Constrained control using convex optimization

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1997.Includes bibliographical references (p. 113-121).by John Marc Shewchun.M.S

Thermal conductivity of Tl2Ba2Ca2Cu3O10 ceramics from 300 K down to 0.1 K

Thermal conductivity, [varkappa], of two ceramic samples of Tl2Ba2Ca2Cu3O10 has been measured over a temperature range from 300 K down to 0.1 K. At high temperatures, the data show features similar to the thermal conductivity of Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O ceramics in both the magnitude and the temperature dependence. Specifically, a sudden increase in the thermal conductivity is observed at the onset of a superconducting transition near 120 K culminating in a pronounced maximum of [varkappa] around 75 K and an eventual rapid decrease of the thermal conductivity at lower temperatures. From 5 K down to 0.1 K we observe the thermal conductivity to decrease with an average power law exponent between 2.4 and 2.5. Such a temperature dependence is comparable with that for sintered Bi-Sr-Ca-Cu-O samples, but differs from the quadratic variation typical for Bi-Sr-Ca-Cu-O single crystals and the T-linear asymptotic behavior characteristic of Y-Ba-Cu-O and La-Sr-Cu-O ceramics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29278/1/0000337.pd

Temperature-Induced Wavelength Shift of Electron-Beam-Pumped Lasers from CdSe, CdS, and ZnO

Experimental results on the temperature dependence of the laser frequency and threshold pump power are presented in the range from liquid helium to room temperature for electron-beam-pumped CdSe, CdS, and ZnO lasers. A linear shift of the laser frequency at high temperatures and a relatively slow linear increase of threshold with increasing temperature are found. A model is proposed that takes into account the reabsorption in the crystal below the lowest exciton energy. The results of this model are in quantitative agreement with the experimental data. The absorption coefficient at the laser frequency is determined in the three materials

Preparation and Characterization of Cu2 S and CuInS2 Films on Various Substrates for Photovoltaic Junctions

[[fileno]]2030170030059[[department]]電機工程學