bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary Cilia Exhibit Mechanosensitivity to Cyclic Tensile Strain and Lineage-Dependent Expression in Adipose-Derived Stem Cells
Authors: Bodle Josephine , Hamouda Mehdi S. , Cai Shaobo , Williams Ramey B. , Bernacki Susan H. , Loboa Elizabeth G.
Published: May 2019

Non-motile primary cilia are dynamic cellular sensory structures and are expressed in adipose-derived stem cells (ASCs). We have previously shown that primary cilia are involved in chemically-induced osteogenic differentiation of human ASC (hASCs) in vitro. Further, we have reported that 10% cyclic tensile strain (1 Hz, 4 hours/day) enhances hASC osteogenesis. We hypothesize that primary cilia respond to cyclic tensile strain in a lineage dependent manner and that their mechanosensitivity may regulate the dynamics of signaling pathways localized to the cilium. We found that hASC morphology, cilia length and cilia conformation varied in response to culture in complete growth, osteogenic differentiation, or adipogenic differentiation medium, with the longest cilia expressed in adipogenically differentiating cells. Further, we show that cyclic tensile strain both enhances osteogenic differentiation of hASCs while it suppresses adipogenic differentiation as evidenced by upregulation of RUNX2 gene expression and downregulation of PPARG and IGF-1, respectively. This study demonstrates that hASC primary cilia exhibit mechanosensitivity to cyclic tensile strain and lineage-dependent expression, which may in part regulate signaling pathways localized to the primary cilium during the differentiation process. We highlight the importance of the primary cilium structure in mechanosensing and lineage specification and surmise that this structure may be a novel target in manipulating hASC for in tissue engineering applications.
Anephrogenic phenotype induced by SALL1 gene knockout in pigs
Authors: Watanabe Masahito , Nakano Kazuaki , Uchikura Ayuko , Matsunari Hitomi , Yashima Sayaka , Umeyama Kazuhiro , Takayanagi Shuko , Sakuma Tetsushi , Yamamoto Takashi , Morita Sumiyo , Horii Takuro , Hatada Izuho , Nishinakamura Ryuichi , Nakauchi Hiromitsu , Nagashima Hiroshi
Published: May 2019

To combat organ shortage in transplantation medicine, a novel strategy has been proposed to generate human organs from exogenous pluripotent stem cells utilizing the developmental mechanisms of pig embryos/foetuses. Genetically modified pigs missing specific organs are key elements in this strategy. In this study, we demonstrate the feasibility of using a genome-editing approach to generate anephrogenic foetuses in a genetically engineered pig model. SALL1 knockout (KO) was successfully induced by injecting genome-editing molecules into the cytoplasm of pig zygotes, which generated the anephrogenic phenotype. Extinguished SALL1 expression and marked dysgenesis of nephron structures were observed in the rudimentary kidney tissue of SALL1-KO foetuses. Biallelic KO mutations of the target gene induced nephrogenic defects; however, biallelic mutations involving small in-frame deletions did not induce the anephrogenic phenotype. Through production of F1 progeny from mutant founder pigs, we identified mutations that could reliably induce the anephrogenic phenotype and hence established a line of fertile SALL1-mutant pigs. Our study lays important technical groundwork for the realization of human kidney regeneration through the use of an empty developmental niche in pig foetuses.
NMR metabolome of Borrelia burgdorferi in vitro and in vivo in mice
Authors: Glader Otto , Puljula Elina , Jokioja Johanna , Karonen Maarit , Sinkkonen Jari , Hytönen Jukka
Published: May 2019

Lyme borreliosis (LB), caused by bacteria of the Borrelia burgdorferi sensu lato (Borrelia) species, is the most common tick-borne infection in the northern hemisphere. LB diagnostics is based on clinical evaluation of the patient and on laboratory testing, where the main method is the detection of Borrelia specific antibodies in patient samples. There are, however, shortcomings in the current serology based LB diagnostics, especially its inability to differentiate ongoing infection from a previously treated one. Identification of specific biomarkers of diseases is a growing application of metabolomics. One of the main methods of metabolomics is nuclear magnetic resonance (NMR) spectroscopy. In the present study, our aim was to analyze whether Borrelia growth in vitro and infection in vivo in mice causes specific metabolite differences, and whether NMR can be used to detect them. For this purpose, we performed NMR analyses of in vitro culture medium samples, and of serum and urine samples of Borrelia infected and control mice. The results show, that there were significant differences in the concentrations of several amino acids, energy metabolites and aromatic compounds between Borrelia culture and control media, and between infected and control mouse serum and urine samples. For example, the concentration of L-phenylalanine increases in the Borrelia growth medium and in serum of infected mice, whereas the concentrations of allantoin and trigonelline decrease in the urine of infected mice. Therefore, we conclude that Borrelia infection causes measurable metabolome differences in vitro and in Borrelia infected mouse serum and urine samples, and that these can be detected with NMR.
Mycotoxins: Contamination, Control and Analyses
Authors: Moran Kara , O'Kennedy Richard
Published: May 2019

