M. Al-Saad¹, C. A. Suarez^{2, 4}, A. Obeidat², S. P. A. Bordas^{1, 2, 3, *}, S. Kulasegaram¹

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 831-862, 2020, DOI:10.32604/cmes.2020.08527

Abstract Thrombosis plays a crucial role in atherosclerosis or in haemostasis when a blood vessel is injured. This article focuses on using a meshless particle-based Lagrangian numerical technique, the smoothed particles hydrodynamic (SPH) method, to study the flow behaviour of blood and to explore the flow parameters that induce formation of a thrombus in a blood vessel. Due to its simplicity and effectiveness, the SPH method is employed here to simulate the process of thrombogenesis and to study the effect of various blood flow parameters. In the present SPH simulation, blood is modelled by two sets of particles that have the… More >

Zaiguo Fu^{1, *}, Huanhuan Gao¹, Zhuoxiong Zeng¹, Jiang Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 805-830, 2020, DOI:10.32604/cmes.2020.08825

Abstract In order to comprehensively evaluate the flow and heat transfer performance of a large-size annular combustion chamber of a heavy-duty gas turbine, we carried out numerical computation and analyses on the velocity, temperature and pressure fields in the chamber with double swirlers. The mathematical model of the coupling combustion, gas flow, and heat transfer process was established. The influences of the inlet swirling strength, fuel-air ratio and temperature of the premixed gas on the multi-field characteristics and synergy were investigated on the basis of field synergy theory. The results showed that the central recirculation zone induced by the inlet swirling… More >

Chen Yu¹, Qifu Wang^{1, ∗}, Chao Mei¹, Zhaohui Xia¹

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 779-803, 2020, DOI:10.32604/cmes.2020.09363

Abstract This paper proposes a multiscale isogeometric topology optimization (ITO) method where the configuration and layout of microstructures are optimized simultaneously. At micro scale, a shape deformation method is presented to transform a prototype microstructure (PM) for obtaining a series of graded microstructures (GMs), where microstructural skeleton based on the level set framework is applied to retain more topology features and improve the connectability. For the macro scale calculation, the effective mechanical properties can be estimated by means of the numerical homogenization method. By adopting identical non-uniform rational basis splines (NURBS) as basis functions for both parameterized level set model and… More >

Arka Das¹, Anthony Khoury¹, Eduardo Divo^{1, *}, Victor Huayamave¹, Andres Ceballos², Ron Eaglin², Alain Kassab³, Adam Payne⁴, Vijay Yelundur⁴, Hubert Seigneur⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 757-777, 2020, DOI:10.32604/cmes.2020.08164

Abstract This paper presents a numerical reduced order model framework to simulate the physics of the thermomechanical processes that occur during c-Si photovoltaic (PV) cell fabrication. A response surface based on a radial basis function (RBF) interpolation network trained by a Proper Orthogonal Decomposition (POD) of the solution fields is developed for fast and accurate approximations of thermal loading conditions on PV cells during the fabrication processes. The outcome is a stand-alone computational tool that provides, in real time, the quantitative and qualitative thermomechanical response as a function of user-controlled input parameters for fabrication processes with the precision of 3D finite… More >

Ahmed Abdel-Azeem^1,*, Amr A. Nada^2,3, Anthonia O’Donovan⁴, Vijay Kumar Thakur⁵, Amr Elkelish⁶

Journal of Renewable Materials, Vol.8, No.2, pp. 171-185, 2020, DOI:10.32604/jrm.2020.08960

Abstract There is an increasing interest in developing nanoparticles with diverse biologic activities. To this end, we prepared 10 to 15 nm silver nanoparticles (AgNP) from native isolates of Trichoderma atroviride. Within this study, endophytic fungi hosted four medicinal plants in Saint Katherine Protectorate, South Sinai, Egypt have been isolated by surface sterilization technique on four isolation media. Ten species, based on their frequency of occurrence, out of twenty recovered taxa were tested for their capability to synthesize extracellular AgNPs. Trichoderma atroviride hosted Chiliadenus montanus was found to be the best candidate for the production of mycogenic AgNPs among all examined… More >

