have published 41270 publications receiving 552683 citations. The organization is also known as: NUM & Universiti Kebangsaan Malaysia.

Review of optimal methods and algorithms for sizing energy storage systems to achieve decarbonization in microgrid applications

Abstract: Carbon emission from the burning of fossil fuel has resulted in global warming Climate change and global warming are among the most complex issues requiring immediate solutions Microgrid (MG) based on renewable energy sources (RESs) can be used to reduce the carbon intensity of electricity and achieve the global decarbonization goal by 2050 Optimizing the size of the energy storage system (ESS) can ensure the sustainable, resilient, and economic operation of the MG Thus, key features of the optimal ESS, including methods and algorithms of ESS sizing, power quality, reliability, connection mode, and public policy enforcement for low-carbon emission, must be identified Existing literature mostly focuses on the cost-effective optimal sizing method based on capacity minimization, which overlooks other issues This work reviews the features of optimal ESS sizing methods and algorithms, their characteristics, and the scenarios between ESS and decarbonization in MG applications to address their shortcomings ESS characteristics on storage type, energy density, efficiency, advantages, and issues are analyzed This review highlights details of ESS sizing to optimize storage capacity, reduce consumption, minimize storage cost, determine the optimal placement and mitigate carbon emission for decarbonization The analyses on the understanding of decarbonization in relation to the use of ESS in MG scenarios are explained rigorously Existing research gaps, issues, and challenges of ESS sizing for next-generation MG development are also highlighted This review will strengthen the efforts of researchers and industrialists to develop an optimally sized ESS for future MGs that can contribute toward achieving the decarbonization goal

Amoxicillin adsorption on microwave prepared activated carbon from arundo donax linn: isotherms, kinetics, and thermodynamics studies

Abstract: Microwave-assisted KOH activation of renewable biomass Arundo donax Linn was adopted for preparation of activated carbon (KAC) with high capacity for amoxicillin antibiotic (AMX). The characteristics of KAC were examined by proximate and pore structure analyses, scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR). The ash and moisture contents of KAC were 5.5 and 0.5% compared to 2.2 and 2.1% for raw biomass. The BET surface area and total pore volume were identified to be 1065.3 m3/g and 0.643 cm2/g, respectively. The best preparation conditions in terms of KAC yield and AMX uptake were reported as 10 min radiation time, 620 W radiation power and 2 g/g impregnation ratio resulted in 9.1% yield and 196.9 mg/g AMX uptake. Experimental equilibrium data for AMX adsorption were analyzed by Langmuir, Freundlich, and Sips isotherms. The results showed that the best fitting was achieved by Sips isotherm with high adsorption capacity of 345.4 mg/g on KAC compared to 75.8 mg/g on precursor. Also, kinetic data were correlated by pseudo-first order, pseudo-second order, and intra-particle diffusion models with well-fitting to pseudo-second order model. Thermodynamic analysis showed that adsorption enthalpy of AMX was 17.7 kJ/mol which revealed endothermic and physisorptive nature under examined conditions.

The fractional-order modeling and synchronization of electrically coupled neuron systems

Abstract: In this paper, we generalize the integer-order cable model of the neuron system into the fractional-order domain, where the long memory dependence of the fractional derivative can be a better fit for the neuron response. Furthermore, the chaotic synchronization with a gap junction of two or multi-coupled-neurons of fractional-order are discussed. The circuit model, fractional-order state equations and the numerical technique are introduced in this paper for individual and multiple coupled neuron systems with different fractional-orders. Various examples are introduced with different fractional orders using the non-standard finite difference scheme together with the Grunwald-Letnikov discretization process which is easily implemented and reliably accurate.