Mycotoxins are toxic secondary metabolites produced by fungi and moulds known to contaminate a broad range of food commodities and animal feed. These toxins have detrimental effects on human and animal health. Mycotoxins pose a global problem due to their widespread presence and this is aggravated by our lack of understanding of multi-mycotoxin pervasiveness and effects on health. However, our ability to tackle the mycotoxin problem is greatly strengthened by the development of sophisticated technologies which now permit the detection and identification of many mycotoxins in multiple food commodities. Additionally, inexpensive and rapid test methods which permit the direct analysis of mycotoxins in the field are emerging, which allow decisions on food safety to be made locally at the point of testing. Combining technological advances in mycotoxin testing with studies that provide more knowledge on mycotoxic effects in local populations will provide an all-encompassing understanding of the true mycotoxin impact on humans globally. This approach can inform local policy-making, to ensure that appropriate measures and regulations are implemented to protect populations most at risk from mycotoxins prevalent in their locality.
Optical and Acoustic Label-free Instrumentation for Molecular Detection with a Focus on Food
Authors: Kuncová-Kallio J. , Auer S. , Spehar A. , Qu J. H. , Spasic D. , Lammertyn J.
Published: May 2019

In this chapter, we focus on label-free techniques suitable for the detection of analytes in food samples. We demonstrate the capabilities of such techniques on optics-based (surface plasmon resonance, SPR) and acoustic-based (quartz crystal microbalance, QCM) devices using immunoassays. Label-free techniques can be miniaturised and thus can be brought closer to the point of use, such as a farm, a field, a storage space, a shipyard, a factory gate or even a restaurant. First, the working principles of traditional SPR and of a QCM are introduced. The basic terminology is briefly covered and common technical considerations, including the required surface chemistry, limit of detection, ability to multiplex, ability to work with crude samples and complexity of liquid handling, are discussed. Secondly, commercial instruments are described including Biacore, ForteBio and Q-Sense. In addition, newer technical variations such as fibre-optic SPR (FOX diagnostics), imaging SPR (Horiba), multiparametric SPR (BioNavis), and a solidly mounted resonator (BioMensio) are discussed. An overview of different commercialised optic and acoustic label-free techniques and their suitability for food analysis is included. Since most of the instruments on the market focus on more generic assays, the third part of this chapter reviews assays for food analysis that are currently being developed. The fourth and final section provides an outlook on the future of instrumentation in this field.
Applications of Recent Developments in Microfluidics for Rapid Analysis of Food Safety and Quality
Authors: Soares Ruben R. G. , Chu Virginia , Conde João P.
Published: May 2019

Immunoassays performed on the nanolitre scale using microfluidics allow a reduction in reagent volumes and assay times, providing, by design, a high degree of control of mass transport and reaction kinetics. Furthermore, the development of rapid microfluidic prototyping technologies including soft lithography, 3D-printing and micromilling have resulted in a dramatic increase in the reporting of innovative analytic strategies integrating sample preparation, immunodetection and signal transduction in miniaturized portable devices. This degree of integration and automation aims to allow the routine monitoring of target molecules by non-specialized personnel. This is currently in high demand by regulatory agencies, producers and consumers within the scope of food safety and quality. This chapter summarizes recent trends in miniaturized immunoassays, discusses the fundamental concepts of immunoassays performed in microfluidic channels and provides an overview of current design strategies for miniaturization, with an emphasis on the integration of optical, electrochemical and label-free methods to provide signal transduction. In addition, examples of these assays in the context of food safety and quality, namely in the detection of low molecular weight organic and inorganic contaminants, protein toxins or allergens and foodborne pathogens, are described and discussed in detail.
Detection of Food Taints and Contaminants Using Novel Engineered Antibodies
Authors: Leivo J. , Lamminmäki U.
Published: May 2019

This chapter describes technologies and methods widely employed in the development and engineering of antibodies utilized in food diagnostics. Immunoassays have been considered as the golden standard for the simple, high-throughput screening of contaminants from a variety of matrices. Cost-efficiency, in combination with increasingly efficacious tools for obtaining antibodies with high specificity and affinity, has led to the widespread use of immunoassays for the routine detection of various food contaminants. As the quality of the immunoassay is primarily dependent on the binding properties, such as affinity and specificity, of the antibody used to recognize the contaminating compound, it is often feasible to modify these properties to enhance the performance of the assay. The rapid development of directed antibody engineering technologies in the past three decades has facilitated the generation of assays with novel specificity for high-throughput analysis of foodstuffs. More recently, antibodies with novel specificity have been utilized to develop high-performance analytical methods which have expanded the limits of traditional immunoassays, in terms of sensitivity and number of detectable contaminants.
Fabricating an intelligent cell-like nano-prodrug via hierarchical self-assembly based on the DNA skeleton for suppressing lung metastasis of breast cancer
Authors: Li Yunyan , Yan Tong , Chang Wenya , Cao Chongjiang , Deng Dawei
Published: May 2019

