Chemical Equilibrium Abundances in Brown Dwarf and Extrasolar Giant Planet Atmospheres

We calculate detailed chemical abundance profiles for a variety of brown dwarf and extrasolar giant planet atmosphere models, focusing in particular on Gliese 229B, and derive the systematics of the changes in the dominant reservoirs of the major elements with altitude and temperature. We assume an Anders and Grevesse (1989) solar composition of 27 chemical elements and track 330 gas--phase species, including the monatomic forms of the elements, as well as about 120 condensates. We address the issue of the formation and composition of clouds in the cool atmospheres of substellar objects and explore the rain out and depletion of refractories. We conclude that the opacity of clouds of low--temperature ($\le$900 K), small--radius condensibles (specific chlorides and sulfides), may be responsible for the steep spectrum of Gliese 229B observed in the near infrared below 1 \mic. Furthermore, we assemble a temperature sequence of chemical transitions in substellar atmospheres that may be used to anchor and define a sequence of spectral types for substellar objects with T$_{eff}$s from $\sim$2200 K to $\sim$100 K.Comment: 57 pages total, LaTeX, 14 figures, 5 tables, also available in uuencoded, gzipped, and tarred form via anonymous ftp at www.astrophysics.arizona.edu (cd to pub/burrows/chem), submitted to Ap.

NASA Ares I Launch Vehicle Roll and Reaction Control Systems Design Status

This paper provides an update of design status following the preliminary design review of NASA s Ares I first stage roll and upper stage reaction control systems. The Ares I launch vehicle has been chosen to return humans to the moon, mars, and beyond. It consists of a first stage five segment solid rocket booster and an upper stage liquid bi-propellant J-2X engine. Similar to many launch vehicles, the Ares I has reaction control systems used to provide the vehicle with three degrees of freedom stabilization during the mission. During launch, the first stage roll control system will provide the Ares I with the ability to counteract induced roll torque. After first stage booster separation, the upper stage reaction control system will provide the upper stage element with three degrees of freedom control as needed. Trade studies and design assessments conducted on the roll and reaction control systems include: propellant selection, thruster arrangement, pressurization system configuration, and system component trades. Since successful completion of the preliminary design review, work has progressed towards the critical design review with accomplishments made in the following areas: pressurant / propellant tank, thruster assembly, and other component configurations, as well as thruster module design, and waterhammer mitigation approach. Also, results from early development testing are discussed along with plans for upcoming system testing. This paper concludes by summarizing the process of down selecting to the current baseline configuration for the Ares I roll and reaction control systems

The Effect of Bundled Payment on Emergency Department Use: Alternative Quality Contract Effects After Year One

ObjectivesThe objective was to identify the effect of the Alternative Quality Contract (AQC), a global payment system implemented by Blue Cross Blue Shield (BCBS) of Massachusetts in 2009, on emergency department (ED) presentations.MethodsBlue Cross Blue Shield of Massachusetts claims from 2006 through 2009 for 332,624 enrollees whose primary care physicians (PCPs) enrolled in the AQC, and 1,296,399 whose PCPs were not enrolled in the AQC, were evaluated. A pre–post, intervention–control, propensity‐scored difference‐in‐difference approach was used to isolate the AQC effect on ED visits. The analysis adjusted for age, sex, health status, and secular trends to compare ED use between the treatment and control groups.ResultsOverall, secular trends showed that the number of ED visits decreased slightly for both treatment and control groups. The adjusted analysis of the AQC group showed decreases from 0.131 to 0.127 visits per member/quarter, and the control group decreased from 0.157 to 0.152 visits per member/quarter. The difference‐in‐difference analysis showed the AQC had no statistically significant effect on total ED use compared to the control group.ConclusionsIn the first year of this AQC, we did not find evidence of change in aggregate ED use. Similar global budget programs may not alter ED use in the initial implementation period.ResumenEfecto del Pago Combinado en el Uso del Servicio de Urgencias: Los Efectos del Alternative Quality Contract tras un AñoObjetivosIdentificar el efecto del Alternative Quality Contract (AQC), un sistema de pago global implementado por el Blue Cross Blue Shield de Massachusetts en 2009, en las visitas a los servicios de urgencias (SU).MetodologíaSe evaluaron los 332.624 miembros cuyo médico de atención primaria (MAP) estaba incluido en el AQC y los 1.296.399 cuyo MAP no estaba incluido en el AQC del Blue Cross Blue Shield de Massachusetts de 2006 hasta 2009. Para identificar el efecto del AQC en las visitas al SU, se utilizó un diseño pre‐post, intervención‐control, con una aproximación por puntuación de propensión diferencia en diferencia. El análisis se ajustó por edad, sexo, estado de salud y tendencias seculares para comparar el uso del SU entre los grupos tratamiento y control.ResultadosDel total, las tendencias seculares mostraron que el número de visitas al SU descendió discretamente tanto para el grupo tratamiento como control. El análisis ajustado del grupo AQC mostró un descenso de 0,131 a 0,127 visitas por miembro/cuartil, y el grupo control descendió de 0,157 a 0,152 visitas por miembro/cuartil. El análisis de diferencia en diferencia mostró que el AQC no tuvo efecto estadísticamente significativo en el uso total del SU en comparación con el grupo control.ConclusionesEn su primer año, el AQC no tuvo un efecto significativo en el uso del SU. PLos programas económicos globales similares pueden no alterar la utilización del SU en el periodo inicial de implementación.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112205/1/acem12205-sup-0001-DataSupplementS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112205/2/acem12205.pd

Microstructures Manufactured in Diamond by Use of Laser Micromachining.

