bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and reactivity of 3-(1-alkynyl)chromones
Authors: Sosnovskikh Vyacheslav Ya. 
Published: October 2020

For the first time, the literature data on the methods of synthesis and reactivity of 3-(1-alkynyl)chromones are summarized and systematized. The main method for obtaining these compounds is the Sonogashira cross-coupling reaction of 3-halochromones with terminal acetylenes, and their most important chemical properties include the transformation into furans, reactions with dinucleophiles, ambiphilic [4+2]- and [4+3]-cyclizations, and also dimerization and mixed condensation of 2-methyl-3-(1-alkynyl)chromones due to the vinylogous methyl group. Except for the oxacyclization to furans, chemical transformations of 3-(1-alkynyl)chromones are accompanied by pyrone ring transformation, in which not only the carbonyl group but also the triple bond can participate. This significantly increases the synthetic value of these compounds and ensures the production of more complex heterocyclic systems based on them. The mechanisms of the reactions are discussed, the conditions for their implementation and the yields of the resulting products are indicated.
The bibliography includes 80 references.
A quantitative criterion for predicting solid-state disordering during high strain rate deformation
Authors: Becker Michael F , Kovar Desiderio 
Published: October 2020

Abstract
A quantitative criterion for predicting the onset of disordering during high strain rate deformation is defined that is based on the potential energy (PE) per atom (PE/atom). The criterion is a necessary, but not sufficient condition to predict disorder. The stress state and loading direction of the crystal must allow deviatoric displacements that can induce disordering and the strain rate must be sufficiently high. The criterion is tested using molecular dynamics (MD) simulations for Ag over a range of a stress states and loading directions relative to the crystal axis. It is found that, above a minimum PE per atom of −2.70 ± 0.01 eV/atom, the crystal becomes unstable and disorders at temperatures well below the equilibrium melting temperature. This criterion is found to be independent of stress state and loading direction, and results suggest that it can be applied broadly to other material systems and to scenarios where deformation is non-uniform and time dependent. An example is given for its application to Au in shear. We show that the minimum critical PE for disordering under high strain rate loading is estimated by finding the equilibrium PE per atom at melting, which can be obtained from a single MD simulation for each material. An example is provided that illustrates how PE/atom can be used to predict where a simulated system is with respect to the disordering threshold without conducting multiple simulations.
Detection of solid contaminants in gas flows using microwave resonant probes
Authors: Akhter Zubair , Taha Wesam , Rahman Mohammed Saif Ur , Abou-Khousa Mohamed A 
Published: October 2020

Abstract
The presence of undesirable solid contaminants can have adverse effects on the integrity of gas pipelines. One of the most common contaminants in such pipelines is black powder. Developing predictive maintenance protocols, including online quality monitoring, is imperative to ensure the on-spec supply of gas to customers and to avoid severe consequences such as pipeline blockage. In this paper, a microwave sensing system that utilizes resonant probes for the detection and monitoring of solid contaminants, is presented. The proposed probe is essentially a conventional circular waveguide with a resonant iris structure attached to the aperture. The concentration of solid contaminants in gas flows is assessed by analyzing the scattering parameters of transmitting/receiving probes at a resonant frequency, which are coupled non-intrusively to the pipeline. 3D electromagnetic simulations are performed for sensitivity analysis of the proposed sensing system. Furthermore, the detection and evaluation of solid contaminants are experimentally validated using air/sand flow in a 51 mm inner diameter pipeline. The efficacy of the proposed system is demonstrated following the successful detection of solid contaminants in the dual-phase flow. Additionally, it is also illustrated that inclusion of a resonating iris structure in the aperture of the circular waveguide results in enhanced sensitivity when compared to a non-resonant counterpart.
Numerical studies on the boundary entanglement in an optomechanical phonon laser system
Authors: Meng Qing-Xia , Deng Zhi-Jiao , Cui Shi-Wei 
Published: October 2020

Abstract
In our previous work (Meng et al 2020 Phys. Rev. A 101 023838), we discover the phenomenon that the quantum entanglement on the driving threshold line remains a constant in a three-mode optomechanical phonon laser system. In this paper, to find the conditions under which the constant boundary entanglement shows up, we explicitly study how this boundary entanglement depends on various parameters through numerical integrations. The results show that the necessary and sufficient condition is a resonant frequency match between the optical frequency difference and the mechanical vibrational frequency, and this constant value is proportional to the multiplication of the square of the optomechanical coupling strength and the resonant driving threshold power.
Comparative analysis of the parameters of generators with circular and asymmetric oscillations
Authors: Gerasimov M D , Lubimyi N S , Yakovlev E A 
Published: October 2020

