bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart physics with an oscillating beverage can
Authors: Kaps A , Stallmach F
Published: May 2021

A digital learning-teaching environment is introduced in which undergraduate students are challenged to connect the basic physical concepts of oscillation, buoyancy and data analysis via an authentic experiment. The damped oscillation of a cylindrical body swimming upright in water is measured via the MEMS acceleration sensor of a wireless MCU SensorTag. The data are recorded with the app phyphox on a smartphone or tablet. The theoretical oscillation period and the experimentally determined periods obtained via different data analysis roots are found to agree showing an excellent theory-experiment interplay. The proposed experiment is suited for the physics home lab e.g. under the current pandemic situation or for open university courses as well as for physics lab courses.
Designing an instructional module to teach light diffraction by a grating to secondary students applying a STEM-integrated approach
Authors: Chuasontia Itsarapong , Sirirat Tanita
Published: May 2021

This research aimed to design an instructional module to teach light diffraction by a grating to secondary students applying a science, technology, engineering, and mathematics (STEM)-integrated approach. Based on this approach, instructional management integrated the disciplines of physics and mathematics with engineering design process principles, while information searches, assessment, and evaluation drew on technology. The module involved working out a solution to the real-world scientific problem of constructing a spectroscope in the environment of cooperative learning. Upon completion of the module, the students were expected to demonstrate a thorough understanding of light diffraction by the grating as well as problem-solving skills. To evaluate its effectiveness, the module was trialed on thirty 11th grade students in a Thai school in Pathum Thani, Thailand. The findings revealed that the implementation of the module enabled the students to achieve a statistically higher post-test score than that for the pre-test at the significance level of 0.05. As a result of the module, the students also exhibited a high level of academic development, as indicated by the class normalized gain of 0.82. Finally, the module was perceived by the students as being suitable for their level, offering them a chance to apply classroom knowledge to authentic problems and hence accumulating their hands-on experience, enhancing their problem-solving skills through the application of the engineering design process, and improving their team-working ability.
Estimating star distances with a light bulb
Authors: Craig David M , Leslie Lewis R
Published: May 2021

A practical experiment is described to estimate the distance to a star using simple equipment, suitable for secondary or undergraduate students. The brightness of the star is visually matched to a miniature filament lamp, and its distance inferred from the inverse square law. Students gain an appreciation of astronomical units and practice in manipulating powers of 10. By additionally applying knowledge of the H-R diagram and black body radiation, accuracy can be improved to one order of magnitude.
The next-to-leading spin-orbit effects on the general motions in Kerr spacetime
Authors: Yang Bo , He Guansheng , Lin Wenbin
Published: May 2021

We derive the second-and-half post-Newtonian solution for the generally inclined motion of a test particle in Kerr spacetime when the effects of the spin-induced quadrupole are negligible. The next-to-leading order spin-orbit effects on the test particle’s motion are obtained, which are important in fitting the motions of the extremely-mass-ratio-inspiral systems and also calculating the gravitational wave radiated by this kind of systems at the second-and-half post-Newtonian order.
The cosmological evolution of self-interacting dark matter
Authors: Egana-Ugrinovic Daniel , Essig Rouven , Gift Daniel , LoVerde Marilena
Published: May 2021

We study the evolution of cosmological perturbations in dark-matter models with elastic and velocity-independent self interactions. Such interactions are imprinted in the matter-power spectrum as dark acoustic oscillations, which can be experimentally explored to determine the strength of the self scatterings. Models with self interactions have similarities to warm dark matter, as they lead to suppression of power on small scales when the dark-matter velocity dispersion is sizable. Nonetheless, both the physical origin and the extent of the suppression differ for self-interacting dark matter from conventional warm dark matter, with a dark sound horizon controlling the reduction of power in the former case, and a free-streaming length in the latter.
We thoroughly analyze these differences by performing computations of the linear power spectrum using a newly developed Boltzmann code. We find that while current Lyman-α data disfavor conventional warm dark matter with a mass less than 5.3 keV, when self interactions are included at their maximal value consistent with bounds from the Bullet Cluster, the limits are relaxed to 4.4 keV. Finally, we make use of our analysis to set novel bounds on light scalar singlet dark matter.
Novel accelerated Stochastic Progressive Photon Mapping rendering with neural network
Authors: Xing Qiwei , Chen Chunyi , Li Zhihua
Published: May 2021

