bluuebunny/crossref_metadata_2025 huggingface dataset:
New high-entropy oxide phases with the perovskite structure
Authors: Zaitseva O V , Gudkova S A , Trofimov E A , Zhivulin V E , Punda A Yu , Starikov A Yu , Vinnik D A
Published: January 2021

Results of studying the structure and chemical composition of perovskite phases synthesized by solid-state sintering in multicomponent oxide systems: (Ba,Sr,Ca,Mg,Pb)(Ti,Zr)O3, (Ba,Sr,Ca,Mg,Pb)(Ti,Zr,Hf)O3, (Ba, Sr, Ca,Mg,Pb)(Ti,Zr,Hf, Sn)O3, and (Ba,Sr,Ca,Mg,Pb)(Ti,Zr,Hf,Sn,Mn)O3 are presented. The chemical composition of the obtained samples was investigated using a JEOL JSM7001F scanning electron microscope equipped with an Oxford INCA X-max 80 energy-dispersive X-ray fluorescence spectrometer. The structure was studied with a Rigaku Ultima IV powder X-ray diffractometer. It was demonstrated the possibility of obtaining a high-entropy perovskite phase. Elements (Ba, Sr, Ca, Ti, Zr, Hf, Sn), which can form the high-entropy perovskites have been determined, as well as the elements (Pb, Mg, Mn), which, for various reasons, are hardly incorporated in the high-entropy perovskites.
Process Improvement Using Six-Sigma (DMAIC Process) in Bearing Manufacturing Industry: A Case Study
Authors: Bhargava Manish , Gaur Sanjay
Published: January 2021

Propagation, development of technologies and increasing customer demands switch the approach of existing work in the industries. To overcome barricades, the six-sigma DMAIC (define, measure, analyse, improvement, control) approach is trendy along with being advantageous. This approach decreases the variation and set up the way for up gradation in the manufacturing companies. This paper contains the Six-Sigma DMAIC approach that was used to decrease the process variation of inner and outer races of ball bearing for enhancing product quality. Define phase of DMAIC approach begins by difficulty detection through the voice of internal and external customers. The later stage constitute of measuring the data of bearing parts of existing process. This stage followed by the analyze as well as improvement stage, where the Six-Sigma quality improvement tools i.e. statistical process control (SPC), Control charts, MINITAB 18.0 software, fish bone diagram along with significant study of alive process were imposed to identify root causes and minimizing process variability. The improvement stage minimized the assignable causes for variability. The control phase called to maintain the improved process till further improvement.

This work expected that the Six-Sigma DMAIC methodology was effective for increasing the sigma level, decreasing the value of standard deviation and also decreasing the expected part per million (PPM) out of specification limits. Values of capability indices i.e. (Cp, Cpk and Cpm) were improved. A Six-Sigma DMAIC methodology is well-known and is capable of playing an efficient role in manufacturing industry by reducing variability in the bearing part process.
Tolerance analysis of a GFET transistor for aerospace and aeronautical application
Authors: Lamberti P , Mura M La , Pasadas F , Jiménez D , Tucci V
Published: January 2021

Due to the high carrier mobility, graphene is considered a promising material for use in high-speed electronic devices in the post-silicon electronic era. Graphene high resistance to radiation and extreme temperatures makes the development of graphene-based electronics a key-enabling technology for aerospace, defence, and aeronautical applications. Nevertheless, achieving uniform device-to-device performance is still a challenge, and these fields require high reliability components. In particular, many critical issues remain to be solved, such as their reproducibility and guaranty of identical performances against possible variations of different manufacturing and environmental factors. In the present work, a model capable to take into account the physical characteristics linked to the production process of a Graphene Field-Effect Transistor (GFET) is exploited to carry out a tolerance analysis of process-related geometrical parameters on the device performance. The most influential parameters that affect the device behaviour are studied in order to enhance the fabrication yield.
Application of different Lagrangian Particle Tracking techniques for water impingement
Authors: Petrosino F. , De Rosa D. , Mingione G.
Published: January 2021

Water impingement on aerodynamic surfaces represents how much flow rate water mass impact on the surfaces, respect to total mass flow rate. This parameter, together with Liquid Water Content, is important in ice prediction since it defines water mass distribution on solid surface, by which depends several other problems like freezing fraction, anti-icing system, etc. In this work we focus on the lagrangian method to calculate droplets’ trajectory, comparing the results against 2D and 3D experimental data.
Design of a composite nose wheel for commercial aircraft
Authors: Wacker J-D , Laveuve D , Contell Asins C , Büter A
Published: January 2021

