bluuebunny/crossref_metadata_2025 huggingface dataset:
Biogeochemical aspects of humic substances and silicate rocks transformation during freezing-thawing
Authors: Kondratyeva L. М. , Andreeva D. V. , Golubeva Е. М. , Litvinenko Z. N.
Published: December 2024

In the northern regions, as a result of seasonal temperature changes, cyclic thawing and freezing of soils and rocks occurs, which is accompanied by dangerous natural phenomena, including landslides. Special conditions arise on the mountain slopes of many reservoirs due to fluctuations of water levels and the interaction of humified waters with rocks. The paper presents the results of an experimental study of the biotransformation of sodium humate (SH) and changes in the microstructure of the surface of silicate rock that is part of the body of the Bureya landslide under various conditions of cyclic freezing-thawing (CFT). Freezing of samples was carried out at a temperature of –18 °C, and thawing at different temperature ranges (+4 °C and +23 °C). The role of biogenic factor was played by 4 strains of microorganisms isolated from the surface and bottom layers of water in the Bureiskoe Reservoir above and below the landslide body. The nature of the biotransformation of SH during CFT was studied by spectral methods at different wavelengths (254 nm, 275 nm, 465 nm). Analysis of the composition of water-soluble forms of chemical elements in an aqueous environment during rock destruction was carried out with use of the ICP-MS method, and changes in the microstructure of its surface with use of scanning electron microscopy. It was found that the transformation of aromatic component of SH occurred most active. After CFT, the strain Actinomyces sp. 45 VD, isolated from bottom layers of water, showed maximum activity at a thawing temperature of +4 °C in relation to SH and leaching of elements from rock (Al, Ca, Mg, Mn). Its activity was comparable to the intensity of leaching of elements by a natural microbial consortium of non-sterile rock. For comparison, we used rocks subjected to CFT in deionized water; in this case, the content of water-soluble forms of many chemical elements (Fe, Ni, Cu, Zn, As, Mo, Ag, Cd, Tl, Bi, As) was below the detection limits of the device (0.001). High biogeochemical activity of Actinomyces sp. 45 VD is confirmed by analysis of SEM-images of the microstructure of the silicate rock surface and the formation of a wide variety of isomorphic biominerals.
Geochemistry and age of paleoproterozoic metavolcanoic and metasedimentary rocks of the Don terrane of the Volga-Don orogen
Authors: Terentiev R. А. , Savko К. А. , Korish Е. H. , Chervyakovskaya М. V.
Published: December 2024

The Don terrane, which is extensively reworked by metamorphism and granitoid intrusions, is part of the Volga–Don orogen stretching along the eastern margin of the Sarmatian segment of the East European Craton. The terrane consists of gneiss-granites of the Pavlovsk complex, metavolcanic rocks, ranging from basaltic andesites to dacites (amphibolites and gneisses), and metasedimentary rocks (marbles and calc-silicate rocks) of the Don Group. The volcanic rocks are typically enriched in LILE and LREE and show negative HFSE anomalies, indicating fluid-assisted melting of the mantle wedge in a subduction zone. The Nd isotopic composition (εNd2200 = –1.2 to +3.4, model age 2180–2550 Ma) and Hf isotopic composition (εHf = –4.3 to +3.3, model age 2290–2640 Ma) indicate an enriched mantle or a mixed crustal–mantle source of the parental melts of the volcanics and a juvenile source for sediments of the Don Group. The U–Pb zircon metamorphic age of the gneisses and amphibolites is 2047 ± 7 Ma, and that of the thermal effect of the granitoid batholith on the host rocks is 2060 ± 4 Ma. According to isotope geochemical and geochronological data, the Don Group is underlain by Archean rocks, contains Archean detrital zircons, but the age of this group is no older than 2300 Ma. A facies and age analogue of the Don Group is the Temryuk Formation of the Central Azov Group of the Ukrainian shield. In the Paleoproterozoic, the eastern margin of Sarmatia was likely a continental arc, which was nearly coeval with the island arc–backarc basin system of the Losevo Group.
Gold in pyrite: thermodynamic model of socrystallization in chloride fluids
Authors: Prokofiev V. Yu. , Akinfiev N. N. , Bortnikov N. S.
Published: December 2024

A thermodynamic description of gold-bearing pyrite as a substitution solid solution is proposed depending on external conditions and gold content in the fluid. The model is based on experimental data of the synthetic pyrite grown in hydrothermal chloride solutions in the presence of metallic gold. The proposed model makes it possible to estimate the upper limit of gold content in pyrite. The thermodynamic model of gold-bearing pyrite was verified by modeling the process of formation of mineral associations of gold ores of the Darasun and Talatui deposits by chloride aqueous fluids in an integrated fluid-magmatic system of the Darasun ore field. Previously it was revealed that the average gold content in pyrite from the Darasun and Talatui deposits, intergrown with native gold, does not exceed 1 ppm, while synthetic pyrite grown in equilibrium with metallic gold under similar conditions contains 10–150 ppm of gold. This contradiction does not allow explaining the formation of gold ores of the Darasun ore field by its direct crystallization from hydrothermal fluid. A possible explanation is the presence of an additional stage of ore transformation, in which recrystallization of sulfides occurred with gold undersaturated solutions. It was shown that a decrease in gold concentration in the mineral-forming fluid below the saturation limit should lead to a synchronous decrease in the gold concentration in the resulting pyrite. The calculated values of gold concentration in model pyrite make it possible to estimate gold concentrations in mineral-forming chloride fluids at different stages of the formation of the Darasun ore field deposits at a known temperature. It has been shown that natural gold-bearing pyrite from various gold deposits was formed mainly from chloride fluids undersaturated to gold.
Expression of Prolactin Axis Genes in the Brain, Gills and Kidneys of the Three-Spined Stickleback G. Aculeatus L.: Dependency on Freshwater Adaptation and Sex
Authors: Pavlova N. S. , Neretina T. V. , Smirnova O. V.
Published: December 2024

