bluuebunny/crossref_metadata_2025 huggingface dataset:
Justification of Safe Operation of Rolling Stock by the Lifetime of Its Bearing Structures
Authors: Oganyan E S , Volohov G M , Gasyuk A S
Published: March 2021

The problem of providing strength and reliability of rolling stock bearing structures which include welded and cast parts of bogie frames and bodies of cars and locomotives, as well as brackets and attachment points for their equipment and traction drive units, is one of the most important in the design, construction and operation. The development of high-speed and heavy-haul traffic, as well as the introduction of requirements for determining the design service life and life time of railway transport facilities, make the above task even more urgent. The influence of the operational loading characteristics of the object on the safety factor of fatigue strength and its depletion: amplitudes of cyclic stresses, frequencies of their change, parameters characterizing the intensity of the rolling stock operation (number of loading cycles, speed of movement, average daily mileage) is shown based on the results of computational and experimental studies carried out with running dynamic and strength tests of locomotives at all operating speeds of their movement in operation.
Calculation of Inter-Column Slabs Bearing Capacity by Kinematic Method
Authors: Pavlikov A M , Harkava O V , Pinchuk N M
Published: March 2021

The method of bearing capacity calculation of the inter-column slabs of flat slab frame system is developed by a kinematic way based on the ultimate equilibrium method. The basis of the study is the kinematic method of the limit equilibrium method and its application to calculate the load-bearing capacity of the inter-column slab in flat slab structural system, as well as to select the area of the working reinforcement. Attention is also paid to establishing the location of the lines of plastic hinges formation.
Lothenbach’s Model of Von Mises Stress Distribution in Portland Cement in Curing and Temperature Gradient Conditions
Authors: Abzaev Yu A , Gnyrya A I , Korobkov S V
Published: March 2021

The paper presents the two-dimensional Lothenbach’s model of Portland cement curing based on the finite element method. The cement curing lasts for 7 days in the temperature gradient conditions ranging from 65 to −20 °C. A cement rod 7×70 cm in size is used for modelling the temperature and von Mises stress distributions. It is shown that in the temperature gradient and curing conditions, the stress maximum in Portland cement shifts toward the hot edge of the cement rod and exceeds the minimum stress level more than two times. The stress growth is significant at the interfaces between the concrete timber and the cement rod, especially at its cold edge. Such a distribution of von Mises stress is connected with the heat flow generation and their superposition with reverse heat flows. At the interfaces, superposition of the negative heat flows generates higher stresses, than superposition of the positive heat flows. The concrete timber and the interface stability are the additional factors that increase the stress level and contribute to the fracture of the pore walls.
Research of the Degradation Process of Reinforced Concrete Structures
Authors: Varlamov A A , Rimshin V I , Davydov A , Minnatov A R , Kurbatov A M
Published: March 2021

The various impact on the durability of concrete and reinforced concrete structures is determined. Three groups of factors are identified that affect the assessment of the durability of reinforced concrete: a) elastic, b) strength, c) crack strength. Based on the analysis, the determining influence of the crack strength factor on concrete degradation was identified. A new method is proposed based on the analysis of existing methods for determining the characteristics of concrete crack strength. The method allows evaluating the crack strength (fracture toughness) of concrete and reinforced concrete structures in any of their conditions. (A method is proposed and a description of samples for implementing the method is given.) Standard formulas were used to evaluate characteristics of crack strength based on prismatic specimens extracted from concrete. Comparative tests of samples were carried out according to the known and proposed method. The obtained characteristics are used to assess the condition and durability of buildings and structures.
Forming Typical School Architecture in the USSR Depending on Educational System Development Process
Authors: Zadvernyuk L V
Published: March 2021

In the 20th century a design of schools in Russia was subject to critical transformations. Each of them was a response to the development of the system of a comprehensive secondary education. The architecture of school buildings also transformed and changed from the comprehensive schools for the vocational profession training to complex educational institutions with a flexible layout. The objective of the research is to identify the dependence of school architecture on the needs of the state education system. The analysis of correlation processes between the education system and volumetric&spatial composition in the architecture of school buildings (exemplified by typical projects) allows showing the architectural practice response to the education system needs. The development of the unified school architecture in the USSR is justified not only from the positions of economic profit but also from the positions of a country-wide mass school construction. A school building model was formed in typical projects and was intended for providing a necessary space for everybody. The identified interdependence of the school education system and architecture today makes it possible to develop a modern invariant for a volumetric&spatial design of a school building accessible at every Russian region. The issues of modern unification of a
school space will be considered in the future research.
Developing Geo-Information System of Accessible Tourism for People with Disabilities
Authors: Gura D A , Gribkova I S , Lesovaya E D , Kiryunikova N M , Solodunov A A
Published: March 2021

