bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-consistent modeling of beam-plasma interaction in the charge breeding optimization process
Authors: Galatà A. , Mascali D. , Gallo C. S. , Torrisi G.
Published: January 2020

The slowing down and capture by a plasma of externally injected 1+ ions, as a consequence of very frequent elastic Coulomb collisions, is the main mechanism involved in the charge breeding process based on electron cyclotron resonance ion sources. The Istituto Nazionale di Fisica Nucleare ion source group has been undertaking an intense activity on numerical simulations of the beam-plasma interaction, developing a code that has been proven to be very effective in reproducing several experimental results of charge breeding of light and heavy ions. This contribution will present the progress made in the development of the numerical code, focusing the attention on the latest simulations of charge breeding of Rb1+ ions employing a self-consistent plasma target model. The effect of the real plasmoid/halo structure on the capture process will be underlined, as well as the influence of different plasma excitation frequencies.
Host protein glycosylation in nucleic acid vaccines as a potential hurdle in vaccine design for nonviral pathogens
Authors: Ozdilek Ahmet , Paschall Amy V. , Dookwah Michelle , Tiemeyer Michael , Avci Fikri Y.
Published: January 2020

Nucleic acid vaccines introduce the genetic materials encoding antigenic proteins into host cells. If these proteins are directed into the secretory pathway with a signal/leader sequence, they will be exposed to the host’s glycosylation machinery, and, if their amino acid sequences contain consensus sequons for N-linked glycosylation, they may become glycosylated. The presence of host glycans on the proteins of microbial origin may prevent a strong protective immune response either through hindering access to key epitopes by lymphocytes or through altering immune responses by binding to immunoregulatory glycan-binding receptors on immune cells. Ag85A expressed by
Mycobacterium tuberculosis
(
Mtb
) is a bacterial surface protein that is commonly used in nucleic acid vaccines in multiple clinical trials. Here we show that, when Ag85A is expressed in mammalian cells, it is glycosylated, does not induce a strong humoral immune response in mice, and does not activate Ag85A-specific lymphocytes as highly as Ag85A natively expressed by the bacterium. Our study indicates that host glycosylation of the vaccine target can impede its antigenicity and immunogenicity. Glycosylation of the antigenic protein targets therefore must be carefully evaluated in designing nucleic acid vaccines.
Activation by substoichiometric inhibition
Authors: Merdanovic Melisa , Burston Steven G. , Schmitz Anna Laura , Köcher Steffen , Knapp Stefan , Clausen Tim , Kaiser Markus , Huber Robert , Ehrmann Michael
Published: January 2020

Significance

Small-molecule inhibitors of enzymes are commonly derived from native ligands and represent invaluable and extensively applied tools in chemical biology. In addition to the well-known issue of selectivity, paradoxical curiosities were described over decades that have wide implications in drug discovery and treatment. Of particular interest are observations where low concentrations of inhibitors may activate their targets instead of causing partial inhibition. Our conceptual analysis explains the general phenomenon of “activation by inhibition” as a ligand-induced transition between the T state and the R state in the classic Monod–Wyman–Changeux model of activation, in which the inhibitory ligand acts as an activator.
Phenotypic analysis of extracellular vesicles: a review on the applications of fluorescence
Authors: Panagopoulou Maria S. , Wark Alastair W. , Birch David J S , Gregory Christopher D.
Published: January 2020

Extracellular vesicles (EVs) have numerous potential applications in the field of healthcare and diagnostics, and research into their biological functions is rapidly increasing. Mainly because of their small size and heterogeneity, there are significant challenges associated with their analysis and despite overt evidence of the potential of EVs in clinical diagnostic practice, guidelines for analytical procedures have not yet been properly established. Here, we present an overview of the main methods for studying the properties of EVs based on the principles of fluorescence. Setting aside the isolation, purification and physicochemical characterization strategies which answer questions about the size, surface charge and stability of EVs (reviewed elsewhere), we focus on available optical tools that enable the direct analysis of phenotype and mechanisms of interaction with tissues. In brief, the topics on which we elaborate range from the most popular approaches such as nanoparticle tracking analysis and flow cytometry, to less commonly used techniques such as fluorescence depolarization and microarrays as well as emerging areas such as fast fluorescence lifetime imaging microscopy (FLIM). We highlight that understanding the strengths and limitations of each method is essential for choosing the most appropriate combination of analytical tools. Finally, future directions of this rapidly developing area of medical diagnostics are discussed.
Interferometry for full temporal reconstruction of laser-plasma accelerator-based seeded free electron lasers
Authors: Labat M , Bielawski S , Loulergue A , Corde S , Couprie M-E , Roussel E
Published: January 2020

