bluuebunny/crossref_metadata_2025 huggingface dataset:
Are heavy metals in urban garden soils linked to vulnerable populations? A case study from Guelph, Canada
Authors: Montaño-López Fernando , Biswas Asim
Published: May 2021

With increasing population, there is growing concern for food security in urban areas. Though, urban gardening has gained popularity, several studies have found higher concentrations of contaminants in urban soils, especially heavy metals, often at toxic levels, which pose a potential risk for human health. Moreover, heavy metal polluted sites have been strongly associated with areas populated by low-income families, newcomers and racial minorities. In this study, heavy metals in the soils of community gardens in the city of Guelph, ON were examined as a case study and their relationship with vulnerable populations. We analyzed soil samples at two depths for a range of heavy metals and characterized their spatial patterns to see if they were related to disadvantaged communities. We estimated the pollution levels using two index-based approaches and assessed their potential risk for human health, although concentrations of most heavy metals were below the limits established by Canadian regulations, metals like Cd, Pb, Se and Zn exhibited a mild degree of pollution, whereas As exhibited a severe degree. Their association with vulnerable populations were weak, but hotspots were mainly located in low-income areas. This case study provides scientific evidence that could help to expand our understanding around the interconnection between pollution and poverty/racial inequality. Also the importance of generating strategies for the protection of human health and sustainable soil management practices in urban areas where food for human consumption is grown.
Rapid evolution of mammalian APLP1 as a synaptic adhesion molecule
Authors: Onodera Wataru , Asahi Toru , Sawamura Naoya
Published: May 2021

Amyloid precursor protein (APP) family members are involved in essential neuronal development including neurite outgrowth, neuronal migration and maturation of synapse and neuromuscular junction. Among the APP gene family members, amyloid precursor-like protein 1 (APLP1) is selectively expressed in neurons and has specialized functions during synaptogenesis. Although a potential role for APLP1 in neuronal evolution has been indicated, its precise evolutionary and functional contributions are unknown. This study shows the molecular evolution of the vertebrate APP family based on phylogenetic analysis, while contrasting the evolutionary differences within the APP family. Phylogenetic analysis showed 15 times higher substitution rate that is driven by positive selection at the stem branch of the mammalian APLP1, resulting in dissimilar protein sequences compared to APP/APLP2. Docking simulation identified one positively selected site in APLP1 that alters the heparin-binding site, which could affect its function, and dimerization rate. Furthermore, the evolutionary rate covariation between the mammalian APP family and synaptic adhesion molecules (SAMs) was confirmed, indicating that only APLP1 has evolved to gain synaptic adhesion property. Overall, our results suggest that the enhanced synaptogenesis property of APLP1 as one of the SAMs may have played a role in mammalian brain evolution.
The distributional properties of exemplars affect category learning and generalization
Authors: Carvalho Paulo F. , Chen Chi-hsin , Yu Chen
Published: May 2021

What we learn about the world is affected by the input we receive. Many extant category learning studies use uniform distributions as input in which each exemplar in a category is presented the same number of times. Another common assumption on input used in previous studies is that exemplars from the same category form a roughly normal distribution. However, recent corpus studies suggest that real-world category input tends to be organized around skewed distributions. We conducted three experiments to examine the distributional properties of the input on category learning and generalization. Across all studies, skewed input distributions resulted in broader generalization than normal input distributions. Uniform distributions also resulted in broader generalization than normal input distributions. Our results not only suggest that current category learning theories may underestimate category generalization but also challenge current theories to explain category learning in the real world with skewed, instead of the normal or uniform distributions often used in experimental studies.
Aging affects artemisinin synthesis in Artemisia annua
Authors: Li Jiao , Chu Xiao-Hui , Wang Xiao-Yu , Feng Bao-Min , Yu Zong-Xia
Published: May 2021

Artemisinin (ART) is the most effective component in malaria treatment, however, the extremely low content restricts its clinical application. Therefore, it is urgent to increase the yield of ART. ART gradually accumulates with aging, small RNA (sRNA) and transcriptome analysis were applied on the leaves of 2-week-old (2 w) and 3-month-old (3 m) A. annua respectively. Among all the annotated sRNAs, 125 were upregulated and 128 downregulated in the 3 m sample compared to the 2 w one. Whereas 2183 genes were upregulated and 2156 downregulated. Notably, the level of miR156 and several annotated miRNAs gradually decreased while SPLs increased. In addition, the genes on ART biosynthesis pathway were significantly upregulated including ADS, CYP71AV1, ADH1, DBR2 and ALDH1, and so were the positive transcription factors like AaERF1, AaORA and AaWRKY1 indicating that age influences the ART biosynthesis by activating the expression of the synthesizing genes as well as positive transcription factors. This study contributes to reveal the regulatory effects of age on ART biosynthesis both in sRNA and transcription levels.
Synthesis, structure, and properties of carbon/carbon composites artificial rib for chest wall reconstruction
Authors: Tan Zhoujian , Zhang Xiang , Ruan Jianming , Liao Jiqiao , Yu Fenglei , Xia Lihong , Wang Bin , Liang Chaoping
Published: May 2021

