bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical study of aerodynamic characteristics and particle motion in square cylinder vortex flow with different void ratios
Authors: Xiong Feng , Yin Kang , Sun Ke
Published: August 2023

In actual production practice, blunt block structures usually exist in multiple forms simultaneously, such as buildings, bridges, and offshore platforms. Flow around multi-cylinder structures is often accompanied by complex phenomena, including separation and reattachment of shear layers, vortex-structure interactions, and the evolution of wake vortex streets. These phenomena can worsen fatigue damage or local accumulation of harmful substances on bluff block structures. The main purpose of this study is to analyze the complex flow phenomena of square cylinders with different void ratios and the distribution of particulate matter in the flow. The results show that the drag forces applied to the square cylinder under different void conditions will be very different, the flow will also vary greatly, and the location of particle deposition will also change significantly with the change of void ratio conditions.
Numerical analysis of the effect of different V-winglets on the aerodynamic performance of wind turbines
Authors: zhang Pengyu , Ma Jianlong
Published: August 2023

The aerodynamic characteristics and flow field distribution of wind turbines with the addition of V-flat winglets and V-winglets are investigated to investigate the effects of power, blade surface pressure, and flow field distribution of wind turbines with different V-winglets at rated operating conditions. The results show that the installation of V-winglets at the blade tip can increase the total power of the wind turbine. The V-winglets have better aerodynamic performance, and the total power is 1.57% higher than that without the winglets at rated operating conditions. The presence of V-winglets increases the pressure difference on the blade tip surface, and the pressure difference on the blade tip surface is more significant for flat V-winglets than for V-winglets. The V-winglets weaken the intensity of the blade tip disturbance, which makes the blade tip vortex V-shaped airfoil reduce the intensity of leaf tip disturbance and makes the vortex nucleus position far away from the leaf tip area. This can reduce the adverse effect of the leaf tip vortex on the main body of the blade.
Numerical Study on the Aerodynamic Characteristics of High Bypass Ratio Engine Exhaust System
Authors: Cai Beijing , Chao Xiao , Liu Kaili , Wang Lei
Published: August 2023

Research using numerical simulation methods on the aerodynamic performance of the high bypass ratio civil engine exhaust system for civil aircraft has been launched in this paper. The influence of flight conditions and aircraft integration on the aerodynamic performance of the exhaust system is systematically analyzed. The result shows that flight Mach number manifests an inhibition influence on the mass flow of the exhaust system and a positive impact on the thrust of the exhaust system. Flight altitude has a negative influence on the mass flow and the thrust of the exhaust system. Aircraft body integration represents a gain on the exhausting flow and an opposite influence on the thrust.
Torque Ripple Suppression Research of V-Shaped External Rotor Permanent Magnet Motor
Authors: Liang Jianwei , Guo Peiyao , Wang Xinhua , Yin Liying
Published: August 2023

Aiming at the problems of large torque ripple and poor output torque performance of external rotor permanent magnet synchronous motors, this paper took a three-phase 24-slot 19-pole external rotor motor as the research object, uses the magnetic circuit method and Lorentz theorem to analyze and calculate the motor torque, and improved the output torque by optimizing the position parameters of the V-shaped permanent magnet. The output torque was further optimized by a circular groove on the side of the stator teeth. The finite element simulation results show that the output performance of the motor can be improved by selecting the proper permanent magnet position. Stator tooth chooses slot position for Z = 1.2 mm, R = 3.5 mm torque ripple when dropped by 81.9%, up 7.6% on the output torque, motor performance is improved.
Hydraulic Systems Fault Diagnosis Based on Random Forests Recursive Feature Elimination and XGBoost
Authors: Song Zixiong , Wang Junle , Wang Mingxian , Yang Bingjian , Cui Langfu , Zhang Qingzhen , Xiang Gang , Lin Ruishi
Published: August 2023

This paper proposes an RFRFE-XGBoost method for fault mode recognition in hydraulic systems. The proposed method combines random forests-based recursive feature elimination (RFRFE) and extreme gradient boosting (XGBoost) to effectively identify important features and improve fault diagnosis efficiency and accuracy. The method is validated on relevant datasets and compared with existing methods, demonstrating its effectiveness and superiority. The results show that RFRFE-XGBoost can accurately recognize various fault modes and outperforms other methods in terms of classification accuracy and computational efficiency. The proposed method provides a promising approach for fault diagnosis in complex systems.
Adaptive Super-Twisting Sliding Mode Forward Tracking Guidance Law Considering Missile Body Characteristics
Authors: Liu Xiang , Ding Xutuo , Wang Yunlong , Li Yahui , Wang Yukai
Published: August 2023