The dependence of prolactin gene (Prl1) expression on sex in the brain and its receptors (PrlRa and PrlRb) in the brain, kidneys, gills, and intestine of the three-spined stickleback (Gasterosteus aculeatus L.) was studied in the context of freshwater adaptation. Males and females of the marine morph were adapted to freshwater for 72 hours, and the expression levels of Prl1 in the brain and PrlRa and PrlRb in the examined organs were assessed using RT-PCR. In seawater, no sex differences in Prl1 gene expression in the brain were observed; however, after freshwater adaptation, significant sex differences were detected due to increased Prl1 expression in females. In the brains of females, PrlRa gene expression was significantly lower in seawater compared to males but increased significantly after freshwater adaptation, eliminating sex differences. PrlRb gene expression in the brain increased significantly in females following freshwater adaptation. In the kidneys, no sex differences in PrlRa gene expression were found in either seawater or freshwater, although expression significantly decreased after freshwater adaptation in both sexes. PrlRb gene expression in the kidneys showed no sex differences in seawater but did so under freshwater conditions due to a significant increase in females and a decrease in males. In the gills, the expression of PrlRa and PrlRb genes was independent of both sex and salinity. In the intestine, neither sex nor salinity influenced the expression of the PrlRa gene. PrlRb gene expression in the intestine showed no sex differences and decreased in both sexes after transitioning to freshwater. It is concluded that the osmoregulatory function of prolactin's dependence on sex is manifested in the sex differences in the expression of the prolactin gene itself and in the sensitization of the brain and osmoregulatory organs to it during freshwater adaptation.
Zoobenthos of the freezing water bodies of the “Medvezh`i ostrova” Nature Reserve, East Siberian Sea
Authors: Potyutko O. M. , Shelokhovskaya L. V.
Published: December 2024

While monitoring the Polar bear in the “Medvezh`i ostrova” (= Bears’ Islands) Nature Reserve in October 2023, a number of mainland water bodies were surveyed: the lakes “Nesolyonoe” and “Unnamed”, the Krestovaya River, the “Unnamed” watercourse on Chetiryokhstolbovyi Island, as well as the sea bay of Kolyma Bay, all in the East Siberian Sea. Representatives of zoobenthos were found in each of the water bodies studied, but the fauna was not very diverse. A total of only 7 species of benthic invertebrates were revealed in the surveyed water bodies of the Bears’ Islands Nature Reserve, of which 3 species were found in sea water: Pacifoculodes pallidus (G. O. Sars 1892) (Amphipoda), Yoldiella nana (M. Sars 1865) (Bivalvia), and Enchytraeus albidus Henle 1838 (Oligochaeta). In the water bodies feeding the Galgavaam River, 2 species from the family Chironomidae and 3 species of eurytopic Oligochaeta were recorded. Their abundance ranges from 0.20 to 1.70 thousand ind./m2 and 0.10 to 3.70 g/m2 biomass in freshwater bodies, vs not exceeding 0.60 thousand ind./m2 and 1.90 g/m2 biomass in the sea. Seasonal cohorts are formed there, 37% of which are merohydrobionts (Сhironomidae) and amphibiotic Оligochaeta, and 13% each are neritic amphipods and bivalves. The formation of seasonal cohorts is determined by a short growing season and an extended ice formation on island and mainland watercourses and reservoirs.
Metamorphosis of the central nervous system in Habrobracon hebetor (Hymenoptera, Braconidae)
Authors: Veko E. N. , Makarova А. А. , Polilov А. А.
Published: December 2024

The structure of the central nervous system (CNS) of Habrobracon hebetor Say 1836 during the development from prepupa to imago was studied using histological methods and three-dimensional computer modeling. The metamorphosis of the CNS in H. hebetor largely coincides with the previously described changes in related groups of Hymenoptera. During development, the thoracic and abdominal ganglia of the nerve cord converge, the concentration of which reaches a maximum by the imago. The most noticeable changes in the CNS occur at the pupa I stage, when a sharp increase in the volumes of the cell cortex and neuropil in the CNS ganglia, an increase in the relative volume of the ganglia and an increase in the size of nerve cells are observed. The increase in the cell cortex of the ganglia is followed by its decrease by the imago stage, while the volume of the neuropil is significantly increased by the time the adult individual appears. An increase in the volumes of the key neuropil centers occurs throughout development from prepupa to imago. After a rapid increase in the size of nerve cells at the beginning of pupal development, it is decreased, with the average size of nerve cells in the imago being the same as in the prepupa. The number of nerve cells during pupal development is first increased, vs decreased at the imaginal stage, but not as much as in miniature Hymenoptera.
Elastic properties of the cell surface and metabolic profile of an embryonic primary mixed culture of hippocampal neurons under conditions of P2X3 receptor blockade
Authors: Zelentsova A. S. , Shmigerova V. S. , Stepenko Y. V. , Skorkina M. Yu. , Deykin A. V.
Published: December 2024

