bluuebunny/crossref_metadata_2025 huggingface dataset:
A high-performance potassium metal battery using safe ionic liquid electrolyte
Authors: Sun Hao , Liang Peng , Zhu Guanzhou , Hung Wei Hsuan , Li Yuan-Yao , Tai Hung-Chun , Huang Cheng-Liang , Li Jiachen , Meng Yongtao , Angell Michael , Wang Chang-An , Dai Hongjie
Published: October 2020

Significance

Rechargeable potassium batteries are promising alternatives of Li batteries owing to the earth abundance and low cost of potassium. The safety of K metal battery involving highly reactive potassium metal and flammable organic electrolyte remains poor, risking fire hazards during use. This work presents the development of an ionic liquid electrolyte that allows safe and high-performance potassium metal batteries. An impressive capacity retention of 89% after 820 cycles is achieved with a high average Coulombic efficiency of 99.9%. Moreover, the K metal battery can safely and stably work at 60 °C. This work provides insights to future design and innovation of other metal batteries toward safe and long-life energy storage.
Elucidating aromatic acid tolerance at low pH in
Saccharomyces cerevisiae
using adaptive laboratory evolution
Authors: Pereira Rui , Mohamed Elsayed T. , Radi Mohammad S. , Herrgård Markus J. , Feist Adam M. , Nielsen Jens , Chen Yun
Published: October 2020

Significance

Understanding the tolerance mechanism to inhibiting chemicals can help in the design of more robust microbial strains for use in industrial bioprocesses. Aromatic acids are important bioactive molecules and precursors for many plant natural products. This study focused on analyzing
Saccharomyces cerevisiae
mutants tolerant to aromatic acids and revealed that regulating the transport of these compounds from the cytosol is the main mechanism to improve tolerance. Using this knowledge, the transport of aromatic acid can be fine tuned to improve the secretion of aromatic compounds and improve the robustness of yeast strains for industrial use.
Evidence for an effector-independent action system from people born without hands
Authors: Liu Yuqi , Vannuscorps Gilles , Caramazza Alfonso , Striem-Amit Ella
Published: October 2020

Significance

What are the principles of brain organization? In the motor domain, separate pathways were found for reaching and grasping actions performed by the hand. To what extent is this organization specific to the hand or based on abstract action types, regardless of which body part performs them? We tested people born without hands who perform actions with their feet. Activity in frontoparietal association motor areas showed preference for an action type (reaching or grasping), regardless of whether it was performed by the foot in people born without hands or by the hand in typically-developed controls. These findings provide evidence that some association areas are organized based on abstract functions of action types, independent of specific sensorimotor experience and parameters of specific body parts.
The influence of carbohydrate ingestion on peripheral and central fatigue during exercise in hypoxia: A narrative review
Authors: Paris Hunter L. , Sinai Erin C. , Shei Ren‐Jay , Keller Alexandra M. , Mickleborough Timothy D.
Published: October 2020

Hypoxia impairs aerobic performance by accelerating fatiguing processes. These processes may originate from sites either distal (peripheral) or proximal (central) to the neuromuscular junction, though these are not mutually exclusive. Peripheral mechanisms include decrements in muscle glycogen or fluctuations in intramuscular metabolites, whereas central responses commonly refer to reductions in central motor drive elicited by alterations in blood glucose and neurotransmitter concentrations as well as arterial hypoxemia. Hypoxia may accelerate both peripheral and central pathways of fatigue, with the level of hypoxia strongly dictating the degree and primary locus of impairment. As more people journey to hypoxic settings for work and recreation, developing strategies to improve work capacity in these environments becomes increasingly relevant. Given that sea level performance improves with nutritional interventions such as carbohydrate (CHO) ingestion, a similar strategy may prove effective in delaying fatigue in hypoxia, particularly considering how the metabolic pathways enhanced with CHO supplementation overlap the fatiguing pathways upregulated in hypoxia. Many questions regarding the relationship between CHO, hypoxia, and fatigue remain unanswered, including specifics on when to ingest, what to ingest, and how varying altitudes influence supplementation effectiveness. Therefore, the purpose of this narrative review is to examine the peripheral and central mechanisms contributing to fatigue during aerobic exercise at varying degrees of hypoxia and to assess the role of CHO ingestion in attenuating fatigue onset.
Finding key points in a hand image using heatmaps
Authors: Arslanova D V , Grishin A E , Denisov A I , Galimullin D Z , Denisova N V , Makarov R A , Sibgatullin M E
Published: October 2020

