Hao Cheng, Guangsheng Du^*, Meng Zhang, Kun Wang, Wenbin Bai

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.4, pp. 685-698, 2020, DOI:10.32604/fdmp.2020.09673

Abstract The determination of the circulation for wind turbine blades is an important problem in engineering. In the present study, we develop a specific approach to evaluate the integral that represents mathematically the circulation. First the potentialities of the method are assessed using a two-dimensional NACA64_A17 airfoil as a testbed and evaluating the influence of different integration paths and angles of attack on the circulation value. Then the method is applied to blades with different relative heights in order to provide useful reference data to be used for the optimization and reverse design of wind turbine blades. As shown by the… More >

Rui Chen^{1, 2}, Yong Wang^{1, 2}, Ruitao Peng^{1, 2, *}, Shengqiang Jiang^{1, 2}, Congfang Hu^{1, 2}, Ziheng Zhao^{1, 2}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 717-737, 2020, DOI:10.32604/cmes.2020.07438

Abstract An inverse method for parameters identification of discrete element model combined with experiment is proposed. The inverse problem of parameter identification is transmitted to solve an optimization problem by minimizing the distance between the numerical calculations and experiment responses. In this method, the discrete element method is employed as numerical calculator for the forward problem. Then, the orthogonal experiment design with range analysis was used to carry out parameters sensitivity analysis. In addition, to improve the computational efficiency, the approximate model technique is used to replace the actual computational model. The intergeneration projection genetic algorithm (IP-GA) is employed as the… More >

M. J. Huntul¹, D. Lesnic^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 475-494, 2020, DOI:10.32604/cmes.2020.08791

Abstract In this paper, we consider solving numerically for the first time inverse problems of determining the time-dependent thermal diffusivity coefficient for a weakly degenerate heat equation, which vanishes at the initial moment of time, and/or the convection coefficient along with the temperature for a one-dimensional parabolic equation, from some additional information about the process (the so-called over-determination conditions). Although uniquely solvable these inverse problems are still ill-posed since small changes in the input data can result in enormous changes in the output solution. The finite difference method with the Crank-Nicolson scheme combined with the nonlinear Tikhonov regularization are employed. The… More >

Lionel Fabian Fourie¹, Lynndle Square^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 225-235, 2020, DOI:10.32604/fdmp.2020.08771

Abstract A heat transfer study was conducted, in the framework of Computational Fluid Dynamics (CFD), on a Hot-Wire Chemical Vapour Deposition (HWCVD) reactor chamber to determine a safe deposition distance for atomic hydrogen produced by HWCVD. The objective of this study was to show the feasibility of using heat transfer simulations in determining a safe deposition distance for deposition of this kind. All CFD simulations were set-up and solved within the framework of the CFD packages of OpenFOAM namely; snappyHexMesh for mesh generation, buoyantSimpleFoam and rhoSimpleFoam as the solvers and paraView as the post-processing tool. Using a standard set of deposition… More >

Baichun Gong¹, Shuang Li^{1, *}, Lili Zheng², Jinglang Feng³

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 221-234, 2020, DOI:10.32604/cmes.2020.07769

Abstract A closed-form solution to the angles-only initial relative orbit determination (IROD) problem for space rendezvous with non-cooperated target is developed, where a method of hybrid dynamics with the concept of virtual formation is introduced to analytically solve the problem. Emphasis is placed on developing the solution based on hybrid dynamics (i.e., Clohessy-Wiltshire equations and two-body dynamics), obtaining formation geometries that produce relative orbit state observability, and deriving the approximate analytic error covariance for the IROD solution. A standard Monte Carlo simulation system based on two-body dynamics is used to verify the feasibility and evaluate the performance proposed algorithms. The sensitivity… More >

