Mahdi Soltanmohammadi¹, Vahid Monfared^2,*

Sound & Vibration, Vol.53, No.5, pp. 177-198, 2019, DOI:10.32604/sv.2019.05811

Abstract Dry-Type Cast Resin Distribution Transformers (CRT) is the secondgeneration of air-cooled distribution transformers where oil is replaced by resin for electrical insulation. CRT transformers may installed indoor adjacent to or near residential areas since they are clean and safe comparing to the conventional transformers. But, as it is obvious, noise discrepancy is intrinsically accompanied with all types of transformers and is inevitable for CRT transformers too. Minimization of noise level caused by such these transformers has biological and ergonomic importance. As it is known the core of transformers is the main source of the noise generation. In this paper, experimental… More >

Kyousuke Yamaguchi¹, Nao-Aki Noda², Ker-Kong Chen³, Kiyoshi Tajima³, Seiji Harada¹, Xin Lan¹

Structural Durability & Health Monitoring, Vol.5, No.3, pp. 191-200, 2009, DOI:10.3970/sdhm.2009.005.191

Abstract Wedge-shaped defects are frequently observed on the cervical region of the human tooth. Previously, most studies explained that improper tooth-brushing causes such defects. However, recent clinical observation suggested that the repeated stress due to occlusal force may induce the formation of these wedge-shaped defects. In this study, a two-dimensional human tooth model after a wedge-shaped defect is restored with the composite resin is analyzed by using the finite element method. To obtain the intensity of the singular stress accurately, a method of analysis is discussed for calculating generalized stress intensity factors, which control the singular stress around the corner of… More >

N. D. Ngo, K. K. Tamma

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.2, pp. 103-134, 2004, DOI:10.3970/cmes.2004.005.103

Abstract In the process modeling and manufacturing of large geometrically complex structural net-shaped components comprising of fiber-reinforced composite materials by Resin Transfer Molding (RTM), a polymer resin is injected into a mold cavity filled with porous fibrous preforms. The overall success of the manufacturing process depends on the complete impregnation of the fiber preform by the polymer resin, prevention of polymer gelation during filling, and subsequent avoidance of dry spots. Since the RTM process involves the injection of a cold resin into a heated mold, the associated physics encompasses a moving boundary value problem in conjunction with the multi-disciplinary study of… More >

Duning Li, Yufeng Niei?a, Xuemei Zhou, Li Cai

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 75-76, 2011, DOI:10.3970/icces.2011.019.075

Abstract In this study, the efficient discrete model including the resin infusion and the fiber compaction is developed to simulate the RFI (resin film infusion) process. The non-linear governing equations are derived by the Darcy's law, the Terzaghi's law and the continuity equations. The finite element method and the finite difference method are used to discretize the proposed equations, and the VOF method is used to track the filling front. Compared with the analytical results of Park, our numerical results agree well with them. Furthermore, we analyze the RFI process of BMI/G0814, and simulate the resin pressure, the fiber volume fraction… More >

B. J. Henz¹, D. R. Shires²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.7, No.1, pp. 13-18, 2008, DOI:10.3970/icces.2008.007.013

Abstract The capability to predict the residual stresses induced during the manufacturing process in composite components is necessary for the timely fielding of new combat systems. At the U.S. Army Research Laboratory we have developed a computational environment to model the resin flow, heat transfer, curing, and residual stresses in composite components manufactured with the resin transfer molding (RTM) process. This computational environment uses object-oriented programming methods to provide model coupling capabilities and access to high performance computing assets. In this paper we will provide details of the physical models, software, and the validation/verification procedure used to develop this RTM simulation… More >

Puyou Jia¹, Fei Song¹, Qiaoguang Li^2,*, Haoyu Xia³, Mei Li^1,*, Xugang Shu², Yonghong Zhou¹

Journal of Renewable Materials, Vol.7, No.7, pp. 601-619, 2019, DOI:10.32604/jrm.2019.07011

