bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a mathematical apparatus for state estimation of an integrated safety system for an artificial traffic installation
Authors: Ginzburg Alexander , Kozminykh Sergey
Published: July 2021

The article is devoted to the development of a mathematical apparatus for the state estimation of the integrated security system (ISS) artificial traffic installation (ATI). The article analyzes the state characteristics of ISS ATI. It is noted that the estimates of the mathematical expectation show the general direction of changes in ISS average functioning. The article provides a selection of statistical analysis criteria for ISS ATI. The features of state analysis for ISS ATI are given. It is noted that checking the normal distribution should be a preliminary stage in the ISS ATI state analysis and a significant deviation from the normal distribution law can serve as a diagnostic sign of the of the system non-stationarity. Therefore, such a comparison is a sufficient tool for identifying the differences, and it should be used in the first stage of the analysis of the ISS ATI state, making possible to draw fairly reliable conclusions about the system state. The article presents the developed methodological principles of ISS ATI diagnostics. For stationarity ISS ATI analysis a methodology for diagnostic analysis, which consists in comparing the statistical current (dysfunctional) characteristics and reference implementations of the system functioning, has been developed. In conclusion, it was concluded that the use of this mathematical apparatus in the ATI security systems development makes it possible to significantly reduce the cost of their implementation and significantly increase ISS efficiency when implemented on ATI.
Method for determining the transmission of a garret window from a direct sun component
Authors: Guketlov Khazret , Tatarov Islam
Published: July 2021

Based on the experimental studies using the method of physical modeling under an artificial horizon NIISPh Moscow and the method of mathematical planning of the experiment, an analytical dependence of the light transmission coefficient on the direct component of sunlight, which characterizes the relationship between the height of the sun, geometric and lighting parameters of point skylights, was obtained.
Geoinformation support of the program “Integrated development of rural areas”
Authors: Sheina Svetlana , Fedorovskaya Albina , Chubarova Karina
Published: July 2021

This work is devoted to the rural areas’ integrated development issues. The advantages of a systematic approach for the sustainable development paradigm main policies’ goals implementation and the possibility of using geoinformation technologies as a tool for multidimensional analysis of rural areas are considered. A two-stage methodology for monitoring the rural settlements development, which makes it possible to assess the territory at the federal and local levels by a set of indicators reflecting the main aspects of socio-economic processes, is proposed. Special attention is paid to assessing the quality of the environment by three groups of factors that take into account environmental comfort, movement comfort and other indicators characterizing the comfort of living from the point of view of the territorial residents’ individual needs.
A lifecycle management system for capital construction facilities based on a digital cloud platform implementing information modeling methods and technologies
Authors: Zheleznov Maxim
Published: July 2021

The first is the introduction of information modeling technology (IMT) capital construction facilities (CCF) at all stages of the life cycle (LC), as well as information modeling of urban areas for the tasks of urban building and planning. The second is the digitalization of procedures and services in the field of construction, the formation of unified accessible data sets and information platforms that implement a unified information space for the construction industry. To implement the presented tasks, it is proposed to create a distributed life cycle control system for capital construction facilities (DCS LC CCF) and form a digital cloud platform (digital infrastructure) for the implementation of investment and construction projects based on the use of information modeling technologies, artificial intelligence and predictive analytics.
Optimization of the engineering surveys geodetic coordinate frame based on the Mercator projection use
Authors: Son Tran Thanh
Published: July 2021

The article proposes the use of a geodetic coordinate frame suitable for the reference plan geodetic networks of Vietnam used in engineering surveys. This framework minimizes distortion in horizontal spacing when going from ellipsoid to plane. In the course of the work, the parameters of the coordinate system and the height of the level surface were selected using the Universal Transverse Mercator (UTM). The equations used for the calculations are determined based on theoretical analysis and are easily applied in surveying.
In-site transportation of concrete mix: new typology of methods, potential and fields of modern mechanization means’ rational application
Authors: Osmanov Sergey
Published: July 2021

The main structural material in construction industry is concrete. The article discusses the features of modern methods and means of in-site transportation of the mixture that subsequently forms it and, in particular, its supply to the concreting blocks of monolithic structures. The requirements of Russian norms for this process implementation, as well as the world practice of using the machines, equipment and devices intended for this, are analyzed. A new typology of methods for in-site transportation of concrete mixture is proposed, based on the differences between them in the type and resource intensity of the main moving action. Generalized, systematized and brought to the applied form information about the productivity and parameters of the mechanization corresponding means working zones, as well as the mixture technological properties influence on the possibility of their use. The data obtained made it possible to clarify the rational use areas of the main types of such technology and to reveal the contradictions associated with this. In general, the research results presented in the article facilitate the identification of shortcomings and promising directions for improving the considered competing methods and technical means, as well as justification of the choice between them.
Problems of achieving energy efficiency in residential low-rise housing construction within the framework of the resource-saving technologies use
Authors: Sekisov Aleksandr
Published: July 2021

