bluuebunny/crossref_metadata_2025 huggingface dataset:
التوسع الحضري لمدينة المرج في الفترة 2006 - 2011 م
Authors: علي د. أسامة خيرالله
Published: February 2020

جاءت هذه الدراسة لتسليط الضوء على النمو الحضري لمدينة المرج في الفترة 2006 - 2011م حيث تم التعرض الي الزيادة السكانية في ليبيا بشكل عام ثم الزيادة السكانية في مدينة المرج
Improve the Adaptive Capacity of Applications by Means Effect of the Maximum Power Point Tracking in the Photovoltaic System
Authors: Saed Ayman R. Khaled Saed
Published: February 2020

Solar arrays are nonlinear devices, and as a result the output current-voltage are dependent on their bias point. Power can be optimized by biasing the PV cell’s voltage at the maximum power point (MPP). The PV array is affected by solar irradiation, cell temperature, age, loading condition, and other conditions. These variations are also having nonlinear responses, which needed to control with the help of buck boost converter to ensure that maximum power output is transferred to the load. This paper summarizes some of important applications of the MPPT. A comparison between direct and indirect connected to resistive load with MPPT in terms of PV total energy. The MPPT algorithm, which is based on the perturb and observe method) plays an important function that is developed in MATLAB Simulation, and the outputs are observed. It includes module BP SX 150S for a solar photovoltaic. This module approximately provides a maximum power of 150 W.
Natural Gas Seismic Safety Measures in Turkey: Experimental Work and Revised Standard
Authors: KARAKALE Prof. Dr. Vail
Published: February 2020

One of the safety measures to prevent possible post earthquake natural gas fires in Turkey is the use of gas shut-off valves in residential buildings. In this paper shake table tests on gas shut-off valves produced in Turkey were conducted to investigate the suitability of using the American standard ASCE25-06 gas actuation limits in the Turkish standard (TS12884). Furthermore as a part of the pipeline network health monitoring project for Istanbul gas distribution company IGDAS; a full scale natural gas district regulator controlled by SI intelligent sensor was tested under strong ground motions to examine its seismic performance. Results indicate that more than 50% of the valves actuate below the lower limits specified by ASCE25-06 .This may increase gas service costs even after small earthquakes. Furthermore results shows that the soil type conditions play an important role in specifying the upper limits of gas auction. At the end of tests even the regulator was tested under strong ground motions, its main system survived with no damage at all. Lastly; tests shows that the intelligent sensor is a vital device for gas safety.
تتحقق معالجة الفساد الإداري والمالي بالشركة العامة للكهرباء الليبية بتطبيق الحوكمة
Authors: هزاوي د. عطية صالح , الصويعي أ. عادل شيفر
Published: February 2020

هدفت هذه الدراسة إلى التعريف بمفهوم الفساد الإداري والمالي، وكيفية معالجته بتطبيق الحَوْكَمَةُ على المؤسسات الاقتصادية الليبية، ا ولتعرف على أهم المعوقات الإجرائية لعدم تطبيق ق ا وعد الحَوْكَمَة بها، وبيان تأثيرها السلبي على الاقتصاد في الليبي، ولقد اجريت دراسة الحالة على الشركة العامة للكهرباء في المرج وطبرق وما حولهما في ليبيا محل الدراسة؛ والتي تمثلت في جميع العاملين الإداريين والفنيين بالشركة، ولقد بلغت عدد عينة الدراسة (164) مبحوثاً، وفي هذه الدراسة تمت الاستنتاجات من تحليل البيانات الواردة من عينة الدراسة بالحاسب الآلي باستخدام البرنامج الإحصائي (SPSS) ، ومن بعض الدراسات السابقة، وبعد التأكد من مصداقيتها بواسطة المتخصصين وتأكيد معامل ثباتها إحصائياً، كشفت الدراسة التالي: أن المخرج الوحيد، والحل الفعال لمعالجة ظاهرة الفساد المالي والإداري، من أجل تحقيق الجودة العالية، وتحسين عملية صنع القرار الرشيد،
مدى اختلاف التفكيرٌ ما وراء المعرف تبعاً لاختلاف مستوى التحصيلٌ الدراس والنوع لدى عينٌة من طلبة كليةٌ التربيةٌ المرج
Authors: صالح د. حامد المبروك
Published: February 2020

هدفت هذه الدراسة إلى معرفة الفروق في التفكيرٌ ما وراء المعرف تبعاً لاختلاف مستوى التحصيلٌ الدراس والنوع، وتكونت عينٌة الدراسة من (133) طالباً وطالبة من كلبةٌ التربيةٌ المرج، ولتحقيقٌ أهداف الدراسة تم استخدام مقياٌس ما وراء المعرفة الذي عرّبه السيدٌ محمد أبو هاشم ( 1999)  أظهرت نتائج الدراسة وجود فروق ذات دلالة إحصائيةٌ في التفكيرٌ ما وراء المعرفي تعزى لمستوى التحصيلٌ الدراسي ولصالح ذوي التحصيلٌ المرتفع، كما أظهرت نتائج الدراسة عدم وجود فروق ذات دلالة إحصائيةٌ في ما وراء المعرفة تعزى للنوع (ذكور - اناث).
Physiological Changes in Hematological Parameters and Nutritional Awareness of Pregnant women in Al-bayda city.
Authors: Abufarua Salmin A. A. , , Alshailabi Eda M.A. Alshailabi , Joumaa Elham .
Published: February 2020