Recently, deep learning-based approaches have led to dramatic improvements for Monte Carlo rendering at the low sampling rate. Most of these approaches are aimed at path tracing. However, they are not suitable for photon mapping. In this paper, we develop a novel accelerate stochastic progressive photon mapping approaches with neural network. First, our framework utilizes the particle-based rendering and focuses on photon density estimation. We train a neural network to predict a kernel function to aggregate photon contributions at shading point. Then we construct a estimation images with the prediction network. During experiments, we could find that there are spike pixels and noises in estimation images sometimes. So we present the improved denoising network to post-process the estimation images. Finally, we can obtain the high-quality reconstructions of complex global illumination effects like caustics with an order of magnitude fewer photons compared with previous photon mapping methods. Besides, our denoising network can reduce most multi-scale noises on both low-frequency and high-frequency areas while preserving more illumination details, especially caustics, compared with other state-of-the-art learning-based denoising methods.
Two degree-of-freedom robotic eye: design, modeling, and learning-based control in foveation and smooth pursuit
Authors: Rajendran Sunil Kumar , Wei Qi , Zhang Feitian
Published: May 2021

With increasing ocular motility disorders affecting human eye movement, the need to understand the biomechanics of the human eye rises constantly. A robotic eye system that physically mimics the human eye can serve as a useful tool for biomedical researchers to obtain an intuitive understanding of the functions and defects of the extraocular muscles and the eye. This paper presents the design, modeling, and control of a two degree-of-freedom (2-DOF) robotic eye, driven by artificial muscles, in particular, made of super-coiled polymers (SCPs). Considering the highly nonlinear dynamics of the robotic eye system, this paper applies deep deterministic policy gradient (DDPG), a machine learning algorithm to solve the control design problem in foveation and smooth pursuit of the robotic eye. To the best of our knowledge, this paper presents the first modeling effort to establish the dynamics of a robotic eye driven by SCP actuators, as well as the first control design effort for robotic eyes using a DDPG-based control strategy. A linear quadratic regulator-type reward function is proposed to achieve a balance between system performances (convergence speed and tracking accuracy) and control efforts. Simulation results are presented to demonstrate the effectiveness of the proposed control strategy for the 2-DOF robotic eye.
Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016
Authors: Zhang Xuesong , Lark Tyler J , Clark Christopher M , Yuan Yongping , LeDuc Stephen D
Published: May 2021

After decades of declining cropland area, the United States (US) experienced a reversal in land use/land cover change in recent years, with substantial grassland conversion to cropland in the US Midwest. Although previous studies estimated soil carbon (C) loss due to cropland expansion, other important environmental indicators, such as soil erosion and nutrient loss, remain largely unquantified. Here, we simulated the environmental impacts from the conversion of grassland to corn and soybeans for 12 US Midwestern states using the EPIC (Environmental Policy Integrated Climate) model. Between 2008 and 2016, over 2 Mha of grassland were converted to crop production in these states, with much less cropland concomitantly abandoned or retired from production. The net grassland-cropland conversion increased annual soil erosion by 7.9%, nitrogen (N) loss by 3.7%, and soil organic carbon loss by 5.6% relative to that of existing cropland, despite an associated increase in cropland area of only 2.5%. Notably, the above estimates represent the scenario of converting unmanaged grassland to tilled corn and soybeans, and impacts varied depending upon crop type and tillage regime. Corn and soybeans are dominant biofuel feedstocks, yet the grassland conversion and subsequent environmental impacts simulated in this study are likely not attributable solely to biofuel-driven land use change since other factors also contribute to corn and soybean prices and land use decisions. Nevertheless, our results suggest grassland conversion in the Upper Midwest has resulted in substantial degradation of soil quality, with implications for air and water quality as well. Additional conservation measures are likely necessary to counterbalance the impacts, particularly in areas with high rates of grassland conversion (e.g. the Dakotas, southern Iowa).
Effect of Powder Composition on the Preparation of SiCfoam/Al Co-continuous Phase Composites by In-situ Reactive Pressureless Infiltration
Authors: Xiao Qing , Jiang Guojian
Published: May 2021

The SiCfoam/Al co-continuous phase composite was prepared by in-situ reaction pressureless infiltration (ISRPI). The influence of powder ratio on the impregnation effect and the mechanical properties of the material was studied. The relationship between the mechanical properties and the interfacial reaction was discussed. The results show that the addition of Mg powder of 8% mass fraction increases the impregnation effect, and the formed magnesium spinel strengthens the bonding interface, which makes the compacting of the composite improve. At the same time, adding 2% mass fraction of Si in the infiltrated powder can inhibit the production of brittle material Al4C3and improve the mechanical properties of the composites. The compressive strength of SiCfoam/Al co-continuous phase composites with good interfacial bonding reaches 832MPa.
Prediction of ultimate burst pressure and comparison of failure criteria for thermoplastic composite pipes
Authors: Ge P , Xia H , Liu Q , Shi C , Xiao W , Jia X , Xu Y
Published: May 2021

