bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microcrack appearance and coefficient of tension intensity ceramsite concrete on multicomponent binding
Authors: Kravchenko S A , Posternak O O , Kostyuk A I , Stolevich I A 
Published: July 2021

Abstract
The results of experimental research of microcrack appearance and coefficient of tension intensity of experimental patterns from ceramsite concrete on multicomponent binding and quartz sand are given. Optimal compositions of construction and heat insulation ceramsite concrete on multicomponent binding are presented. Methodology of experimental researches, parameters of experimental patterns with description of technology of their making, results of basic patterns tests and their analysis, and also volume, aims and results of auxiliary standards tests are described. In the process of tests the longitudinal and transversal deformations of patterns, value of crack appearance loading, size of the destroying loading were measured. The done experimental researches of limits of microcrack appearance and coefficient of tension intensity of patterns from ceramsite concrete on multicomponent binding allowed to educe the characteristic features of their tensely-deformed state, to define the high and lower bound of crack appearance, deformability and size of the destroying loading of experimental patterns.
Influence of the chemical composition of blast-furnace slag on the whiteness of decorative slag-alkaline cements
Authors: Krivenko P V , Gelevera A G , Kovalchuk O Yu , Rogozina N V 
Published: July 2021

Abstract
The construction industry is demanding more and more quality decorative cements. The demand for them and the requirements for their performance are constantly growing. But since decorative cements are based on white Portland cement, their production is associated with the shortcomings of the production of all clinker cements – low environmental friendliness, high energy consumption and high prices. They are not always able to provide decorative ecological and comfortable coatings with increased performance. In addition, many countries do not produce it and have to import it.
An effective alternative to decorative clinker cements can be decorative slag-alkaline cement obtained from industrial waste. It also provides a number of special properties – a wide range of colors, color fastness, high strength, high adhesion, durability and many others.
But the problem associated with the use of slag-alkaline cements as decorative cements with high whiteness (≥ 70%) is the instability of the chemical composition of the slag and, first of all, the different presence of iron oxides in it.
The paper shows the regularities of the influence of the chemical composition of blast-furnace slags on the whiteness of an artificial slag-alkaline stone. A new method for determining the whiteness of hardened materials is proposed. Possibilities of obtaining decorative alkali-activated cements with a wide range of whiteness – from 70 to 97% are shown.
Stability of compressed rods when their stiffness changes according to the law of the fourth power
Authors: Krutii Yu , Surianinov M , Shyliaiev O 
Published: July 2021

Abstract
Based on the previously obtained representations for the state parameters of a rod with arbitrary continuous bending stiffness, the stability problem for a family of rods whose stiffness varies according to the law of the fourth power is solved. The spectrum of critical forces is determined and formulas for curved forms of equilibrium are derived. We propose to consider the stability coefficient as a function of the variable α, and having a set of values of this function corresponding to the values of the independent variable 0 < α ≤ 1, approximate the function K by a polynomial. The result is the expression K
2 = 0.0001α + 80.7626α
2 + 0.0002α
3. The power of the polynomial was chosen from the condition that the coefficient of determination should not be less than 0.9999. The directions for further research are presented: introduction of the results of this work into the practice of calculations for stability of real objects; application of general formulas for state parameters to the study of stability of rods with other laws of change in transverse stiffness encountered in practice.
Lightweight concrete for frame-monolithic construction
Authors: Ksonshkevych L M , Barabash I V , Streltsov K O , Krantovska O M 
Published: July 2021

Abstract
The proposed article is devoted to the study of the properties (strength, impact strength, sound absorption) of lightweight concrete used for frame-monolithic construction. Characterized by the well-known advantages (reduced load on the foundation, reduced consumption of reinforcement, as well as improved heat and sound isolation), lightweight concrete requires additional technological methods to achieve the necessary mechanical characteristics - compressive strength and impact strength. An alternative to the traditional preparation of concrete mixtures is proposed a technology using a high-speed mixer-activator in the presence of ground chamot, superplasticizer C-3 with the introduction of hydrophobic expanded clay gravel up to 75% of the amount of granite crushed stone. The use of mechanical activation leads to an increase in impact strength by 44% compared to the control, and makes it possible to obtain concretes, the sound isolation level of which provides the maximum efficiency of impact noise isolation and is equal to 45.7 - 42.8 dB in three frequencies, and the sound absorption level is 39. 8 - 49.7 dB.
Influence of modifying additives on properties of the powder coatings
Authors: Gots V , Lastivka O , Berdnyk O , Tomin O 
Published: July 2021

