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  • Open Access

    ARTICLE

    Renewable Bis-benzoxazine Monomers from Lignin Derivatives: Synthesis, Characterization and Studies on Curing Behavior

    CHUNYAN LIU*, YUNHE LIU, ZIHAN PAN, QIUTING LI, HAN XU, TAO LIU

    Journal of Polymer Materials, Vol.36, No.1, pp. 87-99, 2019, DOI:10.32381/JPM.2019.36.01.7

    Abstract In this work, a series of novel lignin-based bis-benzoxazine monomers were efficiently synthesized by the reaction of renewable phenols: guaiacol, vanillyl alcohol, eugenol, vanillin with ethylene diamine and paraformaldehyde. The chemical structures of these lignin-based bis-benzoxazine monomers were confirmed by 1H-NMR, 13C-NMR and FTIR, indicating the formation of benzoxazine ring. The obtained bis-benzoxazine monomers were cured via thermal treatment. The curing behavior of these lignin-based bis-benzoxazine monomers were compared and analyzed via differential scanning calorimetry (DSC), showing that Va-e possessed higher ring-opening polymerization activity than G-e, while E-e and V-e had lower curing activity than G-e. More >

  • Open Access

    ARTICLE

    Synthesis and Characterization of New Chromophore 4-2-(2-hydroxy-5-(4 nitrophenyl) diazenyl) benzylidene) hydrazinyl) Benzoic Acid and its use in Chitosan Modification

    KAZIM SHAMIM RIZVI, P.K.DUTTA*

    Journal of Polymer Materials, Vol.36, No.1, pp. 75-85, 2019, DOI:10.32381/JPM.2019.36.01.6

    Abstract The present investigation deals with the preparation of carboxylic acid containing new chromophore : 4-2-(2-hydroxy-5-(4-nitrophenyl) diazenyl) benzylidene) hydrazinyl) benzoic acid and its use for chemical modification of chitosan, e.g., chitosan-acid salt complexes under mild conditions. Optical properties of chitosan acid complexes were evaluated by UV and SHG spectroscopy which showed red shift. Antibacterial activity of prepared chitosan acid complexes showed obvious effect against food pathogenic bacteria. The novel polymer complex was soluble in most of the organic solvents. More >

  • Open Access

    ARTICLE

    Long term diazotrophic cultivation induces phycobiliprotein production in Anabaena variabilis IMU8

    Mohammed Fadhil HADDAD1,2,3, Tugba DAYIOGLU1,2, Barbaros NALBANTOĞLU2, Turgay CAKMAK1,*

    BIOCELL, Vol.43, No.4, pp. 327-333, 2019, DOI:10.32604/biocell.2019.08522

    Abstract Cyanobacteria are considered as a sustainable feedstock for the production of biochemically active compounds such as phycobiliproteins (PBPs). In this study, the impact of nitrogen (N) and phosphorus (P) availability on PBP production of “N-free acclimated” Anabaena variabilis IMU8 was analyzed. Upon isolation and identification, the cyanobacterium has been maintained in N-free BG-11 medium for more than 20 months. For experimentation, the strain was incubated in N-replete, N-depleted, N-P-depleted BG-11 medium. Long-term diazotrophic cultivation of A. variabilis IMU8 resulted in elevated PBP productivity with a limited impact on growth. When compared to N-depleted ones, N supply stimulated More >

  • Open Access

    REVIEW

    Effects of Particle Matters on Plant: A Review

    Lijuan Kong1,2, Haiye Yu1,2, Meichen Chen1,2, Zhaojia Piao1,2, Jingmin Dang1, Yuanyuan Sui1,2,*

    Phyton-International Journal of Experimental Botany, Vol.88, No.4, pp. 367-378, 2019, DOI:10.32604/phyton.2019.09017

    Abstract The particle matter, particularly the suspended particle matter (PM ≤ 2.5) in the air is not only a risk factor for human health, but also affects the survival and physiological features of plants. Plants show advantages in the adsorption of particle matter, while the factors, such as the leaf shape, leaf distribution density and leaf surface microstructure, such as grooves, folds, stomata, flocculent projections, micro-roughness, long fuzz, short pubescence, wax and secretory products, appeared to play an important role determing their absorption capacity. In this paper, the research progress on the capture or adsorption of… More >

  • Open Access

    ARTICLE

    Optimization of Face Recognition System Based on Azure IoT Edge

    Shen Li1, Fang Liu1,*, Jiayue Liang1, Zhenhua Cai1, Zhiyao Liang2

    CMC-Computers, Materials & Continua, Vol.61, No.3, pp. 1377-1389, 2019, DOI:10.32604/cmc.2019.06402

    Abstract With the rapid development of artificial intelligence, face recognition systems are widely used in daily lives. Face recognition applications often need to process large amounts of image data. Maintaining the accuracy and low latency is critical to face recognition systems. After analyzing the two-tier architecture “client-cloud” face recognition systems, it is found that these systems have high latency and network congestion when massive recognition requirements are needed to be responded, and it is very inconvenient and inefficient to deploy and manage relevant applications on the edge of the network. This paper proposes a flexible and… More >

