Bruno Henrique dos Santos, Karen de Souza do Prado, Asaph Armando Jacinto, Márcia Aparecida da Silva Spinacé*

Journal of Renewable Materials, Vol.6, No.2, pp. 176-182, 2018, DOI:10.7569/JRM.2018.634101

Abstract Although thermoplastic starch (TPS) is biodegradable, its low mechanical resistance limits its wide application. Sugarcane bagasse (SB) fibers can be used as reinforcement in TPS matrix composites, but the influence of fiber size on the properties of the composite is still unknown. In this study, TPS composites reinforced with SB short fibers of four sizes were processed and characterized in order to analyze the influence of fiber size on the mechanical properties of the TPS/SB composite. It was observed that the interaction between fiber and matrix was good and optimized when the fibers are sifted in sieves between 30 and… More >

Shegufta Shetranjiwalla, Shaojun Li, Laziz Bouzidi, Suresh S. Narine^*

Journal of Renewable Materials, Vol.5, No.5, pp. 333-344, 2017, DOI:10.7569/JRM.2017.634102

Abstract The impact of polymerization protocol on phase structure and properties of entirely lipid-derived thermoplastic poly(ester urethane)s (TPEU)s was investigated. The TPEUs were synthesized from 1,7-heptamethylene diisocyanate, polyester diols and 1,9-nonanediol (ND) as chain extender. A two-stage polymerization method was used to prepare two TPEUs; one in which ND was added in the first stage of polymerization as part of the prepolymer and another in the second stage after the prepolymer was formed. Two very different morphologies exhibiting different degrees of phase separation were obtained, driven by the sequence of addition of the chain extender. The incorporation of the chain extender… More >

Liliane Cruz Gomes de Souza Santos^1*, Eliane Ayres², Flávio Renato de Góes Padula¹

Journal of Renewable Materials, Vol.5, No.3-4, pp. 307-312, 2017, DOI:10.7569/JRM.2017.634121

Abstract In this study, bamboo powder and/or hollow glass microspheres were added to thermoplastic cassava starch in order to overcome its drawbacks. The composites were characterized by scanning electron microscopy (SEM), tensile testing, water contact angle measurement and X-ray diffractometry (XRD), in addition to their thermal properties. The mechanical strength of the composites showed a general decline with increasing bamboo powder content while the water contact angles increased up to 15% of bamboo powder content (% w/w dry starch). The addition of hollow glass microspheres provides an optimal balance between hydrophobicity and mechanical strength. The results pointed to improved properties that… 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 >

Chein-Shan Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.14, No.2, pp. 77-90, 2006, DOI:10.3970/cmes.2006.014.077

Abstract In this paper we derive the first-order and second-order one-step GPS applied to the estimation of thermophysical properties. Solving the resultant algebraic equations, which usually converges within ten iterations, it is not difficult to estimate the unknown temperature-dependent thermal conductivity and heat capacity simultaneously, if some supplemented data of measured temperature at a time T is provided. When the measured temperature in the conducting slab is contaminated by noise, our estimated results are also good. The new method does not require any prior information on the functional forms of thermal conductivity and heat capacity. Numerical examples are examined to show… More >

Chein-Shan Liu¹, Li-Wei Liu², Hong-Ki Hong²

CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.1, pp. 1-18, 2007, DOI:10.3970/cmes.2007.017.001

Abstract In this paper we are concerned with the parameters identification of the inverse heat conduction problems governed by linear parabolic partial differential equations (PDEs). It is the first time that one can construct a closed-form estimation method for the inverse thermal problems of estimating the spatial-dependent thermophysical parameters. The key points hinge on an establishment of a one-step group preserving scheme (GPS) for the semi-discretization of PDEs, as well as a closed-form solution of the resulting algebraic equations. The new method, namely the Lie-group estimation method, has four advantages: it does not require any prior information on the functional forms… More >

Sayavur I. Bakhtiyarov¹, Dennis A. Siginer²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 1-22, 2009, DOI:10.3970/fdmp.2009.005.001

Abstract Strong inhomogeneous magnetic fields are necessary to generate a finite levitation force in ground based electromagnetic levitation techniques. External forces such as magnetic and gravitational forces influence the oscillation spectrum and counteract the surface movement resulting in a frequency shift, and making the use of electromagnetic levitation techniques in microgravity an attractive alternative to measure thermophysical properties of liquid metals. Under microgravity conditions the magnetic field strength around a liquid droplet is significantly lower than that required to position the same specimen against earth gravity. Hence, a low magnetic field strength results in a low amount of heat energy absorbed… More >

Sayavur I. Bakhtiyarov¹, Dennis A. Siginer²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.3, pp. 163-184, 2008, DOI:10.3970/fdmp.2008.004.163

Abstract This article has no abstract. More >

Sayavur I. Bakhtiyarov¹, Dennis A. Siginer²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 99-112, 2008, DOI:10.3970/fdmp.2008.004.099

Abstract Levitation of liquid bodies against gravity is a contactless confinement process appropriate for manufacturing very pure materials. A variety of levitation techniques have been developed over the last few decades, such as aerodynamic, acoustic, electrostatic, microwave, and electromagnetic levitations. More recently, a new generation of novel techniques, essentially combinations of the established primary techniques, has been successfully introduced. Examples are acoustic-electric, aerodynamic-acoustic and acoustic-electromagnetic. The purpose of this series of papers in three parts, Bakhtiyarov and Siginer (2007a,b), is to review the advances in electromagnetic levitation (EML) since its introduction as a containerless melting technique, and a tool for the… More >

S. Patala¹, C.A. Schuh¹

CMC-Computers, Materials & Continua, Vol.17, No.1, pp. 1-18, 2010, DOI:10.3970/cmc.2010.017.001

Abstract Recent advances in microstructural characterization have made it possible to measure grain boundaries and their networks in full crystallographic detail. Statistical studies of the complete boundary space using full crystallographic parameters (misorientations and boundary plane inclinations) are limited because the topology of the parameter space is not understood (especially for homophase grain boundaries). This paper addresses some of the complexities associated with the group space of grain boundaries, and resolves the topology of the complete boundary space for systems of two-dimensional crystals. Although the space of homophase boundaries is complicated by the existence of a `no-boundary' singularity, i.e., no boundary… More >