Kerlin P. Robert¹, Jiaoyan Li², James D. Lee^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 74-74, 2019, DOI:10.32604/mcb.2019.07125

Abstract This presentation focuses on the new and upcoming concept of 4D printing and its vast scope and importance in the research and development in industry. The 3D printing object is considered as a layered structure. Each layer may have different orientation. Therefore each layer may behave differently under the change of its environment. We formulate the theoretical shape changing process of 4D printing resulted from (I) the biological growth or swelling, (II) the change of temperature, and (III) the effect of electric field on piezoelectric material of the 3D printing product. Then we illustrate this theory visually through finite element… More >

Fuyao Yan^{1, #}, Yu hin Chan^2,#, Abhinav Saboo³ , Jiten Shah⁴, Gregory B. Olson^{1, 3}, Wei Chen^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.3, pp. 343-366, 2018, DOI:10.31614/cmes.2018.04452

Abstract Predicting the mechanical properties of additively manufactured parts is often a tedious process, requiring the integration of multiple stand-alone and expensive simulations. Furthermore, as properties are highly location-dependent due to repeated heating and cooling cycles, the properties prediction models must be run for multiple locations before the part-level performance can be analyzed for certification, compounding the computational expense. This work has proposed a rapid prediction framework that replaces the physics-based mechanistic models with Gaussian process metamodels, a type of machine learning model for statistical inference with limited data. The metamodels can predict the varying properties within an entire part in… More >

V. Venkatachalam^{1, *}, D. Prabhakaran¹

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.3, pp. 321-334, 2018, DOI:10.3970/cmes.2018.114.321

Abstract This paper presents, using Lyapunov-Krasovskii functional technique combined with reciprocal convex lemma is considered for a networked control temperature control system with additive time-varying-delays. In the stability analysis, a new LK functional is assumed, and take the time-derivative of the (LK) functional, using reciprocal convex combination technique was employed to obtain less conservative stability criteria. Finally, the proposed stability analysis culminates into a stability criterion in the LMI (linear matrix inequalities) framework. The results obtained are in accordance with the theoretically obtained in the temperature control system and they are closer to the standard benchmark temperature-control system. More >

Takéhiko Nakama¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.4, pp. 233-242, 2009, DOI:10.3970/icces.2009.009.233

Abstract Random noise perturbs objective functions in a variety of practical optimization problems, and genetic algorithms (GAs) have been widely proposed as an effective optimization tool for dealing with noisy objective functions. In this paper, we investigate GAs applied to objective functions that are perturbed by multiple sources of additive and multiplicative noise that each take on finitely many values. We reveal the convergence properties of GAs by constructing and analyzing a Markov chain that explicitly models the evolution of the algorithms in noisy environments. Our analysis shows that this Markov chain is indecomposable; it has only one positive recurrent communication… More >

Juan Carlos Torres Lozada*

Journal of Renewable Materials, Vol.7, No.6, pp. 523-525, 2019, DOI:10.32604/jrm.2019.04053

Abstract This paper presents the patent of a new additive for the construction industry, which is obtained from the biomass residues of the wood industry. This additive is biodegradable and has fluidifying, foaming, plasticizing and stabilizing properties. When the additive is mixed with cement binder compositions, cement mortar and concrete, lightweight, flame-retardant cellular materials, thermal and acoustic insulators are obtained. More >

Xin Feng, Yichao Hu, Zhengfeng Cao, Yanqiu Xia*

Journal of Renewable Materials, Vol.7, No.5, pp. 441-449, 2019, DOI:10.32604/jrm.2019.04881

Abstract Three kinds of crop leaf-surface waxes were extracted from wheat, corn and broomcorn leaves, respectively. The crop leaf-surface waxes as lubricant additives were added to synthetic ester and the friction and wear properties of prepared lubricants for steel-aluminum and steel-copper friction pair were investigated in detail. The scanning electron microscopy (SEM) and secondary ion mass spectrometry (SIMS) were employed to explore the friction mechanisms. The results show that crop leaf-surface waxes could successfully reduce the friction and wear of steel-aluminum and steel-copper sliding friction pairs as compared with pure synthetic ester. For example, when the concentration of wheat leaf-surface wax… More >

D. Vassilev^1,*, N. Petkova², M. Koleva¹, P. Denev²

Journal of Renewable Materials, Vol.6, No.7, pp. 707-714, 2018, DOI:10.32604/JRM.2018.00015

Abstract The paper presents the findings of an experimental study on the microwave synthesis (MW) of inulin acetate and its possible application as bio-additive in poly(vinyl chloride) (PVC). The obtained inulin acetate has been identified and characterized by spectroscopic methods. Advantages of the MW compared with the conventional synthesis were defined. In order to evaluate possible application of the product as bio-based additive for polymers, effect of the inulin ester on PVC behavior and characteristics has been investigated by differential scanning calorimetry (DSC) and deformation upon extension. Experimental results show that in concentration range up to 30.0 wt. % the inulin… More >

Heather L. Buckley^1*, Caitlin H. Touchberry², Jonathan P. McKinley², Zachary S. Mathe¹, Hurik Muradyan¹, Hannah Ling², Raj P. Fadadu¹, Martin J. Mulvihill¹, Susan E. Amrose²

Journal of Renewable Materials, Vol.5, No.1, pp. 1-13, 2017, DOI:10.7569/JRM.2016.634109

Abstract Waste cardboard is an underutilized resource that can be redirected for the creation of safer and higher quality building materials for low-income housing in the developing world, as well as to produce better materials for indoor environments in developed-world contexts. Using a renewable biobased binder and benign additives, we have improved the water resistance of a cardboard-based composite material, overcoming one of the major barriers to scaling and adoption of this class of materials. Resistance to water uptake was significantly increased with several additives and was increased over 900-fold in the best case. Strength and water uptake over time are… 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 >

Flávio Pereira¹, João Pereira², Nádia Paiva³, João Ferra³, Jorge Manuel Martins^1,4, Fernão D. Magalhães¹, and Luísa Carvalho^1,4*

Journal of Renewable Materials, Vol.4, No.1, pp. 41-46, 2016, DOI:10.7569/JRM.2015.634128

Abstract This work studies the use of soy protein as a natural formaldehyde scavenger in wood particleboard production. The protein is incorporated in two forms: a) as a powder, during the blending process of wood particles with urea-formaldehyde binder resin, and b) as an aqueous solution, added at different times during resin synthesis. Analysis of variance (ANOVA) was used to evaluate the signifi cance level of two effects (amount of added soy and time of addition) on internal bond strength, thickness swelling, and formaldehyde content of the resulting panels. The results showed that soy protein can contribute to decrease the formaldehyde… More >