1,250 research outputs found
Deed, property transfer, Robert Morton and James W. Dunnington to Henry B. Scott and Patrick Jackson, 1840
Friends of Hot Jupiters II: No Correspondence Between Hot-Jupiter Spin-Orbit Misalignment and the Incidence of Directly Imaged Stellar Companions
Multi-star systems are common, yet little is known about a stellar
companion's influence on the formation and evolution of planetary systems. For
instance, stellar companions may have facilitated the inward migration of hot
Jupiters towards to their present day positions. Many observed short period gas
giant planets also have orbits that are misaligned with respect to their star's
spin axis, which has also been attributed to the presence of a massive outer
companion on a non-coplanar orbit. We present the results of a multi-band
direct imaging survey using Keck NIRC2 to measure the fraction of short period
gas giant planets found in multi-star systems. Over three years, we completed a
survey of 50 targets ("Friends of Hot Jupiters") with 27 targets showing some
signature of multi-body interaction (misaligned or eccentric orbits) and 23
targets in a control sample (well-aligned and circular orbits). We report the
masses, projected separations, and confirmed common proper motion for the 19
stellar companions found around 17 stars. Correcting for survey incompleteness,
we report companion fractions of , , and
in our total, misaligned/eccentric, and control samples, respectively. This
total stellar companion fraction is larger than the fraction of
field stars with companions approximately AU. We observe no
correlation between misaligned/eccentric hot Jupiter systems and the incidence
of stellar companions. Combining this result with our previous radial velocity
survey, we determine that of hot Jupiters are part of
multi-planet and/or multi-star systems.Comment: typos and references updated; 25 pages, 7 figures and 10 tables,
accepted for publication in Ap
Chromospherically Active Stars. X. Spectroscopy and Photometry of HD 212280
The system HD 212280 is a chromospherically active double lined spectroscopic binary with an orbital period of 45.284 days and an eccentricity of 0.50. The spectrum is composite with spectral types of G8 IV and F5-8 V for the components. An estimated inclination of 78 +/- 8 deg results in masses of 1.7 and 1.4 solar mass for the G subgiant and mid-F star, respectively. The distance to the system is estimated to be 112 pc. Photometric observations obtained between 1987 November and 1992 June reveal that HD 212280 is a newly identified variable star with a V amplitude of about 0.15 mag and a mean period of 29.46 days. Our V data were divided into 11 sets and in all but one case two spots were required to fit the data. Lifetimes of 650 days and a minimum of 1350 days have been determined for two of the four spots. The differential rotation coefficient of 0.05 is relatively small. The age of the system is about 1.9 X 10 exp 9 yrs. The G subgiant is rotating slower than pseudosynchronously while the F-type star is rotating faster
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NSNFP Activities in Support of Repository Licensing for Disposal of DOE SNF
The U.S. Department of Energy (DOE) Office of Civilian Radioactive Waste Management is in the process of preparing the Yucca Mountain license application for submission to the Nuclear Regulatory Commission as the nation’s first geologic repository for spent nuclear fuel (SNF) and high-level waste. Because the DOE SNF will be part of the license application, there are various components of the license application that will require information relative to the DOE SNF. The National Spent Nuclear Fuel Program (NSNFP) is the organization that directs the research, development, and testing of treatment, shipment, and disposal technologies for all DOE SNF. This report documents the work activities conducted by the NSNFP and discusses the relationship between these NSNFP technical activities and the license application. A number of the NSNFP activities were performed to provide risk insights and understanding of DOE SNF disposal as well as to prepare for anticipated questions from the regulatory agency
Single frequency erbium fiber external cavity semiconductor laser
A novel external cavity configuration for stable single frequency operation of the semiconductor laser is demonstrated. By using an erbium doped fiber as the external cavity, longitudinal mode-hopping is suppressed, ensuring single frequency operation. Employing a 3m long fiber cavity, resolution-limited optical linewidths of a kHz are obtained.[This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing.
Ernst Freund as Precursor of the Rational Study of Corporate Law
Gindis, David, Ernst Freund as Precursor of the Rational Study of Corporate Law (October 27, 2017). Journal of Institutional Economics, Forthcoming. Available at SSRN: https://ssrn.com/abstract=2905547, doi: https://dx.doi.org/10.2139/ssrn.2905547The rise of large business corporations in the late 19th century compelled many American observers to admit that the nature of the corporation had yet to be understood. Published in this context, Ernst Freund's little-known The Legal Nature of Corporations (1897) was an original attempt to come to terms with a new legal and economic reality. But it can also be described, to paraphrase Oliver Wendell Holmes, as the earliest example of the rational study of corporate law. The paper shows that Freund had the intuitions of an institutional economist, and engaged in what today would be called comparative institutional analysis. Remarkably, his argument that the corporate form secures property against insider defection and against outsiders anticipated recent work on entity shielding and capital lock-in, and can be read as an early contribution to what today would be called the theory of the firm.Peer reviewe
Anisotropic permeability in deterministic lateral displacement arrays
We uncover anisotropic permeability in microfluidic deterministic lateral
displacement (DLD) arrays. A DLD array can achieve high-resolution bimodal
size-based separation of microparticles, including bioparticles, such as cells.