P2X3-receptors localized in the hippocampus participate in the transmission of excitation and the formation of synaptic plasticity underlying learning and memory. P2X3-receptors are of great importance in the occurrence of neuropathic pain in epilepsy, acute and inflammatory pain of various genesis and localization as well as in the activation and growth of nerves after traumatic brain injury. The aim of the study was to study the elastic properties of the surface and the metabolic profile of neurons in an embryonic primary mixed hippocampal culture under P2X3-receptor blockade. The study was performed on a primary mixed culture of hippocampal neurons obtained from CD1 mice on the 18th day of gestation (E18). The highly selective blocker 5-(5-iodo-2-isopropyl-4-methoxyphenoxy)pyrimidine-2.4-diamine monochloride salt was selected as a P2X3-receptor blocker. To assess the elastic properties of neurons Young's modulus that characterizes the rigidity of the cell surface was measured. Measurements on an atomic force microscope applying a load in 25 local areas of the cell surface were performed. At each point, the force curves of the cantilever approach and retraction were recorded with subsequent calculation of Young's modulus. The metabolic profile of the neuroglial culture in Energy Phenotype test on a Seahorse HS mini cell metabolism analyzer (USA) was studied. The Young's modulus of the cell surface of neurons in the control was in the range from 6.8 ± 0.1 to 9.7 ± 0.2 kPa, and under the action of the P2X3-receptor blocker in the range from 3.1 ± 0.1 kPa to 8.5 ± 0.1 kPa. Under the conditions of P2X3-receptor blockade on the 5th day of differentiation the Young's modulus of the cell surface was reduced by 62% (p 0.05), on the 8th day it increased by 22% (p 0.05) and by the 11th day it decreased by 16.7% (p 0.05) compared to the control. Aerobic respiration was characteristic of the embryonic hippocampal culture both in the control and with the P2X3-receptor blockade. Consequently, the blockade of the P2X3-receptor did not affect the metabolic profile of the E18 hippocampal culture. The obtained data indicate the direct participation of the P2X3-receptor in the formation of biomechanical properties of the cell surface in the processes of differentiation and signal transduction. It is possible, that the blockade of the P2X3-receptor will be one of the promising molecular targets that can reduce neuronal damage in brain injuries, neuroinflammation, hypoxia, and epilepsy. In addition, the study of the P2X3-receptor blockade can expand the fundamental understanding of the role of the purinergic signaling system in the formation of complex neuronal morphology at early stages of embryonic development under conditions of rapid excitatory signal transmission mediated by the ATP molecule.
Inverse Filtration Problem of Multiparticle Suspension
Authors: Kuzmina Liudmila , Osipov Yuri
Published: December 2024

The problems of filtration of suspensions in porous media, which are an integral part of underground hydromechanics, are solved when designing foundations and underground structures. As a rule, suspended particles of a suspension are heterogeneous and differ in shape and size. A model of filtration of a multiparticle suspension in a porous medium is considered. During filtration, the sedimentation rates of particles depend on their sizes and are proportional to the corresponding filtration coefficients, which are a priori unknown. In laboratory experiments, it is possible to determine the total concentration of suspended particles of a suspension at the porous sample inlet and outlet. The filtration coefficients are expressed from measured suspended concentrations. The article proposes a method for solving the inverse problem based on an explicit exact solution of the direct filtration problem at the concentration front. The inverse problem is reduced to a system of nonlinear algebraic equations. For a bidisperse suspension, an exact solution is found; for a multiparticle suspension, the inverse problem is solved numerically. The conditions necessary for the solution existence are derived.
3D Model of Exoskeleton Lower Limbs with Four Variable-Length Links of Adjustable Stiffness for Builder and Rescue Works
Authors: Mukharlyamov Robert , Kaspirovich Ivan , Borisov Andrey , Borisova Veronika
Published: December 2024

