Gnaneswara Reddy Machireddy¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 417-442, 2014, DOI:10.3970/fdmp.2014.010.417

Abstract This study deals with the investigation of the effects exerted by heat radiation and a first-order chemical reaction on the magnetohydrodynamics boundary layer slip flow which is established past a vertical permeable surface embedded in a porous medium (with uniform heat and mass flux). The heat equation includes the relevant terms, i.e. the viscous dissipation, radiative heat flux, Ohmic dissipation, and absorption of radiation. The mass transfer equation takes into account the effects related to the chemically reactive species. A classical model for optically thin media is used for studying the effect of radiation. The resulting non-linear coupled partial differential… More >

D. Bothe^1,2, M. Kröger¹, H.-J. Warnecke³

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.3, pp. 303-316, 2011, DOI:10.3970/fdmp.2011.007.303

Abstract In this paper numerical results on reactive mass transfer from single gas bubbles to a surrounding liquid are presented. The underlying numerical method is based on the solution of the incompressible two-phase Navier-Stokes equations. The Volume-of-Fluid method is applied for the description of the liquid-gas interface. Within the numerical approach the concentration of the transfer component is represented by two separate variables, one for each phase. Numerical results are in good agreement with experimental data. More >

A. Pereira¹, P.M.J. Trevelyan², U. Thiele³, S. Kalliadasis¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.4, pp. 303-316, 2007, DOI:10.3970/fdmp.2007.003.303

Abstract We investigate the interaction between thin films and chemical reactions by using two prototype systems: a thin liquid film falling down a planar inclined substrate in the presence of an exothermic chemical reaction and a horizontal thin liquid film with a reactive mixture of insoluble surfactants on its surface. In the first case the chemical reaction has a stabilizing influence on the dynamics of the film and dampens the free-surface solitary pulses. In the second case the chemical reaction can destabilize the film and lead to the formation of free-surface solitary pulses. More >

P. Yu¹, T. S. Lee¹, Y. Zeng¹, H. T. Low²

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.3, pp. 235-246, 2005, DOI:10.3970/fdmp.2005.001.235

Abstract A numerical model is developed for the investigation of flow field and mass transport in a micro-bioreactor, of working volume below 5 ml, in which medium mixing is generated by a magnetic stirrer-rod rotating on the bottom. The flow-field results show that a recirculation region exists above the stirrer rod and rotates with it; the related fluid mixing is characterized by a circulation coefficient of up to 0.2 which is about five times smaller than that of a one-litre stirred-tank bioreactor. The oxygen transfer coefficient is less than 5 h^-1 which is two orders smaller than that of a 10-litre… More >

Tiejun Wang¹, Tao Wu^1,*, Amir Homayoon Ashrafzadeh², Jia He¹

CMC-Computers, Materials & Continua, Vol.57, No.1, pp. 81-96, 2018, DOI:10.32604/cmc.2018.03259

Abstract Crowdsourcing is widely used in various fields to collect goods and services from large participants. Evaluating teaching quality by collecting feedback from experts or students after class is not only delayed but also not accurate. In this paper, we present a crowdsourcing-based framework to evaluate teaching quality in the classroom using a weighted average operator to aggregate information from students’ questionnaires described by linguistic 2-tuple terms. Then we define crowd grade based on similarity degree to distinguish contribution from different students and minimize the abnormal students’ impact on the evaluation. The crowd grade would be updated at the end of… More >

Kabir Fardad¹, Bahman Najafi¹, Sina Faizollahzadeh Ardabili¹, Amir Mosavi^2,3, Shahaboddin Shamshirband,^4,5,*, Timon Rabczuk²

CMC-Computers, Materials & Continua, Vol.55, No.3, pp. 381-392, 2018, DOI: 10.3970/cmc.2018.01803

Abstract Glycyrrhiza glabra, Mint, Cuminum cyminum, Lavender and Arctium medicinal are considered as edible plants with therapeutic properties and as medicinal plants in Iran. After extraction process of medicinal plants, residual wastes are not suitable for animal feed and are considered as waste and as an environmental threat. At present there is no proper management of waste of these plants and they are burned or buried. The present study discusses the possibility of biogas production from Glycyrrhiza Glabra Waste (GGW), Mentha Waste (MW), Cuminum Cyminum Waste (CCW), Lavender Waste (LW) and Arctium Waste (AW). 250 g of these plants with TS… More >

Xian Tang^1,*, Ziyang Chen², Haiyan Zhang³, Xiang Liu¹, Yunyu Shi¹, Asad Shahzadi⁴

CMC-Computers, Materials & Continua, Vol.55, No.2, pp. 267-283, 2018, DOI:10.3970/cmc.2018.01839

Abstract Answering reachability queries is one of the fundamental graph operations. Existing approaches either accelerate index construction by constructing an index that covers only partial reachability relationship, which may result in performing cost traversing operation when answering a query; or accelerate query answering by constructing an index covering the complete reachability relationship, which may be inefficient due to comparing the complete node labels. We propose a novel labeling scheme, which covers the complete reachability relationship, to accelerate reachability queries processing. The idea is to decompose the given directed acyclic graph (DAG) G into two subgraphs, G1 and G2. For G1, we… More >

Liang Yang^1,2, Caizhuang Wang^3,*, Shiwei Lin^2,*, Yang Cao², Xiaoheng Liu¹

CMC-Computers, Materials & Continua, Vol.55, No.1, pp. 177-188, 2018, DOI:10.3970/cmc.2018.055.177

Abstract Understanding of metal oxidation is very critical to corrosion control, catalysis synthesis, and advanced materials engineering. Metal oxidation is a very complex phenomenon, with many different processes which are coupled and involved from the onset of reaction. In this work, the initial stage of oxidation on titanium surface was investigated in atomic scale by molecular dynamics (MD) simulations using a reactive force field (ReaxFF). We show that oxygen transport is the dominant process during the initial oxidation. Our simulation also demonstrate that a compressive stress was generated in the oxide layer which blocked the oxygen transport perpendicular to the Titanium… More >

G. Smith¹, E. Schlangen², P.E.J. Flewitt³, A.G. Crocker⁴, A. Hodgkins⁵

CMC-Computers, Materials & Continua, Vol.51, No.3, pp. 163-185, 2016, DOI:10.3970/cmc.2016.051.163

Abstract Two linked models have been developed to explore the relationship between the amount of porosity arising in service from both radiolytic oxidation and fast neutron damage that influences both the strength and the force-displacement (load-displacement) behaviour and crack propagation in pile grade A graphite used as a nuclear reactor moderator material. Firstly models of the microstructure of the porous graphite for both unirradiated and irradiated graphite are created. These form the input for the second stage, simulating fracture in lattice-type finite element models, which predicts force (load)-displacement and crack propagation paths. Microstructures comprising aligned filler particles, typical of needle coke,… More >