bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of the Angle of the Reverse Shoulder on the Performance of Premium Casing Connection
Authors: Hao Long , Mu Meng 
Published: January 2021

Abstract
The premium casing connection is composed of three parts: the main sealing structure, the reverse shoulder structure and the thread. The angle θ of the reverse shoulder has an important influence on the strength and sealing performance of the premium casing connection. Based on the idea of factor rotation method, the influence of parameter θ on the maximum contact pressure of the main sealing surface of the premium casing connection, the contact pressure of the shoulder surface and the internal stress of the connection is studied through finite element simulation experiments. The results show that the greater the angle of the reverse shoulder, the better the sealing performance of the connection, but the worse the anti-torsion ability of the connection.
Kinematics Analysis and Trajectory Planning of Polishing Six-axis Robot
Authors: Lu Ye , Wang Kai 
Published: January 2021

Abstract
With the development of intelligent manufacturing, due to the low production efficiency and poor production environment of manual polishing, which is gradually replaced by the polishing robot. Take the polishing robot as the research object in this paper, a three-dimensional model of the robot with the end effector is established. The kinematics is modeled, solved and simulated with the D-H method and MATLAB Robotics Toolbox. The trajectory planning of the robot in joint space and cartesian space is analyzed and simulated.
Concentrating solar power multi-effect desalination in Al Khobar, Saudi Arabia
Authors: Boretti A , Castelletto S , Al-Kouz W , Nayfeh J 
Published: January 2021

Abstract
As about two-thirds of the thermal energy to the power cycle of a concentrated solar power plant is dumped to the condenser, typically air or evaporative cooling, there is the opportunity to achieve energy savings by using a multi-effect distillation system to condensate the steam and at the same time produce desalinized water. Preliminary design considerations and computations for a concentrated solar power plant located in Al Khobar, Saudi Arabia, are here proposed. The solar field has an aperture of 1,230,000 m2, it uses oil as the receiver fluid, it uses a six hours’ thermal energy storage by molten salt, and it features a 140 MW turbine. It is expected production of up to 413 GWh of electricity annually, for a capacity factor of 0.36, by using an air-cooled condenser. Adoption of a glass enclosure and a multi-effect distillation plant replacing the air-cooled condenser may permit the same electricity production plus the production of desalinized water in an environment protected by sand and dust.
Methods for verification of groundwater flow simulators (case study: Jakarta groundwater basin in the urban villages of Jatiluhur and Jatirangga, Bekasi City)
Authors: Rahmawati T , Putri G L , Marthanty D R , Zulkarnain F , Priadi C R 
Published: January 2021

Abstract
Limited access to clean water leads to residents extracting groundwater through dug wells or boreholes, which in turn results in groundwater becoming contaminated. Groundwater flow simulation of the Jakarta basin, which has been previously modeled with the Groundwater Modeling System 10.3, can be used as a basis for simulating groundwater flow pollution. Before simulating the groundwater flow pollution, the groundwater flow simulator needs to be verified to examine whether simulators and conditions in the field correspond to the water table level. This study demonstrated the methodology used for verification of the simulator in research. Verification was done using the Chi-square method. The results revealed that calculated Chi-square values were larger than Chi-square table values for the two urban villages of Jatiluhur and Jatirangga. The value of calculated Chi-square value for Jatiluhur was 17.3, whereas it was 7.81 in the Chi-square table. In Jatirangga, the calculated Chi-square value was 37.23, whereas it was 14.1 in the Chi-square. Results indicated that the simulation was not in accordance with the actual water table level. This discordance can occur since it necessary to update the data on groundwater flow simulation results with bore log data or to verify the hydrodynamic conditions of the study area.
Health risk analysis of nitrite, nitrate, and heavy metal pollution in groundwater near landfill area: A case study of the Sumur Batu village in Bekasi, Indonesia
Authors: Pratiwi WH , Putri GL , Pratama MA , Zulkarnain F , Priadi CR 
Published: January 2021

