bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elastic-plastic time-history analysis of steel-tube stiff-frame arch bridge without inner filling concrete
Authors: Zhang Ben , Li Li , Su Wenming 
Published: February 2021

Abstract
Based on a case study of a typical arch bridge with hollow steel tube and stiffness frame located in the high intensity region of western China, this paper adopts the onlinear time- history method to analyze the structural response of the overall bridge elastic-plastic model under seismic action. Under the force of Wolong wave in Wenchuan Earthquake, the main load-bearing members of the structure have a good seismic performance. Only part of the columns on the main arch ring enter the plastic hinge state for energy dissipation, and the lower columns have a more obvious energy dissipation effect than the higher ones. The result indicates that the design idea of structure which is similar to that of strong column and weak beam in ductility design, has the characteristics of “strong arch and weak beam” and can therefore improve the ability of structure to resist collapse under earthquake action.
Time history analysis method for the combined action of extreme fluctuating wind and wave on the maximum double cantilever structure of rigid frame bridge considering the influence of flow velocity
Authors: Chen Yiqian , Peng Wei 
Published: February 2021

Abstract
Taking the maximum double cantilever structure of rigid frame bridge in construction period as the research object, the structural dynamic response analysis under the combined action of extreme wind and wave is carried out, considering the influence of flow velocity. An analysis method of short-term pulsation effect of a structure is proposed considering the influence of various adverse factors under extreme wind and wave conditions, which provides a reference for structural safety assessment under extreme conditions; The dynamic response results of the maximum double cantilever structure of rigid frame bridge show that the wave-flow effect under extreme wind and wave conditions will increase the structural response during the construction period, resulting in adverse effects.
Cause analysis and countermeasure of blockage in urea pyrolysis denitration system of coal-fired power plant
Authors: Yao Yongqi , Gui Sha , Yang Jiaxian , Wei Jianbo , Zhang Wen , Li Peipei , Xue Fangming , Su Jingcheng , Liu Xiuru 
Published: February 2021

Abstract
Due to the safety and convenience storage of raw materials and the maturing technology, the method of urea pyrolysis for ammonia has been widely used in the selective catalytic reduction (SCR) denitration technology of thermal power plants. However, crystallization and blockage phenomennons occured frequently, seriously disrupting the normal operation of SCR denitrification systems. In order to analysis the reasons of crystallization plugging in urea pyrolysis process, This paper collects and analyzes the scaling samples from pyrolysis furnace and spraying ammonia pipe to identify scaling substances, analyzes the reasons of urea crystallization, puts forward the improvement measures so as to guarantee the safety and steady operation of SCR-DeNOx system.
An investigation of pattern design of draped necklines
Authors: Kazlacheva Zlatina , Kosinkova-Stoeva Angelina 
Published: February 2021

Abstract
The paper presents an investigation of pattern design of this type of drapery with main idea easy and correct constructing. The aim of the work is development of a facilitating and accurate system of pattern design on the base of studying different constructional systems and finding a way of correct measurement with the help of approximation of the draped neckline with a parabola and a dependence, obtained by a multiple linear regression. The results of the investigation lead to easy and correct geometrical way of pattern design and easy and correct measurements of the draped necklines in ladies’ clothing. The dependence of measurements can be use not only with presented pattern design system but with every other way for constructing draped neck opening. The measures on the made prototypes show that there isn’t any additional length to the draped neckline as result of the skew direction (in the more times) and the weight of the fabric in the garments made from woven fabrics. But there is additional length of the draped neckline in the garments made from knitted fabrics, result of the stretchability in all directions. In the garments from woven fabrics stretchability in skew direction is balanced by lack of it in both basic directions, and by this reason the stretchability forms the drapery but does not add length to the draped neckline. Therefore, the obtained dependence of measurement of the draped neckline is suitable for garments from woven fabrics and a base for the future study about draped necklines in clothes from stretched materials.
Analysis of non-conventional (dry) sizing methods
Authors: Blagova E , Balabanova D , Paleva-Kadiyska B 
Published: February 2021

Abstract
The method of “dry” sizing has long been known, but has not received widespread industrial application due to the high cost of the sizing ingredients. A classification of the variants of this method is presented and the differences, advantages and disadvantages of each of them are revealed. An experiment was performed for sizing of threads by two of the variants of the method, determining some of their main characteristics and comparing them with those of threads sizing in the classical way.
Determination of limiting fibers blend irregularity
Authors: Ryklin D B , Navumenka A M 
Published: February 2021