Aiming at the problem of forward tracking guidance munitions with missile body characteristics intercepting maneuvering targets, and to improve the hit accuracy of forward tracking guidance system, this paper proposes an adaptive super-twisting sliding mode forward tracking guidance algorithm considering the impact of first-order overload characteristics of missile body and input saturation limitation. Firstly, the nonlinear model of the guidance system is made by the kinematic relation for projectile-target, the principle for the forward tracking interception, the overload characteristic of the missile body, and the input saturation limitation. Secondly, a finite time interference observer (FTIO) is adopted to accurately estimate the nonlinear interference in the guidance system, furthermore, an adaptive super-twisting algorithm for slide mode control is used to design the forward tracking guidance algorithm considering the characteristics of the projectile body. Finally, the results by simulation indicate the adaptive super-twisting slide mode for forward tracking guidance algorithm considering characteristics of the projectile body designed in this paper has better-hit accuracy.
Numerical study of the momentum and heat transfer between an oblate ellipsoid and a gas in uniform flow
Authors: Xiong Ting , Chen Chenchen , Chen Yong , Fang Zhenlong
Published: August 2023

In this study, drag coefficient (cd
) and Nusselt number (Nu) for oblate ellipsoids with different incident angles (θ) and particle aspect ratios (Ar) in uniform flow have been computed over a wide range of Re ∈[10,500]. Finally, a new drag coefficient correlation is proposed, which covers a wider range of oblate ellipsoids. Surprisingly, we observe that the incident angle has a negligible effect on the Nusselt number for the oblate ellipsoids in the Reynolds number range studied. The Nusselt number for oblate ellipsoids with incident angle (θ) can be approximated accurately by the averaged Nusselt number for different incident angles. Thus, a new Nusselt number correlation for oblate ellipsoids for Re ∈[10,500] and Ar ∈[0.1,0.8] is proposed. The new correlations developed are expected to improve the accuracy of Euler-Lagrange simulations of gas-solid heat transfer comprising oblate ellipsoids.
Aircraft Accessibility Based on Generalized Regression Neural Network
Authors: Fan Zhonghang , Zhang Xuhui , Lu Ying , Hu Yuchuan , Liu Xuanlin
Published: August 2023

According to the requirements of aircraft accessibility judgment, based on the existing research, this paper proposes two accessibility judgment methods based on the “initial position velocity threshold range” and “expected landing site velocity threshold range”. Firstly, the motion model of the aircraft is established, and the accessibility judgment sample library is established by using the trajectory planning method. Then, the initial and landing velocities are selected as the prediction targets, and the neural network is established to achieve accessibility prediction and judgment. Finally, the simulation analysis of the unpowered aircraft diving stage scene is carried out. The results show that the accessibility judgment model designed in this paper has high prediction accuracy and preliminary accessibility judgment ability. This paper realizes the optimization of the existing scheme and provides a method for the research field of accessibility judgment.
Optimization of Aerodynamic Profile of Ground Vehicle
Authors: Gan Yifan , Li Linghao
Published: August 2023

In this paper, the aerodynamic profiles of different types of ground vehicles, racing cars, freight cars, and bullet trains, as well as their shape design and use, will be introduced and discussed by using the equation

F
d

=

C
d

⋅

1
2

ρ

V
2

A

. The methods adopted by predecessors o find the best aerodynamic profile for these vehicles are also introduced. The conclusion is that the best aerodynamic profile for race cars is equipped with spoilers and a relatively great slicing angle at the rear bottom of the vehicle. Furthermore, diffusers are optional but can also decrease the drag force. For lorries, the best modification is completely sealing the gap between the trailer and undercarriage with a dynamic rear flap. If possible, add roof tapering on the trailer, but it will reduce the amount of cargo shipped. For a bullet train, the longer the nose of the train is, the less drag it will experience.
Equalization control of rudder force fight under hydraulic servo-actuation system
Authors: Qu Liang , Li Nan , Ye Ji Hai , Xu You Ping
Published: August 2023

The main steering rudder surface of civil aircraft usually adopts the design of redundant degree actuator channels to meet the requirements of high safety of flight control systems. However, the use of the main-main actuator operating leads to a force fight phenomenon, which can bring fatigue and other effects on the rudder surface structure and even threaten flight safety. In this paper, the rudder operating system with three residual degrees of main-main-main operation is taken as the object. A proportional-integral equalization algorithm based on the dual compensation of actuator pressure difference and position is investigated to mitigate the force fight phenomenon. The effectiveness of this force fight equalization method is verified by Simulink simulation and the iron bird experiment.
A Method for Generating Error-caused Scenarios
Authors: Du Junchao , Zhu Chongyuan , Bao Yang , Hu Qianchao , Liu Binglin , Liu Haitian , Wang Feng
Published: August 2023

In recent years, with the development of artificial intelligence, Unmanned Autonomous Systems (UAS) have also developed rapidly. It is necessary to conduct sufficient testing and evaluation of UAS before using it. This paper proposes a method for generating error-caused scenarios that lead to incorrect behavior in UAS, and how to evaluate the level of incorrect behavior in UAS caused by the scenario. Based on the method proposed in this paper, error-caused scenarios can be generated in the simulation platform, and the dataset constructed from these scenarios can be input into the target detection model to verify the effectiveness of error-caused scenarios. Our experiments have shown that the scenarios generated by the method can easily lead to errors in UAS, and the method can play an important role in the field of model-based UAS testing and validation.
Graph Transformation Based on Heterogeneous Information Network for Graph Algorithms
Authors: Liu Zhenguo , Ma Chao , Zhao Jimiao , Hu Haiyang , Yin Xiongyi
Published: August 2023

