ChemNet: A Deep Neural Network for Advanced Composites Manufacturing.

Among advanced manufacturing techniques for fiber-reinforced polymer-matrix composites (FRPCs) which are critical for aerospace, marine, automotive, and energy industries, frontal polymerization (FP) has been recently proposed to save orders of magnitude of time and energy. However, the cure kinetics of the matrix phase, usually a thermosetting polymer, brings difficulty to the design and control of the process. Here, we develop a deep learning model, ChemNet, to solve an inverse problem for predicting and optimizing the cure kinetics parameters of the thermosetting FRPCs for a desired fabrication strategy.

Impact of Boundary Heat Losses on Frontal Polymerization.

Considered as a faster and energy-efficient alternative to conventional manufacturing techniques for thermosetting polymers and composites, frontal polymerization (FP) is built on a thermal equilibrium between the heat generated by the exothermic reaction of the resin system and the heat consumed by the advancing front. However, a heat loss to the surrounding may disrupt this thermal equilibrium and slow down and possibly quench the front. This paper investigates the impact of two types of heat loss to the surrounding on the key characteristics (propagation speed and maximum temperature) of the polymerization front: convective heat loss along the boundary of the reaction channel and contact heat loss at channel-tool plate interfaces.

The association between fecal enterotoxigenic B. fragilis with colorectal cancer.

Background: Enterotoxigenic Bacteroides fragilis (ETBF) is an enterotoxin-producing bacterium that possibily has a role in the occurrence and progression of colorectal cancer (CRC) by modulating the mucosal immune response and inducing epithelial cell changes. The aim of this study was to investigate the frequency of ETBF in stool samples of CRC patients and healthy volunteers.

Methods: A total of 60 stool samples from confirmed CRC patients and 60 stool samples from healthy volunteers with no personal or familial history or diagnosis of colorectal disease were collected.

Rapid energy-efficient manufacturing of polymers and composites via frontal polymerization.

Thermoset polymers and composite materials are integral to today's aerospace, automotive, marine and energy industries and will be vital to the next generation of lightweight, energy-efficient structures in these enterprises, owing to their excellent specific stiffness and strength, thermal stability and chemical resistance. The manufacture of high-performance thermoset components requires the monomer to be cured at high temperatures (around 180 °C) for several hours, under a combined external pressure and internal vacuum . Curing is generally accomplished using large autoclaves or ovens that scale in size with the component.

Frontal Polymerization of Dicyclopentadiene: A Numerical Study.

As frontal polymerization is being considered as a faster and more energy efficient manufacturing technique for polymer-matrix fiber-reinforced composites, we perform a finite-element-based numerical study of the initiation and propagation of a polymerization front in dicyclopentadiene (DCPD). The transient thermochemical simulations are complemented by an analytical study of the steady-state propagation of the polymerization front, allowing to draw a direct link between the cure kinetics model and the key characteristics of the front, i.e.