Possible identifications of the 3.4 micrometer feature

A feature at 3.4 micrometer was first detected in Comet Halley by the IKS spectrometer on board the Vega 1 probe; and subsequently from the ground. The feature has since been reported in Comet Wilson. The presence of the feature is of considerable interest for a number of reasons. First, it may represent the detection of a new parent molecule, and when combined with data from Giotto and Vega yield new information on cometary chemistry and the early solar system composition. Secondly, it may represent a link to the interstellar medium, the feature corresponds in wavelength and shape with an interstellar feature seen in absorption in a luminous star, towards the Galactic center known as GC-IRS7. The feature in turn is thought to be related with a growing family of unidentified infrared emission features seen in stellar objects, planetary nebulae, reflection nebulae, HII regions and extra galactic sources. These features occur at wavelengths 3.3, 3.4, 3.5, 6.2, 7.7, 8.6, and 11.25 micrometers. Further identification theory is given

Operational criteria used by professional social workers to assess relationship

Thesis (M.S.)--Boston Universit

New methods for the enantiomeric excess determination using NMR

The synthesis of enantiomerically pure compounds is an important objective of the organic chemistry. Especially in the field of medicine and pesticides, mostly one enantiomer is responsible for the biological activity. Certain examples are known where the other enantiomer is more than isomerical balast, and its presence gives rise to side-effects. It is not surprising that the regulatory authorities in Europe and the United States usually impose that chiral compounds are marketed as single enantiomers. Growing interest and improvement in enantioselective synthesis leads to an increased demand for accurate, reliable and convenient methods of measuring the enantiomeric composition. A large number of methods for the determination of the enantiomeric excess (e.e.) of regardless which chiral substrate have been developed over the years. A popular, accurate, and moreover, fast method for the determination of the enantiomeric composition is to make use of NMR techniques (Nuclear Magnetic Resonance). This thesis describes the research carried out towards the development of new methods for enantiorneric excess determination of amino acids and not naturally occuring α-alkylated amino acids by means of NMR techniques.

Topology Control in VANET and Capacity Estimation

International audienceSome safety applications using VANET exchange a large amount of data, and consequently require an important network capacity. In this paper, we focus on extended perception map applications, that use information from local and distant sensors to offer driving assistance (autonomous driving, collision warning, etc). Extended perception requires a high bandwidth that might not be available in practice in classical IEEE 802.11p ad hoc networks. Therefore, we propose an adaptive power control algorithm optimized for this particular application. We show through an analytical model and a large set of simulations that the network capacity is then significantly increased

A Unified View on Solving Objective Mismatch in Model-Based Reinforcement Learning

Model-based Reinforcement Learning (MBRL) aims to make agents more sample-efficient, adaptive, and explainable by learning an explicit model of the environment. While the capabilities of MBRL agents have significantly improved in recent years, how to best learn the model is still an unresolved question. The majority of MBRL algorithms aim at training the model to make accurate predictions about the environment and subsequently using the model to determine the most rewarding actions. However, recent research has shown that model predictive accuracy is often not correlated with action quality, tracing the root cause to the \emph{objective mismatch} between accurate dynamics model learning and policy optimization of rewards. A number of interrelated solution categories to the objective mismatch problem have emerged as MBRL continues to mature as a research area. In this work, we provide an in-depth survey of these solution categories and propose a taxonomy to foster future research

The Australian Space Eye: studying the history of galaxy formation with a CubeSat

The Australian Space Eye is a proposed astronomical telescope based on a 6U CubeSat platform. The Space Eye will exploit the low level of systematic errors achievable with a small space based telescope to enable high accuracy measurements of the optical extragalactic background light and low surface brightness emission around nearby galaxies. This project is also a demonstrator for several technologies with general applicability to astronomical observations from nanosatellites. Space Eye is based around a 90 mm aperture clear aperture all refractive telescope for broadband wide field imaging in the i and z bands.Comment: 19 pages, 14 figures, submitted for publication as Proc. SPIE 9904, 9904-56 (SPIE Astronomical Telescopes & Instrumentation 2016

Report of the panel on international programs

The panel recommends that NASA participate and take an active role in the continuous monitoring of existing regional networks, the realization of high resolution geopotential and topographic missions, the establishment of interconnection of the reference frames as defined by different space techniques, the development and implementation of automation for all ground-to-space observing systems, calibration and validation experiments for measuring techniques and data, the establishment of international space-based networks for real-time transmission of high density space data in standardized formats, tracking and support for non-NASA missions, and the extension of state-of-the art observing and analysis techniques to developing nations