Innovative approaches for lightweight design of components can contribute significantly to reduced fuel consumption and emissions of future aircraft. Within the framework of the European aviation research program Clean Sky 2, an innovative design of an aircraft nose wheel for the A320 is developed using carbon fiber reinforced plastics (CFRP) in order to demonstrate a weight reduction potential of 27% compared to conventional designs. In the present paper, the approach of the development process and the final detailed design of the composite aircraft wheel as well as a manufacturing concept are presented, various design challenges are highlighted and the solutions developed to meet them are discussed. Within a concept phase different structural design principles for the wheel are analyzed, taking into account the challenging load cases during different phases of aircraft operation. The selected innovative design principle is further elaborated into a detailed design considering design challenges such as space, installation, and safety requirements, as well as integration of bearings, seals and joint solutions. Also, structural analysis of the composite components via FEA and experimental validation of the joints are discussed. In addition, the manufacturing concept for the complex wheel geometry via resin transfer molding (RTM) using carbon non-crimp fabrics is presented and an outlook on the future manufacturing and testing of wheel prototypes is given.
Robot deployed Laser-Ultrasonic NDT system for inspection of large aircraft structures
Authors: James Vicki , Carswell Dave , Riise J , Nicholson P. Ian , Graf Norbert , Huber Norbert , Gärtner Martin , Reitinger Bernhard , Scherleitner Edgar , Burgholzer Peter , Phipps Jon , Burns Dave , Incarnato Ciro
Published: January 2021

The mandatory Non-Destructive Testing (NDT) by the aerospace industry for both present and future generation hybrid aircraft using thick composite structures poses many challenges for traditional inspection techniques. Laser Ultrasonic Testing (LUT) deployed by a robot for inspection of modern aerospace composite components shows good promise. It is a non-contact method offering the possibility of fast scan times without the need for couplant. This paper presents the latest work-in-progress for the design and development of the system developed by the ACCURATe consortium. ACCURATe is an ongoing H2020 Clean Sky 2 part funded project to develop a laser ultrasound based NDT system prototype for fast and contactless testing of large carbon fibre reinforced polymer (CFRP) aircraft structures.

The approach is based on a non-contact laser generated and detected pulsed ultrasound technique with delivery of both the laser ultrasound excitation and detection pulses through flexible optical fibres. The backscattered light from the lasers is also collected into a fibre. The measurement head, which contains the two beam outputs and the light collection optics is raster scanned over the surface by a 6-axis robot arm. A balanced two wave mixing interferometer (B-TWM) is used for the demodulation of the ultrasonic waves.

The system has recently been used to scan a reference panel, and a scrap panel of fuselage, the latest test results are presented and show promising progress against the project objectives.
Aerial Stability Of An In-Flight Water Scooping System
Authors: Verhagen Mario , Timmermans Huub , den Brink Wouter van
Published: January 2021

Given operational restrictions of current firefighting aircraft, a novel concept is proposed within SCODEV. Launched within the Horizon 2020 Fast Track to Innovation framework, SCODEV considers a novel system that refills an aircraft’s water tanks during low altitude flight. The novel scooping system consists of a hose and a scoop that penetrate the water surface during low altitude flight. Though promising major benefits with respect to current firefighting aircraft, the design of such a novel scooping system poses significant and unique challenges. For safe and successful water scooping, it is paramount that the scooping system, consisting of the hose and scoop, maintains a stable shape when being lowered and at any extended position, that the hose maintains a desired shape with a sufficiently vertical attitude, and that the scoop maintains a desired attitude with respect to the airflow, before entering the water. Focusing on system prerequisites that allow for initiation of water ingestion, this paper does not consider system response during water ingestion, reel-in or fly-out. The hose and scoop are designed and assessed through simulations, taking into account the three aforementioned criteria. The scoop and hose are designed and assessed separately in the simulation environment. For the hose, quasi-dynamic aeroelastic analyses are performed by coupling the structural Abaqus solver with an external aerodynamic code and iterating for a hose shape in space. It is assessed whether the hose can maintain a stable shape while being lowered, and at full length. Secondly, it is assessed whether the hose can maintain a desired shape at full length, maintaining a sufficiently vertical attitude. For the scoop, aerial stability analyses have been performed using MSC Nastran. The scoop is designed to maintain a stable and desired orientation with respect to the oncoming airflow. Helicopter flight tests are performed to substantiate analytical results on hose and scoop stability, hose shape and scoop orientation. When the scoop and hose are tested separately, observed behaviour is in good agreement with simulation predictions; the hose remains stable and has a desired shape with sufficiently vertical attitude. The scoop similarly remains stable and maintains a desired orientation with respect to the incoming airflow. For the coupled system, system behaviour differs from analytical predictions. This highlights the need to consider the coupled system in the simulations instead of analysing both components separately.
2D optimization of a Small Horizontal Axis Wind Turbine blade using flow control techniques
Authors: Papadopoulos C , Kaparos P , Vlahostergios Z , Misirlis D , Yakinthos K
Published: January 2021