A new lower limbs exoskeleton model for builder and rescue workers, firefighters, and personnel of other emergency services is proposed in the paper. The proposed exoskeleton model is more comfortable than the existing ones because it uses links of alterable length and artificial resilience resulting from the magneto-rheological fluid utilization in the link design. The utilization of this fluid makes it possible to control link stiffness by applying external magnetic field. The exoskeleton has four links of controlled length and the same design. Each link includes the absolutely rigid bottom part with a cylinder attached to it and filled with magneto-rheological fluid. A coil of wire is wound on the cylinder surface. The coil is energized by the electric current when required. The top part of the link includes a piston inside the cylinder with a stem passing outside it. The piston moves inside the cylinder filled with magneto-rheological fluid. The piston features microscopic channels through which the magneto-rheological fluid can flow relatively easy in the absence of magnetic field. If magnetic field is applied, the particles of magneto-rheological fluid are arranged in a way to prevent free flow of the fluid through the piston. Thereby the link stiffness, and consequently the link length control are implemented. The paper lists results of numerically found lengthwise forces applied to the piston in the cylinder filled with magneto-rheological fluid. The proposed exoskeleton model can be widely used by builder and rescue workers because of its comfort, high-speed performance, noiselessness, and great developed force.
Numerical Simulation of “Soil-Structure” Dynamic Non-Heterogeneous Systems with Dissipation Effect
Authors: Abirov Rustam , Miralimov Mirzakhid
Published: December 2024

This research attempts to solve the problem of interaction between soil and structure at external dynamic impact. Here was included the properties of soil to absorb seismic waves. It is more comprehensive method and here was taken into account a viscous property of “soil-structure” interaction. This path is more advanced than the methods used in simplified ones. Statement of the problem can be applied in direct or variational form. In this issue, a system of integro-differential equations is compiled based on Ostrogradsky-Hamilton variational principles. For solving the problem, a numerical discrete model by using finite element method for hereditarily deformable systems was proposed. A method has been developed for calculating a viscoelastic infinite half-plane with taking into account a viscous fictive boundary for absorbing elastic waves. So technique by introducing fictive boundary is give us opportunity for obtaining more reliable solution for stress and strain state of structure. However, it should be noted that the rheological properties of the soil as the constitutive relations were not used in this article. The method is implemented by performing specific numerical calculations
Key Points of Cast-in-Place Small Box Girder Concrete Construction of Baishui Lake Bridge
Authors: Wang Ya , Zhou Leiyan , Xia Linwu , Chang Peng
Published: December 2024

Due to the restriction of site and cost, no prefabricated beam yard has been built in this project, but cast-in-place. The construction of cast-in-place box girder requires on-site construction and waiting for the solidification of concrete, which takes a relatively long time and cannot be carried out quickly. The construction site conditions of cast-in-place box girder and the ability of construction personnel are different, which are prone to quality problems and cause potential safety risks. Therefore, when pouring small box girder concrete on the support, preparations should be made, including the control of raw material, concrete mix ratio design, formwork reinforcement, and technical disclosure before construction; secondly, the control of the pouring process, pouring method, pouring sequence, and concrete maintenance and mold removal, so as to ensure the quality of box girder concrete after pouring meets the requirements.
Risk Assessment of Ultra-High Voltage Transmission Line Tower Slope Based on SVM
Authors: Zheng Wulue , Zhang Fuchun , Zhao Yanhui , Song Chunpeng , Zheng Yangliang , Chen Jianghong
Published: December 2024

The aim of this paper is to select 8 types of factors as evaluation indexes through statistical learning theory and support vector machine intelligent algorithm, combined with Matlab computing platform, for the geological environment and conditions and landslide development characteristics of Qingyuan City, Guangdong Province, which is the route of the West-to-East Electricity Transmission Project, and to adopt the support vector machine model under the Linear Kernel Function (LN), the Polynomial Kernel Function (PL), and the Radial Basis Kernel Function (RBF), respectively, to Evaluation of geological disaster risk in the study area. The three trained evaluation models were used to predict the regional hazard evaluation index for the whole study area, and the whole study area was divided into four hazard zones according to the hazard evaluation index, which were low hazard zone, medium hazard zone, high hazard zone, and very high hazard zone, respectively. By comparing the support vector machine models with different kernel functions, we found that the PL-SVM model has the highest prediction accuracy, which indicates that the support vector machine model with polynomial kernel function is more suitable for the slope hazard risk evaluation in this study area. The conclusion of the study can provide a reference for the selection of support vector machine models with different kernel functions to carry out the regional geohazard hazard assessment under similar geological environment conditions.
Research on the Application of Resilient Symbiotic Architectural Design Concept—Illustrated by the Architectural Design of Fengxian Punan Canal Floating Ceramic Cabin
Authors: Lu Nan , Xu Jie
Published: December 2024

With the increasing prominence of global environmental issues and the accelerating process of urbanization, the symbiotic theory has been widely applied in the fields of architectural design and urban planning. In the field of urban planning and architectural design, the research on the concept of symbiosis is constantly developing, but most of the research focuses on the macro direction of urban planning, and there are few relevant studies on the micro level of architectural design. Based on this theory, this paper proposes the architectural design concept of “resilient symbiosis” by optimization and improvement. Taking the architectural scheme design of Fengxian Punan canal floating ceramic cabin as an example, This paper analyzes the application of the concept of resilient symbiosis architecture design from four aspects: shape conception and evolution, modular construction , green building performance, and local materials using. At the same time, it summarizes the concept of resilient symbiosis architecture design, which provides a theoretical and practical exploration for the realization of harmonious coexistence between architecture and environment.
BIM Technology Based on Hospital Project Integrated Pipeline Application Technology
Authors: Yang Kai , Chen Cong , Zhou Zewu , Li Quan , Lv Meng
Published: December 2024