Pregnancy is characterized by a deep modification of physiological functions of the pregnant woman's body. Indeed, during the pregnancy, there is a considerable increase of the metabolic needs, as well as modifications of the hormonal balance. These phenomena provide enough justification for the hematological disorders. Low hemoglobin or anemia is one of the most commonly encountered medical disorders during pregnancy. The study was descriptive cross sectional study, conducted during the period from October 2017 to December 2017, aimed to assess the anemia status and nutritional awareness in pregnant women in Al-bayda city. Fifty pregnant women were enrolled in this study, from each woman, 2 mL of venous blood was collected for measuring the RBCs count, hemoglobin, hematocrit, and mean corpuscular volume the data were collected using questionnaire. The main result showed that significant decreased in RBCs count, hemoglobin, hematocrit, and mean corpuscular volume of pregnant women who have poor nutrition compared with pregnant women who have excellent and medium nutrition. The study concluded that the prevalence of pregnancy-related anemia was significantly higher in pregnancy women that have low economic status.
Why Teachers do not Teach Writing; Perspectives from the Libyan English Language Classrooms
Authors: S. Orafi Dr. Senussi M. , , Elshiltamy Saad A. A. , O. AL-Darraji Dr. Othman A.
Published: February 2020

This research study investigates Libyan secondary school teachers’ ideas and perspectives in relation to teaching writing, and shed light on the various contextual factors, which underpin teachers’ ideas and perspectives. Using semi-structured interviews as a data collection tool, the analysis of these interviews revealed that although teachers held positive attitudes towards the skill of writing and felt that students need to learn and master the writing skills, they (teachers) often ignored teaching the writing activities recommended by the curriculum. The interviews with the teachers some contextual factors such as students’ low level of English, the examination system, parents pressure, insufficient time and the number of the students had great impact on teachers’ decisions to skip the writing activities. This research studies provides useful messages for English language policy makers in Libya and elsewhere.
قياٌس مستوى الوعي البيئٌ لطلبة كليةٌ الآداب والعلوم المرج جامعة بنغازي في ضوء بعض المتغيرٌات دراسة مقارنة بينٌ قسم الموارد - والبيئٌة وعلم النبات
Authors: لشهب أ. سعد رجب حمدو لشهب , مبارك أ. عبد المنعم موسى علي
Published: February 2020

أجر تٌ هذه الدراسة على طلبة قسم (الموارد والبيئٌة، وعلم النبات) بكليةٌ الآداب والعلوم المرج جامعة بنغازي، لقياٌس مستوى الوعي البيئٌ ،ً ومدى إدراكهم ومعرفتهم البيئٌيةٌ، وتكونت العينٌة من(100) طالب وطالبة أخذت بنظام العينٌة العشوائيةٌ الطبقيةٌ، وقد أجري الاختبار على مقياٌس الوعي ( البيئٌ لبعدي المعلومات البيئٌيةٌ، والاتجاه نحو البيئٌة، وأظهرت النتائج تدني مستوى الوعي البيئٌ للذكور بمتوسط (58.4)عن الإناث بمتوسط (80.1) كما وجدت فروق في درجات إستجابة طلبة الريفٌ والحضر لمقياٌس الوعي البيئٌ لصالح طلبة الحضر بمتوسط قدره (83) عن طلبة الريفٌ الذينٌ بلغ متوسط إجاباتهم (48.9) كما وجد اختلاف في استجابات طلبة التخصص العلم والأدب لمقياٌس الوعي البيئٌ للدرجة الكليةٌ لصالح التخصص العلم (قسم النبات) بمتوسط بلغ (65) مقارنة بالتخصص الأدب (قسم الموارد والبيئٌة) بمتوسط قدره (61.8) في حينٌ كانت كل علاقات الارتباط بينٌ متغيرٌ الذكور والإناث (0.2) والارتباط بينٌ الريفٌ والحضر(0.2) وعلاقة الارتباط ببنٌ الموارد والبيئٌة، وعلم النبات (0.3)
مدى فاعلية الاتصال الشخصي في تحسين الصورة الذهنية بالمؤسسات الخدمية دراسة ميدانية
Authors: عبدالكريم د. فوزي عبدالرحيم
Published: February 2020

إن الاتصال الشخص بمختلؾ أشكاله له دور داخل المؤسسات من خلال تزويدٌ العاملينٌ بمختلف اللوائح والقرارات والأوامر والتوجيهٌات والنماذج والإرشادات والصلاحياٌت الخاصة وتحقيقٌ الفهم المتبادل ببنهم للمعلومات مما مٌكنهم من إنجاز أعمالهم بدقة وكفاءة عاليةٌ، فوجود الاتصال الشخص الفعال يزٌيدٌ من ارتباط العمال بعضهم ببعض و يوٌلد لديهٌم الإرادة والطموح مما دٌفعهم للرفع من أدائهم بصفة تلقائيةٌ نتيجٌة لما تٌركه هذا النوع من الاتصال على نفس تٌهم.
CUCI NEGERI DAN TINDAKAN BERTEOLOGI: Analisis Interpenetrasi Agama Dalam Praktek Adat Di Hukurila
Authors: Lopuhaa Agustinus O , Watloly A
Published: February 2020

The aim of this article is to explain about dynamic encaounters between Christian and cultural point of views on Cuci Negri, a Molucan local culture or adat.  An adat forms value and enriches a social identity of a local community, so do the Cuci Negri. Cuci Negri was (and still is) one tradition or ritual that shows the indigenous identity on Ambon Island, especially in some villagees of Leitimur. In Hukurila, this tradition is carried out every year on December 13th, to 16th. Since 1986, there had been interpenetration processes between the gospel and the custom, a new approach, compere to the former approach where church tend to penetrate indigenous religion or local custom. Study of the interpenetration process is expected to be a framework of contextual theology in Hukurila. The process of Cuci Negeri ritual reveals a dialectical relationship between the gospel and adat, which gives meaning to each other. This relation is not to weaken or eliminate each one, but gives a value or meaning of one another. Besides, Cuci Negeri is a way through which people of Hukurila maintain their cosmos, in order to remain sustainable for the future of their generation.
INFLUÊNCIA DAS TECNOLOGIAS NA ADOLESCÊNCIA: uma revisão integrativa
Authors: Figueiredo Iolanda Gonçalves de Alencar , Borges Xavier Aldo Luis , França Neres Emanuella Albuquerque de , Moura Lavôr Antônia Laryssa de
Published: February 2020