In this work, braided carbon fiber reinforced carbon matrix composites (3D-C/C composites) are prepared by chemical vapor infiltration process. Their composite structure, mechanical properties, biocompatibility, and in vivo experiments are investigated and compared with those of traditional 2.5D-C/C composites and titanium alloys TC4. The results show that 3D-C/C composites are composed of reinforced braided carbon fiber bundles and pyrolytic carbon matrix and provide 51% open pores with a size larger than 100 μm for tissue adhesion and growth. The Young’s modulus of 3D-C/C composites is about 5 GPa, much smaller than those of 2.5D-C/C composites and TC4, while close to the autogenous bone. 3D-C/C composites have a higher tensile strength (167 MPa) and larger elongation (5.0%) than 2.5D-C/C composites (81 MPa and 0.7%), and do not show obvious degradation after 1 × 106 cyclic tensile loading. The 3D-C/C composites display good biocompatibility and have almost no artifacts on CT imaging. The in vivo experiment reveals that 3D-C/C composites artificial ribs implanted in dogs do not show displacement or fracture in 1 year, and there are no obvious proliferation and inflammation in the soft tissues around 3D-C/C composites implant. Our findings demonstrate that 3D-C/C composites are suitable for chest wall reconstruction and present great potentials in artificial bones.
Models that combine transcriptomic with spatial protein information exceed the predictive value for either single modality
Authors: Vathiotis Ioannis A. , Yang Zhi , Reeves Jason , Toki Maria , Aung Thazin Nwe , Wong Pok Fai , Kluger Harriet , Syrigos Konstantinos N. , Warren Sarah , Rimm David L.
Published: May 2021

Immunotherapy has reshaped the field of cancer therapeutics but the population that benefits are small in many tumor types, warranting a companion diagnostic test. While immunohistochemistry (IHC) for programmed death-ligand 1 (PD-L1) or mismatch repair (MMR) and polymerase chain reaction (PCR) for microsatellite instability (MSI) are the only approved companion diagnostics others are under consideration. An optimal companion diagnostic test might combine the spatial information of IHC with the quantitative information from RNA expression profiling. Here, we show proof of concept for combination of spatially resolved protein information acquired by the NanoString GeoMx® Digital Spatial Profiler (DSP) with transcriptomic information from bulk mRNA gene expression acquired using NanoString nCounter® PanCancer IO 360™ panel on the same cohort of immunotherapy treated melanoma patients to create predictive models associated with clinical outcomes. We show that the combination of mRNA and spatially defined protein information can predict clinical outcomes more accurately (AUC 0.97) than either of these factors alone.
M/TiO2 (M = Fe, Co, Ni, Cu, Zn) catalysts for photocatalytic hydrogen production under UV and visible light irradiation
Authors: Díaz L. , Rodríguez V. D. , González-Rodríguez M. , Rodríguez-Castellón E. , Algarra M. , Núñez P. , Moretti E.
Published: May 2021

Cu/TiO2 photocatalysts can be considered a promising low-cost alternative to the well-known Pt/TiO2 system for hydrogen production under UV-Vis irradiation.
Immunomodulatory and antimicrobial non-mulberry Antheraea mylitta silk fibroin accelerates in vitro fibroblast repair and regeneration by protecting oxidative stress
Authors: Sen Sohini , Ghosh Shaunak , De Sayantan , Basak Piyali , Maurye Praveen , Jana Nandan Kumar , Mandal Tapan Kumar
Published: May 2021

Initially SF accelerated pro-inflammatory cytokines, restricted anti-inflammatory cytokines; later it regulated in reverse order. SF potentially eradicated ROS and promoted Ki-67 cellular regeneration whereas pristine PU could not.
Recent trends on burn wound care: hydrogel dressings and scaffolds
Authors: Yao Yingxia , Zhang Andi , Yuan Congshan , Chen Xiguang , Liu Ya
Published: May 2021

Biomaterial -based therapy in burn wound care and the roles and advantages of hydrogels.
Biomolecular l-tryptophan as a hole mediator anchored on g-C3N4 exhibits remarkably enhanced photocatalytic H2 evolution
Authors: Zhao Tan , Cheang Tuck-Yun , Chong Han-Bao , Ling Cong , Lu Xiao-Jie , Li Chen-Chuang , Fang Xiao-Xiang , Ma Liu-Bo , Wang Gang , Xu An-Wu
Published: May 2021

A novel g-C3N4-based composite coupled with levorotatory-tryptophan restrains the recombination of photogenerated holes and electrons, exhibiting enhanced photocatalytic H2 production.
Eosin Y-sensitized rose-like MoSx and CeVO4 construct a direct Z-scheme heterojunction for efficient photocatalytic hydrogen evolution
Authors: Jin Zhiliang , Li Hongying , Gong Haiming , Yang Kaicheng , Guo Qingjie
Published: May 2021

MoSx/CeVO4 was prepared by a simple hydrothermal method and a direct Z-scheme heterojunction was constructed. The existence of heterojunction provides a special transmission path for electron transfer between two materials.
A conversion and pseudocapacitance-featuring cost-effective perovskite fluoride KCuF3for advanced lithium-ion capacitors and lithium-dual-ion batteries
Authors: Huang Yuxi , Ding Rui , Xu Qilei , Shi Wei , Ying Danfeng , Huang Yongfa , Yan Tong , Tan Caini , Sun Xiujuan , Liu Enhui
Published: May 2021