In this work, the optimization of the efficiency of a small horizontal axis wind turbine (SHWT) blade segment is presented. Typically, SHWTs have a radius of 1.5 to 3.5 m and a hub height of around 15 m from the ground. SHWTs operate in a relatively small Reynolds numbers range (up to 1.5x106) and are installed inside the atmospheric boundary layer. This operational environment is characterised by volatile air flow, making the flow over the blade prone to separation. In order to counter this flow behavior, a set of flow control techniques is introduced and studied. These techniques control the flow, either passively, solely by the inclusion of blade add-ons, or actively, by adding energy to the boundary layer. More specifically, two passive flow control techniques and one active flow control technique are modelled and tested on a wind turbine blade segment. The passive techniques implemented in this study are based on the use of vortex generators and tubercles. Vortex generators are small vanes attached vertically to the lifting surface and are widely used in aerospace applications with varying degrees of success. Tubercles, which is a novel flow control technique, are sinusoidal modifications of the blade’s leading edge. The original concept has been inspired from the characteristic flipper of the humpback whale (Megaptera Novaeangliae). Regarding the active flow control technique, a dielectric barrier discharge (DBD) plasma actuator (PA) is used, a technique that adds momentum on the local flow, close to the blade’s surface, by ionizing the air. The impact on the blade aerodynamic efficiency for each technique are evaluated and presented. The results from this evaluation show that flow control techniques can offer a considerable benefit to SHWT by improving the blade’s aerodynamic characteristics, i.e. by increasing the blade lift-to-drag ratio and thus, improving their critical performance efficiency factor.
A dynamic Immersed Boundary method for moving bodies and FSI applications
Authors: Capizzano Francesco , Sucipto Triyantono
Published: January 2021

The document describes the CIRA and IBK collaborative research during the European Project UHURA. The latter aims to characterize the dynamic unsteady flow due to the deployment of a high-lift device at approach/landing conditions. The present work is devoted to the comprehension of the unsteady phenomena during the device motion by means of a coupled fluid-structure interaction (FSI) approach. In particular, the CIRA in-house immersed boundary (IB) code is extended to treat moving bodies and dynamic mesh refinements with the goal of simulating compressible and viscous flows around moving/deforming objects.

The basic idea considers the motion of Lagrangian bodies through an inertial Cartesian mesh. Differently from classic moving-mesh approaches, the Cartesian cells do not move in space but rather they observe the solid walls crossing themselves. A moving least-square procedure (MLSQ) is used to build up a dynamic discrete forcing. The rigid body motion feature has been validated by simulating well-known benchmarks available in literature.

A proper interface for coupling the IB method with a finite-element (FEM) solver is developed in the framework of a partitioned approach. In particular, the shared platform drives the solution sequence and allows exploring different coupling strategies. The aim is to simplify and automatize the study of complex flows whose characteristics strongly depends on the structural properties of moving objects. The final application deals with the FSI simulation of a high-lift device during its deployment phase.
Progress towards simulation of Krueger device motion with Lattice Boltzmann Methods
Authors: Ponsin J , Lozano C
Published: January 2021

This paper presents preliminary results of the application of a Lattice-Boltzmann code to the prediction of the unsteady aerodynamics present during the deployment/retraction of a Krueger device. The present study has been performed within the EU-Project UHURA, which is dedicated to the validation of URANS and other unsteady flow simulation methodologies for the prediction of the flow on high lift devices designed for laminar wings. Several case setup issues are examined and verification with RANS is presented. Lessons learned during the first phase of the project are drawn.
Hybrid electric distributed propulsion overall aircraft design process and models for general aviation (FAST GA)
Authors: Ruscio J P , Jezegou J , Benard E , Pacheco A Gomez , Laonet P , Castilla R Alonso
Published: January 2021

In the frame of the European objectives in terms of CO2 emissions, the aeronautics is looking for a technological rupture to achieve them, in particular, the aircraft design domain pursuits this through the research of innovative architectures. One of these innovative configurations currently being explored includes the hybrid electric energy source (thermal/electric) for Distributed Electric Propulsion (DEP) architecture. This Paper details a code developed to size a general aviation aircraft at concept level, by only defining its top level requirements and the main architecture parameters. The code can manage both conventional and hybrid power source as well as concentred or distributed propulsion architectures in order to allow the user to evaluate and compare the feasibility and benefits respectively of these innovative architectures. This code is a branch of the code “FAST-CS25” (Future Aircraft Sizing Tool for conventional CS-25 type) held by ONERA/ISAE-SUPAERO. The presented work aims at the expansion of the FAST code to CS-23 conventional type, hybrid electric energy source, and distributed propulsion system configurations. Through this paper, the models and the main sizing loops for the concept design are described, but putting special emphasis on the distributed propulsion aerodynamics and wing mass estimation. These detailed models where validated with the NASA X-57 DEP aircraft satisfactory. The whole concept design loop of a hybrid energy aircraft was validated with the eGenius hybrid energy aircraft.
Concept of Operation for integrating RPAS into terminal airspace
Authors: Perez-Castan JA , Aznar Olmos J , Gómez Comendador F , Rodríguez-Sanz A , Arnaldo Valdes RM
Published: January 2021