A new intelligent cell-like nanostructure is designed for suppressing lung metastasis of breast cancer.
Inhibition of bleomycin-induced pulmonary fibrosis in mice by the novel peptide EZY-1 purified from Eucheuma
Authors: Yu Huajun , Zhang Zhao , Huang Hui , Wang Yajun , Lin Biyun , Wu Shang , Ma Jingyao , Chen Baoan , He Zhan , Wu Jun , Zhao Zuguo , Zhang Haitao
Published: May 2019

For the first time, a new 16-amino-acid peptide was isolated from Eucheuma, an edible seaweed, and named EZY-1.
Palladium catalysed [3 + 2]-annulation reaction of vinylcyclopropanes with pentafulvenes: synthesis of polysubstituted spiro[4,4]nona-6,8-dienes
Authors: Zhang Si-Chen , Lei Xin-Xin , Yang Yong-jian , Luo Yong-Chun , Zhang Huan-Huan , Xu Peng-Fei
Published: May 2019

A novel palladium catalysed [3 + 2]-annulation reaction of vinylcyclopropanes with pentafulvenes has been developed for the synthesis of spiro[4,4]nona-6,8-dienes.
Doping engineering of conductive polymer hydrogels and their application in advanced sensor technologies
Authors: Ma Zhong , Shi Wen , Yan Ke , Pan Lijia , Yu Guihua
Published: May 2019

This perspective article reviews recent progress in rational synthesis of conductive polymer hydrogels utilizing doping principles and their applications in advanced sensor technologies.
Nickel-catalyzed decarbonylation of N-acylated N-heteroarenes
Authors: Morioka Toshifumi , Nakatani Syun , Sakamoto Yuki , Kodama Takuya , Ogoshi Sensuke , Chatani Naoto , Tobisu Mamoru
Published: May 2019

Nickel-catalyzed decarbonylation of N-acylated N-heteroarenes is developed, allowing aromatic acids to serve as an aryl source in arylation of NH-heteroarenes.
Switched capacitors 9‐level module (SC9LM) with reduced device count for multilevel DC to AC power conversion
Authors: Bhatnagar Pallavee , Agrawal Rekha , Kumar Dewangan Niraj , Jain Sanjay K. , Kumar Gupta Krishna
Published: May 2019

Switched capacitors (SCs)‐based modules are being increasingly used for multilevel DC to AC power conversion, especially for low input voltage applications. Many of these topologies operate in two stages involving H‐bridge switches, which endure high‐voltage stress. The SC 9‐level module (SC9LM) presented here operates in a single stage with one DC source and two capacitors. In addition, the peak inverse voltage of all power switches is confined to the voltage of the input DC source. The proposed 9‐level module ensures a reduced number of power switches. In addition, with appropriate utilisation of states, two of the eleven switches in the module operate at fundamental switching frequency, thereby minimising the switching losses. A single SC9LM achieves a voltage gain of two. The proposed module is validated through circuit analysis followed by simulation and experimental results.
Propagation loss and apparent conductivity models for through‐the‐earth communication in sedimentary soil
Authors: Pena Carreno Josua D. , Noll Barreto Andre , Braga Judson
Published: May 2019

Much of the channel modelling found in the literature for through‐the‐earth communication is based on deterministic formulations that consider few homogeneous layers of soil. However, due to the great variation in the properties of the soil, especially of its electrical conductivity, it is very difficult to generalise channel characterisation with such models. Some empirical models are used to identify apparent conductivity at specific sites in order to determine the propagation loss at these sites at any time. However, the use of these models is limited to the few frequencies used in the reference measurements. This study aims to statistically characterise magnetic field attenuation in underground coal mines. The authors use the Monte Carlo method based on electromagnetic simulations, using the finite element method. The simulations allowed empirical modelling, resulting in optimal operating frequency, propagation loss and apparent electrical conductivity statistics, especially for transmissions at the optimal frequency of each channel.
City brain: practice of large‐scale artificial intelligence in the real world
Authors: Zhang Jianfeng , Hua Xian‐Sheng , Huang Jianqiang , Shen Xu , Chen Jingyuan , Zhou Qin , Fu Zhihang , Zhao Yiru
Published: May 2019

A city is an aggregate of a huge amount of heterogeneous data. However, extracting meaningful values from that data remains a challenge. City Brain is an end‐to‐end system whose goal is to glean irreplaceable values from big city data, specifically from videos, with the assistance of rapidly evolving artificial intelligence technologies and fast‐growing computing capacity. From cognition to optimisation, to decision‐making, from search to prediction and ultimately, to intervention, City Brain improves the way to manage the city, as well as the way to live in it. In this study, the authors introduce current practices of the City Brain platform in a few cities in China, including what they can do to achieve the goal and make it a reality. Then they focus on the system overview and key technical details of each component of the City Brain system, from cognition to intervention. Lastly, they present a few deployment cases of City Brain in various cities in China.
Data modelling of converters for the automation and monitoring of MTDC grids
Authors: Roy Gaurav Kumar , Hu Jingxin , Sadu Abhinav , Ponci Ferdinanda , Monti Antonello , De Doncker Rik W.
Published: May 2019

