Utilizing Astrometric Orbits to Obtain Coronagraphic Images

We present an approach for utilizing astrometric orbit information to improve the yield of planetary images and spectra from a follow-on direct detection mission. This approach is based on the notion-strictly hypothetical-that if a particular star could be observed continuously, the instrument would in time observe all portions of the habitable zone so that no planet residing therein could be missed. This strategy could not be implemented in any realistic mission scenario. But if an exoplanet's orbit is known from astrometric observation, then it may be possible to plan and schedule a sequence of imaging observations that is the equivalent of continuous observation. A series of images-optimally spaced in time-could be recorded to examine contiguous segments of the orbit. In time, all segments would be examined, leading to the inevitable detection of the planet. In this paper, we show how astrometric orbit information can be used to construct such a sequence. Using stars from astrometric and imaging target lists, we find that the number of observations in this sequence typically ranges from 2 to 7, representing the maximum number of observations required to find the planet. The probable number of observations ranges from 1.5 to 3.1. This is a dramatic improvement in efficiency over previous methods proposed for utilizing astrometric orbits. We examine how the implementation of this approach is complicated and limited by operational constraints. We find that it can be fully implemented for internal coronagraph and visual nuller missions, with a success rate approaching 100%. External occulter missions will also benefit, but to a lesser degree.Comment: 28 pages, 14 figures, submitted to PAS

Regleprudence – at OIRA and Beyond

There are significant domains of legality within the administrative state that are mostly immune from judicial review and have mostly escaped the attention of legal theorists. While administrative law generally focuses on the products of agency action as they are reviewed by the judiciary, there are important aspects of regulatory activity that are legal or law-like but rarely interrogated by systematic analysis with reference to accounts about the role and nature of law. In this Article, we introduce a category of analysis we call regleprudence, a sibling of jurisprudence and legisprudence. Once we explore some regleprudential norms, we delve into one case study – the Office of Information and Regulatory Affairs and the legal work it undertakes through regulatory review – and gesture at how more general attention to regleprudence can improve our understanding of important corners of the Executive Branch

Regleprudence – at OIRA and Beyond

There are significant domains of legality within the administrative state that are mostly immune from judicial review and have mostly escaped the attention of legal theorists. While administrative law generally focuses on the products of agency action as they are reviewed by the judiciary, there are important aspects of regulatory activity that are legal or law-like but rarely interrogated by systematic analysis with reference to accounts about the role and nature of law. In this Article, we introduce a category of analysis we call regleprudence, a sibling of jurisprudence and legisprudence. Once we explore some regleprudential norms, we delve into one case study – the Office of Information and Regulatory Affairs and the legal work it undertakes through regulatory review – and gesture at how more general attention to regleprudence can improve our understanding of important corners of the Executive Branch

Exploiting multi-agent system technology within an autonomous regional active network management system

This paper describes the proposed application of multi-agent system (MAS) technology within AuRA-NMS, an autonomous regional network management system currently being developed in the UK through a partnership between several UK universities, distribution network operators (DNO) and a major equipment manufacturer. The paper begins by describing the challenges facing utilities and why those challenges have led the utilities, a major manufacturer and the UK government to invest in the development of a flexible and extensible active network management system. The requirements the utilities have for a network automation system they wish to deploy on their distribution networks are discussed in detail. With those requirements in mind the rationale behind the use of multi-agent systems (MAS) within AuRA-NMS is presented and the inherent research and design challenges highlighted including: the issues associated with robustness of distributed MAS platforms; the arbitration of different control functions; and the relationship between the ontological requirements of Foundation for Intelligent Physical Agent (FIPA) compliant multi-agent systems, legacy protocols and standards such as IEC 61850 and the common information model (CIM)

Ancient Cosmic Dust from Triassic Halite

We describe the discovery of fossil micrometeorites in ancient Triassic rock salt; the first to be found in salt and the oldest complete micrometeorites found to date. We present an estimated flux rate of micrometeorites to Earth at this time

Two Higgs doublets to explain the excesses pp→γγ(750 GeV)pp\rightarrow \gamma\gamma(750\ {\rm GeV}) and h→τ±μ∓h \to \tau^\pm \mu^\mp