In the finical risk control, the graph structure data increasingly show its unique charm, especially the heterogeneous information network (HIN). And, graph computing algorithms for the data mining based on network is the most popular way at the moment. But, most of them require the graph network must have homogeneity and could not be applied to heterogeneous networks. Although the neural network models have some work in the HIN, which like heterogeneous graph neural networks, but these ways cannot provide enough interpretability due to its operations in black-box. In this paper, we summarize strategies to transform the HIN into homogeneous network. And we propose methods aim to rebuild HIN as several homogeneous networks at fine-grained level and greatly retain the original network topological structure information compared the previous which easy to lose sight of. The effectiveness of our method is verified by real data and community detection algorithms. In the experiment, the analysis found that our approached consistently perform promising results compared with the coarse-grained data processing on HIN.
FG-PFC: A Fine-Grained PFC Mechanism for Lossless RDMA
Authors: Li Shibao , Wang Chengzhi , Zhang Yunwu , Ma Chenxu , Li Longfei , Cui Xuerong , Liu Jianhang
Published: August 2023

Remote Direct Memory Access (RDMA) is widely deployed in data centers to improve the performance, efficiency, and reliability of data centers. Priority-based Flow Control (PFC) can ensure no packet loss as a necessary approach to achieve lossless RDMA. However, since PFC is a coarse-grained flow control mechanism based on port and priority, it can cause the head-of-line blocking problem and affect other flows, resulting in high latency. In this paper, we propose a fine-grained PFC mechanism (FG-PFC), which refines port and priority into flow granularity and further determines and pauses the flow most likely to cause congestion. The benefit is reducing the persistent high occupancy of the buffer and protecting the innocent flow. Simulations and experiments demonstrate that FG-PFC outperforms PFC in terms of flow completion time (FCT).
System Health Assessment Model Based on Anomaly Detection
Authors: Yu Hai , Cheng Xinyuan , Liu Juan , Cai Zhengong , Lv Fengmin
Published: August 2023

Accurately assessing system health and taking timely interventions play a crucial role in promoting intelligent system operation. Traditional system health assessment techniques depend on human-set thresholds, which are only appropriate for tracking a few indicators and do not accurately represent the system’s health overall. Therefore, keeping track of a large amount of data and a diverse variety of indicators will be extremely challenging. To address this issue, we develop the AD_Select anomaly detection algorithm and suggest a system health assessment model based on indicator anomaly detection. By fusing anomaly detection with system health assessment, this algorithm increases the scientific rigor and precision of health assessment. The experiments of AD_Select anomaly detection algorithm and healthiness assessment model are conducted on the 2018AIOps dataset and industrial dataset respectively, and the results show that both the AD_Select algorithm and the healthiness assessment model proposed in this paper achieve good performance.
Fan Rotation Speed Real-Time Optimizations of Continuous Annealing Line with Mechanism-Guided Multitask Classification and Regression Model
Authors: Chen Kai , Huang Feng , Zhang Heming
Published: August 2023

Fast cooling with gas jets in the rapid cooling section plays significant role in the process of steel strip galvanization. The large number of the cooling fans to generate the gas jets and the frequent change of the strip dimension, the strip velocity and the inlet strip temperature contribute to the great complexity of the fan rotation speed regulations. The experience-dominated regulation method does not work well in real production. This paper proposes a multitask classification and regression (MTCR) model to optimize the fan rotation speed in real time. A heat transfer model is firstly built in the form of partial differential equations (PDEs) and is used to construct the features of the MTCR model. The overall heat transfer coefficient is calculated and analysed. More than 575, 000 data records from the real production line are used to construct the features, and train and evaluate the MTCR model. In addition, the predictions of the MTCR model are compared with that of the multitask regression (MTR) model and the single task regression (STR) model. All the models perform well for the rotation speed predictions of the switched-on fans, while the MTCR model performs better in the whole test dataset.
Design and verification of DFE re-decision algorithm for PAM6 high-speed transceiver based on FPGA
Authors: Zou Dongwei , Song Kezhu , Zhu Chengyang , Chen Zhuo , Zhong Xiangshi , Wu Tong
Published: August 2023

In this paper, a decision feedback equalizer (DFE) re-decision algorithm for a 6-level pulse-amplitude-modulation (PAM6) high-speed transceiver is proposed. PAM6 is a two-dimensional (2D) modulation. The four outer points are not used in the 2D constellation diagram to reduce the output power. Although the four outer points will not be modulated, they may be encountered during demodulation. This paper considers the above situation and theoretically analyzes the DFE module under the additive white Gaussian noise (AWGN) channel. Compared with the traditional pipelined DFE structure, the proposed algorithm can help solve the four outer points in PAM6. A serializer/deserializer (SerDes) simulation system is built based on a field programmable gate array (FPGA), and the performance of the proposed algorithm is carried out on the simulation system. According to this proposed algorithm, the symbol error rate (SER) of the PAM6 SerDes system can be reduced, and the system performance can be improved. When the DFE tap coefficient is 0.50 and the signal-to-noise ratio (SNR) is 22.0 dB, the proposed algorithm can additionally correct 8.18 % of erroneous symbols. When the DFE tap coefficient is 1.00 and the SNR is 22.0 dB, the proposed algorithm can additionally correct 17.30 % of erroneous symbols.
Preface II International scientific and practical conference “Ensuring sustainable development: agriculture, ecology, energy and Earth science”
Authors: Gibadullin Arthur , Sadriddinov Manuchehr , Morkovkin Dmitry
Published: August 2023

