Hot-pressed BaTiO3 ceramics are prepared from commercial nano-size powder supplied by Cabot. Samples have been thoroughly analysed for the crystalline phases, microstructure, including stacking faults and dislocations, by X-ray diffractometry, scanning electron microscopy, and transmission electron microscopy. This research consists of three major endeavours: (a) the analysis of stacking faults, (b) the hexagonal

Phase-shifting projected fringe profilometry (PSPFP) is powerful for 3D profile measurements. Test and analysis for accuracy of PSPFP is presented. A novel scheme to identify the accuracy of evaluated phases is propsed as well. This test scheme can be applied to any kind of measurements which use fringe projection techniques.

The first topic of this thesis is a practical load-optimized VCO design for low-jitter 5V 500 MHz digital phase-locked loop. Besides the low jitter advantage, the design also possesses another feature, i.e., fast locked time. The second topic is the half-swing PLA circuit. An additional 1/2 VDD voltage source and buffering transmission gates are inserted between the NOR planes of PLAs to erase the racing problem and shorten the rise delay as well as the fall delay of the output response such that the speed is enhanced and the dynamic power is reduced. The third topic is a novel design of a the 1.0 GHz pipelining 8-bit CLA based on the architecture we mentioned in the second topic. The operating clock frequency is 1.0 GHz and the output of the addition of two 8-bit binary numbers is done in 2 cycles ( 2.0 ns ).

This research is based on ¡§GTAW¡¨ mode, toweld the premixedferrite, molybdenum, and carbon powders on SC45 carbon steel substrate. Learning from the previous experiments, a wear test under a high temperature of 450¢J, was employed to get the Ring-disk coefficients of sliding friction about 0.3, the depletion amounts to 0.67 mg Nm per million, that exhibited a better hardness and anti-wear property than the substrate. The welding layer¡¦s solidification structure was examined by XRD,SEM, EPMA and TEM. The experimental results revealed that in the layer welded with GTAW, primary dendritic arms are of eutectic solidification structures. In X sample, £]-Mo2C is located in the dendrite closed to the un-melted zone. We can see that £^ phase (dispersed phase) with the rod shape solidified in the dendrite. And then £b-Fe3Mo3C (continuous phase) solidified between the rod spacing. In Z sample, £b-Fe3Mo3C solidified as dendrite first, and then the £^ phase solidified between the inter-dendrite. The solidification path is ¡§£\ + L ¡÷ £\ + £^ + L ¡÷ £\ + £^ + L+ £b ¡÷ £^ + £b¡¨. £^ phase and £b-Fe3Mo3C are both FCC structures in an ordered phase, and the coherence of lattice is good, with a perfect orientation relationship.

ABSTRACT The phase transition of the antiferromagnetic-torsional XY model is studied with molecular dynamics. In the process of releasing energy, we find a minimally stable state. The minimally stable state indicates the process of disordered state to ordered state when the 2nd phase transition was derived. The temperature of phase transition for the iferromagnetic-torsional XY model is lower than that for the antiferromagnetic XY model. A increase of the coefficient J2 will delay the temperature of phase transition for the antiferromagnetic-torsional XY model .

Continuous multi-phase feeding of broiler chickens was evaluated to optimize broiler nutrition and minimize environmental impact related to excess nitrogen in poultry manure. Four experiments were conducted. Experiments 1 and 2 studied effects of continuous multi-phase feeding during a 3-week starting period using battery brooders while experiments 3 and 4 evaluated multi-phase feeding during a traditional 7-week growing period using both battery brooders and floor pens. In the first and second experiments, the nutrient content of the multi-phase diets was changed every 24 hours in comparison to single-phase feeding. Results indicated that during the starter period, continuous multi-phase feeding had no significant influence on feed consumption, daily gain, feed to gain ratio or fecal nitrogen. In the third and fourth experiments, a four phase industry type broiler feeding program was compared to intensive multi-phase feeding programs created by linearly blending three different diets based on typical industry nutrient values and a commercial nutrient modeling computer program (EFG Natal®). In both intensive multi-phase feeding programs, the diets were changed every three days over a 7-week growth period. Broilers in experiment 3 were raised in Petersime battery brooders to primarily access nitrogen balance while birds in experiment 4 were raised in a floor pen on pine shaving litter to resemble commercial broiler production. The results indicated that intensive multi-phase feeding improved body weight gain and feed to gain ratio only in weeks 5 and 6 but not during the overall 7-week period. Nitrogen excretion and nitrogen retention were unaffected by the intensive multi-phase feeding systems. Economic analysis indicated that intensive multi-phase feeding programs could potentially lower feed costs per kilogram of gain. However, the high cost of implementing a continuous multi-phase feeding system may not justify the relatively small gain in lower feed cost per kilogram of gain. In conclusion, continuous multi-phase feeding of broiler chickens using corn-soy diets does not appear to be justified by either increased performance or reduced nitrogen excretion.

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In the imaging system, a blurred defocus image is a common problem. This is because different objects in the scene need different focus for imaging clearly. However, we can only have one focus distance in one picture. Therefore, the images of the other objects in different focus distance would be blurred by the faulty focuses. We apply wave front coding to solve the above defocus problem. Wave front coding is a technique that adds a phase mask in front of the lens, changing the image performance, and solving the problem of defocus. In this thesis, we used a new phase screen, computed accordingly its optical transfer function and then simulated the resulting images. We compared with other phase screens provided by other researchers for different defocus situations. From our results, our pupil and optical transfer function are slightly superior.

Reproduction de : Thèse de doctorat : Génie des procédés : Toulouse, INPT : 2004. / Titre provenant de l'écran-titre. Bibliogr. 171 réf.

Thèse doctorat : Chimie et Physico-Chimie Moléculaires : Nancy 1 : 2006. / Titre provenant de l'écran-titre.