Nd:Glass-Raman laser for water vapor dial

A tunable solid-state Raman shifted laser which was used in a water vapor Differential Absorption Lidar (DIAL) system at 9400 A is described. The DIAL transmitter is based on a tunable glass laser operating at 1.06 microns, a hydrogen Raman cell to shift the radiation to 1.88 microns, and a frequency doubling crystal. The results of measurements which characterize the output of the laser with respect to optimization of optical configuration and of Raman parameters were reported. The DIAL system was also described and preliminary atmospheric returns shown

Seasonal Ammonia Emissions from a Free-Stall Dairy in Central Texas

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FTS BAND INTENSITY MEASUREMENTS ON OCS AND N2ON_{2}O

The infrared intensities of nine absorption bands of OCS and thirteen absorption bands of $N_{2}O$ have been measured with a Fourier transform spectrometer at $0.06 cm^{-1}$ resolution. The measured bands lie between $500 cm^{-1}$ and $4600 cm^{-1}$, and include all fundamentals of each molecule and also overtone and combination bands. All measurements were made at room temperature. The partial pressure of the absorbing species ranged from 0.76 torr to 38 torr and the absorption pathlengths ranged from 1 to 15 cm resulting in pressure-pathlength products of 0.78 torr cm to 567 torr cm. The stronger bands were measured at the lower pressure-pathlengths and the weaker bands at the higher pressure-pathlengths. In all runs the absorption call was pressurized to 1 atm. with nitrogen to ensure minimal instrumental distortion of the spactral features. Care was also taken to observe any saturation of the absorption bands (which generally occur at peak absorptions greater than 40%) and omit any saturation distorted data. The band strengths were obtained directly from the slopes of Bear's law plots-integrated absorbance versus pressure-pathlength product $(\int-\ln (I/I_{0}) d\nu va P.L)$

FTS BAND INTENSITY MEASUREMENTS IN NITROUS ACID

$^{1}$ P. G. Ashmore and B. J. Tyler, J. Chem. Soc. 1017 (1961), I. R. Beattie and S. W. Bell, J. Chem. Soc. 1686 (1957), and L. Harris and K. L. Churney, J. Chem. Phys. 47, 1703 (1967).Author Institution:The infrared absorption intensities of the four in-plane fundamental bands of trans-nitrous acid (HONO) and two in-plane fundamental bands of cis-nitrous acid have been measured in the gas phase using a Fourier transform spectrometer with $0.06 cm^{-1}$ resolution. In the gas phase, nitrous acid exists in an equilibrium mixture. At room temperature $(296^{\circ})$the following equilibria must be considered: $NO+NO_{2}+H_{2}O\Leftrightarrow 2HONO, K=1.36{atm}^{-1} \\ NO+NO_{2}\Leftrightarrow N_{2}O_{3}, K=0.585 {atm}^{-1} \\ 2NO_{2}\Leftrightarrow N_{2}O_{4}, K=8.20 {atm}^{-1}$ We have used equilibrium constants from the $literature^{1}$ to determine the partial pressure of HONO over a range of conditions. In our measurements, the nitrous acid pressure was typically one torr, and the total pressure of the equilibrium mixture was typically 60 torr. The 20 cm absorption cell was pressurized to one atmosphere with dry nitrogen to minimize instrument distortion of the band shapes. Interferences in the HONO bands caused by overlapping absorptions of the other components of the mixture were digitally subtracted from the absorbance spectrum. The intensities of the $\nu_{1}$ and $\nu_{2}$ bands of $N_{2}O_{3}$ were also measured