Abstract
Previous studies state that improper landfill or waste management is one of the main causes of nitrite, nitrate, and heavy metal contamination in groundwater. In Bekasi, Indonesia, 70% of the population depends on groundwater for daily use, including the residents of Sumur Batu. The village of Sumur Batu is located adjacent to two landfills, namely, the Bantar Gebang landfill, which is the largest landfill in Indonesia, and the Sumur Batu landfill. This research analyzed the health risk of drinking groundwater that may have been contaminated by nitrite, nitrate, and heavy metals. Data processing was performed separately for different age groups: infants, children, and adults. The results showed that there is a risk of NO2 exposure in all age groups when groundwater is used as a source of drinking water in Sumur Batu. Because the region is directly bordered by a landfill area and the community is highly dependent on groundwater, as long as access to water services is not guaranteed, the quality of groundwater in this area needs to be monitored.
Parameter identification of capacitive transfer system based on Fitting Algorithm
Authors: Chen Chen , Li Chenhui , Liao Chenglin 
Published: January 2021

Abstract
At present, in the wireless power transfer (WPT) of electric vehicle (EV), inductive power transfer (IPT) is still the main method. However, capacitive power transfer (CPT) has the advantages of no eddy current loss of coupling mechanism and light weight, which make it become a new research hotspot in the charging application of EV. But CPT system has high working frequency and sensitive parameters, therefore, in practical application, it is necessary to identify important parameters such as coupling capacitance and load. But at present, there are few identification methods for parameters of CPT. In this paper, a multi-parameter identification algorithm is proposed for capacitive wireless charging technology. Based on Vector Fitting algorithm and network synthesis principle, multi-parameter identification is realized. But in order to be widely used in practice, some parameters in circuit model are considered as known constraint. This can ensure that the proposed algorithm can not only realize multi-parameter identification, but also ensure the identification accuracy of system parameters in practical application.
Discussion on Some Problems of Bridge Scour in Both Experiment and Simulation
Authors: Wang Wei-zheng , Wei Song , Duan Haipeng , Cao Jing , Jiang Yuxi 
Published: January 2021

Abstract
The scour of bridge piers is one of the important factors causing bridge damage. The research on the scour mechanism of bridge pier includes two main ways: physical experiment and numerical simulation. In this paper, the research progress in recent decades is summarized, and the influencing factors that include the Reynolds number, pier shape in physical experiments and the selection of models such as RANS, LES, DES in numerical simulation are sorted out. Both physical experiment and numerical simulation are used to investigate the depth of scour hole and flow structures. Finally, it is pointed out that the stress characteristics generated by scouring flow are one of the directions for further research.
The water footprint of permeable sidewalk pavement in China
Authors: Wang Weixia , Chang Yuan 
Published: January 2021

Abstract
As China continues to urbanize, the area of impervious surface in city is increasing, leading to serious problems of water logging, water resources shortage, and water quality deterioration. Thus, the comprehensive management of urban water resource is facing severe challenges. Based on the concept of “sponge city”, this study employed the life cycle assessment (LCA) modeling approach to calculate the water resource footprint of permeable sidewalk pavement in Beijing, China, and compared the result with conventional concrete brick pavement. The results show that the water consumption of 1-m2 permeable pavement is 253kg, 19% higher than that of concrete brick pavement (212kg). Given that the average annual precipitation of Beijing is 597mm, 1-m2 permeable pavement can collect 5972kg of water resources throughout its 10-year life cycle, enabling a net water-saving benefit of 5.7 tons.
Study on the Weakening Performance of Fiber Concrete under the Action of Acid Rain-sewage Coupling Erosion
Authors: Wu Duo 
Published: January 2021

