bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of reliability of power supply of ship's responsible power receivers
Authors: Кузнецов С.Е. , Алексеев Н.А. , Виноградов А.А. 
Published: December 2020

Изложена методика расчета показателей безотказности электроснабжения (вероятности безотказного электроснабжения и средней наработки до отказа) ответственных приемников морского судна, подключаемых к аварийному электрораспределительному щиту. Методика реализована применительно к судовой электроэнергетической системе с тремя источниками электроэнергии – двумя основными дизель-генераторными агрегатами, подключенными к главному электрораспределительному щиту, и одним аварийным дизель-генераторным агрегатом, подключенным к аварийному электрораспределительному щиту. Рассмотрены различные режимы работы судовой электроэнергетической системы: при работе до первого отказа одного основного дизель-генератора, при параллельной работе двух основных дизель-генераторов, при работе одного аварийного дизель-генератора; а также после обесточивания с учетом возможности последующего включения резервного или (и) аварийного дизель генератора. Методика, с соответствующими корректировками, может быть использована для расчета показателей безотказного электроснабжения в судовых электроэнергетических системах другой комплектации. Расчет показателей безотказности электроснабжения необходим при проектировании для обеспечения требуемого уровня надежности электроснабжения судовых приемников электроэнергии, а при эксплуатации – для предупреждения отказов и планирования технического обслуживания и ремонта элементов судовых электроэнергетических систем.
The methodology for calculating the indicators of the reliability of power supply (the probability of failure-free power supply and the mean time to failure) of critical receivers of a sea vessel connected to the emergency electrical switchboard is presented. The technique is implemented in relation to a ship power system with three sources of electricity - two main diesel generator sets connected to the main electrical switchboard, and one emergency diesel generator set connected to an emergency electrical switchboard. Various operating modes of the ship's electric power system are considered: during operation until the first failure of one main diesel generator, during parallel operation of two main diesel generators, during operation of one emergency diesel generator; as well as after de-energizing, taking into account the possibility of subsequent switching on of the backup and / or emergency diesel generator. The technique, with appropriate adjustments, can be used to calculate indicators of reliable power supply in ship power systems of a different configuration. Calculation of power supply reliability indicators is necessary during design to ensure the required level of power supply reliability for ship power receivers, and during operation - to prevent failures and plan maintenance and repair of elements of ship power systems.
Electric consumption predictions objects of socio-economic systems based on the ranked values
Authors: Гнатюк В.И. , Кивчун О.Р. , Морозов Д.Г. 
Published: December 2020

Авторами предлагается алгоритм прогнозирования электропотребления объектов социально-экономических систем на основе значений ранговых норм. В его основу положено понятие ранговой нормы, представляющей собой неотрицательный функционал, заданный в векторном ранговом пространстве и обобщающий понятие длины вектора или абсолютного значения параметра. Основными этапами алгоритма являются: импорт данных по электропотреблению, расчёт ранговых норм, прогнозирование значений ранговых норм и исходных значений электропотребления, восстановление прогнозных значений ранговых норм, сравнение результатов прогнозирования и выбор наилучшего прогноза. Эксперементальная проверка алгоритма была реализована на данных по электропотреблению регионов Российской Федерации. Анализ результатов прогнозов позволил определить, что средние относительные и абсолютные ошибки метода прогнозирования на основе значений ранговых норм, меньше. Данный факт позволяет сделать вывод о том, что для среднесрочного прогнозирования целесообразнее использовать метод на основе значений ранговых норм.
The authors propose an algorithm for predicting the power consumption of objects of socio-economic systems based on the values of rank norms. It is based on the concept of a rank norm, which is a non-negative functional specified in a vector rank space and generalizing the concept of the length of a vector or the absolute value of a parameter. The main stages of the algorithm are: importing data on power consumption, calculating rank norms, predicting the values of rank norms and initial values of power consumption, restoring the predicted values of rank norms, comparing forecast results and choosing the best forecast. Experimental verification of the algorithm was carried out on data on power consumption of the regions of the Russian Federation. Analysis of the forecast results allowed us to determine that the average relative and absolute errors of the forecasting method based on the values of rank norms are less. This fact allows us to conclude that it is more expedient to use the method based on the values of rank norms for medium-term forecasting.
Optimization and Feasibility of Alizarin Red S Retention on Iron- Loaded Cellulose Nanocomposite Bead
Authors: Mitali Sarkar  , Pankaj Sarkar  , Swagatam Sarkar  , Shanku Denrah  
Published: December 2020