Remotely Piloted Aircraft System (RPAS) is a capital issue for the majority of aviation actors nowadays. The integration of RPAS is an extremely demanding task that must be tackled by multiple standpoints: economic, social, technological or environmental among others. U-space is the answer from Europe to design the operation of multiple and different types of RPAS. U-space is a set of novel services designed to support efficient, safe and secure access to airspace, from the very low level to the upper airspace. This paper focuses on the terminal airspace to design the operational concept for the integration of RPAS in conjunction with conventional aircraft and general aviation. This work develops a holistic methodology to analyse the way RPAS integration affect crucial factors and tries to bring to the light different issues that can frustrate their integration. First, we focus on detailing the requirements specified by RPAS legislation. Second, all the requirements are gathered into different categories to perform further analysis. The categorisation identifies navigation, communication, surveillance, air traffic management and control, and safety as crucial categories (security is out of the scope of this study). The results provide for each category a proposal about how to solve the integration and implementation of RPAS in a TMA.
Integration of rule-based ‘Expert Systems’ on RPAS capable of Specific Category Operations within the U-space: an original mitigation strategy for operational safety risks
Authors: Bonfante F , Dalla Vedova M D L , Maggiore P , Grimaccia F , Filippone E
Published: January 2021

The use of RPAS for civil purposes is spreading across Europe and worldwide; Aviation Authorities are working to layout regulations to assure a safe and secure integration of RPAS with manned aircraft across both controlled and uncontrolled (below 500 Feet of altitude) airspace. Following the identification of a selection of safety risks potentially associated to RPAS Specific Category of operations, an original strategy of risks mitigation focused on rule-based ‘Expert Systems’, has been conceived and it is discussed in this work. The article recalls the main components of rule-based ‘Expert Systems’ that is the knowledge basis and the rules to instruct the ‘Expert system’. Then the work describes the implementation of the rules as statements derived from a safety risk matrix associated to RPAS capable of performing Specific Category operations within the U-space. Finally, the idea of integrating the ‘Expert System’ as a software module within RPAS functional architecture is presented and discussed. Such solution is deemed to be a valuable novelty for future implementations of advanced RPAS autopilots capable of recognizing and solving in flight/on ground operational safety risks in such a way to speed up the integration of RPAS into not segregated airspace and their market development.
Learning how to escape the unthinkable with virtual reality: the case of pilots’ training on emergency procedures
Authors: Lekea Dr. Ioanna K. , Stamatelos Dr. Dimitrios G. , Raptis Pantelis
Published: January 2021

The focus of this paper is the development of a digital escape room for pilots’ training in flight safety procedures. To this end, we will discuss the methodology we used in order to make sure that each stage of the evolution of our digital platform is safe and suitable for educational use. Therefore, we will analyse the first stages towards the construction and evaluation of the scenarios incorporated in our entirely digital escape room that is intended for the T-6A Texan II pilots’ education. Because of the educational character of the digital escape room, the theoretical background of our research is extremely important, since it provides the escape room with the educational aspect. As a result, for the narratives of our simulations and the development of our emergency cases, we used as our baseline the flight manual, the boldface procedures and the operating limitations of T-6A aircraft and we selected the categories of incidents/emergencies to be used as part of our virtual escape room. We, then, constructed the trial-run scenarios that we asked pilots to solve. Finally, we conducted extensive field research with the development and use of appropriate questionnaires and interviews to evaluate the realism of our scenarios. Based on the feedback we received from the field research, we will conclude this paper by discussing the limitations of this study, but also our ideas for future improvements and a timeline on our research progress, as well as on further developing our virtual escape room.
The effects of Virtual Reality technology application in the aircraft pilot training process
Authors: Dymora Pawel , Kowal Bartosz , Mazurek Miroslaw , Romana Sliwa
Published: January 2021

In this study, we focus on some problems related to virtual reality technology usage in supporting the educational process. The main goal is to obtain the optimal duration of exposure to virtual reality without the appearance of physiological problems for the user affected the achievement of teaching outcomes. Most of the characteristics of virtual reality software at the same time point out some issues in the areas of technological innovations, especially in the health context. The presented example of the VR environment’s training application shows the effectiveness of VR methods and their possibilities in training aircraft pilots. Teaching involving VR allowed to achieve, on average, as much as 90% correct answers, which in comparison with traditional methods resulted in an increase of 21 to 32.7% of correct answers in comparison with training using VR. The research confirmed that a critical challenge in the context of the broader use of VR in education is to appropriately adapt the learning materials and content to the technical requirements. Then, in certain areas, the use of VR is beneficial.
Tactical Runway Scheduling for Demand and Delay Management
Authors: Rodríguez-Sanz Álvaro , Cózar Pablo López , Pérez-Castán Javier A. , Comendador Fernando Gómez
Published: January 2021

