Applied Mechanics and Materials Vol. 470

Abstract: A novel Ga complex (NH₄)Ga(C₇H₃NO₄)₂ has been synthesized from a solution reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Ga atom is six-coordinated by two N atoms and four O atoms from two 2,6-pyridine dicarboxylic acid anions. The crystal packing is stabilized by O-H...N hydrogen bonding interactions.

Abstract: Compacted vermicular (CV) graphitization cast iron is the name given to graphitization cast iron where the shape of the graphite looks like a vermicular. Castability and the thermal conductivity of CV graphitization cast iron is similar to those of Grey iron, while the strength of CV graphitization cast iron is similar to that of ductile iron. The thin film of diamond-like carbon (DLC) is one of the amorphous carbon thin films. It has various characteristics which are similar to those of diamond, such as high hardness, lubricity, abrasion resistance, chemical stability, electrical insulating properties and optical transparency. In this study, wear characteristics of Graphite Compacted Vermicular (GCV) material were investigated in accordance with changes in DLC coating time. The obtained results are as follows: the microstructure of GCV340 showed complex tissue with eccentric graphite and spherical graphite. The friction coefficient shows under 0.2 in all specimens. After enduring the wear test until 2000 m, the coating layer of the DLC coating specimen of 90 minute hardly showed any damage. It had only partial damage after taking the wear test until 2000 m. The friction coefficient was also the lowest.

Abstract: The adsorption of cefradine was carried out using biological adsorbents of powder and carbon prepared from orange peels, an agriculture by-product. The equilibrium was easily reached in less than 10 minutes, with adsorption rates of more than 98%. Cefradine showed a firm combination to the adsorbent, which could hardly be damaged or affected by pH values. After equilibrium was reached within 1 h, no desorption behavior was observed in the next 30 minutes. The adsorption process could be well fitted thermodynamically to both Freundlich and Langmuir equations. Similar results could also be obtained using ashes of orange peel, as well as carbon prepared from pistachio and peanut hull, indicating an attractive option to treat industrial wastewater.

Abstract: In hot rolling process of 2205 duplex stainless steel, it was found that bright line defects are mainly located at where is about distance of 200 mm from two sides of hot rolled plate. The forming reason of bright line defects is studied by means of metallographic microscope, scanning electron microscope (SEM) combined with energy dispersive spectrometer (EDS). It is concluded that the formation of bright line defects has associated with sticking and that the temperature reduction on the edge of hot rolling plate causes a high percentage of austenite phase which is network structure. In order to prevent or avoid the happening of the sticking phenomenon, it is necessary to uniformly distribute the oxide on the strip surface by controlled rolling process.

Abstract: Ozonation of the ubiquitous and poorly biodegradable humic acid in aquatic system was conducted in the presence of activated carbon with the aim of catalyst. The optimum operating parameters deduced from this study was GAC amount of 16.5 v/v% (GAC column volume per reactor volume) in the humic acid solution of initial pH 9. DOC removal rate in Ozone/GAC process was higher than the sum of Ozone alone and GAC adsorption process. Formaldehyde formation in Ozone/GAC process was less than in Ozone alone and GAC adsorption process. The part of molecular size distribution under 10 k Dalton were increased in the Ozone/GAC process.

Abstract: In this paper, we firstly treated the hemp fiber with alkali solution, followed by chemical modification with silane agents: 3-(Trimethoxysilyl) propyl methacrylate (MPS), N-[3-(Trimethoxysilyl) propyaniline (PAPS) and (3-Aminopropyl) triethoxysilane (APS), respectively. These treated fibers were then blended with polypropylene (PP). SEM morphology and FT-IR spectra confirmed the successful modifications of MPS, PAPS and APS with hemp fiber. The tensile tests results showed that APS improved the mechanical properties of composite, due to the amino of APS could react with maleic anhydride forming amide covalent bond which is benefit in the stress transferring from PP matrix to fiber. In contrast, since the incompatibility of aniline with propylene, PAPS modification decreased the fracture stress composites. The existences of ester and vinyl groups in MPS contributed to the increase of composite fracture strain caused by chain slips.

Abstract: 2219 aluminum alloy reinforced with 10wt. % TiB₂ particulate was fabricated through mixed-salts method. The damping capacity and dynamic Yongs modulus was investigated. The damping capacity and dynamic Yongs modulus of 10wt. % TiB₂/2219 is higher than that of the matrix alloy.The improved damping capacity is due to dislocation damping at low temperature, and grain boundary damping and interface damping at high temperature.

Abstract: Natural graphite, carbon fiber and copper powder as fillers are incorporated into phenolic resin to fabricate conductive polymer composites by hot compression moulding. The effects of the preparing method and mould temperature on the density, electrical conductivity and hardness of composites are investigated. It is found that the density, electrical conductivity and hardness of composites increase as mould temperature increase from 150 °C to 180 °C. Up to 200 °C, the hardness of composite shows a large decrease. At 170 °C, the density, electrical conductivity and hardness of composites are 1.904 g/cm³, 3.43 × 10³ S/m and 54 HS, respectively. Oxidation action occurring in the phenolic resin could be the main reason for the large decrease of hardness as temperature increases up to 200 °C.

Abstract: SnO₂ and Cu-SnO₂ thin films were fabricated by the sol-gel method. The influence of annealing temperature and copper addition on the morphology and microstructure of the films was studied using X-ray diffraction (XRD) and UV-Visible, respectively. The results show that the tetragonal rutile phase is evidenced by XRD with no other phases observed. The crystallinity of SnO₂ and Cu-SnO₂ thin films had been improved with the increasing annealing temperature. The grain size decreased after Cu doping. On theoretical, Pure and Cu-SnO₂ were calculated by first-principles full potential linearized augmented plane wave ultra-soft pseudo-potential method to investigate band structure.