Abstract
Unfavorable environments such as acid rain corrosion and sewage erosion will have a great impact on the mechanical properties and durability of concrete structures. In order to further explore the weakening performance of concrete structures in harsh environments such as acid rain and sewage, plain concrete, basalt concrete with 0.08%, 0.1%, and 0.12% fiber content were adopted for comparative analysis. The weakening of compressive and flexural strength of concrete with different fiber content under sewage erosion and acid rain corrosion were investigated. The results of this paper can provide reference value for further research on the deterioration performance and life prediction of structures under long service life.
Unified solutions on axial bearing capacity of T-shaped concrete-filled steel tube short columns with binding bars
Authors: Ge Qingyun , Yang Fulian , Dong Wenxiu , Bian Zhu 
Published: January 2021

Abstract
Based on the unified strength theory, according to the characteristics of axial bearing capacity of T-shaped concrete-filled steel tubular stub short columns with binding bars, the cross shaped section was divided into 3 rectangular sections which have binding bars and one rectangular section which has no bars. Considering intermediate principal stress, the ration of width to thickness of pipe to the bearing capacity of steel tube was in consideration too, the paper analyzed force mechanism. In the end, the mathematical formulation of bearing capacity for the T-shaped concrete-filled steel tube stub column with binding bars was obtained. The formula calculation values are in good agreement with the test value of the relevant literature.
Temperature and Stress Fields of Anchorage Mass Concrete of a Suspension Bridge
Authors: Chen Xianyu 
Published: January 2021

Abstract
Because of its huge volume, the method of block and layer pouring is usually used in the construction process of suspension bridge anchorage. In order to avoid the temperature cracks of mass concrete caused by hydration heat in the construction process, a three-dimensional finite element model is established based on the anchorage of a suspension bridge. The influences of the temperature of mixture placing to mold, the thickness of layers, the ambient temperature and the maintenance measures on the temperature at the centre, the temperature difference between the top surface and middle point and the tensile stresses at the surface are analyzed. The results show that the temperature at the centre, the temperature difference between the top surface and middle point increase with the increase of the temperature of mixture placing to mold and the thickness of layers are positively correlated. When the temperature of mixture placing to mold changes from 15°C to 35°C, the temperature at the centre increases by 19.06°C, the temperature difference between the top surface and middle point increases by 10.85°C, and the tensile stresses at the surface increases by 0.72 MPa; when the thickness of layers increases from 1 m to 3 m, the temperature at the centre increases by 15.46°C, the temperature difference between the top surface and middle point increases by 16.87°C, and the tensile stresses at the surface increases by 1.51 MPa. The temperature difference between the top surface and middle point decrease with the increase of the ambient temperature, while the temperature at the centre increases with the increase of the ambient temperature. Moreover, the temperature difference between the top surface and middle point decrease with the improvement of curing conditions. Therefore, in the actual project, reducing the temperature of mixture placing to mold, the reasonable layer thickness, the suitable ambient temperature and good maintenance measures, which can effectively reduce the cracking risk of mass concrete.
Influence of laser steel quenching on the service life of friction units
Authors: Biryukov V P , Savin A P , Prince A N 
Published: January 2021

Abstract
This paper presents the results of metallographic and tribological studies of 65Mn steel samples with laser and bulk quenching. A full factorial experiment was performed that allowed calculating the depth and width of the quenching zones with an error of no more than 3.28%. It is shown that laser hardening reduces the friction coefficients by 2-3 times and increases the jamming load compared to bulk steel quenching.
Impact of cracks on vibration parameters and lifetime of hydraulic units
Authors: Georgievskaia Evgeniia 
Published: January 2021

