Quenching of Carbon Monoxide and Methane in the Atmospheres of Cool Brown Dwarfs and Hot Jupiters

We explore CO-CH4 quench kinetics in the atmospheres of substellar objects using updated time-scale arguments, as suggested by a thermochemical kinetics and diffusion model that transitions from the thermochemical-equilibrium regime in the deep atmosphere to a quench-chemical regime at higher altitudes. More specifically, we examine CO quench chemistry on the T dwarf Gliese 229B and CH4 quench chemistry on the hot-Jupiter HD 189733b. We describe a method for correctly calculating reverse rate coefficients for chemical reactions, discuss the predominant pathways for CO-CH4 interconversion as indicated by the model, and demonstrate that a simple time-scale approach can be used to accurately describe the behavior of quenched species when updated reaction kinetics and mixing-length-scale assumptions are used. Proper treatment of quench kinetics has important implications for estimates of molecular abundances and/or vertical mixing rates in the atmospheres of substellar objects. Our model results indicate significantly higher Kzz values than previously estimated near the CO quench level on Gliese 229B, whereas current model-data comparisons using CH4 permit a wide range of Kzz values on HD 189733b. We also use updated reaction kinetics to revise previous estimates of the Jovian water abundance, based upon the observed abundance and chemical behavior of carbon monoxide. The CO chemical/observational constraint, along with Galileo entry probe data, suggests a water abundance of approximately 0.51-2.6x solar (for a solar value of H2O/H2=9.61E-04) in Jupiter's troposphere, assuming vertical mixing from the deep atmosphere is the only source of tropospheric CO.Comment: 30 pages, 3 figures, accepted for publication in the Astrophysical Journa

The role of conversation in health care interventions: enabling sensemaking and learning

<p>Abstract</p> <p>Background</p> <p>Those attempting to implement changes in health care settings often find that intervention efforts do not progress as expected. Unexpected outcomes are often attributed to variation and/or error in implementation processes. We argue that some unanticipated variation in intervention outcomes arises because unexpected conversations emerge during intervention attempts. The purpose of this paper is to discuss the role of conversation in shaping interventions and to explain why conversation is important in intervention efforts in health care organizations. We draw on literature from sociolinguistics and complex adaptive systems theory to create an interpretive framework and develop our theory. We use insights from a fourteen-year program of research, including both descriptive and intervention studies undertaken to understand and assist primary care practices in making sustainable changes. We enfold these literatures and these insights to articulate a common failure of overlooking the role of conversation in intervention success, and to develop a theoretical argument for the importance of paying attention to the role of conversation in health care interventions.</p> <p>Discussion</p> <p>Conversation between organizational members plays an important role in the success of interventions aimed at improving health care delivery. Conversation can facilitate intervention success because interventions often rely on new sensemaking and learning, and these are accomplished through conversation. Conversely, conversation can block the success of an intervention by inhibiting sensemaking and learning. Furthermore, the existing relationship contexts of an organization can influence these conversational possibilities. We argue that the likelihood of intervention success will increase if the role of conversation is considered in the intervention process.</p> <p>Summary</p> <p>The generation of productive conversation should be considered as one of the foundations of intervention efforts. We suggest that intervention facilitators consider the following actions as strategies for reducing the barriers that conversation can present and for using conversation to leverage improvement change: evaluate existing conversation and relationship systems, look for and leverage unexpected conversation, create time and space where conversation can unfold, use conversation to help people manage uncertainty, use conversation to help reorganize relationships, and build social interaction competence.</p

Relationship or revenue: potential management conflicts between customer relationship management and hotel revenue management

The concepts of customer relationship management (CRM) and revenue management (RevM) have been embraced by managers in the hospitality industry although, in practice, companies may find it difficult to accommodate both fully. This paper examines the compatibility between the two practices and discusses the possible management conflicts that occur from both account managers’ and revenue managers’ viewpoints. Findings gathered from an international hotel company reveal several causes of potential management conflicts including: management goals, management timescales, perceived business assets, performance indicators and management foci between CRM and RevM due to divergence occurring in managers’ priorities and in their approaches to achieving their individual set goals. These differences have rarely been comprehensively investigated in previous studies, yet are vital in integrating CRM and RevM practices

A Variable Mid-infrared Synchrotron Break Associated with the Compact Jet in GX 339-4.

Many X-ray binaries remain undetected in the mid-infrared, a regime where emission from their compact jets is likely to dominate. Here, we report the detection of the black hole binary GX 339-4 with the Wide-field Infrared Survey Explorer (WISE) during a very bright, hard accretion state in 2010. Combined with a rich contemporaneous multiwavelength dataset, clear spectral curvature is found in the infrared, associated with the peak flux density expected from the compact jet. An optically-thin slope of ~-0.7 and a jet radiative power of >6x10^{35} erg/s (d/8 kpc)^2 are measured. A ~24 h WISE light curve shows dramatic variations in mid-infrared spectral slope on timescales at least as short as the satellite orbital period ~95 mins. There is also significant change during one pair of observations spaced by only 11 s. These variations imply that the spectral break associated with the transition from self-absorbed to optically-thin jet synchrotron radiation must be varying across the full wavelength range of ~3-22 microns that WISE is sensitive to, and more. Based on four-band simultaneous mid-infrared detections, the break lies at ~5x10^{13} Hz in at least two epochs of observation, consistent with a magnetic field B~1.5x10^4 G assuming a single-zone synchrotron emission region. The observed variability implies that either B, or the size of the acceleration zone above the jet base, are being modulated by factors of ~10 on relatively-short timescales.Comment: ApJL vol. 740, issue 1, L1