Objetivo: analisar a produção científica inserida no período de 2011 a 2017, sobre os efeitos positivos e negativos do uso das tecnologias no comportamento dos adolescentes e aspectos relacionados à saúde. Metodologia: Trata-se de uma revisão integrativa, com amostra de seis estudos. A coleta de dados foi realizada nas bases de dados, disponíveis no Portal de Periódicos da CAPES, no período de maio de 2017. Resultados: O uso abusivo das tecnologias causou impactos negativos na qualidade do sono dos estudantes. Dentre os pontos positivos do uso das tecnologias, destacam-se: a reabilitação de crianças com paralisia cerebral, distrofia muscular e distúrbios de aprendizagem; e melhoria da capacidade de aprendizado e concentração. A utilização excessiva da internet, bem como sua abstinência, pode resultar em depressão, prejuízos no desempenho escolar e transtornos de personalidade. O envio de mensagens de texto por meio de telefone celular, websites, chats, blogs e mídias sociais, se apresentaram como as tecnologias de informação e comunicação mais utilizadas. As principais intervenções elencadas pelos autores versavam sobre a educação em saúde. Conclusão: O estudo contribuiu para ampliação do conhecimento sobre como o uso abusivo das tecnologias pode acarretar problemas de saúde na população adolescente e, suscitar a elaboração de novas investigações, de caráter interventivo, com vistas ao uso positivo das tecnologias pelos adolescentes.
A EXPERIÊNCIA DO PARTO SOBRE O OLHAR DE MÃES ADOLESCENTES
Authors: Figueiredo Iolanda Gonçalves de Alenca , Lima Wallquíria Morais , Do Nascimento Hisla Silva , Lima Sanya Elayne Araújo
Published: February 2020

Objetivo: Descrever a percepção de mães adolescentes acerca da experiência do parto. Metodologia: estudo descritivo e exploratório, com abordagem qualitativa, realizado em Hospital de referência do centro-sul piauiense com 8(oito) mães adolescentes, na faixa etária de 15 (quinze) a 18 (dezoito) anos. Os dados foram coletados entre novembro de 2014 a janeiro de 2015 através de entrevista semiestruturada e analisados com base na teoria de Mynaio. Atendeu as recomendações éticas da Resolução nº 466 de 2012 e do Comitê de Ética em Pesquisa da Universidade Federal do Piauí com parecer n°. 808.585. Resultados: Quanto ao estado civil, 3 (três) das participantes declararam ser solteiras, 1 (uma) casada e 4 (quatro) em união estável. Referente ao nível de escolaridade, apenas 1(uma) referiu ter o ensino médio completo e 2(duas) disseram ter o ensino fundamental incompleto. Todas apontaram o parto como experiência dolorosa. Evidenciaram-se violações de direitos e violências obstétricas como o impedimento da entrada do acompanhante escolhido pela mulher; exames de toques sucessivos; episiotomia; retardamento do contato mãe-filho logo pós o parto; restrição hídrica e alimentar; posição litotômica e manobra de Kristeller. Solidão, preocupação com o bebê, desamparo, incapacidade de decidir sobre o seu corpo além da dor sumarizam sentimentos identificados no momento do parto. Considerações finais: Envolvimento de gestores, financiando serviços adequados e humanizados à gravidez, parto e puerpério com qualificação dos profissionais de saúde, valorização o uso de práticas baseadas em evidências e educação e saúde podem representar um jeito positivo de assistir à mulher assegurando seus direitos e tornando-as protagonistas desse momento.
A LITERATURA EM LIVROS DIDÁTICOS DO ENSINO MÉDIO À LUZ DO LETRAMENTO LITERÁRIO
Authors: Maia Claudia Fernanda Freitas , Santos Rosana Baptista dos
Published: February 2020

Este artigo apresenta os resultados de uma pesquisa desenvolvida no mestrado profissional em Educação pela Universidade Federal dos Vales do Jequitinhonha e Mucuri, cujo propósito foi examinar a metodologia de ensino da literatura em livros didáticos de Língua Portuguesa do ensino médio da rede particular e da pública, verificando, sobretudo, as propostas de ensino do conto, com base na Lei de Diretrizes e Bases da Educação Nacional (1996), nos Parâmetros Curriculares Nacionais do Ensino Médio (2002), nas Orientações Curriculares para o Ensino Médio (2006) e na Base Nacional Comum Curricular (2016). Para tanto, investigou-se a transposição do conto do suporte original para o livro didático, bem como as propostas de atividades de leitura e compreensão dos textos apresentadas em tais livros. A hipótese é que o conto foi apresentado de modo fragmentado nessas coleções, o que impossibilitaria a concretização do letramento literário nessa fase de ensino. Esta pesquisa é de cunho quanti-qualitativo e se desdobrou nas seguintes fases: uma pesquisa bibliográfica e uma pesquisa documental, durante a qual foi feita a coleta de dados, cujos livros didáticos analisados são os seguintes: Coleção Estudo – Língua Portuguesa (2016), de Flávia Roque, volumes I, II, III e IV do 1º, 2º e 3º anos e Português: contexto, interlocução e sentido (2013), de Maria Luiza M. Abaurre, volumes I, II e III. Tal estudo justifica-se porque o ensino do conto é relevante nas aulas de literatura no ensino médio, pois aproxima o leitor da literatura, bem como valoriza o caráter humanizador desse conteúdo curricular. Os resultados desta pesquisa demonstraram que não há uma escolarização adequada da literatura por meio dos manuais didáticos A e B. Por isso, espera-se que esse estudo possa contribuir para se repensar a literatura no ensino médio, principalmente, no que diz respeito à formação do leitor literário e ao letramento literário a partir do uso dos livros didáticos de Língua Portuguesa. 

