bluuebunny/crossref_metadata_2025_split huggingface dataset:
An AC quantum voltmeter for frequencies up to 100 kHz using sub-sampling
Authors: Behr Ralf , Palafox Luis 
Published: February 2021

Abstract
Differential sampling relative to a Josephson waveform, the ac quantum voltmeter (ac-QVM), has been established as the most accurate method for measuring signals below 1 kHz with an uncertainty of 1 part in 108 (k = 1) for 1 V at 250 Hz. Commercial ac-QVMs provide accuracies of about 1 part in 106 up to frequencies of 2 kHz. Here we present a new sub-sampling technique to extend the frequency range of an ac-QVM up to 100 kHz. The measurement results at 1 V RMS amplitude agree well within 5 µV V−1 (k = 1) with the nominal voltage values for all frequencies from 500 Hz to 100 kHz. Two different analogue-to-digital converters are compared, sampling techniques, error sources and corrections as well as detailed uncertainty estimations are discussed.
Prospecting of the collision electron spectroscopy method and its integration into personal microplasma photoionization sensor CES
Authors: Tsyganov A B , Arslanova F G , Kamenev E N , Odintsov E E 
Published: February 2021

Abstract
The method of Collision Electron Spectroscopy (CES), which allowed the plasma research group of St. Petersburg Mining University to develop an innovative photoionization sensor, has several applied advantages over existing analog molecular detection methods currently used at enterprises. Though, the rate of global consumption of products manufactured at enterprises increases, which has a high risk of threat to human life and health, most developers are not able to meet the increased level of international quality standards for measuring instruments. The CES method not only makes it possible to increase the accuracy of modern measuring equipment at times, but makes the gas analyzer device portable, increases autonomy, and also significantly reduces the device’s dimensions, which, as a result, allows the device to be used as an individual portable sensor and used for diagnostics health conditions at home.
Experimental investigation of interrupting capacity of low voltage circuit breaker
Authors: Kvashnin A , Murashov Iu , Frolov V 
Published: February 2021

Abstract
The experimental results of the circuit breaker interrupting capacity are presented in the article. The scheme of the experimental workbench and diagnostic methods are described. The study was performed using high-speed shooting methods. The high-speed shooting results and diagrams for different modes are presented. The analysis of the arc divider geometry influence on the extinguishing process for different modes and power factor is completed. A parametric study of the influence of the power factor, the interrupting current magnitude and the moment of switching on the extinction of the electric arc in the circuit breaker is also performed. The influence of the arc chute geometry on the formation of a new arc attachment point is shown in the article. The test was carried out on the basis of a specially developed prototype of a low-voltage circuit breaker (AC). The obtained results can be used when designing a low-voltage circuit breaker (AC).
Simulation of the process of extruding a bar billet into a cylindrical extrusion die with active friction
Authors: Larin S N , Korotkov V A , Isaeva A N , Pasynkov A A 
Published: February 2021

Abstract
Backward extrusion processes are widespread when producing various axisymmetric hollow products. This process is characterized by high values of specific pressures. The meaningful task to be achieved is to reduce loads during this process implementation. The use of active friction forces to reduce loads seems to be promising. The use of a floating die with a protrusion on a cylindrical surface, which will facilitate the billet material pushing, is proposed. For theoretical justification of the process, the provision is made to use the finite-element method. The procedure was simulated for different geometric relationships of the tool, the floating extrusion die path velocities and the billet position relative to the extrusion die. The provision is made to analyze the influence of deformation parameters and velocity parameters on the change in force of the studied procedure. Based on the research findings, the conclusions on the expediency of the studied method use for its practical implementation have been made.
Modeling wear process of oil scraper piston rings with pyrolytic chromium coating
Authors: Maksarov V V , Krasnyy V A , Klochkov D A 
Published: February 2021

Abstract
The modern designs of oil scraper piston rings of internal combustion engines, including box-section rings with an expander are considered. Pyrolytic carbide of chrome coating of the working edges of oil scraper piston rings are proposed as a possible alternative to galvanic chromium coating. The results of model tribotechnical samples tests, which showed the effectiveness of pyrolytic chromium carbide plating in comparison with galvanic coating with chromium, are presented. Under the same conditions the wear of samples with pyrolytic chromium plating is 3.5 … 4 times less. It is shown that pyrolytic carbide chromium coating is promising for piston oil scraper rings.
Individual parameters of dark and light radiators powered by complex waveform current
Authors: Ptitsyna E V , Kuvaldin A B , Ptitsyn D V 
Published: February 2021