Taking the professional comprehensive application of BIM technology in Jingbei District of Jingzhou Central Hospital as an example, the paper focuses on joint review of drawings, visual disclosure, change management, three-dimensional site layout, deepening design, collision inspection, comprehensive pipeline inspection and so on. In combination with BIM management platform, BIM technology is applied in all stages of project design, optimization and construction, and the actual construction is guided according to BIM optimization analysis, which meets the requirements of traditional Chinese medicine hospital project in terms of progress, quality, safety, cost and other aspects, and also provides a reference for the application of BIM technology to the optimization of hospital construction. BIM technology can effectively manage all the information in the building construction process, reduce the difficulty factor in building construction, better manage the construction of construction projects, and shorten the construction period. The application of BIM technology in project construction management is conducive to the overall development of the construction industry and provides a favorable basis for future construction management.
Advanced Technologies for Utilizing Carbonate-Containing Deposits from Heat Exchange Equipment in Sulfur Composite Materials
Authors: Yusupova A.A. , Medvedeva G.A. , Fakhrutdinova A.I. , Aseeva Z.B. , Baraeva L.R.
Published: December 2024

The relevance of this scientific article stems from the innovative and environmentally sustainable approach of incorporating carbonate-containing deposits from heat exchange equipment (CCDHE) into sulfur composite materials for construction. The study of the properties of such concrete and their potential application in the construction industry is of great practical significance, as it can contribute to improving the quality of building structures, reducing costs, and minimizing harmful environmental impacts. Optimal formulations of sulfur composite material (SCM) have been identified. The physical and mechanical properties of SCMs made from thermal energy waste have been studied, and recommendations for its application have been developed. High physical, mechanical and operational properties of the obtained materials have been established. A technology for producing sulfur composite material based on carbonate-containing deposits from heat exchange equipment (CCDHE) has been developed. The proposed technology aims to comply with the principles of «green chemistry» on the one hand and, on the other, to obtain competitive materials for construction purposes.
Inherent Variability Analysis Based on Rebound Hardness Testing of Concrete
Authors: Kumavat Hemraj R
Published: December 2024

Concrete, a heterogeneous material by nature, exhibits variability in its properties due to differences in raw materials, mixing processes, curing conditions, and environmental exposure. Study focuses on analyzing the inherent variability in concrete properties using rebound hardness testing. The rebound index dataset from laboratory is analyzed by statistical method is crucial important role in engineering application for identification of reliable assessment and variability. From 140 cube specimens with different influencing factors. Eighteen (150–200) cube set specimens are analyzed separately for inherent variability analysis. Correlationship between inherent variability (location, variance and dispersion parameters) measures were studied from dataset of independent cube test specimen. It was realized that, positively skewed distributions seem to be an appropriate fit with a good curve for a larger dataset of frequency histograms of local statistical parameters. The W-stat test for normality parameters is highly acceptable at a very low significance level when applied to the 18 individual cube specimens analyzed separately for the independent cube specimens of rebound results. This study contributes to the understanding of concrete’s inherent variability and provides recommendations for improving the reliability of NDT methods.
Investigation and Prediction of Pullout Behavior of Twisted Fibers from Ultra High Strength Concrete
Authors: Tran Quoc Khanh , Tran Ngoc Thanh
Published: December 2024

This research demonstrates the pullout response of twisted steel fibers from various matrices. The high strength twisted steel fibers, characterized by three twists along their length and a high aspect ratio of 100, were embedded in two types of matrix: high strength concrete (HSC) matrix with a compressive strength of 81 MPa and ultra high strength concrete (UHSC) matrix with a compressive strength of 152 MPa. Moreover, a theoretical model was established to estimate the pullout response of twisted fibers. The experiment results revealed that twisted fibers embedded in the HSC matrix exhibited slip-hardening behavior by maintaining pullout mode during the fiber pullout from matrix, whereas those in the UHSC matrix exhibited brittle failure due to fiber rupture. The HSC matrix produced a 41% lower maximum pullout load but a 1217% higher pullout energy than the UHSC matrix. The theoretical model was able to accurately capture the pullout behavior of twisted fibers from different matrices.
Analysis of Rheological Properties of Two Types of Asphalt After Aging
Authors: Zhou Yong , Ren Haiqing , Bi Fei , Zhou Shengjie , Fan Liang
Published: December 2024

This study aims to elucidate the differences in aging characteristics between base asphalt and modified asphalt by simulating both short-term and long-term aging processes. The aging of asphalt is simulated using two established methods: the Thin Film Oven Test (TFOT) to replicate short-term aging and the Pressure Aging Vessel (PAV) to simulate long-term aging. Rheological properties of both the original and aged asphalt samples are evaluated using a Dynamic Shear Rheometer (DSR), providing comprehensive data on the material’s behavior across varying aging stages. The analysis focuses on critical factors such as low-temperature glass transition, modulus, and viscoelastic properties. These parameters are essential in understanding the aging mechanisms and their impact on the performance of asphalt in real-world engineering applications. The findings are expected to offer valuable insights into the durability and longevity of asphalt pavements, particularly in how modified asphalts might offer enhanced resistance to aging compared to their unmodified counterparts.
Study on the Preparation and Rheological Properties of CR/SBS Composite Modified Asphalt
Authors: Ren Haiqing , Li Yongjin , Zhang Chuanxu , Yu Peihan , Zhao Xin , Bi Fei
Published: December 2024