Iron(III) loaded cellulose nanocomposite bead, synthesized through sol-gel method, was characterized by Fourier transform infra-red spectroscopy, field emission scanning electron microscopy, energy dispersive spectroscopy, atomic force microscopy, tunneling electron microscopy, and tested for adsorptive removal of alizarin red S from aqueous solution. The influence of variables such as pH, contact time, initial dye concentration, adsorbent dose and temperature for dye retention were investigated in batch operation. The process was optimized by employing response surface methodology following full factorial and central composite design. The maximum adsorption of 97% was observed at an optimum condition of pH 3.0, dose of 2.0 gdm-3 and shaking time of 45 mins corresponding to the dye concentration of 100 mgdm-3 at 303 K. Correlation of cooperative influences of the significant variables and the extent of dye adsorption were represented by a second order polynomial equation. The mutual interactions of the significant variables were presented by 3D response surface and 2D contour plots in the design space. The adsorption was better described by Langmuir isotherm and pseudo second order kinetics. The process was spontaneous (-∆G°, 48.19 kJmol-1 ), feasible (∆S°, 0.284 Jmol -1 K-1 ) and endothermic (∆H°, 71.62 kJmol-1 ). The adsorbent can be regenerated with NaOH (10.0 × 10-2 M) and recycled for reuse, at least for five successive operations.
CHARACTERISTICS OF THE BODY STATE IN THE ASSESSMENT OF HUMAN PERFORMANCE
Authors: Невзоров Валерий Петрович , Буланова Татьяна Михайловна , Пырву Вячеслав Владимирович 
Published: December 2020

Изменения функциональной активности в организме человека проявляются в виде согласованных и стабильных физиологических колебательных процессов. Эти изменения выражаются конкретной характеристикой, отражающейся в виде показателей фазовых колебаний, которые нами использованы для оценки работоспособности человека.
Changes of functional activity in a human body manifest itself in the form of the coordinated and stable physiological oscillatory processes. These changes are expressed as a particular characteristic in the form of indicators of phase fluctuations, which we use to assess human performance.
A Variable Ionized Disk Wind in the Black Hole Candidate EXO 1846–031
Authors: Wang Yanan , Ji Long , García Javier A. , Dauser Thomas , Méndez Mariano , Mao Junjie , Tao L. , Altamirano Diego , Maggi Pierre , Zhang S. N. , Ge M. Y. , Zhang L. , Qu J. L. , Zhang S. , Ma X. , Lu F. J. , Li T. P. , Huang Y. , Zheng S. J. , Chang Z. , Tuo Y. L. , Song L. M. , Xu Y. P. , Chen Y. , Liu C. Z. , Bu Q. C. , Cai C. , Cao X. L. , Chen L. , Chen T. X. , Chen Y. P. , Cui W. W. , Du Y. Y. , Gao G. H. , Gu Y. D. , Guan J. , Guo C. C. , Han D. W. , Huo J. , Jia S. M. , Jiang W. C. , Jin J. , Kong L. D. , Li B. , Li C. K. , Li G. , Li W. , Li X. , Li X. B. , Li X. F. , Li Z. W. , Liang X. H. , Liao J. Y. , Liu H. W. , Liu X. J. , Lu X. F. , Luo Q. , Luo T. , Meng B. , Nang Y. , Nie J. Y. , Ou G. , Sai N. , Shang R. C. , Song X. Y. , Sun L. , Tan Y. , Wang W. S. , Wang Y. D. , Wang Y. S. , Wen X. Y. , Wu B. B. , Wu B. Y. , Wu M. , Xiao G. C. , Xiao S. , Xiong S. L. , Yang S. , Yang Y. J. , Yi Q. B. , Yin Q. Q. , You Y. , Zhang F. , Zhang H. M. , Zhang J. , Zhang W. C. , Zhang W. , Zhang Y. F. , Zhao H. S. , Zhao X. F. , Zhou D. K. 
Published: December 2020