Multi‐terminal DC (MTDC) grids based on voltage source converters (VSCs) are a promising option to integrate the increasing share of generation from the distributed energy resources (DERs) both in the transmission and distribution grids. However, with the broader use of VSCs for the transmission and distribution grid, there is an absence of a standardised data model for the VSC. In this work, the authors propose an IEC 61850 based data model for VSCs and an existing IEC 61850 model is extended for the dual‐active bridge (DAB) converter as an interlink between various DC terminals and the modular multilevel converter (MMC). Furthermore, a generic data modelling guideline is proposed for intelligent electronic devices (IEDs), which are responsible for the interoperability among converters in the MTDC grid. The implementation of the real‐time monitoring system of a hybrid AC‐DC MTDC grid with the proposed IED is presented as an exemplary case. Through experimental tests of this MTDC grid, it is shown that the proposed IED meets the latency requirements for P2 through P6 class of monitoring, protection, and control applications according to the IEC 61850 standard. The automation architecture presented in this work is also validated for interoperability within the MTDC grid.
Space vector PWM technique for a two‐level asymmetrical six‐phase drive
Authors: Ariff Engku Ahmad Rafiqi Bin Engku , Dordevic Obrad
Published: May 2019

A space vector pulse‐width modulation (PWM) technique for a two‐level asymmetrical six‐phase drive is proposed for the first time in this study. The PWM technique is developed based on the modified vector space decomposition approach. The details regarding the process of choosing the switching sequences and the calculation of dwell times are presented. The PWM technique is verified through simulation using PLECSsoftware and is further validated experimentally. Obtained results show the validity of the proposed PWM technique.
Improved rotor position determination for a sensorless star‐connected PMSM drive using Direct Flux Control
Authors: Schuhmacher Klaus , Grasso Emanuele , Nienhaus Matthias
Published: May 2019

A technique for driving a star‐connected PMSM without a position or speed sensor, which is known in the literature as Direct Flux Control (DFC), is described here. This technique is based on voltage measurements at the machine star point and can work even at very low speeds including standstill. The underlying principle of this technique is outlined and an improved position estimation algorithm allowing the exact reconstruction of the direction of maximum inductance is presented. The DFC technique is implemented on a microcontroller board and experimental validation is conducted on a PMSM both for quasi‐static characterisation and for open‐loop driving.
Determination of Regularities in the Development of Intermodal Hubs’ Planning Structure in «Smart» Cities
Authors: Vlasov Denis , Terekhova Anna
Published: May 2019

This article is an attempt to determine regularities in the development of transport and transfer hubs. One of the components of the “smart city” concept is the “smart transport”. The development of the transport system of a locality is one of the cornerstones for sustainable development of the urban territory, creating comfortable environment for human activities. The transport and transfer hub is the reference point of interaction between the urban environment and the transport infrastructure. When elaborating urban planning documentation for transfer hubs, special focus shall be made on the creation of comfortable and safe environment using the Transit Oriented Development (TOD) principles. At present, in Russia, the baseline document for territorial planning, which determines the limit parameters of the planned territory development, is the planning design. In Moscow and Moscow region, audacious transfer hub development programs have been adopted. Still, the regulatory and procedural framework for transfer hub planning is currently at the stage of elaboration. The goal of this study is to ascertain regularities between relevant and anticipated features of transfer hubs, based on approved hub plans in Moscow region. In particular, to reveal the dependence between the sizes of commercial areas making part of a hub, and the passenger traffic volume. The study uses the statistical method of regression analysis, which allows determining the function between dependent and independent variables. The model obtained can subsequently be used to calculate the limit parameters of the hub territory development, both at the stage of creating the hub development concept, and at the planning stage, to make well-grounded decisions as to limit parameters of the development.
The basic cycle of reorganization of construction
Authors: Kotov Yegor , Chulkov Vitaly
Published: May 2019

Reorganization is one of the fundamental processes of development of modern society. The infographic model of the reorganization cycle, also known as the “development wheel”, allows us to divide development of this process into four stages: settlement, disorganization, reorganization and co-organization. These stages have been researched on by numerous Russian and foreign researchers. In the sphere of construction, the most interesting is the restructuring, which has a special relevance at the present stage of development of the Russian Federation and requires creative approaches, models and methods of scientific research of vision of this important branch of economy. In this article, the model of reorganization process is structured with use of the theory of multipoint logic and the practice of infographic modeling, possible impacts and interactions leading to well-defined and formalized results are considered. Models of loading the interactions of individual components of the model of reorganization by control actions and the results obtained therewith have been developed.
Indicators of the effectiveness of self-healing asphalt concrete
Authors: Inozemtcev Sergey , Korolev Evgeniy
Published: May 2019