Abstract Polymers from renewable resources are receiving tremendous attention due to the increasing concerns on the depletion of fossil oils and deteriorated environments. Cardanol, as an abundant and renewable chemical raw material, has been widely used for the production of renewable polymer materials via converting into various of chemical monomers with active functional groups. This comprehensive review deals with various aspects of cardanol as a starting material the preparing various polymer and polymer composites such as benzoxazine resins, phenolic resin, polyurethanes, epoxy resin, vinyl ester polymers, polyamide and cyanate ester resins. The assessment of the future prospects for the use of… More >

Emanoele Maria Santos Chiromito¹, Eliane Trovatti², Antonio Jose Felix Carvalho^1,*

Journal of Renewable Materials, Vol.7, No.5, pp. 403-413, 2019, DOI:10.32604/jrm.2019.01846

Abstract Despite the great potential of cellulose wood pulp and cellulose nanofibrils as reinforcing filler in thermoplastics, its use is limited due to its tendency to form agglomerates and due to its high hydrophilic character. Here we describe fiberboard composites with high contents of wood pulp or cellulose nanofibrils, and a resin of poly (styrene-methyl-methacrylate-acrylic acid) used as water-based emulsion. Cellulose wood pulp and cellulose nanofibrils were used directly in the form of water suspensions. The method is based on the flocculation of the polymer emulsion followed by agglomeration of a mixture of the polymer emulsion and cellulose suspension, leading to… More >

Edgars Vanags*, Mikelis Kirpluks, Ugis Cabulis and Zuzana Walterova

Journal of Renewable Materials, Vol.6, No.7, pp. 764-771, 2018, DOI:10.7569/JRM.2018.634111

Abstract In this work, free tall oil fatty acids were epoxidized with in-situ generated peroxyacetic acid. Reaction kinetics of epoxidation was investigated by oxirane content and iodine value titrimetric determination, as well as FTIR spectra analysis. A highly functional biobased polyol was synthesized by functionalizing epoxidized tall oil fatty acids with triethanolamine using Montmorillonite K10 as a catalyst. The obtained polyol was analyzed by FTIR and MALDI-TOF MS. The most common chemical and physical characteristics of obtained polyol were determined. More >

Hassen Mohamed Sbihi^1,*, Hamid Shaikh², Lahssen El Blidi², Imed Arbi Nehdi¹, Ubair Abdus Samad², Moufida Romdhani-Younes³, Saud Ibrahim Al-Resayes¹

Journal of Renewable Materials, Vol.6, No.6, pp. 651-661, 2018, DOI:10.7569/JRM.2018.634105

Abstract In this study, different samples of alkyd resins based on Citrullus colocynthis seed oil (CCSO)—which has a high content of linoleic acid—were prepared as a renewable raw material. Short (I), medium (II), and long (III) alkyd resins were synthesized using oil, glycerol, and phthalic anhydride (PA) in different proportions. Prunus mahaleb seed oil (PMSO), which contains conjugated linolenic acid, was blended with CCSO in different proportions to examine the effect of PMSO on the film properties of alkyd resins (IV and V). All synthesized resins were characterized by FTIR and 1H NMR spectroscopic analysis. These resins were also cured by… More >

Kunal Wazarkar, Anagha Sabnis*

Journal of Renewable Materials, Vol.6, No.4, pp. 438-449, 2018, DOI:10.7569/JRM.2017.634159

Abstract The research work presented in this article deals with the synthesis of cardanol-based polyol and its curing with hexabutoxymethyl melamine (HBMM) for application in coatings. Cardanol-based polyol was prepared via thiol-ene click reaction using thioglycerol. Unsaturation present in the long chain of cardanol was successfully utilized to synthesize polyol via thiol-ene coupling. The reaction was carried out between cardanol and thioglycerol in the presence of Irgacure 184 (photoinitiator) and 1,8-Diazabicyclo[5.4.0]undec-7-ene (catalyst) under UV light for 12 h at 80 °C. After completion of the reaction, one mole of thioglycerol was successfully added across the double bond of a fatty chain… More >