Within the framework of the presented material, the results of the conducted II International scientific and practical conference “Ensuring sustainable development: agriculture, ecology, energy and Earth science”.
Representativeness errors in the assessment of pollution discharge in wastewater
Authors: Rosental O M , Sambursky G A
Published: August 2023

The issues of determining the quality of wastewater are relevant for various countries within the framework of environmental regulation. The methods used for calculating the quality standards of wastewater discharged into reservoirs have different degrees of justification and, thus, can cause systemic errors in the analysis of the quality of treated wastewater. Another reason for possible inconsistencies is errors in the unrepresentativeness of analytical studies and sampling procedures. Based on the fact that average values, including annual averages, are used to determine the acceptable quality of wastewater treatment, this article shows options for negative impacts on water bodies from various objects, taking into account the real contribution to the volume of such negative impacts.
Prospects for the use of solar energy
Authors: Ovchinnikova S V , Schneider E M , Borovkov A V , Lyamina A A , Yu Dvornokova O
Published: August 2023

Nowadays, all over the world, including in Russia, there is an acute question of the development and implementation of new energy sources, and more and more people are using them. In the presented work, the question of the feasibility of using solar panels was studied, and an economic justification was given.
Phytosanitary indicators of fodder crops under using organic cultivation technology
Authors: Trufanov A M , Voronin A N , Shchukin S V , Romanina Ya S , Tikhonov A V
Published: August 2023

The article provides data based on a four-year study of five cultivation technologies of different intensity, including organic. On the example of seven crops of fodder crop rotation, the effectiveness of controlling phytosanitary indicators - the number and mass of weeds, the spread of diseases and the number of insect pests, which are an obstacle to the widespread use of ecological cultivation technologies, was studied. The results of the research made it possible to recommend perennial grasses up to 3 years of use for inclusion in fodder crop rotations in order to improve the phytosanitary condition of crops, and corn in order to obtain high fodder crop rotation productivity. For the cultivation of forage crops, the use of organic technology is fully justified, as it contributed to the reduction in the abundance of weeds, minimized the prevalence of diseases of annual and perennial grasses, corn, reduced the number of pests; provided increase in productivity compared to extensive technology.
Soil pollution by heavy metals
Authors: Grafkina M V , Pitryuk A V , Goryacheva E V
Published: August 2023

An increase in the content of heavy metals in soils is an environmental threat to agriculture, as it is associated with the accumulation of toxicants in plants, which negatively affects the quality of crop production and poses a danger to human health. Each region has its own specifics, expressed by the types of pollution and trends in their changes. The article presents data on the analysis and evaluation of the categories of Primorsky Krai lands for their intended purpose, the problem of soil pollution with heavy metals is considered. On the basis of open data, the levels of soil pollution by territorial formations were determined, the main sources of heavy metal pollution were identified, unsatisfactory soil samples that did not meet hygienic standards for the content of heavy metals for ten years were analyzed, and the trend of their change was revealed. The main types of pollution, the boundaries of the spread of pollution and the differences in the presence of heavy metals such as lead, copper, nickel, zinc and manganese in the soils of territorial formations of the region are revealed. Recommendations are formulated to reduce the technogenic negative impact of industry, which will reduce the content of heavy metals in soils. Proposals have also been made to improve the monitoring system for the content of heavy metals in the soil to obtain more complete information.
Co-vocalisation of Eagle Owl and other owls in the natural and climatic conditions of the Middle Volga region
Authors: Andreychev A V , Kuznetsov V A , Alpeev M A , Lapshin A S
Published: August 2023

The article considers the co-vocalisation of Eagle Owl and other species of owls. The studies were carried out using digital voice recorders in the habitats of the eagle owl. The natural and climatic conditions of the area in which co-vocalisation was noted were analyzed. Rare cases of co-vocalisation of Eagle Owl and its prey, primarily the Ural Owl and the Long-eared Owl, have been identified. Co-vocalisation was revealed only in winter and spring. This is due to the breeding season of birds. The presented study reflects the environmental sustainability of a particular area.
Selective oil saturation of Verkhnechimidikeenskoe oil manifestation
Authors: Vasilev R I , Sivtsev A I , Menkyarova V S
Published: August 2023