Thermoplastic composite pipes (TCPs) are becoming the ideal substitute for traditional steel pipe due to its superiorities including light weight and corrosive resistance. The cross-section of TCPs consists of an inner liner, a laminate layer, and an outer jacket. The laminate layer is made of multi-plies of helically wound continuous fibre reinforced unidirectional tape. In the present study, a three-dimensional (3D) theoretical model and a 3D finite element model were developed to analyse the stress state of a TCP under internal pressure. With a selected failure criterion for composite laminate, the ultimate burst pressure of a TCP can be predicted. By comparing the predicted burst pressure with the experimental results, several commonly used failure criteria were compared in terms of their accuracy.
Quantitative Changes in the Hepatopancreas Cells of the Bivalve Mollusk Batissa Violaceae Exposed to Anthropogenic Activities in Catubig River, Northern Samar, Philippines
Authors: Salinas RI
Published: May 2021

This study aims to determine the quantitative changes in the hepatopancreas cells of bivalve mollusk as a bioindicator of pollution on aquatic species. Clams Batissa violaceae inhabiting in Catubig River, Northern Samar was used as the bioindicator of pollution. Clams were collected during high flow and low flow periods at two different sites along the Catubig River. Pooled hepatopancreas were used for quantitative analyses; from chronically exposed group, depurated laboratory control group and those clams that were brought back to the river and immersed for 72 hrs. Histological sections of hepatopancreas were examined by Ken-a-vision microprojector microscope. Results have shown that acute exposures in the number of digestive tubules were significantly different from chronically exposed group of clams. The hepatopancreas epithelium heights also showed significant differences during high and low flow regimes. Overall, quantitative changes found in the hepatopancreas cells after acute and chronic exposures, could serve as a biomarker of exposure to pollutants.
Analysis of Horizontal to Vertical Spectral Ratio (HVSR) Curve Results from Processing using Interpolated Finite Impulse Response (IFIR) Filter
Authors: Olivia M A , Rochman J P G N , Warnana D D
Published: May 2021

Microtremor is recorded with a device that is very sensitive to subsurface soil vibrations, that unwanted noise frequency waves are often also included. For this reason, processing needs to be done using filters that can attenuate the noise. In the previous research, signal decomposition was performed using the Interpolated Finite Impulse Response (IFIR) filter and resulted attenuation at the desired frequency value. Using the MATLAB program, microtremor data are processed with IFIR filtering, smoothing, calculation of: Horizontal to Vertical Spectral Ratio (H / V) curve, natural frequency (f0) and standard deviation (σ). The same process was carried out using Butterworth, Gaussian, and Cosine filters as a comparison with the Geopsy program. As a result, the amplitude characteristics obtained can provide a value of f 0 < 2.5 Hz. The value of f0 obtained using IFIR filter is also stable, proven by the standard deviation ranging from σ = 0.009 - 0.83 Hz, with an average of σ = 0.132 Hz. In conclusion, the IFIR filter can provide a well-attenuated H/V curve according to the specified cutoff frequency, which was 2 Hz. The IFIR filter is also considered capable of being applied to the HVSR method Microtremor data. Lowpass IFIR filter can attenuate high-frequency noise in microtremor data.
Current status and prospect of research on combine harvester header for rape
Authors: Wang Hanhao , Li Yaoming , Qing Yiren
Published: May 2021

Rapeseed is one of the most important oil-bearing crops in China. Because of its poor efficiency, the planting area is in a trend of declining year by year. In order to change the status quo of low efficiency and stimulate farmers’ enthusiasm for planting oilseed rape, it is of great significance to vigorously promote the mechanized harvest in the process of rapeseed production. The rape header is an important part of the rape combine harvester. It is different from the header structure of common rice and wheat combine harvesters, and the header depth is larger. At the same time, in order to solve the problem of dense branches and cross-linking of rapeseed, in addition to the main cutter, reel and screw conveyor, the rape header also needs to be equipped with a vertical splitting cutter on the side. In this way, the entangled branches are cut and the loss of shattering can be reduced. Head loss accounts for a considerable proportion of the total loss during the rape harvest. By reasonably configuring the structure of the rape header and optimizing the working parameters, the vibration of the header and the power consumption of the header can be reduced, and the work efficiency can be improved. It is of great significance to reduce the mechanical harvest loss of rape and increase the efficiency of rape planting. This article introduces the current status and progress of the research on the working structure of the rape header at home and abroad. Point out the existing problems and put forward suggestions for the development of rape header in the future.
Transcriptomic analyze of the less branches of Brassica napus L. suitable for mechanized harvesting
Authors: Qing Yiren , Li Yaoming , Ma Zheng
Published: May 2021

