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

DIODE LASER INTENSITY AND LINE WINTH MEASURENENTS IN THE ν1\nu_{1} AND ADJACENT ABSORPTION BANDS OF N2ON_{2}O

Author Institution:The intensities of individual rotation-vibration absorption lines of nitrous oxide $(N_{2}O)$ have been measured in the region $1210 cm^{-1}$ to $1320 cm^{-1}$ with a diode laser spectrometer. These include lines in the P and R branches of the fundamental $(10^{\circ}0-00^{\circ}0)$ band of both isotopic species $^{14}N_{2} ^{16}O$ and $^{14}N_{2} ^{18}O$, lines in the hot bands $(11^{le}0-01^{le}0)$ and $(11^{1f}0-01^{1f}0)$ of $^{14}N_{2} ^{16}O$, and several lines of the R branch of the $(02^{\circ}0-00^{\circ}0)$ overtone band of $^{14}N_{2} ^{16}O$. These measurements were made at pressures 0.5 torr to 12 torr, resulting in line widths which were typically $3\times 10^{-3}$ $cm^{-1}$. The spectra were recorded in digitized form and least-squares fit to a Voigt line profile. The individual line intensity measurements were then combined in a least-squares fit to obtain an integrated band intensity which will also be presented along with our estimate of the uncertainties The self-broadening of most of these lines has been measured. Measurements will be made of pressure broadening by $N_{2}$

MICROWAVE Q BRANCHES OF THE DISTORTION MOMENT SPECTRUM OF 16OPF3^{16}OPF_{3}

$^{1}$ I. Ozier, R. M. Lees, and M.C.L. Gerry, Can. J. Phys. 54, 1094 (1976). $^{2}$ J. G. Smith, Mol. Phys. 32, 621 (1976).Author Institution: Department of Physics, The University of British Columbia; Department of Chemistry, The University of British ColumbiaOver 140 very weak pure rotational distortion moment microwave transitions have been measured for the symmetric top phosphoryl fluoride, $OPF_{3}$ This is the first such spectrum observed in a molecule containing entirely heavy atoms. The observed transitions arose from a small component of the dipole moment induced perpendicular to the symmetry axis by centrifugal distortion, and had the selection rules $\Delta J = 0, \Delta K = \pm 3$. Values of K for the transitions were $K = \pm 6 \rightarrow \pm 9, \pm 7 \rightarrow 10, \pm 8 \rightarrow \pm 11, \pm 9 \rightarrow \pm 12, \pm 11 \rightarrow \pm 14$, and $\pm 12 \rightarrow \pm 15$, with values of J ranging from 40 to 80. The Lines were observed between 9 and 18 GHz using our sensitive Stark modulated $spectrometer,^{1}$ and had typical full widths at half maximum of $\sim$1 MHz. The spectrum has yielded on analysis values for $(A_{o} -B_{o})$, two quartic centrifugal distortion constants ($D_{K}$ and $D_{JK}$) and three sextic distortion constants, ($H_{K}, H_{KJ}$, and $H_{JK}$). The value of $(A_{o} - B_{o})$ has been combined with the literature $value^{2}$ for $B_{0}$ to give an improved molecular structure

Measurement of Chemical Vapors Emitted from Industrial Sources in an Urban Environment Using Open-path FTIR

A RAM2000 Open-Path (OP) FTIR analyzer was set up to measure ambient air continuously, with 1-min avg, over a 1-mo period at the interface between an industrial area and a residential area (Forest Park) in northwest Portland. There have been numerous complaints from the citizens who live in the Forest Park area about odors and chemicals coming from the industrial area. Twelve chemicals were detected and measured: ammonia, methanol, acetone, propylene glycol methyl ether acetate, n-butyl acetate, isobutanol, 1,1,1,2-tetrafluoroethane, chlorodifluoromethane, tetrachloroethlyene, isopropyl alcohol, 2-butanol, and chloroform. The spectral data was analyzed for 18 other chemicals that are of concern and have appeared in canister samples: benzene, toluene, three isomers of xylene, naphthalene, phenol, CCl 4, dichloromethane, formaldehyde, acetaldehyde, acrolein, styrene, hydrogen cyanide, 1,3-butadiene, 1,2-dibromoethane, 1,2-dichloroethane, and 1,1-dichloroethane. The OP-FTIR technology would be a very valuable tool for monitoring the progress of the Integrated Urban Strategy in reducing the concentrations of the urban hazardous air pollutants. OP-FTIR measurements can produce very large amounts of information on the chemical environment. This is an abstract of a paper presented at the AWMA 97th Annual Conference and Exhibition (Indianapolis, IN 6/22-25/2004)