For an application with a given separation size, correct device operation
requires that the flow remains at a fixed angle to the obstacle array. We
demonstrate via experiments and lattice-Boltzmann simulations that subtle array
design features cause anisotropic permeability. Anisotropic permeability
indicates the microfluidic array's intrinsic tendency to induce an undesired
lateral pressure gradient. This can cause an inclined flow and therefore local
changes in the critical separation size. Thus, particle trajectories can become
unpredictable and the device useless for the desired separation task.
Anisotropy becomes severe for arrays with unequal axial and lateral gaps
between obstacle posts and highly asymmetric post shapes. Furthermore, of the
two equivalent array layouts employed with the DLD, the rotated-square layout
does not display intrinsic anisotropy. We therefore recommend this layout over
the easier-to-implement parallelogram layout. We provide additional guidelines
for avoiding adverse effects of anisotropy on the DLD.Comment: 13 pages, 10 figures, 1 table, DLD, particle separation,
microfluidics, anisotropic permeabilit
Friends of Hot Jupiters. I. A Radial Velocity Search for Massive, Long-Period Companions to Close-In Gas Giant Planets
In this paper we search for distant massive companions to known transiting hot Jupiters that may have influenced the dynamical evolution of these systems. We present new radial velocity observations for a sample of 51 hot Jupiters obtained using the Keck HIRES instrument, and use these observations to search for long-term radial velocity accelerations. We find new, statistically significant accelerations in seven systems, including: HAT-P-10, HAT-P-20, HAT-P-22, HAT-P-29, HAT-P-32, WASP-10, and XO-2. We combine our radial velocity fits with Keck NIRC2 AO imaging data to place constraints on the allowed masses and orbital periods of the companions. The estimated masses of the companions range between 1-500 M_(Jup), with orbital semi-major axes typically between 1-75 AU. A significant majority of the companions detected by our survey are constrained to have minimum masses comparable to or larger than those of the short-period hot Jupiters in these systems, making them candidates for influencing the orbital evolution of the inner hot Jupiters. They also appear to occur preferentially in systems with more metal-rich host stars, and with typical orbital separations that are larger than those of multi-planet systems without hot Jupiters. We estimate a total occurrence rate of 55% +11% / -10% for companions with masses between 1-13 M_(Jup) and orbital semi-major axes between 1-20 AU in our sample. We find no statistically significant difference between the frequency of companions in hot Jupiter systems with misaligned or eccentric orbits and those with well-aligned, circular orbits. We combine our expanded sample of radial velocity measurements with constraints from transit and secondary eclipse observations to provide improved measurements of the physical and orbital characteristics of all of the hot Jupiters included in our survey
The Frequency of Hot Jupiters Orbiting Nearby Solar-Type Stars
We determine the fraction of F, G, and K dwarfs in the Solar Neighborhood
hosting hot jupiters as measured by the California Planet Survey from the Lick
and Keck planet searches. We find the rate to be 1.2\pm0.38%, which is
consistent with the rate reported by Mayor et al. (2011) from the HARPS and
CORALIE radial velocity surveys. These numbers are more than double the rate
reported by Howard et al. (2011) for Kepler stars and the rate of Gould et al.
(2006) from the OGLE-III transit search, however due to small number statistics
these differences are of only marginal statistical significance. We explore
some of the difficulties in estimating this rate from the existing radial
velocity data sets and comparing radial velocity rates to rates from other
techniques.Comment: 6pp emulateapj, 2 tables, ApJ accepte
Science in neo-Victorian poetry
This article considers the work of three contemporary poets and their engagement, in verse, with Victorian science. Beginning with the outlandish ‘theories’ of Mick Imlah’s ‘The Zoologist’s Bath’ (1983), it moves on to two works of biografiction – Anthony Thwaite’s poem ‘At Marychurch’ (1980), which outlines Philip Henry Gosse’s doomed attempts to unite evolution and Christianity, and Ruth Padel’s Darwin: A Life in Poems (2009). Starting off with John Glendening’s idea that science in neo-Victorian fiction, if fully embraced, provides an opportunity for self-revelation to characters, this article explores the rather less happy resolutions of each of these poems, while in addition discussing the ways in which these poems perform the formal changes and mutability discussed within them
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