Airports are limited in terms of capacity. Particularly, runways can only accommodate a certain number of movements (arrivals and departures) while ensuring safety and determined operational requirements. In such a constrained operating environment, any reduction in system capacity results in major delays with significant costs for airlines and passengers. Therefore, the efficient operation of airports is a critical cornerstone for demand and delay management of the whole air transportation system. Runway scheduling deals with the sequencing of arriving and departing aircraft at airports such that a predefined objective is optimized subject to several operational constraints, like the dependency of separation on the leading and trailing aircraft type or the runway occupancy time. Scheduling arrivals and departures at runways is a complex problem that needs to address diverse and often competing considerations among involved flights. In the context of the Airport Collaborative Decision Making (A-CDM) programme, airport operators and air navigation service providers require arrival and departure management tools that improve aircraft flows at airports. Airport runway optimization, as the main element that combines airside and groundside operations, is an ongoing challenge for air traffic management. By considering real airport performance data with scheduled and actual movements, as well as arrival/departure delays, we present a robust model together with an optimization algorithm, which incorporates the knowledge of uncertainty into the tactical operational step. Our model has been validated with real data from a large international European airport in different traffic scenarios. Results are compared to the actual sequencing of flights and show that the algorithm can significantly contribute to the reduction of delay, while adhering as much as possible to the operative procedures and constraints, and to the objectives of the airport stakeholders. Computational experiments performed on the case study illustrate the benefits of this arrival/departure integrated approach.
High mach number drag analysis of a modern lightweight launch vehicle
Authors: French Ainslie D , Schettino Antonio , Romano Luca
Published: January 2021

This paper presents predictions of pressure and frictional drag using on the individual components of the VEGA C Light Launch Vehicle propelled by a solid rocket motor over a hypersonic Mach number range from five to eight at nominal atmospheric conditions associated with the corresponding stage of the ascent trajectory. Both motor-off and motor-on conditions are simulated to isolate the motor-on effects. A series of simulations were also performed in off-nominal conditions by varying the Reynolds number and mass flow rate to examine the effects on drag under more extreme conditions. The results indicate that the differences between the motor-off and motor-on cases in nominal conditions are mainly due to base drag. With the motor-on the base pressure increases thereby reducing the total drag. In the off-nominal conditions, when the Reynolds number is increased there is a reduction in drag, and when the nozzle mass flow rate is decreased there is an increase in drag. Conversely, when the Reynolds number is decreased and the nozzle mass flow rate is increased, the opposite effect occurs. However, for very low Reynolds numbers, an incipient separation can occur on the first stage, which also influences the drag.
The role of Climate Change Levy schemes in aviation decarbonization by 2050
Authors: Arnaldo Valdés Rosa M , Gómez Comendador V Fernando
Published: January 2021

Aviation emissions from 2016 to 2050 could consume between 12% and 27% of the remaining carbon budget to keep global temperature rise below 1.5C above preindustrial levels. Consequently, aviation is being challenged to immediately start to reduce its in-sector emissions, then sharply reduce its CO2 emissions and fully decarbonize toward the second half of this century. Among the analyses carried out within the Horizon 2020 project PARE – Perspectives for Aeronautical Research in Europe, this paper tackles the potential role of Climate Change Levy Schemes in achieving the ambitious objective of aviation decarbonization by the year 2050.
Fast-acting shut-off and control ball valve application for control of gas flow rate to power plant boilers
Authors: Boldyrev I A , Kharitonov N V , Beokash A A , Menshikov P D
Published: January 2021

The work describes the design and algorithms for controlling the fast-acting shut-off and control ball valve calculation of the reliability of the natural gas flow control system for the power plant boiler. Its application makes it possible to improve the quality of fuel combustion control, as well as to reduce the quantity of shut-off and control valves of gas channel, which in turn also leads to improvement of reliability of the system as a whole.
The application of solar collectors in district heating systems: a case study in Krasnodar Krai
Authors: Buzoverov E A , Zhuk A Z
Published: January 2021

Though renewable energy sources are widely used around the world, the cost of “green” energy in most cases is still uncompetitive with the “traditional” one. This is most pronounced in countries and regions with a developed resource base, including Russia. However, renewable energy sources in some cases can be successfully implemented in district heating systems using natural gas. This paper reports on the effective use of simple design solar collectors in a gasified central heat supply system in the city of Gelendzhik, Krasnodar Krai, with the cost of heat generated does not exceed 0.01 USD/kWh. The conditions for reproduction of this project are defined following the results of its operation.
Hybrid heat supply systems using alternative and renewable energy sources
Authors: Gasho E G , Govorin A V , Kiseleva A I
Published: January 2021

The task of creating combined energy sources to cover diverse (thermal, electrical, etc.) loads is not entirely new. In the countries of the European Union (EU), hybrid energy systems for buildings, which combine heating, domestic hot water, as well as air conditioning, have long been widely used. The programs and normative documents adopted in these countries on improving the energy efficiency of heat supply and the use of renewable energy sources (RES) for this have contributed to the widespread introduction of hybrid systems and installations. The study analyzes the potential of non-traditional and renewable sources for energy supply systems of facilities. The world experience of introducing alternative energy sources is considered and the state and implementation of hybrid schemes in Russia is assessed. Hybrid power supply options for facilities for various purposes are proposed. The key problems of active use are examined and ways to solve them are proposed.
Distributed energy technology development
Authors: Losev O G , Melnik D A , Grigoriev A S
Published: January 2021

This article presents preliminary results of work on the development of advanced technologies for the development of distributed energy. In particular, the results of the first stage of creating control algorithms in a distributed power supply network and creating a simple scheme of interaction between two consumers with their own generation sources are shown. Calculations and testing of the selected principles of interaction in the MATLAB/Simulink program showed the efficiency of the decisions made.
Assessment of the intensity and flow of straight solar radiation falling onto the horizontal surface of a room
Authors: Yaremenko S A , Sheps R A , Mershchiev A A , Lobanov D V
Published: January 2021