Rapeseed (Brassica napus L.) is one of the main oil crops in the world. Its multi branching characteristics cause great difficulties and losses to mechanical harvesting. Less branched plant type is a favorable feature for promoting mechanical harvesting. In this paper, a natural mutant rape of less branches with NY12 (Ningyou 12) as background was obtained, which was named sfz (shao fen zhi, meaning less branches in Chinese). The mutant showed a significant decrease in branching and a significant increase in the lowest branch height, which are beneficial to harvest. Transcriptomic analysis of shoot tip tissue showed that the expression of gens related to strigolactone is up-regulated, which promotes its inhibitory effect on plant branching, and the expression of genes related to cell division cycle and cytoplasmic division were all down regulated. It is speculated that the decrease of cell division may also result in the decrease of branching. The research provides a basis for the formation of branching and promoted the development of mechanized harvesting.
Using CiteSpace Knowledge Information Visualization Software in the Visual Analysis of the Law Research: Set Juvenile Sexual Assault as an Example
Authors: Zhu Ai’nan , Yang Xue , Cui Daiyao
Published: May 2021

The crime of sexual assault is of one essential aspect of law research in China nowadays. At present, the number of domestic research literature on the crime of sexual assault on minors is rising. In this paper, CiteSpace knowledge information visualization software, SPSS, excel analysis software are used to analyze all the sexually assaulting juvenile literatures collected in CNKI in the past 10 years, and show the current situation and structural characteristics of the research on sexual assault juvenile crime in the form of knowledge network atlas, so as to grasp the current situation of the research on juvenile sexual assault crime in China from a macro perspective. This paper aims to provide a valuable reference for the research on the attack and prevention of juvenile sexual assault.
Cause Analysis and Management Countermeasures for Unsafe Drinking Water Quality in Rural Guangxi China
Authors: Ding Haoqing
Published: May 2021

In recent years, as China has been vigorously promoting the construction of drinking water safety project in rural areas, rural drinking water safety is guaranteed to some extent, but the safety of water quality is still not up to standard in some areas. In view of the situation of drinking water safety in rural Guangxi China, according to the authoritative judgment method of safe drinking water, this thesis analyzes the present situation of rural drinking water safety in Guangxi, and decides that the major causes of unsafe drinking water quality in rural Guangxi include the exceedance of content standard of hazardous substances in drinking water sources, pollution in transportation and treatment process of drinking water, lack of water quality monitoring ability and imperfect management mechanism after the completion of water supply project. Furthermore, the thesis proposes management strategies to improve the safety of water supply quality in rural Guangxi, such as the construction of consolidation and promotion project of rural drinking water safety, the implementation of contiguous water supply project, the establishment and perfection of engineering operating mechanism, the strengthening of quality supervision on rural drinking water safety projects, the use of Internet of Things and big data technique for real-time monitoring, the strengthening of the management on drinking water conservation districts, the improvement of water treatment technique and timely check and solving of the defects. The aim is to enable more rural people to drink safe water with the above management strategies.
Recovery behaviors of acid-modified cement hydration material on phosphorous
Authors: Jiang Bo
Published: May 2021

Silicate cement hydration product is a promising phosphorus adsorption material. In view of the strong alkali characteristics of early hardening cement paste, this study adopted acid leaching method to modify and then investigated its phosphorus recovery performance. The results showed that acid modification could weaken the strong alkali property, nevertheless, it also lowered phosphorus removal efficiency. The decline of phosphorus recovery was closely related to the depletion of calcium source. By the fit calculation, it can be determined that the adsorption kinetics of modified material on phosphorus met the pseudo-second-order model. This was consistent with the behavior of unmodified material. Additionally, XRD analysis demonstrated that the phosphorus species enriched on the surface of modified material mainly consisted of hydroxyapatite and variscite, which was different from the brushite of unmodified material. Acid modification would provide much more aluminum sites on the adsorption of phosphorous.
Problems of environmental management: international experience
Authors: Guseva I A , Kuznetsova M G
Published: May 2021

The rational use of natural resources and environmental protection are crucial global issues. The article analyzes the experience of Russia and some foreign countries (Mongolia, China, and India) that have already launched a campaign aimed at developing environmentally friendly technologies. In Russia, this process has been recently initiated. The authors consider the problems of rational nature management in terms of protection of specially protected natural territories and implementation of innovative technologies by enterprises. Environmental threats hinder the development of specially protected natural areas and worsen the environment in specially protected areas. The article focuses on practical activities of environmental protection inspectors, presents statistical data on environmental offenses committed in specially protected natural territories of Irkutsk region. The development of environmental technologies is promising in Russia. “Green” and innovative technologies have already become the basis of many government policies and determine the development of new economic models. The experience of foreign countries shows a positive result of the use of the best available technologies, but the implementation of this mechanism requires time and various tools.
Assessment of land resources for the purposes of housing construction in suburban areas of Irkutsk city
Authors: Kulagin D S , Matveeva M V
Published: May 2021