Abstract
In the paper the calculation and comparative analysis of the technical characteristics and main parameters of a vibrator with circular oscillations with a driving force equal to 5 kN and a vibrating device with asymmetric oscillations with a similar driving force for two, three and four stages of vibration blocks with directional vibrations are performed based on the design methodology of vibration devices with asymmetric oscillations. The aim of this paper is to identify the positive and negative effects in the transfer of the vibrator with circular oscillations on the vibrating device with asymmetric oscillations. The paper uses a method for selecting rational ratios of static moments of debalances, which provides the highest coefficient of azimuth of the driving force of both individual stages of vibration blocks, and the coefficient of the total driving force of the entire device as a whole. This paper will be useful for manufacturers of vibration machines for construction and road vehicles.
Modeling of organizational and functional components of investment and construction controlling in the reproduction of eco-residential real estate
Authors: Krygina A M , Avilova I P , Oberemok M I , Grebenik A G 
Published: October 2020

Abstract
This article is devoted to the development of a structural and functional model for the formulation of high-performance regional business systems in the context of implementing eco-projects at various levels in a situation where supply exceeds demand. This approach generally corresponds to the current problems of macro and micro levels in the domestic and global economy and takes into account its negative impact on the construction industry. The theory is based on situational modeling with the identification of two key situations according to the principle of transformational development of local internal competition. The paper proposes zoning of a standardized life cycle of planning and controlling of the regional environmental programs. A structural and functional model of system formation of consortium-type organizational structures has been developed to regulate local and cluster competitiveness in construction on the meso-level. It suggests a principal situational economic model of functioning of mortgage and investment projects and programs for the development of competitiveness in territorial reproduction systems. It also provides the conceptual model of the life cycle of managing the cost of mortgage and investment programs and observes two periods of the life cycle of managing investment projects.
The dynamics of the stability of the functioning of ZAO Belgorodskij cement in 2016-2019
Authors: Slabinskaya I A , Benderskaya O B 
Published: October 2020

Abstract
Stability of functioning is one of the main goals of managing economic entities, whether they are independent business units or divisions of business associations. The complexity of this economic category determines the need to improve scientifically grounded instruments for measuring, assessing and monitoring the level of sustainable functioning. One such tool is the comparative comprehensive assessment (CA) of the stability of functioning, which is described in this article. The assessment author’s methodology is based on a system of 12 indicators of the stability of functioning. For a dynamic comparative assessment of enterprise, the author’s method of calculating a comprehensive assessment is used - a modified method of scoring. The object of the research is ZAO Belgorodskij cement, one of the largest enterprises in the building materials industry in the Belgorod region. The subject of the research is the dynamics of the stability of the functioning of ZAO Belgorodskij cement in the period 2016-2019. During this period, there was a constant struggle between the local authorities and the management of the enterprise for the closure of the plant, which the plant managers oppose. The objectives of the study are to improve the methodology for a comprehensive assessment of the stability of functioning and assess the impact of uncertainty in the position of the plant on the stability of its functioning.
Efficiency of using shungite filler for modifying organic binder
Authors: Yadykina V V , Vyrodova K S , Potapov E E 
Published: October 2020

Abstract
Modification of bitumen with various additives, including polymer ones, is one of the most effective ways to regulate the performance properties of asphalt concrete. Due to the high cost of polymers, a promising area of research is to reduce the polymer content, for example, by introducing mineral filler into its composition. A wide range of properties and unique structure of fullerene-containing natural shungite allow it to be used in various branches of science, industry and technology to create a variety of materials and determine the search for new areas of its application. One of the ideas that are currently under development is the use of shungite in conjunction with an organic binder used for the production of asphalt concrete. The work is devoted to the study of the influence of fine shungite on the characteristics of polymer-bituminous binder (PBB) and asphalt concrete. It is shown that the introduction of shungite into the PBB increases its viscosity, adhesive and cohesive properties, and the homogeneity of the mixture. This is due to the unique composition, structure and properties of shungite. The positive influence of the use of polymer shungite binder on the quality of asphalt concrete was established. With the introduction of 5% shungite in the PBB composition, the strength at 20 and 50°C, the strength of water-saturated samples, and the shear stability of polymer asphalt concrete significantly increased. This made it possible to reduce the polymer content of PBB by 10%.
The modern information technologies in construction for improving occupational safety
Authors: Klimova E V , Semeykin A Yu , Sinebok D A , Khomchenko Yu V 
Published: October 2020