Nowadays, special attention is paid to people with disabilities in the Russian Federation. More than 12 million people with disabilities live in Russia. The issue of transportation and accommodation of reduced mobility people is relevant. Due to that, a geo-information accessible tourism system for people with disabilities is suggested. It will be used to solve several relevant issues — transportation of such category of people, the active recreation and accessible tourism organization. There are two main problems of transportation of people with disabilities: the first issue relates to the physical unavailability of social infrastructure sites, the second issue is the absence of information about these sites for this category of citizens. The article describes the option to solve the issues mentioned above. This paper describes sports adapted for people with disabilities and advantages to use geo-information systems. The authors suggest the algorithms for making up a geo-information system for this category of people on the territory of the Russian Federation.
Computer Simulation of Electric Curing of In-Situ Reinforced Concrete Structures
Authors: Gnyrya A I , Korobkov S V , Vodnev B S
Published: March 2021

The paper presents the results of computer simulation of electric curing of in-situ reinforced concrete columns using the ELCUT Pro 6. 3 software. The purpose of this work is to solve the thermodynamic problem of electric curing under freezing temperatures. A block of a monolithic residence building under construction (Tomsk, Russia) is assumed as a basis. The importance of this research arises from the need to provide the temperature conditions for concrete curing and strength gain in winter. The initial parameters are introduced in the ELCUT Pro with the WinConcret add-in for the built structures. As a result, the rod electrode spacing is determined to provide a uniform distribution of temperature fields over the structure cross-section. The time of isothermal concrete heating and the concrete strength are identified depending on the outside temperature. Rationale is prepared for the mold heat insulation for in-situ reinforced concrete columns, depending on the outside temperature. Based on the ELCUT Pro simulation, the electric curing technique is proposed for reinforced concrete columns at freezing temperatures. This technique is deployed in on-site conditions.
Influence of the Porous Structure of a Cement Substrate on the Stress State of Coatings
Authors: Loganina V I
Published: March 2021

The article presents the results of a study of the effect of pores, unfilled with a paint composition, on cracking of paint coatings. A model for calculating stresses is presented. The effect of the discrete nature of the contact of the coating with the substrate on the distribution of internal stresses in the coating is established. The effect of the pore size on the substrate and the coating thickness on the values of internal stresses is shown. It was found that in the absence of cracking in the coating, the dependence of the stress on the pore diameter in the contact zone is practically not manifested. It is shown that at a coating thickness of more than 0.09 cm, the relative deformations of the coating exceed the value of the ultimate elongation, cracking is predicted. The stress values in the coating above the pore not filled with the paint composition are constant. For the area of dense abutment of the coating, the dependence of the stress value on the pore diameter is observed.
Strength and Rigidity of Modified Epoxy Composites Under Static Loading
Authors: Gavrilov M A , Martynov A A , Filatov A V
Published: March 2021

The creation of building materials and products with improved properties, increased efficiency, contribution to a decrease in material consumption, cost and ease of manufacturing, is one of the most important tasks in the field of production of building materials. The use of modifying components in the manufacture of polymer composites is one of the main methods for improving their physical and mechanical properties. Plasticizers, finely dispersed fillers and other components are used as modifying additives. During the following studies, organosilicon varnish and asbestos-containing waste from construction and chemical industries were used as modifiers. New materials have been developed on the basis of modified epoxy binders, including those made by compression and vibrocompression with the use of waste, which are distinguished by high physical, mechanical and operational properties. Such materials expand the raw material base for the manufacture of new compositions, protective polymer coatings and polymer concretes.
Classicism in Saratov’s Later 19th Century Architecture
Authors: Negulyaeva T V , Dyadchenko S F
Published: March 2021

Classicism is one of the most persistent architectural styles, as other styles successfully adopt its dogmas. This paper dwells upon how classicist trends influenced the successor style: eclecticism. The research builds upon studying Saratov’s architectural monuments built in the second half of the 19th century to compare their core features to those of classical architecture. In conclusion, the paper analyzes how classicism affected the architectural eclecticism and attempts to define the most persistent principles behind architecture and how it comes into being.
Study of Quality Parameters of Long-Term Strength of Cement Composites
Authors: Maksimova I N , Makridin N I , Dergunova A V , Barabanov D N
Published: March 2021