The article considers the problem of possible oil-bearing of the section’s upper part in the area of permafrost’s distribution on the example of the north-east of the Siberian platform. The actual data testifying to the existence of permeable intervals in the permafrost rocks (PFR) are presented. The main attention is paid to the unusual «hanging» distribution of oil inside the sand formation. This low-thickness lower Jurassic formation contains a concentration of oil of a lensoid shape. At the same time unaltered areas of the sand formation (without saturation) surrounding top and bottom saturated part do not differ in lithological characteristics. The assumption about the relevance of the Verkhnechimidikeenskoe Oil Manifestation to the relic inter-permafrost aquifer is made. As a modern analogue, the sufficiently detailed distribution zone of inter-permafrost aquifers on the northern slope of the Aldanskaya anteclise with similar lithological-stratigraphic performance is briefly described.
Formation of a recreational component in the natural and ecological framework of an industrial area in order to ensure its sustainable development
Authors: Podkovyrova M A , Kucherov D I , Volobueva O N
Published: August 2023

In the article, the necessity to improve the system of natural and ecological framework of Nefteyugansky district, Russia, is substantiated. It is caused, on the one hand, by the increased degradation of natural (land) resources under anthropogenic and technogenic impact of oil and gas complex, and, on the other hand, by the real need to develop tourist and recreational infrastructure in the economy and nature management of the district. The purpose of the study is to analyze the state of the land and property complex of the district, including an assessment of its natural resource, tourist, recreational, and socio-economic potential. Using domestic and foreign experiences, the authors propose a number of techniques that allow investigating the supporting frameworks as the basis for formation and development of a municipal district; determining the actual state of the natural and ecological framework; studying trends in the development of the economy, and the possibilities of expanding the socio-economic sphere regarding tourist and recreational activities, which, in turn, will allow optimizing the existing system of natural and ecological framework in the near future. A comprehensive landscape and ecological approach to improving the natural and ecological framework of the municipal district based on the formation of a tourist and recreational component in its structure, as well as optimization of natural and economic systems, will ensure the most sustainable development of the studied territory.
Landscape structure of the territory of the district Pustynsky of the projected National Park Nizhegorodskoe Zavolzh’e
Authors: Astashin A E , Vatina O E , Fomina A I , Badin M M , Astashina N I
Published: August 2023

The paper presents the results of landscape differentiation of the territory of the district Pustynsky of the projected National Park Nizhegorodskoe Zavolzh’e, performed at the hierarchical level of landscape types. The researched territory is located in the broad-leaved forest subzone of the forest-steppe zone, indigenous vegetation has been preserved on its territory - broad-leaved spruce, pine, pine-spruce forests. Currently, is being completed work on the creation of the Nizhny Novgorod Region’s first national park Nizhegorodskoe Zavolzh’e, which is designed as a cluster, including five sites. The specifics of the national park’s operating mode require functional zoning of the territory, taking into account the vulnerability of natural complexes, permissible recreational loads and distribution areas of rare plant and animal species, which determines the high demand for landscape zoning schemes necessary for the effective organization of environmental and recreational activities. The article presents a scheme of landscape zoning of the territory of one of the five districts of the projected national Park – Pustynsky.
Biological reserves of bracken fern (Pteridium Aquilinum (L.) Kuhn.) in the coniferous forests of Altai Territory
Authors: Sokolova G G
Published: August 2023

The article contains information on the biological reserves of bracken ferns in coniferous forests in the Altai Territory. For the study, 2 zones were taken - the Priobsky pine forest zone and the Salair ridge zone. The predominant types of forests in this area are pine and fir forests. During the study period, the biological and operational reserves of bracken fern and the amount of annual collection in various forest conditions were determined. The studies carried out have shown an extremely uneven distribution of biological, operational and commercial reserves of bracken fern by forest types and individual regions. A possible annual harvest of bracken ferns in different types of forest is recommended, depending on the frequency of harvest in a particular area. Measures for the rational use of biological reserves of bracken fern in the Altai Territory are proposed.
Resource potential and sustainability of recreational soils in the city of Uralsk
Authors: Gumarova Zh M , Akkereyeva E K , Jussupkaliyeva Roza , Zhazykbayeva G M , Sharafiyeva Zh R
Published: August 2023

The study of the resource potential and sustainability of soils in the green areas of the city of Uralsk is necessary to determine further steps to preserve the green fund. The recreational load was studied on the territory of the Kirov Park., Zh. Moldagaliev, Isatai and Makhambet, as well as the embankment of the Chagan and Ural rivers. In soils, such characteristics as moisture content, density, water permeability, organic carbon and salinity were studied. Soil water permeability was studied by the tube method. The density of recreational soils in the city of Uralsk was studied by the cutting ring method. Additionally, studies were carried out on the buffer capacity, salinity and organic carbon of soils. These studies were carried out by conventional methods. The results of comparing data on water permeability, density, salinity and resource capacity show a tendency for their condition to deteriorate at sites experiencing a constant recreational load. The recreational load is especially critical in the territories of public gardens Zh. Moldagaliev, Isatai and Makhambet and the embankment of the Ural River in the area of the Stela memorial complex.
Increasing the profitability of production of hard-to-recover oil reserves based on the choice of a rational development system
Authors: Agishev E R
Published: August 2023