This paper presents an approach to finding key points in the image of a hand using heat maps. For this, a convolutional model of a neural network and a training method on heatmaps were combined. An open bank of palm photos, supplemented by a set of own images and synthetic data, was used as a dataset. Direct and inverse transformations of two-dimensional coordinates on the plane into heat maps with a 2D Gaussian function centered at coordinate points were applied, data was prepared, the model was trained and tested. As a result of this approach, a neural network model able to recognise real world images was obtained.
Nonperturbative renormalization of the interaction of quantum dots with the phonon reservoir
Authors: Kh Gainutdinov R , Nabieva L J , Garifullin A I , Mutygullina A A
Published: October 2020

The quantum dynamics of a single quantum dot with phonon reservoir is investigated by making use generalized quantum dynamics equation [Gainutdinov R.Kh. 1999 J. Phys. A 32 5675]. The self-energy function is calculated nonperturbatively taking into account the renormalization of the vertex function. In this paper, we show that the nonperturbative renormalization of the vertex function significantly affects the nature of the interaction of the quantum dot with the phonon reservoir.
Estimation of Internal Gearbox Loads for Condition Monitoring in Wind Turbines Based on Physical Modeling
Authors: Pagitsch M , Jacobs G , Bosse D , Duda T
Published: October 2020

The share of wind energy in the public electricity supply in Europe is constantly growing, so that reliability and availability of wind turbines are becoming increasingly important. High availability is ensured by continuous condition monitoring, because it allows long downtimes to be avoided by reacting immediately to (imminent) failures. This paper presents a portable and real-time capable simulation model for determining internal loads on components in the mechanical drivetrain. The loads are apt for being utilized for a subsequent generation of a system reliability index in the scope of a decision support tool for demand- and degradation-oriented adjustments of the operational management. Thus, the work contributes to ensuring reliability. By determining the state of degradation of similarly loaded plants, under- or overloading of individual turbines can be proactively prevented. The analysis of the influence of individual model parameters is of particular importance here and provides evidence that even with a restricted parameter set the outputs of the load calculation model are accurate enough as inputs for a reliability calculation.
Consequences of load mitigation control strategies for a floating wind turbine
Authors: Lee C F , Bachynski E E , Nejad A R
Published: October 2020

Several approaches to avoid control-induced resonances of floating wind turbines have been proposed. The main focus has been on reductions in global motions and loads in the tower base. In the present work, we examine the consequences of three such controllers on the loads on drivetrain components. One common advantage that comes along implementing all the alternative controller designs is an improved motion response in surge and pitch directions. However, these reductions come at other costs. Evaluating the drivetrain performance through multi-body simulations identifies new considerations for controller design. For example, tower top shear stress may not have been perceived as an important design criteria from a structural load perspective, but contributes to the radial load of bearings and gears and should be taken into consideration when comparing controller performance.
Statistic and Coherence Response of Ship-based Lidar Observations to Motion Compensation
Authors: Duscha Christiane , Paskyabi Mostafa Bakhoday , Reuder Joachim
Published: October 2020

Ship-based profiling Lidar systems experience a strong influence of rotational and translational motion on beam direction and hence the line-of-sight velocity. This motion error is inherited by the retrieved 3-dimensional wind vector and is especially visible in the velocity spectra and cross-spectra of velocities at different measurement heights (coherence). Applying motion compensation on the line-of-sight velocity observations was found to have a strong impact on the statistical properties of the retrieved wind vector and successfully improved the corresponding velocity distributions. The impact of motion correction on the spectra of the horizontal wind speed components was found to be neglectable. The Lidar measurement principle, in particular the effect of cross-contamination at higher frequencies, was found to have a larger impact in shaping the horizontal spectra than motion correction. Vertical velocity spectra were strongly affected by ship motion and the motion correction was only partly successful. Precisely, this effect was present at frequencies larger than the resonance frequency of the ship.
Experimental investigations on the fatigue resistance of automatically welded tubular X-joints for jacket support structures
Authors: Schürmann K , Schaumann P , Pittner A , Rethmeier M
Published: October 2020

The development within the offshore wind sector towards more powerful turbines combined with increasing water depth for new wind parks is challenging both the designer as well as the manufacturer of bottom fixed support structures. Besides XL-monopiles, the market developed an innovative and economic jacket support structure which is based on automatically manufactured tubular joints combined with standardized pipes. Besides the improvements for a serial manufacturing process the automatically welded tubular joints show a great potential in terms of fatigue resistance e.g. due to a smooth weld geometry without sharp notches. However, these benefits are not considered yet within the fatigue design process of automatically manufactured jacket substructures according to current standards due to the lack of suitable S-N curves. Therefore, 32 axial fatigue tests on single and double-sided automatically welded tubular X-joints have been performed to determine a new hot spot stress related S-N curve. Based on these constant amplitude fatigue tests a new S-N curve equal to a FAT 126 curve was computed which implicitly includes the benefits of the automatically welding procedure.
Fast divergence-conforming reduced basis methods for stationary and transient flow problems
Authors: Fonn E , van Brummelen H , Kvamsdal T , Rasheed A
Published: October 2020

Reduced basis methods (RB methods or RBMs) form one of the most promising techniques to deliver numerical solutions of parametrized PDEs in real-time with reasonable accuracy [1]. For the Navier-Stokes equation, RBMs based on stable velocity-pressure spaces do not generally inherit the stability of the high-fdelity method. Common techniques for working around this problem (e.g. [2]) have the effect of deteriorating the performance of the RBM in the performance-critical online stage.