Abstract
The power factor is an important indicator of the installations efficiency with light and dark infrared radiators, their individual characteristics. The efficiency of installations depends on used electrical mode. In this paper, the object and subject of research are infrared ceramic lamps for heating, flexible heating tapes for electric heating systems, light infrared radiators and their operation modes powered by complex waveform current. The purpose of the research is the individual parameters of infrared radiators when the amplitude and frequency of the supply voltage are changing and develop recommendations on the choice of effective modes. The authors have solved the following tasks: to develop a method to research the physical models of installations with infrared radiators and to develop recommendations to choose the effective load operating modes based on the results of energy parameters measurements. The authors have obtained the following values of the power factor in the normal and new modes: the ceramic lamp and light radiator–0.97, the flexible heating tape - 0.83. In addition, the authors have proved that the harmonic composition of supply voltage did not deteriorate in the new mode.
Consumed power regulation algorithm in the presence of high harmonics
Authors: Skamyin A N , Rastvorova I V 
Published: February 2021

Abstract
The study of the effect of voltage on the parameters of power consumption in the presence of high harmonics in the electric network was conducted. The research was carried out with various types of loads, voltage regulation devices and reactive power compensation on the laboratory installation. It was found that, taking into account the minimization of voltage distortions, power consumption can be regulated by varying the voltage at the transformer output depending on the location of the harmonic distortion source. Based on the studies, an algorithm for power consumption regulation in the presence of high harmonics was developed. It allows minimizing the active, reactive power and distortion power while providing standardized values of the voltage total harmonic distortion ratio.
Structure modeling of mining machinery systems for production of raw peat materials
Authors: Ivanov S L , Iakupov D R , Ivanova P V , Permiakova E K 
Published: February 2021

Abstract
This work describes systems of mining machines for peat extraction, particularly, the systems that exploit environment-friendly technologies. An algorithm for schematic structure modeling of modular mining machinery systems was introduced and analyzed. Based on the analysis, an algorithm for assessing energy consumption of an entire machinery system on the basis of its structure was described. As an example, structural schemes of four modular mining machinery systems were assessed. These structural formulae were also used for structuring mining machinery systems by the energy efficiency criterion. Effectiveness value of mining machinery system is suggested to be assessed by energy efficiency coefficient. The results of the analysis and assessed models proved the viability of mining machinery systems for open-cast peat winning that combine the modules of extraction, processing, transfer, and others organized by applying devised structural formulae and energy efficiency criterion.
Modeling of the molten glass formation zone as a viscoelastic medium
Authors: Alekseeva L B , Maksarov V V 
Published: February 2021

Abstract
The article studies mathematical models that describe the movement of a viscoelastic medium. The equations of continuity, balance of forces and physical equations describing the glass melt have been created. When studying the behavior of molten glass in the formation zone, it is considered as a viscous liquid, as a viscoelastic liquid (Maxwell’s model) and as an elastic-viscous body. A system with boundary conditions is a problem of movement of the viscoelastic medium with a lower movable boundary.
Android Application Development of Student Learning Skills in Era Society 5.0
Authors: Nugraha Ariadi , Aminur Rahman Fuad 
Published: February 2021

Abstract
The aim of this paper is to discuss the android application development of student learning skills in the era 5.0. Era of society 5.0 is an era that requires every student and people to be able to have critical and constructive thinking skills, it tries to better prepare its human resources as a filter for the challenges posed by industry 4.0 which gave birth to various innovations and industrialization. With the coming of the era of Society 5.0, it is expected to be able to resolve problems and gaps in the virtual and social world systems. To realize or prepare era society 5.0 in the field of education especially in Indonesia, children need to be able to have critical, constructive and innovative ways of thinking and an appropriate understanding of their learning abilities. Therefore, from the above explanation, the development of android application of student learning skills in the era of 5.0 is needed, this is done to support the development of students in their education, especially in the era of society 5.0.
Multimedia with Social Learning Networks (SNL): As Learning Innovation in the 4.0 Industrial Era
Authors: Ramadhan Syahrul , Atmazaki  , Sukma Elfia , Indriyani Vivi 
Published: February 2021

AbstractTechnological advances have opened the door to present instructional material in various forms such as audio, visual, printed text, images, and moving images. All types of multimedia are found in one computer, which has opened the way to present learning more effectively. In addition, there were also many networking sites specifically used in learning to facilitate online learning. However, to integrate technology in learning cannot be adopted directly, it is necessary to innovate and adapt to the curriculum and learning. Based on that, it is necessary to develop a language learning model based multimedia using Social Lerning Network (SNL). This type of research is Research & Development (R&D) with a 4-D development model (define, design, develop, and disseminate). The results showed that the learning model developed was categorized as very valid and could be tested in schools.
Simulations of microturbulence in magnetised plasmas using a delta-f gyrokinetic approach with an evolving background Maxwellian
Authors: Murugappan Moahan , Donnel Peter , Brunner Stephan , Villard Laurent 
Published: February 2021