The spectacular development of Laser-Plasma Accelerators (LPA) appears very promising for a free electron laser application. The handling of the inherent properties of those LPA beams already allowed controlled production of LPA–based spontaneous undulator radiation. Stepping further, we here unveil that the forthcoming LPA–based seeded FELs will present distinctive spatio-spectral distributions. Relying on numerical simulations and simple analytical models, we show how those interferometric patterns can be exploited to retrieve, in single-shot, the spectro-temporal content and source point properties of the FEL pulses.
Shapes of Fe nanocrystals encapsulated at the graphite surface
Authors: Lii-Rosales Ann , Han Yong , Julien Scott E , Pierre-Louis Olivier , Jing Dapeng , Wan Kai-Tak , Tringides Michael C , Evans James W , Thiel Patricia A
Published: January 2020

We describe and analyze in detail the shapes of Fe islands encapsulated under the top graphene layers in graphite. Shapes are interrogated using scanning tunneling microscopy. The main outputs of the shape analysis are the slope of the graphene membrane around the perimeter of the island, and the aspect ratio of the central metal cluster. Modeling primarily uses a continuum elasticity (CE) model. As input to the CE model, we use density functional theory to calculate the surface energy of Fe, and the adhesion energies between Fe and graphene or graphite. We use the shaft-loaded blister test (SLBT) model to provide independent stretching and bending strain energies in the graphene membrane. We also introduce a model for the elastic strain in which stretching and bending are treated simultaneously. Measured side slopes agree very well with the CE model, both qualitatively and quantitatively. The fit is optimal for a graphene membrane consisting of 2–3 graphene monolayers, in agreement with experiment. Analysis of contributions to total energy shows that the side slope depends only on the properties of graphene/graphite. This reflects delamination of the graphene membrane from the underlying graphite, caused by upward pressure from the growing metal cluster. This insight leads us to evaluate the delamination geometry in the context of two related, classic models that give analytic results for the slope of a delaminated membrane. One of these, the point-loaded circular blister test model, reasonably predicts the delamination geometry at the edge of an Fe island. The aspect ratio also agrees well with the CE model in the limit of large island size, but not for small islands. Previously, we had speculated that this discrepancy was due to lack of coupling between bending and stretching in the SLBT model, but the new modeling shows that this explanation is not viable.
A mass-conserved multiphase lattice Boltzmann method based on high-order difference*
Authors: Qin Zhang-Rong , Chen Yan-Yan , Ling Feng-Ru , Meng Ling-Juan , Zhang Chao-Ying
Published: January 2020

The Z–S–C multiphase lattice Boltzmann model [Zheng, Shu, and Chew (ZSC), J. Comput. Phys.
218, 353 (2006)] is favored due to its good stability, high efficiency, and large density ratio. However, in terms of mass conservation, this model is not satisfactory during the simulation computations. In this paper, a mass correction is introduced into the ZSC model to make up the mass leakage, while a high-order difference is used to calculate the gradient of the order parameter to improve the accuracy. To verify the improved model, several three-dimensional multiphase flow simulations are carried out, including a bubble in a stationary flow, the merging of two bubbles, and the bubble rising under buoyancy. The numerical simulations show that the results from the present model are in good agreement with those from previous experiments and simulations. The present model not only retains the good properties of the original ZSC model, but also achieves the mass conservation and higher accuracy.
Review on electrode-level fracture in lithium-ion batteries*
Authors: Lu Bo , Ning Chengqiang , Shi Dingxin , Zhao Yanfei , Zhang Junqian
Published: January 2020

Fracture occurred in electrodes of the lithium-ion battery compromises the integrity of the electrode structure and would exert bad influence on the cell performance and cell safety. Mechanisms of the electrode-level fracture and how this fracture would affect the electrochemical performance of the battery are of great importance for comprehending and preventing its occurrence. Fracture occurring at the electrode level is complex, since it may involve fractures in or between different components of the electrode. In this review, three typical types of electrode-level fractures are discussed: the fracture of the active layer, the interfacial delamination, and the fracture of metallic foils (including the current collector and the lithium metal electrode). The crack in the active layer can serve as an effective indicator of degradation of the electrochemical performance. Interfacial delamination usually follows the fracture of the active layer and is detrimental to the cell capacity. Fracture of the current collector impacts cell safety directly. Experimental methods and modeling results of these three types of fractures are concluded. Reasonable explanations on how these electrode-level fractures affect the electrochemical performance are sorted out. Challenges and unsettled issues of investigating these fracture problems are brought up. It is noted that the state-of-the-art studies included in this review mainly focus on experimental observations and theoretical modeling of the typical mechanical damages. However, quantitative investigations on the relationship between the electrochemical performance and the electrode-level fracture are insufficient. To further understand fractures in a multi-scale and multi-physical way, advancing development of the cross discipline between mechanics and electrochemistry is badly needed.
Deformation of intermediate zones of two-layers elements of reinforced concrete structures
Authors: Fedorova N V , Gubanova M S , Savin S Yu
Published: January 2020