The currently widespread assessment of concrete quality, including reliability, by traditional mechanical characteristics is ineffective, since these state parameters do not take into account changes in the strength and deformation properties of concrete under the influence of temporary processes of microcracking during loading when diagnosing structural materials. Modern development of fracture mechanics has made it possible to establish scientific principles for evaluating materials and testing methods and to propose together force, strain, energy and acoustic criteria for crack resistance that determine the actual limit States of their structure in terms of strength and deformability and thus allow predicting the performance of the material under load. This paper presents the results of experimental evaluation of mechanical failure criteria and regularities of changes in acoustic emission parameters from the loading intensity during non-equilibrium mechanical tests for three-point bending of experimental samples with an initial incision depth of 13 mm. Analysis of the influence of the concentration and the introduction of SP-3 on regularities of changes in the coefficients of increase of controlled criteria of crack resistance in time relative to 28-day age quite clearly suggests, first, that the change of parameters of criteria of crack resistance in time has a wavelike nature, and the change in strength under axial compression, and, secondly, about, that the modified structures of cement stone samples relative to the control composition generally give significantly better indicators not only of the growth coefficients of the compared quality criteria, but also of the absolute values of the criteria for crack resistance up to 18 years of age.
Characteristic Properties of Surface Run-off and Its Disposal from Railway Transport Enterprises
Authors: Strelkov A K , Teplykh S Yu
Published: March 2021

This paper focuses on railway transport enterprises and their classification. It outlines the number of railway stations of the Kuibyshev railway (KZhD) located in various regions of this country. The classification takes into account the region where these railway stations are located, the number of tracks at every particular station, and its land area. The article provides data on the surveyed railway transport enterprises and information on surface wastewater generated on their territory. The researchers analyze surface run-off from various railway industry enterprises, this wastewater composition and the dependence of contamination of surface wastewater discharged by different railway industry enterprises on the form and composition of their watersheds. They come up with recommendations for criteria of surface wastewater disposal from the territories of railway transport enterprises and railway tracks, as well as proposals for the treatment of surface run-off from the enterprises under consideration.
Nutrient Metabolism of Young Cattle in the Conditions of Yakutia When Non-Traditional Feed Additives are Included in Their Rations
Authors: Grigorev M F , Grigoreva A I , Popova A V
Published: March 2021

The work is aimed to develop innovative ways to increase effectiveness of a process of acclimatization and adaptation of the Hereford breed youngsters of Siberian selection, to increase its beef productivity, to enhance its usage of nutrient materials in the diet through inclusion to the diet of animals the local mineral feed supplements (Hongurin’s zeolite and putrid mud) with mineral salt that compensate a deficit of mineral materials in the diet. The number of hemoglobin was larger in the experimental groups of animals than in the control group of bull-calves, which demonstrates better metabolic processes. Balance of nitrogen, calcium, and phosphorus in every studied group was positive. High rates of the usage of nitrogen, calcium, and phosphorus, from taken to digested, were in the first and the second experimental groups of bull-calves. The usage of the local mineral feed supplements in the Hereford breed bull-calves’ diet provided increasing in their digestibility of nutrient materials, such as, in average, crude protein by 2,63 and 2,78%, crude fat by 2,32 and 3,24%, crude fiber by 1,77 and 3,27%, nitrogen-free extractable substances by 5,12 and 8,40%. Higher indicators of fixed nitrogen, calcium, and phosphorus from taken to digested were in the first and the second experimental groups of bull-calves. Results of the experiment established relevance and effectiveness of the inclusion in the diet the local mineral feed supplements for the Hereford breed bull-calves.
Physiological Characteristics of Young Cattle in Central Yakutia When Using Local Non-Traditional Feed Additives in Their Rations
Authors: Grigoreva A I , Grigorev M F , Sysolyatina V V
Published: March 2021

Results of conducted experimental research on studying of the influence of the local mineral feed supplements on growth, development and physiological indicators of the Hereford breed bull-calves allow making the next conclusions: Feeding of the local mineral feed supplements to the Hereford breed bull-calves allow increasing gaining in live body weight by 7,79 and 11,17%. Live body weight at the age of 15 months was amounted to 328,3-345,2 kg with daily average weight gaining at the entirety of the period of the experiment of 705,7-784,5 g. The usage of the local mineral feed supplements in feeding of the Hereford breed youngsters contributed to more intensive growth and development. In the background of the usage of the local mineral feed supplements in the diet of the experimental groups it was established that elevated concentration of hemoglobin in blood and all physiological indicators were within established normal limits. Increasing of productiveness in the experimental groups of animals was accompanied by reliable changes to the side of normalization of biochemical indicators of blood. Therefore, inclusion of the local natural mineral feed supplements to the diet provides increasing of beef productivity of the Hereford breed bull-calves and increases economical effectiveness of their breeding and fattening.
Complex Assessment of Marine Traffic Safety
Authors: Grinyak V M , Devyatisilnyi A S , Ivanenko Y S
Published: March 2021