 

 

Palavras chave: Conto. Ensino de literatura. Livros didáticos. Letramento literário.
MixWILD: A program for examining the effects of variance and slope of time-varying variables in intensive longitudinal data
Authors: Dzubur Eldin , Ponnada Aditya , Nordgren Rachel , Yang Chih-Hsiang , Intille Stephen , Dunton Genevieve , Hedeker Donald
Published: February 2020

The use of intensive sampling methods, such as ecological momentary assessment (EMA), is increasingly prominent in medical research. However, inferences from such data are often limited to the subject-specific mean of the outcome and between-subject variance (i.e., random intercept), despite the capability to examine within-subject variance (i.e., random scale) and associations between covariates and subject-specific mean (i.e., random slope). MixWILD (Mixed model analysis With Intensive Longitudinal Data) is statistical software that tests the effects of subject-level parameters (variance and slope) of time-varying variables, specifically in the context of studies using intensive sampling methods, such as ecological momentary assessment. MixWILD combines estimation of a stage 1 mixed-effects location-scale (MELS) model, including estimation of the subject-specific random effects, with a subsequent stage 2 linear or binary/ordinal logistic regression in which values sampled from each subject’s random effect distributions can be used as regressors (and then the results are aggregated across replications). Computations within MixWILD were written in FORTRAN and use maximum likelihood estimation, utilizing both the expectation-maximization (EM) algorithm and a Newton–Raphson solution. The mean and variance of each individual’s random effects used in the sampling are estimated using empirical Bayes equations. This manuscript details the underlying procedures and provides examples illustrating standalone usage and features of MixWILD and its GUI. MixWILD is generalizable to a variety of data collection strategies (i.e., EMA, sensors) as a robust and reproducible method to test predictors of variability in level 1 outcomes and the associations between subject-level parameters (variances and slopes) and level 2 outcomes.
MULTIPLE CRITERIA ASSESSMENT OF HIGH-RISE TIMBER BUILDINGS
Authors: Tupėnaitė Laura , Žilėnaitė Viktorija , Kanapeckienė Loreta , Sajjadian Seyed Masoud , Gečys Tomas , Sakalauskienė Lina , Naimavičienė Jurga
Published: February 2020

Although the majority of high-rise buildings are constructed from concrete and steel, there is a growing interest in the new generation of multi-storey timber buildings around the world and several ecologically sustainable structural systems have already been proposed. This research aims to review and compare the highest contemporary timber buildings in terms of economic and environmental efficiency. For this purpose, the Simple Additive Weighting (SAW) method is used. Five high-rise timber buildings are assessed according to the developed system of economic and environmental criteria. According to the multiple criteria assessment results, Mjøsa Tower, currently the tallest timber building in the world, located in Brumunddal, Norway, is ranked in the first place. This study also reveals that high-rise timber buildings are environmental friendly and high economic efficiency can be achieved by using lightweight modern engineered timber products, moreover, prefabrication of elements reduces duration and cost of the project.
Orbital Stability of Circumstellar Planets in Binary Systems
Authors: Quarles Billy , Li Gongjie , Kostov Veselin , Haghighipour Nader
Published: February 2020

Planets that orbit only one of the stars in stellar binary systems (i.e., circumstellar) are dynamically constrained to a limited range of orbital parameters, and understanding conditions on their stability is thus of great importance in exoplanet searches. We perform ∼700 million N-body simulations to identify how stability regions depend on properties of the binary, as well as the starting planetary inclination and mean longitude relative to the binary orbit. Moreover, we provide grid interpolation maps and lookup tables for the community to use our results. Through Monte Carlo methods, we determine that planets with a semimajor axis a

p
 ≲ 8% of the binary semimajor axis a
bin will likely be stable, given the known distribution of binary star parameters. This estimate varies in the Lidov–Kozai regime or for retrograde orbits to 4% or 10% of a
bin, respectively. Our method to quickly determine the circumstellar stability limit is important for interpreting observations of binaries using direct imaging with the James Webb Space Telescope, photometry with the Transiting Exoplanet Survey Satellite, or even astrometry with Gaia.
An Updated Small Magellanic Cloud and Magellanic Bridge Catalog of Star Clusters, Associations, and Related Objects
Authors: Bica Eduardo , Westera Pieter , Kerber Leandro de O. , Dias Bruno , Maia Francisco , Santos Jr. João F. C. , Barbuy Beatriz , Oliveira Raphael A. P.
Published: February 2020

We present a catalog of star clusters, associations, and related extended objects in the Small Magellanic Cloud (SMC) and the Magellanic Bridge with 2741 entries, a factor 2 more than a previous version from a decade ago. Literature data up until 2018 December are included. The identification of star clusters was carried out with digital atlases in various bands currently available in the Digitized Sky Survey and the Machine Automatique à Mésurer pour l’Astronomie. imaging surveys. In particular, we cross-identified recent cluster samples from the Visible and Infrared Survey Telescope for Astronomy near-infrared YJK

s
survey of the Magellanic System, Optical Gravitational Lensing Experiment IV, and Survey of the MAgellanic Stellar History surveys, confirming new clusters and pointing out equivalencies. A major contribution of the present catalog consists of the accurate central positions for clusters and small associations, including a new sample of 45 clusters or candidates in the SMC and 19 in the Magellanic Bridge, as well as a compilation of the most reliable age and metallicity values from the literature. A general catalog must also deal with the recent discoveries of 27 faint and ultra-faint star clusters and galaxies projected on the far surroundings of the Clouds, most of them from the Dark Energy Survey. The information on these objects has been complemented with photometric, spectroscopic, and kinematical follow-up data from the literature. The underluminous galaxies around the Magellanic System, still very few as compared to the predictions from Λ Cold Dark Matter simulations, can bring constraints to galaxy formation and hierarchical evolution. Furthermore, we provide diagnostics, when possible, of the nature of the ultra-faint clusters, searching for borders of the Magellanic System extensions into the Milky Way gravitational potential.
LEGUS and Hα-LEGUS Observations of Star Clusters in NGC 4449: Improved Ages and the Fraction of Light in Clusters as a Function of Age
Authors: Whitmore Bradley C. , Chandar Rupali , Lee Janice , Ubeda Leonardo , Adamo Angela , Aloisi Alessandra , Calzetti Daniela , Cignoni Michele , Cook David , Dale Daniel , Elmegreen B. G. , Gouliermis Dimitrios , Grebel Eva K. , Grasha Kathryn , Johnson Kelsey E. , Kim Hwihyun , Sacchi Elena , Smith Linda J. , Tosi Monica , Wofford Aida
Published: February 2020