A cost-effective perovskite fluoride KCuF3material has been introduced as an advanced anode for lithium-ion capacitors (LICs) and lithium-dual-ion batteries (Li-DIBs), showing a conversion mechanism and pseudocapacitive kinetics for Li ion storage.
A hollow Co9S8rod–acidified CNT–NiCoLDH composite providing excellent electrochemical performance in asymmetric supercapacitors
Authors: Sun Chao , Sun Li , Fan Kaifeng , Shi Yan , Gu Jialin , Lin Yifan , Hu Jingjing , Zhang Yihe
Published: May 2021

Co9S8hollow rods were wound with aCNTs and then compounded in flower like NiCoLDH to form a unique mosaic structure, providing sharply increased charge transport channels as electrodes for asymmetric supercapacitors.
Understanding the issues in monitoring the treatment effectiveness of constructed wetlands in urban areas – a case study in greater Melbourne, Australia
Authors: Yang Fujia , Gato-Trinidad Shirley , Hossain Iqbal
Published: May 2021

Assessing the effectiveness of stormwater treating wetlands is limited due to the lack of resources, guidance, motivation and appropriate maintenance.
Can T-carbon serve as a Li storage material and a Li battery anode?
Authors: Cheng Li-Rong , Lin Zheng-Zhe , Li Xi-Mei , Chen Xi
Published: May 2021

T-carbon is proposed as a Li storage material with a capacity three times that of graphite.
Does black phosphorus hold potential to overcome graphene oxide? A comparative review of their promising application for cancer therapy
Authors: Ruiz Amalia , Martín Cristina , Reina Giacomo
Published: May 2021

In this mini-review, we will critically compare the applications of NBP and GO in cancer therapy focusing on material functionalization, biodegradation by design, phototherapy and immunotherapy.
A photoacoustic Zn2+ sensor based on a merocyanine/xanthene-6-ol hybrid chromophore and its ratiometric imaging in mice
Authors: Fang Hongbao , Wang Chengjun , Chen Yuncong , Chen Zhongyan , Yao Shankun , Yang Shiping , Dong Lei , Guo Zijian , He Weijiang
Published: May 2021

HD-Zn was constructed for reversible ratiometric PA Zn2+ imaging in vivo. Zn2+ titration experiments together with a theoretical study suggests that Zn2+ chelation-induced ICT alteration in HD-Zn is responsible for its ratiometric PA sensing ability.
Polyoxometalate modified transparent metal selenide counter electrodes for high-efficiency bifacial dye-sensitized solar cells
Authors: Zhang Lu , Chen Weichao , Wang Ting , Li Yunjiang , Ma Chunhui , Zheng Yuxiao , Gong Jian
Published: May 2021

We present a facile one-step hydrothermal approach for the growth of PW11Co/Co0.85Se on a conductive glass substrate, which could be used as transparent CE in bifacial DSSCs with enhanced front and back efficiencies of 7.56% and 5.82%, respectively.
Development of phenazine-2,3-diol-based photosensitizers: effect of formyl groups on singlet oxygen generation
Authors: Ohira Kazuki , Imato Keiichi , Ooyama Yousuke
Published: May 2021

Phenazine-2,3-diol-based photosensitizers with different numbers of formyl groups were developed, and their photosensitizing ability to generate singlet oxygen was investigated.
Synthesis of 3-spirooxindole 3H-indoles through Rh(iii)-catalyzed [4 + 1] redox-neutral spirocyclization of N-aryl amidines with diazo oxindoles
Authors: Zhou Qianting , Song Xia , Zhang Xinying , Fan Xuesen
Published: May 2021

Presented herein is a novel synthesis of 3-spirooxindole 3H-indoles via the coupling and spirocyclization of N-aryl amidines with diazo oxindoles.
Straightforward supramolecular purification of C84 from a fullerene extract
Authors: Ubasart Ernest , García-Simón Cristina , Pujals Míriam , Asad Karam , Chronakis Nikos , Parella Teodor , Ribas Xavi
Published: May 2021

An efficient, one-step protocol for the enrichment of C84 (up to 86%) directly from a fullerene extract is reported, by utilizing a tetragonal prismatic nanocapsule with a suitable size and shape for selective encapsulation.
Facile synthesis of novel dopamine-modified glass fibers for improving alkali resistance of fibers and flexural strength of fiber-reinforced cement
Authors: Ma Pengfei , Xin Minglian , Zhang Yan , Ge Shenguang , Wang Dan , Jiang Congcong , Zhang Lina , Cheng Xin
Published: May 2021

In situ modification on fibers: in situ modification of self-polymerized dopamine on glass fibers was adjustably established. Relying on such nanomodification on the surface, a drastic enhancement of alkali resistance of glass fibers could be achieved.
Antimicrobial α-defensins as multi-target inhibitors against amyloid formation and microbial infection
Authors: Zhang Yanxian , Liu Yonglan , Tang Yijing , Zhang Dong , He Huacheng , Wu Jiang , Zheng Jie
Published: May 2021

