Ting Zhang, Yifei Wang, Xinxin Jin, Zhiwen Gu, Xiaoliang Zhang, Bin He^*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.3, pp. 2267-2285, 2023, DOI:10.32604/cmes.2023.023229

Abstract Auto-grading, as an instruction tool, could reduce teachers’ workload, provide students with instant feedback and support highly personalized learning. Therefore, this topic attracts considerable attentions from researchers recently. To realize the automatic grading of handwritten chemistry assignments, the problem of chemical notations recognition should be solved first. The recent handwritten chemical notations recognition solutions belonging to the end-to-end trainable category suffered from the problem of lacking the accurate alignment information between the input and output. They serve the aim of reading notations into electrical devices to better prepare relevant e-documents instead of auto-grading handwritten assignments. To tackle this limitation to… More >

Qiang Xiao^1,2, Yanjun Cao^1,2, Hailu Tan^1,2, Qiaoling Feng^1,2, Xinyue Gu^1,2, Jianhua Lyu^1,2, Hui Xiao^1,2, Ming Chen^1,2,*, Yuzhu Chen^1,2,*

Journal of Renewable Materials, Vol.11, No.2, pp. 1003-1016, 2023, DOI:10.32604/jrm.2022.023621

Abstract In this study, different molar of methylolureas (MMU) were used to improve the properties and drying speed of the raw lacquer (RL). The drying time, gloss, pencil hardness and impact resistance of the lacquer film were tested. The thermal behaviors and chemical structures of the lacquer membrane were also discussed by thermal gravimetric analysis (TGA), fourier infrared spectrometer (FT-IR) and nuclear magnetic resonance (NMR) analysis, respectively. The results demonstrated that lower molar ratio MMU can significantly improve the properties of lacquer. The TGA analysis showed that the modified lacquer had high thermal stability than that of the control. The FT-IR… More > Graphic Abstract

L. Poussard^1,*, A. Mecheri¹, J. Mariage¹, I. Barakat¹, L. Bonnaud¹, J.-M. Raquez^1,2, P. Dubois^1,2

Journal of Renewable Materials, Vol.2, No.1, pp. 13-22, 2014, DOI:10.7569/JRM.2013.634132

Abstract Biobased oligo(butylene succinate)-based thermoplastic polyurethanes (TPUs) were prepared following a twostep polymerization process: condensation of succinic acid and butanediol and the chain extension of resulting hydroxyl-terminated butylene succinate oligomers (OBS) in the presence of butanediol as chain extender and isophorone diisocyanate (IPDI) as coupling agent. Mechanical and thermal properties of the elaborated TPUs were evaluated in terms of hard segment and compared with those of commercial polybutylene succinate (PBS), Bionolle 1001. Whatever the compositions, the ultimate tensile properties of OBS-based TPUs and Bionolle 1001 were found to exhibit similar values (ε_r ≈ 400%, σ_r ≈ 40 MPa), which can be… More >

D. Ahila Jeyanthi^*, T. M. Selvarajan

Intelligent Automation & Soft Computing, Vol.33, No.1, pp. 669-680, 2022, DOI:10.32604/iasc.2022.022187

Abstract The molecular structures are modelled as graphs which are called the molecular graphs. In these graphs, each vertex represents an atom and each edge denotes covalent bond between atoms. It is shown that the topological indices defined on the molecular graphs can reflect the chemical characteristics of chemical compounds and drugs. A large number of previous drug experiments revealed that there are strong inherent connections between the drug’s molecular structures and the bio-medical and pharmacology characteristics. The forgotten topological index is introduced to be applied into chemical compound and drug molecular structures, which is quite helpful for medical and pharmaceutical… More >

Yuan Zhang¹, Ping Li¹, Yiqiang Wu^1,2, Guangming Yuan^1,2, Xianjun Li^1,2, Yingfeng Zuo^1,2,*

Journal of Renewable Materials, Vol.8, No.11, pp. 1473-1488, 2020, DOI:10.32604/jrm.2020.011788

Abstract The Chinese fir wood was impregnated using a cyclic increasingpressure method (CIPM) with phenolic prepolymers as the impregnating modifier. Unmodified Chinese fir and progressive increasing-pressure method (PIPM) impregnated Chinese fir were used as reference samples and were compared and analyzed. The product’s chemical structure, internal morphology, crystal structure, and heat resistance were characterized. The transversal and longitudinal sections showed better filling effects, so that it bore greater external loading and reduced the water storage space. CIPM infused more phenolic prepolymer into the Chinese fir. Not only producing more physical filling but also forming more hydrogen bond associations and chemical bond… More >

Marcin Włoch, Janusz Datta^*

Journal of Renewable Materials, Vol.4, No.1, pp. 72-77, 2016, DOI:10.7569/JRM.2015.634130

Abstract Modern polymer science and technology is focused on the development of partial or fully green polymers. This focus is related to green chemistry trends, which propose using natural and renewable resources as monomers in the synthesis of polymers. In this study, biobased diamine was used as a chain extender of ester-urethane prepolymer. Obtained poly(ester-urethane-urea) contains 16 wt% of biobased diamine. There is mention of an amine curing agent that is an amine derivative of dimerized fatty acids (obtained from vegetable oils). Application of two chain extenders, i.e., 1,4-butanediol and biobased diamine (applied separately or in mixture), with different molecular weights… More >