In the article, indicators reflecting the degree of efficiency of the self-healing technology being developed are proposed the degree of restoration of the operational state of the structure (degree of self-healing); the speed of the process of restoring the operational state of the structure (self-healing rate); durability operational status after self-healing; timeliness of initiation of the self-healing process. Indicators of the effectiveness of self-healing technology are justified by using the Pavement Condition Index (PCI).
Experimental research of structural organization of heat-insulating structural building materials for energy efficient buildings
Authors: Shaumarov Said , Adilkhodjaev Anvar , Kondrazhenko Valeriy
Published: May 2019

The article presents the results of research to determine the porosity of cellular concrete with different volume mass and strength by the method of “image analysis”. A photo-optical method of cellular concrete structure estimation is developed. The dependence of porosity and strength of the samples on the fractal dimension of the cellular concrete structure is obtained.
Technical and economic efficiency of materials using 3D-printing in construction on the example of high-strength lightweight fiber-reinforced concrete
Authors: Inozemtcev Aleksandr , Duong Thanh Qui
Published: May 2019

The technology of 3D printing in construction causes great interest by increasing the speed and accuracy of building structures, reducing labor costs, construction waste and risks to human health. Today, the principles of 3D-printing actually are interpretations of the existing monolithic or prefabricated technology. This requires the development of high-performance materials for the extrusion of functional structures. The paper shows the example of the effectiveness application of high-strength lightweight fiber-reinforced concrete with a complex of structural and thermal insulation properties in 3D-printing technology. It has been established that the use of high-strength lightweight fiber-reinforced concrete for 3D-printing provides an increase in the useful space by 1.1...5.4 %, a reduction in the material consumption of wall structures by 6.1...19.1 % and a reduction in the number of machine hours by 29.6...37.4 %. The total technical and economic efficiency of using such a material for a standard or optimized wall section is 30.8...50.4 %.
Nonlinear Deformation of Flexible Orthotropic Shells of Variable Thickness in an Unsteady Magnetic Field
Authors: Abdullaev Zafar , Mirzaev Sayibdjan , Mavlanov Sobir
Published: May 2019

The analysis of the stress state of a flexible orthotropic shell under the influence of a time-varying mechanical force and a time-varying external electric current is performed, taking into account the mechanical and electromagnetic orthotropy. The effect of thickness on the stress-strain state of the orthotropic shell is investigated. The results obtained indicate the influence of thickness on the deformation of the shell and the need to take this factor into account in the design schemes.
Finite element analysis of three-layer concrete beam with composite reinforcement
Authors: Vu Dinh Tho , Korol Elena , Kustikova Yuliya , Nguyen Huy Hoang
Published: May 2019

Reinforced concrete structures play an increasing important role in civil and industrial construction, along with the technology of new concrete materials and their calculation theories. In order to improve the crack resistance of three-layer reinforced concrete (3L-RC) beams with the middle layer of lightweight concrete (LWC) material, the method of using polymer bars in place of steel bars is applied. In this study, the behavior of 3L-RC beams with steel bars and glass fiber reinforced polymer (GFRP) bars is simulated and analyzed by ANSYS software (base on the finite element analysis). The simulation of reinforced concrete (RC) beam work on computer software is a modern method, which allows to input many mechanical, physical properties of materials and geometric parameters of 3L-RC beams. The results of the samples beam analysis showed that the cracking resistance of 3L-RC beams with GFRP bars have been enhanced more than twice compared to 3L-RC beams with steel bars. Numerical modeling allows comparison between the obtained results and building theoretical dependences in a wide range of specified parameters in sectional construction of multilayer reinforced concrete elements. This would limit the number of actual test samples, increase the efficiency of experiments.
Porous formation process of granules from man-triggered raw materials
Authors: Miryuk Olga
Published: May 2019

The results of studies of porous structure formation in a granular glass mixture are presented. Raw mixes were prepared from glass cullet, waste of magnetite ores dressing and liquid glass. The reason for adding of magnetite ores waste to the glass mixture was the information on chemical and mineral composition, results of studies of thermal transformations of waste. The rationale for adding of 20 – 30% of magnetite ores waste into the raw mix is confirmed by lowering the bloating temperature and increasing granules porosity. The effect of pyrite mineral on structural transformations in a glass mixture has been studied for the first time. It was revealed that the presence of pyrite up to 10% in the glass mixture intensifies swelling at lower temperatures. A method for preparing a molding mixture is proposed, which ensures the formation of highly porous granules with equal distribution of cells in the structure. The method involves mechanical activation of mixture of glass cullet and magnetite ores waste by grinding in a vibratory mill and subsequent portion-wise introduction of the activated mixture into liquid glass. A complex of technological methods allows obtaining porous granules with a packed density of 300 kg/m3 at a temperature of 825°C.
Parameters of the constitutive model of geomaterials formed with the use of DSM dry technology
Authors: Jendrysik Klaudia , Pachnicz Michał , Dudziński Paweł
Published: May 2019

