Cansu Ulker*, Yuksel Guvenilir

Journal of Renewable Materials, Vol.6, No.6, pp. 591-598, 2018, DOI:10.7569/JRM.2017.634189

Abstract As an alternative biodegradable aliphatic polyester, poly(w-pentadecalactone-co-ε-caprolactone) copolymer was synthesized via enzymatic ring-opening polymerization. A new biocatalyst, Candida antarctica lipase B, immobilized onto rice husk ash was used for catalysis. Reactions were carried out at various temperatures and periods for varied copolymer compositions in order to obtain the highest molecular weight copolymer. The best reaction parameters were found to be 80 °C and 6 hours and molecular weights increased proportionally with the amount of w-pentadecalactone (w-PDL). The molecular structure of copolymer with 75% weight ratio of w-PDL (Mn = 19720 g/mol) was characterized by proton and carbon nuclear magnetic resonance… More >

Sibi Chacko¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.1, pp. 33-44, 2009, DOI:10.3970/icces.2009.009.033

Abstract In this work, dynamic analysis of a compliant shaft while it rotates about its axis has been carried out using Finite Element Method. This system is linear time invariant gyroscopic system. The governing equations are formulated for the shaft supported at both ends. Both ends of the shaft are supported to allow rotations by constraining all degrees of freedom, except axial rotations. The shaft is modeled using beam elements, with six degrees of freedom at the nodes. The effect of rotation on displacements is analysed by assessing the total kinetic energy and potential energy. In this work dynamic response of… More >

Haiyi Liang¹, C.H. Woo^1,2, Hanchen Huang³, A.H.W. Ngan⁴, T.X. Yu⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.1, pp. 105-114, 2004, DOI:10.3970/cmes.2004.006.105

Abstract Molecular dynamics (MD) simulations are performed to study crystalline plasticity during nano-indentation by comparing the elastic-plastic response of three copper substrates with surfaces (001), (110), and (111) crystallographic planes. The effects of elastic anisotropy and crystallographic symmetry on the reduced modulus, dislocation nucleation, and subsequent microstructure evolution, are investigated. The reduced modulus of (111) surface is found to be the largest, while that of (001) surface is the smallest. Elastic stress distribution calculated from finite element method (FEM) is qualitatively consistent with the MD simulation results. Significant differences exist in the deformation behavior in the three different crystallographic orientations. The… More >

Youping Chen¹, James D Lee², Azim Esk,arian¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.1, pp. 35-44, 2004, DOI:10.3970/cmes.2004.005.035

Abstract This paper addresses the need of theories and simulations for material body of mesoscopic and microscopic sizes. An overview of polar theories is presented. The micropolar theory proposed by Eringen is introduced and compared with other polar theories. Constitutive equations of micropolar thermo-visco-elastic solid are derived. Finite element analyses have been performed for a few sample problems with wide range of length scales. Based on the discussion, comparison and computer simulations, the unique feature and applicability of micropolar theory are demonstrated. More >

Weijin Tan^1,*, Yunqing Wu¹, Peng Wu¹, Beijing Chen^1,2

Journal of New Media, Vol.1, No.1, pp. 11-25, 2019, DOI:10.32604/jnm.2019.06219

Abstract Digital images can be tampered easily with simple image editing software tools. Therefore, image forensic investigation on the authenticity of digital images’ content is increasingly important. Copy-move is one of the most common types of image forgeries. Thus, an overview of the traditional and the recent copy-move forgery localization methods using passive techniques is presented in this paper. These methods are classified into three types: block-based methods, keypoint-based methods, and deep learning-based methods. In addition, the strengths and weaknesses of these methods are compared and analyzed in robustness and computational cost. Finally, further research directions are discussed. More >

Claudio Gioia*, Maria Barbara Banella, Grazia Totaro, Micaela Vannini, Paola Marchese, Martino Colonna, Laura Sisti, Annamaria Celli

Journal of Renewable Materials, Vol.6, No.1, pp. 126-135, 2018, DOI:10.7569/JRM.2017.634191

