bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on suppressing brittle fracture and implementing ductile mode cutting for improving surface quality at silicon wafers manufacturing
Authors: Kovalchenko A M , Pashchenko E O , Savchenko D O 
Published: October 2021

Abstract
Single crystal silicon is an important basic material used to manufacture electronic and photovoltaic devices. Ductile mode of diamond wire sawing is a promising method for silicon wafering in order to produce wafers with minimal surface damage. To achieve ductile mode, the correct applying of cutting parameters and careful wire design is necessary. This study investigates the scratching of monocrystalline silicon by the abrasive particles of different geometry, which simulates the material removal process in diamond wire sawing. Diamonds, crushed and spherical tungsten carbide (WC) particles served as abrasives. Experiments show that spherical abrasives enhance ductile mode cutting significantly decreasing brittle damage when compared to irregular shape particles. Spherical WC particles permit to increase the critical load and critical cut depth of ductile-to-brittle transition from 5 to 10 times. The depth of the damaged subsurface layer decreased from 5 µm to 0.2 µm due to the absence of brittle cracks. A uniform regular distribution and appropriate suitable density of abrasive particles is obligatory for cracking reduction. For that, the method of diamond particles uniform deposition with the controlled density by a polymer binder combining high modulus and adhesive capacity with good flexibility was elaborated. The method includes preliminary diamond particles fixation on a thin resin layer providing high uniformity and subsequent strong fixation by a thicker resin layer. The research on ovalization of diamond particles was performed for smoothening cutting edges. The method is based on the activation of the graphitization process at sharp edges of particles under the action of metal salts at increased temperatures.
Research and application of supramolecular gel plugging agent in abnormal pressure reservoir
Authors: Baletabieke B , Gu Y X , Zhou T , Duan D X , Liu J T , Kong X J , Qian F , Li W J , Zhong Z , Xiang Y , Jing N , Li J Y 
Published: October 2021

Abstract
The Aktobe project is the largest oil and gas producing area of PetroChina in Central Asia. However, after years of exploitation, the pressure of the reservoir has dropped, making it difficult to increase the production of a single well. Both the Kenkyak block and North Troyes block of the project have induced fractured leakage, and frequent leakage affects safe and efficient drilling and completion operations and production. Therefore, the research on leakage prevention and control technology is very necessary. This article focuses on the characteristics of the cracks in the high-pressure area of the Kenkyak block and the cracks in the low-pressure area of the North Troyes block. Aiming at the fracture characteristics of the high-pressure zone in the Kenkyak block and the low-pressure zone in North Troyes block, and taking advantage of the synergistic effect of supramolecules, a supramolecular plugging-while-drilling agent was developed based on the deformable fiber composite gel. It forms a strong adhesion plugging layer on the inner wall of the leakage channel through the strong adhesion force, and it achieves a good plugging effect. The 300-500mD sand disc bearing pressure could reach 700psi when adding 3% agent, and the bearing pressure of 3-5D permeability sand disc could reach above 450psi. A supramolecular static plugging agent was also developed based on the dilatant gel. It is rich in strong shear reversible gel with supramolecular structure, which guarantees its pumpability and plugging performance. The effective rate of one-time plugging is over 80%, and the viscosity is greatly reduced after the gel is broken for 72hr, which benefits the reservoir protection.
Electrical conductivity of polymer/carbon nanofillers composites
Authors: Kostromin S , Bronnikov S 
Published: October 2021

Abstract
Using a broadband dielectric spectrometry we studied the effect of carbon nanofillers (CN) with various aspect ratio (fullerene C60, multi-walled carbon nanotubes (MWCNT), reduced graphene oxide (rGO) and hybrid rGO:MWCNT nanofillers) on the electrical conductivity of the polyazomethine-based nanocomposites. One-dimensional MWCNTs with high aspect ratio were shown to be the most effective CN for fabrication of polymer-based nanocomposites with enhanced electrical conductivity.
Fatigue detection and analysis of drilling tools based on metal magnetic memory method
Authors: Zhang J W , Fan J C 
Published: October 2021

Abstract
With the vigorous development of offshore oil and gas resources in the world, underwater extended reach horizontal wells have been widely used. However, due to the complicated stress and serious corrosion of drill pipes in horizontal wells, drill pipes are vulnerable to damage. After a period of service at sea, some drill tools will be placed in coastal areas for a long time. The cumulative fatigue of drilling tools is not easy to master. In the past year or two, drilling tool failure has become more and more frequent. In order to evaluate the fatigue of drilling tools in different periods and master the quantitative fatigue of drilling tools, the metal magnetic memory method has its unique advantages in detecting the stress concentration and early damage of ferromagnetic materials. The self-developed metal magnetic memory detection device is used to detect the drilling tools in the drilling tool base. The results show that the gradient peak value and ladder are used to detect the drilling tools in the drilling tool base. The average degree can be used to classify the fatigue of drilling tools, and the metal magnetic memory method is more than sensitive to various defects of drilling tools, such as penetration, internal corrosion, external corrosion, wall thickness thinning, etc.
Three- dimensional numerical simulation analysis of the influence of structural parameters on the performance of air ejector
Authors: Han L F , Liu T J , Li L , Liu D Q 
Published: October 2021