Abstract
The study deals influence of modifying additives on properties of the powder coating. The authors Using rheological and degassing modifying additives with different nature of the main active substance. It was found that the additives based on the acrylate polymer adsorbed on the silicon dioxide in the form of Byk-3900P and on the polyoxyethylene derivative of the castor oil in the form of Luvotix R400 decreasing the surface tension in the coating film, which, in its turn, contributes to the increase in the wettability of base during the melting of the powder coating, decrease the ‘orange peel’ effect during the cross-linking, reduction in pinholes on the obtained surface and improvement of mechanical characteristics of the coating. At the same time, rheological additives based on the bentonite in the form of Luvogel 4B and on the hydrophilic silicon dioxide in the form of Cab-o-sil M5 cause the increase in the surface tension in the coating film, which, in its turn, leads to the worsening of flow, appearance and mechanical characteristics of the powder coating.
Improvement of methods for assessing the reliability of axle boxes for freight cars
Authors: Martynov I , Trufanova A , Shovkun V , Babenko A , Kladko N 
Published: July 2021

Abstract
The box bearing unit of the freight car is a complex mechanical system, which is influenced by various factors. Under normal operation, the parameters characterizing the functional state of the components of the axle box should be within the prescribed limits throughout the standard service life. Mathematically, this corresponds to the placement of the axle box elements in the space of admissible states. The railroad model consists of a set of submodules: track and elastic ballast layer. The model allows simulate the microgeometry of the track, the characteristics of the inequalities, and the elasticity of the base under the track. Subsequently, the main parameters characterizing random processes were determined: the magnitude of the mathematical expectation, the variance, as well as the minimum and maximum values of the effort. The results indicate that random processes are distributed according to normal law. According to the results of the research, for each of the random loading processes of the axle boxes, appropriate correlation functions were constructed and the space of “admissible states” for different operating modes was con-structed.
Evaluation of electromagnetic radiation shielding characteristics of facing building vaterials
Authors: Panova O V , Krasnianskyi G Iu , Aznaurian I O 
Published: July 2021

Abstract
The article presents the results of theoretical studies of the protective properties of composite facing materials based on a dielectric matrix with an electrically conductive non-magnetic filler in a wide frequency range of incident electromagnetic radiation. Expressions are got for the values of the transmission, reflection and absorption, and the electromagnetic radiation shielding efficiency calculated on their basis. The dependences of the permittivity and electrical conductivity of the composite on the volume fraction of the electrically conductive additive required for calculations were got based on the hypothesis of similarity, considering the nonzero conductivity of the dielectric matrix. Satisfactory agreement between the calculation results and the measured shielding characteristics of specimens of metal silicate materials based on calcium hydro silicates and copper powder was established. The results presented show the adequacy of the proposed calculation method and indicate that it can be used for preliminary estimates of the shielding characteristics when designing electromagnetic radiation shields based on composite facing materials.
Biomechanics of self-loosening of the screw that connects the intraosseous part of the implant and the abutment with the orthopedic structure attached to it
Authors: Semenov Ye , Surianinov M 
Published: July 2021

Abstract
The results of the study of the stress-strain state in the elements of the system “intraosseous part of the implant - screw - abutment with an orthopedic structure fixed on it” under different given conditions of its functioning are presented. We have determined the stress-strain state in the crown neck area, which replaces the upper jaw central incisor, in the presence of the natural wear (0.5 mm) of the teeth and anthropoid teeth next to the implants and the same nine load variants as in the initial non-prosthetic model, i.e. a total of 54 calculation experiments have been carried out. It has been established that the occurrence of such secondary mechanical complication of dental implantation as loosening of the screw connection between the intraosseous part of the implant and the prosthetic structure fixed on the abutment influences the type of teeth clamping (bite), the angle of the preferential transfer of chewing load, the propensity and the wear ability of the teeth. The most unfavourable, in terms of the value of the torque that unwinds the fixation screw, is the direct occlusion of the teeth and the angle of the preferential load transfer of 1450 (Mpr = 1.16 Nm), or 3.87% of the twisting torque value. At the same conclusions of the set parameters and the value of erosion of its teeth 0.5 mm the value of the torque, which untwists, increases by 5 times and corresponds to 19.3% of the initial torque (30 Nm) and will inevitably lead to its untwisting.
Indentation of an elastic half-space by the cylindrical flat punch with a rounded edge under non-monotonic loading
Authors: Streliaiev Yu , Titova O 
Published: July 2021

Abstract
The paper presents a novel approach to solving the contact problem for interaction with friction between a rigid cylindrical flat punch with rounded corners and a linearly elastic half-space. Increasing and decreasing normal loads act on the punch sequentially. Coulomb’s law is used to account for friction. The contact problem is reduced to nonlinear operator equations that must be solved at each step of the discrete loading process. The numerical method is applied. This method includes regularization of the equation, discretization of the regularized equations and the usage of an iterative process to obtain the approximate solution. The calculations were performed for different values of the relative radius of the flat area of the punch base. Distributions of contact traction and configuration of the stick and slip zones are studied at each monotonic stage of the loading process.
Accounting for dissipation of the energy of the supple base
Authors: Telipko L P , Yu Solod V , Romaniuk A D 
Published: July 2021

