scholarly journals Revealing the True Nature of Hen 2-428

Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 88 ◽  
Author(s):  
Nicole Reindl ◽  
Nicolle Finch ◽  
Veronika Schaffenroth ◽  
Martin Barstow ◽  
Sarah Casewell ◽  
...  

The nucleus of Hen 2-428 is a short orbital period (4.2 h) spectroscopic binary, whose status as potential supernovae type Ia progenitor has raised some controversy in the literature. We present preliminary results of a thorough analysis of this interesting system, which combines quantitative non-local thermodynamic (non-LTE) equilibrium spectral modelling, radial velocity analysis, multi-band light curve fitting, and state-of-the art stellar evolutionary calculations. Importantly, we find that the dynamical system mass that is derived by using all available He II lines does not exceed the Chandrasekhar mass limit. Furthermore, the individual masses of the two central stars are too small to lead to an SN Ia in case of a dynamical explosion during the merger process.

2011 ◽  
Vol 7 (S281) ◽  
pp. 221-222
Author(s):  
A. Danehkar ◽  
D. J. Frew ◽  
O. De Marco ◽  
Q. A. Parker

AbstractWe use photoionization modeling to assess the binary nature of the central stars of NGC 2392 and NGC 6026. If they are close binaries, they are potential Type Ia supernovae (SNe Ia) progenitors if the total mass exceeds the Chandrasekhar limit. We show that the nucleus of NGC 2392 likely has a hot, massive (≃1 M⊙) white dwarf companion, and a total mass of ~1.6 M⊙, making it an especially interesting system. The binary mass in NGC 6026 is less, ~1.1 M⊙. Even though its orbital period is short, it is not considered to be an SNe~Ia progenitor.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Xudong Zhu ◽  
Zhiyang Chen ◽  
Weiyan Shen ◽  
Gang Huang ◽  
John M. Sedivy ◽  
...  

AbstractRemarkable progress in ageing research has been achieved over the past decades. General perceptions and experimental evidence pinpoint that the decline of physical function often initiates by cell senescence and organ ageing. Epigenetic dynamics and immunometabolic reprogramming link to the alterations of cellular response to intrinsic and extrinsic stimuli, representing current hotspots as they not only (re-)shape the individual cell identity, but also involve in cell fate decision. This review focuses on the present findings and emerging concepts in epigenetic, inflammatory, and metabolic regulations and the consequences of the ageing process. Potential therapeutic interventions targeting cell senescence and regulatory mechanisms, using state-of-the-art techniques are also discussed.


2016 ◽  
Vol 8 (3) ◽  
pp. 5
Author(s):  
Jirí Stavek

<p class="1Body">An attempt is presented for the description of the spectral colors using the standard trigonometric tools in order to extract more information about photons. We have arranged the spectral colors on an arc of the circle with the radius R = 1 and the central angle θ = π/3 when we have defined cos (θ) = λ<sub>380</sub>/λ<sub>760</sub> = 0.5. Several trigonometric operations were applied in order to find the gravity centers for the scotopic, photopic, and mesopic visions. The concept of the center of gravity of colors introduced Isaac Newton. We have postulated properties of the long-lived photons with the new interpretation of the Hubble (Zwicky-Nernst) constant H<sub>0</sub> = 2.748… * 10<sup>-18</sup> kg kg<sup>-1 </sup>s<sup>-1</sup>, the specific mass evaporation rate (SMER) of gravitons from the source mass. The stability of international prototypes of kilogram has been regularly checked. We predict that those standard kilograms due to the evaporation of gravitons lost 8.67 μg kg<sup>-1</sup> century<sup>-1</sup>. The energy of long-lived photons was trigonometrically decomposed into three parts that could be experimentally tested: longitudinal energy, transverse energy and energy of evaporated gravitons. We tested the properties of the long-lived photons with the experimental data published for the best available standard candles: supernovae Type Ia. There was found a surprising match of those experimental data with the model of the long-lived photons. Finally, we have proposed a possible decomposition of the big G (Newtonian gravitational constant) and the small kappa κ (Einsteinian gravitational constant) in order to get a new insight into the mysterious gravitational force and/or the curvature concept.</p>