Lei Tian, Liuchao Qiu^*, Jingjun Li, Yongsen Yang

Journal of Renewable Materials, Vol.8, No.2, pp. 154-170, 2020, DOI:10.32604/jrm.2020.08701

Abstract In recent decades, the utilization of waste tires, plastic and artificial shale ceramsite as alternative fine aggregate to make self-compacting concrete (SCC) has been recognized as an eco-friendly and sustainable method to manufacture renewable construction materials. In this study, three kinds of recycled aggregates: recycled tire rubber particles, wood-plastic particles, artificial shale ceramsite were used to replace the sand by different volume (5%, 10%, 20% and 30%), and their effects on the fresh and hardened properties of SCC were investigated. The slump flow and V-funnel tests were conducted to evaluate the fresh properties of modified-SCC mixtures. The hardened properties include… More >

Xianglong Lu¹, Tianshui Yu¹, Hailing Wang¹, Ruichun Luo², Pan Liu², Songliu Yuan¹, Lihua Qian^1,*

Journal of Renewable Materials, Vol.8, No.2, pp. 133-151, 2020, DOI:10.32604/jrm.2020.08650

Abstract Hydrogen evolution reaction (HER) in neutral medium suffers from slow kinetics as compared to that in alkaline or acidic conditions, owing to larger Ohmic loss and low proton concentration. Here we report that a self-supported nanoporous Au-SnO_x (NP Au-SnO_x) catalyst with gradient tin oxide surface could significantly enhance HER activity in neutral buffer solution (0.2 M PBS). The NP Au-SnO_x catalyst exhibits a low onset overpotential of 38 mV and a small Tafel slope of 79 mV dec⁻¹ . The current density of 10 mA cm⁻² is manifested at an overpotential as low as 148 mV, representing the comparable performance… More >

Refat Hassan^1,*, Hideo Takagi², Samia Ibrahim³

Journal of Renewable Materials, Vol.8, No.2, pp. 205-218, 2020, DOI:10.32604/jrm.2020.08530

Abstract A spectrophotometric investigation of oxidation of chondroitin-4-sulfate (CS) as a sustainable and biodegradable sulfated macromolecule by oxyanion permanganate ion as multi-equivalent oxidant in acid perchlorate solutions at a constant ionic strength of 2.0 mol dm^-3 has been studied. The experimental results on the influence of the concentration of the reactants the reaction rates revealed first-order dependence in MnO₄^– , fractional second-order in [CS] and fractional first-order with respect to the hydrogen ion concentration. The hydrogen acid concentration dependence of the rate constants indicated that the oxidation rates were increased with increasing the acid concentration which means that the oxidation reaction… More >

Ruyuan Yang¹, Chaokun Hong², Xiaofeng Zhang¹, Quan Yuan³, Youfu Sun^1,*

Journal of Renewable Materials, Vol.8, No.2, pp. 113-132, 2020, DOI:10.32604/jrm.2020.08190

Abstract In order to enhance the bearing capacity of structural components, save materials, and reduce cost, a glued laminated timber (glulam) I-beam that is theoretically suitable for engineering application was proposed. In this study, 18 glulam specimens were fabricated using larch dimension lumber and resorcinol– formaldehyde resin. Four-point bending tests were carried out to compare the ultimate bearing capacity, strain, and deflection of various specimens. The results showed that: (1) The typical failure mode at bending is the web shear failure parallel to grain. Before the failure, cracks and sounds appear at the beam web, which represent the sudden brittle failure.… More >

Brody A. Frost, E. Johan Foster^*

Journal of Renewable Materials, Vol.8, No.2, pp. 187-203, 2020, DOI:10.32604/jrm.2020.07940

Abstract As the world's population exponentially grows, so does the need for the production of food, with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades. This rapid growth in food production results in an ever increasing amount of agricultural wastes, of which already occupies nearly 50% of the total landfill area. For example, is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually. This paper seeks to provide a method for isolating cellulose nanocrystals (CNCs) from spent coffee grounds, in order to recycle and utilize the… More >