Abstract
One of the key factors determining the hydraulic unit reliability and lifetime is the current technical state of the runner and, first and foremost, its lack of dangerous cracks. Dynamic load throughout the mode range affects the crack occurrence and development. Blade system crack formation process depends heavily on actual equipment operating modes. Yet, modern hydraulic unit diagnostics systems tend not to record crack formation on its early stages. As a result, routine maintenance often reveals long cracks which require significant financial and time resources to repair. Vibration-based diagnostics systems reveal cracks during operation ineffectively: calculations of the Francis (hydraulic) turbine’s runner prove that. High structural rigidity and specific eigenforms don’t permit correlating the blade dynamics to measured vibration parameters. Analytic approach based on calculating fatigue strength and fracture mechanics methods could solve the problem mentioned above.
Ultrasonic detection of manufacturing defects in multilayer composite structures
Authors: Kokurov A M , Subbotin D E 
Published: January 2021

Abstract
The authors have considered practical aspects of the use of ultrasonic method for identification of foreign objects in the structure of laminated composite. The paper presents the results of laboratory investigations aimed at determination of shape and dimensions of artificially created defects and the analysis of specific aspects of ultrasonic detection of fragments of prepreg protective coating.
Monitoring of the NPP equipment stressed state according to indirect measurements data
Authors: Maslov S V , Kukshinov A I 
Published: January 2021

Abstract
The method for monitoring the stress state of the NPP equipment internal surfaces is considered, based on the results of strain gauge measurements obtained for the outer surface of the structure. The temperatures of the internal surfaces are found from thermoelasticity inverse problem solutions, the stress state is determined by the solution of direct problems.
On the issue of improving the reliability of machines for open-pit mining operations with expiring or expired standard exploitation period
Authors: Pobegailo P A , Ilyina A N , Kritckij D Y 
Published: January 2021

Abstract

The present paper presents our new results related to the research aimed at improving reliability and safety, and reducing operating costs of open-pit mining machines. The main attention was paid by us to the failures of mining equipment. Our main focus has been on machines with the expiring or already expired standard exploitation period, which, however, are not utilized, but continue their work. The failures of mining machines have been collected by us at a number of enterprises in Russia over the past few years. After that, we analyzed and processed them. During the analysis, these initial data were presented by us in the form of frequency graphs. Further, these discrete graphs were “transferred” by us into continuous by means of harmonic analysis methods -using the Fourier series and mathematical package MATLAB. According to the results of the work, it was found out that the number of failures is growing. This can be explained by the rhythm of the nature of the occurrence of failures and connection between the failures and the physiological state of the people working and operating these machines, which was previously not given due attention.
Obtaining gypsum products from gypsum dihydrate in a microwave field
Authors: Sokov Victor , Dmitriev Nikita 
Published: January 2021

Abstract
The increasing requirements for environmental protection make the development of energy-efficient technologies for building materials urgent, combining a number of stages in the production of materials into one technological redistribution using more efficient methods of their heat treatment. The article discusses the possibility of obtaining gypsum products from two-water gypsum stone, bypassing the production of gypsum binder, using microwave heating as the most effective and convenient of the existing heating methods, which does not require direct connection of external electrodes to the internal electrodes of the mold, to which the material can burn. rendering the electrodes unusable. Due to the combination of the processes of binder production (dehydration of ground gypsum dihydrate with the elimination of 1.5 water molecules) and the finished product (the reaction of semi-aqueous gypsum with water to form a monolith of gypsum dihydrate) in one apparatus, the total production time of the product is greatly reduced, starting from the extraction of quarries.
Technical and economic analysis of the proposed method of utilization of asphalt resin paraffin deposits (ARPD) in the composition of organomineral waterproofing material
Authors: Abilbek Zhanyl , Zhabagiev Aslan , Koptileuov Bolat , Kelmagambetov Nurlybek , Erzhanova Aigul 
Published: January 2021

