A Long-Term Study of Ultraluminous X-ray Sources in NGC 891

We perform empirical fits to the Chandraand XMM-Newton spectra of three ultraluminous X-ray sources (ULXs) in the edge-on spiral galaxy NGC 891, monitoring the region over a 17-year time window. One of these sources was visible since the early 1990s with ROSAT and was observed multiple times with Chandra and XMM-Newton. Another was visible since 2011. We build upon prior analyses of these sources by analyzing all available data at all epochs. Where possible Chandra data is used, since its superior spatial resolution allows for more effective isolation of the emission from each individual source, thus providing a better determination of their spectral properties. We also identify a new transient ULX, CXOU J022230.1+421937, which faded from view over the course of a two month period from Nov 2016 to Jan 2017. Modeling of each source at every epoch was conducted using six different models ranging from thermal bremsstrahlung to accretion disk models. Unfortunately, but as is common with many ULXs, no single model yielded a much better fit than the others. The two known sources had unabsorbed luminosities that remained fairly consistent over five or more years. Various possibilities for the new transient ULX are explored.

Deriving CO2 emissions of localized sources from OCO-3 XCO2 and TROPOMI NO2 satellite data

<p>Carbon dioxide (CO<sub>2</sub>) is the most important anthropogenic greenhouse gas and the main driver of global warming. Its atmospheric concentrations have risen more than 40% since pre-industrial times. Almost 90% of this increase results from fossil fuel combustion, emitting CO<sub>2</sub> predominantly from localized sources. In order to track the reduction efforts to comply with the objectives of the Paris Agreement, emissions need to be monitored. For this purpose, bottom-up emission estimates are regularly reported in the national greenhouse gas inventories. Top-down observation-based estimates can complement and verify these inventories. Satellite observations have an important role in this context, since they can provide global information.</p> <p>Due to CO<sub>2</sub>'s long lifetime and large fluxes of natural origin, the column-average concentrations resulting from anthropogenic emissions from individual source points are usually small compared to the background concentration, and these enhancements are often barely larger than the satellite's instrument noise. This makes the detection of CO<sub>2</sub> emission plumes and the quantification of anthropogenic fluxes challenging.</p> <p>NO<sub>2</sub> is co-emitted with CO<sub>2</sub> in the combustion of fossil fuels. It has a much shorter lifetime, and as a result, its vertical column densities can exceed background values and sensor noise by orders of magnitude in emission plumes. This makes it a suitable tracer for recently emitted CO<sub>2</sub>.</p> <p>The objective of this study is to quantify the CO<sub>2</sub> emissions from localized sources such as power plants by using XCO<sub>2</sub> (the column-averaged dry air mole fraction of CO<sub>2</sub>) retrievals from the Orbiting Carbon Observatory 3 (OCO-3) in its snapshot area mode. Our presentation describes a plume detection method using NO<sub>2</sub> as a tracer for recently emitted CO<sub>2</sub> and an inversion technique to quantify CO<sub>2</sub> emissions from detected CO<sub>2</sub> plumes.</p>

Development of Emission Factor Equations for Surface Mining Activities: The Case of the Stacker

In surface mines, various activities (e.g., excavations, loading and unloading of material, moving vehicles on unpaved haul roads, etc.) represent significant sources of fugitive dust. The estimation of dust generation from each individual source is a basic step in planning and implementation decision-making systems regarding the air quality of the surrounding area. Typically, this can be obtained by using emission factor or prediction-type equations. A detailed study was carried out at four surface lignite mines to determine PM emission factors and to develop the prediction-type equations of various surface mining activities. In this work, the data, method and results referring to the stacker, one of and the significant fugitive dust emissions source in mining operations are presented and analyzed.

A Framework for Estimating Migrant Stocks Using Digital Traces and Survey Data: An Application in the United Kingdom

An accurate estimation of international migration is hampered by a lack of timely and comprehensive data, and by the use of different definitions and measures of migration in different countries. In an effort to address this situation, we complement traditional data sources for the United Kingdom with social media data: our aim is to understand whether information from digital traces can help measure international migration. The Bayesian framework proposed is used to combine data from the Labour Force Survey (LFS) and the Facebook Advertising Platform to study the number of European migrants in the United Kingdom, with the aim of producing more accurate estimates of the numbers of European migrants. The overarching model is divided into a Theory-Based Model of migration and a Measurement Error Model. We review the quality of the LFS and Facebook data, paying particular attention to the biases of these sources. The results indicate visible yet uncertain differences between model estimates using the Bayesian framework and individual sources. Sensitivity analysis techniques are used to evaluate the quality of the model. The advantages and limitations of this approach, which can be applied in other contexts, are discussed. We cannot necessarily trust any individual source, but combining them through modeling offers valuable insights.