This article discusses the problems of achieving energy efficiency in residential low-rise housing construction within the framework of the resource-saving technologies use at the federal and regional levels. The need to solve these problems is due to the fact that the industry and transport development, as well as the accompanying increase in energy consumption, including the consumption of end consumers, have led to an acute mankind dependence on energy resources. The increase in energy demand with the simultaneous complication and rise in the cost of energy production, as well as the aggravation of global environmental problems have made energy conservation and energy efficiency the most important development areas in many countries of the world.
Business processes engineering for organizing the construction objects’ design
Authors: Fil Olga
Published: July 2021

The article is devoted to the engineering of business processes for organizing project activities. Engineering of the design organization aims to develop, introduce the new methods and model business processes for planning activities, carry out the engineering surveys, search for the most optimal design solutions that will achieve the best quality, taking into account all possible potential design problems. The author examines the scheme of business processes for organizing the design of construction projects, which will improve the development quality of design and estimate documentation and the applied design solutions’ level.
Methodological approaches to assessing the technical and economic efficiency of the building materials and structures’ use
Authors: Akulova Inna , Slavcheva Galina , Simonov Dmitry
Published: July 2021

The technical and economic efficiency actual problem of the use of building materials, products and structures is considered. Taking into account the purpose, a grouping of building materials was carried out according to eight nomenclature groups of structural, structural and heat-insulating, heat-insulating, acoustic, finishing, waterproofing and roofing materials, as well as the materials for special and general purposes. It is proposed to assess the technical and economic efficiency of building materials that form various nomenclature groups on the basis of two methodological approaches. The first approach should be applied to the building materials with one pronounced functional property, and the second - for the materials with several properties, the priority of which is not obvious. The calculations are carried out according to the criterion of the maximum units of useful effect due to the use of materials per unit of associated costs. In the second case, it is advisable to use the expert assessments to determine the significance of functional properties. Methodical recommendations for the technology of their implementation are provided.
The road infrastructure development impact on the economy of the region
Authors: Lykova Оlesia
Published: July 2021

The subject of the research is the road infrastructure development; the purpose of the study is to analyze the road network of the region as an element of its road infrastructure, to analyze the development of the road infrastructure using quantitative and qualitative criteria based on the regional road network current state assessment (using the example of the Krasnodar Territory). The construction and reconstruction of a capital construction object - highways will lead to an improvement in the conditions for the implementation of transport links, a decrease in accidents and an increase in traffic capacity, which will increase the circulation speed on this road section, and, as a result, reduce transport costs.
Prerequisites for the creation of building materials unified information base as a tool for the construction products’ actual cost formation
Authors: Zvereva Elena , Nemchaninova Maria , Tsarionova Yulia
Published: July 2021

The study is devoted to the issues of determining the cost of building materials, affecting the calculation of actual construction cost. These issues are of particular relevance, since there is a reform of the system of pricing and estimated rationing in construction at present, which fundamentally affects the construction actual and reliable cost determination. The proposed federal state information system of pricing in construction, as an electronic resource, a unified base for the cost formation of the building materials involved in the construction products’ estimated cost formation.
Study of the Ardon deep fault spatial position using high-precision gravity and magnetic measurements
Authors: Zaalishvili Vladislav , Kanukov Aleksandr , Persaeva Zarina , Shmanatov Georgi
Published: July 2021

Gravity prospecting (gravimetry) is one of the geophysical methods for studying the upper part of the Earth crust. To study the spatial position of the Ardon deep fault, the studies on the gravitational field gradient change have been carried out. A site along the road of Arkhonskaya - Dur-Dur was chosen as a profile. According to the obtained results, the greatest deviation from the average value is observed on the section from the 18th to the 36th kilometer. At the same time, there are areas with the values close to the average. This may indicate the presence of several “branches” of the fault. A similar profile was traversed using a magnetometer in order to compare the results with the data obtained by the gravimeter. According to the geomagnetic field modulus values, two areas are also singled out. Probably these areas are the extensions of the Ardon deep fault “branches”, found in early studies on the Upper Zgidprofile-Dzhimidon field with the help of the micro-seismic sounding method (MSM). According to the obtained data, it is possible to conclude that the gravimetric measurements, as well as the magnetic ones, allow determining the places of the probable spatial location of the faults. For a more detailed study of the Ardon deep fault, its further study with the help of MSM is proposed.
Fundamentals of the philosophical content methodology on the creation and development of a class of natural and technical systems in water management construction
Authors: Bondarenko Vladimir , Ylyasov Alla-Brerdi , Semenova Elena , Shtavdaker Maria
Published: July 2021