We show how divergence-free reduced formulations eliminates this problem, producing RBMs that are faster by an order of magnitude or more in the online stage. This is most easily achieved using divergence-conforming compatible B-spline bases, using a transformation that can maintain the divergence-free property under variable geometries. See [3] for more details.

We also demonstrate the flexibility of RBMs for non-stationary flow problems using a problem with two stages: an initial, finite transient stage where the flow pattern settles from the initial data, followed by a terminal and infinite oscillatory stage characterized by vortex shedding. We show how an RBM whose data is only sourced from the terminal stage nevertheless can produce solutions that pass through the initial stage without critical problems (e.g. crashing, diverging or blowing up).
Pictorial techniques of Russia and China in environmental design
Authors: Xiaogeng Chang
Published: October 2020

Environmental design in Russia and China in academic terms refers to the field of education in the areas of art and culture, in methodological terms it is based on the methods and principles of fine art. The article presents a creative project of the photo exhibition “Dance of Leaves”, which was created by the author using techniques of Chinese traditional painting and Russian abstract art, in particular the ideas of V. V. Kandinsky. The project applied the method of integration of disciplines, for example, color science, cultural studies, engineering etc. A special feature of the photo exhibition was the presence of various lighting technologies, as well as the game of colors and lines with symbolic cultural connotation.
Energy efficiency improvement of aerated concrete block wall fences
Authors: Suleymanova Lyudmila , Pogorelova Inna , Suleymanov Karim
Published: October 2020

The development of effective protecting structures is currently one of the most popular areas in the construction industry. In order to ensure energy efficiency and environmental safety in the construction of civil buildings, masonry made of aerated concrete blocks with high thermal protection properties is used as protecting structures. As glue and cement-sand solutions in masonry have low thermal conductivity and are temperature bridges, the issue of filling through seams of aerated concrete masonry is very acute. The authors have developed a double row of concrete masonry, having a minimum number of cross-cutting horizontal seams, which not only improves thermal insulation properties, but also reduces material consumption and, consequently, the complexity of the arrangement of protecting structures of civil buildings. The influence of through horizontal seams made of cement-sand grout and block binding on the resistance to heat transfer of masonry made of aerated concrete blocks is considered.
Soundproofing materials in construction using polymer composites
Authors: Denisova L V , Klyuchnikova N V , Emelyanov S V
Published: October 2020

Today, obtaining products for recycling of polymer materials is of great interest, including for the construction industry. At the same time, not only new materials are created with the specified performance characteristics, but also the environmental problem is solved, nature is preserved and natural resources are saved. In this paper, it is proposed to use a fabric cord of used tires as a component of soundproofing material. Various types of latex were used as a binder: acrylic, natural, and styrene-butadiene. It was found that all the obtained composites have soundproofing properties. The best soundproofing properties are found in a material containing styrene-butadiene latex. Thus, it is shown that materials based on latex of various nature and textile products of tire processing can be used for soundproofing materials in the construction industry.
Lean construction – an effective management system in the construction industry
Authors: Parfenova E N , Avilova Zh N , Ganzha A N
Published: October 2020

The paper discusses the possibilities and prospects of using methods and tools of lean construction to improve the arragement of the construction business in the Belgorod region. Lean construction is considered as a system of innovative methods of process management in construction. The use of this system is an effective tool for optimizing the results of work: the time and cost of work is reduced by constantly improving the quality of the final product. Exploring the methodology and tools of lean construction, we can identify four main areas of use: employee engagement, cost reduction, optimization of construction processes, and loss prevention. The paper presents the results of using the concept of lean construction in foreign countries, as well as methods and tools aimed at involving employees in lean production, reducing costs and preventing losses, optimization, automation and informatization of the production process at the level of strategic and operational management. The specificity of the choice of tools and methods of work performed at all levels of management for the construction industry is determined. The application of the concept of lean construction is justified, which allows organizations to increase their competitiveness and business efficiency.
Development trend of the construction market in Russian regions
Authors: Lapteva E V , Ogorodnikova E P , Remizova V F
Published: October 2020

