Advanced Materials Research Vols. 335-336

Abstract: This study presents an effective methodology for the optimum design of two-component armor. The armor consists of two plates: one is boron carbide ceramic and the other is kevlar/epoxy composites. The effect of the thickness of two plates on the ballistic limit velocities of the armor was investigated by Florence model. A finite element model was created using MSC.DYTRAN to simulate the impact of a rigid projectile on the composite armor. The optimum thickness of the ceramic and composite was obtained by evaluating the ballistic resistance efficiency.

Abstract: 58 fungal elicitors prepared from the endophytic fungi isolated from inner bark of B. platyphylla Suk. were examined to determine their effects on the growth and triterpenoid production in suspension cultures of Betula platyphylla Suk. cells. The results showed that different fungal elicitors could cause diversely stimulating effects. Among the fungal elicitors tested, BE58 stimulated the highest triterpenoids yield with 15.90 mg•L^-1 and 183.72% higher than the control. The experiment also affirmed from mRNA level that triterpenoid was indeed accumulated in suspension culture of birch cells treated by BE58 fungal elicitor. Meantime BE58 was identified as Phomopsis from the morphological and molecular level.

Abstract: The chitosan/palygorskite resins with tannic acid (TA) as template molecules (CPRT) were prepared by emulsion cross-linking technology. Palygorskite (PAL), a kind of natural one-dimensional clay, worked as perfect filler in this study to enhance the adsorptive properties and acid resistance of chitosan resin (CR). The effect of PAL and imprinted molecules on pore parameters of the CPRT, such as swelling degree, porosity, and ratio of weight loss, were investigated, and the effects of the initial pH value of the TA solution, contact time and temperature on adsorption capacity of the CPRT were also discussed. The results revealed that the adsorption process was found to be pH dependant with an optimum activity at pH 8.0. In comparison with CR, the adsorptive ability of CPRT increased from 225 to 410 mg/g, and the ratio of weight loss decreased from 18.8 to 6.2 %. The study of adsorption kinetics and isotherms showed that the sorption processes were better fitted by pseudo-second-order equation and the Langmuir equation, respectively.

Abstract: Bacterial cellulose (BC)/Poly vinyl alcohol (PVA) multilayer composite hydrogels were prepared by freezing and thawing. The mechanical properties of the composite were investigated in this paper with different mass percent of PVA, number of BC layers. Scanning electron microscope (SEM) was used to characterize the fracture characterizations of the composite and the interface structure between BC membrane and PVA hydrogel. It was found that composite hydrogels with 15wt% PVA and 2 layers BC membranes exhibit excellent mechanical properties and wonderful bonding effect of the interface.

Abstract: In this article, the damping mechanism of organic hybrids consisting of Nitrile Butadiene Rubber (NBR) and phenolic oligomer 4-methyl-pheno reaction products of both dicyclopentadiene and isobutylene (MPDI) were investigated by dynamic mechanical analysis (DMA). It was shown that NBR/MPDI blends exhibit only one damping peak, which shifted to higher temperature with the increase of MPDI content, and the maximum of tan δ peak decreased slightly when the ratio of NBR/MPDI was no more than 100/20, and then increased when the ratio rised from 100/20 to 100/80. Fourier transform infrared spectrum (FT-IR) showed that the hydrogen bond were formed between -OH of MPDI and a-H of NBR. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements indicated that MPDI exhibit amorphous features, which was compatible with the blends. These may imply that much more stable damping material with both higher tan δ peak and controllable damping peak position can be achieved.

Abstract: Cement asphalt mortar (CA mortar, or CAM) is a composite material with equal presence of cement and asphalt emulsion and acts as a cushion layer in the structure of slab track. In the hardened matrix, asphalt accounts for about 30 vol. %, rendering the properties of CA mortar susceptible to temperature variation. In the paper, different kinds of emulsified asphalts (A70 emulsified asphalt, A90 emulsified asphalt, SBS modified emulsified asphalt and SBR modified emulsified asphalt) for CA mortar and the compressive strengths of CA mortar under different temperatures (-18°C, 10°C, 25°C, 40°C and 60°C) were studied to reflect its thermal dependence. Results indicate that temperature susceptibility of CA mortar prepared with modified emulsified asphalt is better than which prepared with unmodified emulsified asphalt. SBS modified emulsified asphalt -CAM (viz. CA mortar prepared by SBS modified emulsified asphalt) is alleviated at the whole temperature range, while that of SBR modified emulsified asphalt -CAM is improved primarily at the lower temperature region. As for types of unmodified asphalts, A90 emulsified asphalt -CAM outperforms A70 emulsified asphalt -CAM at lower temperature range.

Abstract: CuO nanocrystal has been successfully synthesized by adopting liquid phase reaction and using cupric nitrate and sodium hydroxide as raw materials. The prepared products are characterized by XRD, FT-IR and TEM. The catalysis of CuO Nanocrystal on KClO₄ is investigated by thermal analysis. The results show that CuO nanocrystal is consisted of the mixture of spherical nanoparticles with an average sizes of 11nm. The catalysis of CuO nanocrystal on KClO₄ thermal decomposition was strong. And it makes thermal decomposition temperature of KClO₄ to decrease 97.7 °C, the decalescence amount also reduced to 79.07 J/g. But the addition of CuO nanocrystal has no effect on the crystal shape transformation of KClO₄.

Abstract: Hazard Analysis & Critical Control Points (HACCP) is the core component of the food safety management system which analyzes and controls biological, chemical, and physical hazards of food at each key point of food chain, namely from raw material production, procurement and handling, to manufacturing, distribution and consumption of the finished product [1]. However, the information of each point of HACCP does not connect. To bridge the gaps among points of food chain, GS1 system needs to be integrated into the HACCP system.

Abstract: In the present study, Ti-6Al-2.5Sn-4Zr-0.7Mo-0.3Si-0.3Y alloy matrix composites reinforced with TiB and TiC were fabricated by combustion-assisted cast utilizing the reaction between titanium and B₄C, graphite. The microstructure, room temperature mechanical properties were presented and discussed. Microstructural analysis of the composites revealed that the prior β grain size as well as the thickness of α colony significantly refined with increasing of volume fraction. At room temperature (RT), tensile strength and elastic modulus increase significantly, while the ductility drops gradually possibly because of the cracking of TiB whiskers and TiC particles.

Abstract: In this study, Al-Si alloy protective coating was deposited on the surface of ZM5 magnesium alloy by cold spray technology. Researchers observed the surface morphology of the coating by SEM, and researched tribological properties of the substrate material and the coating. The results show that, the bonding mechanism of the Al-Si alloy coating and substrate is metallurgical bonding and mechanical interlocking. The abrasion mechanism of Al-Si alloy coating is adhesive wear. The friction coefficient of the coating is higher than magnesium alloy in different friction frequencies. Greater change in friction coefficient is caused by the inhomogeneous phase composition. But the wear track depth of the coating is smaller than magnesium alloy. Wear-resisting property is improved.