We report a new “anti-amyloid and antimicrobial hypothesis” by discovering host-defense antimicrobial peptides of α-defensins containing β-sheet structures, which possess inhibition functions against amyloid aggregation and microbial infection.
Phosphite mediated asymmetric N to C migration for the synthesis of chiral heterocycles from primary amines
Authors: Rani Soniya , Dash Soumya Ranjan , Bera Asish , Alam Md Nirshad , Vanka Kumar , Maity Pradip
Published: May 2021

N-Alkylpyridinium salt of chiral amines undergoes phosphite mediated stereoretentive migrations to generate chiral alkylpyridines. The role of phosphite on reactivity and stereoselectivity were examined to achieve a catalytic asymmetric version.
The rational design of Ni3S2 nanosheets–Ag nanorods on Ni foam with improved hydrogen adsorption sites for the hydrogen evolution reaction
Authors: Liu Hai-Jun , Yu Wen-Li , Li Meng-Xuan , Dou Shu-Yue , Wang Fu-Li , Fan Ruo-Yao , Ma Yu , Zhou Yu-Lu , Chai Yong-Ming , Dong Bin
Published: May 2021

Heterostructures made of Ni3S2 nanosheets–Ag nanorods on Ni foam are rationally designed as efficient electrocatalysts for the HER under alkaline conditions.
Design and fabrication of polydopamine based superhydrophobic fabrics for efficient oil–water separation
Authors: Zhang Jixi , Zhang Ligui , Gong Xiao
Published: May 2021

Robust and durable superhydrophobic fabrics based on dopamine surface modification with efficient oil–water separation properties are reported.
A scalable strategy toward compliant tandem yarn-shaped supercapacitors with high voltage output
Authors: Zhang Juan , Xu Qingli , Qian Xiangyu , Wang Xinhou , Zhang Kun
Published: May 2021

Tandem YSSCs with high voltage output and suitable mechanical properties were simply assembled by interconnecting tens of units in series on a single PTFE filament, demonstrating good potential in practical on-body applications.
Cobalt sulfides constructed heterogeneous interfaces decorated on N,S-codoped carbon nanosheets as a highly efficient bifunctional oxygen electrocatalyst
Authors: Sun Changbin , Ding Jia , Wang Haozhi , Liu Jie , Han Xiaopeng , Deng Yida , Zhong Cheng , Hu Wenbin
Published: May 2021

The Co9S8/Co1−xS@NSC heterostructures have been prepared by a one-pot salt template-assisted pyrolysis procedure, which exhibit superior bifunctional oxygen electrocatalysis and zinc–air battery performances.
Magnetic assembly and manipulation of Janus photonic crystal supraparticles from a colloidal mixture of spheres and ellipsoids
Authors: Xiao Mengqi , Liu Jingjing , Chen Zhijie , Liu Wenxuan , Zhang Chengcheng , Yu Yingying , Li Chaoran , He Le
Published: May 2021

Janus photonic crystal supraparticles with novel structures and properties were magnetically assembled from a colloidal mixture of nonmagnetic spheres and magnetic ellipsoids.
Painting the green canvas: how pigments produce flower colours
Authors: Narbona Eduardo , del Valle José C. , Whittall Justen B.
Published: May 2021

Flowering plants are characterized by the production of striking flower colours and these colours are primarily caused by the accumulation of pigments in cells of the floral organs. The extraordinary array of colours displayed in flowers relies on four main pigment groups: chlorophylls, carotenoids, flavonoids and betalains. With thousands of different compounds, flavonoids are the most diverse and widespread pigment group. They include coloured anthocyanins, aurones and chalcones, as well as many flavonoid compounds such as flavones and flavonols that are invisible to humans, but visible to most pollinators since they absorb ultraviolet light (UV). Flowers may exhibit homogenous colours produced by only one type of pigment or extremely complex colour patterns caused by the accumulation of several types of pigments in the same or in different floral organs. Here, we review the ecological biochemistry of pigments affecting flower colour. We also present data of flower colour variation and provide future research directions guided by the physiological functions of floral pigments.
Flexible power control strategy for elliptical trajectory based dynamic voltage restorer during voltage sags
Authors: Li Peng , Wang Yi , Wang Can , Pan Xuewei , Lu Jinghang , Li Xue , Blaabjerg Frede
Published: May 2021

Dynamic voltage restorer (DVR) plays an essential role in achieving high‐quality voltage restoration in the distribution system. This paper presents an elliptical‐trajectory‐based approach to guarantee continuous power delivery by considering the active and reactive power limits during voltage sags. Besides, two parameters are proposed in the accurate mathematical analysis of current references. Thus, the control objective can be fulfilled by the flexible current injection strategy that combines a precise balance between the positive and negative sequences. The proposed control method can determine the required power injections by selecting the two proper values to support that the converter output current is smaller than the maximum rated value. Under the presented control, the maximum power limit and flexible power dispatch are combined together to develop four operation schemes. The main advantage is the smooth transition process during changes in the operation schemes and the disappearance of active and reactive power oscillations. Also, these four control states are applied to reveal the flexibility of the proposed designs. Finally, the hardware tests in a laboratory prototype are implemented to validate the feasibility of the proposed method.
SpheCow: Flexible dynamical models for galaxies and dark matter haloes
Authors: Baes Maarten , Camps Peter , Vandenbroucke Bert
Published: May 2021

