Advanced Materials Research Vols. 476-478

Abstract: The objective of this research is to predict yarn tensile strength. The model of predicting yarn tensile strength is built based on RBF neural network. The RBF neural networks are trained with HVI test results of cotton and USTER TENSOJET 5-S400 test results of yarn. The results show prediction models based on RBF neural network are very precise and efficient.

Abstract: We report a first-principles investigation on BN dopped monolayer graphene sheet and examined the electronic band structure and band gaps in equilibrium state and under strain. The obtained results reveal that the doping of B-N pairs on the hexagonal sheet can open the gap at the Dirac-like point. With heavy doping and more B-N bonds the energy bad gap is found to be larger. Upon tensile deformation, the dopped BCN monolayer sheet represents a strong anisotropic stress-strain relation. Detailed strain-gap relation investigation reveals that the energy band gap presents desperate variation trends for strain applied along and direction. Versatile band-gap modulation schemes can then be obtained through direction-dependent strain engineering of the BCN nanosheet..

Abstract: Nanostructured Fe25Al57.5Ni17.5intermetallics was prepared directly by mechanical alloying (MA) in a high-energy planetary ball-mill. The phase transformations and structural changes occurring in the studied material during mechanical alloying were investigated by X-ray diffraction (XRD). Thermal behavior of the milled powders was examined by differential thermal analysis (DTA). Disordered Al(Fe,Ni) solid solution was formed at the early stage. After 50 h of milling, Al(Fe,Ni) solid solution transformed into Al3Ni2，AlFe3，AlFe0.23Ni0.77 phase. The power annealed at temperature 500 results in forming of intermetallics AlFe3 and FeNi3 after 5h milling. The nanocrystalline intermetallic compound was obtained after 500h milling.

Abstract: Nanoscale lanthanum cobaltite with perovskite-type was successfully synthesized by microwave irradiation directly and was characterized by XRD, SEM, XPS and BET analysis. The results show that the size of particle was 18 nm averagely, the surface area to be 31.0 m² g⁻¹. The electrochemical properties were studied by cyclic voltammetry and steady state polarization. The cyclic voltammogram between 0 and 0.55 V exhibited two pairs of redox peaks prior to the onset of O₂ evolution in 1 mol dm⁻³ KOH. The Tafel slope and the reaction order with respect to concentration of OH⁻ were found to be 60 mV decade⁻¹ and ca. 1, respectively.

Abstract: The adsorption kinetics of strong alkaline anion exchange fiber for Cr (VI) from aqueous solutions was investigated. The adsorption was a fast process. Kinetics data for adsorption of Cr (VI) from aqueous solutions were in good agreement with the pseudo-second rate equation within an initial concentration range of 50-500 mgL-1. Both the equilibrium capacity and initial adsorption rate increased with an increase in Cr (VI) initial concentration. The adsorption process had combined control by chemisorption and physisorption, including film diffusion and intra-particle diffusion.

Abstract: The swelling behaviors of SAF in distilled water and various saline solutions were investigated and the absorption mechanism of SAF was discussed. Emphasises were laid on the effects of swelling time, saline solutions as well as the pH values of solutions on water absorbency of SAF. Results showed that water absorbency of SAF was significantly influenced by ion concentration and ionic valence of saline solutions as well as the pH values of solutions, but it was less affected by swelling time after reaching swelling equilibrium. The absorption mechanism of SAF is consistent with Flory’s theory of network and the osmotic pressure difference between SAF and the external solution is the motive force for swelling of SAF.

Abstract: The concept of energy harvesting works towards developing self-powered devices that do not require replaceable power supplies. Energy scavenging devices are designed to capture the ambient energy surrounding the electronics and convert it into usable electrical energy. A number of sources of harvestable ambient energy exist, including waste heat, vibration, electromagnetic waves, wind, flowing water, and solar energy. While each of these sources of energy can be effectively used to power remote sensors, the structural and biological communities have placed an emphasis on scavenging vibrational energy with ferroelectric materials. Ferroelectric materials have a crystalline structure that provide a unique ability to convert an applied electrical potential into a mechanical strain or vice versa. Based on the properties of the material, this paper investigates the technique of power harvesting and storage.

Abstract: As “Queen of Fibers”, silk is very popular due to its favorable properties. However, unfavorable antibacterial ability has limited the application of silk. In this paper, therefore, the antibacterial treatments containing both silver and chitosan for silk fabric were conducted. X-ray diffraction (XRD), Fourier transform infrared (FTIR), tensile properties and antibacterial ability tests were carried out to characterize the silk fabric containing chitosan and silver. The results showed that chitosan and silver treatment did not destroy the crystalline structure and molecule structure of silk fabric, however, greatly changed the tensile properties and antibacterial ability, i.e. after treatment, the breaking force decreased while elongation at break increased. Especially, the antibacterial ability of silk was greatly improved due to dual effect of chitosan and silver.

Abstract: A 3D two-phase flow computational fluid dynamics (CFD) model containing gas mal-distribution is developed in the Eulerian framework to predict the hydraulics of a dividing wall sieve tray. Variable and position dependent gas superficial velocity is used in the calculation. Using water-air system, simulations of flow patterns and hydraulics of a commercial- scale 1.2m diameter sieve tray are carried out using this model to testify its precision. Then, the same simulations of a dividing wall sieve tray with equal diameter are carried out. The results show that there are two backflow regions on a dividing wall tray, one is in the segmental area, and the other is in the region nearby junction of dividing wall and outlet weir. In the segmental area of trays with equal diameter, the area of backflow region of dividing wall trays is basically equal to that of conventional trays.

Abstract: Ionic liquid containing L-alanine cations and hydrogen sulfate was synthesized using L-alanine and sulfuric acid as materials. Fourier Transform Infrared Specctrometer was used to verify the final product. The results showed that the objective product was developed successfully. General properties of the final product were detected. The results showed that strong acidity, large viscosity, soluble in polar solvents and insoluble in nonpolar solvents were the product’s properties which were suitable for liquefying. The liquefaction rate of ionic liquid on paper was studied. Study the optimum liquefaction condition using the method of orthogonal experiment design. By stirring at 80°C for 3 hours using ionic liquid with the concentration of 100%, liquefaction rate of ionic liquid on paper was high.