The article presents a solution to the problem of determining the most effective system for the development of hard-to-recover oil reserves confined to thin-layered clay-bearing reservoirs, based on geological and hydrodynamic modeling. The ratio of oil recovery factor and net discounted income was used as an assessment of the project efficiency. When selecting, the profile was varied - a directional well with hydraulic fracturing and a horizontal well with multi-stage hydraulic fracturing, the method of organizing the system for maintaining reservoir pressure, the density of the well grid and the technological parameters of well completion - the length of the horizontal section and the distance between the hydraulic fracturing sleeves. To confirm the results obtained, an analysis of the operation of the wells launched at the facility was carried out, which showed the convergence of the rate of decline in production rates in the absence of the involvement of the underlying horizon by a hydraulic fracture. Additionally, when choosing a site for pilot work, an option was considered to use the existing well stock to organize a reservoir pressure maintenance system while maintaining the geometry of the development element. According to the calculations, the application of the developed solutions will make it possible to double the oil recovery factor and the net discounted income of the project compared to the base case.
To calculate the maximum annual level according to the water rating curve (on example the small River Zlaya)
Authors: Akhmedova N R , Kh Aliyeva A , Naumov V A
Published: August 2023

The rating curve of water in the river is an important characteristic of the water regime. In this article, the series of maximum annual levels and discharges of the Zlaya River (hydrological post Priozerye, Kaliningrad region) are indicated; rating curves of Zlaya River for different years were constructed. It has been established that the number of maximum annual discharges of the Zlaya River after 1991 tends to decrease, while the linear trend of the maximum annual levels shows an increase. The largest positive drawdown of the rating curve of Zlaya River was recorded from the early 60s to the mid-70s of the 20th century, which, presumably, was affected by the commissioning of a large array of drained lands during this period. The results of the study can be used in conducting hydrological surveys, developing measures for water resources management.
The study of economically valuable traits of sweet pepper collection varieties and effectiveness economic evaluation of their cultivation in the conditions of protected ground in Armenia
Authors: Zh Sargsyan G , Vardanyan N S , Vardanian I V
Published: August 2023

In the conditions of an unheated film greenhouse 14 collection sweet pepper (Capsicum annuum L.) samples were studied: Darovita F1, N-62-439 (Nickerson-Zwaan), Yupiter F1, Dimentio F1, Blondi F1 (Syngenta), AVPP 0503, AVPP 0709, AVRDC-9946-2192, PBC-371, AVPP 0408, AVRDC-0701, AVPP 0910, AVPP 1115, AVPP 05483 - from genbank of AVRDC (Asian Vegetable Research and Development Center). According to the duration of the phenophases, 11 samples were assigned to the group of mid-ripening and 3 samples were classified as late-maturing. The varieties differed in shape, color, average weight of the fruit (within 76.1 to 208.4g). The total yield of variety samples varied from 8.9 to 15.9 kg/sq m, with the control variety “Sate”- 11.5 kg/sq m. Varieties AVPP 05483, N-62-439, AVPP 0503, AVRDC 0701 turned out to be the most highly productive, in which the increase to the standard was 20.9, 22.6, 33.0, 38.3% and profitability of cultivation was 125.6, 120.3, 129.1, 130.7% respectively. Variety samples from AVRDC AVPP 0503 with the name “Narinj” and AVRDC-0701 - “Loshtak” passed the State Variety Testing and are now successfully cultivated in greenhouses of Armenia.
Comparison of the minimum discharge of the Instruch river at the beginning of the 20th and 21st century
Authors: Akhmedova N R , Naumov V A
Published: August 2023

The hydrological series of the minimum annual discharges of the Instruch River (hydrological gauging station Ulyanovo, Kaliningrad region) was studied. The values of the minimum discharge rates were processed in the Mathcad environment. The characteristics of the minimum discharges (average and minimum annual, minimum 5-, 10- and 30-day discharges) of the Instruch River in 1901-1912 and 2008-2020 are determined. A comparative analysis of the characteristics of the minimum annual discharges of the river Instruch for the indicated periods.
Mineral elements and heavy metals in plant composition Pectorales species No. 2
Authors: Chevidaev V V , Bokov D O , Samylina I A , Strelyaeva A V , Rendyuk T D
Published: August 2023

The authors analyzed the elemental and mineral content of the plant composition Pectorales species No. 2 (PS No.2) which includes herbal raw materials coltsfoot leaves, plantain leaves, licorice roots by ICP-MS. 25 elements have been identified in PS No.2. The highest content was reached by potassium (2243.13 mg/kg), calcium (881.14 mg/kg) and magnesium (156,08 mg/kg). The content of lead (0.007 mg/kg), cadmium (0.0035 mg/kg), mercury (0.0011 mg/kg) and arsenic (0.0056 mg/kg) does not exceed the MPC specified in the in the State Pharmacopoeia of the Russian Federation, XIV edition.
Selection of the most prospective strains for inclusion in the composition of a biopreparation on the basis of cellulose-destroying microorganisms
Authors: Maiorov P S , Lyashenko E A , Feoktistova N A , Suldina E V , Atamanova E E
Published: August 2023