We present a new catalog and results for the cluster system of the starburst galaxy NGC 4449, based on multiband imaging observations taken as part of the LEGUS and H
α
-LEGUS surveys. We improve the spectral energy fitting method used to estimate cluster ages, and find that the results, particularly for older clusters, are in better agreement with those from spectroscopy. The inclusion of H
α
measurements, the role of stochasticity for low-mass clusters, the assumptions about reddening, and the choices of SSP model and metallicity all have important impacts on the age dating of clusters. A comparison with ages derived from stellar color–magnitude diagrams for partially resolved clusters shows reasonable agreement, but large scatter in some cases. The fraction of light found in clusters relative to the total light (i.e., T

L
) in the U, B, and V filters in 25 different ≈ kiloparsec-size regions throughout NGC 4449 correlates with both the specific region luminosity, R

L
, and the dominant age of the underlying stellar population in each region. The observed cluster age distribution is found to decline over time as dN/dτ ∝ τ

γ
, with γ = −0.85 ± 0.15, independent of cluster mass, and is consistent with strong, early cluster disruption. The mass functions of the clusters can be described by a power law with dN/dM ∝ M

β
and β = −1.86 ± 0.2, independent of cluster age. The mass and age distributions are quite resilient to differences in age-dating methods. There is tentative evidence for a factor of 2–3 enhancement in both the star and cluster formation rate ≈100–300 Myr ago, indicating that cluster formation tracks star formation generally. The enhancement is probably associated with an earlier interaction event.
What Would Happen if We Were About 1 pc Away from a Supermassive Black Hole?
Authors: Iorio Lorenzo
Published: February 2020

We consider a hypothetical planet with the same mass m, radius R, angular momentum S, oblateness J
2, semimajor axis a, eccentricity e, inclination I, and obliquity ε of the Earth orbiting a main-sequence star with the same mass

and radius

of the Sun at a distance

from a supermassive black hole in the center of the hosting galaxy with the same mass

of, say, M87*. We preliminarily investigate some dynamical consequences of its presence in the neighborhood of such a stellar system on the planet’s possibility of sustaining complex life over time. In particular, we obtain general analytic expressions for the long-term rates of change, doubly averaged over both the planetary and the galactocentric orbital periods

and

, of e, I, ε, which are the main quantities directly linked to stellar insolation. We find that, for certain orbital configurations, the planet’s perihelion distance

may greatly shrink and even lead to, in some cases, an impact with the star. I may also notably change, with variations even of the order of tens of degrees. On the other hand, ε does not seem to be particularly affected, being shifted, at most, by

over 1 Myr. Our results strongly depend on the eccentricity

of the galactocentric motion.
A Hybrid Deep Learning Approach to Cosmological Constraints from Galaxy Redshift Surveys
Authors: Ntampaka Michelle , Eisenstein Daniel J. , Yuan Sihan , Garrison Lehman H.
Published: February 2020

We present a deep machine learning (ML)–based technique for accurately determining σ
8 and Ω
m
from mock 3D galaxy surveys. The mock surveys are built from the AbacusCosmos suite of N-body simulations, which comprises 40 cosmological volume simulations spanning a range of cosmological parameter values, and we account for uncertainties in galaxy formation scenarios through the use of generalized halo occupation distributions (HODs). We explore a trio of ML models: a 3D convolutional neural network (CNN), a power spectrum–based fully connected network, and a hybrid approach that merges the two to combine physically motivated summary statistics with flexible CNNs. We describe best practices for training a deep model on a suite of matched-phase simulations, and we test our model on a completely independent sample that uses previously unseen initial conditions, cosmological parameters, and HOD parameters. Despite the fact that the mock observations are quite small (∼0.07 h
−3 Gpc3) and the training data span a large parameter space (six cosmological and six HOD parameters), the CNN and hybrid CNN can constrain estimates of σ
8 and Ω
m
to ∼3% and ∼4%, respectively.
Modeling Dust and Starlight in Galaxies Observed by Spitzer and Herschel: The KINGFISH Sample
Authors: Aniano G. , Draine B. T. , Hunt L. K. , Sandstrom K. , Calzetti D. , Kennicutt R. C. , Dale D. A. , Galametz M. , Gordon K. D. , Leroy A. K. , Smith J.-D. T. , Roussel H. , Sauvage M. , Walter F. , Armus L. , Bolatto A. D. , Boquien M. , Crocker A. , De Looze I. , Donovan Meyer J. , Helou G. , Hinz J. , Johnson B. D. , Koda J. , Miller A. , Montiel E. , Murphy E. J. , Relaño M. , Rix H.-W. , Schinnerer E. , Skibba R. , Wolfire M. G. , Engelbracht C. W.
Published: February 2020

Interstellar dust and starlight are modeled for the galaxies of the project “Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel.” The galaxies were observed by the Infrared Array Camera and the Multiband Imaging Photometer for Spitzer on Spitzer Space Telescope, and the Photodetector Array Camera and Spectrometer and the Spectral and Photometric Imaging Receiver on Herschel Space Observatory. With data from 3.6 to 500 μm, dust models are strongly constrained. Using a physical dust model, for each pixel in each galaxy we estimate (1) dust surface density, (2) dust mass fraction in polycyclic aromatic hydrocarbons (PAHs), (3) distribution of starlight intensities heating the dust, (4) total infrared (IR) luminosity emitted by the dust, and (5) IR luminosity originating in subregions with high starlight intensity. The dust models successfully reproduce the observed global and resolved spectral energy distributions. With the angular resolution of Herschel, we obtain well-resolved maps (available online) for the dust properties. As in previous studies, we find the PAH fraction

to be an increasing function of metallicity, with a threshold oxygen abundance Z/Z
⊙ ≈ 0.1, but we find the data to be fitted best with

increasing linearly with

above a threshold value of 0.15(O/H)⊙. We obtain total dust masses for each galaxy by summing the dust mass over the individual map pixels; these “resolved” dust masses are consistent with the masses inferred from a model fit to the global photometry. The global dust-to-gas ratios obtained from this study are found to correlate with galaxy metallicities. Systems with Z/Z
⊙ ≳ 0.5 have most of their refractory elements locked up in dust, whereas in systems with Z/Z
⊙ ≲ 0.3 most of these elements tend to remain in the gas phase. Within galaxies, we find that

is suppressed in regions with unusually warm dust with

. With knowledge of one long-wavelength flux density ratio (e.g., f
160/f
500), the minimum starlight intensity heating the dust (

