Carbon monoxide in the solar atmosphere I. Numerical method and two-dimensional models

The radiation hydrodynamic code CO5BOLD has been supplemented with the time-dependent treatment of chemical reaction networks. Advection of particle densities due to the hydrodynamic flow field is also included. The radiative transfer is treated frequency-independently, i.e. grey, so far. The upgraded code has been applied to two-dimensional simulations of carbon monoxide (CO) in the non-magnetic solar photosphere and low chromosphere. For this purpose a reaction network has been constructed, taking into account the reactions which are most important for the formation and dissociation of CO under the physical conditions of the solar atmosphere. The network has been strongly reduced to 27 reactions, involving the chemical species H, H2, C, O, CO, CH, OH, and a representative metal. The resulting CO number density is highest in the cool regions of the reversed granulation pattern at mid-photospheric heights and decreases strongly above. There, the CO abundance stays close to a value of 8.3 on the usual logarithmic abundance scale with [H]=12 but is reduced in hot shock waves which are a ubiquitous phenomenon of the model atmosphere. For comparison, the corresponding equilibrium densities have been calculated, based on the reaction network but also under assumption of instantaneous chemical equilibrium by applying the Rybicki & Hummer (RH) code by Uitenbroek (2001). Owing to the short chemical timescales, the assumption holds for a large fraction of the atmosphere, in particular the photosphere. In contrast, the CO number density deviates strongly from the corresponding equilibrium value in the vicinity of chromospheric shock waves. Simulations with altered reaction network clearly show that the formation channel via hydroxide (OH) is the most important one under the conditions of the solar atmosphere.Comment: 15 pages, 6 figures, final version will contain online materia

Deaths certified as asthma and use of medical services: A national case-control study

This is an open access publication. The official published version can be accessed from the link below.Background: Studies have linked asthma death to either increased or decreased use of medical services. Methods: A population based case-control study of asthma deaths in 1994–8 was performed in 22 English, six Scottish, and five Welsh health authorities/boards. All 681 subjects who died were under the age of 65 years with asthma in Part I on the death certificates. After exclusions, 532 hospital controls were matched to 532 cases for age, district, and date of asthma admission/death. Data were extracted blind from primary care records. Results: The median age of the subjects who died was 53 years; 60% of cases and 64% of controls were female. There was little difference in outpatient attendance (55% and 55%), hospital admission for asthma (51% and 54%), and median inpatient days (20 days and 15 days) in the previous 5 years. After mutual adjustment and adjustment for sex, using conditional logistic regression, three variables were independently associated with asthma death: fewer general practice contacts (odds ratio 0.82 (95% confidence interval (CI) 0.74 to 0.91) per 5 contacts) in the previous year, more home visits (1.14 (95% CI 1.08 to 1.21) per visit) in the previous year, and fewer peak expiratory flow recordings (0.83 (95% CI 0.74 to 0.92) per occasion) in the previous 3 months. These associations were similar after adjustment for markers of severity, psychosocial factors, systemic steroids, short acting bronchodilators and antibiotics, although the association with peak flow was weakened and just lost significance. Conclusion: Asthma death is associated with less use of primary care services. Both practice and patient factors may be involved and a better understanding of these may offer possibilities for reducing asthma death.This study was funded jointly between the National Research and Development Asthma Management Programme (contract number AM1/ 05/002) and the National Asthma Campaign through a grant from Glaxo Wellcome (now GlaxoSmithKline)

Commitment Bonds

This Article introduces compensating commitment bonds, which make it more affordable for a government, entity, or individual to commit to some course of action. These bonds, like traditional government or corporate bonds, can generate revenue for committing parties. A bond seller makes a commitment and promises to pay a forfeit if the seller fails to meet the bond conditions. The bond buyer pays the seller to be contractually designated as the recipient of any amounts the bond seller forfeits. This approach has potential application in a range of legal situations. Governments and other parties may use such bonds to facilitate commitments to principles from which they later may face temptation to deviate. Such bonds also can facilitate legislative compromise or the settlement of private legal disputes. The Article identifies a variety of incentive- equivalent commitment bond structures as well as the circumstances under which a particular implementation is likely to be most effective. It also explores hurdles to the use of such bonds, including concerns that the courts might find a legislature’s use of such bonds to entrench its preferences unconstitutional and that a legislature might issue such bonds but cancel them after failing to maintain a commitment

