Observation of vibrationally excited nitrogen with a simplified electron transmission apparatus

A simple electron transmission apparatus is used to observe vibrationally excited N2 in the first two vibrational levels. The method is based on the pronounced peaks appearing in the total electron scattering cross section in the range of energy 2–4 eV. Because of the wide spacing between these peaks, good energy resolution is not required and measurements can be performed without an electron monochromator

Electron transmission study of the temporary negative ion states of selected benzenoid and conjugated aromatic hydrocarbons

Electron transmission spectroscopy is utilized to determine the vertical electron affinities and to characterize the temporary anion states of a series of alternant hydrocarbons including benzene, naphthalene, anthracene, tetracene, styrene, and cis- and trans-stilbene. The vibrational structure present in the low lying resonances is interpreted in light of the charge distributions of the temporarily occupied orbitals. The energies of the anion states are compared with the predictions of PPP, PPP-CI, and HAM calculations, the pairing theorem and with the results from optical absorption measurements on the ground state anions in rigid glasses

Detection of vibrationally excited nitrogen by trapped electron and electron transmission methods

Two techniques for detection of vibrationally excited nitrogen using low-energy electron scattering are described. The first technique uses the trapped electron method to observe excitation from N2ν into the B3Пg state near threshold. From the known Franck-Condon factors, the contribution from excited vibrational levels may be unfolded. The second technique employs the electron transmission method to detect sharp structure in the total scattering cross section resulting from the formation of temporary negative ions. Because of uncertainties in the total scattering cross sections from each of the vibrational levels, the transmission method is less accurate than the trapped electron technique. As a consistency check, the vibrational temperature of N2 downstream from a microwave discharge is determined as a function of the discharge power. Within their respective error limits, the two methods are in good agreement

Low-energy electron scattering from Mg, Zn, Cd and Hg: shape resonances and electron affinities

Measurements of electron scattering at low energy from Mg, Zn, Cd and Hg have been carried out using the electron transmission method. A large shape resonance is observed for each element which we identify with the (ns2np)2P ground state of the negative ion. The electron affinities in eV are found to be Mg(–0.15), Zn(–0.49), Cd(–0,33) and Hg(–0.63) with an error of ±0.03 eV. The results are compared with the available theoretical predictions

Electron Transmission Studies of the Negative Ion States of Substituted Benzenes in the Gas Phase

Temporary negative ions of benzene, aniline, phenol, anisole, fluoro-, chloro-, and bromobenzene, formed in the gas phase by capture of electrons into the low-lying π* orbitals, are studied by means of electron transmission spectroscopy. The electron affinities are determined and their relative values are interpreted in terms of resonance and inductive effects

Systemic, renal, and colonic effects of intravenous and enteral rehydration in horses

Background: Intravenous (IV) and intragastric (IG) administration of fluid therapy are commonly used in equine practice, but there are limited data on the systemic, renal, and enteric effects. Hypothesis: IV fluid administration will increase intestinal and fecal hydration in a rate-dependent manner after hypertonic dehydration, but will be associated with significant urinary water and electrolyte loss. Equivalent volumes of IG plain water will result in comparatively greater intestinal hydration with less renal loss. Animals: Six Thoroughbred geldings. Methods: Experimental study. 6 by 6 Latin square design investigating constant rate IV administration at 50, 100, and 150 mL/kg/d over 24 hours in horses dehydrated by water deprivation. Equivalent volumes of IG plain water were administered by 4 bolus doses over 24 hours. Results: Water deprivation resulted in a significant decrease in the percentage of fecal water, and increases in serum and urine osmolality. IV fluids administered at 100 and 150 mL/kg/d restored fecal hydration, but increasing the rate from 100 to 150 mL/kg/d did not confer any additional intestinal benefit, but did result in significantly greater urine production and sodium loss. Equivalent 24-hour volumes of plain water resulted in greater intestinal water and less urine output. Conclusions and Clinical Importance: IV polyionic isotonic fluids can be used to hydrate intestinal contents in situations where enteral fluids are impractical. IV fluids administered at three times maintenance are no more efficacious and might be associated with adverse physiological findings after withdrawal. Bolus dosing of IG water can be used to restore intestinal water with minimal adverse effects