Abstract
Nowadays, CFD technology has become the third tool to study hydrodynamics problems after theoretical analysis and experimental research, especially in dealing with and solving complex engineering problems such as supersonic. In this paper, using the method of control variables, the system studied a type air ejector structure parameters within a certain range changes affect the performance of the work by means of FLUENT, at the same time, the optimal combination of the structural parameters are given, then three dimensional numerical simulation of the optimal combination model, and the simulation value and experiment value has carried on the contrast and analysis, Compared with the two-dimensional and axisymmetric model, Three-dimensional calculation model is more reliable and reasonable.
Experimental research on shear performance of single bolt joints of bamboo curtain plywood
Authors: Tang G , Wu X N , Sun P , Yang C T 
Published: October 2021

Abstract
This paper focuses on the shear resistance of the bolted connection between steel plate and bamboo curtain plywood. From the fifteen groups of specimens, the performance grade, bolt diameter and end distance of bolts have an influence on the ultimate bearing capacity of joints and the yield load of joints and the yield load is 65%∼75% of the ultimate load. The initial stiffness of the node increases with the bolt diameter increasing. Provide certain materials and theoretical references for bamboo in the future design and research.
Analysis of aging status of silicone rubber insulation material and research progress of its repair countermeasures
Authors: Li B , Huang H , Fan L , Pan G X , Tan Z , Li F , Xie X W , Zhang Z J 
Published: October 2021

Abstract
Due to its good hydrophobicity and hydrophobicity migration, silicone rubber can be used as umbrella sheath of insulators. With the continuous deterioration of environmental conditions, silicone rubber insulators in the process of power grid operation are vulnerable to a variety of environmental factors, such as humidity, partial discharge, ultraviolet radiation, icing and so on, which lead to a significant decline in hydrophobicity, mechanical properties and electrical properties, and bring serious threats to the safe operation of power grid. At present, the anti-pollution flashover mode of power grid power transmission and transformation equipment, which takes cleaning as the main method, can-not adapt to the current power grid operation environment and the impact of harsh environment, resulting in frequent power grid safety accidents. This paper summarizes the influencing factors, aging mechanism and evaluation methods of aging degree of silicone rubber insulators at present, and how to repair aging insulators and improve their anti-pollution flashover performance. Finally, the effective repair of aging silicone rubber insulator is summarized and prospected, the aging factors of insulator in specific environment are analysed, and corresponding countermeasures are taken to repair, which lays a good theoretical foundation for the future research of silicone rubber insulation materials.
Development of ideal processing parameters for powder bed fusion system processing of AlSi10Mg using design of experiments
Authors: Mathe N R 
Published: October 2021

Abstract
The additive manufacturing of aluminium alloys has gained great interest in the transport industry in the past 10 years. This is mainly due to the lightweight and good strength that these alloys offer especially for applications in aerospace and other related industries. However, there is a drawback in using these alloys especially the parts produced by additive manufacturing as they have to be heat treated before application to relieve residual stresses caused by the fast heating and cooling experienced during powder bed fusion (PBF) fabrication. Most of the current PBF metal system offer a variety of processing parameters for part building, however AM uptake and industrial implementation is still slow due to restrictions of the laser power and laser interaction time that are slow and thus the parts take long to produce. Seeing this lag in the market, the CSIR has produced a high speed and high power PBF machine with a build platform larger than the currently available commercial systems. This system allows for the faster production of parts due to its higher consolidation rate and it has already been validated for aluminium alloys, specifically AlSi10Mg. The properties evaluated were microstructure and hardness, which found to be comparable to commercial PBF machines. The samples were analysed for microstructure, mechanical properties using tensile testing procedure. In order to determine that ideal processing window, the response surface methods was used on the Stat-Ease Design Expert software using ultimate tensile strength, elongation and hardness as outputs. Based on the data analysed, the processing window was narrowed to 1400 W laser power and 1.63 – 1.95 s interaction time.
Effect of powder particle size on performances of SiC ceramic balls
Authors: Shi X M , Wang Q , Cheng Y Y , Zhang L , Zheng Y S , Zhang L J , Ren L H , Shi G P 
Published: October 2021