This study investigates the effects of varying styrene-butadiene-styrene (SBS) content, crumb rubber (CR) powder content, and oil-rubber ratio on the modification of asphalt in the preparation of composite modified asphalt. To optimize the experimental design, an orthogonal testing approach was employed. The softening point served as the primary evaluation index, while 5°C ductility, penetration, and elastic recovery were utilized as secondary indices to identify the optimal content of modifiers. Fluorescence microscopy was used to observe the fluorescence spectra of the asphalt samples, providing insights into the distribution and interaction of the modifiers within the asphalt matrix. Additionally, rheological properties were analyzed using Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR) tests. These instruments facilitated a comparative analysis between the composite modified asphalt and base asphalt, SBS-modified asphalt, and CR rubber powder asphalt, with a particular focus on their high and low-temperature performance characteristics. This comprehensive evaluation aims to enhance the understanding of composite asphalt modification and its potential for improved performance in various environmental conditions.
Research on the Mechanical Properties of Polypropylene Fiber Cement-Based Composites
Authors: Liu Yun , Lai Jie , Liu Yuan
Published: December 2024

In order to address the issue of cracking in traditional reinforced concrete beams, which leads to a reduced service life of buildings. This paper investigated the mechanical properties of polypropylene fiber cement-based composites to enhance the micro tensile performance of beams. The experiments demonstrated that when a single type of fiber was incorporated, polypropylene has an adverse effect on the performance of the cement-based composites in the early stages, resulting in reduced strength of the matrix. When mixed fibers were used, the optimal polypropylene content was found to be 0.15%. The load-displacement behavior of the specimens exhibits four distinct stages: compaction, elastic, plastic, and failure stages. The elastic stage shown a relatively large range, while the plastic stage was not pronounced, necessitating further analysis through specific experimental data. The experimental revealed that for polypropylene fiber-reinforced cement-based composites, the early strength is relatively low and can even have a negative effect on the substrate.
Predicting the Increase in Concrete Strength Range at Different Temperatures
Authors: Dmitrienko Vladimir , Maslenikov Stanislav , Kokunko Irina , Dmitrienko Nadezhda
Published: December 2024

Complex design solutions, increased loads, cheaper materials and a number of other factors determine high requirements for the reliability and durability of objects. The preservation of substantial quantities of mono-lithic and reinforced concrete necessitates a heightened focus on the assurance of their requisite characteristics during the erection of load-bearing structures, irrespective of the prevailing construction conditions. The reduction of construction terms and, consequently, the early loading of structures under conditions of changing concrete properties, influenced by a variety of factors, contribute to the development of destructive processes and, in some cases, the destruction of building frame elements. The objective of the presented study is to investigate the time-varying mechanical characteristics of concrete and to predict the strength gain with decreasing temperature. To address this issue, a bespoke methodology has been devised for laboratory studies of sample preparation, storage and compression testing. The results of testing samples of heavy concrete hardening at temperatures in the range from +1°C to +20°C were subjected to statistical processing, and a multiple regression equation was obtained. This equation enables the strength gain of compositions at different hardening times to be evaluated. A comparison of the results of numerous surveys of various structures at construction sites in the region with the results of calculating the predicted strength of concrete revealed a satisfactory convergence of laboratory and production tests. The proposed multiple regression equation for calculating the predicted strength of concrete depending on temperature and curing time will facilitate the determination of the potential loading period for structures, thereby enhancing the efficiency of labour organization at the construction site.
Finite Element Study on Mechanical Properties of Laminated Plates Under Reciprocating Loads
Authors: Zhao Yongqiang , Zheng Zhiyuan , Song Yafen , Chen Huanxin , Xie Jingjing
Published: December 2024

In order to study the mechanical properties of superimposed surfaces under reciprocating loads, a nonlinear finite element model of simply supported superimposed plates under different superimposed surface roughness conditions was established. The hysteretic curve, skeleton curve, stiffness degradation, energy dissipation coefficient, ductility coefficient and other characteristics of the comparison plates were investigated. The effects of surface roughness, thickness ratio of prefabricated layer to cast layer, reinforcement ratio of truss reinforcement, shear reinforcement form and other parameters on the mechanical performance of the composite plate are studied. The results show that the hysteretic curve of the composite plate with truss reinforcement has a certain “pinch” phenomenon compared with the hysteretic curve of the cast plate. The stiffness and energy dissipation of the composite plate are increased after the lamination treatment, and the displacement ductility of the composite plate is lower than that of the cast plate. Different thickness ratios of prefabricated/post-cast plates have significant effects on load-bearing properties and energy-consuming capacity of components. The larger the ratio of truss reinforcement, the stronger the bearing capacity and energy dissipation performance of the composite plate, but the worse the ductility.
Comparison of Geosynthetic Materials
Authors: Iskakov B.A. , Iskakova G.Z. , Kabdrasyl Zh. , Khalykov Sh. , Yessenova K.A. , Yung M.
Published: December 2024

