ABSTRACT This research uses Taguchi Method, combined with Computer Aided Design and Manufacturing, processing the work piece into the saddle type. Next, diverse sampling methods are applied to measure the profile of surface with Coordinate Measuring Machine, with an aim to analyzing the main factors that influence cutting and seeking the last conditions for cutting out the curved surface; in addition, I will probe into the contribution rate of each factor which influences the precision during the process of measurement. The following results of this research are expected to be offered to the circles of vocational education as a basis of processing and measuring instruction. In this way, it will not take too much time to try and error and therefore, the practice course can be more efficient. 1. With reference to the documents that are focused on the factors affecting the cutting, this thesis, by means of Taguchi Method, shows that during the process of cutting saddle-type curved surface, the rotating speed of the axle is the most influential, whose contribution rate is 59.38%. 2. Since most documents are on circles, balls or cone objects, this thesis will aim at the measurement of saddle-type curved surface, with an intention to further the measuring technique. 3. It is found that as to the saddle-type curved surface, random sampling can get the profile of surface with minimal errors, and has no such trouble as using HSS or LHS, which can reduce time and cost. 4. In the experiment of Taguchi Method, according to analysis of variance, the influence of the sampling area is the greatest while the choice of sampling method only contributes to 3.46%.

CPU heat sinks with high efficiency of heat transfer are greatly demanded for a personal computer with high-speed computational ability. In recent years, the manufacturing technology of CPU heat sinks has got much attention and becomes indispensable for developing the high-performance CPUs.In this study, some different design criteria for the flow guide and die are proposed during an extrusion process with complex cross-sectional shapes, such as CPU heat sinks. The plastic flow pattern of the billet inside the die cavity is analyzed by using a commercial finite element package ¡§DEFORM 3D¡¨.The extrusion load, the stress and strain distribution of die, and the curvature of the product are investigated. Taguchi method is used to find the optimum extrusion condition of the die parameters. In addition, the experiments of extrusion using Al 6061 were carried out. The plastic flow pattern of the billet within the die and the dead metal zones were observed. The experimental data were compared with the analytical values to verify the validity of the proposed analytical models.

ABSTRACT In this study, two chemical mechanical polishing (CMP) wastewaters were treated by crossflow electro-microfiltration. Also studied are the effects of operation parameters on their treatment efficiencies. In the semiconductor industry, presently, CMP has become the key technique to provide global planarization on interlevel dielectrics (ILD) and metal layers of wafers. In general, the post-CMP cleaning process will produce a great quantity of CMP wastewater. Normally, CMP wastewater consists of abrasives of high concentration and stability, chemicals (e.g., oxidant and surfactant), and a tremendous mass of de-ionized water. Because of the negatively charged suspended solids in CMP wastewater, crossflow electro-microfiltration was used to treat this type of wastewater. By applying an electric field to the system, the negatively charged suspended solids were expelled from the membrane surface moving toward the anode. Not only reducing the cake formation on the membrane, enhancement of the filtration rate and permeate flux have also been found when an external electric field is applied to the filtration system. In this investigation, CMP wastewaters obtained from wafer fabs A and B were first characterized by various standard methods. In CMP wastewater A, the suspended solids were found to have a high negative zeta potential, about ¡V78 mV. Its electrical conductivity was determined to be 127.2 £gS/cm. Before testing, each CMP wastewater was pre-filtered using a filter paper of 1.2 £gm in pore size. An experimental design based on the Taguchi method was employed. The L9 orthogonal arrays were utilized to investigate the effects of four experimental factors ( i.e., electric field strength, crossflow velocity, transmembrane pressure, and membrane pore size) on the filtration rate and permeate quality in the crossflow electro-microfiltration system. When the electric field strength applied was lower than the critical electric field strength, increases of the electric field strength, transmembrane pressure, and membrane pore size were found to be beneficial to the filtration rate. The experimental results were further subjected to the analysis of variance and regular analysis. For both CMP wastewaters A and B, the electric field strength and membrane pore size were determined to be very significant parameters. In this filtration system, the optimal treatment efficiency could be achieved by using a higher electric field strength, lower crossflow velocity, higher transmembrane pressure, and larger membrane pore size. The quality of permeate thus obtained was even better than the tap water quality standards. Therefore, the permeate might be worth recycling for various purposes.