Analytical dependences are constructed for a characteristic reinforced concrete element simulating inter-medium contact zones with simultaneously occurring processes of changing the long-term strength of concrete in time, taking into account the aging process of concrete and the process of neutralizing concrete with an aggressive environment. The proposed version of the calculation model of the long-term deformation of a corrosion-damaged composite reinforced concrete element in the zone of contact of two concretes makes it possible to study the deformed state of such structures in a plane stress state.
Possibilities and limitations of high-strength lightweight fiber-reinforced concrete structures
Authors: Duong T Q , Vu N T , Inozemtcev A S , Korolev E V
Published: January 2020

The paper shows the study of the possibilities, limitations in the design of structures made of high-strength lightweight fiber-reinforced concrete and its use in the construction of a high-rise building using the LIRA SAPR software package. The calculations of the finite-element spatial model show that compared to heavy concrete, using high-strength lightweight fiber-reinforced concrete in the multi-storey buildings construction provides a large number of advantages, such as: reducing deflection of the building from its own weight up to 44.0%, from effect to wind loads - by 2,4 … 2.6% with a decrease in the period of the first 3 vibrations of the building structure by 11.3%; an increase in the number of storeys to 7 floors without changing foundation bearing capacity; increasing specific usable area per 1 m2 of building land by 26.6%; reducing consumption of materials for the foundation while maintaining the number of storeys of the building or the possibility of construction in weak soils. At the same time, the technology of high-strength lightweight fiber-reinforced concrete, combining low average density and high strength, is associated with an increase in the cost of the material, therefore, the existing limitations can be identified: the dependence of economic efficiency on the structural features of a particular building, construction conditions and local resources used for concrete production.
Indicator system for monitoring the development of urban bicycle transport infrastructure
Authors: Kireeva N , Zavialov D , Saginova O , Zavyalova N
Published: January 2020

Based on surveys of bicyclists and the study of foreign practice with regard to monitoring the development of bicycle transport infrastructure, scientists from Plekhanov Russian University of Economics have offered a flexible system of indicators to assess and plan the development of the bicycle transport infrastructure for the city of Moscow.
Analysis of the structures in water treatment and sanitation facilities for their strengthening
Authors: Rimshin V I , Kuzina E S , Shubin I L
Published: January 2020

The destruction of water treatment and wastewater treatment plants occurs under a number of factors, which include: precipitation affects the external parts of structures, moisture penetrates into the body of the structure and beyond it, weather conditions: variable temperatures, weathering, biological effects, ultraviolet radiation lead to destruction any building material. The main reasons of destruction and damage to building structures in various water treatment and wastewater disposal facilities are discussed, the most effective ways for eliminating these damages are provided in this article. The calculation substantiation of the supporting structures reinforcement namely reinforced concrete slabs in water treatment structures is carried out.
Study of impact sheet pile and Franki NG pile driving on weir construction
Authors: Wyjadłowski M , Sawicki E
Published: January 2020

The proper quality and the safe execution of geotechnical works imposes the necessity of monitoring techniques to prevent the threats arising from the vibrations. This work presents authors experience gained during sheet piling and Franki pile driving in time of construction of water power plant. Dynamic impact of foundation works can be perceptible by humans and can affect structures and technical devices. The immediate reason for the dynamic analysis was the occurrence of clearly perceivable vibration of the weir. The measurements were performed during sheet wall installation and Franki pile driving at various measuring points. Wave parameter measurements and recording of shocks and vibrations in the close vicinity of the construction site were juxtaposed for different installation phases and measuring points. A comparison of the two technologies shows that the largest vibrations occur during formation of the cast-in-situ (over)expanded Franki pile base. Sheet pile wall installation supported by additional processes such as pre-boring turned out to be as less harmful.
Development of the methodology of calendar planning in the system of organizational and technological preparation of capital repair of multi-apartment residential houses
Authors: Korol O A
Published: January 2020

The features of the repair and construction work during the overhaul of buildings are reflected in the development of organizational and technological design documents, which include calendar plans. Organizational and technological models represent the basis for the development and calculation of calendar plans, as well as for determining resource requirements. They for prevention works, the order of their implementation, the nature of the relationship between individual works, reflecting the specifics of the selected technology for the production of work and the features of the simulated object. The scheduling of overhaul works is carried out on the basis of the developed methodology, which allows obtaining rational organizational and technological solutions with a low level of certainty of the initial information. To evaluate the final set of alternative options for calendar plans and choose the best option in accordance with the described methodology, it is recommended to use quasi metric methods. This allows us to lay the foundation for the rhythmic and coordinated work of all units involved in overhaul at the stage of scheduling, as well as to keep track of the possibility of ensuring timely completion of the planned work.
BIM and QR-codes interaction on a construction site
Authors: Vasilyev R S , Losev K Y , Cheprasov A G , Bektash D T
Published: January 2020

