Y. T. Wu¹, J. Z. Cui², Y. F. Nie³, Y. Zhang³

CMC-Computers, Materials & Continua, Vol.42, No.3, pp. 205-226, 2014, DOI:10.3970/cmc.2014.042.205

Abstract Core–shell particle–filled PA6/EPDM–g–MA/HDPE ternary blend has excellent mechanical properties. In this paper, effective elastic properties and tensile yield strength of the ternary blend are predicted by the second–order two– scale method, to investigate the relationship between morphology and mechanical properties. The method and the limit analysis for predicting mechanical properties of random heterogeneous materials are briefly introduced. Realistic morphology of the ternary blend including both core–shell particles and pure particles is simulated, and finite element mesh is generated. The unified strength theory is embedded in the method for the convenience of selecting a suitable yield More >

S. Zhao¹, Zichun Yang^1,2, X. G. Zhou³, X. Z. Ling⁴, L. S. Mora⁵, D. Khoshkhou⁶, J. Marrow⁵

CMC-Computers, Materials & Continua, Vol.42, No.2, pp. 103-124, 2014, DOI:10.3970/cmc.2014.042.103

Abstract Continuous SiC fiber reinforced SiC matrix composites (SiC/SiC) have been studied and developed for high temperature and fusion applications. Polymer impregnation and pyrolysis (PIP) is a conventional technique for fabricating SiC/SiC composites. In this research, KD-1 SiC fibers were employed as reinforcements, a series of coatings such as pyrocarbon (PyC), SiC and carbon nanotubes (CNTs) were synthesized as interphases, PCS and LPVCS were used as precursors and SiC/SiC composites were prepared via the PIP method. The mechanical properties of the SiC/SiC composites were characterized. Relationship between the interphase shear strength and the fracture toughness of More >

Amar Prakash¹, Srinivasan, S. M.², Rama Mohan Rao, A.³

CMC-Computers, Materials & Continua, Vol.42, No.1, pp. 75-102, 2014, DOI:10.3970/cmc.2014.042.075

Abstract Behaviour of layered steel fibre reinforced cementitious composite (SFRCC) panels is studied under high velocity impact of short projectiles. The panels consist of slurry infiltrated fibre concrete (SIFCON) layers in external faces and an intermediate (core) layer of latex modified concrete (LMC) and steel wire mesh embedded in cement sand slurry. In order to minimize acoustic impedance mismatch at the interfaces, judiciously selected materials are provided in the layers with appropriate lay-up sequences. For relative evaluation of high velocity impact performances of these panels', impact experiments are conducted in controlled environment. Two most commonly used… More >

Shiv Narayan¹, Latha S.¹ and R M Jha¹

CMC-Computers, Materials & Continua, Vol.39, No.3, pp. 217-230, 2014, DOI:10.3970/cmc.2014.039.217

Abstract The EM analysis of multi-layered metamaterial based radar absorbing structure (RAS) with dual-band characteristics in millimeter wave frequency regime has been carried out in this paper using transmission line transfer matrix (TLTM) method for TE and TM polarizations. The proposed metamaterial-based RAS exhibits dual-band characteristics at centre frequencies 120 GHz and 175 GHz with very low power reflection. It absorbs more than 90% power of incidence wave over the frequency range from 111-131 GHz at first resonance and from 164.5-185 GHz at second resonance without metal backing plate, which is desirable for stealth applications. It More >

Jingguo Yan¹, Xudong Wang¹, Man Yao^1,2, Ning Hu^3,4

CMC-Computers, Materials & Continua, Vol.39, No.1, pp. 73-84, 2014, DOI:10.3970/cmc.2014.039.073

Abstract Electronic structure and magnetism of the rare-earth metals Ac and Th doped Fe₃O₄ Fe_1-xRe_xFe_2-yRe_yO₄(Re=Ac, Th; x=0, 0.5, 1; y=0, 0.5, 1.0, 1.5, 2.0) are investigated by first-principle calculations. AcFe₂O₄, FeAc₂O₄ and ThFe₂O₄ are found to be II B-type half-metals. The large bonding-antibonding splitting is believed to be the origin of the gap for AcFe₂O₄, FeAc₂O₄ and ThFe₂O₄, resulting in a net magnetic moment of 9.0μ_B, 4.0μ_B and 8.1μ_B, respectively, compared with 4.0μ_B of Fe₃O₄. Also, the conductance of AcFe₂O₄ and ThFe₂O₄ are both slightly larger than that of Fe3O4. It can be predicted that the new rare-earth half-metals AcFe₂O₄ and ThFe₂O₄ have wider application More >