Simple but flexible dynamical models are useful for many purposes, including serving as the starting point for more complex models or numerical simulations of galaxies, clusters, or dark matter haloes. We presentSpheCow, a new light-weight and flexible code that allows one to easily explore the structure and dynamics of any spherical model. Assuming an isotropic or Osipkov-Merritt anisotropic orbital structure, the code can automatically calculate the dynamical properties of any model with either an analytical density profile or an analytical surface density profile as starting point. We have extensively validatedSpheCowusing a combination of comparisons to analytical and high-precision numerical calculations, as well as the calculation of inverse formulae.SpheCowcontains readily usable implementations for many standard models, including the Plummer, Hernquist, NFW, Einasto, Sérsic, and Nuker models. The code is publicly available as a set of C++ routines and as a Python module, and it is designed to be easily extendable, in the sense that new models can be added in a straightforward way. We demonstrate this by adding two new families of models in which either the density slope or the surface density slope is described by an algebraic sigmoid function. We advocate the use of theSpheCowcode to investigate the full dynamical structure for models for which the distribution function cannot be expressed analytically and to explore a much wider range of models than is possible using analytical models alone.
Considering the temperature factor of hardening concrete in the construction of transport infrastructure facilities
Authors: Pulyaev Sergey , Pulyaev Ivan
Published: May 2021

Currently, there is a significant increase in personal and commercial road transport in the Russian Federation, which is why the issue of building new roads, bridges, tunnels, and other crossings is becoming more acute. Since often during the construction of these facilities, one of the main tasks is to minimize the construction period of the object, the process of intensifying production processes comes first. Based on the fact that the absolute leader in the use of reinforced concrete as the main building material, it is important and necessary to observe all the quality characteristics of this material both at the stage of laying the concrete mixture in the formwork, and in the process of maintaining the hardening concrete until the termination of heat-and-humidity care for it. In this regard, in order to optimize the temperature factor of hardening concrete in the construction of transport infrastructure facilities, it is necessary to provide measures at the design stage to consider the influence of the temperature gradient of hardening concrete on the operational properties of building structures. The article presents the main methods for considering the temperature factor of the hardening concrete of the constructed structures, developed by the authors of the work, the use of which will ensure the defect-free concreting of objects, including in an accelerated time.
Chemical composition of nanomodified cement stone
Authors: Grishina Anna , Korolev Evgenij
Published: May 2021

Improving the properties of cement building materials is possible with the use of modifiers, including nanoscale ones. Such nanomodifiers include hydrosilicates of zinc and copper. The increase in the performance characteristics of nanomodified cement composites is due to changes in the chemical composition of the resulting cement stone, in particular, an increase in the content of hydrosilicate structures. The chemical composition of the cement stone was studied by FTIR-spectroscopy. Colloidal solutions of zinc and copper hydrosilicates with known characteristics were used for the nanomodification of cement stone. It is shown that when using copper hydrosilicates synthesized at high concentrations of iron hydroxide, the concentration of amorphous silica does not significantly affect the composition of cement stone. However, with a decrease in the concentration of iron hydroxide, with an increase in the concentration of amorphous silica, the content of hydrosilicate structures increases. The use of nanoscale zinc hydrosilicates is more efficient than copper hydrosilicates. Their use makes it possible to increase the content of structures containing silicon-oxygen tetrahedra, submicrocrystalline calcium hydrosilicates of a tobermorite-like structure in cement stone, and the formation of ettringite is also noted. Thus, it was found that the use of zinc hydrosilicates as nanomodifiers for cement stone allows increasing the content of hydrosilicate structures in hydration products.
Improving the efficiency of anaerobic disposal of organic waste
Authors: Shcherbakov Vladimir , Pomogaeva Valentina , Shukina Tatyana , Chizhik Konstantin , Bazhenov Victor
Published: May 2021

Experimental studies on the decontamination and stabilization of sludge sites sediment with calcium oxide treated with disinfectant. The results of the research discovered that the sewage sludge of Voronezh City is safe and can be used as organic fertilizer for growing agricultural plants. Determination of the content of macro-elements of mineral nutrition in the soil and the reaction of its environment showed that the application of organic fertilizers in the form of sludge increases the amount of nitrate nitrogen, exchangeable potassium, mobile phosphorus in the soil compared to the non-fertilized sample. Contemporaneously, the mass fraction of impurities of toxic elements in the soil decreases when the sewage sludge is used as an organic-lime fertilizer.
Properties of sand concrete with recycled tyre polymer fibers
Authors: Larsen Oksana , Shvetsova Viktoria , Patsenko Ekaterina , Polozov Artyom
Published: May 2021