Numerical modelling of geomaterials is always complex due to the variability of parameters within the soil massif (created in the natural geological processes) and the orthotropy caused by this. In the case of the soil substrate modification with the use of hydraulic binders, this issue is complicated even more due to the fact the degree of mixing can be differentiated for various areas, while in the dry mixing technology, it is additionally differentiated with the depth of consolidation stress. Additional factor that makes it difficult to predict the behaviour of stabilised soil is the possible content of organic parts. Due to the development of substrate reinforcement technology, as well as the growing market for such works, a need emerged to provide parameters of the numerical model for various materials or, at least, to provide a method for reverse analysis on the basis of available data. This paper presents an example of calibration of the selected numerical model (through parameter selection of this model) based on the conducted examinations of cubic sample in the conditions of uniaxial compression. The results of laboratory tests, reverse analysis in the numerical model with a pre-selected strength hypothesis and finally, the recommendations for selection of the model in calculations of real structure on a reinforced substrate, are demonstrated.
Reduction of mechanical interactions with the use of a rubber composite
Authors: Palacz Przemysław , Major Maciej , Adamczyk Izabela
Published: May 2019

The paper presents the results of research on the reduction of mechanical interactions of the composite produced from components resulting from the recycling of used car tires and plastic bottles (i.e. polyethylene terephthalate, colloquially called PET). Composite samples for testing were made with three thicknesses of mixtures rubber granules and PET flakes. The whole was joined together with an epoxy resin and formed into the shape of discs, which were then subjected to mechanical interactions to determine the damping properties depending on the thickness of the considered samples. The samples were subjected to evaluation on the author’s measuring stand. Obtained results of the research indicated that the developed composite well suppresses mechanical interactions resulting from dynamic interactions involving vibrations or vibrations in the analyzed frequency range. The developed composite can be used as a contribution to use in building materials that reduce mechanical interactions.
Modeling the colloidal dispersions: flocculation kinetics though particle dynamics
Authors: Smirnov Vladimir , Korolev Evgenij
Published: May 2019

The problem of stability of colloids recently begins to attract extra attention in construction materials science. This is due to numerous attempts to employ different kind of nanoscale modifiers for production of building materials with enhanced operational properties. Problems of stability and coagulation in colloidal dispersions are studied for several decades, and numerous results were already obtained within framework of Smoluchowski coagulation theory. In the present work we have performed numerical study of the flocculation process and compared the results with well-known ones. It was shown that even for complex pairwise potential the kinetics of number density for isolated particles is not very different from the kinetics which corresponds to constant coagulation kernel. However, for number density of many-particle aggregates we have observed number of peculiarities, including semi-periodic behavior.
Effective complex hydrophobizators for self-cleaning facade materials
Authors: Bruyako Mikhail , Ivashchenko Natalya , Dobrina Kristina , Moshnikov Mikhail
Published: May 2019

In the work presented here, we present the research results of the effect of self-cleaning of surfaces. The methods of its achievement such as photocatalytic and the method of hydrophobization are considered. The known methods for determining the contact angle of wetting are used. An installation for generating a low-temperature nonequilibrium plasma was used to modify a fine aggregate. The contact angles of wetting obtained as a result of the use of various formulations of hydrophobizing suspensions are determined experimentally. A modification of the quartz filling matter was also carried out. Experiments have confirmed the technical effectiveness of hydrophobisers and the enhancement of their properties when dispersed fillers are used. Even higher values of wetting contact angle were achieved using a plasma-modified filling matter.
Ultralight large grain porous material - expanded obsidian
Authors: Safaryan Artsruni , Sargsyan Tamara , Kalantaryan Marine , Melyan Hripsime
Published: May 2019

In the production of crushed stone, lithoidal pumice and perlite sand, it is advisable to separate and segregate the obsidian. Wherein, the separated obsidian is converted into production waste. By the expansion of obsidian it is possible to obtain an ultralight large grain porous material and thereby solve environmental issues - to dispose of waste products. The expansion of volcanic glass (obsidian) occurs due to gases, primary (magmatic) and secondary (hydraulic) water, which is located in the pores. During the expansion, under heat treatment, the gases expand about 4 ... 5 times in the pores, which contributes the expansion. Expanded obsidian can be used as a filler for lightweight concrete. Obsidian is expanded at temperatures of 1050-115°C. The lowest average density of 200 - 350 kg / m3 (in a piece) is obtained by heat treatment of obsidian with a particle size of 5 to 20 mm for a duration of 3-10 minutes. Depending on the requirements for lightweight aggregates, by adjusting the firing temperature and duration, it is possible to obtain expanded obsidian with the necessary physical and mechanical properties. It is revealed that more durable concretes are obtained with cement consumption of 350 ... 380 kg. Depending on the average density of lightweight concrete 400 .. 1350 kg/m3, the compressive strength is 0.2 ... 16,9 MPa. Light monolithic products with improved characteristics of heat resistance and thermistance, having an average density of 180-200 kg/m3, compressive strength of 1.2–1.5 MPa, frost resistance of 25 cycles, after which the strength changes to 1.0–1.3 MPa, heat resistance to 800–850°C, and thermistance to 600–650°C. By the thermal conductivity coefficient determination it was possible to reveal that in the temperature range of 20-60°C, the thermal conductivity coefficient changes by 0.002 W/mK, i.e. from 0.044 to 0.046 w/mK. Thus, the obtained monolithic blocks can be very successfully used as heat-insulating materials, which will retain their properties throughout the operation of the facilities. The requirements for mechanical strength and decorative properties for sound-absorbing materials compared to thermal insulating materials are higher, since they are used for internal linings. Thus, the obtained monolithic blocks can be very successfully used as heat-insulating materials, which will retain their properties throughout the operation of the facilities.
Water absorption of wood-polymer composites of savewood
Authors: Matseevich Tatyana , Matseevich Andrey , Askadskii Andrey
Published: May 2019