Abstract
Currently, for many construction industries promising becomes the creation of waterproofing materials on the basis of integrated management natural oily raw material, as well as improvement of traditional materials. Choice of material depends on the working conditions of a hydraulic installation, categories of reliability construction, its structures, the availability of local building materials, method of work and of technical and economic indices of construction. In this paper described economic and technical efficiency of using asphalt resinous paraffin deposits as a main composition of organomineral material for antifiltration screen. In this paper described technology of preparing oil waste sludge pit, where asantifiltration screen is used polymerorganic screen based on asphalt resin paraffin deposits (ARPD) and polymer material. Processing of oil waste and reducing their formation is a significant problem from the ecological point of view and requires new ecological and technological solutions. In this research paper analyzes the results of world practical experiments on the application of waste and presents technical solutions for the use of waste that are suitable for future application. The feature of this work is obtaining waterproofing materials based on asphalt – resin -paraffin deposits and polymer, moreover the improvement of its physicochemical properties. The results of experimental laboratory testing of the effects of aggressive components of waste on the physical and mechanical properties of the material made from polymerorganic and cement mixture are presented.
Analysis of the mode of squeezing out excess water for mixing concrete mixture in the process of peristaltic compaction
Authors: Khasanov Bakhridin , Vatin Nikolai , Mirzaev Temur , Suyunov Abdugani , Radjabov Mirzokhid 
Published: January 2021

Abstract
For the formation of a mixture of a given workability of the optimal conditions for the hydration of the binder, it is necessary to use concrete mixtures with a high moisture content. However, in order to optimize the properties of concrete, to obtain ultimate strength, it is necessary to remove excess mixing water. The physical and mechanical properties of concrete will be in direct proportion to the amount of residual mixing water [1, 2]. If the concrete mixture is compacted by squeezing out a certain amount of free water, then the strength of concrete will be in inverse functional dependence on the residual W/C, since it is this that determines the porosity of cement stone and concrete. Therefore, in order to obtain concrete of extremely high strength and density, the pre-laid mixture must be additionally compacted under conditions of maximum concrete dehydration. With complete mold tightness, the mixture is compacted only due to a slight decrease in the volume of entrained air, i.e. the effect of vibro-shock-peristaltic compaction will be insignificant. This effect will increase with an increase in the water permeability of the mold walls, since in the presence of filtration holes, free water under the action of the difference in pressure inside the mold and outside it will begin to move towards the filtration holes [3].
Effective thermal insulation based on recycled polyethylene
Authors: Semenov Vyacheslav , Zhukov Alexey , Pilipenko Anton , Mednikova Elizaveta 
Published: January 2021

Abstract
Foam polyethylene is an effective insulating material in systems of frame and frameless buildings, floating floors, and technical thermal insulation. The products based on this material enable to obtain seamless insulating shells, which significantly reduce heat loss through joints. The use of recycled polyethylene for the production of foamed polyethylene is advisable both from the point of reducing the cost of the material itself, and from the point of preserving the environment. The aim of the work was to assess the possibility of using recycled polyethylene for the manufacture of foamed polyethylene, taking into account the possible application of modifiers and varying the foaming modes. The results of the experiment made it possible to evaluate the influence of prescription and technological factors on the properties of products. The implementation of optimization solutions made it possible to construct a nomogram that allows predicting the properties of products and establishing the optimal costs of the main components. The optimal interval of consumption of recycled polyethylene has been established, which is 20 … 25%. The properties of such a material practically do not differ from the properties of products made from foamed polyethylene that enables its application in all insulation systems where pure foamed polyethylene is used.
Comparison of Approaches to Ensuring the Radon Safety of Designed Buildings in Russia and USA
Authors: Shubin I L , Bakaeva N V , Kalaydo A V 
Published: January 2021

Abstract
Indoor radon and its progeny exposure poses a significant threat to the population collective health of most countries in the world. Modern construction technologies make it possible to regulate the radon entry from the soil within a wide range, but at present there is no universal approach to ensuring the radon safety of buildings. This situation is partly explained by the multifactorial nature of the process of the radon situation formation in the lower floor premises, which does not allow to unambiguously establishing the dominant mechanism of radon entry. The article discusses technologies for ensuring the radon safety of buildings in Russia and the United States, shows their fundamental differences, advantages and disadvantages.