) can be estimated to within ∼50%, despite a variation in

of more than two orders of magnitude. For the adopted dust model, dust masses can be estimated to within ∼0.2 dex accuracy using the f
160/f
500 flux ratio and the integrated dust luminosity, and to ∼0.07 dex accuracy using the 500 μm luminosity

alone. There are additional systematic errors arising from the choice of dust model, but these are hard to estimate. These calibrated prescriptions for estimating starlight heating intensity and dust mass may be useful for studies of high-redshift galaxies.
The Stark Effect, Zeeman Effect, and Transition Dipole Moments for the B2Σ+−X2Σ+ Band of Aluminum Monoxide, AlO
Authors: Bai Xilin , Steimle Timothy C.
Published: February 2020

The experimentally measured radiative lifetimes and branching ratios were combined to determine the transition dipole moments for the B
2Σ+(v = 0–3) → X
2Σ+(v = 0–6) bands of aluminum monoxide, AlO, and compared with theoretical predictions. The B
2Σ+–X
2Σ+ (0, 1) band of a molecular beam sample of AlO was recorded at high spectral resolution both field-free and in the presence of static electric and magnetic fields. The 27Al(I = 5/2) hyperfine interaction in the B
2Σ+(v = 0) state was analyzed. The observed Stark shifts were analyzed to produce permanent electric dipole moments of 1.94(8) D and 4.45(3) D for the B
2Σ+(v = 0) and X
2Σ+(v = 1) states, respectively. It is demonstrated that the observed Zeeman spectra can be simulated using an effective Hamiltonian with the associated expected g-factors for both the X
2Σ+(v = 1) and B
2Σ+(v = 0) states.
Statistical Results for Solar Energetic Electron Spectra Observed over 12 yr with STEREO/SEPT
Authors: Dresing Nina , Effenberger Frederic , Gómez-Herrero Raúl , Heber Bernd , Klassen Andreas , Kollhoff Alexander , Richardson Ian , Theesen Solveig
Published: February 2020

This work presents a statistical analysis of near-relativistic solar energetic electron event spectra near 1 au. We use measurements of the Solar Electron and Proton Telescope (SEPT) on board STEREO in the energy range of 45–425 keV and utilize the SEPT electron event list containing all electron events observed by STEREO A and STEREO B from 2007 through 2018. We select 781 events with significant signal-to-noise ratios for our analysis and fit the spectra with single or broken-power-law functions of energy. We find 437 events showing broken power laws and 344 events only showing a single power law in the energy range of SEPT. For those events with broken power laws, we find a mean break energy of about 120 keV. We analyze the dependence of the spectral index on the rise times and peak intensities of the events as well as on the presence of relativistic electrons. The results show a relation between the power law spectral index and the rise times of the events with softer spectra belonging to rather impulsive events. Long rise-time events are associated with hard spectra as well as with the presence of higher-energy (>0.7 MeV) electrons. This group of events cannot be explained by a pure flare scenario but suggests an additional acceleration mechanism, involving a prolonged acceleration and/or injection of the particles. A dependence of the spectral index on the longitudinal separation from the parent solar source region was not found. A statistical analysis of the spectral indices during impulsively rising events where the rise times are below 20 minutes is also shown.
Energetic Particle Increases Associated with Stream Interaction Regions
Authors: Cohen C. M. S. , Christian E. R. , Cummings A. C. , Davis A. J. , Desai M. I. , Giacalone J. , Hill M. E. , Joyce C. J. , Labrador A. W. , Leske R. A. , Matthaeus W. H. , McComas D. J. , McNutt R. L. , Mewaldt R. A. , Mitchell D. G. , Rankin J. S. , Roelof E. C. , Schwadron N. A. , Stone E. C. , Szalay J. R. , Wiedenbeck M. E. , Allen R. C. , Ho G. C. , Jian L. K. , Lario D. , Odstrcil D. , Bale S. D. , Badman S. T. , Pulupa M. , MacDowall R. J. , Kasper J. C. , Case A. W. , Korreck K. E. , Larson D. E. , Livi Roberto , Stevens M. L. , Whittlesey Phyllis
Published: February 2020

The Parker Solar Probe was launched on 2018 August 12 and completed its second orbit on 2019 June 19 with perihelion of 35.7 solar radii. During this time, the Energetic Particle Instrument-Hi (EPI-Hi, one of the two energetic particle instruments comprising the Integrated Science Investigation of the Sun, IS⊙IS) measured seven proton intensity increases associated with stream interaction regions (SIRs), two of which appear to be occurring in the same region corotating with the Sun. The events are relatively weak, with observed proton spectra extending to only a few MeV and lasting for a few days. The proton spectra are best characterized by power laws with indices ranging from −4.3 to −6.5, generally softer than events associated with SIRs observed at 1 au and beyond. Helium spectra were also obtained with similar indices, allowing He/H abundance ratios to be calculated for each event. We find values of 0.016–0.031, which are consistent with ratios obtained previously for corotating interaction region events with fast solar wind ≤600 km s−1. Using the observed solar wind data combined with solar wind simulations, we study the solar wind structures associated with these events and identify additional spacecraft near 1 au appropriately positioned to observe the same structures after some corotation. Examination of the energetic particle observations from these spacecraft yields two events that may correspond to the energetic particle increases seen by EPI-Hi earlier.
Magnetic Connectivity of the Ecliptic Plane within 0.5 au: Potential Field Source Surface Modeling of the First Parker Solar Probe Encounter
Authors: Badman Samuel T. , Bale Stuart D. , Martínez Oliveros Juan C. , Panasenco Olga , Velli Marco , Stansby David , Buitrago-Casas Juan C. , Réville Victor , Bonnell John W. , Case Anthony W. , Dudok de Wit Thierry , Goetz Keith , Harvey Peter R. , Kasper Justin C. , Korreck Kelly E. , Larson Davin E. , Livi Roberto , MacDowall Robert J. , Malaspina David M. , Pulupa Marc , Stevens Michael L. , Whittlesey Phyllis L.
Published: February 2020

