Leads integral with the internal interconnection that penetrate the molded wall of a package

Multiplicity of external ribbon leads makes possible connections to a sealed or encapsulated microassembly. The leads are integral with the internal connections on a single part that can be fabricated economically by fine-detail electroplating

Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets

We address disequilibrum abundances of some simple molecules in the atmospheres of solar composition brown dwarfs and self-luminous extrasolar giant planets using a kinetics-based 1D atmospheric chemistry model. Our approach is to use the full kinetics model to survey the parameter space with effective temperatures between 500 K and 1100 K. In all of these worlds equilibrium chemistry favors CH4 over CO in the parts of the atmosphere that can be seen from Earth, but in most disequilibrium favors CO. The small surface gravity of a planet strongly discriminates against CH4 when compared to an otherwise comparable brown dwarf. If vertical mixing is like Jupiter's, the transition from methane to CO occurs at 500 K in a planet. Sluggish vertical mixing can raise this to 600 K; but clouds or more vigorous vertical mixing could lower this to 400 K. The comparable thresholds in brown dwarfs are $1100\pm100$ K. Ammonia is also sensitive to gravity, but unlike CH4/CO, the NH3/N2 ratio is insensitive to mixing, which makes NH3 a potential proxy for gravity. HCN may become interesting in high gravity brown dwarfs with very strong vertical mixing. Detailed analysis of the CO-CH4 reaction network reveals that the bottleneck to CO hydrogenation goes through methanol, in partial agreement with previous work. Simple, easy to use quenching relations are derived by fitting to the complete chemistry of the full ensemble of models. These relations are valid for determining CO, CH4, NH3, HCN, and CO2 abundances in the range of self-luminous worlds we have studied but may not apply if atmospheres are strongly heated at high altitudes by processes not considered here (e.g., wave breaking).Comment: Astrophysical Journal, in press. Clarity improvements throughout and one new figure. 17 figures, 20 page

A comparison of design and model selection methods for supersaturated experiments

Various design and model selection methods are available for supersatu-rated designs having more factors than runs but little research is available ontheir comparison and evaluation. In this paper, simulated experiments areused to evaluate the use of E(s2)-optimal and Bayesian D-optimal designs,and to compare three analysis strategies representing regression, shrinkageand a novel model-averaging procedure. Suggestions are made for choosingthe values of the tuning constants for each approach. Findings include that(i) the preferred analysis is via shrinkage; (ii) designs with similar numbersof runs and factors can be effective for a considerable number of active effectsof only moderate size; and (iii) unbalanced designs can perform well. Somecomments are made on the performance of the design and analysis methodswhen effect sparsity does not hol

Model Bond albedos of extrasolar giant planets

The atmospheres of extrasolar giant planets are modeled with various effective temperatures and gravities, with and without clouds. Bond albedos are computed by calculating the ratio of the flux reflected by a planet (integrated over wavelength) to the total stellar flux incident on the planet. This quantity is useful for estimating the effective temperature and evolution of a planet. We find it is sensitive to the stellar type of the primary. For a 5 M_Jup planet the Bond albedo varies from 0.4 to 0.3 to 0.06 as the primary star varies from A5V to G2V to M2V in spectral type. It is relatively insensitive to the effective temperature and gravity for cloud--free planets. Water clouds increase the reflectivity of the planet in the red, which increases the Bond albedo. The Bond albedo increases by an order of magnitude for a 13 M_Jup planet with an M2V primary when water clouds are present. Silicate clouds, on the other hand, can either increase or decrease the Bond albedo, depending on whether there are many small grains (the former) or few large grains (the latter).Comment: 6 pages, 9 figures, uses egs.cls and epsfig.sty, submitted to Physics and Chemistry of the Earth (proceedings of the April 1998 EGS meeting in Nice, France

Analysis of Spitzer Spectra of Irradiated Planets: Evidence for Water Vapor?

Published mid infrared spectra of transiting planets HD 209458b and HD 189733b, obtained during secondary eclipse by the InfraRed Spectrograph (IRS) aboard the Spitzer Space Telescope, are predominantly featureless. In particular these flux ratio spectra do not exhibit an expected feature arising from water vapor absorption short-ward of 10 um. Here we suggest that, in the absence of flux variability, the spectral data for HD 189733b are inconsistent with 8 um-photometry obtained with Spitzer's InfraRed Array Camera (IRAC), perhaps an indication of problems with the challenging reduction of the IRS spectra. The IRAC point, along with previously published secondary eclipse photometry for HD 189733b, are in good agreement with a one-dimensional model of HD 189733b that clearly shows absorption due to water vapor in the emergent spectrum. We are not able to draw firm conclusions regarding the IRS data for HD 209458b, but spectra predicted by 1D and 3D atmosphere models fit the data adequately, without adjustment of the water abundance or reliance on cloud opacity. We argue that the generally good agreement between model spectra and IRS spectra of brown dwarfs with atmospheric temperatures similar to these highly irradiated planets lends confidence in the modeling procedure.Comment: Revised, Accepted to ApJ Letter