  • Open Access

    ARTICLE

    A Graph-Based Reinforcement Learning Method with Converged State Exploration and Exploitation

    Han Li1, Tianding Chen2, *, Hualiang Teng3, Yingtao Jiang4

    CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.2, pp. 253-274, 2019, DOI:10.31614/cmes.2019.05807

    Abstract In any classical value-based reinforcement learning method, an agent, despite of its continuous interactions with the environment, is yet unable to quickly generate a complete and independent description of the entire environment, leaving the learning method to struggle with a difficult dilemma of choosing between the two tasks, namely exploration and exploitation. This problem becomes more pronounced when the agent has to deal with a dynamic environment, of which the configuration and/or parameters are constantly changing. In this paper, this problem is approached by first mapping a reinforcement learning scheme to a directed graph, and… More >

  • Open Access

    ARTICLE

    In vitro evaluation of native entomopathogenic fungi and neem (Azadiractha indica) extracts on Spodoptera frugiperda

    Hernandez-Trejo A1, B Estrada-Drouaillet1, JA López-Santillán1, C Rios-Velasco2, SE Varela-Fuentes1, R Rodríguez-Herrera3, E Osorio-Hernández1

    Phyton-International Journal of Experimental Botany, Vol.88, No.1, pp. 47-54, 2019, DOI:10.32604/phyton.2019.04611

    Abstract The control of Spodoptera frugiperda is based on synthetic insecticides, so some alternatives are the use of entomopathogenic fungi (EF) and neem extract. The objective of the study was to evaluate in vitro effectiveness of native EF and neem extracts on S. frugiperda larvae. Six EF were identified by DNA sequencing of ITS regions from three EF (Fusarium solani, Metarrhizium robertsii, Nigrospora spherica and Penicillium citrinum). They were evaluated in concentrations of 1 × 10⁸ spores/ mL. In addition, a second bioassay was carried out evaluating only F. solani, M. robertsii and N. sphaerica and… More >

  • Open Access

    ABSTRACT

    Empirical Formulae to Predict Hardness, Hydrogen Diffusion Coefficient and Tensile Properties of Steel HAZ

    Tadashi Kasuya1,*, A. Toshimitsu Yokobori Jr2, Nobuyuki Ishikawa3, Manabu Enoki1, Satoshi Minamoto4

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 120-120, 2019, DOI:10.32604/icces.2019.05227

    Abstract Weld cold cracking is categorized as hydrogen cracking. To assess cold cracking susceptibility of steel HAZ (heat affected zone), it is necessary to estimate local hydrogen content and residual stress at a weld root that are in general numerically calculated by FEM and/or FDM. To conduct numerical calculations, physical and mechanical properties such as diffusion coefficient of hydrogen in steel are necessary. In this work, we have developed empirical formulae to calculate HAZ hardness, hydrogen diffusion coefficient and tensile properties. The present empirical formula of HAZ hardness is expressed using chemical compositions of a welded… More >

  • Open Access

    ARTICLE

    Morphological Characterization of Brazil Nut Tree (Bertholletia excelsa) Fruit Pericarp

    Gustavo P. Petrechen1,4,*, Marcos Arduin3, José D. Ambrósio1,2

    Journal of Renewable Materials, Vol.7, No.7, pp. 683-692, 2019, DOI:10.32604/jrm.2019.04588

    Abstract This article presents the overall morphological structure of the Brazil nut tree (Bertholletia excelsa) fruit pericarp, from macro to nano scale. The acquired knowledge would be used for the development of new applications, like using the materials as fillers for biocomposites, or as a hierarchical architecture model for biomimetics. This research was performed using stereo and light microscopy and conventional and force field emission scanning electron microscopy. The pericarp presents three layers: the exocarp, a dark gray, brittle and fragile outer layer; the mesocarp, a beige, dry, rigid, impermeable and fibrous intermediate layer; and the… More >

  • Open Access

    ARTICLE

    Mapping of the Brazilian Groups Studying Nanocellulose

    Asaph Armando Jacinto*, Márcia Aparecida da Silva Spinacé*

    Journal of Renewable Materials, Vol.7, No.5, pp. 429-440, 2019, DOI:10.32604/jrm.2019.04427

    Abstract The nanocellulose is a material that has gained much attention in the recent years. So, the relevance of Brazil in this field was evaluated concerning the scientific publications in Web of Science. Next, the Brazilian groups were mapped using a bibliometric procedure on these data. Then, more factors were analyzed from them too. They were the sources to extract the nanocellulose in Brazil, the methods to do it, the characterizations to determine its dimensions and the funding agencies of these researches. The results identified 69 Brazilian groups. Besides, the bacterial cellulose was the most common More >

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