Disposal of tyre waste is a major environmental problem in all over of the world. It has been estimated that more than 1.5 billion tyres are produced annually and almost one million end their service life. More than 50% of them are accumulated on landfills. The tyre fiber can be added to the concrete mixture to improve not only the strength properties, but also the crack resistance of the composition. The use of recycled tire polymer fibers as reinforcement component is a perspective view on the development of dispersed concrete technology. In this research the main characteristics of the fiber and the technological characteristics of the concrete mixture are presented. The effect of the polymer fiber on strength and performance properties of sand concrete are shown. It was found that the optimal dosage of fiber is 1 kg/m3, the adding of the fiber reduces at the range 3.6% of slump of the concrete mixture. It was found that each 10 kg/m3of recycled polymer fiber reduce the density of samples by 4%. The addition of such amount of the polymer fiber reduces the compressive strength. The addition of 1 kg/m3 has the significant effect on the reduction of the compressive and flexural concrete strength with class B15, while the same characteristics of concrete with class B30 are higher. The results of this research allow to conclude that such fiber is suitable to use in concrete with class В30 and lower.
Heat-efficient ceramic products based on modified rice straw
Authors: Kodzoev Mukhamad-Basir , Isachenko Sergey , Rasulov Olimjon , Kaddo Maria
Published: May 2021

The current state of the building ceramics production is based on the following facts. Firstly, as a result of market conditions, the number of operating ceramics factories has significantly decreased. Secondly, considering the increase in the house construction rate due to the shift to new financing mechanisms, there has been an increase in the ceramic brick production by 2-3% since 2019. Growth opportunities are associated with higher thermal efficiency of ceramic products and masonry based thereon.

The research objective in this article was the development of compositions for wall heat-efficient ceramics based on loess low-grade loams with the use of rice straw as a burnout additive and, in particular, the determination of the optimal processed rice straw consumption. The scientific novelty of the research consisted in the development of a method for selecting the ceramic mixtures composition, optimizing the composition and substantiating the rice straw and rice straw ash influence on the ceramic mixtures and products properties.

Rice straw is introduced into clay masses at the preparation stage in an amount of 5-15% (by mass) of fluff rice straw, which burns out with burning temperature of 200-300°C and makes the mass porous, preventing shrinkage and forming ash containing up to 20% of amorphous silica. Carbonates in clay dissociate during firing, interacting with amorphous silica and forming various calcium silicates that strengthen the shard structure.
Integrated modifying zinc-containing additive for construction silicate compositions
Authors: Ivaschenko Yuri , Kochergina Maria , Pavlova Irina , Fomina Natalya
Published: May 2021

Sodium silicate binders are a promising binder base for obtaining effective granular thermal insulation materials. Increasing water resistance, first of all, will expand the scope of their application in construction. At the same time, the features of the modification of sodium silicate binders by compounds of polyvalent metals have not been fully studied, the interaction with which leads to the formation of hardly soluble silicates. The purpose of this work was to develop a modifying complex based on a zinc-containing compound - zinc acetate to increase the water resistance and thermal characteristics of the porous granular material. The proposed modifying additive is a complex consisting of zinc acetate and an organic alcohol solvent. It is shown that the properties of porous granular material can be controlled by changing the composition of the zinc acetate solvent. Qualitative and quantitative dependences of the properties of porous granules (strength, water resistance, density, thermal conductivity) on the type of zinc-containing solution and its content in the compositions have been obtained. The concept of the mechanism of formation of sparingly soluble complexes during the modification of sodium silicate binders with zinc-containing aqueous-alcoholic solutions has been developed. X-ray phase analysis showed that the sodium silicate system modified with an aqueous alcohol solution of zinc acetate, in contrast to an aqueous solution of zinc acetate, is completely in an amorphous state. We believe that compounds of the Zn2SiO4H2O, ZnSiO3 type are in the amorphous state. The obtained research results made it possible to determine the rational composition of granular heat-insulating material with increased operational and functional characteristics (ρ = 200-280 kg / m3, λ = 0.052-0.063 W / (m °C), R = 1.3-1.8 MPa, Kr = 0.89-0.92, W = 16- 18 %).
The efficiency of varying parameters when optimizing reinforced concrete structures
Authors: Tamrazyan Ashot , Alekseytsev Anatoly
Published: May 2021

The actual issue is considered related to the purpose of the type of variable parameters, their number and grouping of structural elements in the optimization of reinforced concrete structures. The genetic search algorithm is used to solve the problem of minimizing the cost of frame systems. The rate of convergence of the iterative procedure is taken as one of the criteria for the significance of the parameter when varying. The comparison of optimization results for a reinforced concrete beam and a frame is given. A conclusion is made about the expediency of varying parameters of different types and their ranking is performed from the standpoint of the goal function sensitivity to parameter changing.
Experience in the design and operation of retaining walls of overpasses of the Central Ring Road on the base with soil improvement by vibro stone columns
Authors: Rytov Sergey , Iovlev Ilya , Rytova Tatyana
Published: May 2021

Reinforced retaining walls were used on the overpasses of the Central Ring Road. To reduce the sedimentation of the base of these walls, to reduce the time of consolidation of the base, the transformation of soil properties by reinforcing vibro stone columns was used. In order to obtain an optimal result for the transformation of the properties of the base soils, increasing the reliability of the reinforced structures, comparative calculations were carried out with the variation of the parameters of the reinforcing elements. The method of quality control of the device vibro stone columns is improved.
Understanding the fall-related safety issues in concrete formwork
Authors: Chellappa Vigneshkumar , Ravindra Salve Urmi
Published: May 2021