Different microstructures were created on the surface of a polycrystalline diamond plate (obtained by microwave plasma-enhanced chemical vapor deposition-MW PECVD process) by use of a nanosecond pulsed DPSS (diode pumped solid state) laser with a 355 nm wavelength and a galvanometer scanning system. Different average powers (5 to 11 W), scanning speeds (50 to 400 mm/s) and scan line spacings ("hatch spacing") (5 to 20 µm) were applied. The microstructures were then examined using scanning electron microscopy, confocal microscopy and Raman spectroscopy techniques. Microstructures exhibiting excellent geometry were obtained. The precise geometries of the microstructures, exhibiting good perpendicularity, deep channels and smooth surfaces show that the laser microprocessing can be applied in manufacturing diamond microfluidic devices. Raman spectra show small differences depending on the process parameters used. In some cases, the diamond band (at 1332 cm-1) after laser modification of material is only slightly wider and shifted, but with no additional peaks, indicating that the diamond is almost not changed after laser interaction. Some parameters did show that the modification of material had occurred and additional peaks in Raman spectra (typical for low-quality chemical vapor deposition CVD diamond) appeared, indicating the growing disorder of material or manufacturing of the new carbon phase

Development and Validation of the Five-Factor LAMBI Measure of God Representations

God representations are complex and there is no standard, relatively short, and easy to administer measure reflecting both anthropomorphic and abstract representations of God. We developed a new measure with five dimensions: Limitless, Authoritarian, Mystical, Benevolent, and Ineffable (the LAMBI scale). In Study 1, we used exploratory factor analysis to examine the factor structure of a preliminary list of 41 common adjectives that people might use to describe God. In Study 2, we identified the 25 best-fitting items, using confirmatory factor analysis to show that a five-factor model fit well, and began to validate the new scale using measures of religious commitment, individualistic spirituality, and Quest. In Study 3, we found the scale has good test-retest reliability. In Study 4, we examined the contribution of the LAMBI scales in predicting conservatism, values, and beliefs, above and beyond two existing measures of God representations. In Study 5, we used latent profile analysis to identify four response patterns across the five dimensions: Relational, Abstract, Unbelief, and Amorphous (no differences across the five dimensions) and show little relation between these profiles and religious group membership. We conclude that the LAMBI scale assesses important individual differences in thinking about God and can potentially be used to predict beliefs and social attitudes

Theoretical Transit Spectra for GJ 1214b and Other "Super-Earths"

We present new calculations of transit spectra of super-Earths that allow for atmospheres with arbitrary proportions of common molecular species and haze. We test this method with generic spectra, reproducing the expected systematics and absorption features, then apply it to the nearby super-Earth GJ 1214b, which has produced conflicting observational data, leaving the questions of a hydrogen-rich versus hydrogen-poor atmosphere and the water content of the atmosphere ambiguous. We present representative transit spectra for a range of classes of atmosphere models for GJ 1214b. Our analysis supports a hydrogen-rich atmosphere with a cloud or haze layer, although a hydrogen-poor model with less than 10% water is not ruled out. Several classes of models are ruled out, however, including hydrogen-rich atmospheres with no haze, hydrogen-rich atmospheres with a haze of about 0.01-micron tholin particles, and hydrogen-poor atmospheres with major sources of absorption other than water. We propose an observational test to distinguish hydrogen-rich from hydrogen-poor atmospheres. Finally, we provide a library of theoretical transit spectra for super-Earths with a broad range of parameters to facilitate future comparison with anticipated data.Comment: 33 pages, 21 figures, 3 table

Model atmospheres for massive gas giants with thick clouds: Application to the HR 8799 planets and predictions for future detections

We have generated an extensive new suite of massive giant planet atmosphere models and used it to obtain fits to photometric data for the planets HR 8799b, c, and d. We consider a wide range of cloudy and cloud-free models. The cloudy models incorporate different geometrical and optical thicknesses, modal particle sizes, and metallicities. For each planet and set of cloud parameters, we explore grids in gravity and effective temperature, with which we determine constraints on the planet's mass and age. Our new models yield statistically significant fits to the data, and conclusively confirm that the HR 8799 planets have much thicker clouds than those required to explain data for typical L and T dwarfs. Both models with 1) physically thick forsterite clouds and a 60-micron modal particle size and 2) clouds made of 1 micron-sized pure iron droplets and 1% supersaturation fit the data. Current data are insufficient to accurately constrain the microscopic cloud properties, such as composition and particle size. The range of best-estimated masses for HR 8799b, HR 8799c, and HR 8799d conservatively span 2-12 M_J, 6-13 M_J, and 3-11 M_J, respectively and imply coeval ages between ~10 and ~150 Myr, consistent with previously reported stellar age. The best-fit temperatures and gravities are slightly lower than values obtained by Currie et al. (2011) using even thicker cloud models. Finally, we use these models to predict the near-to-mid IR colors of soon-to-be imaged planets. Our models predict that planet-mass objects follow a locus in some near-to-mid IR color-magnitude diagrams that is clearly separable from the standard L/T dwarf locus for field brown dwarfs.Comment: Accepted for publication in Ap