L. Poussard^1,*, A. Mecheri¹, J. Mariage¹, I. Barakat¹, L. Bonnaud¹, J.-M. Raquez^1,2, P. Dubois^1,2

Journal of Renewable Materials, Vol.2, No.1, pp. 13-22, 2014, DOI:10.7569/JRM.2013.634132

Abstract Biobased oligo(butylene succinate)-based thermoplastic polyurethanes (TPUs) were prepared following a twostep polymerization process: condensation of succinic acid and butanediol and the chain extension of resulting hydroxyl-terminated butylene succinate oligomers (OBS) in the presence of butanediol as chain extender and isophorone diisocyanate (IPDI) as coupling agent. Mechanical and thermal properties of the elaborated TPUs were evaluated in terms of hard segment and compared with those of commercial polybutylene succinate (PBS), Bionolle 1001. Whatever the compositions, the ultimate tensile properties of OBS-based TPUs and Bionolle 1001 were found to exhibit similar values (ε_r ≈ 400%, σ_r ≈ 40 More >

V. K. Srivastava¹, A. Pizzi^2,3,*

Journal of Renewable Materials, Vol.2, No.3, pp. 201-206, 2014, DOI:10.7569/JRM.2014.634107

Abstract Fine wood powder/furanic foams were prepared with a strong predominance of the wood component. Low weight and density are important properties of foamed composites. Focusing on preparing light materials, wood foam composites were made using a chemical foaming method and expanded using diethyl ether as the foaming agent. The additives were added to note their effect on the density and mechanical properties, like impact strength and Young’s moduli, of the expanded composites. Various tests and scanning electron microscopy analysis were also performed. The foaming agent resulted in closed cells with varied sizes and more or More >

Marion Noël^1,*, Warren Grigsby², Thomas Volkmer¹

Journal of Renewable Materials, Vol.2, No.4, pp. 291-305, 2014, DOI:10.7569/JRM.2014.634118

Abstract Oligomer systems based on poly(lactic acid) (PLA), poly(glycolic acid) (PGA), poly(butylene succinate) (PBS) and poly(butylene adipate) (PBA) were impregnated in wood and polymerized in situ to improve the dimensional stability of the treated wood. Dynamic mechanical thermal analysis (DMTA) was used to characterize the impact on the treated wood properties. Cell wall bulking treatments (PLA and PGA oligomers: OLA and OGA) induced softening and plasticization of wood components. Lumen fi lling treatments (PBS and PBA oligomers: OBS and OBA) led to minor decreases in treated wood stiffness with any softening dependent on the polymer melt More >

M. Tazi¹, F. Erchiqui^1,*, F.Godard¹, H. Kaddami²

Journal of Renewable Materials, Vol.2, No.4, pp. 258-263, 2014, DOI:10.7569/JRM.2014.634120

Abstract This article evaluates the mechanical properties and biodegradability of wood-plastic composite materials made from sawdust and thermoplastic polymer (HDPE). For the preparation of the composites, sawdust in different proportions with Maleic Anhydride grafted Polyethylene (MAPE) as the coupling agent was used. The mechanical properties and biodegradability of the biocomposites were successively characterized. The results indicate that adding sawdust particles to a polymer matrix improves the mechanical strength and stiffness of composites. The tensile strength of a composite with 3% coupling agent was improved by 13%, 34% and 54% respectively when 20%, 30% and 40% wood… More >

Amar Boukerrou^*, Dalila Hammiche, Djidjelli Hocine, Hassina Aouat

Journal of Renewable Materials, Vol.2, No.4, pp. 249-257, 2014, DOI:10.7569/JRM.2014.634119

Abstract The lack of compatibility between cellulose fi bers and some polymers, such as thermoplastics, is due on one hand to the hydrophilic nature of the vegetable fi bers and on the other hand to the hydrophobic character of the matrix. This incompatibility induces bad dispersion of the fi bers and the formation of a heterogeneous material with mechanical properties which are not very satisfactory. The scope of this article is to describe the possibility of using Olive Husk Flour (OHF) as reinforcement in the elaboration of a composite material based on polyvinyl chloride (PVC). In More >