The construction industry recorded high rates of fatalities and injuries due to falls at the workplace. Among other activities, concrete formwork tends to have more fatal falls. This study aims to understand the fall-related safety issues in the formwork lifecycle of construction projects. To achieve this, the process of formwork activities was mapped, and the safety risks associated with each activity were classified. Method development and risk identification focused on interviews with construction professionals involved in the construction of formwork and site observations of the formwork activities. The overall finding was that pouring, stripping, and erection activities have more issues related to falls. Future research is being carried out to assess the risks of falls from the construction experts’ views to prevent fall accidents in the future.
The problem of rationing escape routes in pre-trial detention centers
Authors: Parfenenko Aleksandr , Komrakov Artem
Published: May 2021

The article discusses the basic requirements for buildings and structures. The review of the scientific literature on fire safety revealed the lack of accounting for the working hours of pre-trial detention centers, as well as the influence of the employees of the institution. The existing risk assessment methodology is not applicable to such buildings, since the key factor in ensuring the safety of people is the time when the evacuation of people begins. The lack of standards and methods related to the risk assessment of buildings of pre-trial detention centers creates the need for large-scale experiments on the evacuation of people.
Non-disruptive method to decrease stresses in the web of the crane beam
Authors: Danilov Alexander , Tusnina Olga
Published: May 2021

Ensuring the required resource of the bearing capacity of the crane beams is one of the most urgent tasks from the point of view of the rational design. The approach proposed in this article is based on the principle of redistribution of the functions of the elements involved in the operation of the crane structure. Weak resistance to rotation of the top flange and the adjoining web zone is a critical disadvantage of a typical crane structure. Additional reinforce elements are proposed to eliminate the consequences of the influence of this disadvantage. At the same time, these reinforce elements practically do not perceive either the vertical or horizontal components of the crane load, preventing only the rotation of the top flange on the length between the beam stiffeners. Another feature is that no additional stress concentration zones are created either in the flange or in the web from welding or drilling holes. The article provides a comparative analysis of the stress-strain state of the crane beams based on the results of numerical calculations carried out with the use of ABAQUS software package. It is shown that the stresses in the upper zone of the beam web, reinforced by the proposed method, are up to 20% lower than in a conventional I-beam. However, despite the simplicity of the solution, the positive results of numerical analysis and the supposed manufacturability of the approach, it is undoubtedly necessary to conduct a series of full-scale experiments on already existing objects.
Determination of stress-strain properties of thawing soils in oedometer
Authors: Rabinovich Mikhail , Alekseeva Anastasia
Published: May 2021

Article presents relation of thawing coefficient (Ath) and compressibility coefficient during thawing (m) to the sampling depth and physical state of frozen soils in loams, typical for the Arctic region of the European part of Russia. Conclusions are drawn that help to predict thawing deformation of the tested soils according to their physical characteristics.
Influence of welding on aluminium alloy AW6082-T6 strength
Authors: Katanina Alla , Kornev Oleg , Shuvalov Aleksandr , Sokolova Eugenia
Published: May 2021

Comparison of welding influence on structural strength of Al-Mg-Si alloy (AW6082-T6), supplied with 10 mm thick sheets, is made. Within the research tension and impact tests of welding joints, made with argon-arc and friction stir welding, were carried out. During the research we observed the following: strength and plasticity decrease for welding joint zones, impact strength increase of weld metal in friction stir welding, welding defects influence on joint strength.
The use of FRP of increased thickness for strengthening structures
Authors: Simakov Oleg
Published: May 2021

The external reinforcement system based on carbon fiber has been used for decades to strengthen reinforced concrete elements. At the same time, it is impossible not to recognize that the existing calculation methods are largely based on empirical dependencies obtained from experimental studies. One of these issues is related to the application of the methodology for materials of heterogeneous origin-tapes and laminates. In general, the possibility of applying the calculation methods accepted in the norms for laminates of generally accepted thicknesses up to 1.6 mm is determined. The question related to the possibility of using laminates of greater thickness is not sufficiently studied. This article deals with the calculation of the reinforcement of the normal cross sections of the bent reinforced concrete elements with the reinforcement of laminates with a thickness of 5 mm.
Behavior of concrete beams reinforced with FRP during bending
Authors: Gorbunov Igor , Kakusha Vladimir
Published: May 2021

Article describes methods and results of experimental research for strain behavior, crack formation and fracture of concrete beams reinforced with fiber reinforced polymer (FRP) bars during bending moment action. 18 beams (3+3 series) reinforced with glass FRP (GFRP) and basalt (BFRP) 6, 10 and 14 mm in diameter were tested. Deflection in the middle of the beam, concrete and bars strain and ultrasonic transmission time for 4 routes were measured during tests besides visual inspection. Main crack formation occurred at 8-20% of the ultimate load for all beams. Crack formation was transition border to linear (elastic) straining at low bending stiffness. More than 15 times decrease in bending stiffness was seen for beam reinforced with two types of bars 6 mm in diameter compared to initial values. Existence of main cracks and major deflections is not allowed during design of bending elements. However small bending stiffness at linear elastic straining is a positive factor in case of «hard» loading and impact (pulsed) loading. It is possible to prevent structures collapse and people deaths at impact loading and cyclic «hard» loading by permitting crack formation in load bearing structures.
Effectiveness of fluid viscous damper for steel frame building subjected to earthquake load
Authors: Pham Thanh Binh , Vu Ngoc Quang
Published: May 2021