Construction in Russia is a dynamically developing type of economic activity. This is facilitated by various programs that support construction at both the municipal and federal levels. In the paper the method of economic-statistical analysis application of the construction market of the Orenburg region is formed, which will allow identifying patterns and factors influencing the development of the construction market of the Orenburg region, studying trends in the volume and structure of the construction market in order to identify promising directions of the construction market development in the region. As a result of applying methods of economic and statistical analysis (structure, dynamics and forecasting and factor analysis), structural and dynamic changes in the regional construction market are identified, trends in the dynamics of construction volume and factors affecting the growth rate (decline) of the construction market in the region are determined.
Research on parameters of the bladed pneumatic screw mechanism of the digging and transport machine
Authors: Kovalev A A , Kutuzov V V , Elkina I I
Published: October 2020

The main intensifiers that increase the efficiency of the bulldozer are considered. The concept of the digging and transport machine for bulk material is proposed, the design of which combines the positive qualities of pneumatic and bulldozer equipment. The machine is mainly intended for use in reclamation construction for filling holes, ravines, deep wells, filling the water-resistant layer of the bottom of a pond or reservoir, and also for supplying finely divided stone mining waste (sawdust, coal powder, limestone flour, carbonate sand, etc.) in the back of a dump truck or to the blade. The machine can also be used as auxiliary equipment and to fight a fire in the field by supplying a bulk fire-extinguishing agent directly to the edge of the flame front.
Using of automated risk assessment systems to ensure the safety of personnel at construction sites
Authors: Semeykin A Yu , Klimova E V , Nosatova E A , Khomchenko Yu V
Published: October 2020

The development of automated risk assessment systems is a promising area for scientific research in the field of OSH management. The paper analyses the main problems of the functioning of the OSH management system and identifies the need for its improvement in order to reduce occupational injuries. As a way to improve it, we propose the development and implementation of an automated system for forecasting and managing professional risks (AS FMPR), which implements an algorithm for multivariate analysis of the causes of occupational injuries. The stages of risk assessment are considered. The aim of this work is to assess the applicability of automated risk assessment systems to ensure the safety of personnel at construction sites. The results of the distribution of the probability of injury to workers depending on the factors studied are presented. This system will bring the procedure for assessing occupational risks in construction to a whole new level.
Experimental studies of obtaining biogas from waste of meat processing enterprises
Authors: Suslov D Y , Sedyh P S
Published: October 2020

A promising direction for the development of gas supply systems in rural areas is the production and use of biogas. In the developed countries of the world, biogas production and use systems are widely used. The amount of biogas produced depends on the type and chemical composition of the feedstock. The aim of this work is to study the dependence of the specific yield and chemical composition of biogas on the type of substrate used and the temperature of biomass in the digester. Waste from meat processing enterprises was used as an initial substrate for research: technical fat; intestines; bird blood; pulp. Two temperature settings were chosen for the study: 38 ° C and 42 ° C. As a result of the studies, the values of the optimal duration of fermentation of the studied types of substrate were determined: bird blood - 21 days, pulp - 25 days, intestines - 25 days, technical fat - 40 days. It has been established that the maximum value of the specific yield of biogas is observed during the fermentation of technical fat - 1509.8 l / kg, and the smallest of bird blood - 833.4 l / kg. At the same time, the highest methane content is observed during fermentation of technical fat - 66%, and the smallest from bird blood - 53.5%. It was also found that the biogas yield at a fermentation temperature of 42 ° C is 7-8% higher than the biogas yield obtained at a temperature of 38 ° C.
Influence of the composition of cement systems on the activity of modifying additives
Authors: Onoprienko N N , Salnickowa O N
Published: October 2020

Modifiers of cement systems with different compositions of functional groups of polymers were studied: carboxymethylcellulose, methylcellulose, polyvinyl alcohol, polyacrylamide. The results of studies of the influence of active ions on the viscosity of aqueous solutions of water-soluble polymers using viscometry methods are presented. The influence of the type and composition of functional groups of polymer additives on the resistance to calcium, sodium and potassium ions is analyzed. It is shown that in the presence of calcium, sodium or potassium ions in the liquid phase of cement solutions, it is possible to reduce the effectiveness of polymers as stabilizers of binding systems. The most resistant to electrolytes are polymers with dominated hydroxyl groups. The composition of functional groups of water-soluble polymers and the possibility of their interaction with various ions contained in cement, aggregate, filler, in the closing water, in the composition of soils have a decisive influence on the compatibility of the polymer and the binder, the properties of cement-polymer compositions. The principles of regulating the rheological and technological properties of cement-polymer compositions, deformations of dispersed systems by selecting the rational composition of the dispersed mixture, mineral and chemical additives are given. The regularities of compatibility of components of cement systems, mineral and chemical additives in order to increase the adhesion and strength characteristics of materials based on them in the development of compositions of masonry solutions, injection and other compositions for chemical fixing of soils, in individual housing construction, in order to carry out repair and restoration work to strengthen soil bases and stone structures are presented.
Processes of forming protective and decorative coatings on concrete at plasma treatment
Authors: Bondarenko N I , Bondarenko D O
Published: October 2020