The paper presents the results of experimental studies of straight solar radiation in the Central Chernozem region of Russia. The intensity and flow of straight solar radiation falling onto a horizontal surface of a room were evaluated. Measurements were made of the flow of straight solar radiation on a horizontal surface through a translucent structure. Experimental data were obtained using a high-class measuring device in the period from July 1 to August 1. The measurement results showed an intense wave-like change in the solar radiation flux over 8 hours. The paper describes a method for estimating the intensity and flow of straight solar radiation falling onto a horizontal surface of a room. This method of evaluating daytime radiation allows one to determine the density of the total and straight radiation flux. Using this estimate to calculate solar installations used in the Central Chernozem region, their efficiency will increase by 10%.
Improvements of choice of the water-chemical regime of reserve osmosis installation
Authors: Odoevtseva M V , Spiridonov D A
Published: January 2021

The effectiveness of monitoring the composition and intensity of deposits on reverse osmosis membranes is shown. The use of test installations of the NGO “NPK Mediana-Filter” speeds up and significantly reduces the labor intensity of monitoring deposits in the conditions of industrial operation of reverse osmosis installations. The effectiveness of determining the composition and intensity of deposits on the membrane surface using the energy dispersive analysis method was revealed. The effectiveness of commercial formulations for cleaning intensely contaminated membranes is not always sufficient. The use of ready-made solutions from various manufacturers excludes the possibility of a targeted selection of the concentration of a solvent to remove deposits from the membrane surface, provided that these solutions are safe for the operating parameters of the membranes. The monitoring results made it possible to implement a targeted choice of compositions of detergent mixtures, their combinations and the regime of their effect on deposits on membranes, provided that the pH of the solutions is stable throughout the entire cleaning time. Controlling the intensity of the formation of deposits according to the data of test installations will reduce the laboriousness of choosing the optimal water-chemical regime of an industrial reverse osmosis plant, which will reduce the rate of formation of deposits, increase the service life of membrane elements of an industrial water treatment plant with a consistently high quality of demineralized water.
Integrated information system of life cycle support of networks and electrical network equipment
Authors: Safronov V V , Barabanov V F , Nuzhnyy A M , Grebennikova N I
Published: January 2021

Taking into account the concept of seamless integration, this paper presents the structural and functional scheme of information systems’ integration. The proposed scheme is specified for typical life cycle control systems of networks and electrical network equipment in information systems, with the dominant use of domestic software products. In the proposed scheme, the functional features and limitations of the module for controlling and correcting drawings, as well as the module for digitizing archive documentation, are clarified to form a unified system for digital prototyping of products in the context of a continuous lifecycle. We present the developed structure of the integrated information system for lifecycle support of networks and electrical network equipment. An integrated information system for lifecycle support implies the implementation of software in the form of a series of specialized platform-independent software intermodular interfaces, which allows for quick configuration of the system for the existing industry and enterprise specifics.
Effectiveness of the joint scheme of steam-power and combined-cycle power units using the example of the Nevinnomyssk State Regional Thermal Power Plant
Authors: Shaposhnikov V V , Batko D N , Mihalko Ya O
Published: January 2021

We attempt to solve the problem of displacing high-temperature steam bleeding in a steam turbine plant at the first regenerative heater after intermediate overheating. This can be achieved when the thermal power plant contains heterogeneous equipment, in particular, a steam turbine and combined cycle power units. The authors proposed an energy-efficient scheme for the joint operation of steam turbine unit and steam-turbine part of a combined cycle plant with the displacement of high-temperature steam onto the high-pressure feed heater (HPFH 2) using the dry steam from the medium-pressure drum of the waste boiler in order to increase the upper limit of the power plant’s control range. For this research, Nevinnomyssk TPP was selected as one of the main energy facilities of the Unified Energy System of Southern Russia. We studied the joint operation of the steam turbine unit K-160-130 and the combined cycle plant CCP-410 manufactured by Siemens, Germany. We developed the methodology and calculated the energy efficiency of the new power plant operation scheme. According to the calculation results, the total increase in power amounted to 6.03 MW, while there was an increase in electrical gross efficiency by 0.64%. An assessment of the economic effect of the applied solution for the conditions of the Nevinnomyssk TPP demonstrated that the annual increase in net profit will amount to 14.47 million rubles, and the payback period of investments is 4.2 months.
Intensification of heat transfer in chaotic modes
Authors: Podvalny S L , Vasiljev E M
Published: January 2021