Since the appearance of the first modern multistories buildings, besides the demand of ensuring the bearing capacity, one of the urgent problems facing the engineer is to do how to design structure to ensure the requirements of normal use such as displacement, motion acceleration within permissible limits. There exist many methods to reduce these response of structure under lateral load. Among these, using fluid viscous damper (FVD) is one of the most applied equipment because of its simplicity. This paper presents the examination of eight-story steel frame structure subjected to seismic load. The FVD system is defined in Etabs with link properties. In each story, four dampers are located in each direction of plan, with two on each side of the center of stiffness of the story. The time history analysis was conducted to study the structure subjected to seimic load collected from the function library of program Etabs. The effect of FVD system was determined by the dynamic response of the building and displacement indexes such as maximum displacement of roof, story drift ratio. The results show that, all the dynamic response characters of structure were decreased significantly when providing the FVD to it.
Contractual relations of participants in the life cycle of a construction project
Authors: Gusakova Еlena , Pavlov Aleksandr
Published: May 2021

Contracts accompany all stages of the life cycle of a construction object. The contractual relationship should ensure a balance of production and economic interests of numerous participants in the construction project and stakeholders of the project. When a project is being implemented by several dozen contractors, it is difficult to achieve a balance of interests, the content of contracts is often multidirectional or contradicts each other. In order to systematize the relationships of the project participants, contractual relations in the construction industry and the functions of the subjects of contracts are analyzed. The structure of contracts in construction, based on the cash flow of the project, is proposed. Allocated 6 groups of contracts: agreements concluded by the investor; contracts concluded by the developer, employer; contract agreements; contracts for the supply of goods and the provision of services; collective and individual labor contracts. The main features of each group of agreements and the functions of the subjects of agreements in Russia and abroad are considered. It is shown that, as part of the theory of project management, it is relevant and expedient to develop a section on the structure of contracts, planning a contract campaign and support for a complex of project contracts. It is proposed to develop contracts and think through the contractual terms of the project agreed, under the leadership of the project management team.
Control modules in the “Intelligent building” system
Authors: Alyoshintsev Andrey , Mokrova Natalia , Sak Alexander
Published: May 2021

The relevance of the article consists on the use of telemetry control modules to organize the uninterrupted operation for dispatching service, including remote work. Thanks to telemetric means of dispatching control and management of the conditions of water supply facilities, the process is reaching a new qualitative level. The functionality of the water intake unit has been significantly improved as a result of the introduction of a telemetry and telecontrol system in the form of separate technological modules. The developed modules provide additional functions for water quality control, including residual chlorine, accounting for a number of random pollution factors in addition to the route technology of the dispatching system; remote control of executive mechanisms with the possibility of automatic control; self- diagnostics of the software and hardware complex, as well as planning of preventive and repair work of engineering systems.

The results of water quality on-line monitoring by using a telemetry module in the chlorination room automatically providing the optimal ratio of chlorine added to the water are presented.
Formation of local temperature regime in the room: personal ventilation system
Authors: Rymarov Andrey , Havanov Pavel , Titkov Dmitri
Published: May 2021

The peculiarities of a person’s metabolism are related to the state of health, age, and other personality traits, which determines the need for a personal value of the ambient air temperature. Individualization of work and recreation of people requires the creation of local temperature zones in the room with the air temperature necessary for a particular person, which will increase labor productivity, reduce morbidity, since the stress of the human thermoregulation system will be minimal. In addition, the personalization of the microclimate in the workplace in the room with the creation of local temperature zones will allow you not to waste heat and electricity where it is not needed, creating additional opportunities for energy saving potential in the premises of the building. The article deals with the personalization of the operation of the ventilation system in the room with the formation of vertical conical air jets coming from the ceiling of the room to the workplace, considering the requirements of regulatory documents for the air velocity in the working area of the room.
Method of determining the optimal version of the piezometer of gas distribution networks of medium and high pressure
Authors: Zhila Viktor , Klochko Aleksey
Published: May 2021

The article deals with the issues of determining the optimal type of piezometric pressure graph in high-and medium-pressure gas pipelines in the design of gas distribution networks. Along with the most commonly used ways to reduce the cost of building gas distribution networks by finding the optimal configuration of gas pipelines, which give a great economic and environmental effect, it is necessary to rationally use the pressure drop provided to the network. This step in engineering practice allows you to additionally get money savings. The use of various schemes for supplying consumers with gas in cities and villages also has a great economic effect, but modern equipment allows you to make the transition to a single-stage scheme of gas distribution networks for cities. When designing gas distribution networks, the available pressure drop can be used by implementing various technical solutions, but the correct choice of pressures in the nodal points contributes to an economic effect. The designed configuration of the gas distribution network with the adopted type of piezometric graph can ensure reliable operation for a long time. The results obtained are recommended for use in the design of gas distribution networks of cities, other settlements and distribution networks of industrial enterprises