J. Aubry¹, P. Navarro¹, S. Marguet¹, J.-F. Ferrero¹, O. Dorival², L. Sohier³, J.-Y. Cognard³

CMC-Computers, Materials & Continua, Vol.39, No.1, pp. 21-47, 2014, DOI:10.3970/cmc.2014.039.021

Abstract In this paper a numerical model dedicated to the simulation of the mechanical behaviour of polymeric Rohacell foams is presented. The finite elements model is developed at the scale of the microstructure idealized by a representative unit cell: the truncated octahedron. Observations made on micrographs of Rohacell lead to mesh this representative unit cell as a lattice of beam elements. Each beam is assigned a brittle linear elastic mechanical behaviour in tension and an elastoplastic behaviour in compression. The plasticity in compression is introduced as a way to mimic the buckling of the edges of More >

Thomas J. Nelson, Lindsey Bultema, Neal Eidenschink, Dean C. Webster^*

Journal of Renewable Materials, Vol.1, No.2, pp. 141-153, 2013, DOI:10.7569/JRM.2013.634113

Abstract Bio-based polyols with high functionality were successfully synthesized by ring-opening epoxidized sucrose esters of soybean oil with methanol under acidic conditions, and were subsequently formulated with blocked isocyanates to form one package polyurethanes (1KPU). The bio-based polyols were characterized by gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1 H-NMR) spectroscopy, and Brookfi eld viscosity. Bio-based coatings were prepared by formulating the polyols with blocked polyisocyanates based on isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI). Two types of bio-based polyols were synthesized and the ratio of NCO:OH functional groups was More >

Silvana L. D’AMICO¹, Patricia I. LEONARDI ^1,2*, Eduardo J. CÁCERES¹

BIOCELL, Vol.37, No.3, pp. 85-90, 2013, DOI:10.32604/biocell.2013.37.085

Abstract This is the first comprehensive ultrastructural study on dwarf males with external gametangia in the ge in the genus Oedogonium, from androspore germination to the liberation of mature male gametes. The ultrastructure of the process in O. macrandrium Wittrok is similar to that of Bulbochaete hiloensis (Nordstedt) Tiffany, butwith two remarkable differences. In O. macrandrium : 1) instead of a true transverse wall, only condensed mucilage appears between the gametes of each antheridial cell, and 2) the cell wall between the basal cell and the basal most antheridial cell has simple plasmodesmata similar to those More >

Li G, FT Yang, XL Jiang, FX Chen, TH Cao, LC Wang

Phyton-International Journal of Experimental Botany, Vol.82, pp. 243-247, 2013, DOI:10.32604/phyton.2013.82.243

Abstract The aim of this study was to evaluate the impact of the plow pan on the production of spring corn. We evaluated SPAD values and chloroplast ultrastructure in premature ear leaves of spring maize at the grain-filling stage. The maize plants were grown in simulated plow pan or simulated subsoiling treatments. Plants in the simulated plow pan treatment showed irreversible damage to chloroplasts, including changes in chloroplast shape, disintegration and rupture of chloroplast membranes, and blurriness and cloudiness of grana lamellae. The chlorophyll content decreased, which is a typical characteristic of senescence. Subsoiling cultivation practices More >

Fangyi Li^1,2, Zhen Luo³, Jianhua Rong¹, Lin Hu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.6, pp. 453-482, 2013, DOI:10.3970/cmes.2013.095.453

Abstract This paper aims to propose a non-probabilistic reliability-based multiobjective optimization method for structures with uncertain-but-bounded parameters. A combination of the interval and ellipsoid convex models is used to account for the different groups of uncertain parameters, in which the interval model accounts for uncorrelated parameters, while the ellipsoid model is applied to correlated parameters. The design is then formulated as a nested double-loop optimization problem. A multi-objective genetic algorithm is used in the out loop optimization to optimize the design vector for evaluating the objectives, and the Sequential Quadratic Programming (SQP) algorithm is applied in… More >