The paper is devoted to the problem of ensuring the safe movement of ships. The problem of assessing the safety of a traffic pattern implemented in a specific water area is considered. Five different safety metrics are introduced. The first metric - “traffic intensity” - the traditionally used traffic density estimate, is calculated as the number of vessels passing through a particular section of the water area per unit time. It is supplemented by the metrics “intensity and speed” (second) and “intensity and size of ships” (third). When calculating them, respectively, the speed of the vessels and their length, which determine the “weight” of each vessel, are taken into account. The fourth metric - “stability of traffic parameters” - takes into account the nature of the movement of ships in terms of the regularity of their courses and speeds. The paper discusses various options for the metric, to illustrate the simplest of them is implemented - an estimate of the standard deviation of the ship’s course. The fifth metric - “traffic saturation” - characterizes the density of movement of ships in terms of the possibility of their maneuvers. The metric appeals to the traditional model representations of the collective motion parameters of the vessels in the form of a “speed-course” diagram and makes it possible to indirectly assess the difficulty of decision-making by skippers and the emotional burden on traffic participants. In the discussion of the results of the work, the option of integrating the five proposed metrics in the form of a system of rules giving an integrated assessment of traffic safety in a particular section of the water area is considered. The work is accompanied by the results of calculations of the proposed metrics on real data on the movement of ships in the Tsugaru Strait and their discussion. It is shown that the proposed system of metrics allows you to create a systematic idea of the degree of danger of traffic implemented in the water area.
The Problem of Clustering Countries of the World on the Geopolitical Data
Authors: Smirnov I A , Malafeyev O A , Smirnova T E , Yakovets Yu V , Strekopytov S A
Published: March 2021

This article deals with the problem of clustering countries by a specific set of geo-political features, including demographic, geographical, economic, and other data. The K-means method was chosen as the clustering algorithm. This clustering allows us to identify the specifics and important trends in the development of the current geopolitical situation.
Consequences of Industrial Mineral Processing in the Arctic Zone of Yakutia
Authors: Moskvitin S
Published: March 2021

The Arctic zone of Yakutia is the industrially developed territory of the Republic. Processing of tin, rare earths and gold deposits for decades has led to formation of a huge mass of waste in the form of dumps and tailings. In the area tailing dumps of Batagai, Deputatskiy and Kularsky processing plants can be found nowadays, where ore tailings were dumped.

In this work mineralogical compositions of mining wastes are presented, and the structure and condition of the tailings dumps at present time are studied. The impact of actually applied technologies on the environmental situation in extracting tin, gold and rare earth minerals as well as mechanisms are examined. The impact of weathering processes on the environmental safety of the region was established.

As a result of the study, it was concluded that the tailings dumps pose a real ecological threat to the environment. In case of any accident, there will be consequences causing irreparable damage not only to the ecology of The Yana and Indigirka river basins, but also to the water area of the entire continental shelf of the North-East of Yakutia. Elimination of environmentally hazardous substances through industrial processing will reduce the risk of environmental threats to the territory and the entire Arctic basin.
Filtration Regimes Calculation of Hydraulic Structures of Alma Reservoir
Authors: Ivankova T , Volosukhin V , Fesenko L
Published: March 2021

In the article the Crimean Peninsula is exposed as one of the most problematic areas for providing water resources in the Russian Federation. By 2013, the filling of drinking-water reservoirs due to river runoff and precipitation was at the level of 20-25% of the total design volume and it was the lowest indicator for the last 25 years. In 2014, after the reunification of Crimea with Russia, new hydraulic structures began functioning to supply water to Crimean residents, which allowed filling the North Crimean Canal with water from the Belogorsky and Taigan reservoirs along the Biyuk-Karasu riverbed and eastern Crimea residents began to receive water. The average population density of Crimea is 85 people / km2. The average long-term value of water resources for this territory is 1.0 km3 / year, and one resident - 432 m3 / year, which is the lowest of all the constituent entities of the Russian Federation. Much attention is paid to the safety of operating reservoirs, including the oldest one in Crimea - Alminsky reservoir. The calculations are given and filtration strength of the dam body soils of reservoir is estimated: specific filtration flow rates, filtration flow outlet velocity and effective pressure gradients. Calculation of the filtration regimes of the dam construction was carried out for two loading cases: main and special load combination. The obtained data indicates that actual parameters of the dam construction provide filtration strength and structure reliability under the accepted loading cases.
Transport System of Northern and Arctic Regions: Assessment and Development Problems
Authors: Tsukerman V A , Goryachevskaya E S
Published: March 2021

The analysis of the current state and assessment of the transport system development of the regions of the North and the Arctic was carried out. Analysis of the transport system development on the example of the regions directly bordering with the Northern Sea Route was carried out: Arkhangelsk Region, Murmansk Region, Nenets Autonomous District, Yamalo-Nenets Autonomous District, Krasnoyarsk Territory, Republic of Sakha (Yakutia), Chukotka Autonomous District, Kamchatka Teerritory, Magadan Region, Sakhalin Region, Primorye Territory. It is shown that the northern and arctic regions are far behind in the development of the transport industry of the subarctic countries. Primorye Territory has the best values of density of general-purpose railways and highways as well as investments in development of transport compared to other regions and is characterized by maximum level of the transport system development during the analyzed period. Of the northern regions minimal values of the transport system development have Magadan Region and Nenets Autonomous District characterized by poor development of transport communications. It is needed a further research in direction of scientific and technological substantiation of the strategic development directions of the transport system of the North and the Arctic.
Integrated Transport Systems in Terminal Clusters of the Russian Far East
Authors: Shirokorad O , Arkhipov S , Volodkin P
Published: March 2021

