scholarly journals Thermal, mechanical and environmental degradation characteristics of polyhydroxybutyrate-co-valerate reinforced with cellulose fibers

2021 ◽  
Vol 5 (1) ◽  
pp. 3-9
Author(s):  
Ana Maria Coulon Grisa ◽  
Tiago Cristofer Aguzzoli Colombo ◽  
Ademir José Zattera ◽  
Rosmary Nichele Brandalise
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).


2019 ◽  
Vol 139 (2) ◽  
pp. 130-135
Author(s):  
Masanobu Yoshida ◽  
Yoshinori Konishi ◽  
Masamichi Kato

MRS Advances ◽  
2020 ◽  
Vol 5 (52-53) ◽  
pp. 2669-2678
Author(s):  
Jeovani González P. ◽  
Ramiro Escudero G

AbstractDeinking of recycled office (MOW) paper was carried out by using a flotation column and adding separately sodium hydroxide, and the enzyme Cellulase Thricodema Sp., as defibrillators.The de-inked cellulose fibers were characterized according to the standards of the paper industry, to compare the efficiency of the deinking of each chemical reagent used to hydrolyze the fibers and defibrillate them.The computational simulation of the molecular coupling between the enzyme and cellulose was performed, to establish the enzyme-cellulose molecular complex and then to identify the principal amino-acids of endo-β-1,4-D-glucanase in this molecular link, which are responsible for the hydrolysis of the cellulose.Experimental results show the feasibility to replace sodium hydroxide with the enzyme Cellulase Thricodema Sp., by obtaining deinked cellulose with similar optical and physical properties.The use of the enzyme instead of sodium hydroxide avoids the contamination of the residual water; in addition to that, the column is operated more easily, taking into consideration that the pH of the system goes from alkaline to neutral.


2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Adiqa Kiani ◽  
Ejaz Ullah ◽  
Khair Muhammad

The main objective of this study is to investigate the impact of poverty, globalization, and environmental degradation on economic growth in the selected SAARC countries. This study is employed panel Autoregressive Distributive Lag (ARDL) technique for empirical analysis using selected SAARC regions including India, Pakistan, Bangladesh, Nepal and Sri Lanka over the period of 1980 to 2018. Globalization impacts economic growth positively and significantly.  In addition to this the significant negative relationship is found between population and economic growth. The results show that poverty is positively related with environmental degradation. Furthermore, the results indicate that globalization is positively and significantly associated with environmental degradation in the SAARC region. Finally, the results show that urbanization is positive and significantly associated with environmental degradation, which could be the serious concerns for the policy makers to control.


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