The main purpose of this article is to assess the philosophical, categorical concept meaning of the notions “system”, “system approach” and “system research” in the new class of natural and technical systems (NTS) “Natural Environment - Activity Object– Population” (“NE – AO - P”), which have received theoretical and practical application in economic and other activities related to the use of water resources in almost all technological processes of industrial and agricultural production, in electric energy generation at hydroelectric power plants, pumped storage hydro stations, nuclear power plants, thermal power plants and regional power stations, in water supply of urban farms, settlements and other areas. In accordance with this concept in the considered branch of economic activity it is necessary to find a certain place of this concept in the general process of developing the natural-technical systems class theoretical foundations. One of the scientific thinking formations features in the creation of a new class of natural and technical systems is the wide distribution of system research related to the use of water resources in various sectors of economic activity. The concept of “system”, “system research”, “system approach”, “system analysis” and other “system” concepts are widely used today, primarily in scientific and technical disciplines — general systems theory. They serve in these disciplines as an important conceptual basis for theoretical constructions and for the practical application of new scientific ideas and achievements. At the same time, the use of system concepts is becoming increasingly widespread in all previously established fields of science, including in water management science related to the use of water resources and technology. The concepts of “system” and “system approach” have already gained the status of general scientific and general technical concepts.
Environmental efficiency investigation of a gas turbine unit
Authors: Legkii Alexander , Karapuzova Natalya , Kudashev Alexei , Zlobin Vladimir , Vlasova Oksana
Published: July 2021

A method for purifying the gas-air mixture of a gas turbine unit and a waste-heat boiler is considered [1-3]. This work describes the principle of a gas-turbine plant and a waste-heat boiler operation using a catalytic afterburner, with the help of which a more complete process of carbon dioxide and nitrogenous compounds release occurs. Also, as a result of the exhaust gas-air mixture deeper cleaning process, there is a decrease in emissions within the maximum admissible concentrations (MAC), namely, by the amount of nitrogen and carbon oxides [4–7]. That allows to reduce the number of harmful substances, oxides of nitrogenous and carbon compounds, emitted into the environment. A scheme for cleaning a catalytic afterburner using rotary mesh devices, followed by disposal of carbon deposits and soot substances from the cleaning chamber is shown. This makes it possible to perform a stable ion exchange process, reducing the exhaust gases combustion products amount. It is proposed in this article to use mesh devices in the afterburner, treated with active substances by the method of ion implantation, as one of the most promising methods for modifying mesh surfaces. These processes occurring when the gas-air mixture passes through the afterburner, can reduce MAC emissions for various options for utilizing the discharge fuel mixture of a gas turbine unit (GTU) and heat supply to the waste heat boiler.
Assessment of environmental safety in the influence zone of the current Zelenchukskaya HPP-PSPP and Krasnogorsky HPP-1, HPP-2 under construction in the area of Ust-Dzhegutinsky reservoir location
Authors: Bondarenko Vladimir , Ylyasov Alla-Brerdi , Semenova Elena , Mirzoev Marat , Shtavdaker Maria
Published: July 2021

“Environmental safety” in the considered spatial limits of the basin geosystem of Upper Kuban (Fw = 11.0 * 103 km3, W lit.=3.3*103 km3, Watm.=110 * 103 W BGUK =124.3*103 km3) is about 21.4% of the spatial limits of the Kuban River, where water resources are formed according to the average long-term data of about 3.0 km3, which are used in various sectors of economic activity, including the generation of electric energy at the Zelenchukskaya HPP-PSPP and the Krasnogorsk HPP-1 and HPP-2 under construction with an installed capacity of up to 25 MW, located below the Zelenchukskaya HPP-PSPP target and above the target (12 km) Ust-Dzhegutinsky reservoir. Such placement of the Zelenchukskaya HPP-PSPP and the Krasnogorsk HPP-1 and HPP-2 under construction on a 15 km long section of the Kuban Riverbed has determined a highly active zone of influence (IV), which is caused by a change in the natural hydrograph of the Kuban River, with the formation of an unstated hydraulic regime of the channel flow movement on the considered section of the river to the Ust-Dzhegutinsky reservoir. The relentless changes in the water level in the Ust-Dzhegutinsky reservoir affect the pressure safety front structures, the functional operation of the water intake hydroelectric complex in the Bolshoy Stavropol Canal (BSC) and the hydraulic operation of the BSC. To assess the “environmental safety” level, it became necessary to develop a mathematical model of the functional operation influence of the Zelenchukskaya HPP-PSPP and the Krasnogorsk HPP-1 and HPP-2 under construction on the Ust-Dzhegutinsky reservoir operation level modes.
Comprehensive assessment of the dust environment at the construction industry enterprises
Authors: Meskhi Besarion , Evtushenko Аleksandr , Azarov Valeriy , Zhukova Natalia
Published: July 2021

Most technological lines for the production of building materials, products and structures are accompanied by dustemission at almost all stages of their production. In the absence or imperfection of aspiration systems, the concentration of dust in the working area air can be many times higher than the standard values. In this case, unfavorable working conditions are most often caused by an increased concentration of dust in the air of industrial premises. Assessment of the dust environment at industrial enterprises, as a rule, is understood as the study of air in working areas, the power of dust emissions into the atmosphere, as well as the efficiency of dust cleaning devices [1].
Comprehensive improvement of energy efficiency and environmental friendliness of a solid fuel boiler house
Authors: Kondratev Roman
Published: July 2021