The transport system plays a huge role in the life of a country or region. From it directly depends on the mobility of the population, its standard of living and socialization, economic development of the subject. At this article represents a study of existing route networks and the transport system of the Russian Far East, as well as a project to improve the routing system through the organization of the terminal terminal centre. However, discusses the current state of the transport system of the Far East, as well as proposed measures for its future development.
Pre-Fractionation as a Way to Improve the Efficiency of Grain-Cleaning Systems
Authors: Ovchinnikov D N , Ovchinnikova Yu I , Pozdnyakova N A
Published: March 2021

In most ordinary farms, the seed production share in the structure of the post-harvest processing and storage cost reaches 40 %, which is largely determined by the low productivity and operating quality of grain cleaners of existing grain-cleaning units. In farms, the required quality is achieved by repeatedly passing seed through grain cleaners, which leads to increased production costs, losses, and seed damage. Designing grain-cleaning lines based on the conventional flow sheet construction principles does not allow reducing the seed material damage and the production cost and leads to the cost of units increasing almost directly proportional to their productivity.

One way to solve the issue of improving the grain-cleaning system efficiency while reducing material and labor costs is the development and implementation of the grain mixture pre-fractionation technology based on the physical and mechanical characteristics of particles. Fractionation on an inclined plane with a curved surface (trampoline) increases the efficiency of grain cleaners by 20–30 % due to obtaining fractions of different quality before further processing.
Study of Meltwater Treatment Using the Industrial Waste and Natural Sorbents
Authors: Voronov A , Malyshkina E , Maksimova S
Published: March 2021

In winter, a huge amount of snow contains the specific pollutants (anti-icing reagents, oil products, ion-metals and others) accumulates in the cities of the Northern Russian Regions. The special environmental requirements for operation and engineering equipment of the snow-landfills are not excited. In this case, the soil cover and nearby water bodies are contaminated by meltwater, and the engineering and geological conditions are changing at these areas. The specific composition of the snow masses requires the use of the special treatment methods to remove such major contaminants as oil products and chlorides. Currently, an effective and relatively cheap sorption material for the extraction of these pollutants from meltwater is being actively sought. In this paper, the sorption properties of the industrial waste (sawdust) and natural sorbents (kaolin, clay) were studied. The best results for the meltwater treatment from oil products and chlorides with kaolin were obtained. The sorption filter design, which is part of the proposed technological scheme for the meltwater treatment, has developed.
Road Safety Status Monitoring and Evaluation
Authors: Klyavin V , Baryshev N , Dvurechenskaya A , Zelikov V
Published: March 2021

Prevention of road traffic injuries requires a strong awareness of the situation on roads. The main sources of information on road safety are state statistics, sociological and observational studies. Observational studies or monitoring are among the most effective ways of obtaining information. The implementation of the RS-10 international project in Russia demonstrated the importance of all sources of information working jointly, which made it possible to develop effective actions on reducing road traffic injuries, to implement the actions and to evaluate the results.
Level Increase of Process Safety Culture at the Fuel and Energy Complex Enterprises
Authors: Glebova E V , Volokhina A T , Vikhrov A E , Chistyakova N D
Published: March 2021

The priority development area, according the Russian Federation state policy framework in the field of industrial safety till 2025, is the high process safety formation, ensuring maximum employees involvement and their direct participation in safety issues, as well as the development of behavioral safety audit (BSA) skills. As a result of the studies, development of the safety culture level at the one of the gas transmission enterprises was assessed. The assessment was based on the results of two surveys. The first survey was carried out to assess the current level of safety culture before the BSA procedure implementation in the company, while the second one was conducted after the regular BSA procedure performing during two quarters of 2019. Using mathematical data processing, the statistical significance of variance in safety culture components assessments revealed was proved for professional group: production workers. At the same time, there were no changes identified for professional groups: specialists and executives. Using cluster analysis, the characteristics of the obtained culture levels were determined. The cluster analysis also revealed the increase in the number of production workers who rated the safety culture at the high level. Such results indicate the successful implementation of the BSA procedure in a company.
Forecasting the Effectiveness of Well Performance Improvement Techniques
Authors: Gabdrakhmanova K F , Izmailova G R , Samigullina L Z
Published: March 2021