This paper presents the results of numerical modeling and comparative studies of the effectiveness of diffusion, convective, and turbulent heat transfer modes in a liquid layer. Here the heat transfer physical model was used which is typical for reactors with an internal energy source. Conditions for the continuity of the fluid flow and the equations of heat transfer, analytical and simulation models of these modes are obtained based on the Navier-Stokes equation. Quantitative characteristics have been found using the simulation model, confirming the expected efficiency indicators ratios of these processes in the course of heat transfer. Convective and turbulent heat transfer processes properties are analyzed as control objects basing on the Comsol Multiphysics modeling system. Recommendations have been obtained concerning the multi-alternative algorithms synthesis for automatic control of these processes. In particular, it is advisable to use the heat flux density as a control action, whereas the liquid particle velocity dispersion should be used as an adjustable value. Corresponding control system model demonstrated the efficiency of the proposed algorithms.
Autonomous spheroid formation by culture plate compartmentation
Authors: Fürsatz Marian , Gerges Peter , Wolbank Susanne , Nürnberger Sylvia
Published: January 2021

Scaffold-free 3D cell cultures (e.g. pellet cultures) are widely used in medical science, including cartilage regeneration. Their drawbacks are high time/reagent consumption and lack of early readout parameters. While optimisation was achieved by automation or simplified spheroid generation, most culture systems remain expensive or require tedious procedures. The aim of this study was to establish a system for resource efficient spheroid generation with additional early readout parameters. This was achieved by a new approach for spheroid generation via self-assembly from monolayer via compartmentation of cell culture surfaces utilising laser engraving (grid plates). The compartmentation triggered contraction and rolling up of the cell monolayer, finishing in condensation into a spheroid in human adipose-derived stem cell (ASC/TERT1) and human articular chondrocytes (hACs)-ASC/TERT1 co-cultures, when cultivated on grid plates under chondrogenic conditions. Plates with 1 and 3 mm grid size yielded stable diameters (about 140 µm and 300 µm, respectively). ASC/TERT1 spheroids fully formed within 3 weeks while co-cultures took 1–2 weeks, forming significantly faster with increasing hAC ratio (p < 0.05 and 0.01 for 1:1 and 1:4 ASC/TERT1:hAC ratio, respectively). Co-cultures showed slightly lower spheroid diameters, due to earlier spheroid formation and incomplete monolayer formation. However, this was associated with a more homogeneous matrix distribution in the co-culture. Both showed differentiation capacity comparable to standard pellet culture in (immune-)histochemistry and RT-qPCR. To assess usability for cartilage repair, spheroids were embedded into a hydrogel (fibrin), yielding cellular outgrowth and matrix deposition, which was especially pronounced in co-cultures. The herein presented novel cell culture system is not only a promising tool for autonomous spheroid generation with the potential of experimental and clinical application in tissue engineering, but also for the generation of ‘building blocks’ for subsequential biofabrication strategies such as bioprinting.
CentTracker: a trainable, machine-learning–based tool for large-scale analyses of Caenorhabditis elegans germline stem cell mitosis
Authors: Zellag Réda M. , Zhao Yifan , Poupart Vincent , Singh Ramya , Labbé Jean-Claude , Gerhold Abigail R.
Published: January 2021

We provide technical and analytical tools to facilitate large-scale intravital imaging studies of Caenorhabditis elegans germline stem cell (GSC) mitosis, which are expandable to other model systems. We assess multiple GSC mitotic features and find evidence for spatial clustering of divisions and a spindle orientation bias within the stem cell pool.
Neohesperidin alleviated pathological damage and immunological imbalance in rat myocardial ischemia-reperfusion injury via inactivation of JNK and NF-κB p65
Authors: Li Aihua , Zhang Xin , Luo Qiuping
Published: January 2021

Neohesperidin (NEO) exerts antiviral, antioxidant, anti-inflammation, and antitumor effects in some diseases. The purpose of this study was to investigate the effect and mechanism of NEO on myocardial ischemia-reperfusion (I/R) injury. Results indicated that NEO suppressed the levels of serum inflammatory cytokines, myocardial damage markers, and oxidative stress markers, and increased the levels of antioxidant in myocardial I/R rats. NEO also inhibited cell apoptosis. Besides, NEO also inhibited the phosphorylation of c-Jun N-terminal kinases (JNK) and nuclear factor kappa B (NF-κB) p65. Furthermore, the protective effects of NEO on myocardial tissue damage, inflammatory cytokines, myocardial injury markers, oxidative stress markers, cell apoptosis, spleen, thymus and liver indices, and phagocytic indices were reversed by JNK activator and NF-κB activator, respectively. In conclusion, NEO alleviates myocardial damage, oxidative stress, cell apoptosis, and immunological imbalance in I/R injury via the inactivation of JNK and NF-κB, making NEO a potential agent for myocardial I/R therapy.
Functional alterations caused by mutations reflect evolutionary trends of SARS-CoV-2
Authors: Cheng Liang , Han Xudong , Zhu Zijun , Qi Changlu , Wang Ping , Zhang Xue
Published: January 2021