Annotation
When calculating the foundations and structures on a compliant basis for the action of dynamic effects, the mathematical model of the base should reflect the real conditions for deformation of the base, due to their lamination, limited by the distribution property, weight and others. This is more, in our opinion, the axisymmetric columnar model of a compliant base is responsible, which takes into account the important properties of the ground base at a dynamic effect, as the extremity of the oscillation distribution zone and its inertia. In this case, the model allows us to determine not only the movement of the boundary plane, but also the stress-strain state of the base. With resonant phenomena, the accounting of energy dissipation during oscillations of the base is essential. The paper discusses the adaptation of the axisymmetric columnar model on a dissipative base, in which the dispersion of energy is carried out according to the complex hypothesis by E.S. Sorokin. The model in question is a cylindrical body in the form of a rod height H and radius R, large enough to believe that the amplitudes of displacements on the cylindrical surface of the rod are zero, when the rod on the outer end is loading within the centrally located circular area with a radius r, much smaller R. The basis, obeying the three-axis linear physical law, is in the conditions of axial symmetry, therefore, only vertical u and radial w movements are observed, which are functions of variables x, r, t. The solution of the dynamic Liame equations described by the deformation of the cylindrical body was carried out by the discrete method of L.V. Vinokurov, according to which the solution was found in an analytical form in the variable x, and in the variable r - in the finite-difference. The use of a method of separation of variables by Fourier, a system of discrete differential equations in private derivatives was reduced to a system of differential equations in ordinary derivatives, the integration of which was carried out using Euler substitutions. Permanent integration was determined from the boundary conditions at the end of the cylindrical rod. The solutions obtained show that energy dissipation accounting causes a phase shift between the perturbing load and the movement of the base and to a significant decrease in the amplitudes of oscillations in the resonance zone.
Aggregation of identical mechanical systems with oscillations
Authors: Barabanov I N , Tkhai V N 
Published: July 2021

Abstract
We consider identical mechanical systems described by Lagrange’s equations of the second kind and subject to the action of positional forces. It is assumed that a separate system allows for single-frequency oscillation. The problem of aggregating the set of systems into a coupled system with an attractive cycle close to the oscillation of uncoupled systems is solved. For this purpose, weak universal coupling controls are found.
Stress-deformed state of vertical cylindrical metal shell under temperature climate impact
Authors: Zhdanov A A , Petrov V N 
Published: July 2021

Abstract
There are continued the previous executed researches of the tense-deformed condition of a vertical metal thin cylindrical shell under temperature climatic influences in this work. So, in [1] the temperature climatic influences on cylindrical metal shells are investigated, in [2] the parameters of the elastic base simulating the wheat repulse are investigated, in [3] the tense-deformed condition of a shell on the elastic base with piecewise-constant is investigated, and in [4] with a piecewise-linear Winkler coefficient for axisymmetric cooling of the shell. The tense-deformed condition of a vertical cylindrical thin-wall shell lies on a piecewise-constant elastic base under non-axisymmetric temperature climatic influences has been studied in the present study on the basis of membrane theory of shells and a simple edge effect. The decision is received in the Fourier series, containing in the general case of heating-cooling the shell, ten members of the Fourier series.
Cracks and their role in the life cycle of building materials
Authors: Vyrovoy V N , Sukhanov V G , Korobko O A , Sukhanova S V 
Published: July 2021

Abstract
Cracks as active elements are presented in all building structures. Cracks define a spontaneous internal restructuring of the structure of the construction material. This is a necessary condition for the adaptation of the system to the influence of unfavorable factors. The presence of active elements in the material of the structure-system contributes to its structural development, which indicates the creative role of cracks. Upon reaching the maximum variety of the structure, cracks-creators are able to develop to cracks of destruction. Cracks-destroyers should be considered as open complex self-organizing systems with their own life cycle. The predominance of the goal of the new crack-system over the goal of the existence of the structure-system leads to the failure of the structure as a basic system.
Understanding small ORF diversity through a comprehensive transcription feature classification
Authors: Guerra-Almeida Diego , Tschoeke Diogo Antonio , Nunes-da-Fonseca Rodrigo 
Published: July 2021