The article discusses the Pearson criterion method to determine the effectiveness of the chemical methods of the bottomhole formation zone treatment, the well zone and further improvement of the corresponding methods. Despite the rather high efficiency of the physicochemical methods used to increase oil recovery in the Shirotniy Ob area, ongoing geological and technical measures do not always ensure the optimal volumes of additional oil production achievement. Because of the bottom-hole formation zone treatments, an increase in the wells production rate was obtained. However, there are wells in which, after applying the enhanced oil recovery (EOR) techniques, the well production rates not only did not increase, but, moreover, their decrease and increase in water cut were noted. The increase in well flow rates after treatments varies widely; the effect duration is also different. The study of the effectiveness of the bottomhole formation treatment jobs organization modeling calls for a fundamentally new formulation and new methodological solutions. It should be carried out taking into account the economic feasibility of various forms and methods of work organizing, providing for maintenance based on analysis and geological field material processing by means of mathematical methods and computer technology. In this regard, the a systematic approach methodology application for analyzing and regulating the effectiveness of physicochemical methods of oil recovery enhancing at a late stage of oil field development is an urgent task and involves the creation of models that can significantly increase the of reliability of the justification and work organization for the use of progressive wells formation treatment techniques.
Patterns of Composite Soils Behavior under Shear and Compression
Authors: Dobud’ko O V , Aminova L I
Published: March 2021

Clastic-silty-clayed (composite) soils of natural and artificial composition are the most widespread on construction sites in the Russian Far East, which makes the study of their strength and deformation properties relevant. Based on the results of laboratory and field studies, the relationship between the macrostructure and physical parameters of composite soil constituents and their mechanical properties was analyzed, and substantiation of patterns of composite soils behavior under shear and compression was made.
Quality of Translucent Building Structures: Control Technologies
Authors: Baurina S B , Nazarova E V
Published: March 2021

This article is devoted to research of technologies of control and quality assurance of building structures. The object of the study is translucent structures. Indicators of quality and consumer properties of translucent structures are specified. Characteristics of methods of quality control and assurance are given. The technology of input quality control of raw materials and materials during production of translucent structures is analyzed in detail. The procedure for operational production control of translucent structures is defined. Features of acceptance quality control of finished products are revealed.
Efficient particle collection using concentric optical ring array
Authors: Wang Lin , Cao Yongyin , Zhang Yanxia , Shi Bojian , Li Hang , Feng Rui , Sun Fangkui , Ding Weiqiang
Published: March 2021

Trapping is the first as well as the most important step in various optical manipulations. However, when the concentration of sample is extremely low, optical trapping cannot be performed efficiently because the samples are usually out of the action radius of the trapping well. In this paper, numerical simulation results are presented to illustrate an active and efficient optical collection mechanism. We propose the optical collection mechanism by using an array of concentric dielectric rings, in which a series of nanoholes are introduced with optimized separations and radius to form trapping centers. When the incident wavelength is tuned in order, the trapped particles will be transferred from an outer ring to its inner neighboring ring, and finally be collected to the center of the rings. The mechanism reported here paves the way for efficient particle collection, and may find potential applications in various optical manipulations.
Photovoltaic properties of metal-free semiconductor DMEDA·I6: A first-principles investigation
Authors: Liu Fuxiang , Xu Peng
Published: March 2021

Metal-free halide materials have garnered significant attention. However, because of their large band gap, current metal-free materials are not suitable as solar cell absorbers. A metal-free semiconductor, DMEDA·I6, with a narrow band gap (∼1.36 eV) and strong light absorption, is a promising candidate for solar cell absorbers. Using the first-principles calculation method, a systematic investigation was conducted on the photovoltaic properties of DMEDA·I6, including electronic properties, variation trend of the band gap under strain, defect physics, and band alignments of solar cell interfaces. It was found that DMEDA·I6 crystallized in a one-dimensional I chain with alternating long and short I–I bond lengths. Although both the valence band maximum and conduction band minimum of DMEDA·I6 are derived from the I p states, their compositions are distinguishable owing to the abnormal I–I bond arrangement. The band gap of DMEDA·I6 increases when the lattice volume expands, which is similar to that of the popular lead-based perovskites and opposite to that of the conventional zincblende semiconductors. Among the intrinsic defects, only defect VI can produce a deep defect level in the band gap. The formation of VI can be suppressed under the I-rich preparation conditions; thus, I rich condition is proposed when preparing DMEDA·I6 solar cell absorbers. Commonly used hole transportation materials are suitable for DMEDA·I6-based solar cells, whereas electron transport materials (ETMs) with a lower lowest unoccupied molecular orbital than commonly used ETMs should be used.
Multifunctional polydopamine-based nanoparticles: synthesis, physico-chemical properties and applications for bimodal photothermal/photodynamic therapy of cancer
Authors: Zmerli Islam , Michel Jean-Philippe , Makky Ali
Published: March 2021