We compare magnetic field measurements taken by the FIELDS instrument on board Parker Solar Probe (PSP) during its first solar encounter to predictions obtained by potential field source surface (PFSS) modeling. Ballistic propagation is used to connect the spacecraft to the source surface. Despite the simplicity of the model, our results show striking agreement with PSP’s first observations of the heliospheric magnetic field from ∼0.5 au (107.5 R
⊙) down to 0.16 au (35.7 R
⊙). Further, we show the robustness of the agreement is improved both by allowing the photospheric input to the model to vary in time, and by advecting the field from PSP down to the PFSS model domain using in situ PSP/Solar Wind Electrons Alphas and Protons measurements of the solar wind speed instead of assuming it to be constant with longitude and latitude. We also explore the source surface height parameter (R
SS) to the PFSS model, finding that an extraordinarily low source surface height (1.3–1.5 R
⊙) predicts observed small-scale polarity inversions, which are otherwise washed out with regular modeling parameters. Finally, we extract field line traces from these models. By overlaying these on extreme ultraviolet images we observe magnetic connectivity to various equatorial and mid-latitude coronal holes, indicating plausible magnetic footpoints and offering context for future discussions of sources of the solar wind measured by PSP.
The Near-Sun Dust Environment: Initial Observations from Parker Solar Probe
Authors: Szalay J. R. , Pokorný P. , Bale S. D. , Christian E. R. , Goetz K. , Goodrich K. , Hill M. E. , Kuchner M. , Larsen R. , Malaspina D. , McComas D. J. , Mitchell D. , Page B. , Schwadron N.
Published: February 2020

The Parker Solar Probe (PSP) spacecraft has flown into the densest, previously unexplored, innermost region of our solar system’s zodiacal cloud. While PSP does not have a dedicated dust detector, multiple instruments on the spacecraft are sensitive to the effects of meteoroid bombardment. Here, we discuss measurements taken during PSP’s second orbit and compare them to models of the zodiacal cloud’s dust distribution. Comparing the radial impact rate trends and the timing and location of a dust impact to an energetic particle detector, we find the impactor population to be consistent with dust grains on hyperbolic orbits escaping the solar system. Assuming PSP’s impact environment is dominated by hyperbolic impactors, the total quantity of dust ejected from our solar system is estimated to be 0.5−10 tons/s. We expect PSP will encounter an increasingly intense impactor environment as its perihelion distance and semimajor axis are decreased.
Morphological Reconstruction of a Small Transient Observed by Parker Solar Probe on 2018 November 5
Authors: Wood Brian E. , Hess Phillip , Howard Russell A. , Stenborg Guillermo , Wang Yi-Ming
Published: February 2020

On 2018 November 5, about 24 hr before the first close perihelion passage of Parker Solar Probe (PSP), a coronal mass ejection (CME) entered the field of view of the inner detector of the Wide-field Imager for Solar PRobe (WISPR) instrument on board PSP, with the northward component of its trajectory carrying the leading edge of the CME off the top edge of the detector about four hours after its first appearance. We connect this event to a very small jetlike transient observed from 1 au by coronagraphs on both the SOlar and Heliospheric Observatory (SOHO) and the A component of the Solar TErrestrial RElations Observatory mission (STEREO-
A). This allows us to make the first three-dimensional reconstruction of a CME structure considering both observations made very close to the Sun and images from two observatories at 1 au. The CME may be small and jetlike as viewed from 1 au, but the close-in vantage point of PSP/WISPR demonstrates that it is not intrinsically jetlike but instead has a structure consistent with a flux rope morphology. Based on its appearance in the SOHO and STEREO-
A images, the event belongs in the “streamer blob” class of transients, but its kinematic behavior is very unusual, with a more impulsive acceleration than previously studied blobs.
The Enhancement of Proton Stochastic Heating in the Near-Sun Solar Wind
Authors: Martinović Mihailo M. , Klein Kristopher G. , Kasper Justin C. , Case Anthony W. , Korreck Kelly E. , Larson Davin , Livi Roberto , Stevens Michael , Whittlesey Phyllis , Chandran Benjamin D. G. , Alterman Ben L. , Huang Jia , Chen Christopher H. K. , Bale Stuart D. , Pulupa Marc , Malaspina David M. , Bonnell John W. , Harvey Peter R. , Goetz Keith , Dudok de Wit Thierry , MacDowall Robert J.
Published: February 2020

Stochastic heating (SH) is a nonlinear heating mechanism driven by the violation of magnetic moment invariance due to large-amplitude turbulent fluctuations producing diffusion of ions toward higher kinetic energies in the direction perpendicular to the magnetic field. It is frequently invoked as a mechanism responsible for the heating of ions in the solar wind. Here, we quantify for the first time the proton SH rate Q
⊥ at radial distances from the Sun as close as 0.16 au, using measurements from the first two Parker Solar Probe encounters. Our results for both the amplitude and radial trend of the heating rate, Q
⊥ ∝ r
−2.5, agree with previous results based on the Helios data set at heliocentric distances from 0.3 to 0.9 au. Also in agreement with previous results, Q
⊥ is significantly larger in the fast solar wind than in the slow solar wind. We identify the tendency in fast solar wind for cuts of the core proton velocity distribution transverse to the magnetic field to exhibit a flattop shape. The observed distribution agrees with previous theoretical predictions for fast solar wind where SH is the dominant heating mechanism.
Parker Solar Probe In Situ Observations of Magnetic Reconnection Exhausts during Encounter 1
Authors: Phan T. D. , Bale S. D. , Eastwood J. P. , Lavraud B. , Drake J. F. , Oieroset M. , Shay M. A. , Pulupa M. , Stevens M. , MacDowall R. J. , Case A. W. , Larson D. , Kasper J. , Whittlesey P. , Szabo A. , Korreck K. E. , Bonnell J. W. , de Wit T. Dudok , Goetz K. , Harvey P. R. , Horbury T. S. , Livi R. , Malaspina D. , Paulson K. , Raouafi N. E. , Velli M.
Published: February 2020