The development and improvement of technologies for obtaining coatings on various composites using low-temperature plasma is very relevant today. The paper considers the possibility of using broken glass of colored container glasses and other sanitary construction ceramics to obtain protective and decorative coatings on concrete, the selection of the ratio of which will allow getting different tints of the melted layer. To expand the color and decorative characteristics of coatings, mixtures for powder and further compaction were developed. The results of research on plasma treatment of concrete with developed protective and decorative coatings based on broken glass of colored containers, special sanitary construction ceramics and alumina cement are presented. An organoleptic assessment of the quality of coatings after plasma treatment is given. The optimal fractional composition for obtaining protective and decorative coatings on concrete was identified and the optimal speed of plasma treatment of the front layer of the product was established. For practical use, the fraction of colored container glasses and sanitary construction ceramics 0.63-0.8 mm is recommended. By adjusting the speed of the plasma jet passing over the front surface of concrete, they can get a coating with various decorative and relief effects. It was found that at the plasma treatment speed of 10 mm/s a solid coating is formed, and at the plasma treatment speed of 25 mm/s a coating with a bumpy surface is formed.
Use of a supply ventilation system as an air curtain
Authors: Kireev V M , Alifanova A I , Ovsyannikov Yu G
Published: October 2020

Recently, for a number of reasons, retail and office premises on the first floors of the building, which have a separate entrance to the street, have gained wide popularity. These rooms must have supply ventilation to maintain the required microclimate parameters. The article proposes, in addition to fulfilling its main function, to use general exchange ventilation as an air curtain in these types of premises. Due to the supply of air above the doorway with certain parameters, in some cases, it is possible to abandon the thermal air curtain as a separate energy-intensive device. The implementation of this task is supposed to be carried out by organizing the necessary air exchange scheme, without increasing its required performance. The article presents the results of the study, which make it possible to assess the possibility of using the proposed technical solution for the most standard case. In particular, an adapted calculation of the air distribution grille is presented to fulfill the stated purpose.
Modifying additive for concrete based on shungite processing waste
Authors: Yestemessova A S , Altayeva Z N , Sarsenbayev B K , Budikova A M , Karshygayev R O
Published: October 2020

The paper is devoted to the study of waste processing of shungite rocks, which are formed in the process of mining and technological operations. However, the market of national modifying additives based on local raw materials is not developed at the appropriate level in the presence of a rich resource base of the mining industry. In this regard, it is of great interest to obtain additives based on shungite rock processing waste, which allow expanding the range of mineral additives and providing qualitatively new properties for concrete and reinforced concrete products and structures. Such technologies for the production of additives are isolated and not developed at the proper level due to insufficient knowledge of shungite rocks.

Analysis of the state of research on concrete and the market for modifying materials showed that the development of production of energy-efficient and environmentally friendly materials due to increasing regulatory requirements for them, as well as to environmental ecology and the obvious need to recycle industrial waste initiated the progressive development of concrete science. One of its latest achievements is modified concrete with special properties, which marked a new stage in the development of concrete. In its production technology, significant progress has been made in improving its chemical additives, special modifiers, as well as active and inactive fillers. In Kazakhstan, the main volume of modifying additives is imported from abroad, which significantly increases their cost, so their choice is limited.

This paper is devoted to the research of waste processing of shungite rocks as a modifying mineral additive of concrete. Its influence on the main indicators of concrete is investigated and the features of the processes that occur in the hardening silicate system “cement - dispersed shungite particles” and contribute to increasing the strength of concrete, as well as reducing the duration of its heat-and-water treatment are studied.
Using wastes of buckwheat processing as sorption materials for the removal of pollutants from aqueous media: a review
Authors: Shaikhiev I G , Sverguzova S V , Galimova R Z , Grechina A S
Published: October 2020

Based on data from various literature sources, information is given on the chemical composition of straw and husk of buckwheat grains. The information on buckwheat processing waste as a source for obtaining various valuable components is provided. Literature data on the use of ground buckwheat straw as a sorption material for the extraction of heavy metal ions and oil products from natural and sewage are presented. The possibility of increasing sorption characteristics by buckwheat straw treatment with various chemical reagents is shown. Determined that the husk of buckwheat grains contains cellulose and lignin most of all. Information is given on the use of the fruit shells of buckwheat grains as sorption materials for the removal of metal ions, oil and oil products from aqueous media. It was shown that to increase the sorption characteristics of these pollutants is possible by treating the sorption material with acidic chemical reagents and high-frequency low-pressure plasma. The parameters of acid treatment or plasma exposure are determined at which the highest adsorption indicators. Native straw and buckwheat husk are effective sorption materials for the removal of heavy metal ions and oil from aqueous media. It is possible to increase the sorption characteristics according to pollutants by a chemical or physical and chemical modification.
Analysis of power parameters of a rotary mill
Authors: Orekhova T N , Sheremet E O , Kachaev A E
Published: October 2020

