Estefanía Lidón Sánchez-Safont¹, Jennifer González-Ausejo¹, José Gámez-Pérez¹, José María Lagarón², Luis Cabedo^1*

Journal of Renewable Materials, Vol.4, No.2, pp. 123-132, 2016, DOI:10.7569/JRM.2015.634127

Abstract Novel biodegradable composites based on poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV) and different contents of purifi ed alpha-cellulose fi bers (3, 10, 25 and 45%) were prepared by melt blending and characterized. The composites were characterized by scanning electron microscopy (SEM), wide-angle X-ray scattering (WAXS) experiments, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanic analysis (DMA) and Shore D hardness measurements. Disintegrability under composting conditions was studied according to the ISO 20200 standard. Morphological results showed that high dispersion of the fi bers was achieved during mixing. Good adhesion on the fi ber-matrix interface was also detected by SEM. The addition of low… More >

Mary Isabel Lopretti^1,2*, Natalia Irene Baldyga³, Maria Gonzalez¹, Laura Beatriz Olazabal³, Marina Graciela Torres³, Fernando Resquin⁴, Leonidas Carrasco⁴

Journal of Renewable Materials, Vol.4, No.1, pp. 66-71, 2016, DOI:10.7569/JRM.2015.634133

Abstract Nowadays, there is a great interest in using lignocellulosic materials as substrate for the production of biorefi nery products. Eucalypti are good options to use as crops to obtain different kinds of biofuels and derivatives, since their plantations show high adaptation potential to soil and weather conditions in Uruguay. The basic process steps involved in the obtainment of biorefi nery materials are: pretreatment, hydrolysis, fermentation and products separation. As delignifi cation is an important process to obtain biorefi nery products, in this context the evaluation of the biological (BT) and hydrothermal (TT) pretreatment of different species of Eucaliptus was studied.… More >

Isabel Patrícia Fernandes¹, Mariana Barbosa¹, Joana Soares Amaral², Vera Pinto³, José Luís Rodrigues³, Maria José Ferreira³, Maria Filomena Barreiro^1*

Journal of Renewable Materials, Vol.4, No.1, pp. 47-56, 2016, DOI:10.7569/JRM.2015.634126

Abstract Among the wide variety of materials employed in the manufacture of shoes, thermoplastic polyurethanes (TPUs) are one of the most widely used. Given its widespread use, and associated waste management problems, the development of more biodegradable and evironmentally compatible solutions is needed. In this work, a polyester-based TPU used in the footwear industry for outsoles production was modifi ed by compounding with lignin, starch and cellulose at content of 4% (w/w). The biodegradability was evaluated by using agar plate tests with the fungi Aspergillus niger ATCC16404, the Gram-negative bacteria Pseudomonas aeruginosa ATCC9027 and an association of both (consortium), and soil… More >

Idalba A. Hidalgo A.^∗, Felipe Sojo^†, Francisco Arvelo^†, Marcos A. Sabino^∗,‡

Molecular & Cellular Biomechanics, Vol.10, No.2, pp. 85-105, 2013, DOI:10.3970/mcb.2013.010.085

Abstract The electrospinning technique is a method used to produce nano and microfibers using the influence of electrostatic forces. Porous three dimensional networks of continuous and interconnected fibers as scaffolds were obtained from a poly (lactic acid) solution. The concentration of the polymeric solution, 12.5% m/w, as well as the conditions of voltage (V=11kV) and tip-metallic collector distance (H=13cm) were established to develop these scaffolds through the electrospinning process. The characteristics of the scaffolds, such as fiber diameter, sintering and the biomimetics of the characteristics of a native extra cellular matrix were verified by Scanning Electron Microscopy (SEM). The orientation induced… More >

Lihai Zhang^*, Bruce S. Gardiner^*, David W. Smith^*, Peter Pivonka^*, Alan Grodzinsky^†

Molecular & Cellular Biomechanics, Vol.5, No.2, pp. 133-154, 2008, DOI:10.3970/mcb.2008.005.133