A great number of plant residues remain in the soil after harvesting almost all types of agricultural crops. At the same time, such residues mostly consist of cellulose, which can enrich the soil with feed sources for further agricultural crops. However, plants are not able to use cellulose itself, and thus great importance is given to various microorganisms involved in the cleavage of cellulose to more simple compounds. Within the framework of this work, the cellulolytic ability of 221 strains of bacteria isolated earlier from soil and peat samples was studied. The obtained data made it possible to select 35 strains with the highest cellulose activity. Most of the studied bacterial cultures had no antagonistic properties towards each other, which allows to use them together in the developed biopreparations. In conclusion, we offer a scheme for the production of experimental biopreparations to evaluate the collaborative work of selected bacterial strains directly in the field.
Populations structure and role of Hedysarum grandiflorum in the spatial organization of plant communities of petrophyte steppes
Authors: Ilyina V N , Zenkina T E , Mitroshenkova A E , Kozlovskaya O V , Senator S A
Published: August 2023

Comprehensive monitoring and assessment of the state of vegetation cover of Samara Trans-Volga show that steppe landscapes are the most vulnerable, and areas of petrophytic steppes. Rare species include Hedysarum grandiflorum Pall. This species is protected in the territory of Russia. Structural features of cenopopopulations were studied in more than 50 natural-territorial complexes. The number of individuals in populations of specific locations is usually sufficient to make a comprehensive assessment of the species at different levels of organization (organismal, population, species, and phytocoenotic). The study of cenopopopulations was carried out in 1998-2020. During the field studies, we used the method of laying test sites (stationary plots). Data on the spatial distribution of individuals were processed in the R environment (version 3.3.2) using the SPATSTAT package. The intensity of the location of individuals of the studied species was estimated using the Gaussian kernel function with boundary correction. Most of the H. grandiflorum populations known to us are (or have already been) degraded or even critical due to irrational economic exploitation of natural complexes. The random type of placement of individuals indicates favorable habitat conditions for the studied species at stationary plots. Perhaps, some tendency of pregenerative individuals to cluster is due to the mosaic location of sites suitable for seed germination (small depressions with sufficient moisture, areas not occupied by vegetation, formed under the action of exogenous factors).
Study of the method of using an electric starter to stabilize the rotational speed of a gas turbine plant
Authors: Krylova I A , Kavalerov B V
Published: August 2023

The article discusses the use of a synchronous motor as an electric starter of a gas turbine plant. A gas turbine plant is used to drive an electric generator in a power plant. It is shown that the same starter can be used in the electric motor mode to stabilize the rotational speed of the gas turbine plant. This is especially important and relevant for fast and large changes in the load of a gas turbine plant. Changing the electrical load of the power plant directly affects the load of the gas turbine plant. Since the gas turbine plant has a large time constant, it is necessary to quickly supply additional power to stabilize the rotational speed of its shaft. It is proposed to use an electric starter for this. The control of the starter by a perturbing signal is studied by means of simulation. Then the scheme of the control system is modified to determine the disturbing effect by calculation. Graphs of simulation results are presented and the results obtained are discussed.
Water removal from a gas well under different pressure conditions
Authors: Bacirheba Mugisho Joel
Published: August 2023

By looking at report analyzes as well as research, it emerges that in the decades to come, several gas field wells will see their productivity significantly reduced due to the influx of water into these operating wells. It is under these conditions that artificial lifting methods can be used to maintain the well in an economically profitable state of productivity. In the article the rate of evacuated water from a vertical tube under different pressure conditions are compared.
Analysis of dynamic response of three-span bridge using vehicle load data from Road Administration Department IV in Vietnam
Authors: Nguyen Xuan Toan , Dang Cong Thuat , Nguyen Thi Kim Loan , Nguyen Duy Thao , Tran Van Duc
Published: August 2023

In many studies, the dynamic response of bridges is influenced by various factors. Multiple factors, such as vehicle loads, road roughness, vehicle-bridge interactions, and travel speed, impact the dynamics of a three-span bridge on highways. Because the mass of the vehicle, including the cargo, fluctuates randomly, a probabilistic methodology based on the Monte Carlo method is utilized to produce random anomalies for dynamic analysis. To examine the Song Gieng bridge, data from the Road Administration Department IV on heavy vehicle loads and overloaded vehicles are utilized to produce random vehicle loads. The analytical results indicate that there is a discrepancy in the probability distribution rules between the vehicle load (input random variable) and the dynamic impact factor (output random variable). This implies that their mapping connection is not monotone. Compared with the threshold values specified in the bridge design standards of Vietnam and the United States, the dynamic impact factor obtained in this study is significantly different. These findings can provide additional guidance for practicing engineers.
Thermally induced vibration analysis of sandwich beam with metal foam core subjected to blast loading by a framework of two-unknown higher-order beam theory
Authors: Hung Tran Quang , Duc Do Minh , Tu Tran Minh
Published: August 2023