Abstract
Aim of the research is obtaining formulae for determination of limiting blending irregularity of fiber assemblies on the base of simulation. Obtained formulae show the influence of the fibers properties and their percentage on blends irregularity and can be used for evaluating blending process efficiency. Comparison of actual blend irregularity and limiting values allows to asses potential opportunities of the process improving. It was experimentally proven that influence of fiber blends parameters on actual blend irregularity corresponded to obtained formulae.
Research of influence of blended yarn structure including stainless steel fibers on its properties
Authors: Medvetski S S , Ryklin D B , Davidziuk V V 
Published: February 2021

Abstract
Analysis of changes in the electrical resistance of different blended of yarns containing stainless steel fibers Bekinox® before and after plying very important for develop antistatic textile materials. Hypothesis was suggested that the plying of two strands leads to yarn conductivity increasing because of rise of the contacts number between stainless steel fibers on their surfaces. Producing of ring-spun 20 tex yarns and 2-ply yarns of linear density 20 tex × 2 were investigated. It is found that that the addition of 10 % stainless fibers into the yarn reduces its electrical resistance in 105 – 106 times. Experimental results show that after plying the yarn conductivity increases. However, this degree of this effect depends on the type of non-conductive fiber (cotton or polyester). Based on the yarn structure simulation it is proven that plying of two strands leads to yarn conductivity increasing because of rise of the contacts number between stainless steel fibers on their surfaces.
Constructing a hyperoperation sequence-pisa hyperoperations
Authors: Andonov A P 
Published: February 2021

Abstract
In the context of other hyperoperation sequences, a new sequence of operations is constructed. A review of its properties reveals dependences between pairs of numbers, and so the sibling numbers are established. Two theorems are proven and the connection to small base tetration is revealed. The problem of extending the sequence to real levels is considered and linked to tetration height extension. The pisa operations can be a useful tool for exploring tetration and large numbers.
Vegetation in Bulgaria according to data from satellite observations and NASA models
Authors: Todorova Mima , Grozeva Neli , Takuchev Nikolay P , Ivanova Dafinka , Kuzmova Kalinka , Kazandjiev Valentin , Georgieva Veska , Velichkova Radomira , Boneva Vanya 
Published: February 2021

Abstract

Introduction. The condition of the vegetation cover can be traced from Space. Aim of the research. To assess the condition of the vegetation cover in Bulgaria during the last twenty years – its distribution over the country, its change in connection with the typical climatic changes, its seasonal change. Material and methods. The vegetation index NDVI according to NASA data was used to analyze the condition of the vegetation cover in Bulgaria for the years 2000-2020. The methods used were: seasonal data decomposition, t-test, GIS methods for spatial representation of data, Fourier analysis. Conclusions. 1. During the summer months the vegetation in the eastern parts of the territory of Bulgaria is noticeably weaker than in the western parts. The influencing factors-drought and frequent fires are probably related to global warming. 2. For the territory of Bulgaria there is a seasonal rotation of the horizontal gradient of the vegetation index in a counterclockwise direction-from east to west in summer, from northeast to southwest in autumn and from north to south in winter. 3. There is a winter increase in vegetation for Northern Bulgaria and to the greatest extent for Northeastern Bulgaria, as well as for Southwestern Bulgaria. Together with the decreasing snow cover, the winter vegetation contributes to the drought in the eastern parts of the country.
Adaptive technologies for training of specialists
Authors: Yelnykova H , Ryabova Z 
Published: February 2021

Abstract
The article is devoted to the organization of the educational process of specialists’ training by means of the adaptive teaching technologies. We have described the philosophy of instability that underlies such technologies: from chaos to self-organization. By showcasing the concepts of adaptation and adaptability, we define the content and stages of adaptive technology. The article presents the results of monitoring the trends of respondents’ awareness of the technologies of using the Bloom’s taxonomy in professional activities, which are necessary for the formation of the educational program of specialists’ training. Considering that the Bloom’s taxonomy strengthens the learning processes of applicants.
Application of a method for calculating the sizes of perspective objects
Authors: Bankova A I 
Published: February 2021

Abstract
Determining the parameters of perspective images of different objects is a complex problem. Graphic, graphoanalytical and analytical methods are used to solve such problems. Graphic methods are not accurate enough for complex objects compared to analytical methods, which although difficult to apply, are proved to be the most accurate ones. Graphoanalytical methods according to are considered the most appropriate in terms of accuracy and complexity of application. The purpose of this paper is to propose a graphoanalytic method for determining the parameters of perspective images of a parallelepiped. The coordinates of the points which are the vertices of the perspective image and the equations of the lines on which the edges of the perspective image lie are determined both by applying the knowledge of constructing a perspective image and that of analytical geometry.
Change from one Method to Another for Processing by Cutting a Complex Rotary Surfaces
Authors: Vasileva D , Lefterov E 
Published: February 2021