AbstractSmall open reading frames (small ORFs/sORFs/smORFs) are potentially coding sequences smaller than 100 codons that have historically been considered junk DNA by gene prediction software and in annotation screening; however, the advent of next-generation sequencing has contributed to the deeper investigation of junk DNA regions and their transcription products, resulting in the emergence of smORFs as a new focus of interest in systems biology. Several smORF peptides were recently reported in non-canonical mRNAs as new players in numerous biological contexts; however, their relevance is still overlooked in coding potential analysis. Hence, this review proposes a smORF classification based on transcriptional features, discussing the most promising approaches to investigate smORFs based on their different characteristics. First, smORFs were divided into non-expressed (intergenic) and expressed (genic) smORFs. Second, genic smORFs were classified as smORFs located in non-coding RNAs (ncRNAs) or canonical mRNAs. Finally, smORFs in ncRNAs were further subdivided into sequences located in small or long RNAs, whereas smORFs located in canonical mRNAs were subdivided into several specific classes depending on their localization along the gene. We hope that this review provides new insights into large-scale annotations and reinforces the role of smORFs as essential components of a hidden coding DNA world.
Management and outcomes of esophageal perforation
Authors: Axtell Andrea L , Gaissert Henning A , Morse Christopher R , Premkumar Akash , Schumacher Lana , Muniappan Ashok , Ott Harald , Allan James S , Lanuti Michael , Mathisen Douglas J , Wright Cameron D 
Published: July 2021

Summary

Background
Esophageal perforation is a morbid condition and remains a therapeutic challenge. We report the outcomes of a large institutional experience with esophageal perforation and identify risk factors for morbidity and mortality.

Methods
A retrospective analysis was conducted on 142 patients who presented with a thoracic or gastroesophageal junction esophageal perforation from 1995 to 2020. Baseline characteristics, operative or interventional strategies, and outcomes were analyzed by etiology of the perforation and management approach. Multivariable cox and logistic regression models were constructed to identify predictors of mortality and morbidity.

Results
Overall, 109 (77%) patients underwent operative intervention, including 80 primary reinforced repairs and 21 esophagectomies and 33 (23%) underwent esophageal stenting. Stenting was more common in iatrogenic (27%) and malignant (64%) perforations. Patients who presented with a postemetic or iatrogenic perforation had similar 90-day mortality (16% and 16%) and composite morbidity (51% and 45%), whereas patients who presented with a malignant perforation had a 45% 90-day mortality and 45% composite morbidity. Risk factors for mortality included age &gt;65 years (hazard ratio [HR] 1.89 [1.02–3.26], P = 0.044) and a malignant perforation (HR 4.80 [1.31–17.48], P = 0.017). Risk factors for composite morbidity included pleural contamination (odds ratio [OR] 2.06 [1.39–4.43], P = 0.046) and sepsis (OR 3.26 [1.44–7.36], P = 0.005). Of the 33 patients who underwent stent placement, 67% were successfully managed with stenting alone and 30% required stent repositioning.

Conclusions
Risk factors for morbidity and mortality after esophageal perforation include advanced age, pleural contamination, septic physiology, and malignant perforation. Primary reinforced repair remains a reasonable strategy for patients with an esophageal perforation from a benign etiology.
Unilateral versus bilateral cerebral perfusion during aortic surgery for acute type A aortic dissection: a multicentre study
Authors: Piperata Antonio , Watanabe Masazumi , Pernot Mathieu , Metras Alexandre , Kalscheuer Gregory , Avesani Martina , Barandon Laurent , Peltan Julien , Lorenzoni Giulia , Jorgji Vjola , Gregori Dario , Takahashi Shinya , Labrousse Louis , Gerosa Gino , Bottio Tomaso 
Published: July 2021

Abstract

OBJECTIVES
The aim of this retrospective multicentre study was to investigate and compare clinical outcomes of unilateral and bilateral antegrade cerebral perfusion (ACP) strategies on cerebral protection during surgery for type A aortic dissection.

METHODS
Data from 646 patients who underwent surgical repair of thoracic type A aortic dissection using unilateral and bilateral ACP with moderate hypothermic circulatory arrest in 3 cardiac surgical institutions between 2008 and 2018 were analysed. Propensity matching was performed to assess which technique ensured better outcomes.

RESULTS
Unilateral and bilateral ACP techniques were performed in 250 (39%) and in 396 (61%) patients, respectively. Propensity score analysis identified 189 matched pairs. In the matched cohort, the lowest core temperature was 27.5°C and 28°C in the bilateral and unilateral groups, respectively (P &lt; 0.001). The unilateral technique required significantly shorter aortic cross-clamp and cardiopulmonary bypass times than bilateral technique [82 min vs 100 min (P &lt; 0.001); 170 min vs 195 min (P &lt; 0.001)]. The 30-day mortality was comparable (P = 0.325). The bilateral group reported a significantly higher incidence of permanent neurologic deficits (P &lt; 0.001), left brain hemisphere stroke (P = 0.007) and all-combined complications (P &lt; 0.001). Ten-year survival was comparable (P = 0.45).

CONCLUSIONS
Unilateral and bilateral ACP are both valid brain protection strategies in the landscape of aortic arch surgery. While admitting all the study limitations, unilateral technique could offer some clinical advantages.

Clinical registration number
76049