Advanced Materials Research Vols. 479-481

Abstract: Trenching PZT material in a thicker PZT pyroelectric cell to improve the temperature variation rate was proposed in this study to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it opposes rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 μm and a cutting depth of 150 μm was used to fabricate the PZT pyroelectric cell with a 200 μm thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters.

Abstract: Based on four typical mining condition, such as implementation gob-side entry retaining under sandstone roof, long length and long time gob-side entry retaining, implementation gob-side entry retaining under mudstone roof and implementation gob-side entry retaining at depth of more than 900 m, this paper analysis the roadway maintenance-control in no pillar simultaneous extraction of coal and gas engineering, research on the roadway maintenance-control technology during exploitation and before mining, further study typical convergence characteristics of gob-side entry retaining after mining, drew in application of no pillar simultaneous extraction of coal and gas in deep mine, proposed evaluation about the project current existing problems and development trends.

Abstract: Electronic ballast is the important part of high pressure sodium lamp.Start-up mode of high pressure sodium lamp is the difficulty in this areas.Start-up voltage must higher than working voltage when the lamp start-up.Power supply voltage is not high to start-up the high pressure sodium lamp.So we need voltage transformer, pulse generator, resonance circuit and so on to generate the start-up voltage. We analyse the theory of electronic ballasts of high-pressure sodium lamp and make experiments in this paper. We have developed the sample of high pressure sodium lamp based on this theory,and got the obvious effect in energy-saving.

Abstract: After millions of years of competition and the natural evolution of species, the biological nature (plant leaves) has formed a number of natural and rational structure. This form of the structure and organisms inherit environmental stress exist some connection. This paper as a study of plant leaves, using numerical simulation methods to explore the structure and mechanical properties of plant leaves the relationship between: Collection of fresh plant leaves, leaf through the AutoCAD software to obtain the coordinates of the point cloud, created in the ANSYS finite element model of a simplified blade, applied uniformly distributed wind load calculations to solve; and optimal blade vibration modal analysis program.

Abstract: According to the features and requirements of link forming, the link is designed by reverse engineering and rapid prototyping. The establishing scan model, gathering data, disposal of data, reconstructing CAD model, and rapid prototyping technology have been explained in detail, the integration of reverse engineering and rapid prototyping in link forming is achieved. The results indicated that the RE/RPM can provide convenience and quick design method for new link development.

Abstract: In order to carry out the error analyses of the aluminum alloy in reverse engineering, Mastercam was used to create three-dimensional (3D) parametric solid models and automatically generate NC program files. By using the generated NC program, a simulating is processed on a milling machine. The surface of the obtained product 1 was immediately scanned by a laser scanner. Using the obtained results from the laser scanner, the three-dimensional models were created in Geomagic Studio. Reanalysis of the three dimensional models, product 2 can be obtained. Finally, Error analysis was carried out by comparing the 3D scan data with the original design models. The current research demonstrates that error analysis by the present method is feasible. However, since aluminum was selected as the processing material, the scanned data is not satisfactory; contrast error is greater after reverse engineering.

Abstract: Solve the problem of simplifying, aligning, and restoring while rebuilding a large number of point group data. First, scanning art work by using 3DFAMILY laser scanner and obtain the 3D data of its surface, then removing the desultory points on the boundary, using curvature simplification and point position alignment to revise data. Finally, fixing the loophole and modify the convex block partially and finishing up 3D reconstruction. We transform the reconstruction result into STL format file, and build the prototype of art work in Rapid Prototyping System.

Abstract: Aiming at establishing physiological consistent point correspondence between 3D faces, this paper proposes a new hierarchical correspondence method based on thin plate spline deformation called HCTD by introducing local geometric constraints. Firstly, mark feature points in unified Frankfurt Coordinate and the sample face deform based on thin plate spline function according to strict correspondences of feature points, so the sample face approximately coincide with the template; Secondly, build voxel models respectively and select vertexes with salient feature from the template as the current under-corresponding vertex, and the candidate set of the corresponding vertex on sample face is determined by local relative position geometric constraint and Euclidean Distance constraint. Finally, the optimal corresponding vertex is selected according to the weighted distance of local geometric features. Experimental results prove that HCTD can establish point correspondence of faces with higher precision than existing methods.

Abstract: A machine vision system based on Artificial Neural Network (ANN) for inspection of IC Engine block was developed to identify the misalignment and improper diminishing of holes in the IC Engine block. The developed machine vision and ANN module is compared with the commercial MATLAB® software and found results were satisfactory. This work is broadly divided into four stages, namely Intelligent inspection module, Machine Vision module, ANN module and Expert system module. A system with a camera was used to capture the various segments of head of the IC Engine block. The captured bitmap format image of IC Engine block has to be filtered to remove the noises present while capturing and the size is also altered using SPIHT method to an acceptable size and will be given as input to ANN. Generalized ANN with Back-propagation algorithm was used to inspect the IC Engine block. ANN has to be trained to provide the inspected report.

Abstract: In this paper, a flammable gas monitoring circuit is designed based on TGS813 that is a flammable gas sensor and has the characteristic of long life-pan, low prices. The principle and structure of TGS813 are introduced as well as applied in multi-channel data acquisition circuit.