Abstract
After 34 yr, the black hole candidate EXO 1846–031 went into outburst again in 2019. We investigate its spectral properties in the hard intermediate and the soft states with NuSTAR and Insight-HXMT. A reflection component has been detected in the two spectral states but possibly originating from different illumination spectra: in the intermediate state, the illuminating source is attributed to a hard coronal component, which has been commonly observed in other X-ray binaries, whereas in the soft state, the reflection is probably produced by disk self-irradiation. Both cases support EXO 1846–031 as a low-inclination system of

. An absorption line is clearly detected at ∼7.2 keV in the hard intermediate state, corresponding to a highly ionized disk wind (

) with a velocity of up to 0.06c. Meanwhile, quasi-simultaneous radio emissions have been detected before and after the X-rays, implying the coexistence of disk winds and jets in this system. If only the high-flux segment of the NuSTAR observation is considered, the observed wind appears to be magnetically driven. The absorption line disappeared in the soft state and a narrow emission line appeared at ∼6.7 keV on top of the reflection component, which may be evidence for disk winds, but data with higher spectral resolution are required to examine this.
Lorentz Invariance Violation Limits from the Spectral-lag Transition of GRB 190114C
Authors: Du Shen-Shi , Lan Lin , Wei Jun-Jie , Zhou Zi-Min , Gao He , Jiang Lu-Yao , Zhang Bin-Bin , Liu Zi-Ke , Wu Xue-Feng , Liang En-Wei , Zhu Zong-Hong 
Published: December 2020

Abstract
The spectral lags of gamma-ray bursts (GRBs) have been viewed as the most promising probes of the possible violations of Lorentz invariance (LIV). However, these constraints usually depend on the assumption of the unknown intrinsic time lag in different energy bands and the use of a single highest-energy photon. A new approach to test the LIV effects has been proposed by directly fitting the spectral-lag behavior of a GRB with a well-defined transition from positive lags to negative lags. This method simultaneously provides a reasonable formulation of the intrinsic time lag and robust lower limits on the quantum-gravity energy scales (E
QG). In this work, we perform a global fitting to the spectral-lag data of GRB 190114C by considering the possible LIV effects based on a Bayesian approach. We then derive limits on E
QG and the coefficients of the standard model extension. The Bayes factor output in our analysis shows very strong evidence for the spectral-lag transition in GRB 190114C. Our constraints on a variety of isotropic and anisotropic coefficients for LIV are somewhat weaker than existing bounds, but they can be viewed as comparatively robust and have the promise to complement existing LIV constraints. The observations of GRBs with higher-energy emissions and higher temporal resolutions will contribute to a better formulation of the intrinsic time lag and more rigorous LIV constraints in the dispersive photon sector.
The Pulsating White Dwarf G117-B15A: Still the Most Stable Optical Clock Known
Authors: Kepler S. O. , Winget D. E. , Vanderbosch Zachary P. , Castanheira Barbara Garcia , Hermes J. J. , Bell Keaton J. , Mullally Fergal , Romero Alejandra D. , Montgomery M. H. , DeGennaro Steven , Winget Karen I. , Chandler Dean , Jeffery Elizabeth J. , Fritzen Jamile K. , Williams Kurtis A. , Chote Paul , Zola Staszek 
Published: December 2020

Abstract
The pulsating hydrogen atmosphere white dwarf star G 117-B15A has been observed since 1974. Its main pulsation period at 215.19738823(63) s, observed in optical light curves, varies by only (5.12 ± 0.82) × 10−15 s s−1 and shows no glitches, as pulsars do. The observed rate of period change corresponds to a change of the pulsation period by 1 s in 6.2 million yr. We demonstrate that this exceptional optical clock can continue to put stringent limits on fundamental physics, such as constraints on interaction from hypothetical dark matter particles, as well as to search for the presence of external substellar companions.
Multiwavelength Analysis and the Difference in the Behavior of the Spectral Features during the 2010 and 2014 Flaring Periods of the Blazar 3C 454.3
Authors: Amaya-Almazán Raúl A. , Chavushyan Vahram , Patiño-Álvarez Victor M. 
Published: December 2020