The study presents the methods of construction site Quick Response Code (QR) codes implementation and gives suggestions to improve routine construction site tasks management. QR-code exchange data technologies are integrated into construction control system based on BIM providing availability of data, security and mutual cooperation on a construction site. The task of the study was to present Internet of Things (IoT) integration solution scheme, a mobile integration for data exchange system via QR-codes, using smartphones to scan and upload data about construction processes, and use “smart scanners” to process and print these codes as tags. These tags are to be attached to construction elements and equipment. It allows to control staff, machine and mechanisms movement, as well as follow up the stages of construction process. As a result, the statistics and advantages of working with smartphones over computers were considered. IoT integration solution scheme is presented. Except basic identification information BIM/QR-code subsystem should contain additional data associated with the Quality Management System (QMS) “quality records” on construction site. The scheme could be used as the basis of Enterprise Resource Planning (ERP) system together with construction control system and QMS within the IoT concept.
Crack resistance criterion of plane stress RC elements with prestressed reinforcement
Authors: Kolchunov V I , Iliushchenko T A
Published: January 2020

An analytical condition for crack resistance of a specific plane stress reinforced concrete element with prestressed reinforcement is considered in this article. The specific concrete element is reinforced with orthogonally located prestressed rods that coincide with the directions of the coordinate axes. The crack resistance condition is constructed by generalizing of G.A. Geniev theory of plasticity of concrete and reinforced concrete on the region of existence of tensile stresses: “tension-tension” and “compression-tension”. A graphical interpretation of this condition is presented for a plane stressed element depending on the angle between the main force and the coordinate axes. As an example, the crack resistance condition of the support zone of a prestressed concrete beam of a monolithic reinforced concrete frame is considered.
Manufacturing of the Oloid. CAD/CAM Workflow
Authors: Bellido Coope M
Published: January 2020

This paper considers the manufacturing process of the Oloid by means of numerical control machining. Firstly, the requirements of the end part were studied, and it was decided to manufacture the Oloid via gravity die casting, and its necessary mold to be produced by CNC machining. In order to do so, the gating system and mold had to be designed and tested using sand casting methods. When the test results were optimal the die was machined and the part cast. During this process the CAD/CAM workflow was object of observation and study, which allowed for insight and conclusions on the design process.
The properties of certain linear and nonlinear differential equations of the fourth order arising in beam models
Authors: Chichurin A , Filipuk G
Published: January 2020

The purpose of this paper is to present several new results concerning relations between linear differential equations of the fourth order and nonlinear differential equations of the fourth order. These equations are involved in the description of models of building structures, where there are beams with small deflections or curved axes. We consider linear differential equations of the second, the third and the fourth order and nonlinear fourth order differential equations related via the Schwarzian derivative. As a result, we obtain new relations between the solutions of these linear and nonlinear equations. For example, assuming that we know a solution of linear differential equation of the fourth order and a solution of the third order linear differential equation, then the Schwarzian derivative of their ratio solves certain nonlinear differential equation of the fourth order. We also present some conditions on the coefficients when this statement holds. Two more similar statements are presented. To illustrate theorems and our constructive approach we give two examples. The given method may be generalized to differential equations of higher orders.
The analysis of the polymer concrete characteristics by fractional calculus
Authors: Aleroev Temirkhan
Published: January 2020

The paper investigates a second-order differential equation with a fractional derivative in the lower term, in which the order of the fractional derivative is in the range from zero to two and is not known in advance. This model is used to describe oscillatory processes in a viscous medium. A fundamentally new method has been developed for the approximate solution of the first boundary-value problem for the equation of string vibration taking into account friction in a medium with fractal geometry. Considering that polymer concrete is a set of granules of a mineral filler located in a viscous medium, the equation of motion of these granules is derived and investigated. A technique is proposed for studying the motion of granules in a medium with fractal geometry.
Quasi-Static Solution of a Problem of Thermal Shock Acting on a Plate
Authors: Rogacheva Nelly , Suvorov Alexander
Published: January 2020

In most research works related to stress analysis of thin structures subjected to temperature change it is assumed that variability of temperature in time is limited. In classical theory of thermoelastic thin structures the case of strong dynamical effects is excluded from consideration. Under this assumption, from three-dimensional equations of thermoelasticity the equations of thermoelastic plates and shells of Kirchhoff-type are derived. In this paper we focus on the analysis of stress-strain state of a plate in strongly dynamical temperature field, for which the classical Kirchhoff theory is not suitable. The analysis is carried out by a mathematical method without making any hypotheses. A numerical example is considered.
Mathematical calculations of water saving during furrow irrigation of cotton using a screen from an interpolymer complex
Authors: Amanov B T , Gadaev N N , Ahmedjonov D G , Zhaparkulova E
Published: January 2020