A non-grey analytical model for irradiated atmospheres. II: Analytical vs. numerical solutions

The recent discovery and characterization of the diversity of the atmospheres of exoplanets and brown dwarfs calls for the development of fast and accurate analytical models. We quantify the accuracy of the analytical solution derived in paper I for an irradiated, non-grey atmosphere by comparing it to a state-of-the-art radiative transfer model. Then, using a grid of numerical models, we calibrate the different coefficients of our analytical model for irradiated solar-composition atmospheres of giant exoplanets and brown dwarfs. We show that the so-called Eddington approximation used to solve the angular dependency of the radiation field leads to relative errors of up to 5% on the temperature profile. We show that for realistic non-grey planetary atmospheres, the presence of a convective zone that extends to optical depths smaller than unity can lead to changes in the radiative temperature profile on the order of 20% or more. When the convective zone is located at deeper levels (such as for strongly irradiated hot Jupiters), its effect on the radiative atmosphere is smaller. We show that the temperature inversion induced by a strong absorber in the optical, such as TiO or VO is mainly due to non-grey thermal effects reducing the ability of the upper atmosphere to cool down rather than an enhanced absorption of the stellar light as previously thought. Finally, we provide a functional form for the coefficients of our analytical model for solar-composition giant exoplanets and brown dwarfs. This leads to fully analytical pressure-temperature profiles for irradiated atmospheres with a relative accuracy better than 10% for gravities between 2.5m/s^2 and 250 m/s^2 and effective temperatures between 100 K and 3000 K. This is a great improvement over the commonly used Eddington boundary condition.Comment: Accepted in A&A, models are available at http://www.oca.eu/parmentier/nongrey or in CD

Cassini Ring Seismology as a Probe of Saturn's Interior I: Rigid Rotation

Seismology of the gas giants holds the potential to resolve long-standing questions about their internal structure and rotation state. We construct a family of Saturn interior models constrained by the gravity field and compute their adiabatic mode eigenfrequencies and corresponding Lindblad and vertical resonances in Saturn's C ring, where more than twenty waves with pattern speeds faster than the ring mean motion have been detected and characterized using high-resolution Cassini Visual and Infrared Mapping Spectrometer (VIMS) stellar occultation data. We present identifications of the fundamental modes of Saturn that appear to be the origin of these observed ring waves, and use their observed pattern speeds and azimuthal wavenumbers to estimate the bulk rotation period of Saturn's interior to be $10{\rm h}\, 33{\rm m}\, 38{\rm s}^{+1{\rm m}\, 52{\rm s}}_{-1{\rm m}\, 19{\rm s}}$ (median and 5%/95% quantiles), significantly faster than Voyager and Cassini measurements of periods in Saturn's kilometric radiation, the traditional proxy for Saturn's bulk rotation period. The global fit does not exhibit any clear systematics indicating strong differential rotation in Saturn's outer envelope.Comment: 19 pages, 6 figures, 3 tables, accepted to ApJ; a bug fix improves the fit, predicts faster bulk spin periods (Figure 4) and virtually eliminates evidence for strong radial differential rotation (Figure 5

AGRICULTURAL REVOLUTIONS IN AMERICA’S HEARTLAND: THE CORN BELT AND THE MAKING OF AMERICAN CAPITALISM

The family farm has been the foundation of America’s cheap food model. This research examines how cheap food from the Corn Belt was produced from 1840s to the late twentieth century. It investigates how the interrelationships between family farming, proletarianization-housewifization, and national and world markets configured and reconfigured. Utilizing a world-ecological framework, I argue that Illinois and Iowa, the heart of the Corn Belt, were the epicenter of two successive agricultural revolutions that fundamentally transformed world accumulation and world nature. The analysis is centered on the development of successive agricultural revolutions over the longue durée of capitalism, with the greatest attention on the nineteenth and twentieth century revolutions in the United States. At the core of the dissertation I examine what I call the ‘double dialectic’: the contradictory relationship within the agrarian household and in relation to world markets and world power. The findings of the study are historical and methodological. Historically, the Corn Belt family farm possessed a unique position within the capitalist world-economy, resulting in relative prosperity and long-term stability. Contrary to regional studies of the Corn Belt, the study provides a world-ecological framework for reconstructing the origins, development, and crisis of the Corn Belt family farm and interpreting how the production of nature, the pursuit of power, and capital accumulation constitute its development