Geosynthetic materials have become indispensable in modern construction and engineering, owing to their distinctive properties and wide-ranging applications. This paper offers a comprehensive comparative analysis of four primary types of geosynthetic materials: geotextiles, geomembranes, geogrids, and geocells. The study delves into their physical-mechanical properties, various areas of application, as well as their respective advantages and limitations. By drawing on data from existing research, the analysis examines key factors such as tensile strength, filtration and waterproofing capabilities, resistance to chemical exposure, and overall cost-effectiveness. The findings underscore that each type of geosynthetic material possesses unique characteristics that significantly influence its performance in different engineering contexts. For instance, geotextiles are highly effective in soil filtration and stabilization, making them ideal for groundwork and foundation reinforcement. Geomembranes, on the other hand, offer exceptional waterproofing solutions, ensuring long-term protection against moisture and environmental degradation. Geogrids are particularly useful for enhancing the load-bearing capacity and durability of pavements, while geocells are instrumental in fortifying slopes and controlling erosion. In conclusion, the paper highlights the critical importance of carefully selecting and applying the appropriate geosynthetic materials to achieve optimal construction outcomes and ensure the longevity and reliability of engineering projects.
Investigation of Mechanical Behavior of Steel Fiber-Reinforced Geopolymer Concrete Under Multi-Axial Stress Conditions
Authors: Ranit A.B. , Futane N.S. , Dhawale V.R. , Dhawade S.M. , Ingalkar R.S. , Harle S.M.
Published: December 2024

This study investigates the influence of steel fibers on the mechanical properties of concrete, particularly focusing on compressive strength, critical stress, and ductility. The inclusion of steel fibers, with lengths of 6 mm, 10 mm, and 15 mm and aspect ratios of 50, 83, and 125, significantly enhances these properties, with longer fibers and higher aspect ratios proving more effective under increased confining pressures. The stress-strain analysis demonstrates that higher confining pressures lead to greater ductility, allowing the material to sustain larger strains before failure, which is advantageous for geotechnical and structural engineering applications. Although the simulation model closely replicates the material’s behavior, some deviations occur at higher strains, indicating a need for further refinement. Overall, the study highlights the beneficial role of steel fibers, especially at higher volumes and aspect ratios, in improving the mechanical performance of fiber-reinforced concrete under high-stress conditions.
Effects of Plastic Hinge Properties on Nonlinear Static Analysis of Reinforced Concrete Frames
Authors: Le The Anh , Pham Ngoc Hieu
Published: December 2024

The paper presents the influence of plastic hinge properties on the nonlinear static analysis using the pushover method for a four-story reinforced concrete frame. The pushover static analysis is commonly used to assess the behavior of structures under seismic actions by applying gradually increasing lateral loads while keeping the vertical load constant. The lateral load will increase until structural failure occurs, during which plastic hinges will form in the structural components. In the nonlinear analysis of such structures, beams and columns are often simplified as concentrated plastic joints or plastic regions at both ends to save time. Many authors have proposed a variety of formulas to determine plastic hinge lengths. A four-story reinforced concrete frame is designed to resist seismic actions with a medium ductility level (DCM) according to TCVN 9386-2012. This paper will conduct a pushover nonlinear static analysis of this reinforced concrete frame with various plastic hinge models. The analysis results reveal insignificant differences among the various plastic hinge models, followed by the recommendations for designing reinforced concrete frames.
Geopolymer Composite Materials for Low-Carbon Hydraulic Engineering and Infrastructure Construction in the Arctic Regions
Authors: Mamulat Stanislav , Bychkov Alexey , Khaydarov Bekzod
Published: December 2024

Utilizing geopolymer materials from industrial wastes in strengthening road, air-field, and marine infrastructure layers offers multiple benefits. This approach efficiently manages industrial wastes, reduces carbon footprint in material production and transportation, enhances structural reliability, and reduces maintenance needs. This study presents the optimal Blast Furnace Granulated Slag content in a geopolymer composite to achieve the required physical and mechanical properties. A pilot project was conducted to implement the composite in a real engineering project. During the experiment, at a site located on the shoreline of the Severnaya Dvina River in the Arctic zone of the Komi region, Russia, a geopolymer composite mat was prepared and laid to gain strength during a temperature drop from –17 °C to +12 °C. The results showed that replacing 40% of Portland cement with slag contributes to achieving maximum compressive strength both at 28 and 180 days of curing. It was also confirmed that the composite is moderately frost-resistant. The condition of the geopolymer composite mat after 3 years of service in an area with variable humidity levels is satisfactory. Thus, the experimental results confirm that the use of local slag leads to a significant reduction in the carbon footprint by reducing the consumption of Portland cement and the volume of aggregates for transportation. Carbon footprint calculations confirm that the use of local slag leads to a significant reduction in the carbon footprint by reducing the consumption of Portland cement and aggregate materials for the transportation.
Study on the Coupling Relationship Between Hydropower Development and Ecological Environment in Qinghai Province
Authors: Hu Yidong , Shi Shengbin , Yu Shijia
Published: December 2024