Abstract
The gyrokinetic delta-f particle-in-cell (PIC) approach is known to be successful for simulating turbulence in the core of magnetic fusion plasmas, where fluctuations are relatively small and therefore the unperturbed particle distribution function, usually represented by a stationary Maxwellian f
0, remains a good choice of a control variate for reducing statistical sampling noise. However, towards the plasma edge, characterized by low density and temperature and strong gradients, relative deviation amplitudes typically become large, so that the essential assumption of |δf/f
0| << 1 underlying the delta-f PIC approach will not be valid, where δf is the fluctuating part of distribution. This motivates the study of the limits of the delta-f approach in a simplified system mimicking the plasma edge. To this end, simulations are run using GK-engine, which is a delta-f PIC code that solves the nonlinear gyrokinetic equation in a sheared slab geometry, using B-spline finite elements to represent the self-consistent electrostatic field. Initial radial density and ion temperature profiles exhibiting high logarithmic gradients representing plasma edge conditions are used. In order to avoid practical problems of particles exiting the simulation domain as the ion temperature profile relaxes, all profiles are mirrored at domain-centre and periodic boundary conditions are imposed. The validity of the delta-f approach is measured by statistical noise estimates, while monitoring relative deviation levels of temperature via the kinetic energy. In particular, the effect of background profile gradients on these measures is investigated. As a first step towards reducing the amplitude of the deviation δf, an adaptive Maxwellian f
0 is implemented, whose time dependent temperature profiles are obtained by locally relaxing kinetic energy accumulating in δf into f
0.
Optically active quadrupole edge modes in arrays of flat metallic nanodisks
Authors: Sadeghi Seyed M , Wing Waylin J , Gutha Rithvik R 
Published: February 2021

Abstract
Using experimental and simulation methods, we demonstrate that structures consisting of two-dimensional arrays of closely-packed flat metallic nanodisks can support optically active collective resonances associated with the dark edge modes. Our results show that such resonances appear as the refractive index of the superstrate increases, generating a relatively sharp peak with weak sensitivity to the variations of the environment. Using a consecutive multilayer deposition of Si on the top of the arrays we map the development of such a resonance via multi-step red shifting of the Rayleigh anomaly wavelength. The results show that when the Rayleigh wavelength is sufficiently close to the subradiant quadrupole edge modes of the nanodisks, a linearly polarized light can excite such modes, resulting in optically active collective resonance.
Highly-efficient wavefront bending with a single-layer perforated metasurface
Authors: Xiao Wan-yue , Huang Cheng-ping 
Published: February 2021

Abstract
Simultaneous control of transmission amplitude and phase in optical regime has been theoretically demonstrated, employing a single-layer metal film milled with rectangular grooves and holes that are orthogonal to each other. By designing the configuration and sizes of nano-apertures, a single outgoing polarization with field transmission coefficient of ∼0.8 and transmission phase shift covering the full 2π range can be achieved. Moreover, with the phase gradient along the surface of super-cells consisting of six sub-units, anomalous positive and negative refraction with a high efficiency (∼60%) was suggested. This perforated metasurface may provide an alternative and efficient platform for controlling light.
The Association between the Alcohol Biomarker Phosphatidylethanol (PEth) and Self-Reported Alcohol Consumption among Russian and Norwegian Medical Patients
Authors: Jørgenrud Benedicte , Kabashi Saranda , Nadezhdin Aleksei , Bryun Evgeny , Koshkina Evgenya , Tetenova Elena , Lerdal Anners , Norby Gudmund , Kolgashkin Alexey , Petukhov Alexei , Perekhodov Sergey , Davydova Elena , Vindenes Vigdis , Gamboa Danil , Bogstrand Stig Tore 
Published: February 2021

Abstract

Aims
Valid measures to identify harmful alcohol use are important. Alcohol Use Disorders Identification Test (AUDIT) is a validated questionnaire used to self-report harmful drinking in several cultures and settings. Phosphatidylethanol 16:0/18:1 (PEth) is a direct alcohol biomarker measuring alcohol consumption levels. The aim of this study was to investigate how PEth levels correlate with AUDIT-QF and weekly grams of alcohol consumed among patients in two urban hospitals. In addition, we wanted to investigate the predictive value of PEth in identifying harmful alcohol use as defined by AUDIT-QF and weekly grams of alcohol cutoffs.