The paper (publication) presents a description of the developed design of a rotary mill with a complex mechanical and acoustic effect on the dispersed material, as well as analytical studies of the parameters of energy consumption of a rotary mill, based on the main physical processes occurring in it. The research was carried out by mathematical and simulation modeling of technological processes in the grinding chamber of the mill, as well as on various technological paths of the unit. To determine the main parameters that make up the total power consumption of the unit, an approach was chosen to differentiate the processes by their physical nature and contribution to the formation of the total power consumption of the rotary mill.

The obtained results of mathematical modeling of processes occurring inside the technological paths of the unit allowed getting expressions for determining the main power costs of the unit depending on the characteristics of the unit design for each component of the total power required for effective operation of the unit at the required parameters of the dispersion of the finished product.
Features of setting and strength gain of the foam concrete massif
Authors: Savenkov A I , Gorbach P S
Published: October 2020

The paper presents a study of the regularities of the processes occurring in the matrix and aerated concrete mass at the initial time after laying and later, during the strength gain. The colloidal properties that appear in the foam concrete mix begin at the stage of mixing the components containing binder and aggregate particles, and are activated by the mixer blades. In this case, the mixture is transformed by mass transfer of the matrix material onto the foam grid and a new spatial reorientation of the bubbles under conditions of physical and mechanical effects on the thin-film structure of the foam. In technology, it should be taken into account that the processes occurring in the foam concrete mixture can be attributed to two opposite actions occurring simultaneously. First, in a freshly laid foam concrete mixture, as in any thermodynamically unstable system, sedimentation and coalescence of air pores begins, which is especially manifested at forcedly high water-solid ratios. This can lead, if the technology is not followed, to complete stratification of the mixture. Secondly, in the cement slurry, the setting and further formation of the cement stone occurs. A necessary technological condition for product quality is compliance with the optimal water-solid ratio of the mixture and ensuring the beginning of the setting of the foam concrete mass before its stratification.

It was also experimentally determined that an increase in the hardening duration of foamcement systems for more than 28 days is impractical, since it was revealed that an increase in the strength of foam concrete is similar to the same process in structural concrete. It is quite possible to achieve the strength required for foam concrete according to GOST 25485-89 within 28 days and even earlier due to the high technological discipline and the use of modern plasticizing additives.
Synthesis of a mineralizing agent for Portland cement from aluminum production waste
Authors: Endzhievskaya I G , Demina A V , Lavorenko A A
Published: October 2020

Priority directions in innovative technologies of the construction materials industry are the expansion of the use of mineral and chemical additives in the production of cements, as well as alternative raw materials and fuels in production processes. During the production of aluminum at the enterprise JSC RUSAL Krasnoyarsk, the method of electrolytic reduction of aluminum oxide or alumina dissolved in a cryolite-based melt generates fluorocarbon-containing (FCC) waste, which currently accumulates more than 16,000 tons per year. Due to the increased year-round generation of waste with a high content of carbon, fluorine and aluminum, it is urgent to develop technologies that will effectively use them as a new mineralizer product for the production of Portland cement clinker - calcium fluoride. This paper describes the thermal method of waste processing FCC for receipt of the mineralizing agent (fluorite). The disadvantage of FCC as a raw material is an increased concentration of alkali metals, whose oxides negatively affect the process of hydration of clinker minerals, and lead to the formation of efflorescence on products. To reduce their content, the finished fluorite was washed with water. Calcium fluoride as a mineralizing agent in the production of Portland cement, reduces the clinkerization temperature, increases the content of alite, changes the stability, polymorphism and reactivity of phases. The resulting fluorite with a high mass concentration of 73.9% CaF2 makes it possible to reduce the clinker formation temperature, which increases the energy efficiency of obtaining Portland cement. The technological process for removing alkaline components from the product will reduce the likelihood of destructive processes in concrete caused by the aggressive action of reactive silica aggregates and freezing and thawing processes.
Polymer composite material based on titanium hydride
Authors: Cherkashina N I , Popova E V , Pilavidou E O , Klopot E P
Published: October 2020

