1,104 research outputs found

    Unified Models of Molecular Emission from Class 0 Protostellar Outflow Sources

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    Low mass star-forming regions are more complex than the simple spherically symmetric approximation that is often assumed. We apply a more realistic infall/outflow physical model to molecular/continuum observations of three late Class 0 protostellar sources with the aims of (a) proving the applicability of a single physical model for all three sources, and (b) deriving physical parameters for the molecular gas component in each of the sources. We have observed several molecular species in multiple rotational transitions. The observed line profiles were modelled in the context of a dynamical model which incorporates infall and bipolar outflows, using a three dimensional radiative transfer code. This results in constraints on the physical parameters and chemical abundances in each source. Self-consistent fits to each source are obtained. We constrain the characteristics of the molecular gas in the envelopes as well as in the molecular outflows. We find that the molecular gas abundances in the infalling envelope are reduced, presumably due to freeze-out, whilst the abundances in the molecular outflows are enhanced, presumably due to dynamical activity. Despite the fact that the line profiles show significant source-to-source variation, which primarily derives from variations in the outflow viewing angle, the physical parameters of the gas are found to be similar in each core.Comment: MNRAS 12 pages, 16 figure

    Cavan Protestants in an age of upheaval, 1919-22

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    Broadly speaking, this is a study of the Protestant population of County Cavan in a time of social and political upheaval. Chapter one is concerned with identifying Cavan’s Protestants as a group, both politically and culturally Chapter two, given the cultural and political identity of the county’s Protestants, shows how this group reacted and adapted to the political changes of the years 1919-22. It was found that Protestantism, after a slight realignment, largely accepted Ireland’s new position regarding Britain and despite that fact that unionism as a political force was greatly diminished, the values that had given rise to that unionism remained relatively intact. After identifying the group that existed in ideological opposition to Protestantism, namely Catholicism or nationalism, chapter three sought to see if these two groups were impermeable to each other, or if all their relations were marked by hostility. It was found that ideology was muted by the practicality of each group living side-to-side together, with both peoples showing mutual respect for each other. The study concludes that, while Cavan’s Protestants accepted the Irish Free State, they remained a specific cultural/political group within the county as those beliefs that had given them their unionist tendencies were not put to rest, despite the great weakening of Irelands relationship with Great Britain

    Observations and radiative transfer modelling of a massive dense cold core in G333

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    Cold massive cores are one of the earliest manifestations of high mass star formation. Following the detection of SiO emission from G333.125-0.562, a cold massive core, further investigations of the physics, chemistry and dynamics of this object has been carried out. Mopra and NANTEN2 molecular line profile observations, Australia Telescope Compact Array (ATCA) line and continuum emission maps, and Spitzer 24 and 70 \mum images were obtained. These new data further constrain the properties of this prime example of the very early stages of high mass star formation. A model for the source was constructed and compared directly with the molecular line data using a 3D molecular line transfer code - MOLLIE. The ATCA data reveal that G333.125-0.562 is composed of two sources. One of the sources is responsible for the previously detected molecular outflow and is detected in the Spitzer 24 and 70 \mum band data. Turbulent velocity widths are lower than other more active regions of G333 which reflects the younger evolutionary stage and/or lower mass of this core. The molecular line modelling requires abundances of the CO isotopes that strongly imply heavy depletion due to freeze-out of this species onto dust grains. The principal cloud is cold, moderately turbulent and possesses an outflow which indicates the presence of a central driving source. The secondary source could be an even less evolved object as no apparent associations with continuum emissions at (far-)infrared wavelengths.Comment: 10 pages, accepted to MNRA

    Franchise Law Compliance: Before the Logo Hits the Streets

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    The increasing popularity of franchising as a method of doing business has led to substantial regulation aimed at safeguarding existing and potential franchisees. This article discusses the registration and disclosure requirements of the Maryland Franchise Act The authors analyze the steps to be taken by a practitioner in achieving compliance with the franchise laws in Maryland and in jurisdictions governed by statutes similar to that of Maryland

    Franchise Law Compliance: Before the Logo Hits the Streets

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    The increasing popularity of franchising as a method of doing business has led to substantial regulation aimed at safeguarding existing and potential franchisees. This article discusses the registration and disclosure requirements of the Maryland Franchise Act The authors analyze the steps to be taken by a practitioner in achieving compliance with the franchise laws in Maryland and in jurisdictions governed by statutes similar to that of Maryland

    A systematic review of interventions for Hispanic women with or at risk of Gestational diabetes mellitus (GDM)

