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The Measurement of Small Angles Using Optical-Reading Theodolites and American- Design Transits
Effects of Urethan on Fish Epithelial and Fibroblast Cells in Vitro
The effects of urethan on RTG-2 and FHM cells were studied in vitro, by using the mitotic index, it was determined that 0.3 percent urethan caused an increase in the rate of cell division while higher concentrations (0.6, 0.9, 1.2, and 1.5 percent) caused either a decrease in the rate or a cessation of cell division. Concentrations of urethan higher than 1.5 percent killed the cells. The mitotic index data also indicated that epithelial cells continued to divide at a higher concentration of urethan than did the fibroblast cells. The morphological effects of urethan on the two cell lines were also investigated. These effects included vacuolization of the cytoplasm, lobed and enlarged nuclei, and in some cells the cytoplasm almost completely disappeared and the nucleus developed a thick membrane oround it so that the cells resembled small lymphocytes
Adaptive optics in coherent lidar wind measurements: A feasibility study
Laser Doppler radar (lidar) is widely used for remote sensing of wind velocities. Usable wavelengths for the laser are limited by the effects of atmospheric turbulence. An adaptive optical system is proposed to compensate for turbulence effects on signal power. The feasibility of an adaptive system is considered in light of the effects of speckle from the aerosol target. It is concluded that adaptive optics is a promising technique for improving the performance of a 2 micron lidar wind measurement system. The chief technical challenges are a laser that will give the required output and pulse repetition rate, a combined Hartmann sensor and heterodyne detector, and a suitable reconstruction algorithm
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