The materials based on wood-polymer composites (WPC) in the form of decking boards are produced, in which wood filler is partially replaced by mineral one. WPC materials manufactured by Savewood using a matrix polymer of polyvinyl chloride (PVC) have good mechanical properties, low abrasion and satisfactory resistance to climatic influences. However, they have relatively high water absorption, the task of reducing which is relevant not only in Russia, but also in other countries where there are constructions of facilities operating in outdoor environmental conditions. The modification of such materials in this work was carried out by replacing part of the wood filler with the mineral filler, which is CaCO3 (chalk). Partial replacement of wood flour with mineral filler resulted in a marked reduction in swelling from 1.25 to 0.01%. In this case, the modulus of elasticity is increased from 2260 to 2880 MPa, tensile strength from 30.5 to values of 16.7 ÷ 32 MPa. The specific impact strength varies from 8.90 to 7.74 kJ/m2. The optimal ratio of wood and mineral fillers is 60/40%.
On degeneracy of dispersive waves at the bulk wave velocities
Authors: Ilyashenko Alla , Kuznetsov Sergey
Published: May 2019

Degeneracy of the linear dispersion wave equation at the phase velocities coinciding with the bulk wave velocities is observed and analysed. Spectral analysis of Pochhammer – Chree equation is performed. The corrected analytical solutions for components of the displacement fields are constructed, accounting degeneracy of the secular equations and the corresponding solutions.
Seismic barriers: theory and numerical simulations
Authors: Bratov Vladimir , Ilyashenko Alla , Morozov Nikita , Rashidov Tursunbai
Published: May 2019

The basic idea of a seismic barrier is to protect an area occupied by a building or a group of buildings from seismic waves. Depending on the nature of seismic waves that are the most probable in a specific region, different kinds of seismic barriers are suggested. For example, vertical barriers resembling a wall in a soil can protect from Rayleigh and bulk waves. The FEM simulation reveals that to be effective, such a barrier should be (i) composed of layers with contrast physical properties allowing “trapping” of the wave energy inside some of the layers, and (ii) depth of the barrier should be comparable or greater than the considered seismic wavelength.
DIC (Digital Image Correlation) method in the research of RC beams strengthened with PBO-FRCM materials
Authors: Marcinczak Dorota , Trapko Tomasz
Published: May 2019

The article presents tests of a reinforced concrete beam strengthened in a shear with PBO-FRCM composite materials. Measurement of the deformation of the composite was carried out using two methods - with strain gauges and the optical DIC method (Digital Image Correlation). The DIC method consists in taking a series of photographs of the tested object before and during loading. The surface of the tested element must have randomly spaced spots that are applied to the object before measurement. During the study, the cameras monitor the shifting of spots against each other, which in comparison to the reference image before loading gives information about strains and stresses of the tested element. Measurements of deformation of composite materials using strain gauges are difficult to clearly analyse, because the strain gauge is in a specific, limited place, which does not correspond to the work of the entire composite. In addition, the strain gauge tends to break at the place of crack. The article discusses this problem by presenting the results of deformation of PBO-FRCM composite meshes measured in two mentioned ways, their comparison and discussion of results.
Modifying composition of plastering mortar for the purpose of enhancing fire resistance of building structures by means of silicate additives
Authors: Levashov Nikita , Akulova Marina , Sokolova Yulia
Published: May 2019

The present paper deals with modifying composition of plastering mortar for the purpose of enhancing fire resistance of building structures by means of silicate additives. Interaction of soluble water glass with cement binder elongates the initiation of setting time and reduces the time of final setting that could be explained by the opposed action of each component. One of the components facilitates the increase in the mobility of the mortar while the other, as opposed, is fastening rapidly. The optimum choice of the mixing ratio in the mortar would enhance both physical-mechanical and thermal properties.
Quality assurance program of a nuclear facility
Authors: Leybman Dmitriy , Khripko Tatiana
Published: May 2019

