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Controlling of the Goos-Hanchen (GH) shifts of the reflected and transmitted probe pulses through a cavity containing four-level GaAs/AlGaAs quantum dot with 15 periods of 17.5 nm GaAs wells and 25-nm Al0.3Ga0.7As barriers is investigated. Under appropriate conditions, the probe absorption can be converted to the probe gain, therefore, the controlling of negative and positive GH shift in the both reflected and transmitted probe beams can be occurred simultaneously. Our obtained results show that the group index of the probe beams could be negative or positive in both reflected and transmitted pulses. Therefore, simultaneous subluminal or superluminal light propagation in reflected and transmitted pulses can be achieved.

Development of hardware and CFD codes, especially in turbulence model and optimization of numerical codes has led to increment in usage of CFD which is capable of simulating different experimental situations take place at laboratory. Particularly in issues related to turbo machinery, two-dimensional test of blades, three-dimensional investigation of different stages and studying the effect of different parameters are very costly. By means of CFD modeling all these issues are accessible. Actual flow within the compressor is three dimensional and fully turbulent due to geometry complexity, flow velocity and viscosity. For this reason it has become more and more popular to perform 3D numerical studies. In this study three-dimensional analysis of flow in a two stage centrifugal compressor is performed. Since no experimental data is available to evaluate the results of the present numerical analysis, validation is done by using experimental data of the gas turbine set up at Sharif University of Technology Laboratory. Numerical results are used for the evaluation of the slip factor models and finally, the effects of inlet gas composition and inlet total pressure on characteristic map are investigated.

A nitridation technique is proposed for ultrathin, SiO{sub 2} oxides in deep submicron CMOS technology, which involves direct implantation of molecular nitrogen (N{sub 2}) into the silicon substrate. N{sub 2} ions were implanted into silicon at different doses and energies, through a 150 {angstrom} thick screen oxide. In this study the effect of implanted N atoms on silicon oxidation, and SiO{sub 2} oxide nitridation process have been studied. Two groups of the N{sub 2}-implanted wafers were used: wafers from one group were annealed prior to the screen oxide removal, whereas wafers of the other group did not receive this anneal. It is shown that nitridation can be achieved both ways, allowing this technique to be easily integrated into a semiconductor IC fabrication process.

Objective— Inflammatory markers are associated with vascular disease; however, variation in the acute phase response (APR) has not been evaluated. We evaluated whether the APR magnitude in men with severe carotid artery disease (CAAD) (>80% stenosis) differed from that of men without stenosis ( Methods and Results— White males with (n=43) and without (n=61) severe CAAD receiving clinical influenza vaccinations were recruited. Their baseline and 24-hour after -vaccination blood samples were assayed for C-reactive protein (CRP), IL-6, and serum amyloid-a (SAA). In vivo APR to vaccination was measurable and varied among subjects. Adjusted for age, smoking, oral hypoglycemics, aspirin, and stain use, the relative 24-hour changes in levels of ln(CRP), ln(IL-6), and ln(SAA) were higher in men with CAAD than in men without, but only the SAA response was significant ( P =0.02); the relative SAA response was 1.6 (95% confidence interval, 1.1 to 2.5) times higher in men with than without CAAD. The APR for all markers appeared to be independent of baseline levels. Conclusions— Influenza vaccination results in a mild, but measurable, APR in men with and without CAAD. SAA APR variability may be a predictor of severe vascular disease that is independent of basal SAA level.

Direct nitrogen implant into Si substrate prior to gate oxidation has been proposed to grow multiple gate oxide thicknesses on a single wafer. In this letter, we have studied the reliability of gate oxide grown on nitrogen‐implanted Si substrate. The effects of implant doses, sacrificial oxide thicknesses, and gate oxide thicknesses on gate oxide reliability have been investigated. It was found that there is a tradeoff between oxide thickness control and gate oxide reliability.

A method is proposed that allows the growth of gate oxides of different thicknesses on a single wafer. The method does not require masking the gate oxide during oxidation with its inherent risk to the oxide quality, but rather relies on the implant of nitrogen into the silicon wafer before both oxide growth and preoxidation cleans. This implant is performed at the same step as the normal threshold voltage implants, avoiding possible contamination. Using nitrogen implant doses of the order of 3/spl times/10/sup 14/-3/spl times/10/sup 15/ cm/sup -2/, it is shown that it is possible to grow oxides of 30-70 /spl Aring/, for a process with a nominal oxide thickness of 90 /spl Aring/. >