The two Higgs doublet model emerges as a minimal scenario in which to address, at the same time, the $\gamma\gamma$ excess at 750 GeV and the lepton flavour violating decay into $\tau^\pm \mu^\mp$ of the 125 GeV Higgs boson. The price to pay is additional matter to enhance the $\gamma\gamma$ rate, and a peculiar pattern for the lepton Yukawa couplings. We add TeV scale vector-like fermions and find parameter space consistent with both excesses, as well as with Higgs and electroweak precision observables.Comment: 15 pages, 1 figure; v2: discussion of tau-->mu gamma added, leading to an additional constraint. v3: references added, figure 1 recovered and figure 2 adde

Effect of cryogenic irradiation on NERVA structural alloys

Several alloys (Hastelloy X, AISI 347, A-286 bolts, Inconel 718, Al 7039-T63 and Ti-5Al-2.5Sn ELI) were irradiated in liquid nitrogen (140 R) to neutron fluences between 10 to the 17th power and 10 to the 19th power nvt (E greater than 1.0 Mev). After irradiation, tensile properties were obtained in liquid nitrogen without permitting any warmup except for some specimens which were annealed at 540 R. The usual trend of radiation damage typical for materials irradiated at and above room temperature was observed, such as an increase in strength and decrease in ductility. However, the damage at 140 R was greater because this temperature prevented the annealing of radiation-induced defects which occurs above 140 R

Sulfate and MSA in the air and snow on the Greenland Ice Sheet

Sulfate and methanesulfonic acid (MSA) concentrations in aerosol, surface snow, and snowpit samples have been measured at two sites on the Greenland Ice Sheet. Seasonal variations of the concentrations observed for these chemical species in the atmosphere are reproduced in the surface snow and preserved in the snowpit sequence. The amplitude of the variations over a year are smaller in the snow than in the air, but the ratios of the concentrations are comparable. The seasonal variations for sulfate are different at the altitude of the Ice Sheet compared to those observed at sea level, with low concentrations in winter and short episodes of elevated concentrations in spring. In contrast, the variations in concentrations of MSA are similar to those measured at sea level, with a first sequence of elevated concentrations in spring and another one during summer, and a winter low resulting from low biogenic production. The ratio MSA/sulfate clearly indicates the influence of high-latitude sources for the summer maximum of MSA, but the large impact of anthropogenic sulfate precludes any conclusion for the spring maximum. The seasonal pattern observed for these species in a snowpit sampled according to stratigraphy indicates a deficit in the accumulation of winter snow at the summit of the Greenland Ice Sheet, in agreement with some direct observations. A deeper snowpit covering the years 1985–1992 indicates the consistency of the seasonal pattern for MSA over the years, which may be linked to transport and deposition processes

Erysipelas: with special reference to old and new treatment

Much has been written and continues to be written regarding the treatment of erysipelas, each new remedy enjoying a passing popularity, only to be discarded in favour of the next. The mere multiplicity of methods itself testifies to their inefficacy, or their lack of universal applicability, and indicates the need for further experiment.In a disease such as erysipelas, which is so uncertain in its duration, it is extremely difficult to assess the value of any particular mode of treatment, and still more difficult to construct convincing statistics. "Control cases" are of necessity under Suspicion, as no two cases can be expected to progress alike when untreated.In some of the cases under consideration, the disappearance of signs and symptoms may awell have been post hoc and not propter hoc; in others, in which it was possible to tackle only one section of the spreading edge, the constitutional disturbance continued although the local treatment appeared to be Successful where it was applied; in others the erysipelas was a complication of another infection, and any amelioration of symptoms which might have accrued from cessation of the former was obscu4 by a continuance of the latter

A comparison of soil moisture characteristics predicted by the Arya-Paris model with laboratory-measured data

Soil moisture characteristics predicted by the Arya-Paris model were compared with the laboratory measured data for 181 New Jersey soil horizons. For a number of soil horizons, the predicted and the measured moisture characteristic curves are almost coincident; for a large number of other horizons, despite some disparity, their shapes are strikingly similar. Uncertainties in the model input and laboratory measurement of the moisture characteristic are indicated, and recommendations for additional experimentation and testing are made