1978 ◽  
Vol 3 (3) ◽  
pp. 148-159 ◽  
Author(s):  
Howard S. Adelman

Presented are (1) a brief synthesis of several key conceptual and methodological concerns and some ethical perspectives related to identification of psycho-educational problems and (2) conclusions regarding the current state of the art. The conceptual discussion focuses on differentiating prediction from identification and screening from diagnosis; three models used in developing assessment procedures also are presented. Methodologically, the minimal requirements for satisfactory research are described and current problems are highlighted. Three ethical perspectives are discussed; cost-benefit for the individual, models-motives-goals underlying practices, and cost-benefit for the culture. The current state of the art is seen as not supporting the efficacy of the widespread use of currently available procedures for mass screening. Given this point and the methodological and ethical concerns discussed, it is suggested that policy makers reallocate limited resources away from mass identification and toward health maintenance and other approaches to prevention and early-age intervention.


2017 ◽  
Vol 18 (2) ◽  
pp. 107-117 ◽  
Author(s):  
György Kovács

Abstract The transport activity is one of the most expensive processes in the supply chain. Forwarding and transport companies focuses on the optimization of transportation and the reduction of transport costs. The goal of this study is to develop a method which calculate the first (prime) cost of a given transport task more precisely than the state of the art practices. In practice the calculation of transport fee depends on the individual estimation methods of the transport managers, which could result losses for the company. In this study the elaborated calculation method for total first cost is detailed for three types of fulfilment of transport tasks. The most common type of achievement is, when “own vehicle is used with own driver”. A software was also developed for this case based on the elaborated method. Based on the calculations of our software, the first cost can be defined quickly and precisely to realize higher profit.


Author(s):  
Trung Minh Nguyen ◽  
Thien Huu Nguyen

The previous work for event extraction has mainly focused on the predictions for event triggers and argument roles, treating entity mentions as being provided by human annotators. This is unrealistic as entity mentions are usually predicted by some existing toolkits whose errors might be propagated to the event trigger and argument role recognition. Few of the recent work has addressed this problem by jointly predicting entity mentions, event triggers and arguments. However, such work is limited to using discrete engineering features to represent contextual information for the individual tasks and their interactions. In this work, we propose a novel model to jointly perform predictions for entity mentions, event triggers and arguments based on the shared hidden representations from deep learning. The experiments demonstrate the benefits of the proposed method, leading to the state-of-the-art performance for event extraction.