Magnetic reconnection in current sheets converts magnetic energy into particle energy. The process may play an important role in the acceleration and heating of the solar wind close to the Sun. Observations from Parker Solar Probe (PSP) provide a new opportunity to study this problem, as it measures the solar wind at unprecedented close distances to the Sun. During the first orbit, PSP encountered a large number of current sheets in the solar wind through perihelion at 35.7 solar radii. We performed a comprehensive survey of these current sheets and found evidence for 21 reconnection exhausts. These exhausts were observed in heliospheric current sheets, coronal mass ejections, and regular solar wind. However, we find that the majority of current sheets encountered around perihelion, where the magnetic field was strongest and plasma β was lowest, were Alfvénic structures associated with bursty radial jets, and these current sheets did not appear to be undergoing local reconnection. We examined conditions around current sheets to address why some current sheets reconnected while others did not. A key difference appears to be the degree of plasma velocity shear across the current sheets: the median velocity shear for the 21 reconnection exhausts was 24% of the Alfvén velocity shear, whereas the median shear across 43 Alfvénic current sheets examined was 71% of the Alfvén velocity shear. This finding could suggest that large, albeit sub-Alfvénic, velocity shears suppress reconnection. An alternative interpretation is that the Alfvénic current sheets are isolated rotational discontinuities that do not undergo local reconnection.
Observations of the 2019 April 4 Solar Energetic Particle Event at the Parker Solar Probe
Authors: Leske R. A. , Christian E. R. , Cohen C. M. S. , Cummings A. C. , Davis A. J. , Desai M. I. , Giacalone J. , Hill M. E. , Joyce C. J. , Krimigis S. M. , Labrador A. W. , Malandraki O. , Matthaeus W. H. , McComas D. J. , McNutt R. L. , Mewaldt R. A. , Mitchell D. G. , Posner A. , Rankin J. S. , Roelof E. C. , Schwadron N. A. , Stone E. C. , Szalay J. R. , Wiedenbeck M. E. , Vourlidas A. , Bale S. D. , MacDowall R. J. , Pulupa M. , Kasper J. C. , Allen R. C. , Case A. W. , Korreck K. E. , Livi R. , Stevens M. L. , Whittlesey P. , Poduval B.
Published: February 2020

A solar energetic particle event was detected by the Integrated Science Investigation of the Sun (IS⊙IS) instrument suite on Parker Solar Probe (PSP) on 2019 April 4 when the spacecraft was inside of 0.17 au and less than 1 day before its second perihelion, providing an opportunity to study solar particle acceleration and transport unprecedentedly close to the source. The event was very small, with peak 1 MeV proton intensities of ∼0.3 particles (cm2 sr s MeV)−1, and was undetectable above background levels at energies above 10 MeV or in particle detectors at 1 au. It was strongly anisotropic, with intensities flowing outward from the Sun up to 30 times greater than those flowing inward persisting throughout the event. Temporal association between particle increases and small brightness surges in the extreme-ultraviolet observed by the Solar TErrestrial RElations Observatory, which were also accompanied by type III radio emission seen by the Electromagnetic Fields Investigation on PSP, indicates that the source of this event was an active region nearly 80° east of the nominal PSP magnetic footpoint. This suggests that the field lines expanded over a wide longitudinal range between the active region in the photosphere and the corona.
Solar Wind Streams and Stream Interaction Regions Observed by the Parker Solar Probe with Corresponding Observations at 1 au
Authors: Allen R. C. , Lario D. , Odstrcil D. , Ho G. C. , Jian L. K. , Cohen C. M. S. , Badman S. T. , Jones S. I. , Arge C. N. , Mays M. L. , Mason G. M. , Bale S. D. , Bonnell J. W. , Case A. W. , Christian E. R. , de Wit T. Dudok , Goetz K. , Harvey P. R. , Henney C. J. , Hill M. E. , Kasper J. C. , Korreck K. E. , Larson D. , Livi R. , MacDowall R. J. , Malaspina D. M. , McComas D. J. , McNutt R. , Mitchell D. G. , Pulupa M. , Raouafi N. , Schwadron N. , Stevens M. L. , Whittlesey P. L. , Wiedenbeck M.
Published: February 2020

Several fast solar wind streams and stream interaction regions (SIRs) were observed by the Parker Solar Probe (PSP) during its first orbit (2018 September–2019 January). During this time, several recurring SIRs were also seen at 1 au at both L1 (Advanced Composition Explorer (ACE) and Wind) and the location of the Solar Terrestrial Relations Observatory-Ahead (STEREO-A). In this paper, we compare four fast streams observed by PSP at different radial distances during its first orbit. For three of these fast stream events, measurements from L1 (ACE and Wind) and STEREO-A indicated that the fast streams were observed by both PSP and at least one of the 1 au monitors. Our associations are supported by simulations made by the ENLIL model driven by GONG-(ADAPT-)WSA, which allows us to contextualize the inner heliospheric conditions during the first orbit of PSP. Additionally, we determine which of these fast streams are associated with an SIR and characterize the SIR properties for these events. From these comparisons, we find that the compression region associated with the fast-speed streams overtaking the preceding solar wind can form at various radial distances from the Sun in the inner heliosphere inside 0.5 au, with the suprathermal ion population (energies between 30 and 586 keV) observed as isolated enhancements suggesting localized acceleration near the SIR stream interface at ∼0.3 au, which is unlike those seen at 1 au, where the suprathermal enhancements extend throughout and behind the SIR. This suprathermal enhancement extends further into the fast stream with increasing distance from the Sun.