Abstract
Today, construction takes first place in the number of industrial accidents, including severe and fatal ones. Inconsistency of jobs, work at height, work in extreme conditions, adverse weather factors, all this and much more is the cause of traumatic factors. The article discusses the implementation aspects of modern information technologies that allow you to assess the psycho-emotional state of the employee in real time and make timely decisions on the organization of work safety. Based on the results of the analysis, a “Psychophysiological Monitoring System” is proposed. Existing analogues of such systems are not used in production, more often they are designed to assess the physiological state of athletes. The technology of analysis and assessment of the state of workers is presented, which a complex of interrelated parts is such as: the main sensor module, local receiving and transmitting device, stationary receiving and processing device, sensors for evaluating external conditions, a database and a server for data transmitting and processing. Based on the developed hardware-software complex, measures are proposed for the prevention of injuries in construction during construction and installation works on height.
Lightweight materials based on wood waste
Authors: Yespayeva A S , Altayeva Z N , Sarsenbayev B K , Karshyga G O , Sauganova G R 
Published: October 2020

Abstract
This paper discusses ways of recycling woodworking waste into light aggregate, optimal compositions of modified binders, as well as the mechanism of cement hydration in the presence of dispersion polymer powders. The methods of obtaining light aggregate based on woodworking waste by granulating in a disc granulator, which is a plate with a tilt angle of 450 and a number of turnovers of 17-19 rpm, are considered. Methods for obtaining granulated aggregate using sawdust of various fractions by the roasting free method are presented, optimal granulation modes are determined, and the main characteristics of the resulting aggregate and concrete based on them are studied. The optimal composition of granulated aggregate on modified cement provides 40 … 60 % of wood processing waste, 60 … 40 % of cement, 25 … 32 % of water and granulation time - 7 … 9 minutes. With this composition, the bulk density of the resulting aggregate corresponds to 850…750 kg/m3, the maximum strength of the granules when compressed in the cylinder is 3.5…4.1 MPa. The optimal content of the polymer additive in the binder is in the range of: mowilith - 0.4…0.7 % and tylose - 0.21…0.13 %. Granulated aggregate on modified aggregate has a frost resistance in the range of F35… F50. The choice of granulated aggregate on modified cement showed the effectiveness of the aggregate for light concretes. The strength characteristics of modified concrete of 25-75 brands were studied. The mechanical properties of modified concrete depending on the average density were studied. Concrete with an average density of 1000 kg/m3 has M25 brand, at 1200 kg/m3 - M35, at 1300 kg/m3 - M50, at 1500 kg/m3 - M75.
Movement of particles of concrete mixture aggregate subjected to vibration by cylindrical punches
Authors: Kirilov I V , Khanin S I , Voronov V P 
Published: October 2020

Abstract
For compaction of the concrete mixture in the manufacture of reinforced concrete products using the formless production method on long stands, as a universal and widespread method, vibration is used. The aim of the study was to establish the regularities of the process of spreading a cylindrical punch of a continuous formless machine of vibration oscillations on the aggregate particles of a viscous concrete mixture in the form of crushed stone and sand. The chaotic movement of filler particles of various sizes with an arbitrary number of degrees of freedom, due to their large number, movement, and exchange of impulses, is considered. The problems of the development of mathematical descriptions of the motion of spherical filler particles of different grain size in the vibration of a cylindrical punch with a viscous environment and determination of their average values of travel speed and distance through random motion were solved, the average values for these parameters at vibration of the punch with frequencies and amplitudes that are applied in industrial conditions were found. In the course of the work, the method of mathematical modeling was used. The result of this work is to establish the possibility, for particles of different sizes, of varying the average values of the speed of movement and the path traversed in a viscous environment, carried out by changing the characteristics of the vibration of the punch. The regularities of changes in the parameters under consideration for filler particles of various sizes depending on the frequency and amplitude of vibration oscillations of the punch surface are considered.
Modeling the external business environments for the Vietnamese construction SMEs in a transition economy
Authors: Nguyen The-Quan , N Preece Christopher 
Published: October 2020

