Performance comparison of resin-infused thermoplastic and thermoset 3D fabric composites under impact loading

In this paper, the impact performance of a novel resin-infused acrylic thermoplastic matrix-based 3D glass fabric composite (3D-FRC) has been evaluated and compared with thermoset based 3D-FRC under single as well as recurring strike low velocity impact (LVI) events. The single impact tests revealed that the thermoplastic-based 3D-FRC exhibits up to 45% reduced damage area and can have up to 20% higher impact load-bearing capacity (peak force). The damage mode characterization showed that damage transition energy required for micro to macro damage transition is 27% higher, and back face damage extension is up to 3 times less for thermoplastic-based 3D-FRC. Meanwhile, the recurring strike impact test highlights that the thermoplastic-based 3D-FRC experiences a 50% less damaged area, better structural integrity, and survived more strikes. The comparison of single and repeated LVI tests have also allowed us to present a design criterion for estimating the safe number of repeated LVI events for a given impact energy. The superior impact resistance of thermoplastic-based 3D-FRC is attributed to their higher interlaminar fracture toughness, a tougher fiber-matrix interface, matrix ductility, and unique failure mechanism of yarn straining, which is not present in thermoset composites.The authors would like to acknowledge the financial support provided by Universiti Teknologi PETRONAS (grant number 015LC0-197). The authors would also like to acknowledge the support of Dr. Mohamed Thariq Bin Hameed Sultan from Universiti Putra Malaysia in providing the facility to conduct impact tests at their facility. The authors are grateful to Barsotti Robert from Arkema in providing Elium resin for this research work

The B73 Maize Genome: Complexity, Diversity, and Dynamics

We report an improved draft nucleotide sequence of the 2.3-gigabase genome of maize, an important crop plant and model for biological research. Over 32,000 genes were predicted, of which 99.8% were placed on reference chromosomes. Nearly 85% of the genome is composed of hundreds of families of transposable elements, dispersed nonuniformly across the genome. These were responsible for the capture and amplification of numerous gene fragments and affect the composition, sizes, and positions of centromeres. We also report on the correlation of methylation-poor regions with Mu transposon insertions and recombination, and copy number variants with insertions and/or deletions, as well as how uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. These analyses inform and set the stage for further investigations to improve our understanding of the domestication and agricultural improvements of maize