Vincenzo Gulizzi^1,2, Piervincenzo Rizzo^2,3, Alberto Milazzo⁴

Structural Durability & Health Monitoring, Vol.10, No.1, pp. 19-54, 2014, DOI:10.3970/sdhm.2014.010.019

Abstract The electromechanical impedance (EMI) method is one of the many nondestructive evaluation approaches proposed for the health monitoring of aerospace, civil, and mechanical structures. The method consists of attaching or embedding one or more wafer-type piezoelectric transducers (PZTs) to the system of interest, the host structure, and measuring certain electrical characteristics of the transducers. As these characteristics are also related to the impedance of the host structure, they can be used to infer the mechanical properties of the monitored structure. In the study presented in this paper, we utilize the EMI to monitor the quality… More >

Shasha Yang, Shengping Shen¹

CMC-Computers, Materials & Continua, Vol.40, No.3, pp. 219-239, 2014, DOI:10.3970/cmc.2014.040.219

Abstract As well known, gradient theories can describe size effects that are important in nano-scale problems. In this paper, we analyze the Eshelby-type anti-plane inclusion problem embedded in infinite dielectric body by considering both strain gradient and electric field gradient effects to account for the size effect and high-order electromechanical coupling effect. The size-dependent Eshelby and Eshelby-like tensor, strain, stress, electric field and electric displacement components are derived explicitly by means of Green's function method. Theoretical results indicate that strain and electric field are decoupled for anti-plane inclusion problem while stress field and electric displacement are More >

Y. Zhang¹, Y. F. Nie², Y. T. Wu¹

CMC-Computers, Materials & Continua, Vol.40, No.3, pp. 203-218, 2014, DOI:10.3970/cmc.2014.040.203

Abstract The present study aims to evaluate the mechanical properties of steel fiber reinforced concrete (SFRC) by the statistical second-order two-scale (SSOTS) method. At first, the representation for microstructure of SFRC is described by a concept of statistical screen. According to the microstructure representation, the SSOTS method is displayed in a concise way. This method is on the basis of asymptotic expansion homogenization and Monte Carlo method, and can calculate the local strain and stress field through the two-order displacement solution. As the classical homogenization method, the expression of homogenized elastic modulus is derived analytically. Then More >

R. Allena^*,†

Molecular & Cellular Biomechanics, Vol.11, No.3, pp. 185-208, 2014, DOI:10.3970/mcb.2014.011.185

Abstract Confined migration is a crucial phenomenon during embryogenesis, immune response and cancer. Here, a two-dimensional finite element model of a HeLa cell migrating across constricted–curved micro-channels is proposed. The cell is modelled as a continuum with embedded cytoplasm and nucleus, which are described by standard Maxwell viscoelastic models. The decomposition of the deformation gradient is employed to define the cyclic active strains of protrusion and contraction, which are synchronized with the adhesion forces between the cell and the substrate. The micro-channels are represented by two rigid walls and exert an additional viscous force on the… More >

Norizadeh Abbariki Tannaz^*,†, Shokrgozar Mohammad Ali^†,‡, Haghighipour Nooshin^*,§, Aghdami Nasser^¶, Mahdian Rezak^II, Amanzadeh Amir^*, Jazayeri Maryam^*,†

Molecular & Cellular Biomechanics, Vol.11, No.1, pp. 19-37, 2014, DOI:10.3970/mcb.2014.011.019

Abstract Background: Environmental factors affect stem cell differentiation. In addition to chemical factors, mechanical signals have been suggested to enhance myogenic differentiation of stem cells. Therefore, this study was undertaken to illustrate and compare the effect of chemical and mechanical stimuli on Myogenin (MyoG) and Myosin heavy chani 2 (Myh2) expression of mouse bone marrowderived mesenchymal stem cells (BMSCs) and embryonic stem cells (ESCs). Methods: After isolation and expansion of BMSCs and generation of embryoid bodies and spontaneous differentiation of ESCs, cells were examined in 4 groups: (1) control group: untreated cells; (2) chemical group: cells… More >