Quality Assurance Program (QAP, Program) is a standard, which regulates and coordinates activity, as well as determines quality assurance policy regarding services rendered and construction works conducted on nuclear infrastructure facilities. The Program must comply with the requirements of federal rules and regulations in the field of nuclear power engineering. The present QAP is available to all organisation employees carrying out works and rendering services during construction, reconstruction and major repairs of nuclear facilities as well as to experts conducting works and rendering services on a contract basis. The QAP implementation analysis and the evaluation of its results is conducted through internal audits. The implementation of the quality assurance program is provided through the following principles:

– the responsibility for quality assurance when conducting actual works and rendering services is imposed upon the task performer;

– precise segregation of duties and responsibilities between all contractors;

– regular control of compliance with regulations and developer’s requirements, as well as accurate documentation of the monitoring results;

– systematic update tracking for all official regulations and norms;

– the quality assurance methods incorporate the classification of equipment, systems and installation in terms of their impact on safety of nuclear facilities approved by official rules and regulations in the atomic energy sector.
Simulation of the System of Repairs of Apartment Buildings
Authors: Sokova Serafima , Kalinin Vladimir
Published: May 2019

the main issue of the study is the problem of improving the efficiency of the housing sector. The current state system does not ensure the proper efficiency of the housing stock, which is increasingly manifested in the growing gap between the cost of operation of apartment buildings, aimed at ensuring the quality of their functioning and the real state of this quality. In recent years, numerous regulatory documents have been adopted to ensure the normal maintenance of buildings, but a comprehensive understanding of the relationship of various activities with technical and economic solutions, in most cases, has an empirical nature, not confirmed by a strict analytical justification. The purpose of the study is a systematic integrated approach to solving problems to improve the efficiency of maintenance of housing using the proposed mathematical apparatus, which allows you to objectively, fully and accurately assess the relationship of economic and technical indicators. All total socially significant economic indicators of operational measures can be the basis of legislative regulation in the industry. Conclusions: criteria for assessing the effective and safe operation of buildings, optimal for residents of apartment buildings and management companies serving these houses.
Impact of configuration errors on the dynamic oscillation absorbers effectiveness of different masses on the seismic resistance of bridges
Authors: Shermuxamedov Ulugbek , Shaumarov Said
Published: May 2019

Analyzes existing known solutions for dynamic damping oscillations of bridges in earthquakes. Substantiates the impact of errors settings the two-mass systems on the efficiency of dynamic dampers of different masses (small, large and commensurate). Based on the obtained of optimal parameters were built isolines depending reduce the displacement of the main mass of the setting on the stiffness and damping for different masses. The estimates obtained allow to simplify essentially the task of designing seismic devices for bridges.
Geoecological assessment methods of the radiation hazard of the use of rocks in the building materials industry
Authors: Buzina Daria , Engovatov Igor
Published: May 2019

The production of human activity has led to the formation of technogenic radiation background, which is formed in its habitat due to initially distributed in the structures of the earth, particularly in rocks, “eternal” natural radionuclides (NRN). In its turn, rocks are the main raw material for building materials and products from them. Natural radionuclides are a source of radiation hazard to humans and their habitats throughout the entire chain of production and use of building materials for the construction of residential, administrative and industrial buildings. In order to reduce the factors of the negative impact of man-made radiation background on a person it is possible on the basis of studies of the radiation characteristics of building materials and raw materials for their manufacture, to identify sources of NRN in the chain from rocks to industrial production. In turn, the completeness and validity of the results is possible only on the basis of a comprehensive geo-environmental assessment of the radiation hazard characteristics of building materials and raw materials for their manufacture, which will reduce the negative impact on the ecology of the human environment through the use of “radiation-friendly” materials.
The influence of the solar radiation heat input into the room on the level of energy-efficient thermal protection of the building
Authors: Malyavina Elena , Frolova Anastasya
Published: May 2019

The task of increasing the energy efficiency of external enclosing structures is often considered as the need to increase their heat transfer resistance. At the same time, the main indicator of this efficiency is the heat consumption reduction for heating of the buildings having high thermal protection. Despite the fact that Russia is a rather cold country with a long heating period in most of its territory, the lack of accounting the cold consumption in warm period of the year leads to wrong understanding by the specialists of the energy expediency of the building thermal protection level. In today’s world, more and more buildings, which have been built, house the civil technologies with high heat emissions, i.e. administrative and office, entertainment, training, shopping and other buildings. These buildings require high energy consumption for cooling, which is often necessary even during the heating period. Taking into account the heat input from the solar radiation with variable intensity throughout the year, the thermal protection level is subject to significant corrections. This is due to the fact that often the cooling of the room is required during the periods when the outdoor temperature is below the maximum allowable room temperature. During these periods, the enhanced thermal protection is an obstacle to the natural heat outflow from the premises. The calculations showed that the higher is the solar radiation heat input, the smaller is the part of energetically feasible buildings according to the basic norms prescribed by the SP 50.13330.2012. And although the sanitary and hygienic requirements show no reasons of the building heat insulation from the energy point of view, the conclusions about the profitability of the building insulation with a reduced basic resistance to heat transfer of walls and coatings of the building are economically significant.