Abstract
Many authors involved in the processing of materials by cutting make different definitions for complex rotary surface. They are reduced to the definition published in [1]: A complex rotating surface is called one that is composed as a combination of two or more of the following elementary surfaces - conical, frontal, cylindrical, curvilinear. The methods and devices used in machining parts that are constrained by complex rotary surfaces depend on following several factors: type of production (single, serial, mass); type of available equipment and shape accuracy and surface quality.
Potential for the regional energy supply system optimization through recycling waste into energy
Authors: Tulegenova A A , Andreenko T I , Rafikova Yu Yu 
Published: February 2021

Abstract
The use of renewable energy sources is becoming a general trend for optimizing energy supply and achieving low-carbon development goals in various regions of the world. In Russia, in connection with the introduction and implementation of government support measures for solar, wind, bioenergy, starting in 2013, a large-scale introduction of energy-generating facilities began. This factor, as well as the need to solve the problem of recycling waste from the municipal sector, agriculture and forestry, makes it necessary to use local renewable energy resources, including waste. This approach helps to optimize the regional energy system, even if they are grid connected. The paper discusses the methods and potential for optimizing energy supply in the regions of southern Russia, which has a high population density, a significant deficit in energy balance, and problems in the field of solid waste processing. The basis for this work is the use of municipal sector waste as an energy resource, with an assessment of the economic and environmental efficiency of this process. The use of geoinformation technologies provides a spatial analysis of the resource potential, a comparative analysis of the distribution of energy production and consumption within the region, as well as helps to assess the availability of territories for the optimal placement of solid municipal waste processing facilities.
Modal analysis of the nozzle guide vane in low pressure turbine system of aircraft engine
Authors: Robak R , Szczepanik M 
Published: February 2021

Abstract
The aim of the article is to present modal analysis of nozzle guide vane in low pressure turbine system of aircraft engine. Comparison of results obtained by means of finite element analysis with results of experimental one in terms of frequencies and modal forms are presented. Additionally, the article presents consistent results which will be used in further analyses and researches related to the optimization of dynamic characteristics with application of artificial intelligence.
Drivability improvements obtained using a mild hybrid electrical system on a vehicle equipped with a manual gearbox
Authors: Saragea Ștefan , Frățilă Gheorghe , Badea Gabriel 
Published: February 2021

Abstract
In order to fulfil the latest and future emission standards, all vehicles will need to be equipped with hybrid powertrains or advanced depollution systems. For low cost and entry level range of vehicles, in order to keep the production costs low, the simplest choice of hybridization is the mild-hybrid system with integrated starter-generator (ISG). This paper contains a model of a mild-hybrid electric vehicle equipped with a manual gearbox with focus on the drivability performance of the powertrain. The goal of this paper is to find out the drivability performances of a hybrid vehicle by simulation and to show the improvements compared to a similar vehicle equipped with a conventional powertrain.
Aerodynamic shape optimization of racing car front wing
Authors: Kalinowski M , Szczepanik M 
Published: February 2021

Abstract
Nowadays, the automotive industry is one of the largest areas of CFD (Computational Fluid Dynamics) simulation applications. The big challenge that engineers dealing with CFD simulations in this industry have to face is shape optimization, which is often very time-consuming and requires a lot of iterations. To reduce the time needed to achieve an optimal shape and make the design process more efficient, more and more CFD analysts are turning to Adjoint Solver (AS) formulas, a new methodology used for optimization in the automotive as well as railway industry. The AS method calculates gradients (directions, quantities) directly by solving conjugate equations, which makes them independent of design variables. The article concerns optimization the shape of the front wing of the racing car in order to obtain the highest possible downforce-to-drag ratio. At the beginning, 2D shape optimization of the front wing was performed. The next stage of work was the preparation of a CAD (3D) model that took into account the change in the shape of the wing, obtained during the optimization process, and then performing a flow analysis for it.
Distribution of resources for equipping handling fronts in rail consolidation terminals
Authors: Stere A Ș , Roman E A 
Published: February 2021

