T. Côto¹, I. Moura¹, A. de Sá^1,*, C. Vilarinho², A. V. Machado¹

Journal of Renewable Materials, Vol.6, No.7, pp. 688-696, 2018, DOI:10.32604/JRM.2018.00006

Abstract Biopolymers exhibit unique properties and can be produced from plants’ and crops’ wastes. Cellulose has been used for the production of sustainable materials, nevertheless due to the difficulty inherent to its extraction, several methods have been studied in order to optimize the process. Therefore, this paper reports the extraction of natural polymers from food sector agro-food wastes, including cellulose, following a green chemistry aproach. The cellulose extracted from pumpkin peel was acetylated and dispersed in a polylactic acid (PLA) matrix. The developed materials were characterized in terms of their structure, morphology and thermal stability. The More >

Maha L. Shrestha¹, Mihail Ionescu^1*, Xianmei Wan¹, Nikola Bilić¹, Zoran S. Petrović¹, Tom Upshaw²

Journal of Renewable Materials, Vol.6, No.1, pp. 87-101, 2018, DOI:10.7569/JRM.2017.634153

Abstract Cardanol is a natural phenol which is obtained from high vacuum distillation of cashew nut shell liquid. It contains a hydrocarbon chain of 15 carbon atoms in the meta position, either with one, two or three non-conjugated double bonds. This article describes thermal thiol-ene reaction to synthesize new cardanol-based polyols for polyurethanes with aromatic-aliphatic structure. Phenolic hydroxyl group was blocked by alkoxylation and 2-mercaptoethanol was added to the double bonds of propoxylated cardanol. The resultant product is a mixture of polyols that may contain one, two, three or four hydroxyl groups, as a function of the More >

T. Chekifi^1,2,*, B. Dennai², R. Khelfaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.3, pp. 201-212, 2018, DOI:10.3970/fdmp.2018.00322

Abstract The fluidic oscillator is an interesting device developed for passive flow measurement. These microsystems can produce a high oscillating jet frequency with high flow velocity. The main advantages of fluidic oscillators are that no moving parts is included in the device. Commercial CFD code FLUENT was used to perform analysis of flows in fluidic oscillator. Numerical simulations were carried out for different flow conditions, where water and air were used as working fluids. The oscillation frequencies were identified by the discrete fast Fourier transform method (FFT). Furthermore a low-pressure vortex of fluid flow in the More >

Fakher Oueslati^a,b,†, Brahim Ben-Beya^b

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-11, 2017, DOI:10.5098/hmt.8.38

Abstract The current study deals with a numerical investigation of magnetoconvection and entropy generation within a lid driven square cavity subject to uniform magnetic field and filled with liquid metal. Effects of multiple parameters namely; the Prandtl, Hartmann and Richardson numbers were predicted and analyzed using a numerical methodology based on the finite volume method and a full multigrid technique. The numerical outcome of the present study shows that, the enhancement of Hartmann number declines the heat transfer rate for all liquid metals considered. Moreover, it is observed that augmenting the Richardson number leads to acceleration More >

Asghar Esmaeeli¹, Ali Behjatian¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.3, pp. 143-153, 2017, DOI:10.3970/fdmp.2017.013.143

Abstract The evolution of the flow field in and around a liquid drop in a unifor-m electric field for fluid systems corresponding to region (II) of the circulation-deformation map is fundamentally different than that for the rest of the map and has not been explored before. This is examined here and justified mathematical-ly. Furthermore a methodology is developed to predict the flow pattern, which is likely to be helpful in predicting the evolution of the flow field in more complex circumstances. More >

Oscar F. Aguilar Gutierrez, Alejandro D. Rey^*

Journal of Renewable Materials, Vol.4, No.4, pp. 241-250, 2016, DOI:10.7569/JRM.2016.634119

Abstract Biological plywoods are solid analogues of liquid crystalline phases whose building blocks, including cellulose, collagen and chitin, present multifunctionality, providing in some cases protection, camouflage, self-healing and/or adaptability to the surrounding environment. The 3D ordered structure is the main factor for these fascinating properties, and the assessment of the structure-property relationship will be a powerful tool in terms of future material design and innovation. Cross-section observations lead to characteristic patterns depending on the specific arrangement of the plywood’s building blocks. Twisted plywood architectures, known as the Bouligand structure, lead to the widely observed arced patterns… More >

Yogesh K. Murugesan¹, Damiano Pasini², Alejandro D. Rey^1,*

Journal of Renewable Materials, Vol.3, No.1, pp. 56-72, 2015, DOI:10.7569/JRM.2014.634124

Abstract This review on self-assembly in biological fi brous composites presents theory and simulation to elucidate the principles and mechanisms that govern the thermodynamics, material science, and rheology of biological anisotropic soft matter that are involved in the growth/self-assembly/material processing of these materials. Plant cell wall, a multi-layered biological fi brous composite, is presented as a model biological system to investigate self-assembly mechanisms in nature’s material synthesis. In order to demonstrate the universality of the presented models and the mechanisms investigated, references to other biological/ biomimetic systems are made when applicable. The integration of soft matter More >

J. Wang^1,2, P. Simacek^1,2, S.G. Advani^1,2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.1, pp. 59-79, 2015, DOI:10.3970/cmes.2015.107.059

Abstract In Liquid Composite Molding (LCM) processes, resin is introduced into a stationary fiber reinforcement placed in the mold, until the reinforcement gets fully saturated with resin and all volatiles are vented out of the part. Finite element based software packages have been developed to simulate the mold filling process and eliminate expensive and tedious trial and error practices to arrive at a successful mold filling without any voids. However, the non-homogeneity of the fiber reinforcement material and its placement and layup in the mold creates a large degree of variability of flow patterns during the… More >

V. N. Lad¹, Z. V. P. Murthy^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 241-255, 2015, DOI:10.3970/fdmp.2015.011.241

Abstract Free liquid jets are of great technical importance in a variety of applications like ink-jet printing, glass painting, spray coating and metal cutting. Here we consider the changes induced in the dynamics of such jets by the presence of obstructions at the tube exit. Using stainless steel bars of 1.5 mm diameter as obstruction objects and aqueous solutions of glycerol of varying concentrations as working fluids, we performed experiments for different configurations, including a single rod at the centre of the tube exit, two parallel rods equidistant from the centre of the tube, and a… More >

Yuan Chen¹, Honggang Duan¹, Fei Yu¹, Xingyu Zhao¹, Han Xu¹, Jun Gao^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 127-142, 2015, DOI:10.3970/fdmp.2015.011.127

Abstract The dynamics of dispersed bubbles in a centrifugal separator are investigated with the aim to improve the efficiency of the system. The prototype separator consists of a rotor, a base, a diverting disc, a shaft, an oil trapping impeller, a central pipe, an inlet section for contaminated oil, an outlet section for purified oil and an air outlet. A hydrodynamic model is developed to predict the complex influence of parameters such as the centrifugal force and vacuum pressure. In particular, three different force models are selected to analyze the effect of the added mass and More >