Polydopamine (PDA) is a mussel-inspired and a melanin-mimicking material that has attracted considerable attention during the recent years. This ‘polymer’ displays diverse promising properties, like its simple preparation procedures, easy functionalization, free radicals scavenging activity, outstanding photothermal and photoacoustic performance, and its great biocompatibility and biodegradability. A remarkable feature of PDA is its ability to form colloidal nanosized particles or nanoscaled coatings, allowing the preparation of various nanoparticulate structures. The first studies into PDA mainly explored the polymerization mechanisms of this material and the development of controlled preparation protocols. Later works focused on the investigation of these nanomaterials for the design and development of multifunctional platforms and their implementation in multiple biomedical fields, particularly in cancer treatment and bio-imaging. The purpose of this review is to (a) give a detailed overview about the synthesis methods of PDA and the formation mechanisms proposed so far in the literature, (b) outline the remarkable physico-chemical and functional properties of PDA nanomaterials, and (c) summarize the application of PDA-derived nanosystems in cancer theranostics and particularly in drug delivery and light-mediated cancer therapy with a special emphasis on the different strategies that can be used for the design of smart nanosystems with bimodal photothermal/photodynamic properties. Finally, a comparison of physicochemical properties and biomedical applications between PDA and other catecholamine derivatives is made.
Improving epidemic testing and containment strategies using machine learning
Authors: Natali Laura , Helgadottir Saga , Maragò Onofrio M , Volpe Giovanni
Published: March 2021

Containment of epidemic outbreaks entails great societal and economic costs. Cost-effective containment strategies rely on efficiently identifying infected individuals, making the best possible use of the available testing resources. Therefore, quickly identifying the optimal testing strategy is of critical importance. Here, we demonstrate that machine learning can be used to identify which individuals are most beneficial to test, automatically and dynamically adapting the testing strategy to the characteristics of the disease outbreak. Specifically, we simulate an outbreak using the archetypal susceptible-infectious-recovered (SIR) model and we use data about the first confirmed cases to train a neural network that learns to make predictions about the rest of the population. Using these predictions, we manage to contain the outbreak more effectively and more quickly than with standard approaches. Furthermore, we demonstrate how this method can be used also when there is a possibility of reinfection (SIRS model) to efficiently eradicate an endemic disease.
Evaluation of a High-Definition PCR Assay for the Detection of SARS-CoV-2 in Extracted and Nonextracted Respiratory Specimens Collected in Various Transport Media
Authors: Buchan Blake W , Gerstbrein Derek , Cruz Amorina , Hoff Jess , Sievert Emily , Ledeboer Nathan A , Faron Matthew L
Published: March 2021

Objectives

We conducted an analytic and clinical comparison of a novel high-definition polymerase chain reaction PCR (HDPCR) assay to traditional real-time PCR (RT-PCR) for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in upper respiratory specimens.

Methods

Analytic performance of RT-PCR, HDPCR, and extraction-free HDPCR was established through replicate testing of a serially diluted clinical specimen containing SARS-CoV-2. A clinical comparison of all 3 assays was conducted using 351 prospectively collected upper respiratory swab specimens obtained from symptomatic and asymptomatic individuals collected in various transport media.

Results

RT-PCR and HDPCR assays using extracted nucleic acid demonstrated similar analytic limits of detection (LoD) and clinical performance, with 100% positive and negative agreement. Extraction-free HDPCR demonstrated a 1.5 to 2.0 log10 increase in LoD based on cycle threshold values. However, clinical performance of extraction-free HDPCR remained high, demonstrating 97.8% positive and 99.6% negative agreement with RT-PCR. An overall increase in “invalid” and “presumptive” results was observed when using the extraction-free method, but this was highly variable based on transport medium used.

Conclusions

HDPCR performs similar to RT-PCR for the detection of SARS-CoV-2. The use of an extraction-free HDPCR protocol maintained high clinical performance despite reduced analytic LoD, with the benefit of reduced hands-on time and cost of reagents associated with nucleic acid extraction.
Validation of the Coin in Hand-Extended Version Among Older Adults With and Without Dementia
Authors: Ferreira Inês , Fernandes Sandra , Querido Luís , Pires Rute , Daugherty Julia C , Hidalgo-Ruzzante Natalia , Pérez-García Miguel
Published: March 2021

Objective

The current study aimed to validate the Performance Validity Test Coin in Hand-Extended Version (CIH-EV) in groups of healthy older adults and older adults with dementia.

Method

Using an analog simulation paradigm, the healthy control group and the clinical group were instructed to perform to the best of their ability, whereas the feigning older adults were instructed to simulate a memory deficit to obtain allowance, financial aid, or early retirement.

Results

Results showed that the control and clinical groups performed more optimally than the feigning group, although the clinical group had superior response times. The CIH-EV was insensitive to sociodemographic variables and neurocognitive functioning in all groups, demonstrated good convergent validity with other performance validity measures, and showed a reduced rate of false positives.