The article discusses the possibility of synthesizing highly filled polymer composites based on polystyrene and titanium hydride. The composites were prepared by solid-phase compaction at high specific pressure. For uniform distribution, titanium hydride was preliminarily milled in a jet-vortex mill. The particle size of titanium hydride after grinding is in the range from 0.1 to 107 μm. The modal particle diameter is 35.41 μm, and the specific surface area of the particles is 15279 cm2 / cm3. The titanium hydride content in the composites did not exceed 60 wt%. The article presents data on the density and microhardness of the obtained composites. It was found that the introduction of titanium hydride increases the physicomechanical characteristics of the composites. The Vickers microhardness of a pure polystyrene sample is 19.87 ± 0.20 HV, and a sample containing 60 wt% titanium hydride is 36.17 ± 0.78 HV (at a load of 200 g).
Heat-resistant structural composite material based on modified titanium hydride
Authors: Yastrebinsky R N , Karnauhov A A , Denisova L V , Pilavidou E O
Published: October 2020

The paper presents the results of studies of technological parameters of production, physical, mechanical, thermophysical properties and processes of gas formation during thermal heating of a composite material based on a modified fraction of titanium hydride and a Portland cement binder. The introduction of a plasticizing additive into the composite makes it possible to improve the technological and strength characteristics of the protection material. It has been shown that the decrease in the physical and mechanical characteristics of the material does not exceed 10 - 20%, which indicates its thermal stability in terms of the main performance indicators. The introduction of a boron additive does not significantly affect the physical and mechanical properties of the composite. It was found that the main gas evolution occurs during the drying of composites and practically ends after its completion. Reheating the cooled block to the initial heating temperature (300-350 °C) practically does not cause gas or water evolution, if during the cooling period the material had no contact with water.
Mechanochemical Production of Urea-citric Acid Copolymer
Authors: Miranda Eval O. , Silva Victor H. R. , Leão Mirtânia A. , Cabral-Albuquerque Elaine C. M. , Cunha Silvio , Fialho Rosana L.
Published: October 2020

Increasing non-biodegradable plastic consumption is a great factor that contributes to worldwide pollution and global warming. Mechanochemistry provides a clean, solvent-less, route for chemical reactions such as polymerization based on the absorption of mechanical energy. Urea polymers have several applications in industrial and medical area, such as paints, resins, plastic, wood glue, separating aliphatic hydrocarbons, coating, and pharmaceutical drugs. In this study, a copolymer of urea and citric acid was synthesized using a planetary ball mill as grinder with fixed reaction time and rotational speed, varying the number and material of the planetary ball mill sphere to find the effects of those two conditions in the yield percentage of the copolymer. The purified polymer was characterized by Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance – NMR. Results confirmed that polymeric material is formed by the reaction between citric acid and urea without any catalyzer using mechanochemistry. NMR results showed that the reaction occurred between urea and the acid groups at the ends of the chain, while the central COOH remained intact.
Relationship between cooling rate, microstructure evolution, and performance improvement of an Al–Cu alloy prepared using different methods
Authors: He Chen , Yu Wei , Li Yong , Wang Zhaodong , Wu Di , Xu Guangming
Published: October 2020

The relationship between the cooling rate and microstructure evolution and the performance improvement of an Al–4.5 wt% Cu alloy prepared using different casting methods was investigated. The microstructure evolution, solute element distribution, and mechanical properties of specimens prepared using different cooling rates were systematically investigated using multi-scale optical microscopy, scanning electron microscopy, transmission electron microscopy, tensile testing, and hardness testing. Upon increasing the cooling rate from 1.65 to 117.3 K s−1, the average grain size, secondary dendrite arm spacing, and width and area fraction of eutectic phases significantly decreased, and the density of the precipitated phase, super-saturation degree of solute elements, and mechanical properties improved. Through a combination of grain-boundary, solid-solution, and precipitation strengthening, the cooling rate indirectly affected the mechanical properties of the heat-treated alloy sheets. The Al−4.5 wt% Cu alloy prepared by twin-roll casting under a cooling rate of 117.3 K s−1 exhibited a strength between 145.33 and 321.79 MPa and an elongation of 11.65%, demonstrating its potential as a high-performance aluminium alloy.
Speh representations are relatively discrete
Authors: Smith Jerrod
Published: October 2020

Let

F
F

be a

p
p

-adic field of characteristic zero and odd residual characteristic. Let

S
p

2
n

(
F
)

\mathbf {Sp}_{2n}(F)

denote the symplectic group defined over

F
F

, where

n
≥
2

n\geq 2

. We prove that the Speh representations

U

(
δ
,
2
)

\mathcal {U}(\delta ,2)

, where

δ
\delta

is a discrete series representation of

G
L

n

(
F
)

\mathbf {GL}_n(F)

, lie in the discrete spectrum of the

p
p

-adic symmetric space

S
p

2
n

(
F
)
∖

G
L

2
n

(
F
)

\mathbf {Sp}_{2n}(F) \backslash \mathbf {GL}_{2n}(F)

