Improved Co I Log(gf) Values and Abundance Determinations in the Photospheres of the Sun and Metal-Poor Star HD 84937

New emission branching fraction measurements for 898 lines of the first spectrum of cobalt (Co I) are determined from hollow cathode lamp spectra recorded with the National Solar Observatory 1 m Fourier transform spectrometer on Kitt Peak, AZ and a high-resolution echelle spectrometer. Published radiative lifetimes from laser induced fluorescence measurements are combined with the branching fractions to determine accurate absolute atomic transition probabilities for the 898 lines. Hyperfine structure (hfs) constants for levels of neutral Co in the literature are surveyed and selected values are used to generate complete hfs component patterns for 195 transitions of Co I. These new laboratory data are applied to determine the Co abundance in the Sun and metal-poor star HD 84937, yielding log epsilon(Co) = 4.955 +/- 0.007 (sigma = 0.059) based on 82 Co I lines and log epsilon(Co) = 2.785 +/- 0.008 (sigma = 0.065) based on 66 Co I lines, respectively. A Saha or ionization balance test on the photosphere of HD 84937 is performed using 16 UV lines of Co II, and good agreement is found with the Co I result in this metal-poor ([Fe I/H] = -2.32, [Fe II/H] = -2.32) dwarf star. The resulting value of [Co/Fe]= +0.14 supports a rise of Co/Fe at low metallicity that has been suggested in other studies.NASA NNX10AN93GNSF AST-1211055, AST-1211585McDonald Observator

Monopoly Price Discrimination and Demand Curvature

Published as an article in: American Economic Review, 2010, vol. 100, issue 4, pages 1601-15.third-degree price discrimiation, output, monopoly, welfare

Structural studies of novel hydrogen bonds by x-ray and neutron diffraction.

The first set of measurements in this thesis discusses the hydrogen-bonding behaviour of1,3-dimesitylimidazol-2-ylidene when co-crystallised with organic acids. 1,3-dimesityiimidazol-2-ylidene is an unusual molecule in which it is possible to have a carbon with a valence of two. In the co-crystals of 1,3-dimesitylimidazol-2-ylidene with pentafluorophenol, pentachlorophenol, 2(2-hydroxidophenyl)benzoxazole or 2,6-di-tert-butyl-4-methylpyridine the 1,3-dimesitylimidazol-2-ylidene becomes protonated and uncommonly short C-H - O hydrogen bonds are formed, the shortest has a C-0 separation of 2.800(3)Å. In the 1:1 co-crystal of 1,3-dimesitylimidazol-2-ylidene and diphenylamine the first example of an N-H-C hydrogen bond is observed, with an N-C distance of 3.196(2)Å. The 1:1, 1:2 and 2:1 co-crystals of 4,4'-bipyridine and benzene-1,2,4,5-tetracarboxylic acid(pyromellitic acid) have been studied by X-ray and neutron diffraction and the 1:1 and 1:2 co-crystals of 4,4'-bipyridine and benzene-1,2-dicarboxylic acid (phthalic acid) and the 1:2 co-crystal of bis-1,2-(2-pyridinium)ethane and benzene-1,2-dicarboxylic acid have been studied by X-ray diffraction. In the short N-H- -0 hydrogen bond observed in the 2:1 co-crystal of 4,4'-bipyridine and benzene-1,2,4,5-tetracarboxylic acid (N-0 2.5220(17)Å at 20K) the hydrogen atom was observed to change position with temperature; at 20K the hydrogen lies1.207(3)Å from the nitrogen and 1.325(3)Å from the oxygen and at 296K it has moved across the hydrogen bond to lie 1.240(4)Å from the oxygen atom and 1.302(4)Å from the nitrogen atom. The same phenomenon of temperature dependent proton migration has been observed by neutron diffraction in crystals of pyridine-3,5-dicarboxylic acid and upon deuteration of the hydrogen bonds the magnitude of the effect becomes greater. Solid-state density functional theory calculations have been used to provide theoretical models for the observed behaviour and to predict the inelastic-incoherent neutron-scattering spectra for pyridine-3,5-dicarboxylicacid in different degrees of deuteration

THE ROLE OF THE WILDLIFE REFUGE IN RELIEF OF VERTEBRATE PEST DAMAGE IN AGRICULTURE

Wildlife Refuges in the upper Sacramento Valley of California carry out a very significant role in the relief of wildlife problems to agriculture. The degree and diversity of vertebrate pest control effort by these refuges vary with local conditions and with environmental and budgetary limitations. Both the California Department of Fish and Game and the U. S. Fish and Wildlife Service consider the relief of crop damage to agriculture one of their most important functions. This is demonstrated by existing programs at the Sacramento, Delevan, Colusa and Sutter National Wildlife Refuges and the California Fish and Game Gray Lodge Wildlife Area. Although the emphasis may vary on individual refuges, basically, operations are similar