Hui ZHAO^1,2, Fan ZHANG^1*, Ling LI¹, Pingang HE¹, Yuzhi FANG¹

BIOCELL, Vol.37, No.3, pp. 77-83, 2013, DOI:10.32604/biocell.2013.37.077

Abstract The human neuroblastoma SH-SY5Y cell line has been used as a model to study mechanisms of neurotransmitter release. In order to study the mechanism of SH-SY5Y single cell exocytosis stimulated by different stimulants, including high K+, 3-(1-nitroso-2-pyrrolidinyl) pyridine and nicotine, a type of indium tin oxide (ITO) micro-pore electrode was used to obtain the corresponding amperometric response time. When the cell is stimulated by 0.1 M K+ , almost immediate exocytosis could be detected, due to the rapid depolarization of cell membrane. However, the stimulations with 1 mM nicotine and 3-(1-nitroso-2-pyrrolidinyl) pyridine result in a short delay between stimulation and… More >

LETTY MARCANO, INGRID CARRUYO, YUSMARY FERNÁNDEZ, XIOMARA MONTIEL, ZAIDA TORREALBA.

BIOCELL, Vol.30, No.2, pp. 259-267, 2006, DOI:10.32604/biocell.2006.30.259

Abstract The vanadium is a metal that presents great interest from the toxicological point of view, because of the numerous alterations that can take place in different biological systems. This work evaluated the capacity of vanadium accumulation and its correlation with genotoxic effects in root cells of Allium cepa L. The bulbs were cultivated in renovated filtered water each 24 h, at a temperature of 25 ± 0.5°C, in darkness and constant aeration. Treatments were carried out under the same experimental conditions, using water solutions of vanadium of 25, 50, 75 and 100μg/g for 0, 12, 24, 48 and 72 h.… More >

Cerna E, Y Ochoa, LA Aguirre, M Flores, J Landeros

Phyton-International Journal of Experimental Botany, Vol.82, pp. 63-68, 2013, DOI:10.32604/phyton.2013.82.063

Abstract Southeastern potato growing regions from Coahuila and Nuevo León contribute with 15% to domestic production. Such production has been impacted by several factors, in particular Bactericera (=Paratrioza) cockerelli Sulc potato psyllid, one of the most important pests affecting this crop. Its control is based on Insecticide applications, leading to unsatisfactory results and high selection pressure. Five insecticides were evaluated in four field populations of B. cockerelli from the growing region, using a susceptible laboratory line for comparison. The field populations were collected from greenhouse and commercial orchards located at Huachichil, Saltillo, Raíces and San Rafael localities. All the samples were… More >

G. Olmi¹

Structural Durability & Health Monitoring, Vol.8, No.1, pp. 61-90, 2012, DOI:10.3970/sdhm.2012.008.061

Abstract Turbogenerator rotors and coil retaining rings are highly loaded components, under low cycle fatigue at every machine switch on and switch off transient. Their failure during service may lead to very serious consequences. The present paper utilizes several experimental data, concerning the static, cyclic and fatigue behaviour of the rotor material, in order to perform a probabilistic analysis. All the main methodological issues are tackled, consisting in the experimental data processing, in the choice of the random variables that are involved in the fatigue process, in the determination of their distributions, in the practical computation of the probability of failure… More >

P. Ramamurty Raju¹, B. Satyanarayana², K. Ramji³

Structural Durability & Health Monitoring, Vol.4, No.3, pp. 161-172, 2008, DOI:10.3970/sdhm.2008.004.161

Abstract This paper presents the details of method of sample size determination to estimate the characteristic fatigue life of aluminum alloy. The characteristic fatigue life of Aluminum alloy A356.2-T6 has been estimated by assuming a two parameter Weibull distribution model. A stepwise procedure is outlined to determine the number of specimens required at a predetermined stress amplitude to estimate the fatigue life within an acceptable error at a given probability and confidence level. The percentage of error is calculated at various probabilities and confidence levels (C.L). The probabilities considered are 50%, 90% and 95% whereas C.Ls considered are 90%, 95% and… More >