Measures to improve the energy efficiency of boiler houses must be carried out in a complex, taking into account the interconnection of all obtaining heat energyprocesses, their automation and greening. A number of experiments have been carried out on UHFheating, drying and subsequent ignition of various types of solid fuels. Duration determinedUHF-impact and distribution of temperatures on the fuelsurface, depending on its moisture content and fraction. It is proposed to use a pre-combustion device to increase the energy characteristics of fuel with a high moisture content (up to 80%) by combined heating of an electromagnetic fieldUHFand convective thermal - flue gases, as well as a condensing air heater. The results of the pre-combustion device usefor combined heating are: an increase in the drying solid fuelefficiency, an increase in its combustionheat. Homogenized fuel was obtained from low-grade cheap solid fuel with a high moisture content (wood waste), which in its energy characteristics is not inferior to expensive pellets. The joint work of the developed pre-furnace design and the condensing air heater allows: to determine the efficiency factor of a boiler plant, reduce fuel consumption, involve wood waste and low-calorie fuel with a high moisture content (up to 80%) in the fuel balance of boiler houses, recycle and reuse the heat of flue gases, reduce the concentration of corrosive substances in flue gases and condensate, which allows use it as make-up and process water.
Shipping policy of agri-food products and the formation of food markets in Georgia
Authors: Kharaishvili Eteri , Gechbaia Badri , Erkomaishvili Gulnaz , Lobzhanidze Manana , Natsvlishvili Ia
Published: July 2021

The article evaluates an importance of shipment in economic growth and the development of food markets. Delays caused in shipment of agri-food products due to the COVID-19 pandemic are analyzed, problems in logistics are identified. It is argued that by identifying challenges in the shipment system and developing effective policy mechanisms, it is possible to create food markets that meet the changing requirements. The qualty of impact-emergency matrix identifies challenges in food shipment policy: weak political support, legislative vacuum on shipping and food market standards, non-compliance of regulatory rules with regulations of other countries, low level of digitalization of shipments, policies to maintain food prices in case of increase in shipment costs, etc. The article concludes that the correlation between food production and its shipment rates is positive, however, insufficient to impact economic growth. Pursuing a transport-stimulating policy will lead to the diversification of the food markets, especially in European markets. Considering the development of the food market and the challenges identified in the field of shipment policy, recommendations have been developed towards policy priorities and directions of the development of food markets.
Methodical approach to the choice of the variant of the shipbuilding company restructuring
Authors: Iefimova Ganna , Labartkava Andrei , Pashchenko Oleksiy
Published: July 2021

The issues of the resources use optimizing aimed at a shipbuilding company restructuring are considered, which is the main prerequisite for its effectiveness. The aim of this study is to develop a methodical approach to substantiation of the of the variant of the shipbuilding company restructuring on the basis of optimization-simulation model of its value estimation, which will take into account the algorithmically set conditions regarding the financing scheme, the type of restructuring, technological and economic relations in the system. The task of deciding on the shipbuilding company restructuring and the choice of a specific restructuring project refers to the optimization tasks of long-term planning. The limitations of the mathematical model are the company resources, which are allocated for restructuring. The main optimization criteria are maximizing net present value or minimizing the restructuring cost. The generated optimization model is designed to assess the amount of attracting for restructuring own and borrowed funds. Simulation model provides the cash flows construction. Restrictions on ensuring financial realization reflects the cash flow balance for all activities. The problem solution is achieved on the basis of an interrelated optimization, simulation models and procedures set for the formation, selection and approval of management decisions.
ctDNA-Monitoring beim frühen Brustkrebs
Authors: Arnheim Katharina
Published: July 2021

Der Nachweis von zirkulierender Tumor-DNA (ctDNA) nach neoadjuvanter Chemotherapie mit oder ohne Pembrolizumab wurde in der Studie I-SPY 2 bei Hochrisikopatientinnen mit frühem Brustkrebs als Biomarker für Ansprechen und fernmetastasenfreies Überleben (RFS) identifiziert.
Pyrocarbon Implant for Trapeziometacarpal Arthritis: Mid-term Clinical and Radiological Results
Authors: Ribeiro Elisabete , Ribau Melanie , Ribeiro Juvenália , Varanda Pedro , Rodrigues Luis Filipe
Published: July 2021

