Comprehensive study of recycling of thermosetting polymer composites – Driving force, challenges and methods

2021 ◽  
Vol 207 ◽  
pp. 108596
Author(s):  
Shubham Utekar ◽  
Suriya V K ◽  
Neha More ◽  
Adarsh Rao
2017 ◽  
Vol 114 (31) ◽  
pp. 8330-8335 ◽  
Author(s):  
Sean W. Buskirk ◽  
Ryan Emily Peace ◽  
Gregory I. Lang

Beneficial mutations are the driving force of adaptive evolution. In asexual populations, the identification of beneficial alleles is confounded by the presence of genetically linked hitchhiker mutations. Parallel evolution experiments enable the recognition of common targets of selection; yet these targets are inherently enriched for genes of large target size and mutations of large effect. A comprehensive study of individual mutations is necessary to create a realistic picture of the evolutionarily significant spectrum of beneficial mutations. Here we use a bulk-segregant approach to identify the beneficial mutations across 11 lineages of experimentally evolved yeast populations. We report that nearly 80% of detected mutations have no discernible effects on fitness and less than 1% are deleterious. We determine the distribution of driver and hitchhiker mutations in 31 mutational cohorts, groups of mutations that arise synchronously from low frequency and track tightly with one another. Surprisingly, we find that one-third of cohorts lack identifiable driver mutations. In addition, we identify intracohort synergistic epistasis between alleles of hsl7 and kel1, which arose together in a low-frequency lineage.


Author(s):  
Sanjay Remanan ◽  
Sabyasachi Ghosh ◽  
Tushar Kanti Das ◽  
Narayan Chandra Das

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1369 ◽  
Author(s):  
Yueke Ming ◽  
Yugang Duan ◽  
Ben Wang ◽  
Hong Xiao ◽  
Xiaohui Zhang

Recently, 3D printing of fiber-reinforced composites has gained significant research attention. However, commercial utilization is limited by the low fiber content and poor fiber–resin interface. Herein, a novel 3D printing process to fabricate continuous fiber-reinforced thermosetting polymer composites (CFRTPCs) is proposed. In brief, the proposed process is based on the viscosity–temperature characteristics of the thermosetting epoxy resin (E-20). First, the desired 3D printing filament was prepared by impregnating a 3K carbon fiber with a thermosetting matrix at 130 °C. The adhesion and support required during printing were then provided by melting the resin into a viscous state in the heating head and rapidly cooling after pulling out from the printing nozzle. Finally, a powder compression post-curing method was used to accomplish the cross-linking reaction and shape preservation. Furthermore, the 3D-printed CFRTPCs exhibited a tensile strength and tensile modulus of 1476.11 MPa and 100.28 GPa, respectively, a flexural strength and flexural modulus of 858.05 MPa and 71.95 GPa, respectively, and an interlaminar shear strength of 48.75 MPa. Owing to its high performance and low concentration of defects, the proposed printing technique shows promise in further utilization and industrialization of 3D printing for different applications.


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