Abstract
Vietnam has been shifting from a centrally planned economy with subsidy schemes, to a socialist-oriented market economy with multiple economic components. The internal dynamics and external pressures have caused many changes in the environment for small and medium size construction enterprises. This research models the external environment in order to aid understanding of the strategic management of such contractors in the construction industry of Vietnam. Semi-structured interviews of senior managers were combined with a mailed questionnaire to collect data. Seven major concepts were found to emerge including the economic administration of the country, the legacy of the old system, changes in society, nature of the workforce and the variety of business styles found. The research results show that the behaviour of key stakeholders has a major impact on the strategic/competitive behaviour of the concerned firms and their profitability.
Effective risk management of transport facilities construction
Authors: Spiridonov E S , Logvinenko A A , Dukhov A A 
Published: October 2020

Abstract
From the point of view of the resource intensity of creating communication tools (investment, labor, materials, energy, time), the leading place in production belongs to transport, and in it – railways and highways. This study examines various aspects of the application of the risk management system in the management of transport construction. Methods of risk minimization depending on the type of risk are presented: the risk of legal error, the risk of the customer’s insolvency, the risk of a suboptimal loan portfolio, and the risk of non-fulfillment of financial indicators. A matrix form of comparison of identified risks is proposed for the development of the most effective methods of managing them. Using the example of the insolvency risk, which is one of the most characteristic for transport construction, the possibility of assessing the risk by a quantitative method is shown. The risk was quantified using the G. Markowitz model. To assess risks, it is proposed to use a coefficient method that allows determining the criteria that characterize their solvency based on an express assessment of the financial condition of customers, and justify recommendations for concluding contracts with them for the construction of a transport facility. The proposed matrix form of comparison of the identified risks allows formulating recommendations for reducing the impact of risks on the stability of the construction production process in a more reasonable way.
Improvement directions of technical regulations in the field of reinforced cellular concrete structures
Authors: Kladieva P V , Koshlich Yu A 
Published: October 2020

Abstract
Effective management of real estate complexes, which determines the rational capital intensity of ownership of buildings and structures, largely depends on the consumer qualities of building materials and products included in the investment and construction project at the design stage. The implementation of the principles of rational design, which are regulated in unique and technically complex and responsible structures, is still not properly reflected in the design of second-class objects of responsibility, which, however, make up more than 70% of the capital intensity of the construction market, mainly housing. Complex composite materials that combine innovative and energy-efficient components and technologies, as well as structures made from them that contain significant reserves of load-bearing capacity, which are opened and implemented by improving design standards and rational technical solutions, have the greatest potential for rationalization. Reinforced cellular concrete, which effectively combines load-bearing and enclosing functions, is one of the most popular construction technologies in the perspective practice of low-rise construction. Currently, however, the design of reinforced structures made of cellular concrete in Russia, abroad, mainly performed according to the normative documents, often not taking into account the significant differences in physical and mechanical properties, material structure, principles and working mechanisms of various types of concrete under load, as well as the uniqueness of plastic properties of cellular concrete when assigning the form and composition of discrete reinforcement. In this regard, there is a need to revise and systematize existing standards that contain requirements for the design of directly reinforced structures made of cellular concrete, generalize European experience and these standards, update information in them, as well as develop modern national standards in this area. In addition, the practice of designing bent cellular concrete structures has revealed a significant reserve for increasing the load-bearing capacity of these elements, associated with insufficient inclusion of the material of the traditionally used rod reinforcement due to the primary destruction of the contact layer (pulling the reinforcement). In order to increase the durability and reduce the resource intensity of national cellular concrete structures, the adopted methodology for their design needs to improve both the regulations that establish the principles and rules for calculating reinforcement elements of structures, and structural elements used in precast and in-situ practice of discrete reinforcement.
Improving the efficiency of the material grinding process
Authors: Romanovich A A , Amini Ebrahim , Romanovich M A 
Published: October 2020

Abstract
The paper provides an analysis of grinding systems used in the world practice, including the main technical solutions in the field of fine grinding of materials using a ball mill, and also presents indicators of their efficiency. It was found that the grinding systems of the partitioned grinding process with pre-grinding in a press-roll grinder showed the greatest efficiency from their use. However, today in various countries, free-standing units are used for deagglomeration of pressure-pressed semi-finished products, which require additional space for their placement and operation and maintenance costs. The authors describe the design of a press-roll unit with a device for breaking pressure-pressed materials, which allows reducing these costs, as it performs the following technological operations: volume-shear deformation of the material is carried out due to the conical profile of the main rolls; the compressed materials are disaggregated in the reverse direction of compression by means of additional rollers that have a reverse taper to the main rolls. A scientifically-based method for calculating the energy index of a new design of press roll unit is proposed, which allows for the energy calculation of these machines.