Pyrolytic carbon implants for trapeziometacarpal (TMC) arthritis have been extensively studied, but there is still discrepancy in the literature concerning the mid-term functional results. Our group describes the clinical and radiological results after five years of surgical management of TMC arthritis with Pyrodisk (Integra Life Sciences, Plainsboro, NJ, US). A total of 19 patients (2 males and 17 females) aged 56.45 ± 5.95 (range: 44 to 67) years were reviewed with a mean follow-up of 74.05 ± 14.43 (range: 60.00 to 105.83) months. At the final follow-up, the score on the Visual Analogue Scale (VAS) for pain was of 1.76 ± 2.05, the average score on the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire was of 22.73 ± 22.33, and all functional parameters were above the 90% barrier of the contralateral side. The progression of radiolucency was 89% at 1 year and 11% at 5 years of follow-up respectively, but it was not related to the clinical outcomes. The prevalence of subluxation (around one-fourth of the center of the implant) was of 24% in asymptomatic patients, and dislocation was not observed. The overall survival of the implant was of 89%. Revision took place in 11% of the cases due to persistent pain and implant breakage after direct impact. More than 75% of the patients were very or highly satisfied with the treatment. In conclusion, Pyrodisk enabled us to obtain good functional mid-term results, with an acceptable survival of the implant and low risk of dislocation. Radiological findings do not necessarily translate into clinical symptoms.
Digital Glomus Tumor: Bibliographic Review of the Studies Published over the Past 10 Years
Authors: Hernández Victoria , Lena Tania , Camacho Eliana , Craviotto Matías
Published: July 2021

Glomus tumors are a mostly benign neoplasm that constitutes less than 4% of upper-limb soft-tissue tumors. Its unspecific clinical presentation, added to its low frequency, leads to a late diagnosis.

The objective of the present study is to update the clinical-paraclinical approach and the surgical technique used in the treatment.

We carried out a literature review from 2014 to 2019 on digital glomus tumor in the hand in adult patients using the PubMed search engine.

In most of the publications analyzed, the diagnosis was clinical, with a delay of 1 to 10 years. Plain radiography is the most requested study; of the 16 articles reporting its indication, only half evidenced compatible changes. Magnetic resonance imaging (MRI) was requested in 15 articles, presenting normal results in 3 of them. The treatment of choice was surgical excision using a transungual approach. Only 4 articles report recurrence after excision.

Although there is diversity in the approach to these tumors, we conclude that the diagnosis is clinical, and the treatment surgical, and there is no consensus regarding the paraclinical indication. The information available comes mainly from case reports, publications that contribute to the generation of evidence for the clinical practice in rare diseases such as this one.
Dominant dynamics for a class of singularly perturbed stochastic partial differential equations with quadratic nonlinearities and random Neumann boundary conditions
Authors: Lei Ting , Chen Guanggan
Published: July 2021

This work concerns the effective approximation for a class of singularly perturbed stochastic partial differential equations driven by a sufficiently small multiplicative noise with quadratic nonlinearities and random Neumann boundary conditions. By splitting the solution into two parts in the finite dimension kernel space and its complement space with some suitable multi-scale argument, it derives rigorously the dominant dynamics, which captures the essential dynamics of the original system as a singular parameter is enough small.
In situ microscopy for plasma erosion of complex surfaces
Authors: Ottaviano Angelica , Thuppul Anirudh , Hayes John , Dodson Chris , Li Gary Z. , Chen Zhitong , Wirz Richard E.
Published: July 2021

A novel method for the in situ visualization and profilometry of a plasma-facing surface is demonstrated using a long-distance microscope. The technique provides valuable in situ monitoring of the microscopic temporal and morphological evolution of a material surface subject to plasma–surface interactions, such as ion-induced sputter erosion. Focus variation of image stacks enables height surface profilometry, which allows a depth of field beyond the limits associated with high magnification. As a demonstration of this capability, the erosion of a volumetrically featured aluminum foam is quantified during ion-bombardment in a low-temperature argon plasma where the electron temperature is ∼7 eV and the plasma is biased relative to the target surface such that ions impinge at ∼300 eV. Three-dimensional height maps are reconstructed from the images captured with a long-distance microscope with an x–y resolution of 3 × 3 μm2 and a focus-variation resolution based on the motor step-size of 20 μm. The time-resolved height maps show a total surface recession of 730 μm and significant ligament thinning over the course of 330 min of plasma exposure. This technique can be used for developing plasma-facing components for a wide range of plasma devices for applications such as propulsion, manufacturing, hypersonics, and fusion.
Multi-energy reconstructions, central electron temperature measurements, and early detection of the birth and growth of runaway electrons using a versatile soft x-ray pinhole camera at MST
Authors: Delgado-Aparicio L. F. , VanMeter P. , Barbui T. , Chellai O. , Wallace J. , Yamazaki H. , Kojima S. , Almagari A. F. , Hurst N. C. , Chapman B. E. , McCollam K. J. , Den Hartog D. J. , Sarff J. S. , Reusch L. M. , Pablant N. , Hill K. , Bitter M. , Ono M. , Stratton B. , Takase Y. , Luethi B. , Rissi M. , Donath T. , Hofer P. , Pilet N.
Published: July 2021

