Applied Mechanics and Materials Vols. 713-715

Abstract: The aim of this study was to determine the efficacy of several alternative postharvest treatments to sulfur dioxide (SO₂) in storage quality during cold storage of red grape.The three kinds of treatment were 0μL/L (CK),3000μL/L(TR1),5000μL/L(TR2).The results showed that SO₂ damagement effected on physiological metabolic and physiological quality of grapes significantly.It can inhibit the rise in pH of grapes,harm the integrity of cell membranes,increase conductivity and malondialdehyde content and stimulate the activity of polyphenol oxidase. But right amont of SO₂ had a positive effect on strage and preservation of grape.

Abstract: In this work, poly (vinylidene fluoride)-graft-poly (N-isopropylacrylamide) (PVDF-g-PNIPAAm) thermo-sensitive polymer and poly (NIPAAm-co-AAc-L-Phe) chiral micro-gels were synthesized firstly. A chiral thermo-sensitive membrane for phenylalanine separation of the racemic mixture was prepared by phase inversion method with the blend of poly (NIPAAm-co-AAc-L-Phe) and PVDF-g-PNIPAAm. The blend membrane formation mechanism of the casting solutions in water bath thermodynamics at different temperatures and the process of membrane formation were investigated via cloud point determination and ultrasonic time-domain reflectometry (UTDR). The results showed that the inversion between hydrophilicity and hydrophobicity of PNIPAAm contributed to the membrane formation process. From the time needed in membrane forming recorded by ultrasonic signal spectra, it can be found that the speed for solidification was increased when the coagulation-bath temperature was higher than 30°C.

Abstract: The interfacial reaction and growth of intermetallic compounds (IMCs) between the eutectic Sn-0.7 wt.% Cu solder and Cu substrate during soldering process were investigated experimentally. The Sn-0.7Cu/Cu couples were fabricated with soldering temperature varied at four levels of 300, 340 and 360°C. Microstructural analysis is conducted to analyze the IMCs thickness and morphology using scanning electron microscope. Two intermetallic phases were observed during soldering at the interface: η-phase (Cu₆Sn₅) and ε-phase (Cu₃Sn) IMC layers, except for the solder joints which were fabricated at low temperature. The thickness of the η and ε IMC phases increase with increasing the soldering temperature. It’s found that the increase in total IMC layer thickness obeys a linear relationship with soldering temperature. And the relationship between X and T was given as X = 0.0866×T – 22.5 by means of linear fitting method.

Abstract: The stay cables are usually subjected to continuous erosion from the environment in their service period. The protective layer on the cable wire is an important barrier for the cable corrosion resistance. Therefore, the durability of the cable depends greatly on the proper selection of the protective layer, which makes a big difference comparing with the bare cable wires. This paper studies on the corrosion performance of 6 common kinds of cable steels under the same corrosion environment with electrochemical test methods. The conclusions can be used as a reference to selecting a proper kind of cable wires during the bridge construction.

Abstract: Band inversion mechanisms of half Heusler compouds XMBi (X=Sc, Y, Lu, La, M=Pd, Pt) is investigated under different conditions, based on first-principles calculations with generalized gradient approximation approach. The results shown that Spin-orbit coupling, however, is not the leading cause but an account can add further fuel to the band inversion. The present finding provides an effective scheme to search for topologically nontrivial materials.

Abstract: The etched stainless steel powder was prepared and explored as sorbent material for solid-phase extraction coupled with high-performance liquid chromatography (HPLC) for determination of trace polycyclic aromatic hydrocarbons (PAHs) in environmental matrices. The etched stainless steel powder was shown to be promising for solid-phase extraction of PAHs in environmental samples with subsequent HPLC separation and UV detection. This paper explored different factors that affected the adsorption efficiency of etched stainless steel powder, including the etched time of stainless steel powder, the mass of sorbent, and the volume of water sample, and so on. In the optimum conditions, nine kinds of PAHs, including trace naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzanthracene and benzopyrene, were extracted by etched stainless powder and the extraction efficiency is satisfactory.

Abstract: Experimental research on the treatment of printing and dyeing wastewater has been carried out. The method of ultrasonic combined Fenton has been used.Separately by using ultrasonic and Fenton oxidation method to treat printing and dyeing wastewater, the hydrogen peroxide dosage, FeSO₄•7H₂O dosage, shaking time, pH value, ultrasonic time, ultrasonic power and other factors are investigated.The COD and chromaticity removal effect of printing and dyeing wastewater are calculated. The experimental results show that the above factors have a certain impact on the treatment effect. Based on these results, the orthogonal test method is used in this experiment, the optimal conditions of ultrasound combined with Fenton reagent for dealing printing and dyeing wastewater has been determined.The orthogonal experimental results show that the optimal reaction conditions of orthogonal test are below:pH value is 3, the best time for the experiment is 1.5h, hydrogen peroxide dosage is 5mL, seven water ferrous sulfate dosage is 0.7grams, ultrasonic power is 142.5W. Experiments are conducted in accordance with the best reaction conditions. On the optimal process conditions, the removal rate of COD reaches 94.6% and the chroma removal rate reaches 87.5%. The effect of using ultrasonic combined with Fenton reagent to treat printing and dyeing wastewater is better than the use of single method.

Abstract: There is growing interest in cellulose nanowhiskers from renewable sources for several industrial applications. In this work, sisal cellulose nanowhiskers (SCNW) are produced from sisal fiber by the combinations of acid hydrolysis and dialysis treatment. The structure of SCNW is characterized by Fourier transform infrared spectroscopy (FTIR), the morphology of SCNW is observed using field emission scanning electron microscopy (FESEM), and the thermal properties of SCNW is investigated by differential thermogravimetric analysis (DTG). The FTIR study displays that the chemical structures of SCNW are consistent with those of cellulose, indicating the removal of most of hemicelluloses during the acid hydrolysis process. The DTG result suggests the initial decomposition temperature of SCNW is 280 °C and the terminal decomposition temperature is 356 °C, the residual rate is 10% or so, indicating favorable thermal performance. The SEM results show that the sisal cellulose microcrystals exhibit an average length of 50 μm and a diameter of 5~10 μm, and SCNW displays a diameter of 5~60 nm and a length of several micrometers, revealing that the size of SCNW is much smaller than that of cellulose microcrystal. All above results illustrate that SCNW has a great promise for many potential applications, such as pharmaceutical, liquid filtration, catalysts, bio-nanocomposites, and tissue engineering scaffolds.

Abstract: Fe (Ш) can be reduced to Fe (II) by hydrosulfuryl (-SH) in acetylcysteine molecule,and then using tiron as chromogenic reagent of Fe (Ш),and the content of acetylcysteine is determinated indirectly through determinating the surplus content of Fe (Ш) in the system.An accurate fast spectrophotometric method for the determination of acetylcysteine by discoloration spectrophotometry using Fe (Ш)-tiron system has been established.This proposed method had been successfully applied to determinate of acetylcysteine in real pharmaceutical.

Abstract: Waste oil as raw material, study the possibility of waste oil steam cracking to produce light olefins, and focus on pyrolysis temperature on liquid product distribution law. The experimental results show that light olefins yield increases with the pyrolysis temperature; Waste oil first ester fault occurs for a variety of long-chain fatty acids. As temperature increases, the various fatty acids gradually pyrolysis of a variety of small molecules, and its acid value decreased, aromatic compounds in liquid products gradually increased, and fatty acid content decreased. Study the liquid product with temperature variation can take the effective use of waste oil, waste oil for a partial substitute for naphtha to supple the steam cracking feeds.