Conclusions

This study corroborates the CIH-EV’s effectiveness in detecting the simulation of cognitive deficits in healthy older adults and older adults with dementia.
TALE: Transformer-based protein function Annotation with joint sequence–Label Embedding
Authors: Cao Yue , Shen Yang
Published: March 2021

Motivation

Facing the increasing gap between high-throughput sequence data and limited functional insights, computational protein function annotation provides a high-throughput alternative to experimental approaches. However, current methods can have limited applicability while relying on protein data besides sequences, or lack generalizability to novel sequences, species and functions.

Results

To overcome aforementioned barriers in applicability and generalizability, we propose a novel deep learning model using only sequence information for proteins, named Transformer-based protein function Annotation through joint sequence–Label Embedding (TALE). For generalizability to novel sequences we use self-attention-based transformers to capture global patterns in sequences. For generalizability to unseen or rarely seen functions (tail labels), we embed protein function labels (hierarchical GO terms on directed graphs) together with inputs/features (1D sequences) in a joint latent space. Combining TALE and a sequence similarity-based method, TALE+ outperformed competing methods when only sequence input is available. It even outperformed a state-of-the-art method using network information besides sequence, in two of the three gene ontologies. Furthermore, TALE and TALE+ showed superior generalizability to proteins of low similarity, new species, or rarely annotated functions compared to training data, revealing deep insights into the protein sequence–function relationship. Ablation studies elucidated contributions of algorithmic components toward the accuracy and the generalizability; and a GO term-centric analysis was also provided.

Availability and implementation

The data, source codes and models are available at https://github.com/Shen-Lab/TALE.

Supplementary information

Supplementary data are available at Bioinformatics online.
Incorporating Biogeochemistry into Dryland Restoration
Authors: Young Kristina E , Reed Sasha C , Ferrenberg Scott , Faist Akasha , Winkler Daniel E , Cort Catherine , Darrouzet-Nardi Anthony
Published: March 2021

Dryland degradation is a persistent and accelerating global problem. Although the mechanisms initiating and maintaining dryland degradation are largely understood, returning productivity and function through ecological restoration remains difficult. Water limitation commonly drives slow recovery rates within drylands; however, the altered biogeochemical cycles that accompany degradation also play key roles in limiting restoration outcomes. Addressing biogeochemical changes and resource limitations may help improve restoration efforts within this difficult-to-restore biome. In the present article, we present a synthesis of restoration literature that identifies multiple ways biogeochemical understandings might augment dryland restoration outcomes, including timing restoration around resource cycling and uptake, connecting heterogeneous landscapes, manipulating resource pools, and using organismal functional traits to a restoration advantage. We conclude by suggesting ways to incorporate biogeochemistry into existing restoration frameworks and discuss research directions that may help improve restoration outcomes in the world's highly altered dryland landscapes.
Outcome of microscopically non-radical oesophagectomy for oesophageal and oesophagogastric junctional cancer: nationwide cohort study
Authors: Hollertz P , Lindblad M , Sandström P , Halldestam I , Edholm D
Published: March 2021

Background

Microscopically non-radical (R1) oesophageal cancer resection has been associated with worse survival. The aim of this study was to identify risk factors for R1 resection and to investigate how this affects long-term survival.

Methods

The Swedish National Register for Oesophageal and Gastric Cancer was used to identify all patients who underwent oesophageal cancer resection with curative intent between 2006 and 2017. Risk factors for R1 resection were assessed by multivariable logistic regression analysis, and factors predicting 5-year survival identified by multivariable Cox regression.

Results

The study included 1460 patients. Surgical margins were involved microscopically in 142 patients (9.7 per cent). The circumferential resection margin was involved in 114 (7.8 per cent), the proximal margin in 53 (3.6 per cent), and the distal margin in 29 (2.0 per cent). In 30 specimens (2.1 per cent), two or all three margins were involved. Independent risk factors for R1 resection were male sex, low BMI, absence of neoadjuvant treatments, and clinical T4 disease. The 5-year survival rate for the entire cohort was 42.2 per cent, but only 18.0 per cent for those who had an R1 resection. Independent risk factors for death within 5 years of resection were male sex, age above 60 years, normal BMI, ASA fitness grade III, intermediate-level education, R1 resection (hazard ratio 1.80, 95 per cent c.i. 1.40 to 2.32), clinical T3 disease, and clinical lymph node metastasis.

Conclusion

R1 resection is common and predicts poor 5-year survival. Absence of neoadjuvant treatment is a risk factor for R1 resection.
Elucidating autoimmune nodopathies and the CIDP spectrum
Authors: van Doorn Pieter A , Hadden Robert D M , Van den Bergh Peter Y K
Published: March 2021

This scientific commentary refers to ‘Antibodies to the Caspr1/contactin-1 complex in chronic inflammatory demyelinating polyradiculoneuropathy’, by Pascual-Goñi et al. (doi:10.1093/brain/awab014).