Methods
A cross-sectional study comprising acute medically ill patients with measurable PEth levels (≥0.030 μM) admitted to two urban hospitals in Oslo, Norway (N = 931) and Moscow, Russia (N = 953) was conducted using PEth concentrations in whole blood, sociodemographic data and AUDIT-QF questionnaires.

Results
PEth levels from patients with measurable PEth were found to be positively correlated with AUDIT-QF scores, with PEth cutpoints of 0.128 μM (Oslo) and 0.270 μM (Moscow) providing optimal discrimination for harmful alcohol use defined by AUDIT-QF (the difference between cities probably reflecting different national drinking patterns in QF). When converting AUDIT-QF into weekly grams of alcohol consumed, the predictive value of PEth improved, with optimal PEth cutpoints of 0.327 (Oslo) and 0.396 (Moscow) μM discriminating between harmful and non-harmful alcohol use as defined in grams (≥350 grams/week).

Conclusions
By using PEth levels and converting AUDIT-QF into weekly grams of alcohol it was possible to get an improved rapid and sensitive determination of harmful alcohol use among hospitalized patients.
Web wars: males of the golden orb-web spider invest more in fights for mated females
Authors: da Silva Amanda Vieira , Oliveira Reisla , Peixoto Paulo Enrique Cardoso 
Published: February 2021

AbstractIn addition to resource value, the cost of finding mates may affect how much males invest in fights for females. The cost of finding females may be imposed through natural factors extrinsic to males, such as female spatial distribution and predation pressure, which can be challenging to simulate in laboratory conditions. Therefore, studies under natural conditions may be suitable for understanding how the costs of finding mating partners affect male investment in fights. We used the spider Trichonephila clavipes to evaluate the hypotheses that males in field conditions invest more in contests for access to 1) unmated and 2) more fecund females and 3) when access to females is harder. To test these hypotheses, we recorded the occurrence, duration, and escalation of induced contests between males located in webs of females that differed in reproductive status (estimated by female life stage), fecundity (estimated by female abdominal area), and spatial distribution (i.e., isolated or aggregated with webs of other females). The occurrence and duration of contests were unrelated to female value or search costs. However, the probability for escalation was higher when males were fighting for adult (and probably mated) females. We also found that males tended to start a contest more often in aggregated webs. These results indicate that males of T. clavipes adjust investment in contests but contrarily to what we expected. We suggest that males invest more in contests for adult females because they are defending females that they previously fertilized to avoid sperm competition.
HiCRep.py: fast comparison of Hi-C contact matrices in Python
Authors: Lin Dejun , Sanders Justin , Noble William Stafford 
Published: February 2021

Abstract

Motivation
Hi-C is the most widely used assay for investigating genome-wide 3D organization of chromatin. When working with Hi-C data, it is often useful to calculate the similarity between contact matrices in order to assess experimental reproducibility or to quantify relationships among Hi-C data from related samples. The HiCRep algorithm has been widely adopted for this task, but the existing R implementation suffers from run time limitations on high-resolution Hi-C data or on large single-cell Hi-C datasets.

Results
We introduce a Python implementation of HiCRep and demonstrate that it is much faster and consumes much less memory than the existing R implementation. Furthermore, we give examples of HiCRep’s ability to accurately distinguish replicates from non-replicates and to reveal cell type structure among collections of Hi-C data.

Availability and implementation
HiCRep.py and its documentation are available with a GPL license at https://github.com/Noble-Lab/hicrep. The software may be installed automatically using the pip package installer.

Supplementary information
Supplementary data are available at Bioinformatics online.
Rights-Based Social Work and the Named Social Worker for Adults with Learning Disabilities: A Policy Intervention 50 Years in the Making
Authors: James Elaine 
Published: February 2021

AbstractThere has been a renewed interest in professional and academic discourse in the reconceptualisation of social work with adults as a human rights-based approach. This is compatible with the social model of disability, which philosophically adult social workers make claims to align with. This was recently argued for when the Department of Health in England piloted a named social worker for adults with learning disabilities, whose behaviour challenged services. This paper discusses the conceptualisation of rights-based practice, its relevance and appropriateness for contemporary social work policy. Drawing on the recognition theory literature, it shall be shown that the meta-theory of rights-based practice may have relevance to contemporary social work practice with adults with learning disabilities. The paper shall also consider the renewed interest in normative reconstruction in social work practice and influencing factors such as drives towards individualism and marketisation. It will consider how these impacted on the adoption into UK policy of social work as a positive intervention to address structural inequalities, perhaps more accurately described as disablism, experienced by adults with learning disabilities, which ultimately is concluded to be a ‘wicked problem’.