This article discusses the mathematical model of furrow irrigation to establish irrigation rates when watering cotton through a screen from an interpolyme complex (IPC) with the addition of mineral fertilizers. By the change in “I” when watering cotton through a surface screen from IPC with the addition of mineral equations, we can say that physically the effect of the screen will affect the amount and rate of infiltration «I» and “ϑI
”, other relations do not change. In the case of placing the screen in the form of a thin film (as experiments show), soil infiltration decreases by approximately 3-3.5 times.
Modelling Fluidic Windows for Heating and Cooling
Authors: Fraaß Mathias , Su Lingqi
Published: January 2020

Recently, we introduced a transparent capillary glass panel fabricated by lamination of a structured glass sheet and a thin glass cover used for liquid circulation. Major applications of such device are room heating and cooling and energy harvesting for heat pumps. In order to model a façade of a building, a story of a building or even the entire building, simplified but accurate models for the temperature and the fluid flow distribution within the capillary panel as well as a device optical and thermal model are necessary. In this paper, our simplified models are introduced.
CFD Methods in Architecture and City Planning
Authors: Valger S A , Fedorova N N
Published: January 2020

The paper provides an overview of CFD solutions for architectural design and urban planning. Aspects of numerical modelling of the aerodynamics of buildings and structures are described. Examples of the influence of turbulence models on flow parameters in the vicinity of buildings, as well as examples of influence of thermal stratification regimes on flow structure around buildings and on concentration of gaseous emissions from low sources in the vicinity of these buildings are considered. The calculation results of aeration of a city micro-district and a scenario for the arrangement of green areas to change the wind regime of the territory with the already existing development are demonstrated in the paper.
A complexly method of GIS technologies and models used in the development of environmentally modes of hydraulic and hydropower facilities in Uzbekistan
Authors: Mukhammadiev M. , Nasrulin A. , Mukolyants A. , Ergasheva D.
Published: January 2020

In this article we consider the results of studying the problems and prospects of using information technologies to ensure the introduction of new innovative approaches in hydroecology and hydropower, the creation of GIS (GIS-geographic information systems) for hydroecological and hydro-technical monitoring, and also as a visual material for students studying the use of information systems in the development of environmentally acceptable modes of operation of hydraulic structures. The article was devoted to an actual theme - GIS-systems creation for hydro ecological monitoring as tool for support the information systems of the Aral Sea basin and optimisation models at development of ecologically applicable modes of exploitation of hydro technical buildings. It is possible and useful to use association of outputs from various scientific researches in one GIS-database as universal tool for modeling. As example of such approach can be consider as one interconnected system which combination results of work:

- System of water-salt balances in all rivers of Uzbekistan.

- System of digital maps and schemes that can be used in the development of environmentally acceptable modes of operation of hydraulic and hydropower facilities in Uzbekistan.

- The Aral Sea basin monitoring systems (ASBMS) as a digital system of hydroecological monitoring of quality of surface waters on basis ArcView.
Finite element modeling of fluid filtration in a deformable porous medium
Authors: Azhikhanov N T , Zhumagulov B T , Masanov Zh K , Bekbolatov A B
Published: January 2020

The scientific work considers the finite element modeling of fluid filtration in a deformable porous medium. A transversely isotropic medium has been taken as a deformable medium. Fluid filtration process to horizontal wells by drift type direction occurred in this transversely isotropic medium is studied. As filtration process goes, the stress layers are associated with the pressure, accordingly, equations have been shown regarding to this pressure. Numerical solution of the problem is carried out using the finite element modeling.
Characteristics of the plastic zones of the large-scale buildings soil foundation
Authors: Chunyuk D , Kurilin N
Published: January 2020

The particular scientific article contains the research of the form and adjustment of the plastic deformation zones, arising in the reactor building’s foundation, with due account of the nearby large-scale NPP buildings influence. The main feature of this research is the consideration of the stages of the ground foundation loading, modeling the process of the buildings construction. Four different versions of the most common sequences of loads were simulated in the calculations. The research was performed using the finite element method in nonlinear statement with application of the Mohr – Coulomb model. Based on the results of the calculation, the most favorable variant of the large-sized NPP buildings foundation was selected, also, was analyzed the form of the plastic deformation zones.
Study of the composite action of concrete and reinforcement in the floor in case of emergency impact
Authors: Mkrtychev O V
Published: January 2020