Abstract
The silicon carbide ceramic balls were prepared with different mean particle sizes of 0.5μm and 1.0μm. The powder particle size’s impacts on sintering density, crushing load ratio, hardness, fracture toughness, surface quality and microstructure of ceramic balls were investigated. The results show that the hardness and sintering density with different powder particle sizes were similar. Ceramic balls prepared with finer powder whose mean particle sizes 0.5μm are observed with better mechanical properties and structural homogeneity. The sintering density of ceramic balls with mean particle sizes 0.5μm is 3.118g/cm3, the average of Vickers hardness, average crushing load ratio and fracture toughness is HV2125, 60.6% and 3.22MPa/m1/2.
Corrosion and mechanical behavior of 17G1S-U pipeline steel and its weld joint of in the terms simulating operational conditions
Authors: Nyrkova L I , Prokopchuk S M , Goncharenko L V , Osadchuk S O 
Published: October 2021

Abstract
Corrosion and mechanical behavior of weld joint samples of the straight-weld pipe of 17G1S-U pipeline steel in the conditions simulating the operating conditions of internal and external corrosion has been studied. It is shown that the initiation of local corrosion of welded joints from the inner surface of the pipeline is due to thin-film corrosion in a two-phase medium (hydrocarbon-water) under deformation conditions. The depth of local damages of the base metal and weld metal can reach 0.337 mm and 0.381 mm. Stress corrosion cracking is a danger for the outer surface which is under cathodic protection. Maintaining the potential at the level of the maximum protective potential -1050 mV increases the stress corrosion cracking inclination of pipeline 17G1S-U steel and its weld joint, due to deterioration of the plastic properties of the metal during longtime exposure at cathodic polarization: decreasing in the relative elongation of the base metal is equal near 11 %, weld joint – by 20%. The KS susceptibility, estimated by the KS coefficient, under these conditions is equal to 1.8 for 17G1S-U steel, 1.5 for weld joint.
Influence of welding sequence on the mechanical properties of a latticed shell formed by orthogonal and oblique members
Authors: Wang Y M , Sang X X , Ju J S , Zhang H D , Fu Y Q 
Published: October 2021

Abstract
With the development of economy and the improvement of people’s aesthetic level, large-span latticed shells are increasingly used. Such structures are commonly large in volume and huge in welding. In order to select an optimum welding sequence and avoid correcting complex welding deformation, a latticed shell formed by orthogonal and oblique members was taken as the research object in this paper. The finite element models of single and whole latticed shells were established respectively, and according to the equal deformation principle, the influence of different welding sequence on the deformation and internal force of the structure in each construction stage was quantitatively analyzed. The results show that in the welding and assembling stage of small assembling units in the single latticed shell, welding sequence has the greatest impact on the longitudinal deformation, and the change rate of the longitudinal deformation is up to 83.63%; whereas in the tension, sliding and closure stages of each piece of the latticed shell, the transverse deformation is most affected by welding sequence, and the change rate is 33.05%; in different construction stages, the axial stress of the latticed shell is less vulnerable to welding sequence. Furthermore, it is feasible to control the welding shrinkage deformation by selecting a reasonable welding sequence, and the symmetrical welding sequence from both ends to the middle should be adopted during construction.
Effect of carbon source type on phosphorus removal efficiency of MBBR and characteristics of fluorescent substances in water
Authors: Sun J X , Wang M , Zhang X , Zhang Y T , Huang C , Wan L 
Published: October 2021

Abstract
In this paper, Moving Bed Bioreactor (MBBR) reactor was used as the research object to explore the effects of carbon source type on phosphorus removal performance of MBBR system and the changes of microbial metabolic characteristics in typical cycles. The results showed that the absorption and release of phosphorus by sodium propionate and starch were obvious. The accumulation and degradation of PHA and glycogen were observed in the three reactors, and PHA was prior to glycogen decomposition. When sodium acetate was used as carbon source, glycogen decreased during the stationary phase, and the other two did not change significantly. The intensity of fluorescent substances varies greatly with the type of carbon source. The fluorescent substances in the effluent are mainly tyrosine-like and protein-like substances, fulvic acid-like substances and humic acid-like substances. Therefore, the suitable carbon source type should be selected according to the microbial characteristics in the water treatment process to improve the treatment efficiency.
Evaluation of thermal control performance of phase change materials for thermal shock protection of electronics
Authors: Yang X H , Huang C H , Ke H B , Chen L , Song P 
Published: October 2021

AbstractPhase change materials have important application value in the fields of heat storage, cold storage, and thermal shock protection of electronic chips. In particular, in the field of chip thermal shock protection, phase change materials can use the solid-liquid phase change process to absorb a large amount of latent heat, thereby suppressing the temperature rise of the chip and preventing it from overheating. At present, there are mainly three types of common phase change materials: organic, inorganic and metallic phase change materials. There exists significant difference in the thermophysical properties of the three types of materials, and their thermal control performance also have their own characteristics. This paper sorts out the main thermophysical data of the three types of phase change materials. Through theoretical modeling and analysis, the thermal control performance of these materials is quantitatively evaluated and compared. For typical chip thermal shock conditions, the three types of phase change materials are compared, and their typical characteristics are intuitively displayed. The research results can serve as value reference for the development of phase change thermal control technology for chips.
Experimental research on thermoelectric application characteristics of thermobattery
Authors: Xiao L X , He Y T , Li L 
Published: October 2021