AMERICA’S HISTORICAL MEDIA FASCINATION WITH RUSSIA: THE NEW YORK TIMES AND RUSSIAN JEWS 1851-1905

This article details how one newspaper The New York Times portrayed Russian Jews between 1851 and 1905 and seeks to answer how and why there were certain periods of time that reporting on Russian Jews peaked in the newspaper. The results demonstrated that during time periods of significant immigration of Russian Jews to the United States, namely 1881-1882, 1890-1893, and 1903-1905, The New York Times reported significantly more about Jewish persecution in Russia. The results also demonstrate that news stories about Russia may have appealed to American citizens, particularly when the portrayal of Russia was either sensationalized or negative. The methods used were analysis of historical The New York Times newspaper articles as well as quantification of articles used through categorizing by date of publication. For example, in the 1870s 6 articles related to Russian Jews were published in The New York Times, 80 in the 1880s, 170 in the 1890s, and 407 between 1900 and 1905. The extent of which Americans were interested in Russia is subject for later research by comparison to how other newspapers portrayed Russia during this same immigration period. This research only focuses on one source as a baseline to discover trends in reporting within an individual source.

Software evolution: the lifetime of fine-grained elements

A model regarding the lifetime of individual source code lines or tokens can estimate maintenance effort, guide preventive maintenance, and, more broadly, identify factors that can improve the efficiency of software development. We present methods and tools that allow tracking of each line’s or token’s birth and death. Through them, we analyze 3.3 billion source code element lifetime events in 89 revision control repositories. Statistical analysis shows that code lines are durable, with a median lifespan of about 2.4 years, and that young lines are more likely to be modified or deleted, following a Weibull distribution with the associated hazard rate decreasing over time. This behavior appears to be independent from specific characteristics of lines or tokens, as we could not determine factors that influence significantly their longevity across projects. The programing language, and developer tenure and experience were not found to be significantly correlated with line or token longevity, while project size and project age showed only a slight correlation.

TO THE PROBLEM OF PHRASEOLOGICAL UNITS REFLECTION IN DICTIONARIES OF DIFFERENT TYPES

Постановка задачи. Статья посвящена детальному анализу фразеологизмов английского языка различных тематических групп и особенностям их регистрации в англо-английских и англо-русском словарях и справочных пособиях. Рассматривается ряд характеристик, которые отличают фразеологические единицы от свободных словосочетаний. Кроме того, исследуется вопрос включения пословиц в состав фразеологического фонда того или иного языка. Впоследствии отобранные методом сплошной выборки фразеологические единицы классифицируются по различным основаниям, а также проводится детальный анализ особенностей их отражения в представленных изданиях. Результаты. Осуществляется классификация фразеологизмов по следующим категориям: функция в коммуникации, определяемая их структурно-семантическими особенностями, а также тематическое деление. Отдельно рассматриваются фразеологизмы-эвфемизмы, относящиеся к нескольким тематическим группам, среди которых смерть, ругательства и беременность. Выделяются и описываются характерные особенности организации микроструктуры (словарной статьи) каждого отдельно взятого издания. Выводы. На основании проведенного анализа регистрации английских фразеологизмов сделаны выводы о том, что данная лексика получает подробное и точное отражение в справочниках. Проведенный анализ теоретической литературы показал правомерность включения пословиц во фразеологический фонд, поскольку они принадлежат к культурному наследию того или иного народа и воспроизводятся в речи в исходной форме. Тип и адресат справочника определяют особенности организации словарной статьи, а также компоненты, которые входят в нее (дефиниция, переводной эквивалент, иллюстративный пример, грамматическая, стилистическая, региональная и этимологическая пометы, графическая иллюстрация). Statement of the problem. The article is devoted to a detailed analysis of the phraseological units of the English language of various thematic groups and the features of their registration in the English-English and English-Russian dictionaries and reference books. Features that distinguish phraseological units from free phrases are studied. More than that, the question of belonging proverbs to phraseological stock is studied. Then phraseological units selected by the continuous sampling method are classified according to different grounds, and a detailed analysis of the features of their reflection in the analyzed sources is carried out. Results. Phraseological units are classified into some categories according to the following criteria: function in communication, determined by their structural and semantic features and thematic division. Phraseological units-euphemisms related to several thematic groups, including death, curse words and pregnancy are studied. The characteristic features of microstructure organization of each individual source are described. Conclusion. The analysis of English phraseological units registration showed that this lexis is reflected in dictionaries in a proper way. Theoretical literature analysis shows justification of proverbs inclusion into phraseological stock as they are a part of national cultural heritage and are reproduced in speech in the basic form. Further, the author comes to a conclusion that dictionary type and addressee of the reference book determine features of microstructure organization and their components (definition, translation equivalent, illustrative example, grammar, stylistic, regional and etymological labels, graphic illustration).