Vibrational characteristics of a sandwich beam in thermal environments subjected to blast pressure are investigated in this paper. The sandwich beam is composed of two isotropic skins and an open-cell metal foam core with either uniform or symmetric distribution of internal pores. The pressure of blast loading is modelled by Friedlander’s equation. A two-unknown higher-order beam theory combined with Hamilton’s principle is used to establish the governing equations. Navier-type solution and Newmark-beta method are applied to deal with the governing equation and obtain the dynamic responses. The efficiency and accuracy of the present study are examined through numerical examples. Effects of temperature-dependent material properties, porosity coefficient, core-to-skin thickness ratio, length-to-height ratio, and structural damping on the natural frequencies and dynamic deflection of the sandwich beam are investigated in detail.
Effect of deterioration overtime on the power spectral density of the bridge vibration responses under real traffic
Authors: Vuong-Cong Luan , Pham-Bao Toan
Published: August 2023

Working in an environment with many influencing factors can lead to the deterioration of construction. For bridges, the harshness and unpredictability of the environment can come from temperature, air humidity, wind, soil, and vehicle loads. Over time, these factors cause the quality of the bridge to degrade. Because there are too many factors acting simultaneously with varying degrees of influence, this paper only focuses on the parameter that represents the degradation over time, regardless of which factor the degradation is due to. The proposed parameter has a one-way variation with time, and its change is a sensitive indicator to operation process of the bridge. This parameter is calculated using measurement data of the bridge’s vibration over time and in response to actual traffic loads. This demonstrates the viability of this idea in the experiment.
Maintenance modeling and cost assessment for repaired reinforced concrete structures exposed to chloride attack in coastal areas in Vietnam
Authors: Truong Q C , Nguyen Q T , Soueidy C P , Bastidas-Arteaga E
Published: August 2023

One of the primary causes that can reduce the lifespan of concrete structures is chloride-induced corrosion of reinforcing steel. Recent research has shown that material properties, exposure conditions and climatic conditions have a significant influence on the structural deterioration of reinforced concrete (RC) structures, especially in marine environments. The objective of this paper is to predict the durability of RC structures damaged by chloride-induced corrosion in near-shore environments in Vietnam, considering regular repair activities. A two-dimensional model of chloride penetration in square cross-section RC columns repaired by cover replacement techniques is studied. Two repair methods with different shapes (orthogonal and circular) are considered. The effects of the different repair methods on the life span of structures are investigated in case studies in Vietnam that consider the variations of annual temperature and humidity in three coastal areas such as Danang, Haiphong, and Ho Chi Minh City. Finally, maintenance and repair costs during the lifetime of structures are calculated for each case. The study suggests that for RC structures exposed to two-dimensional chloride ingress, the most critical areas for assessing chloride concentration, predicting corrosion initiation, and planning repair schedules are the corners of the columns. In addition, the chloride-induced corrosion process is strongly influenced by the local weather conditions, especially in areas with high humidity. The repair method with circular concrete replacement seems to be more efficient in terms of maintenance schedule and cost than the repair method with orthogonal concrete replacement.
Analysis of bridge displacement using GNSS time-series data
Authors: Vu Ngoc Quang , Le Thi Nhung , Luong Ngoc Dung
Published: August 2023

Analysis and identifying the displacement characteristics play a key role in timely monitoring and detecting the physical responses of the bridge to ensure the safety of the human and structure. Many previous kinds of research used GNSS data to identify displacement and oscillation modelling of the bridge with different algorithms. This study uses GNSS time-series data to determine linear displacement and model oscillation of the bridge using a procedure including filtering outliers, linear regression, and sin function to identify amplitude in three directions, the plane displacement velocity, spatial displacement velocity, and vibration model of the bridge. The data in the research in the GNSS time-series data from three P5 GNSS receivers of the CHC brand on the Dachongyong bridge in Nanning, China with 1646 observations, at one-hour sample intervals in 68 consecutive days. The plane and spatial velocity of the three points DCQ01, DCQ02, and DCQ03 is 0.0181 mm/h, 0.0185 mm/h; 0.0114 mm/h, 0.0173 mm/h; and 0.0071 mm/h, 0.0082 mm/h respectively. The study results are significant in analyzing and identifying the bridge’s displacement characteristics.
Gamification in infrastructure and its application in Vietnam
Authors: Pham Bach Van , Bui Quynh-Anh Thi
Published: August 2023

In the Fourth Industrial Revolution, innovative approaches that are emerging to solve traditional problems are regularly updated and improved. Prominent among them is the gamification application in the infrastructure construction industry. This is an intuitive simulation tool that brings a high level of experience and efficiency. The article presented an overview of the gamification application in infrastructure. It can be seen that with the development of modern game engine and new technologies such as Building Information Modelling (BIM), Virtual Reality (VR), Mixed Reality (MR), Augmented Reality (AR), digital twin, gamification is used in different phases of a project such as design, construction and operation. Furthermore, the article also provides an assessment of opportunities and challenges when applying gamification to the infrastructure construction in Vietnam. Furthermore, some preliminary suggestions to improve the application efficiency are also made.