Advanced Materials Research Vols. 915-916

Abstract: Isocyanate-terminated prepolymer was prepared by reaction of polyether polyols with toluene diisocynate and was modified by adding CaO, hydroxyl silicone oil and hexamethylene diisocyanate, then solvent-free heavy-duty PU coating was got. The curing process of coating was studied by infrared spectrum. Physical, chemical and electrochemical properties of the coating were tested. The results showed that the coating could finish curing in 20 h at room temperature and its adhesion on the substrate of rusted carbon steel was 11.22 MPa. There was no rust change when the salt fog resistance reached 2200 h, the open-circuit potential electrode of coating showed the anticorrosion mechanism of it was given priority to shielding, linear polarization resistance of it exceeded 220 kΩcm². All the above showed that solvent-free heavy-duty polyurethane coating had excellent anti-corrosion performance.

Abstract: In order to assemble titania nanotubes arrays (TNTs) with better performance in solar cells application, hierarchical voltage-reduction was employed to reduce the thickness of barrier layer and acquire freestanding films simultaneously. Study of intratubular microenvironment and TiO₂/Ti interface indicated that it might be H⁺ generated in anodizing process permeating into the Ti substrate that resulted in peeling off the whole tube layers. Our findings provide a promising way to fabricate freestanding TNTs membranes just by tailoring the applied voltage.

Abstract: This letter reports the preparation of Ni doped CuAlO₂ nanaocrystalline films on sapphire substrates by sol-gel processing and subsequent thermal treatment in vacuum. The crystalline phase in the films was identified to be the delafossite structure by X-ray diffraction. Field-emission scanning electron microscope (FESEM) shows the quasi-cubic shape architecture of the as-prepared CuAlO₂ nanaocrystalline films. Upon increasing the band gaps of Ni-doped CuAlO₂ nanaocrystalline films increased due to the Burstein-Moss shift. The influence of different Ni doped concentration on absorption spectrum and magnetic properties of CuAlO₂ films was discussed.

Abstract: Ultra-thin films of SiO₂ (nominally 2, 4, 6, 8 and 10nm thick) on silicon, prepared by thermal oxidation, were investigated using x-ray photoelectron spectroscopy (XPS). The thickness of these thin films was obtained from a measurement of the photoelectron intensities originating from the substrate and the oxide layers by applying an appropriate quantitative model. The uncertainty budget of that thickness measurement method is given. The effective attenuation lengths or the corresponding electron inelastic mean free paths are of the most importance in the contribution of the uncertainties. For the SiO₂ ultra-thin film with the nominal thickness of 2nm, it could generate 20% of the uncertainty.

Abstract: Cu₂ZnSnS₄ thin films have been synthesized through sulfurization of co-electrodeposited Cu-Zn-Sn metallic precursor. The obtained metallic precursor shows homogeneous surface. Combination of X-ray diffraction, energy dispersive X-Ray spectroscopy and Raman spectroscopy results shows that kesterite structure of Cu₂ZnSnS₄ is formed, demonstrating that co-electrodeposition-sulfurization is a viable process for the synthesis of Cu₂ZnSnS₄ film.

Abstract: The advantages of AlInGaN as a blocking layer on the influence of violet InGaN laser diodes have been simulated, these results showed that the temperature characteristic (T₀) of the violet InGaN laser diodes with AlInGaN blocking layer is lower than the T₀ of the violet InGaN laser diodes with AlGaN blocking layer. These phenomenons are due to the improvement of electronics and holes distribution in the quantum wells with using AlInGaN blocking layer. Simulation results also showed that most optical characteristics of the violet InGaN laser diodes can be enhanced by using the AlInGaN blocking layer instead of the AlGaN blocking layer. The lower threshold current, carrier density, threshold gain and higher output power, slop efficiency of the violet InGaN laser diodes with the AlInGaN blocking layer have been obtained.

Abstract: In this paper, failure analysis was conducted to investigate the root cause of Ti/Ni/Ag film peeling from silicon wafer surface. SEM and Edax analysis revealed that peeling was found at Ti/Si interface, and no contamination elements, such as C, H, O, were existed. VK Analyzer was used to measure the surface roughness, and the results revealed that the peeling failure was due to the low surface roughness resulted from excessive polishing after wafer back grinding process. Experiments for changing rabbling polishing method for bubbling polishing one were done expecting to realize high uniformity of surface roughness, and the results showed that roughness uniformity was greatly improved, and no peeling metal was left on the blue tape.

Abstract: This paper assesses the Neo-Hookean material parameters pertaining to deformation behaviour of hyperelastic material by means of numerical analysis. A mathematical model relating stress and stretch is derived based on Neo-Hookeans strain energy function to evaluate the contribution of the material constant, C₁, in the constitutive equation by varying its value. A systematic parametric study was constructed and for that purpose, a Matlab programme was developed for execution. The results show that the parameter (C₁) is significant in describing material properties behaviour. The results and findings of the current study further enhances the understanding of Neo-Hookean model and hyperelastic materials behaviour. The ultimate future aim of this study is to come up with an alternative constitutive equation that may describe skin behaviour accurately. This study is novel as no similar parametric study on Neo-Hookean model has been reported before.

Abstract: The skin, which acts as a protector of the body from potentially harmful external environment is a multi-layered tissue that exhibits complex mechanical behaviour. The aim of this paper is to review available studies of human skin using experimental and numerical methods in determining the mechanical properties of skin. Mechanical properties of skin are vital to the certain industries such as surgical, cosmetics, forensic science and etc., where skin study currently leads to the development of an ultimate skin-like substitute that contains anatomy and physiology characteristics. A number of research papers and journals related to skin were revised and currently findings show that available information in regard to skin biomechanical properties is limited and the actual skin behavior is not comprehensively examined. Nevertheless, further in-depth research is required to develop appropriate techniques in estimating the skin properties which are valuable to the development of biomechanics study of skin.

Abstract: Effects of different methods of gas package on Steamed stuffed bun at room temperature in its shelf life were investigated. The Steamed stuffed bun were packaged under air, N₂ ,CO₂,or O₂, respectively, and then stored 45 days at 25°Cafter the high temperature sterilization. After the sterilization and during storage, the changes of Colorimetric, TPA , and Total viable count were determined. The results showed that carbon dioxide packaging can fully maintain the colorimetric in the high-temperature sterilization. Combining the results of the TPA and other results, carbon dioxide packaging has a better elasticity and chewiness. The package in carbon dioxide could improve the quality of steamed stuffed bun.