3 μm laser performance of Ho:YAlO3 andNd,Ho:YAlO3

A study of the 3-μm laser transitions in Ho:YAlO₃ and Nd,Ho:YAlO₃ using both flashlamp and laser pumping is discussed. Fluorescence measurements for the Nd,Ho:YAlO₃ rod indicate that the neodymium is effective in quenching the lower holmium laser level and in sensitizing the upper level. Intracavity laser pumping of Ho:YAlO₃ produced laser lines at 2.92 and 2.85 μm and demonstrated high efficiency     

Post-subsidence deformations of loess soils

Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 4, pp. 19–21, July–August, 1990.     

High-Current Photodetectors as Efficient, Linear, and High-Power RF Output Stages

Recent progress in high-current photodiodes now makes it possible to efficiently generate over 26 dBm of RF power directly from the output of a photodiode. This paper describes two photodetector designs which demonstrate excellent large- and small-signal behavior. Maximum small-signal compression currents have increased to over 700 mA at 300 MHz. Output RF power amplifier stage efficiencies of over 45% (class AB operation) and 35% (class A) have been achieved from 0.3 to 6 GHz with RF power outputs over 26 dBm. The linearity figure of merit (LFOM) is also shown to be greater than 50, leading to the possibility of implementing very high linearity RF power amplifiers in the future.     

Closures in the moment method for modeling complex chemical reactions in turbulent flows

Closures used in the moment method for describing the macrokinetics of fast consecutive-parallel reactions in turbulent flows are analyzed. Although the calculations involving these closures sometimes lead to physically meaningless curves, the moment equations can be used to predict the final results of the process. For statistically uniform turbulent fields, the closures were modified to take into account the ratio of the reaction and micromixing rates. The conditions are derived under which the product flow would only contain the reaction products.