A multi-energy soft x-ray pinhole camera has been designed, built, and deployed at the Madison Symmetric Torus to aid the study of particle and thermal transport, as well as MHD stability physics. This novel imaging diagnostic technique employs a pixelated x-ray detector in which the lower energy threshold for photon detection can be adjusted independently on each pixel. The detector of choice is a PILATUS3 100 K with a 450 μm thick silicon sensor and nearly 100 000 pixels sensitive to photon energies between 1.6 and 30 keV. An ensemble of cubic spline smoothing functions has been applied to the line-integrated data for each time-frame and energy-range, obtaining a reduced standard-deviation when compared to that dominated by photon-noise. The multi-energy local emissivity profiles are obtained from a 1D matrix-based Abel-inversion procedure. Central values of Te can be obtained by modeling the slope of the continuum radiation from ratios of the inverted radial emissivity profiles over multiple energy ranges with no a priori assumptions of plasma profiles, magnetic field reconstruction constraints, high-density limitations, or need of shot-to-shot reproducibility. In tokamak plasmas, a novel application has recently been tested for early detection, 1D imaging, and study of the birth, exponential growth, and saturation of runaway electrons at energies comparable to 100 × Te,0; thus, early results are also presented.
Frequency shift algorithm: Design of a baseband phase locked loop for frequency-domain multiplexing readout of x-ray transition-edge sensor microcalorimeters
Authors: van der Hulst Paul , van der Kuur Jan , Nieuwenhuizen Ad , Vaccaro Davide , Akamatsu Hiroki , van Winden Patrick , van Leeuwen Bert-Joost , den Herder Jan-Willem
Published: July 2021

The Transition-Edge Sensor (TES) is an extremely sensitive device, which is used to measure the energy of individual x-ray photons. For astronomical spectrometry applications, SRON develops a frequency domain multiplexing readout system for kilopixel arrays of such TESs. Each TES is voltage biased at a specific frequency in the range of 1–5 MHz. Isolation between the individual pixels is obtained through very narrow-band (high-Q) lithographic LC resonators. To prevent energy resolution degradation due to intermodulation line noise, the bias frequencies are distributed on a regular grid. The requirements on the accuracy of the LC resonance frequency are very high. The deviation of the resonance frequencies due to production tolerances is significant with respect to the bandwidth, and a controller is necessary to compensate for the LC series impedance. We present two such controllers: a simple orthogonal proportional–integral controller and a more complex impedance estimator. Both controllers operate in baseband and try to make the TES current in-phase with the bias voltage, effectively operating as phase-locked loops. They allow off-LC-resonance operation of the TES pixels while preserving the TES thermal response and energy resolution. Extensive experimental results—published in a companion paper recently—with the proposed methods show that these controllers allow the preservation of single pixel energy resolution in multiplexed operation.
A compact narrow-width combined antenna for the radiation of the UWB electromagnetic pulses
Authors: Wang Shao-fei , Xie Yan-zhao , Qiu Yang-xin
Published: July 2021

In this article, a Narrow-Width Combined Antenna (NWCA) is proposed for the compact design of high-power ultra-wideband (UWB) systems. The dependence of performances on three dimensions of the combined antenna is investigated so as to minimize its size with a given excitation. It indicates that the working process of the combined antenna can be divided into two stages: (1) energy transmitted from the feeding point to the aperture by the TEM horn structure, and during this stage, the passband is determined by the effect of the impedance taper, which is related to the length and aperture impedance of the antenna, and (2) energy radiated to the free space from the aperture, during which the height of the aperture is the dominant factor. Therefore, the three dimensions of the combined antenna can be appropriately adjusted to make the antenna more compact. Thus, the NWCA is designed by reducing the width and making a slight compensation in height and/or length. Compared with the conventional cubic antenna, the aperture area of the developed NWCA is reduced by 47%, whereas the amplitude of the radiating field only reduces by 2.5% with the given pulsed excitation at the cost of a slight decrease in the pulse duration. It demonstrates that the NWCA is an effectively compact design for the combined antenna in the application of the radiation of the high-power UWB pulse.
Extension of single-crystal x-ray spectropolarimetry with cubic crystals beyond perfect polarization-splitting geometries
Authors: Presura R. , Wallace M. S. , Haque S. H. , Pohl I. , Lake P. W. , Wu M.
Published: July 2021

The single-crystal spectropolarimeter envisioned by Baronova and Stepanenko splits an incident x-ray beam into two beams with mutually orthogonal linear polarizations by using simultaneous reflections at the perfectly polarizing 45° Bragg angle on certain pairs of internal planes in hexagonal or cubic crystals. These planes intersect along a threefold symmetry axis, making a 120° angle with each other, and are typically symmetric with respect to the crystal surface. In practice, the wavelength of the diagnostic x-ray lines does not exactly satisfy Bragg’s law for the crystal in the ideal polarizing orientation, so the extinction of reflections is incomplete. Accepting this limitation, this paper shows that for cubic crystals, other pairs of internal planes exist that satisfy the polarization requirements approximately. Typically, they are accessible from the perfect polarization-splitting geometry by small rotations of the crystal. This paper includes examples of such planes for cubic crystals with {110} and {211} surface cuts.
Nb-doped ZrxSn1−xO2: Experimental and first-principles study
Authors: Ye Pan , Li Mingkai , Fu Wang , Wei Haoran , E Wentao , Xiao Xinglin , He Yunbin
Published: July 2021

