Detection of molecular microwave transitions in the 3 mm wavelength range in comet Kohoutek (1973f)

Observations of comet Kohoutek made with a 3-mm line receiver mounted on the 11-m NRAO radio dish at Kitt Peak are presented. The detection of line transitions of hydrogen cyanide and methyl cyanide is reported and discussed along with the variability of neutral gas jets. Microwave transitions in molecules of cometary origin are also examined

Vanadium Oxytrichloride as a Solvent

Vanadium oxytrichloride is a liquid from below -15° to about 125°. This is an excellent range for a solvent. The liquid is light yellow in color and has a density of about 1.8. It is easily hydrolyzed. The solubilities of about 80 substances have been determined. No inorganic compound is more than very sparingly soluble in vanadium oxytrichloride. Elements of the chlorine and sulfur families are soluble. Most organic compounds are readily soluble

A Scalable Asynchronous Distributed Algorithm for Topic Modeling

Learning meaningful topic models with massive document collections which contain millions of documents and billions of tokens is challenging because of two reasons: First, one needs to deal with a large number of topics (typically in the order of thousands). Second, one needs a scalable and efficient way of distributing the computation across multiple machines. In this paper we present a novel algorithm F+Nomad LDA which simultaneously tackles both these problems. In order to handle large number of topics we use an appropriately modified Fenwick tree. This data structure allows us to sample from a multinomial distribution over $T$ items in $O(\log T)$ time. Moreover, when topic counts change the data structure can be updated in $O(\log T)$ time. In order to distribute the computation across multiple processor we present a novel asynchronous framework inspired by the Nomad algorithm of \cite{YunYuHsietal13}. We show that F+Nomad LDA significantly outperform state-of-the-art on massive problems which involve millions of documents, billions of words, and thousands of topics

The Use of Linear Elastic Fracture Mechanics in Viking Pressure Vessel Design

Fracture mechanics methodology has developed rapidly over the past 10 years. Although not as yet sufficiently developed for the treatment of complex structures such as aircraft, it is believed that fracture mechanics can provide a sound basis for the design of simple structures such as pressure bottles or tanks. Consequently, the Viking Project has adopted its use for design of all pressure vessels on the Viking spacecraft to assure the long life under sustained pressure necessary for the trip to Mars

A Spectral Line Survey of Selected 3 mm Bands Toward Sagittarius B2(N-LMH) Using the NRAO 12 Meter Radio Telescope and the BIMA Array I. The Observational Data

We have initiated a spectral line survey, at a wavelength of 3 millimeters, toward the hot molecular core Sagittarius B2(N-LMH). This is the first spectral line survey of the Sgr B2(N) region utilizing data from both an interferometer (BIMA Array) and a single-element radio telescope (NRAO 12 meter). In this survey, covering 3.6 GHz in bandwidth, we detected 218 lines (97 identified molecular transitions, 1 recombination line, and 120 unidentified transitions). This yields a spectral line density (lines per 100 MHz) of 6.06, which is much larger than any previous 3 mm line survey. We also present maps from the BIMA Array that indicate that most highly saturated species (3 or more H atoms) are products of grain chemistry or warm gas phase chemistry. Due to the nature of this survey we are able to probe each spectral line on multiple spatial scales, yielding information that could not be obtained by either instrument alone.Comment: 35 pages, 15 figures, to be published in The Astrophysical Journa

Hartree-Fock-Bogoliubov Model and Simulation of Attractive and Repulsive Bose-Einstein Condensates

We describe a model of dynamic Bose-Einstein condensates near a Feshbach resonance that is computationally feasible under assumptions of spherical or cylindrical symmetry. Simulations in spherical symmetry approximate the experimentally measured time to collapse of an unstably attractive condensate only when the molecular binding energy in the model is correct, demonstrating that the quantum fluctuations and atom-molecule pairing included in the model are the dominant mechanisms during collapse. Simulations of condensates with repulsive interactions find some quantitative disagreement, suggesting that pairing and quantum fluctuations are not the only significant factors for condensate loss or burst formation. Inclusion of three-body recombination was found to be inconsequential in all of our simulations, though we do not consider recent experiments [1] conducted at higher densities

The Hudson Bay Lithospheric Experiment (HuBLE) : Insights into Precambrian Plate Tectonics and the Development of Mantle Keels

The UK component of HuBLE was supported by Natural Environment Research Council (NERC) grant NE/F007337/1, with financial and logistical support from the Geological Survey of Canada, Canada–Nunavut Geoscience Office, SEIS-UK (the seismic node of NERC), and First Nations communities of Nunavut. J. Beauchesne and J. Kendall provided invaluable assistance in the field. Discussions with M. St-Onge, T. Skulski, D. Corrigan and M. Sanborne-Barrie were helpful for interpretation of the data. D. Eaton and F. A. Darbyshire acknowledge the Natural Sciences and Engineering Research Council. Four stations on the Belcher Islands and northern Quebec were installed by the University of Western Ontario and funded through a grant to D. Eaton (UWO Academic Development Fund). I. Bastow is funded by the Leverhulme Trust. This is Natural Resources Canada Contribution 20130084 to its Geomapping for Energy and Minerals Program. This work has received funding from the European Research Council under the European Unions Seventh Framework Programme (FP7/2007-2013)/ERC Grant agreement no. 240473 ‘CoMITAC’.Peer reviewedPublisher PD

Energy Siting in Utah: A Programming Model

Using a conceptual model of a multiple-product firm, the necessary conditions for an optimal input and output allocation were determined for a region constrained by resource availabilities and/or policy constraints. A linear programming model was developed to deteremine the optimal allocation of water between agricultural and coal-fired electrical generating entities as well as the trade offs which could occur if electrical generation were increased. Other areas of potential trade offs such as coal source restrictions and air quality regualtions were also examined. Coal mining and transportation costs were included as were SO2, Nox, and particulate emission rates on a coal and plant basis. Few trade offs between electrical power generation and irrigated agriculture were noted. However, substantial changes within the energy sector were discovered as coal capacities and air quality energy sector were discovered as coal capacities and air quality standards were changed. Net revenues declined sharply as air costs after and/or pollution and coal capacity restrictions were imposed and/or increased. It was determined that substantial changes in regional economic activity occurred as a result of these restrictions on development