The article presents the results of a numerical study of the composite action of concrete and reinforcement in reinforced concrete flooring under emergency loads, taking into account physical and geometric nonlinearities. The study used a nonlinear static method in the LS-DYNA software package, which implements the Continuous Surface Cap Model (CSCM). The simulation model of a monolithic beam floor uses volumetric finite elements for concrete and rod elements for reinforcement. Isofields and graphs of the intensity of stresses and strains in the upper and lower reinforcement, as well as in the concrete at the floor elevation, with an increase in the vertical uniformly distributed load, were built. The load-bearing capacity of the monolithic slab under consideration was determined using the non-collapse criterion. The LS-DYNA software package makes it possible to study the action of load-bearing concrete structures modeling direct concrete reinforcement using reinforcing bars at a significantly nonlinear nature of strain.
Piezoelectric Stacks as an Effective Gauge of Small Dynamic Strains
Authors: Rogacheva N.N.
Published: January 2020

The theory of a new piezoelectric gauge of small dynamic strains is developed. The first previously proposed piezoelectric gauge is a thin piezoelectric element with preliminary polarization in the direction of its thickness. As a new gauge, piezoelectric stacks are used. Its direction of preliminary polarization coincides with the direction of the measured strains. As shown in the paper this kind of piezoelectric composite gauge can significantly increase the value of the measured electrical signal and the accuracy of the measured strains. Piezoelectric laminated stacks has a periodic structure, therefore, the homogenization method is used to correctly determine its effective characteristics (physical constants).
Application of modern modeling methods: virtual technologies in the era of digitalization and their role in modern companies
Authors: Lyapuntsova E V , Vdovichenko M , Belozerova Yu , Gorbatov A
Published: January 2020

The main research issue is the use of modern modeling methods: virtual technologies in the digital age and their role in modern companies. The aim of the study is to determine the degree of demand for virtual technologies in the modern market as an informational benefit of industrial purposes. Thus, we can talk about significant prospects for increasing the attention of both business structures and social institutions to the implementation of virtual reality technologies in their business processes in order to increase business efficiency and attract attention to innovative solutions.
Optimization of calculation of the stress-strain state of a base reinforced with inert material
Authors: Ter-Martirosyan A Z , Sergeev S A , Ermoshina Yu L
Published: January 2020

In this article, we performed a comparative analysis of the results of calculating the stress-strain state of a soil base reinforced with crushed stone columns, with calculation results obtained using a well-known technique that allows optimizing the calculation of the deformation characteristics of base soils. The calculations were performed by the finite element method (FEM) in the PLAXIS 3D software package. The base reinforcement was carried out in order to reduce the stabilized settlement by transforming the properties of the soil using crushed stone reinforcing elements. A comparative analysis showed good convergence of the values of the settlements of slab foundations, which allows us to apply the methodology for calculating the deformation characteristics of soils to optimize the calculation of the stress-strain state of the bases according to the second group of limiting states.
The analysis of existing neural networks for natural language interfaces
Authors: Pilyay A , Shilova L
Published: January 2020

This paper discusses the main types of neural networks and describes which are most suitable for solving problems within the framework of natural language user interfaces. The statistics of publications on the use of neural networks in various branches of science for the period from 2015 to 2020 are given, assumptions about the possible directions of integration of neural networks in the construction industry are made.
Mathematical and computer modeling in the design of steel rod structures
Authors: Vasilkin A
Published: January 2020

The article considers the problem and search solution of an optimal variant of the design of steel structures based on the use of computer technology and mathematical modeling. As a method of search of the optimal solution, the method of parametrical optimization is used. The application of the method is illustrated on the example of a flat rod design - a truss construction. The variable parameters were selected to build a gruph for changing the target function. The novelty of the study lies in the fact that as a criterion of optimality, the cost of its production was adopted, at that time, how often is the weight of the structure taken. As a result of the conducted research it was found that the difference in production cost at application of different types of outlines of belts makes up to 20%. For criteria of an optimality metal consumption and production cost were received various versions of the optimal solution that tells about the important role of the chosen criterion and the need of the accounting of bigger quantity of elements to compose the optimality criterion. Efficiency and expediency of use of computer technologies to design steel structures is shown. That gives the engineer necessary information for adoption of reasonable design decisions on the basis of the analysis of alternative options.
The longitudinal-transverse bending of multilayered concrete rods taking into account the influence of gravity
Authors: Nemirovskii Yu V , Tikhonov S V
Published: January 2020

The paper considers the problem of longitudinal-transverse bending of a multilayered concrete rod taking into account the influence of gravity. The law of deformation of each layer of the rod is adopted in the form of approximation by a polynomial of the second order. The main purpose in this work is to study the influence of gravity on the ability of the rod to withstand the applied loads. In this work, the achievement by the maximum deformation the limit allowable value in one or several layers of the rod under tension or compression, corresponding to the points of transition to the descending branch in the deformation diagram, is accepted as a criterion for the conditional limit state. The approximate solutions of these problems are found by the Bubnov-Galerkin method.
Deformation of beam structures in an internal explosion
Authors: Gorev V A
Published: January 2020