Abstract
In this work, experimental research was carried out to investigate the conversion output characteristics of thermobattery. The results showed that under the same temperature difference, the open-circuit voltage of the thermobattery showed a tendency of first increasing and then decreasing with the increase of hot end temperature. Under hot-end temperature of 95°C, the output open-circuit voltage reached the maximum. In addition, there was a maximum output point for the thermobattery. Regarding the thermobattery (TGM-287-1.4-1.5), its output power reached the maximum when the load resistance was 9Ω. This research provides a theoretical and experimental basis for the optimal design of thermoelectric power generation system.
A balancing control method by considering lithium batteries state of charge
Authors: Li P P , Jia Y F , Yang Z X , Song Z Z , Xiong Y X , Cheng M M 
Published: October 2021

Abstract
In order to quickly and accurately reduce the inconsistency of charge between lithium battery and prolong the service life of lithium battery, a balancing control method for lithium batteries state of charge (SOC) is proposed in this paper. The difference of each adjacent battery pack in the series lithium batteries and the difference of each adjacent battery pack in each monomer lithium battery are used as the equalization criteria, a bi-directional energy flow topology circuit is constructed using inductor as energy storage element. The magnitude and direction of the equalization current are controlled, and the balancing control of the whole lithium batteries is finally realized by controlling the on-off time of the Mosfet tube. Compared with the traditional extreme difference control method, the simulation results show that the two-level layered balancing control method proposed in this paper increases the rapidity of static and random currents by 23% and 17.1% respectively, and the accuracy increases by 13.3%. The proposed control approach can be provided with equalization efficiency highly, and give some advice for servicing lithium battery application.
The Challenges of Implementing the Indonesian Experimental Power Reactor (RDE) Program
Authors: Wisnubroto D S , Sunaryo G R , Susilo Y S B , Bahri S , Setiadipura T 
Published: October 2021

Abstract
This paper shows the effort to implement the RDE and its challenges from 2013 to 2018. RDE was a program to introduce nuclear power plants by building non-commercial power reactors. The RDE program was also used to prove that Indonesian engineers can design a reactor that will later supply electricity and steam for industry. The technology used is a high-temperature gas-cooled reactor. This RDE program is a very strategic intermediate target for energy security and national sovereignty. The development of RDE-based nuclear power plants, in the long run, is expected to have implications for reducing reliance on fossil fuels, more self-sufficiency in energy supply increases national industrial capacity and competitiveness in the global economic order, as well as enhance energy and political diplomacy. Also, RDE can be a reference installation for PeLUIt (Power and Steam Generators for Industry) power plants for small and medium enterprises to meet the demand for electricity and industrial heat in an area’s needs. However, many challenges occurred to implement this program; among them were cost estimation and cost-benefit analysis. Although the program has not been realized, mainly for financial reasons, many positive things have been obtained from these activities.
Uranium Exploration, Deposit and Resources: The Key of Nuclear Power Plant Development Program in Indonesia
Authors: Syaeful H , Sukadana I G , Susilo Y S B , Indrastomo F D , Muhammad A G , Ngadenin  
Published: October 2021

Abstract
Uranium deposit in Indonesia was found in almost all Indonesian Archipelago, mainly in Kalimantan, Sulawesi, Sumatera, Papua, Bangka Belitung and Riau islands. Uranium exploration activities started in the 1960s to recent, conducted in many exploration stages. The exploration in prospects area are completed with drilling activities to delineate the mineralization zone and continued to resources estimation. In Kalan Area, the research had been completed with underground/tunneling mining. The uranium resources are classified into discovered or undiscovered based on exploration stages, and conventional or unconventional based on sources of primary/secondary/by-product mineral production. The resources are calculated from Kalan Area and its surroundings (Kalimantan) with addition of Mamuju Area (West Sulawesi) and Sibolga Area (North Sumatera). Uranium identified resource in Indonesia is 13,503 tU while the undiscovered is 62,330 tU. Meanwhile, categorized by uranium source, the conventional and unconventional resources are 48,388 tU and 27,445 tU respectively. The uranium resources categories should be increased and completed with feasibility study to increase the resources to reserve classification. The exploration, deposit, and resources are the key to ensure the readiness of developing nuclear power plants in Indonesia, where one of them is Experimental Power Reactor (EPR) or Reaktor Daya Eksperimental (RDE) with domestic uranium fuel.