Abstract
An indispensable factor of the socio-economic life, the transports realize the connection between the economic zones, which facilitates the attraction of all the companies to the economic circuit, to the capitalization of the available resources and to their overall development. The influence of transport volumes is clearly manifested on the capacity of the terminals, the number of means of transport necessary to satisfy the demand, the degree of their use, the economy of the goods handling installations, the capacity of the handling fronts and labour productivity. Therefore, it is of a great importance to design the constructions and equipments of the terminals according to a criteria based on the optimal structure of the technical endowment subject to variations in the volume of transport activities. The present paper aims to present a theoretical framework for the distribution of resources for equipping handling fronts of the rail terminals. A mathematical model and a algorithm based on the projected gradient method are developed to solve this problem.
Software application for optimizing raw material costs, including materials recovered from batteries and accumulators
Authors: Florea B , Marcu D , Ioana A , Semenescu A , Solea R , Iacob G , Niculescu F 
Published: February 2021

Abstract
In this article we aim to create a software application aimed at highlighting the importance of the technical and economic estimate in making the bushings. This software was created as a web platform, available at: https://www.bucsa-sim.com, in order to maximize the accessibility, speed and efficiency of the complex process that underlies the construction of parts, in our case, bushings. The idea of developing this software started from the necessity generated by the fact that currently there is only one website on the Romanian market available at: https://bucsebronz.ro/calculator-piese/, which does not allow users to calculate the technical-economic estimate in real time, but only to send a simple form to the company. The use of this application is part of the new concept of Industrialization 4.0 because it allows operation in the cloud with immediate access to the display of the price of a bushing made of elements recovered from waste. Taking into consideration that materials such as copper and lead can come from recycling of batteries and accumulators, this application contributes to a better integration of the processing of these materials in the priciples or the circular economy.
Forecasting technique of radio information system characteristics for optimal technical condition of the space control system components
Authors: Korneev N V , Merkulov V D 
Published: February 2021

Abstract
The paper proposes a forecasting technique of radio information system characteristics for optimal technical condition of space control system components, using a recurrent neural network and information tools from an early-warning radar stations group and Russian Aerospace Forces optical-electronic stations when determining the optimal technical condition of the Space Monitoring System (SMS) components. Analyzing values of time series by a recurrent neural network LSTM-based model with various parameters, we propose an algorithm for solving problem of forecasting characteristics of a radio information complex. The network architecture is a two-layer network with one layer of LSTM cells and one fully connected layer. There are results of experimental forecasting by pre-training the recurrent neural network (RNN) model sampling 1080 normalized measurements of a conditional sensor of 30 minutes apart. The training sample is made of conditional sensor normalized values for 9 hours continuous operation. The algorithm for the model training and creation is implemented in Python language using open source library TensorFlow. Experiments were performed with different values of the forecast horizon and the length of the input sequence of time series values. We obtained: the total average error for each combination of parameters, the dependence of the average forecast error on the used parameters and the dependence of the average (for all forecast values) forecast error on the period of the analyzed sensor values.
Verification of mathematical models to optimize the composition of radio-absorbing polymer composite materials
Authors: Markov A V , Oreshina O A 
Published: February 2021

Abstract
At present, radio-absorbing dispersed-filled polymer composite materials have become widespread in aviation technology. These materials are used to protect electronic units of on-Board equipment from electromagnetic radiation. The article considers the need to develop mathematical models of the dependence of the composition of radio-absorbing polymer composite materials on their physical and mechanical properties. The article deals with the optimization of a group of physical and mechanical properties described by mathematical models in order to obtain the optimal composition of a radio-absorbing dispersed-filled polymer composite material based on heat-resistant low-molecular synthetic rubber with the addition of untreated ferric oxide as a filler. The research method is optimization by the method of successive concessions. Computer experiments were carried out to optimize the composition of materials. The performed calculations were checked by experimental data, the adequacy of the obtained models was checked.
Simulation model for predicting reciprocating internal combustion engine wear
Authors: Malozemov A A , Kozminykh D V , Malozemov G A , Shavlov A V 
Published: February 2021

Abstract
The article presents the results of software development, using the Modelica language, designed to create and use simulation models as part of reciprocating internal combustion engines digital twins. The software was created on the basis of component, system and declarative approaches, the theory of a casual bond graphs. The software includes submodels for determining the main engine parts wear rate and allows to predict engine parts life time, to simulate normal and accelerated engine reliability and durability tests. In the course of the study, the well-known model for determining mechanical frictional losses SLM (Shayler, Leong, Murphy, 2005) was adapted to calculate the relative change in the wear rate of engine parts. Universal equations are obtained to determine the friction forces as applied to rotationally and reciprocally moving engine parts. A method is proposed for calculating the relative change in the wear rate of parts and the time of failure due to wear, taking into account the physical properties (hardness), geometric dimensions and the speed of the relative movement of parts in the conjunction.