.
The Iron Cage of Erasure: American Indian Sovereignty in Jill Lepore’s These Truths
Authors: Blackhawk Ned
Published: October 2020

This AHR Roundtable features four short essays on Jill Lepore’s widely read synthesis of American history, These Truths: A History of the United States (2018). Lepore’s framework insists that the “self-evident” truths of the nation’s founding were anything but. The driving force of her narrative is the struggle of those excluded from this magic circle—really, the majority of the country’s population—to extend those truths beyond their narrow core of elite white men. The four reviewers—Ned Blackhawk, Matt Garcia, Mary Beth Norton, and Paul Ortiz—appreciate the “shared sense of national destiny” that clearly informs Lepore book. At the same time, they chide her for what they regard as significant omissions. These critical essays invite further consideration of how best to write a fully inclusive (and therefore dramatically reconfigured) national narrative
Lepore’s America, “Our America”?
Authors: Garcia Matt
Published: October 2020

This AHR Roundtable features four short essays on Jill Lepore’s widely read synthesis of American history, These Truths: A History of the United States (2018). Lepore’s framework insists that the “self-evident” truths of the nation’s founding were anything but. The driving force of her narrative is the struggle of those excluded from this magic circle—really, the majority of the country’s population—to extend those truths beyond their narrow core of elite white men. The four reviewers—Ned Blackhawk, Matt Garcia, Mary Beth Norton, and Paul Ortiz—appreciate the “shared sense of national destiny” that clearly informs Lepore book. At the same time, they chide her for what they regard as significant omissions. These critical essays invite further consideration of how best to write a fully inclusive (and therefore dramatically reconfigured) national narrative
LiBis: an ultrasensitive alignment augmentation for low-input bisulfite sequencing
Authors: Yin Yue , Li Jia , Li Jin , Lee Minjung , Zhao Sibo , Guo Linlang , Li Jianfang , Zhang Mutian , Huang Yun , Li Xiao-Nan , Deng Zhenzhong , Sun Deqiang
Published: October 2020

The cell-free DNA (cfDNA) methylation profile in liquid biopsy has been utilized to diagnose early-stage disease and estimate therapy response. However, typical clinical procedures are capable of purifying only very small amounts of cfDNA. Whole-genome bisulfite sequencing (WGBS) is the gold standard for measuring DNA methylation; however, WGBS using small amounts of fragmented DNA introduces a critical challenge for data analysis, namely a low-mapping ratio. The resulting low sequencing depth and low coverage of CpG sites genome-wide is a bottleneck for the clinical application of cfDNA-based WGBS assays. We developed LiBis (Low-input Bisulfite Sequencing), a novel method for low-input WGBS data alignment. By dynamically clipping initially unmapped reads and remapping clipped fragments, we judiciously rescued those reads and uniquely aligned them to the genome. By substantially increasing the mapping ratio by up to 88%, LiBis dramatically improved the number of informative CpGs and the precision in quantifying the methylation status of individual CpG sites. LiBis significantly improved the cost efficiency of low-input WGBS experiments by dynamically removing contamination introduced by random priming. The high sensitivity and cost effectiveness afforded by LiBis for low-input samples will allow the discovery of genetic and epigenetic features suitable for downstream analysis and biomarker identification using liquid biopsy.
Chapter Three Didymus on Attic tragedy
Authors: Coward Thomas R P
Published: October 2020

This chapter examines Didymus’ studies on Greek tragedy, in particular on Sophocles and Ion of Chios. It demonstrates Didymus’ methods of exegesis and his use of other exegetical corpora. It explains the thinking behind some of his choices and preferences, including the mistakes. Furthermore, it examines the problems of identifying Didymean material where Didymus is not named.
ShinyButchR: Interactive NMF-based decomposition workflow of genome-scale datasets
Authors: Quintero Andres , Hübschmann Daniel , Kurzawa Nils , Steinhauser Sebastian , Rentzsch Philipp , Krämer Stephen , Andresen Carolin , Park Jeongbin , Eils Roland , Schlesner Matthias , Herrmann Carl
Published: October 2020

Non-negative matrix factorization (NMF) has been widely used for the analysis of genomic data to perform feature extraction and signature identification due to the interpretability of the decomposed signatures. However, running a basic NMF analysis requires the installation of multiple tools and dependencies, along with a steep learning curve and computing time. To mitigate such obstacles, we developed ShinyButchR, a novel R/Shiny application that provides a complete NMF-based analysis workflow, allowing the user to perform matrix decomposition using NMF, feature extraction, interactive visualization, relevant signature identification, and association to biological and clinical variables. ShinyButchR builds upon the also novel R package ButchR, which provides new TensorFlow solvers for algorithms of the NMF family, functions for downstream analysis, a rational method to determine the optimal factorization rank and a novel feature selection strategy.