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    © 2017 Elsevier B.V. Background and objective Gestational Diabetes Mellitus (GDM) is a serious health concern for pregnant women, with Hispanic women at particular risk for developing the condition. The aim of this review was to critically examine GDM intervention programs for Hispanic women, in the United States of America (US). Methods English and Spanish electronic databases were searched for relevant studies published between 1995 and 2015. Eligible study designs included randomized controlled trial, pre/post-test and quasi experimental methods. Results Findings indicated that there was a dearth of literature reporting on GDM interventions for Hispanic women and just seven papers met inclusion criteria. These seven studies were included in the review and they reported on interventions for: (1) pregnant women at high risk of developing GDM; (2) pregnant women with GDM. Results suggest that a combination of intensive counselling over a prolonged period of time, together with a low calorie, possibly low glycemic index diet, produces best results. Conclusion The review found that intensive nutritional counselling approaches which promote low calorie/low GI diets appear to be most effective in BGL management in this population. Interventions that are delivered in Spanish and culturally tailored may be more acceptable to participants. More research is needed to develop suitable interventions to improve GDM management among Hispanic women

    Commutativity and the emergence of classical objectivity

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    We examine how the ability of a system to redundantly proliferate relevant information about its pointer states is affected when it is coupled to multiple baths. To this end, we consider a system in contact with two baths: one—termed the accessible environment —which, on its own, induces a pure dephasing mechanism on the state of the system and satisfies the conditions for classical objectivity to be established. The second environment, which we dub as inaccessible, affects the system in two physically relevant ways. Firstly, we consider an interaction that commutes with the Hamiltonian describing the interaction between system and accessible bath. It thus also gives rise to dephasing of the system, albeit on different time scales. Secondly, we consider a thermalising interaction, which does not commute with the system-accessible environment Hamiltonian. While the former still allows the system to redundantly encode its state into the accessible environment, the latter degrades the correlations, eventually destroying them in the long-time limit, and thus leads to a loss of the conditions necessary for classical objectivity to be established. This sheds light on the role that commutativity between the various system-bath interaction terms plays when establishing the conditions for classical objectivity to be supported

    PSPSO: A package for parameters selection using particle swarm optimization

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    This paper reports a high-level python package for selecting machine learning algorithms and ensembles of machine learning algorithms parameters by using the particle swarm optimization (PSO) algorithm named PSPSO. The first version of PSPSO supports four algorithms: Support Vector Machine (SVM), Multi-Layer Perceptron (MLP), Extreme Gradient Boosting (XGBoost) and Gradient Boosting Decision Trees (GBDT). PSPSO provides an easy framework for building machine learning algorithms using PSO and a new platform for researchers to investigate their selection methods. In addition, it provides a basis for establishing new selection ideas and can be easily extended to support other algorithms

    Electrical and physical characterization of the Al<sub>2</sub>O<sub>3</sub>/ <i>p</i>-GaSb interface for 1%, 5%, 10%, and 22% (NH<sub>4</sub>)<sub>2</sub>S surface treatments

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    In this work, the impact of ammonium sulfide ((NH&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;S) surface treatment on the electrical passivation of the Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;/ &lt;i&gt;p&lt;/i&gt;-GaSb interface is studied for varying sulfide concentrations. Prior to atomic layer deposition of Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, GaSb surfaces were treated in 1%, 5%, 10%, and 22% (NH&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;S solutions for 10 min at 295 K. The smallest stretch-out and flatband voltage shifts coupled with the largest capacitance swing, as indicated by capacitance-voltage (&lt;i&gt;CV&lt;/i&gt;) measurements, were obtained for the 1% treatment. The resulting interface defect trap density (&lt;i&gt;D&lt;/i&gt;&lt;sub&gt;it&lt;/sub&gt;) distribution showed a minimum value of 4 x 10&lt;sup&gt;12&lt;/sup&gt; cm&lt;sup&gt;-2&lt;/sup&gt;eV&lt;sup&gt;-1&lt;/sup&gt; at &lt;i&gt;E&lt;/i&gt;&lt;sub&gt;v&lt;/sub&gt; + 0.27 eV. Transmission electron microscopy and atomic force microscopy examination revealed the formation of interfacial layers and increased roughness at the Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;/ &lt;i&gt;p&lt;/i&gt;-GaSb interface of samples treated with 10% and 22% (NH&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;S. In combination, these effects degrade the interface quality as reflected in the &lt;i&gt;CV&lt;/i&gt; characteristics
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