2014 ◽  
Vol 17 (17) ◽  
pp. 197-220
Author(s):  
Oscar Hernán Cerquera Losada

Este documento muestra el Estado de arte de los determinantes del rendimiento académico en la educación media, teniendo en cuenta las principales investigaciones realizadas, tanto a nivel nacional como internacional, acerca de los factores que influyen en el logro escolar de los estudiantes. Con este trabajo, se busca establecer las principales variables, tanto en Colombia como en algunos lugares del mundo, que afectan el desempeño académico de los estudiantes. Este documento se organiza en dos sesiones, determinantes a nivel mundial y determinantes a nivel colombiano; cada sesión clasifica las investigaciones de acuerdo a los factores del estudiante, de la escuela y las características organizacionales y políticas. A pesar de existir muchas investigaciones sobre el tema, aún no se ha llegado a un consenso general sobre cómo determinar los factores del  rendimiento académico, pues en la realidad son muchas las características del individuo, la escuela o el sistema que se relacionan entre sí de diferente manera y pueden afectar el logro estudiantil.ABSTRACTThis document shows the state of the art of the determinants of academic achievement in secondary education, taking into account the main research conducted, both nationally and internationally, about the factors that influence school achievement of students. With this paper, we seek to establish the main variables which affect the academic achievement of students in Colombia as well as in some parts of the world. This document is organized in two sessions: world and Colombian determinants; each session classifies research according to the factors of the student, the school and organizational and political characteristics. Although there is much research on the topic so far it has not been possible to reach a consensus on how to determine the factors of academic achievement, because in reality many characteristics of the individual, of the school or of the system relate to each other differently and can affect student achievement.RESUMOEste documento mostra o Estado da arte dos determinantes do rendimento escolar no ensino medio, tendo em conta às principais pesquisas realizadas, tanto a nível nacional como internacionalmente, sobres os fatores que influenciam o desempenho escolar dos estudantes. Com este trabalho, se procura estabelecer as principais variáveis, tanto na Colômbia e em alguns lugares do mundo, afetando o desempenho acadêmico dos estudantes. Este documento está organizado em duas sessões, determinantes a nível mundial e determinantes a nível colombiano; cada sessão clasifica as pesquisas de acordó a os fatores do estudante, da escola e das características organizacionais e políticas. Embora haja muitas pesquisas sobre o tema, ainda não se chegou a um consenso geral sobre os fatores determinantes no desempenho acadêmico, porque na realidade são muitas as características do indivíduo, a escola ou o sistema que se relacionam uns com os outros de forma diferente e podem afetar o desempenho acadêmico.


Author(s):  
Salim Yasmineh

All the arguments of a wavefunction are defined at the same instant implying a notion of simultaneity. In a somewhat related matter, certain phenomena in quantum mechanics seem to have non-local causal relations. Both concepts are in contradiction with special relativity. We propose to define the wavefunction with respect to the invariant proper time of special relativity instead of standard time. Moreover, we shall adopt the original idea of Schrodinger suggesting that the wavefunction represents an ontological cloud-like object that we shall call &lsquo;individual fabric&rsquo; that has a finite density amplitude vanishing at infinity. Consequently, measurement can be assimilated to a confining potential that triggers an inherent non-local mechanism within the individual fabric. It is formalised by multiplying the wavefunction with a localising gaussian as in the GRW theory but in a deterministic manner.


2019 ◽  
Vol 13 (2) ◽  
pp. 29-44
Author(s):  
Péter Telek ◽  
Ákos Cservenák

Nowadays, there are many well proved, effective processes to solve planning tasks in the field of material handling used advanced calculations forms and software. Unfortunately, most of them are used for individual tasks, so the applicability of their results is limited. The Institute of Logistics of the University of Miskolc has been working on integrated planning of handling machines for decades, where the individual planning tasks have to be solved together in a complex process. The main aim of this paper to give an overview about the state of the art of the planning of material handling, based on a literature review of the Science Direct publication database. As a result of this research we can determine some new direction for the planning of material handling.


2020 ◽  
Vol 110 (04) ◽  
pp. 220-225
Author(s):  
Matthias Schmidt ◽  
Janine Tatjana Maier ◽  
Mark Grothkopp

Produzierende Unternehmen stehen in einem dynamischen Umfeld vor der Herausforderung eine zunehmende Datenmenge effizienter zu verarbeiten. In diesem Zusammenhang werden häufig Ansätze des maschinellen Lernens (ML) diskutiert. Der Beitrag stellt eine umfassende Aufarbeitung des Stands der Forschung bezogen auf den Einsatz von ML-Ansätzen in der Produktionsplanung und -steuerung (PPS) bereit. Daraus lässt sich der Forschungsbedarf in den einzelnen Aufgabengebieten der PPS ableiten. &nbsp; In a dynamic environment, manufacturing companies face the challenge of processing an increasing amount of data more efficiently. In this context, approaches of machine learning (ML) are often discussed. This paper provides a comprehensive review of the state of the art regarding the use of ML approaches in production planning and control (PPC). Based on this, the need for research in the individual task areas of PPC can be derived.


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