Since the first report of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019, the COVID-19 pandemic has spread rapidly worldwide. Due to the limited virus strains, few key mutations that would be very important with the evolutionary trends of virus genome were observed in early studies. Here, we downloaded 1809 sequence data of SARS-CoV-2 strains from GISAID before April 2020 to identify mutations and functional alterations caused by these mutations. Totally, we identified 1017 nonsynonymous and 512 synonymous mutations with alignment to reference genome NC_045512, none of which were observed in the receptor-binding domain (RBD) of the spike protein. On average, each of the strains could have about 1.75 new mutations each month. The current mutations may have few impacts on antibodies. Although it shows the purifying selection in whole-genome, ORF3a, ORF8 and ORF10 were under positive selection. Only 36 mutations occurred in 1% and more virus strains were further analyzed to reveal linkage disequilibrium (LD) variants and dominant mutations. As a result, we observed five dominant mutations involving three nonsynonymous mutations C28144T, C14408T and A23403G and two synonymous mutations T8782C, and C3037T. These five mutations occurred in almost all strains in April 2020. Besides, we also observed two potential dominant nonsynonymous mutations C1059T and G25563T, which occurred in most of the strains in April 2020. Further functional analysis shows that these mutations decreased protein stability largely, which could lead to a significant reduction of virus virulence. In addition, the A23403G mutation increases the spike-ACE2 interaction and finally leads to the enhancement of its infectivity. All of these proved that the evolution of SARS-CoV-2 is toward the enhancement of infectivity and reduction of virulence.
Lysosome activation in peripheral blood mononuclear cells and prognostic significance of circulating LC3B in COVID-19
Authors: Fang Shisong , Zhang Lin , Liu Yingzhi , Xu Wenye , Wu Weihua , Huang Ziheng , Wang Xin , Liu Hui , Sun Ying , Zhang Renli , Peng Bo , Liu Xiaodong , Sun Xiao , Yu Jun , Chan Francis Ka Leung , Ng Siew Chien , Wong Sunny Hei , Wang Maggie Hai Tian , Gin Tony , Joynt Gavin Matthew , Hui David Shu Cheong , Feng Tiejian , Wu William Ka Kei , Chan Matthew Tak Vai , Zou Xuan , Xia Junjie
Published: January 2021

Coronavirus disease 2019 (COVID-19) has spread rapidly worldwide, causing significant mortality. There is a mechanistic relationship between intracellular coronavirus replication and deregulated autophagosome–lysosome system. We performed transcriptome analysis of peripheral blood mononuclear cells (PBMCs) from COVID-19 patients and identified the aberrant upregulation of genes in the lysosome pathway. We further determined the capability of two circulating markers, namely microtubule-associated proteins 1A/1B light chain 3B (LC3B) and (p62/SQSTM1) p62, both of which depend on lysosome for degradation, in predicting the emergence of moderate-to-severe disease in COVID-19 patients requiring hospitalization for supplemental oxygen therapy. Logistic regression analyses showed that LC3B was associated with moderate-to-severe COVID-19, independent of age, sex and clinical risk score. A decrease in LC3B concentration <5.5 ng/ml increased the risk of oxygen and ventilatory requirement (adjusted odds ratio: 4.6; 95% CI: 1.1–22.0; P = 0.04). Serum concentrations of p62 in the moderate-to-severe group were significantly lower in patients aged 50 or below. In conclusion, lysosome function is deregulated in PBMCs isolated from COVID-19 patients, and the related biomarker LC3B may serve as a novel tool for stratifying patients with moderate-to-severe COVID-19 from those with asymptomatic or mild disease. COVID-19 patients with a decrease in LC3B concentration <5.5 ng/ml will require early hospital admission for supplemental oxygen therapy and other respiratory support.
Comparison of the binding characteristics of SARS-CoV and SARS-CoV-2 RBDs to ACE2 at different temperatures by MD simulations
Authors: Yan Fang-Fang , Gao Feng
Published: January 2021

Temperature plays a significant role in the survival and transmission of SARS-CoV (severe acute respiratory syndrome coronavirus) and SARS-CoV-2. To reveal the binding differences of SARS-CoV and SARS-CoV-2 receptor-binding domains (RBDs) to angiotensin-converting enzyme 2 (ACE2) at different temperatures at atomic level, 20 molecular dynamics simulations were carried out for SARS-CoV and SARS-CoV-2 RBD–ACE2 complexes at five selected temperatures, i.e. 200, 250, 273, 300 and 350 K. The analyses on structural flexibility and conformational distribution indicated that the structure of the SARS-CoV-2 RBD was more stable than that of the SARS-CoV RBD at all investigated temperatures. Then, molecular mechanics Poisson–Boltzmann surface area and solvated interaction energy approaches were combined to estimate the differences in binding affinity of SARS-CoV and SARS-CoV-2 RBDs to ACE2; it is found that the binding ability of ACE2 to the SARS-CoV-2 RBD was stronger than that to the SARS-CoV RBD at five temperatures, and the main reason for promoting such binding differences is electrostatic and polar interactions between RBDs and ACE2. Finally, the hotspot residues facilitating the binding of SARS-CoV and SARS-CoV-2 RBDs to ACE2, the key differential residues contributing to the difference in binding and the interaction mechanism of differential residues that exist at all investigated temperatures were analyzed and compared in depth. The current work would provide a molecular basis for better understanding of the high infectiousness of SARS-CoV-2 and offer better theoretical guidance for the design of inhibitors targeting infectious diseases caused by SARS-CoV-2.