Stephany C. de Rezende^1,2, João A. Pinto^1,3, Isabel P. Fernandes^1,3, Fernanda V. Leimann^1,2* and Maria-Filomena Barreiro^1,3*

Journal of Renewable Materials, Vol.6, No.7, pp. 715-723, 2018, DOI:10.32604/JRM.2018.00028

Abstract Pine-fruit shell (PFS) is a lignocellulosic residue derived from the fruit of Araucaria angustifolia, a coniferous tree native of South America, part of a whole vegetation of the Atlantic Forest, found in the South and Southwest of Brazil. In this work PFS will be characterized and used in the production of PFS-based polyols through oxypropylation. Three series were chosen (PFS/propylene oxide (PO) (w/v, g/mL) of 30/70, 20/80 and 10/90) with four catalyst levels (5%, 10%, 15% and 20%, (w/w, PFS based)). Oxypropylation occurred at moderate conditions of temperature, pressure and time giving rise to liquid polyols with a homopolymer content… More >

Qiang Liu^1,*, Yanyun Zou^2,3, Xiaodong Liu⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 617-637, 2019, DOI:10.32604/cmes.2019.06272

Abstract Haze-fog, which is an atmospheric aerosol caused by natural or man-made factors, seriously affects the physical and mental health of human beings. PM_2.5 (a particulate matter whose diameter is smaller than or equal to 2.5 microns) is the chief culprit causing aerosol. To forecast the condition of PM_2.5, this paper adopts the related the meteorological data and air pollutes data to predict the concentration of PM_2.5. Since the meteorological data and air pollutes data are typical time series data, it is reasonable to adopt a machine learning method called Single Hidden-Layer Long Short-Term Memory Neural Network (SSHL-LSTMNN) containing memory capability… More >

Yong Li^1,*, Joel P. Conte², Philip E. Gill³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 517-543, 2019, DOI:10.32604/cmes.2019.06269

Abstract In the field of earthquake engineering, the advent of the performance-based design philosophy, together with the highly uncertain nature of earthquake ground excitations to structures, has brought probabilistic performance-based design to the forefront of seismic design. In order to design structures that explicitly satisfy probabilistic performance criteria, a probabilistic performance-based optimum seismic design (PPBOSD) framework is proposed in this paper by extending the state-of-the-art performance-based earthquake engineering (PBEE) methodology. PBEE is traditionally used for risk evaluation of existing or newly designed structural systems, thus referred to herein as forward PBEE analysis. In contrast, its use for design purposes is limited… More >

Davood Afshari^1,*, Soheil Mirzaahamdi¹, Zuheir Barsoum²

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.2, pp. 275-290, 2019, DOI:10.31614/cmes.2019.03880

Abstract The use of magnesium alloys has been rapidly increased due to their ability to maintain high strengths at light weights. However weldability of steels and aluminum alloys by using resistance spot weld (RSW) process is a major issue, because it cannot be directly utilized for magnesium alloys. In this study, a structural-thermal-electrical finite element (FE) model has been developed to predict the distribution of residual stresses in RSW AZ61 magnesium alloy. Thermophysical and thermomechanical properties of AZ61 magnesium alloy have been experimentally determined, and have been used in FE model to increase the accuracy of the model. X-ray diffraction (XRD)… More >

R. Rongo^1,2, D. D’Ambrosio^1,2, G. Iovine^2,3, F. Lucà⁴, V. Lupiano⁵, V.P.Boñgolan⁶, W. Spataro^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.2, pp. 105-130, 2015, DOI:10.3970/cmes.2015.109.105

Abstract Determining sectors that could be affected by lava flows in volcanic areas is essential for risk mitigation purposes. Traditionally, when adopting methods based on probabilistic numerical simulations, the hazard is assessed by analysing a huge set of simulations of hypothetical events, each characterized by a distinct probability of occurrence based on statistics of historical events. If lateral or eccentric eruptions are also taken into account, simulated lava flows usually start from the nodes of regular grids of potential vents, uniformly covering the study area. In this study, an alternative approach to evaluate flow-type hazard, based on a nonuniform grid of… More >

Tienfuan Kerh^1,2, J.S. Lai¹, D. Gunaratnam², R. Saunders²

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 1-12, 2008, DOI:10.3970/cmes.2008.026.001

Abstract Taiwan frequently suffers from strong ground motion, and the current building code is essentially based on two seismic zones, A and B. The design value of horizontal acceleration for zone A is 0.33g, and the value for zone B is 0.23g. To check the suitability of these values, a series of actual earthquake records are considered for evaluating peak ground acceleration (PGA) for each of the zones by using neural network models. The input parameters are magnitude, epicenter distance, and focal depth for each of the checking stations, and the peak ground acceleration is calculated as the output with the… More >

Ping’en Li¹, Xianyue Su^1,2, Youquan Yin¹

CMC-Computers, Materials & Continua, Vol.6, No.2, pp. 93-102, 2007, DOI:10.3970/cmc.2007.006.093

Abstract Based on the perturbation method, for flexural wave in cased hole in anisotropic formation, the alteration in the phase velocity caused by the differences in elastic constants between anisotropic formation of interest and a reference, or unperturbed isotropic formation is obtained. Assuming the cased hole is well bonded, the Thomson-Haskell transfer matrix method is applied to calculate the dispersion relation of flexural wave in cased hole in unperturbed isotropic formation. Both the cases of a fast and slow formation are considered where the symmetry axis of a transversely isotropic (TI) formation makes an angle with the cased hole axis, the… More >