ABSTRACT In this study, two chemical mechanical polishing (CMP) wastewaters were treated by crossflow electro-microfiltration. Also studied are the effects of operation parameters on their treatment efficiencies. In the semiconductor industry, presently, CMP has become the key technique to provide global planarization on interlevel dielectrics (ILD) and metal layers of wafers. In general, the post-CMP cleaning process will produce a great quantity of CMP wastewater. Normally, CMP wastewater consists of abrasives of high concentration and stability, chemicals (e.g., oxidant and surfactant), and a tremendous mass of de-ionized water. Because of the negatively charged suspended solids in CMP wastewater, crossflow electro-microfiltration was used to treat this type of wastewater. By applying an electric field to the system, the negatively charged suspended solids were expelled from the membrane surface moving toward the anode. Not only reducing the cake formation on the membrane, enhancement of the filtration rate and permeate flux have also been found when an external electric field is applied to the filtration system. In this investigation, CMP wastewaters obtained from wafer fabs A and B were first characterized by various standard methods. In CMP wastewater A, the suspended solids were found to have a high negative zeta potential, about ¡V78 mV. Its electrical conductivity was determined to be 127.2 £gS/cm. Before testing, each CMP wastewater was pre-filtered using a filter paper of 1.2 £gm in pore size. An experimental design based on the Taguchi method was employed. The L9 orthogonal arrays were utilized to investigate the effects of four experimental factors ( i.e., electric field strength, crossflow velocity, transmembrane pressure, and membrane pore size) on the filtration rate and permeate quality in the crossflow electro-microfiltration system. When the electric field strength applied was lower than the critical electric field strength, increases of the electric field strength, transmembrane pressure, and membrane pore size were found to be beneficial to the filtration rate. The experimental results were further subjected to the analysis of variance and regular analysis. For both CMP wastewaters A and B, the electric field strength and membrane pore size were determined to be very significant parameters. In this filtration system, the optimal treatment efficiency could be achieved by using a higher electric field strength, lower crossflow velocity, higher transmembrane pressure, and larger membrane pore size. The quality of permeate thus obtained was even better than the tap water quality standards. Therefore, the permeate might be worth recycling for various purposes.

The purpose of this research is to provide a systematic design of a reciprocating tubular linear generator, which is suitable for harvesting solar thermal energy and ocean wave energy. For the structure design of this generator, the stator utilizes a slotless structure, while the mover utilizes the quasi-Halbach permanent magnet array. The operational magnetic fields are first estimated by magnetic equivalent circuit analysis, and then confirmed by three-dimensional finite element analysis. Also, parameters of the machine structure are optimized by Taguchi¡¦s method. The stator windings are selected iteratively by operational specifications and constraints. Finally, assessments of the machine operational behaviors are performed to achieve a complete and systematic design.

<p>The demands the automotive gear designer has to considerduring the gear design process have changed. To design a gearthat will not fail is still a challenging task, but now lownoise is also a main objective. Both customers and legalregulations demand noise reduction of gears. Moreover, thequality of the product is more in focus than ever before. Inaddition, the gear design process itself must be inexpensiveand quick. One can say that the gear designer faces a newdesign environment. The objective of this thesis is tocontribute to the answer to some of the questions raised inthis new design environment.</p><p>In order to respond to the new design situation, the geardesigner must consider new phenomena of gears that werepreviously not a matter of concern. One such phenomenon is anew gear failure type, Tooth Interior Fatigue Fracture (TIFF).As the gear teeth are made more slender in an attempt to reducethe stiffness variation during the mesh cycle, therebypotentially reducing the noise, the risk of TIFF is increased.The phenomenon of TIFF is explored in detail (paper III-VI)through fractographic analysis, numerical crack initiationanalysis using FEM, determination of residual stress by meansof neutron diffraction measurements, testing for determiningmaterial fatigue properties, fracture mechanical FE-analysis,sensitivity analysis and the development of an engineeringdesign method. The main findings of the analysis of TIFF arethat TIFF cracks initiate in the tooth interior, TIFF occursmainly in case hardened idlers, the fracture surface has acharacteristic plateau at approximately the mid-height of thetooth and the risk of TIFF is more pronounced in slender gearteeth.</p><p>Along with the more optimised gear design, there is atendency for the gear to be less robust. Low robustness, i.e.,great variation in performance of the product, implies a highincidence of rejects, malfunction and/or bad-will, all of whichmay have a negative effect on company earnings. As the use ofoptimisation decreases the safety margins, greater attentionhas to be paid to guaranteeing the products' robustness.Moreover, in order to be cost-effective, the qualities of thegear must be verified early in the design process, implying anextended use of simulations. In this thesis, two robustnessanalyses are presented in which the analysing tool issimulation. The first one considers robust tooth root bendingfatigue strength as the gear is exposed to mounting errors, thesecond one considers robust noise characteristics of a gearexposed to manufacturing errors, varying torque and wear. Bothof these case studies address the problem of robustness ofgears and demonstrate how it can be estimated by use ofsimulations. The main result from the former robustnessanalysis is that wide gears are more sensitive to mountingerrors, while the latter analysis showed that to achieve robustnoise characteristics of a gear it should have large helixangles, and some profile- and lead crowning should beintroduced. The transverse contact ratio is a trade-off factorin the sense that both low average noise levels and low scatterin noise due to perturbations cannot be achieved.</p><p><b>Keywords</b>: robust design, Taguchi method, gear, idler,simulations, Finite Element Method, Tooth Interior FatigueFracture, TIFF</p>

Thesis (Ph. D.)--School of Industrial and Systems Engineering, Georgia Institute of Technology, 2004. Directed by Paul H. Kvam. / Vita. Includes bibliographical references (leaves 108-113).

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Thesis (M.S.)--Ohio University, June, 1995. / Title from PDF t.p.