The article examines the level of housing construction and the dynamics of its key indicators, the volume of the housing stock of the Irkutsk region. The objectives of the national project “Housing and urban environment” and the regional project “Housing” to increase the volume of housing construction are considered. The assessment of the provision of housing construction with land resources was made.
Evaluation of the use of thermoelectric generators in rooms with excessive heat release
Authors: Yu Shelekhov I
Published: May 2021

The purpose of the work was to evaluate new methods and new technology for the manufacture of thermoelectric modules for use in rooms with excessive heat release. Investigation of heat release parameters for the possibility of converting them into electrical energy. A new design of the thermoelectric module with a new topological pattern is applied. The research of the parameters of new thermoelectric modules is carried out using the developed installation, with the help of which it was found that the efficiency of the new design is 16.5% higher than that of classical thermoelectric modules. At the same time, it was found that the cost of the new design is 8 times less than that of classical thermoelectric modules. The heat release of the equipment of the operating boiler house, located in the city of Irkutsk, was studied. In the course of research, it was revealed that the technological equipment intended for servicing four fuel oil boilers of the «DE 16-14 GM» type emits heat energy of about 100 kW, which can be converted into electrical energy with an efficiency of more than 30%. The studies have shown that there are innovative technologies, using which it is possible to convert heat losses in buildings with excessive heat release into electrical energy, thereby increasing the efficiency of the equipment used.
Research of solar energy potential in the Eastern Siberia
Authors: Tunik A A , Yu Tolstoy M
Published: May 2021

The article presents the results of solar energy potential studying in the Eastern Siberia region (in particular the Irkutsk Oblast) of the Russian Federation by integrating data from three databases: observatories of the CIS countries, NASA and the Hong Kong Observatory. The analysis of the databases was carried out taking into account their error degree. The results obtained make it possible to identify the year periods in when solar power plants can be used as efficiently as possible, both for generating thermal energy and electricity. In turn it will allow optimizing both the solar stations and the design of the solar panels and collectors themselves. The research methodology presented in this article can also be applied to assess the solar energy potential in other regions of the Russian Federation, which can be used for systematizing the data obtained for further calculations of solar plants required capacity and their design.
New information about the education of architect Robert Marfeld in the context of the influence of European architecture on the formation of the architectural identity of Irkutsk
Authors: Glebova N M , Klamer M , Alekseeva V O
Published: May 2021

This article aims to highlight the fact about the influence of European education on the work of the Russian architect with German roots, Robert Marfeld. On the basis of the collected bibliographic and archival materials, his projects and the work of his teacher - the famous Austrian architect Theophil Hansen, who taught a Master class at the Academy of Fine Arts in Vienna, worked with the greatest Austrian architects of the mid-19th century - are studied. In this context, a project of a vocational school in Irkutsk, carried out by Marfeld, is considered. The stylistic features of Marfeld’s architecture, especially in the initial period of creativity, are in many ways similar to the architecture of Hansen and his school. This is also due to the trends in architecture and construction of that period, especially in Germany and the Austro-Hungarian monarchy. Leading Russian architects were educated in Europe. European architects taught in St. Petersburg. Thus, the work of German and Austrian architects in Russia and in Irkutsk played a significant role in the formation of architectural identity, which contains many different characteristics, which was highlighted in previous articles by the authors, but also features inherent in the styles developed by the German and Austrian architectural schools.
Ceramics in architecture
Authors: Kulakov A I , Ri A U
Published: May 2021

The article analyzes the role of decorative ceramics in solving architectural problems of the traditional “architecture - painting - sculpture” triad and organizing the architectural and spatial environment. Ceramists use ceramics in unusual ways. Their solutions are crucial for the synthesis of arts. In the current architectural space, ceramics should not be considered as a building material or an element of the decorative or monumental arts. Its applications in the architectural spatial environment require studies of fundamental problems of the synthesis of arts. A literature review has identified an unusual pace of ceramics development. It penetrates into adjacent areas and shows a trend towards “omnipresence”. Therefore, a deep analysis of the ongoing processes is required. The appearance of a modern city is determined by the huge scale of construction. At the same time, the issues of emotional enrichment and individualization of the architectural space are acute. Irkutsk is famous for its rich historical experience in using ceramics as a building material. It is necessary to preserve the individual appearance of the city with a rich historical heritage. New applications of the ancient material are determined by its remarkable plasticity, color and texture properties. Combining plasticity and color, ceramics can be used as a material for monumental sculpture and jewelry modeling. It is cheap and possess good artistic and utilitarian qualities.
The Church Construction of Eastern Siberia in the seventeenth to the first half of the nineteenth centuries
Authors: Naumova O , Naumov I
Published: May 2021