The paper considers the deformation of a hinged beam exposed to the action of an explosive load at the initial stage of an internal explosion, when the excess pressure increases according to the third degree of time. With this law of load change, the rate of its increases all the time, which leads to an increase in dynamism. Analytical expressions are obtained for the deformation value and its velocity, both at the growth stage and at the pressure drop. The case of transition of elastic deformation to plastic deformation both at the stage of load growth and decline is considered. The decline was approximated by a linear function of the start time of the decline. Calculations have shown that the deformation rate increases significantly towards the end of the lifting stage. If plastic deformation occurs at the stage of lifting close to its end, the coefficient of plasticity is close to 10 or more. If plastic deformation occurs at the stage of decline, the coefficient of plasticity varies between 1.4÷2.
Calculation and experimental substantiation of optimal sizes of large-size tanks filled with bulk material
Authors: Fedorova T G
Published: January 2020

The numerical calculation of elastic-plastic deformation and limiting States of shell structures of large-size tanks filled with bulk material is carried out. The solution of a three-dimensional geometrically and physically nonlinear problem is based on the finite element method and an explicit cross-type time integration scheme. The critical load at which the tank loses stability is determined. The influence of the length of the tank on its stability is investigated.
Analytical methods of theoretical physics in the modeling of building structures
Authors: Gulkanov A , Modestov K
Published: January 2020

In this paper, on the basis of the variational principle of the least Hamilton action, the field-theoretic Lagrange equations of the 2nd kind are derived in the presence of a dependence of the density of the Lagrange function on the higher derivatives. On the basis of the obtained equations, written in terms of variables that most fully reflect hypotheses and used assumptions, the equations of continuum mechanics are obtained and the Timoshenko, Rayleigh and Euler-Bernoulli beam models are calculated. It is shown that the method used leads to a more efficient method of obtaining partial differential equations describing the dynamics of deflection of beams. The possibility of taking into account the distributed load and the elastic base in the Lagrangian formalism is noted. The possibility of further development of analytical and theoretical-physical methods in application to mathematical modeling of building structures is analyzed.
Influence of geothermal environment on the corrosion fatigue behaviour of standard duplex stainless steel X2CrNiMoN22-5-3
Authors: Wolf Marcus , Pfennig Anja
Published: January 2020

In the geothermal environment corrosion fatigue may severely lower the lifetime expectancy of high alloyed steels. Therefore, the corrosion fatigue (CF) of duplex stainless steel X2CrNiMoN22-5-3 was investigated in the Northern German Basin electrolyte at 369 K using a specifically designed corrosion chamber. Although the failure mechanism is independent of surface roughness (low scatter ranges technical surface: TN=1:1.35, polished surface: TN=1.1.95), the life expectancy in purely alternating axial cyclic load to failure was clearly related to surface finish and applied stress amplitude. Specimen with technical surfaces tested at high stress amplitudes (>275 MPa) lasted longer (cycles to failure: P50% at Sa 300 MPa=5x105) than specimen with polished surfaces (cycles to failure: P50% at Sa 300 MPa=1.5x105). When applying a protective potential a significant increase of CF life range from 4.7 x 105 (free corrosion potential) to 107 cycles (potential range from USHE = –450 to – 900 mV) was observed. Microstructural analysis of the CF damage revealed horizontal grain attack within corrosion pit cavities, multiple fatigue cracks and preferable deterioration of austenitic phase. At low stress pitting is the initiating crack growth process whereas at high stress amplitudes the formation of micro cracks is reason for crack propagation and failure.
Interaction of whole fiber and destroyed neighbour fiber in reinforced plastic
Authors: Turusov R , Bogachev E , Andreev V
Published: January 2020

Composite materials, both on the basis of polymeric binder, and other materials, for example, concrete are widely distributed. The paper considers the case of longitudinal location of elements. The paper deals with the question the intensity of the adhesive interaction, of course, with the true strength of the adhesive bond. To study the interaction of two adjacent fibers, whole and broken in work, it is proposed to use the concept of a contact layer [1 – 4]. To study the interaction two adjacent fibers, whole and torn, we propose use the concept of contact layer. This anisotropic layer has a certain thickness, equal to the length of the bonds, the shear modulus in the contact plane, and the Young’s modulus along the rod-bonds. In fact, it is an anisotropic continuous medium. When solving one-dimensional problems, the shear modulus and thickness of the contact layer are combined into one parameter, whose influence is decisive on the distribution pattern and stress intensity near the edge. This parameter can be determined quite easily from a macro experiment.
Stability of Ladders when Working at heights and Safety while performing this type of work
Authors: Pham N T , Vasilenko V V
Published: January 2020