Abstract New fully biobased polyether/esters have been synthesized by a one-pot polymerization reaction of ricinoleic acid (RA), vanillic acid (VA) and ethylene carbonate (EC). In particular, EC selectively reacts with the phenolic group of VA to obtain in-situ 4-(2-hydroxyethoxy)-3-methoxybenzoate (EV), suitable for subsequent copolymerization with RA. The procedure was carried out in a single step, without any solvent. Chemical structure and thermal properties of the new materials were studied in order to explore relationships between composition and final performances. The combination of EV, bearing a rigid aromatic structure, with RA, characterized by high flexibility and potential biocidal activity, allows the production… More >

Abha Dubey^1*, Anuradha Mishra²

Journal of Renewable Materials, Vol.5, No.1, pp. 54-61, 2017, DOI:10.7569/JRM.2016.634127

Abstract Biosorption effectively removes heavy metal ions by using inexpensive biosorbents. In this study, Portulaca oleracea plant waste biomass was used as environmentally friendly biosorbent for the removal of copper ions from aqueous solution. This article includes the study of the effects of various important parameters on the biosorption process. Maximum biosorption was found to occur under slightly acidic conditions (pH 6). Small particle size, moderate agitation speed, and moderate temperature favor the biosorption process. The Langmuir model was most suitable, showing the biosorption capacity to be 85.470 mg/g. Pseudo-secondorder model best described the kinetics of the biosorption process. Thermodynamic studies… More >

Jose Luis Orellana, Michael Mauhar, Christopher L. Kitchens^*

Journal of Renewable Materials, Vol.4, No.5, pp. 340-350, 2016, DOI:10.7569/JRM.2016.634126

Abstract Polylactic acid (PLA) is one of the most widely used biodegradable polymers due to the ability to synthesize it economically at industrial scale and its favorable properties for many consumer products. However, the rigid nature of PLA is not desirable for specific applications, requiring the incorporation of effective bioderived additives in order to enhance the PLA toughness and broaden applications. In this work, PLA was modified by graft polymerization of polyacrylic acid (PLA-g-PAA) to increase the hydrophilicity to promote compatibilization of cellulose nanocrystals (CNCs) or high molecular polyethylene glycol (PEG). CNCs were found to act as a nucleating agent for… More >

Yunfeng Chen^1,2,3,†,*, Jiexi Liao^4,†, Zhou Yuan¹, Kaitao Li⁴, Baoyu Liu⁴, Lining Arnold Ju^4,5,6, Cheng Zhu^1,2,4,*

Molecular & Cellular Biomechanics, Vol.16, No.3, pp. 211-223, 2019, DOI:10.32604/mcb.2019.07267

Abstract Force plays critical roles in cell adhesion and mechano-signaling, partially by regulating the dissociation rate, i.e., off-rate, of receptor-ligand bonds. However, the mechanism of such regulation still remains elusive. As a controversial topic of the field, when measuring the “off-rate vs. force” relation of the same molecular system, different dynamic force spectroscopy (DFS) assays (namely, force-clamp and force-ramp assays) often yield contradictive results. Such discrepancies hurdled our further understanding of molecular binding, and casted doubt on the existing theoretical models. In this work, we used a live-cell DFS technique, biomembrane force probe, to measure the single-bond dissociation in three receptor-ligand… More >

Petit Claudie¹, Guignandon Alain², Avril Stéphane^1,*

Molecular & Cellular Biomechanics, Vol.16, No.2, pp. 87-108, 2019, DOI:10.32604/mcb.2019.06415

Abstract The contractile behavior of smooth muscle cells (SMCs) in the aorta is an important determinant of growth, remodeling, and homeostasis. However, quantitative values of SMC basal tone have never been characterized precisely on individual SMCs. Therefore, to address this lack, we developed an in vitro technique based on Traction Force Microscopy (TFM). Aortic SMCs from a human lineage at low passages (4-7) were cultured 2 days in conditions promoting the development of their contractile apparatus and seeded on hydrogels of varying elastic modulus (1, 4, 12 and 25 kPa) with embedded fluorescent microspheres. After complete adhesion, SMCs were artificially detached… More >