The article is devoted to the history of church construction evolution in Eastern Siberia during its fledging years. It provides specific characteristics of the church development policy in the period under review. It is shown contribution of the clergy and especially the Irkutsk bishops to this process. There are presented the main architectural styles that prevailed in the construction of temples in Eastern Siberia in the 17th to the first half of the 19th century, organizational and financial aspects of church construction and its role and place in the cultural development of the region and as a “cultural heritage”.
The song or arpentage? In the spatial context of the quarters of the historical center of Irkutsk
Authors: Selivanov R A
Published: May 2021

Problem. In modern Irkutsk, the nature of the relationship between the cadastral plan of the quarter and its development is a problem. The essence of this problem is the inconsistency of the boundaries of land surveying with buildings on these sites. Goal to develop a methodology for interacting the spatial grid of a quarter with its cadastral plan. Results: A proposal is made for a method of shaping in the context of a historical city based on a spatial grid that includes a mechanism for interacting with the cadastral plan of the Irkutsk quarter. The analysis of the spatial situation of the historical quarter is performed. Spatial and contextual requirements for the proposed architectural object within the boundaries of this quarter have been developed. Conclusions: To get a high-quality project result in working with the districts of the city center of Irkutsk, a contextual approach is necessary, which includes, in addition to the traditional preproject analysis, research of the spatial structure of the historical environment of the districts.[11] The strategy of spatial development of blocks in the historical center of Irkutsk does not have clear and meaningful prospects without resolving the contradiction in the relationship between the compositional integrity of building blocks and their land surveying. An effective mechanism of urban planning regulation is needed to implement the design methodology of shaping in the context of a historical city based on a spatial grid.
Implementation of an optimization algorithm using modified Lagrange functions on the example of a steel hinge-rod system
Authors: Dmitrieva T L , Kablukov A V
Published: May 2021

An example of the optimal design of a steel truss with the use of modified Lagrange functions is considered. To solve the problem, it is necessary to select the cross-sectional areas of the truss at a given interval by minimizing its volume, provided that the regulatory requirements for strength and rigidity are met. The external diameters of the sections of the truss elements vary. A detailed algorithm for solving the problem is presented. The algorithm is implemented in the mathematical packageMathCAD, which allows you to visually trace the sequence of commands, as well as receive graphs reflecting the state of the problem at each iteration.
Strength of cellular concrete as a function of density under axial uniaxial compression
Authors: Savenkov A , Zaenec E , Ketner A
Published: May 2021

The purpose of this work is a comparative analytical assessment of the axial compressive strength of foam concrete depending on its density grade, taking into account strength losses in the presence of surface-active substances, porosity, and strength characteristics of the matrix material. The values specified in GOST 25485-89 and calculated according to the proposed analytical laws and regulatory data are compared. The effect of the foaming reagent on the strength of the foam matrix was evaluated in accordance with GOST 30744-2001 on standard samples-beams 40x40x160 mm in size from the control cement test without additives and with additives of synthetic and protein foaming agents of different concentrations in the sealer (from 0.3 to 3%). The degree of influence of the foaming agent on the strength of the finished foam concrete prepared using classical technology was performed on samples-cubes of 100x100x100 mm in size according to GOST 10180-90. The article presents the results of a study of uniaxial compression strength calculated for cellular concrete depending on the density grades known from these regulatory documents and other sources. Analytical expressions for determining the strength calculated for cellular concrete with an average density of 300-900 kg/m3 are presented. The proposed approach, based on the assessment of the initial data – the strength class of the binder, porosity, matrix strength, type and concentration of the foaming agent-allows us to predict the final strength of foam concrete products of this average density. Their rational accounting will help in the production of construction products of the maximum possible strength at a given density. This will expand the use of foam concrete in construction.
Winter concrete: problems and solutions
Authors: Shlyakhtina T F , Ivankova E A , Popov N A
Published: May 2021

Monolithic construction in winter faces problems of concrete strength set at negative ambient temperature. In order to ensure the necessary temperature conditions for hardening concrete use different methods of heating structures. One of the most effective ways is to warm up using a heating wire. The tasks of stood concrete in winter conditions are multifactorial, and computer modeling can significantly improve the efficiency of work. The ELCUT software complex is a tool in solving such problems, based on the method of the final elements. On the example of a monolithic foundation slab, the process of hardening of concrete at the temperature of the coldest five-day and medium-winter in Bratsk was simulated. The calculation of the concrete strength set and the analysis of temperature fields, taking into account the requirements for crack resistance, has been made. Computer simulations allowed to pick up the parameters of laying the heating wire in the concrete.
Key indicators of quality control assurance in the quarterly development of residential buildings
Authors: Stepanova V S , Bazhakina M S
Published: May 2021