Abstract
Over the years, the flat-spectrum radio quasar 3C 454.3 has presented phases of very high activity (flares) in which the different wave bands increase their flux dramatically. In this work, we perform multiwavelength analysis from radio to gamma-rays and study the Mg ii λ2798 emission line and the UV Fe ii band from 2008 to 2018. We found that an increase in the 43 GHz flux density of the quasi-stationary component C coincides with the estimated time at which a superluminal blob ejected from the radio core (which caused the brightest flare of 2010) collides with the quasi-stationary component (at a projected distance of ∼4.6 pc from the radio core). The different behavior of the spectral index in the first (5000 < JD − 2,450,000 < 5600) and second (6600 < JD − 2,450,000 < 7900) flaring periods suggests changes in the physical conditions. The complex nature of the second period can be a result of a superposition of multiple events at different locations. The Mg ii line has an anticorrelation with the UV continuum while Fe ii correlates positively, except at the time of the brightest flare of 2010, when both have a strong response at high continuum luminosities. Our results suggest that the dominant gamma-ray emission mechanism for the first flaring period is external Compton. For the second flaring period the region emitting seed photons is co-spatial with that emitting gamma-rays. However, a study of the spectral energy distribution using a multizone jet emission model is required to confirm the nature of each significant flare during the second period.
Energy Distribution of Small-scale Flares Derived Using a Genetic Algorithm
Authors: Kawai Toshiki , Imada Shinsuke 
Published: December 2020

Abstract
To understand the mechanism of coronal heating, it is crucial to derive the contribution of small-scale flares, the so-called nanoflares, to the heating up of the solar corona. To date, several studies have tried to derive the occurrence frequency distribution of flares as a function of energy to reveal the contribution of small-scale flares. However, there are no studies that derive the distribution with considering the following conditions: (1) evolution of the coronal loop plasma heated by small-scale flares, (2) loops smaller than the spatial resolution of the observed image, and (3) multiwavelength observation. To take into account these conditions, we introduce a new method to analyze small-scale flares statistically based on a one-dimensional loop simulation and a machine-learning technique, that is, the genetic algorithm. First, we obtain six channels of Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) light curves of the active-region coronal loops. Second, we carry out many coronal loop simulations and obtain the SDO/AIA light curves for each simulation in a pseudo-manner. Third, using the genetic algorithm, we estimate the best combination of simulated light curves that reproduce the observation. Consequently, the observed coronal loops are heated by small-scale flares with energy flux larger than that typically required to heat up an active region intermittently. Moreover, we derive the occurrence frequency distribution which has various power-law indices in the range from 1–3, which partially supports the nanoflare heating model. In contrast, we find that 90% of the coronal heating is done by flares that have energy larger than 1025 erg.
A Pre-explosion Extended Effervescent Zone around Core-collapse Supernova Progenitors
Authors: Soker Noam 
Published: December 2020

Abstract
I propose a scenario according to which the dense compact circumstellar matter (CSM) that the ejecta of many core-collapse supernovae (CCSNe) collide with within several days after explosion results from a dense zone where in addition to the stellar wind there is gas that does not reach the escape velocity. In this effervescent zone around red supergiant (RSG) stars, there are dense clumps that are ejected from the vicinity of the RSG surface, rise to radii of tens of astronomical units, and then fall back. I consider two simple velocity distributions of the ejected clumps. I find that the density of the bound mass can be tens of times that of the escaping wind, and therefore can mimic a very high mass-loss rate. The dense effervescent compact CSM zone can (1) explain the collision of the ejecta of many CCSNe with a dense compact CSM days after explosion, (2) facilitate very high mass-loss rate if the star experiences powerful pre-explosion activity, (3) form dust that obscures the progenitor in the visible band, and (4) lead to an efficient mass transfer to a stellar companion at separations of tens of astronomical units, if it exists. The effervescent zone might exist for thousands of years and more, and therefore the effervescent CSM model removes the requirement from many type II CCSN progenitors to experience a very strong outburst just years to months before explosion.
A validated audio-visual educational module on examination skills in ophthalmology for undergraduate medical students in the COVID-19 season - An observational longitudinal study
Authors: Rose Jeyanth S , Lalgudi Sharmili , Joshua R Aarwin , Paul Joshua , Susanne M Aishwarya , Phillips Ashna C , Jeyaraj Chriset , Abraham Greeni , Joshua R , Vinay Samuel , Paul Padma , Amritanand Anika , Nadaraj Ambily 
Published: December 2020

Purpose:
The aim of this study was to assess the impact of an audio visual (AV) teaching module on basic torchlight examination of the eye and direct ophthalmoscopy for undergraduate medical students.