Ultra-wide bandgap semiconductors with exceptional advantages have potential use in ultrahigh power, ultrahigh frequency devices, and other applications. In this paper, a series of high-quality Nb-doped ZrxSn1−xO2 (Nb:ZrxSn1−xO2) alloy epitaxial films were prepared on c-plane sapphire substrates by pulsed laser deposition. A greater proportion of Zr successfully widened the optical bandgap of SnO2 up to 4.70 from 4.28 eV. Interestingly, although Nb is a common n-type dopant for SnO2, the conductivity of Nb:ZrxSn1−xO2 decreased with increasing Zr content. The greater activation energy Ea of the films with more Zr contents was determined by variable resistance measurements and rationalized by the first-principles calculations. The higher Zr content leads to a lower conductivity in the films. This is because the electronegativity of Zr is smaller than that of Sn and Nb, making it easier for O to attract electrons from Zr and Nb donating less electrons with increasing Zr content. It leads to more electrons filling the Nb 4d orbital and brings the donor level further down from the conduction band minimum. However, Nb:ZrxSn1−xO2 with a low Zr content of x = 0.1 has good electrical conductivity, with a carrier density of 5.426 × 1020 cm−3 and a resistivity of 7.89 × 10−3 Ω cm, and simultaneously a broadened bandgap of 4.4 eV. Therefore, Nb can act as an effective n-type dopant for ZrxSn1−xO2 with proper Zr content, making Nb-doped ZrxSn1−xO2 promising for developing ultraviolet-transparent conductive electrodes.
Reservoirs, Fick law, and the Darken effect
Authors: De Masi A. , Merola I. , Presutti E.
Published: July 2021

We study the stationary measures of Ginzburg–Landau (GL) stochastic processes, which describe the magnetization flux induced by the interaction with reservoirs. To privilege simplicity to generality, we restrict to quadratic Hamiltonians where almost explicit formulas can be derived. We discuss the case where reservoirs are represented by boundary generators (mathematical reservoirs) and compare with more physical reservoirs made by large-infinite systems. We prove the validity of the Fick law away from the boundaries. We also obtain in the context of the GL models a mathematical proof of the Darken effect, which shows uphill diffusion of carbon in a specimen partly doped with the addition of Si.
Efficient hybrid acceleration scheme for generating 100 MeV protons with tabletop dual-laser pulses
Authors: Isayama S. , Chen S. H. , Liu Y. L. , Chen H. W. , Kuramitsu Y.
Published: July 2021

Proton beams with energies beyond 100 MeV are essential for a wide range of applications, including modern cancer therapies. The generation of high-energetic protons beyond 100 MeV in experiments using PW-level laser pulses normally requires laser energies of 10–200 J. We propose an efficient hybrid scheme using tabletop (tens of TW) dual-laser pulses with laser energy of a few Joules with tandem solid density and near-critical density targets. The results of a 2D particle-in-cell simulation show that the combination acceleration scheme of the radiation pressure acceleration (RPA), laser wakefield acceleration (LWFA), and target normal sheath acceleration (TNSA) with the dual-pulses can considerably enhance the maximum proton energy to ∼220 MeV, which is nearly three times of the proton energy achieved by the RPA or the RPA-LWFA-TNSA using a single laser pulse.
PDE-guided reservoir computing for image denoising with small data
Authors: Jeon Jongha , Kim Pilwon , Jang Bongsoo , Kim Yunho
Published: July 2021

While network-based techniques have shown outstanding performance in image denoising in the big data regime requiring massive datasets and expensive computation, mathematical understanding of their working principles is very limited. Not to mention, their relevance to traditional mathematical approaches has not attracted much attention. Therefore, we suggest how reservoir computing networks can be strengthened in combination with conventional partial differential equation (PDE) methods for image denoising, especially in the small data regime. Given image data, PDEs generate sequential datasets enhancing desired image features, which provide the network with a better guideline for training in reservoir computing. The proposed procedure, reservoir computing in collaboration with PDEs (RCPDE), offers a synergetic combination of data-driven network-based methods and mathematically well-established PDE methods. It turns out that RCPDE outperforms both the usual reservoir computing and existing PDE approaches in image denoising. Furthermore, RCPDE also excels deep neural networks such as a convolutional neural network both in quality and in time in the small data regime. We believe that RCPDE reveals the great potential of reservoir computing in collaboration with various mathematically justifiable dynamics for better performance as well as for better mathematical understanding.
Effect of dual vortex shedding on airfoil tonal noise generation
Authors: Yang Y. , Pröbsting S. , Liu Y. , Zhang H. , Li C. , Li Y.
Published: July 2021