Abstract Cartilage maintains its integrity in a hostile mechanical environment. This task is made more difficult because cartilage has no blood supply, and so nutrients and growth factors need to be transported greater distances than normal to reach cells several millimetres from the cartilage surface. The chondrocytes embedded within the extracellular matrix (ECM) are essential for maintaining the mechanical integrity of the ECM, through a balance of degradation and synthesis of collagen and proteoglycans. A chondrocyte senses various chemical and mechanical signals in its local microenvironment, responding by appropriate adaption of the local ECM. Clearly a 'systems understanding' of cartilage behaviour… More >

Deli Gao¹, Zengxin Zhao²

CMC-Computers, Materials & Continua, Vol.26, No.2, pp. 157-166, 2011, DOI:10.3970/cmc.2011.026.157

Abstract The research on casing corrosion in sour environment by a synergism of sweet corrosion and H₂S corrosion has become the basis of casing selection and casing string safety evaluation with more and more sour reservoirs containing high H₂S concentration being developed. It is essential to scientifically utilize casing service ability and reasonably control production rate of gas well to achieve the effective and safe developing of gas resources during the safety period of casing service with a precise casing life prediction. Scanning electron microscopy and tensile testing were applied to investigate the corrosion of TP110TS tube steel in stimulant solution… More >

Shamsh Tabrez, Mira Mitra, S. Gopalakrishnan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.22, No.1, pp. 77-90, 2007, DOI:10.3970/cmes.2007.022.077

Abstract In this paper, wave propagation is studied in degraded composite beam due to moisture absorption. The obtained wave responses are then used for diagnosis of the degraded zone. Moisture absorption causes an irreversible hygrothermal deterioration of the material. The change in temperature and moisture absorption changes the mechanical properties. Thus this affects the structure in dimensional stability as well as material degradation due to reduction in mechanical properties. Here, the composite beam is modeled as Timoshenko beam using wavelet based spectral finite element (WSFE) method. The WSFE technique is especially tailored for simulation of wave propagation. It involves Daubechies scaling… More >

Huanchun Chen¹, Kunigal Shivakumar¹

CMC-Computers, Materials & Continua, Vol.8, No.1, pp. 33-42, 2008, DOI:10.3970/cmc.2008.008.033

Abstract Thermal cycling degradation effect on tensile and flexural properties of Cytec T650 carbon/Lonza Primaset PT-30 cyanate ester composite rods used for gas turbine engine brush seals was evaluated. The composite rods were thermal cycled in air from room temperature to 315°C for 100, 200, 400, 600 and 800 cycles. Each thermal cycle is a one hour period with 28 minutes hold at peak temperature and a high heating/cooling rate of 73°C/min. The composite withstood the first 100 thermal cycles with less than 10% property change. After that, tensile strength and fracture strain as well as flexural modulus were gradually reduced.… More >

Ramana M. Pidaparti^1,2, Evan J. Neblett²

CMC-Computers, Materials & Continua, Vol.5, No.1, pp. 1-10, 2007, DOI:10.3970/cmc.2007.005.001

Abstract A neural network (NN) model is developed for the analysis and prediction of the mapping between degradation of chemical elements and electrochemical parameters during the corrosion process. The input parameters to the neural network model are alloy composition, electrochemical parameters, and corrosion time. The output parameters are the degradation of chemical elements in AA 2024-T3 material. The NN is trained with the data obtained from Energy Dispersive X-ray Spectrometry (EDS) on corroded specimens. A very good performance of the neural network is achieved after training and validation with the experimental data. After validating the NN model, simulations were carried out… More >

Thanh Q. Nguyen^1,2, Thao T. D. Nguyen³, H. Nguyen-Xuan^4,5,*, Nhi K. Ngo^1,2

CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 27-53, 2019, DOI:10.32604/cmc.2019.07756

Abstract This paper presents a new approach using correlation and cross-correlation coefficients to evaluate the stiffness degradation of beams under moving load. The theoretical study of identifying defects by vibration methods showed that the traditional methods derived from the vibration measurement data have not met the needs of the actual issues. We show that the correlation coefficients allow us to evaluate the degree and the effectiveness of the defects on beams. At the same time, the cross-correlation model is the basis for determining the relative position of defects. The results of this study are experimentally conducted to confirm the relationship between… More >