Ensuring the quality of construction of capital construction projects is one of the most important functions of the customer, contractor and other participants in the construction, which should be carried out at all stages of construction of residential buildings. Inadequate performance of their functions by construction participants can lead to a low quality of construction and installation work, a violation of the technology and organization of construction, and as a result, to a delay in construction.
Formation of a highly efficient wooden housing construction sector in Russia
Authors: Bezrukikh O A
Published: May 2021

The Russian government sets global strategic goals for increasing the volume of housing construction-mass multi-storey, multi-apartment and residential housing, creating a comfortable urban environment, comprehensive development of rural areas, construction of social infrastructure facilities in small towns and villages of the country, designated in the national projects “Health”, “Culture” and “Education”. The state assigns a key role in their implementation to modern wooden construction. Recently, many interesting projects have appeared in the field of wooden housing construction. There is a noticeable interest of the state in the development of this area, which is primarily due to the focus on the efficient use of the country’s forest resources, as well as the fact that wooden housing construction, due to the high degree of factory readiness of building elements and structures, creates products with high added value and the most transparent from the point of view of taxation, when compared with other areas in construction. Despite this, the potential of wooden construction is not fully disclosed, which does not allow to ensure their environmental friendliness, comfort and energy efficiency. The purpose of the article is to achieve high rates of individual housing construction through a combination of measures aimed at increasing its liquidity. The article analyzes the market of wooden housing construction in Russia, which allowed us to determine the promising construction technologies of the housing construction sector under consideration. The main properties of wood, its advantages and disadvantages are considered. It is determined that the development of industrial housing construction of individual residential buildings will allow not only to implement the tasks of national projects in Russia, but also increase the flow of investment in the construction of individual residential buildings using the industrial method, which will support enterprises that produce factory-made house sets. Based on this, the article contains recommendations for improving the quality of wooden construction products at all stages of the construction life cycle, the implementation of which will generate demand for wooden housing construction, ensuring the rational use of wood and high quality for consumers of products.
Integration of big data in the decision-making process in the real estate sector
Authors: Cheryshenko M S , Pomernyuk Yu Yu
Published: May 2021

We live in a time when the volume of data is growing at an unprecedented rate every day. Technical progress and the emergence of big data have transformed the development of all sectors. Although it came with its challenges it also created new opportunities. The emergence of Big Data and related analytics technologies led to changes in the business world. In today’s business processes, extracting genuine value form Big Data, and integrating it into the core decision-making strategy plays a vital role. Any company that wants to stay competitive in its business sector has to adopt to the changes. Data analytics is transforming the way companies do business by deriving value from large data sets. Real value from big data and integrating it into core solutions - strategy development is vital. The article studies the process of integration of big data into the decision-making process in the real estate sector. The authors examine the role of big data for decision-making and identify the importance of big data in various decision-making processes in the real estate sector. The article can be seen only as a brief introduction. The results of this study can be used for further analysis on this topic.
Investigation on the content of petroleum products in the surface run-off from the road pavements
Authors: Balabanov V B , Haptuhaev A V
Published: May 2021

Road transport is considered to be one of the leaders from the viewpoint of damage caused to the environment. One of the principal problems, which specialists encounter with in connection with exploitation of automobiles, is the discharge of highly contaminated surface wastewaters from highways onto the close ground territories and into the close water reservoirs. The objective of the present investigation presumed determination of the real content of oil products in the surface run-off waters from the surfaces of automobile roads. Within the frames of the present investigation, we studied the available experience in assessment of the content of pollutants in storm drain from the objects of transport infrastructure. The content of petroleum products in surface waste waters formed on highways was studied.
Resistance of basalt fiber to alkaline environment of hydrated Portland cement
Authors: Borovskikh I V , Khozin V G , Khokhryakov O V , Makarenko S V
Published: May 2021

The article shows a study of the effect of hydrated Portland cement, aggressive towards basalt fiber, and more aggressive saturated lime solution over time. The degree of destruction of basalt fiber over time has been established.
The field of application of road transport in the delivery of drinking water and wastewater disposal
Authors: Chupin V R , Moroz M V
Published: May 2021

