Advanced Materials Research Vols. 156-157

Abstract: A double strand silk semi-automatic machine was designed. The numbers, length, twist, rotation direction and speed of the double strand silk it manufactured can be changed according to the engineer need. The end of strand silk it’s produced has a ring which can avoid split, which resolve the traditional silk end split problem.

Abstract: Subassembly has an important role in aircraft manufacturing. There are different shop orders at different periods, so subassembly system need to adjust production capacity through reallocation of resources. Based on graphic ant colony algorithm(GACA), an optimal resource allocation method was proposed on aircraft subassembly system. In the method, first, a Petri Net(PN) model was used to describe the logic of tasks and resources in system. Next, to support solving process of GACA, structure graph for ant routing was designed by PN model. Then according to features of aircraft subassembly, solving rules and procedures of GACA are discussed in detail, which can obtain an optimal resource allocation scheme by requirement of production capacity adjustment. In addition, an example on flaperon assembly was introduced and the result demonstrated the functionality of the method.

Abstract: Adsorption of dye from dyeing wastewater had been investigated using cross-linked chitosan beads as an adsorbent. The chitosan adsorbent was characterized by SEM, FT-IR and porosity [P]. Various parameters such as concentration of adsorbent (0.5 g/200mL to 2.5 g/200mL), pH (3-11), initial concentration of dye (50-250mg/L) and temperature (15-45 ) of adsorbate were studied. Langmuir and Freundlich isotherms were used to analyze the equilibrium data at different temperatures. Freundlich isotherm showed better correlation coefficient than the other models at all temperatures studied. The cross-linked chitosan adsorbent exhibits a high adsorption capacity to remove dye. And the adsorbent still has good adsorption capability after being reclaimed for 6 times. This study indicates that cross-linked chitosan is a promising adsorbent for removing dye from dyeing wastewater.

Abstract: A modified phenolic resin containing tertiary amine oxide was prepared via a two-step method. Epoxy phenolic resin, F-48, was reacted with dimethylamine to give the phenolic resin containing the tertiary amine group, which was then oxidized with hydrogen peroxide to obtain the target product. The tertiary amine oxide-containing resin could easily dissolve in water. However, it became water insoluble after heat treatment at a high temperature such as 160 °C. Thermal properties of the tertiary amine oxide resin were studied with DSC and TGA. A thermo-sensitive film comprising the prepared resin and an IR-dye was prepared and laser-induced thermal imaging was also conducted. This material might be used to develop new chemistry-free printing plates.

Abstract: In this article, a drawing die is researched in order to obtain the dynamic load and stress distributions and determine the potential fatigue location in it. The stress fields of the drawing die in the drawing process and their changing rules were studied through finite element method. The dynamic simulation of stress changing state has been realized, and the potential fatigue locations in the die were also determined. Based on the conclusion, the cavity die was divided into the substrate part and the wear-resistant part according to the stress distribution. Fatigue life estimations were made on the homogeneous die and the die with bi-materials. The example showed that bi-materials design can increase the service life while greatly reduces the cost of die material. The conclusions drawn conform to reality and have realistic significance.

Abstract: Waste rubber crumbs were partially oxidized and used as additives of mortars and have shown promising results in this study. SEM was used to observe the microstructure of the interfacial surfaces between cement hydration products (C-S-H) and rubber crumbs. SEM imagines showed that, in the interfacial zone, mortars with partially oxidized rubber crumbs had more uniform C-S-H distribution than that of mortars with as- received rubber crumbs. The compressive, flexural, and tensile strengths of mortars that included partially oxidized rubber crumbs also increased significantly.

Abstract: In order to reveal the physical mechanism of air hammer drilling process, using the finite element methods (FEM), a three-dimensional (3D) contact model of full-scale bit, full-scale teeth and rock is established by using free meshing method. We use a Mohr-Coulomb type material model to describe when and how rock fails, and a triangular wave to replace the stress wave. Using the finite element analysis software (ANSYS), the 3D contact analysis of the bit, teeth and rock is carried out. The results show that: aggressive tensile failure may be primarily responsible for rock breakage in air hammer drilling, while compressive failure (or shear failure) may only contribute as a minor player; the distribution of the fragmentation dents can be used to verify the rationality of tooth arrangement; the larger tooth-hole stress of the outside rows mainly responses for the bit failure, while the larger tooth stress of the inside rows contributes as a secondary factor. The results are further calibrated with a series of field applications and research results.

Abstract: This papers deals with the study of the fayalite with high content of iron in the initial layer of coal ash, using the generalized gradient approximation and Perdew-Wang91 algorithm based on the Quantum chemistry. By calculating, we found that the gap between the highest occupied molecular orbital(HOMO) energy and the lowest unoccupied molecular orbital(LUMO) energy of the Fayalite is very small, so the structure is unstable. Thus show that the water-cooling wall slagging more active due to Fe atoms,prone to transformations of physical phenomena.

Abstract: Based on the failure mode of air hammer bit, a mechanical model of the tooth on the inclined plane is established. And then a new air hammer flat bit with double declined planes and a big central plat (the outer inclined plane is 40° and the inner one is 20°) is designed. In order to reduce the design cost and cut down the design cycle, we establish a 3D contact model of 12 1/4″ full-scale flat bit, teeth and rock to choose a better end face structure from single and double declined planes, verify the rationality of bit parameters and tooth arrangement, design reasonable shrink range between tooth and tooth-Hole. This 3D FEM methodology for air hammer bit design is economical and useful, it can be used to optimize bit structure and design a new bit.

Abstract: The Ba doped tantalum oxide (Ba-Ta2O5) particles were synthesized using low temperature hydrothermal method. The phase structure of samples was characterized by X-ray diffraction (XRD). The result showed that Ba-Ta2O5 had still good crystallinity and belonged to rhombic crystal. The catalytic activity of samples was investigated with the degradation methylene blue (MB) under visible light. The degradation efficiency attained 82% when the reaction time was 12 h. The kinetics of MB degradation was respect to the first-order.