Commitment Bonds

This Article introduces compensating commitment bonds, which make it more affordable for a government, entity, or individual to commit to some course of action. These bonds, like traditional government or corporate bonds, can generate revenue for committing parties. A bond seller makes a commitment and promises to pay a forfeit if the seller fails to meet the bond conditions. The bond buyer pays the seller to be contractually designated as the recipient of any amounts the bond seller forfeits. This approach has potential application in a range of legal situations. Governments and other parties may use such bonds to facilitate commitments to principles from which they later may face temptation to deviate. Such bonds also can facilitate legislative compromise or the settlement of private legal disputes. The Article identifies a variety of incentive- equivalent commitment bond structures as well as the circumstances under which a particular implementation is likely to be most effective. It also explores hurdles to the use of such bonds, including concerns that the courts might find a legislature’s use of such bonds to entrench its preferences unconstitutional and that a legislature might issue such bonds but cancel them after failing to maintain a commitment

Structure of the outer layers of cool standard stars

Context: Among late-type red giants, an interesting change occurs in the structure of the outer atmospheric layers as one moves to later spectral types in the Hertzsprung-Russell diagram: a chromosphere is always present, but the coronal emission diminishes and a cool massive wind steps in. Aims: Where most studies have focussed on short-wavelength observations, this article explores the influence of the chromosphere and the wind on long-wavelength photometric measurements. Methods: The observational spectral energy distributions are compared with the theoretical predictions of the MARCS atmosphere models for a sample of 9 K- and M-giants. The discrepancies found are explained using basic models for flux emission originating from a chromosphere or an ionized wind. Results: For 7 out of 9 sample stars, a clear flux excess is detected at (sub)millimeter and/or centimeter wavelengths. The precise start of the excess depends upon the star under consideration. The flux at wavelengths shorter than about 1 mm is most likely dominated by an optically thick chromosphere, where an optically thick ionized wind is the main flux contributor at longer wavelengths. Conclusions: Although the optical to mid-infrared spectrum of the studied K- and M-giants is well represented by a radiative equilibrium atmospheric model, the presence of a chromosphere and/or ionized stellar wind at higher altitudes dominates the spectrum in the (sub)millimeter and centimeter wavelength ranges. The presence of a flux excess also has implications on the role of these stars as fiducial spectrophotometric calibrators in the (sub)millimeter and centimeter wavelength range.Comment: 13 pages, 6 figures, 7 pages of online material, submitted to A&

Big Data for a Deep Problem: Exploring Natural Deep Eutectic Solvent (NADES) Properties through RDKIT and Data Analytics

https://tigerprints.clemson.edu/csrp/1014/thumbnail.jp

Cone in Cone Concretions of the Stanley Group in southeastern Oklahoma

Cone in cone concretions found in the Stanley Group of Southeastern Oklahoma have a variety of external and internal attributes which allow diagenetic and theoretical models of formation to be hypothesized. Stanley Group carbonate cone in cone concretions are initially formed in sulfur reducing horizons at shallow burial depths in a poorly circulated possibly deep trough containing siliceous sediments and organic matter. Collected concretions near the town of Smithville, Oklahoma displayed four different external morphologies and four variations of mineral constituents. All concretions contained microscopic cones which initiated diffusion and/or fluid patterns and is an early cementation process that directly altered the sediment compared to the surrounding deposits. The patterns initiated ultimately controlled and recorded diagenic alterations to mineral content and structure of the concretions. Concretion mineralogy consisted of microgranular calcite, twinned lamellae calcite and siliceous precipitates which dissolved carbonates from the inside out