Improvement of interlaminar mechanical properties of CFRP laminates using VGCF

In order to improve the interlaminar mechanical properties of CFRP laminates, hybrid CFRP/VGCF laminates have been fabricated by using a newly-developed method, i.e., powder method, where the powder of vapor grown carbon fiber (VGCF) is added at the mid-plane of [0°/0°]₁₄ CFRP laminates. Experimental results of double cantilever beam (DCB) tests indicate the improvement on the interlaminar mechanical properties of Mode-I fracture behavior with much higher critical load P_C and fracture toughness G_IC with VGCF interlayer. Crack propagation and fracture surface have also been observed to interpret this improvement mechanism. Moreover, based on experimental G_IC, numerical simulations using finite element method (FEM) with cohesive elements have been carried out to analyze the delamination propagation. The interlaminar tensile strength of hybrid CFRP/VGCF laminates, which is obtained by matching the numerical load–COD (crack opening displacement) curves to experimental ones, is higher than that of base CFRP laminates.     

Drosophila as an Animal Model for Testing Plant-Based Immunomodulators

Allopathic medicines play a key role in the prevention and treatment of diseases. However, long-term consumption of these medicines may cause serious undesirable effects that harm human health. Plant-based medicines have emerged as alternatives to allopathic medicines because of their rare side effects. They contain several compounds that have the potential to improve health and treat diseases in humans, including their function as immunomodulators to treat immune-related diseases. Thus, the discovery of potent and safe immunomodulators from plants is gaining considerable research interest. Recently, Drosophila has gained prominence as a model organism in evaluating the efficacy of plant and plant-derived substances. Drosophila melanogaster “fruit fly” is a well-known, high-throughput model organism that has been used to study different biological aspects of development and diseases for more than 110 years. Most developmental and cell signaling pathways and 75% of human disease-related genes are conserved between humans and Drosophila. Using Drosophila, one can easily examine the pharmacological effects of plants/plant-derived components by employing a variety of tests in flies, such as survival, anti-inflammatory, antioxidant, and cell death tests. This review focused on D. melanogaster’s potential for identifying immunomodulatory features associated with plants/plant-derived components.     

Effect of natural biomass fillers on the stability,degradability, and elasticity of crop straws liquefied polyols-based polyurethane foams

Oilseed rape straw (OS), rice straw (RS), wheat straw (WS), and corn stover (CS) particles were used to reinforce bio-polyols based polyurethane (PU) foams. The influence of crop straws (XS) fillers on the stability in water, degradability in soil, thermal stability, and elasticity of foams were investigated. The incorporation of OS and CS particles in the PU matrix increased the stability of reinforced foams in water, while the addition of WS and RS particles made foams lower stability in water. PU foams reinforced by XS particles displayed mass reductions up to 53.8% after burying in soil for 250 days. The reinforced foams were more stable under heating but the enhancement of thermal stability trended to disappear after water immersion or soil burying. The reinforced foams showed better elasticity that incorporations of OS and CS made PU foams higher height recovery percentage, while RS and WS made the recovery percentage decline firstly and then enhance during three times compressions. All these four XS particles are suitable to modify bio-based PU foams, especially OS and CS particles appear to be more outstanding in preparing foams with higher stability in water, degradability in soil, thermal stability, and elasticity than RS and WS particles.     

Combustion Mechanism of Glycidyl Azide Polymer

A combustion model of glycidyl azide polymer (GAP) is presented. Linear burning rate and temperature profile measurements of model samples led us to the conclusion that linear burning rate is controlled by N₂ liberation process below the pressure exponent break point (2.3 MPa). Further, scanning electron microscope (SEM) photographs and Fourier transform infrared (FTIR) spectra of quenched samples by rapid depressurization of the combustor show that the N₂ liberation process is strongly limited to the melt layer at the combustion surface and the profile of the heat release rate is probably δ-function like. This fact enables the application of an asymptotic analysis to this phenomenon.