Due to the uneven distribution of water resources across the territory of Russia, many settlements and even cities do not have their own sources of water supply and reservoirs, where treated wastewater could be discharged. Group and regional water supply and sanitation systems are being designed, built and developed to solve this problem. The length of such systems is hundreds and even thousands of kilometers. The construction and operation of such structures requires significant annual financial investments. Therefore, the choice of routes, the composition of structures, and especially the methods of transporting water and wastewater, justifying the location of water intakes and treatment facilities are relevant and require special attention and a feasibility study of design options. Based on the method of redundant design schemes, the paper proposes an integrated approach to optimize structures and methods of supplying water to consumers, transporting wastewater to treatment facilities by pipeline and road transport.
Hyperpressed ceramic products based on industrial waste
Authors: Rozina V E , Shestakov N I
Published: May 2021

The article discusses the features of the technology of production of ceramic products based on low-plastic clays and overburden. Physical and mechanical parameters of ceramic products obtained by hyperpressing with a pressure change from 10 to 100 MPa are determined. It is established that with an increase in the pressing pressure above 60 MPa, it is possible to obtain ceramic products with a compressive strength of up to 70 MPa and an average density of up to 2.1 g/cm3. The possibility of using high pressing pressures to produce high-strength ceramic bricks is justified. The results of the study of moisture loss during natural drying and physical and mechanical properties of raw products are presented.
Standard structures of road pavements for highways of the Baikal region
Authors: Slobodchikova N A , Stepanenko A A
Published: May 2021

A network of regional highways in the Russian Federation urgently needs good and cost-efficient road constructing materials. Obtaining such materials is possible by strengthening local soils with inorganic binders. For the purpose of efficient application of such materials in the process of structures roads and highways in the Baikal region it is necessary to develop standard structures, which take account of regional characteristics. The regulatory documents in force on the territory of the Russian Federation do not contain standard structures in which materials reinforced with inorganic binders are used. The paper discusses some results of investigation bound up with development of standard structures of road pavement using local soils of the Baikal region, which are reinforced with inorganic binders.
Analysis of the concept of the construction market and its segments in Russia
Authors: Arkhipkin O V , Cherutova M I , Skorobogatova Y A , Bovkun A S
Published: May 2021

The epidemic of the coronavirus COVID-19 and the introduction of restrictive measures in many industries have given a negative path for the construction industry. The State Duma of the Russian Federation has not yet approved the draft strategy for the innovative development of the construction industry in the Russian Federation. The construction industry is experiencing another stage of the crisis. This determines the importance of monitoring and analyzing the concepts of the construction market and its main segments, because they largely determine the development policy of the Russian construction industry.
On the issue of improving the accuracy of construction cost calculations at the pre-project stage
Authors: Dobysheva T V
Published: May 2021

The article deals with the issues of determining the cost of construction products on the territory of the RF at the pre-project stage. The results of the obtained calculations of the construction cost at the pre-project stage are analyzed using various methods. The disadvantages of determining the cost of construction using the enlarged collections of the CPS-2020 are revealed. Ways to improve the accuracy of construction cost calculations at the pre-project stage are proposed, in particular, by applying extrapolation formulas that are currently not available in the methodology for calculating construction costs based on enlarged collections. It is proved that the application of the proposed formulas significantly increases the accuracy of calculations, bringing the obtained values closer to the most accurate calculation of the construction cost – the result of the consolidated estimated calculation of the construction cost, compiled within the project documentation.
The strategy of regional development: cluster formation methods
Authors: Dorzhieva E L , Kirillova T K
Published: May 2021

The article discusses the cluster approach to the regional economic development. It describes the method of creating a spatially localized recreational cluster. The method for calculating the integral indicator of clustering has been improved. The indicators of recreational development have been added to the group of regional economic development indicators. To assess the correctness of the results, the integral indicator for assessing the regional socio-economic development has been calculated by the multifactor ranking method. It involves the calculation of the Euclidean metric, which shows the deviation of the integral indicator from the standard. The main risks of spatially localized recreational clusters have been identified.
Rolling verification of the performance of real estate investment funds
Authors: Gercekovich D A , Yu Gorbachevskaya E
Published: May 2021

Currently, there is an urgent need to develop an institutional rental housing market. It is an obvious fact that this issue cannot be resolved without the formation of available investment resources. This article discusses aspects of one of these promising forms – real estate investment funds. The article uses historical data on the dynamics of profitability of the 21st real estate fund for 2013 -2020 to test the method of assessing the risks of investing funds for potential investors – the method of sliding verification of groups of leaders synthesized using the “Yield-risk” model. The model is based on the basic principles of portfolio analysis. The results obtained indicate the suitability of the proposed method. Testing was carried out on current data from 2017-2020, which were not used to build the model. The constructed groups of leading funds demonstrate their continuity at all stages of rolling verification. The conducted correlation analysis showed a fairly close mutual correlation between the dynamics of profitability of the studied real estate funds, which significantly weakens by 2020. The proposed method can be used when making decisions about investing money in investment real estate, including rental housing of various categories.