Qinghai Province has a unique geographic location and abundant hydropower resources, which inevitably involves constant collision with the ecological environment in the process, and there is an urgent need to clarify the coupling relationship between hydropower development and the ecological environment in Qinghai Province from the theoretical level, in order to realize the coordinated development of the two. This paper selects Qinghai Province as the research object, takes 2011–2020 as the research period, and uses the entropy weight TOPSIS comprehensive evaluation model and the coupling coordination degree model to measure and analyze the comprehensive index of hydropower development, the comprehensive index of the ecological environment, and the coupling coordination degree of hydropower development and the ecological environment in Qinghai Province respectively. The results show that: (1) the coupling degree of hydropower development and ecological environment in Qinghai Province is mostly located around 0.9 in ten years, and the impact of hydropower development on the ecological environment is significant; (2) the coupling degree of coordination between hydropower development and ecological environment in Qinghai Province is generally evolving towards a good trend, and is currently in the stage of barely coordinated.
Simulation Analysis of Longitudinal Deformation of Rock Mass on Both Sides of Power System
Authors: Zhang Xu , Jin Heping , Lin Yifeng , Jiang Juan , Luo Huiheng , Xu Yanli , Zhang Yu , Peng Bo , Zhang Yongzhi
Published: December 2024

Aiming at a large power project in Jinsha River, China, we have discussed the deformation response law of upstream and downstream valleys and reservoirs caused by reservoir impoundment. A three-dimensional numerical simulation model near the dam area is established, and the radial displacement and development law, as well as the distribution characteristics of radial deformation rate are analyzed. Measuring points are arranged near the dam area, and the deformation simulation process is tracked and analyzed. The radial displacement characteristics of different sections, the longitudinal dis-placement distribution of different elevations on the left and right banks of the plunge pool, and the deformation evolution law of measuring points at key positions and different elevations on both banks are analyzed. The re-search results of this paper can provide reference for the design analysis and safety monitoring of similar high dam projects.
The Relationship Between Ground Resistivity and Rainfall Change – A Case Study of the Baochang Seismic Station
Authors: Jia Yanjie , Jia Xinye , Bai Shaoqi , Wen Jinlong , Zhen Qi
Published: December 2024

The resistivity of the Baochang seismic platform is analyzed in relation to rainfall observation data in the region. This analysis takes into account the underground electrical structure of the station and utilizes the influence coefficient theory and the convolution filter method to examine the relationship between resistivity and changes in rainfall. The convolution filter approach successfully demonstrates that the yearly variation pattern of the rainfall data aligns with the real observation data. This finding suggests that rainfall is the primary factor contributing to the annual variation in the resistivity of the Baochang seismic platform. This study provides a concise overview of the factors that produce interference in observation data and presents a quick identification technique specifically designed for changes in the resistivity data of Baochang land. The aim is to provide a valuable reference for daily analysis, seismic consultation, and anomaly research and judgment in the future.
Solving Potential Problems with the Boundary Manifold Method
Authors: Nie Zhibao , Ding Shijun , Kong Sen , Ding Mintao , Liu Kaiyuan
Published: December 2024

The potential problem is always a hot issue in engineering research, and many physical phenomena can be attributed to this problem. To address the potential problem, a new boundary-type numerical solution method, the boundary manifold method, is proposed by combining the boundary element method (BEM) and the numerical manifold method (NMM). Due to the introduction of Galerkin’s formal boundary integral equation and boundary covering system, the proposed method has the advantages of dimension reduction of the BEM and flexible selection of the local basis of the NMM. Based on the proposed method, three two-dimensional potential problems with analytical solutions, that is, a Neumann problem and two Dirichlet problems are analyzed. The results of numerical examples show that: 1) the proposed method can be applied to solve the potential problem and has high calculation accuracy, and 2) due to the same flexibility of local basis selection as NMM, p-adaptive analysis can be easily implemented.
Stability Study of High Slope Areas Near Bridges in Seismic Zones of South American Highlands
Authors: Wang Wei
Published: December 2024

The Andes Mountains of South America has a complex geological condition, which characterized by rugged terrain numerous valleys and volcanoes, frequent seismic activities and deformation and instability failures of mountain slopes within this area [1]. When constructing bridge projects in this region, unstable slopes pose significant risks. This paper focuses on the Guayasamin Bridge in Ecuador, using physical and mechanical soil parameters based on laboratory test data. A comprehensive analysis was conducted by considering rock mass parameters from the Guayasamin Bridge and Guayasamin Tunnel investigation results, rock mass parameters calculated using the Hoek-Brown failure criterion, and slope failure parameters induced by the 2021 earthquake obtained through inversion methods [4]. These analyses were used to calculate the stability of the mountain slopes under different working conditions, providing a basis for slope support engineering. This approach effectively addresses the challenges posed by unstable slopes in high-seismic regions to bridge construction and operation.