Advanced Materials Research Vols. 308-310

Abstract: Aluminum composites containing 10wt. % of Al₂O₃ with 3 µm size of particles have been produced using powder metallurgy (PM) method and wear behavior of the composites were tested under dry condition. A comparison is also made with SiCp reinforced Al composite produced at the same conditions. The wear rate of both types’ composites increased with all applied loads, but wear rate of the composites was a strong function of normal load rather than that of type of particles used for the manufacturing MMCs. Furthermore, the wear rate of Al-Al₂O₃ composite was smaller than that of Al-SiCp reinforced composite, but not indicating significant differences on it. Moreover, SEM examination showed that plastic deformation was the dominant type of wear for the Al₂O₃ particle reinforced MMCs, but the fragmented-deformed layer of particles was more effective for the SiCp reinforced MMCs due to more fracturing of particles.

Abstract: Statechart has been utilized as a visual formalism for the modeling of complex systems. It illuminates the features on describing properties of causality, concurrency and synchronization. The reachability structure is used to represented dynamic model by a Boolean function. In this paper, we try to describe State invariant method and equation function for hierarchical tree diagram. Finally, we used them to analyze the urban traffic control systems which are modeled by using Statecharts. Their formalism provides a concept of propositional logic for presenting control strategy.

Abstract: In this paper, the deep-bed drying rate was analyzed under different bed depths and air temperatures. It was found that the bed depth had a greater impact on the drying efficiency, and if the initial moisture content of maize and the ventilation temperature are higher, the effect would be much more notable. The results will provide a basis for optimal design of the deep-bed drying devices.

Abstract: This study established the key integration factors (KIFs) to help participants to scrutinize the key issues during incorporating sustainability issues into engineering development projects. Firstly, Sustainability disputes in one case project were reviewed to understand their evolvement and to analyze the dispute. The key factors were identified by comparing other two types of integration cases. Secondly, focused interviews were conducted with practitioners to scrutinize the eight KIFs by analysing the interviewed opinions to ensure its applicability. The study results show that the eight KIFs were consistent with the key issues in the integration practice. These factors can remind the integration team to check the data quality, choose the appropriate assessment techniques, communicate with stakeholders, invite qualified experts , and then achieve consensus in the integration process.

Abstract: For the purposes of spiral bevel gears of cycloid gear is more and more extensive, the research on the reverse are rare phenomenon, this paper puts forward a reverse method: It’s based on three coordinates measuring system for prolate epicycloids’ bevel gear teeth profile. This method according to the forming principle of the spiral bevel gear tooth profile, with the back cone expanding the measured data of a group of good quality after simple processing, according to the involutes’ parameter equation for theoretical analysis, reverse out the base circle radius and modulus, make the bevel gear tooth profiles to reverse.

Abstract: On the basis of the analysis for the reason that causes the errors of the vertex offset, the accuracy improvement method for the STL offset model which was generated by the vertex offset algorithm was proposed by using the surface subdivision algorithm based on the center of gravity on triangular facets. The offset point of the center of gravity was generated by offset the center of gravity along the normal vectors of the triangular facets on which the center of gravity is located, and the new triangular facets are formed by connecting the offset points of the center of gravity and the offset vertexes of the triangular facets so that the more accurate offset model to be built. The case study shows that the proposed algorithm has higher accuracy than the existing vertex offset algorithm.

Abstract: 18 strains of Bacillus mucilaginosus were sampled from Poyang Lake area of Jiangxi province in China . Morphology and physio-biochemical characteristics and desilication ability on bauxite were studied. The results showed that all strains are rods and produced spores from elliptical to circular， while strains of P8、P11、P15 are short rod. Gram reaction of 18 strains are negative.The strains can use nitrites and ammonium salt as nitrogen source, and survived in the nitrogen free medium. P4、P3 showed strong desilication ability, compared to blank control the content of soluble SiO2 increased to 4.57、4.13 times respectively; P2、 P7、P9 could tolerate 4% NaCl and were growing well at the temperature ranging from 25~35 °C.

Abstract: The numerical simulation of flow field of a new rectangular suction inlet installing guide plates with different rake angles was carried out by means of the K-ε turbulence model based on the Fluent hydromechanics calculation software. And that the influences of different rake angles of the internal guide plates on the flow field were analyzed. Consequently, the optimal rake angle of 45° was defined at last. Finally, the practical rectangle suction inlet, according to the numerical simulation results, was developed by installing internal guide plates with the optimal rake angle, which optimizes the distribution of internal and external flow field and improves the average side velocities of flow. Practical test results indicate that the new rectangular suction inlet could realize the uniform thickness collection to achieve the smooth work surface when collecting the bulk materials.

Abstract: Based on the theory of structure impact dynamic and numerical optimization, application of SQP algorithm in nonlinear parameter inversion is demonstrated in this paper by combining the optimization software and finite element software. Parameter inversion of thin-walled cylinder subjected to axial impact load is studied. The material parameters of thin-walled cylinder are obtained from inversion; besides, the whole process of numerical optimization parameter inversed method is demonstrated.

Abstract: When the cylindrical laser shines on the target object, a spot can be obtained, which the edge is a closed curve, marked as C₁. The imaging of the curve C₁ on the image surface of CCD is a closed curve C₂ too. Coordinate system is established to describe the position relationship among camera, image and light source, and to analyze the principle for monocular vision and laser ring to get the information about the object depth. In order to solve the problem and make the above principle clear, the key is to work out the expression for the curve C₂ on the image surface of CCD. In order to calculate the closed curve C₂ expression, the curve C₂ will firstly be divided into two parts, the upper curve and the lower one. According to least-square polynomial, discrete points on the curves of two parts are drawn out, constraints are established and the curve equations are fitted. Then, to verify practicality of this method, a virtual model scene will be created, through which relevant data describing edge of virtual CCD image and that of a virtual spot when the virtual light source alights on the virtual object will be obtained. At last, closed curve equation will be fitted in accordance with data describing edge of virtual image; the position of space object will be fixed by making use of light source equation and closed curve equation; and a contrast will be made between the calculated value and data of the spot edge to prove whether a method to obtain the position of space objects based on monocular vision and laser ring is feasible.