The analysis of industrial injuries when working at heights is conducted. Statistics show that a fall from a height takes more than 30% of the total number of accidents. Operations with the help of ladders are the most common type of works at heights. However, the ease of installation and use of ladders often leads to the fact that the persons performing the work do not pay enough attention to safety. The aim of the work was to improve the safety in operation at heights with the use of ladders inclined to the horizontal surface. An important prerequisite for the safe use of ladders is to ensure their stability. There were analyzed the most common devices used to increase the stability of ladders. The issue of applying a lifeline system attached to a ladder (if the ladder is affixed to a building or other structure), when working with a ladder at heights of more than 1.8 m, is considered. The inferiority of this issue is shown in the current regulatory documents. It was proposed to revise the relevant requirements in the regulatory documents on the possibility of using a lifeline system attached to the ladder, requirements for the durability of the ladders and methods of their testing.
Low-cycle Fatigue of High Processible Aluminum Alloy Flat Products from Alloyage System Al-Mg-Si
Authors: Shuvalov Aleksandr , Katanina Alla , Kornev Oleg , Kovalev Mikhail
Published: January 2020

Resistance to low-cycle fatigue of hot-rolled plates manufactured from alloyage system Al-Mg-Si alloy 6082 is researched. Cyclic stability of alloy and cyclic proportional elastic limit were defined during tests of specimens without cracks loaded along the rolling direction using curves of cyclic strain and their generalization. Properties used for design of prefabricated structures from thick aluminum plates from alloy 6082 operating in the conditions of low-cycle fatigue are received.
Strength, chloride resistance and corrosion reinforced of High-strength concrete
Authors: Xuan Hung Ngo , Van Lam Tang , Bulgakov B I , Alexandrova O V
Published: January 2020

Typical low-calcium fly ash (LC-FA) and silica fume SF 90 (SF-90) was used as a binder in the mixture of high-strength concrete (HSC), replacing (20-40)% and (5-15)% of the weight of Portland cement, respectively. The slump of fresh HSC mixtures, compressive strength, density and water absorption of HSC samples were investigated. Applying the standard NT Build 356 combined with standard ASTM C1202-97 for assessment of the chloride resistance and the corrosion resistance reinforced of tested concrete produced using high-calcium fly ash and Silica fume was studied in this work. The results show that the compressive strength of examined concrete decreased with increasing LC-FA content and was lower than the concrete used mix control, while the compressive strength of concrete mixtures with SF-90 at 5%, 10% and 15% by mass cement was higher than the sample tested with mix control and significantly higher than the LC-FA concrete mixtures. LC-FA and SF-90 in HSC decreased the charge passed and tends to decrease, while the times of initial crack of the test specimens gain increased with increasing LC-FA and SF-90 contents. The chloride ion penetrability of HSC is very low.
Effect of the soil pressure and that of filtration forces on a triangular retaining wall
Authors: Agakhanov E , Agakhanov M , Begov N
Published: January 2020

The filtration forces considered as the forces determining the form and the performance characteristics of full-scale hydro-engineering gravity structures have a significance comparable with that of the main effects: the hydrostatic pressure and the own mass of the structure. The examples of determination of the stress state caused by filtration forces through the modelling method include the recommendations on the replacement of the aforesaid effects by the surface loadings applied to the gravity centre of their projections. This method reduces the accuracy of the results and requires (like with the construction of backpressure lines) the tests of many models. The authors carried out the modelling of the effect of the soil pressure and that of filtration forces in accordance with the modelling methodology based on the equivalence of effects. The article contains a solution for a retaining wall with a triangular cross-section under the effect of the soil pressure on the vertical side and that of volume filtration forces.
Foamed concrete containing various amounts of organic-mineral additives
Authors: Kim Dien Vu , Cong Ly Nguyen , Van Lam Tang , Bazhenova S I
Published: January 2020

The present study evaluated the combined effects of organic-mineral additive based on a superplasticizer SR 5000F and the active mineral additive Fly Ash, Blast Furnace Slag and Silica Fume SF-90 on properties of foam concrete (FC). The calculation of mixture proportions of FC is applied in accordance with the absolute volume method. Besides, the compressive strength and flexural strength of foam concrete are determined by Russian standard GOST 10180-2012. The results from experiments show that flexural and compressive strength of the FC obtained respectively, from 3.25 to 5.08 MPa and from 13.91 to 26.87 MPa. The use of an organic-mineral additive in the mixture was led to increasing the compressive and flexural strength of foam concrete at the age of 28 days, respectively, from 8% to 93% and from 6% to 56%. The relationship between compressive strength and curing age, compressive and flexural strengths of the FC were also determined in this investigation. The results of this study demonstrated that the use of appropriate amounts of fly ash and blast furnace slag to partially replace natural sand could produce eco-friendly foam concrete, which has many positive environmental impacts.