To improve understanding of dual vortex shedding over a trailing edge with regard to airfoil tonal noise generation, synchronized velocity and noise measurements are conducted on a NACA (National Advisory Committee for Aeronautics) 0012 airfoil at angle of attack near zero and a Reynolds number of 220 000. Instantaneous flow fields obtained by particle image velocimetry show the development of separated shear layer, vortex roll-up, and vortex breakup near the airfoil trailing edge. The time-averaged flow fields feature separation bubbles on both sides, and the root mean square values of streamwise velocity fluctuations show triple peak structures. The velocity spectra agree well with the noise spectra in terms of broadband humps and discrete tones. Through proper orthogonal decomposition (POD) analysis, the most energetic modes are identified, which represent global structures in the flow field. The trailing edge noise being an integral effect of the velocity fluctuation near the trailing edge, the POD analysis provides an alternative view for understanding the noise generation mechanism. The first and second modes are dominated by out-of-phase vortex shedding along the airfoil surface and in the near wake, which dominates the high amplitude noise emission process. The third and fourth modes represent in-phase vortex shedding, which dominates the low amplitude noise emission process. The noise source region is determined by the correlation between the velocity and sound pressure, which shows approximately the same periodic pattern as the first and second POD modes.
Bipolar conductivity in ferroelectric La:HfZrO films
Authors: Perevalov Timofey V. , Gismatulin Andrei A. , Gritsenko Vladimir A. , Prosvirin Igor' P. , Mehmood Furqan , Mikolajick Thomas , Schroeder Uwe
Published: July 2021

Lanthanum-doped HfZrO is considered as the ferroelectric material for capacitor structures used in one-transistor-one capacitor nonvolatile memory cells for the development of new generation nonvolatile random-access memory. Here, different capacitor structures are characterized by x-ray photoelectron spectroscopy electrically to determine the electron and hole contribution to the conductivity in these capacitor structures. Experiments related to the minority carrier's injection and charge transport from an n-Si and a p-Si substrate into a lanthanum-doped HfZrO layer show that the conductivity is bipolar. Electrons are injected into La:HfZrO from a negatively biased contact, and accordingly, holes are injected from a positive voltage biased electrode.
The influence of polarization misalignment for modulation transfer spectrum in atom gravimeter
Authors: Zhou Hang , Luo Qin , Chen Le-Le , Zhou Min-Kang , Hu Zhong-kun
Published: July 2021

The accuracy of atom gravimeters is directly related to the Raman laser, which is used to manipulate the atomic wave packet, and the frequency of the Raman laser could be affected by temperature when the laser polarization is not along the preferred axis of the electro-optic crystal employed in the modulation transfer spectrum (MTS). This effect has been researched by modulating the laser polarization in the MTS in this work. The experimental results show that both the laser frequency and gravity measurement results have a sinusoidal dependence on temperature, and the period of the fluctuation is 0.8 °C. The systematic effect can reach 12.4 μGal when the polarization misalignment is 15°, which is a remarkable contribution to the absolute gravity measurement. The amplitude of this effect could be reduced by adjusting the laser polarization to the crystal’s preferred axis. According to the result, the included angle between the laser polarization and the crystal’s preferred axis should be smaller than 5° if 2 μGal accuracy is required.
Thermodynamics and self-organization of strongly coupled Coulomb clusters: An experimental study
Authors: Hariprasad M. G. , Bandyopadhyay P. , Arora Garima , Sen A.
Published: July 2021

In this experimental work, the thermodynamics and self-organization of classical two-dimensional Coulomb clusters are studied as a function of the cluster size. The experiments are carried out in a DC glow discharge argon plasma in the dusty plasma experimental device for clusters with different number of particles. Hexagonal symmetry around each individual particle is quantified using the local orientational order parameter (|ψ6|) for all the configurations. The screened Coulomb coupling parameter, which plays a key role in determining the thermodynamic nature of a Coulomb cluster, is estimated using Langevin dynamics and found to be sensitive to the number of particles present in the cluster. In addition, the process of self-organization and the dynamics of individual particles of the cluster as it changes from a metastable state to the ground state are examined through the estimation of dynamic entropy. Our findings suggest an intimate link between the configurational ordering and the thermodynamics of a strongly coupled Coulomb cluster system—an insight that might be of practical value in analyzing and controlling the microdynamics of a wider class of finite systems.
On the temperature and density dependence of dislocation drag from phonon wind
Authors: Blaschke Daniel N. , Burakovsky Leonid , Preston Dean L.
Published: July 2021

At extreme strain rates, where fast moving dislocations govern plastic deformation, anharmonic phonon scattering imparts a drag force on the dislocations. In this paper, we present calculations of the dislocation drag coefficients of aluminum and copper as functions of temperature and density. We discuss the sensitivity of the drag coefficients to changes in the third-order elastic constants with temperature and density.