Methods:
This observational longitudinal study was done on 33 consecutive medical interns during their Ophthalmology posting from December 2019 to March 2020 at a medical college in South-India. An AV-module was created using animation graphics, narratives, demonstrations on normal individuals and on patients with positive signs. All interns had a pretest consisting of Multiple-choice questions, (MCQs) and an Objective Structured Clinical Examination (OSCE) on torchlight examination and direct ophthalmoscopy (DO). They were then shown the 20-minute AV-module. A posttest was performed immediately and after one week.

Results:
The mean pretest MCQ score was 5.84 ± 1.98. It improved to 8.81 ± 1.15 in the immediate posttest and 8.87 ± 1.66 in the one-week posttest. The mean pretest OSCE score was 12.21 ± 3.39. It improved to 23.21 ± 3.39 in the immediate posttest and 23.90 ± 3.7 in the one-week posttest. Using Generalized Estimating Equation, MCQ score improved by 2.97 units and 3.03 units and the OSCE score improved by 11 units and 11.69 units in the immediate posttest and one-week posttest respectively when compared to the pretest corresponding to the MCQ score and OSCE score (p < 0.001).

Conclusion:
AV teaching modules-for torchlight examination and DO has a significant benefit in improving knowledge and skill in undergraduate medical students. These significant results have the great translatory capacity in the current COVID-19 pandemic, where physical demonstrations involving close proximity and groups of students are highly risk prone.
PREDICTING COST CONTINGENCY FOR PRIVATE PROJECTS: CASE STUDY IN VIETNAM
Authors: TUAN KIET NGUYEN , KIM SOO-YONG , TRUONG LUU VAN , VAN HUNG LE , HUU DAT LE 
Published: December 2020

Actual cost in construction projects has tended to exceed the project budgets. Thus, cost contingency from the initial of the project is the significant budget to complete project activities. Cost contingency is an important element of cost estimation to protect project stakeholders such as owners, contractors, and architects from the risks of the project. This paper reviewed the previous studies to find the factors affecting cost contingency and proposed a regression model to predict the cost contingency for private projects in Vietnam. Through industry survey, project performance information from a total of 48 private projects in Vietnam was gathered. The research also compared with other studies to have an overview about cost contingency predicting methods. The key benefit of this research is that the project managers can use this model as another forecasting method to get a better quality cost management. The further research can be focused on developing the model for other project types in Vietnam.
COMPARISION AND STUDY OF NUMERICAL METHODS FOR DYNAMIC RESPONSE EVALUATION OF SDOF
Authors: PHUONG TRUC THAI 
Published: December 2020

Written for senior-year undergraduates and first-year graduate students with solid backgrounds in differential and integral calculus, this paper is oriented toward engineers and applied mathematicians. Consequently, this paper should be useful to senior-year undergraduates the finite element method [1]. The scaled direct approach is adopted for this purpose and each step in the finite element solution process is given in full detail. For this reason, all students must be exposed to (and indeed should master). This paper provides the general framework for the development of nearly all (nonstructural) finite element models. The finite element method of analysis is a very powerful, modern computational tool. Applications range from deformation and stress analysis of automotive, aircraft, building, and bridge structures to field analysis of beat flux, fluid flow, magnetic flux, seepage, and other flow problems. This paper presents study and comparison of numerical methods which are used for evaluation of dynamic response. A Single Degree of Freedom (SDF)-linear problem is solved by means of Newmark’s Average acceleration method [2], Linear acceleration method [2], Central Difference method [6,7] with the help of MATLAB. The advantages, disadvantages, relative precision and applicability of these numerical methods are discussed throughout the analysis.