bluuebunny/crossref_metadata_2025_split huggingface dataset:
An experimental investigation on the influence of temporary plugging fibers and particles on the fracture conductivity
Authors: Luo Yao , Han Shaobo , Kong Hui , Wang Rong , Dong Enjia , Cai Zhuolin , Zhou Fujian 
Published: March 2022

AbstractAfter temporary plugging and fracturing, some of the difficult-to-degrade temporary plugging agents (fibers and particles) in the fractures will affect the conductivity and ultimately affect the rate of oil production. However, the influence law and mechanism of the fibers and particles on the fracture conductivity are still unclear. In order to solve this problem, based on the FCS-842 fracture conductivity test system, the influence law and mechanism of fibers and particles on the fracture conductivity were investigated. The experimental results show that the larger particles support the fracture wall when particles are contained, resulting in higher conductivity. Further studies have found that high fibers content will lead to a significant decrease in the fracture conductivity under low closure pressure. However, high particles content means high fracture conductivity. The placement position of fibers and particles also affects the fracture conductivity. When the pressure is 10 MPa, the conductivity is maximum when the fibers and particles are placed at the fracture opening. Then, when the pressure increases, the conductivity drops sharply by about 88%. When the closure pressure is ≥ 20 MPa, the conductivity is the highest when the fibers and particles are placed at the fracture tip, followed by the middle of the fracture and the smallest at the fracture opening. After analysis, at the fracture opening, the high flow velocity forms a fiber “Barrier” in the fracture, which makes the conductivity decrease rapidly. In the middle of the fracture, the “Dot-net” structure composed of fibers and particles makes the fracture conductivity decrease, but the decrease amplitude and speed are small. At the fracture tip, the lower flow rate makes the fibers and particles form “Clusters”, and the large flow channel between the clusters makes the fracture conductivity higher than the former two. When the fibers and particles are evenly laid, the fibers are easy to form clusters with the particles to block the flow channel, reducing the fracture conductivity.
Experimental study on settlement law of multi-particle compound temporary plugging material in rough fracture
Authors: Lv Bei , Lang Hao , Luo Yao , Zhang Wei , Shi Peize , Wang Bo , Kong Hui , Hu Xiaodong 
Published: March 2022

Abstract
To study the migration and settlement law of temporary plugging particle in fractures, a set of fracture visualization device with controllable pumping rate was built. Based on the experimental device, the influence of the parameters such as pumping rate, particle size combination and adding sequence on the sedimentation and accumulation of temporary plugging particle was studied respectively. The experimental results show that the amount of particle deposition in the fracture is the largest when the pumping rate is 0.04 m3⋅min-1; Under different particle size combinations, 3 mm particles settle earlier than 1 mm particles and the volume of the accumulation is proportional to the proportion of 3 mm particles. The effect of the sequence of addition on the morphology of the particle accumulation is mainly reflected in the layering of the accumulation. When the 3 mm particles are added first and then the 1 mm particles are added, the accumulation volume is larger and the particles settle more. In summary, when a combination of 0.04 m3⋅min-1 rate and 3 mm: 1 mm=4:2 particle size is selected, and 3 mm is added first, and then 1 mm particles are added, the temporary plugging particle has a larger volume of sedimentation in the fracture.
Investigation on the influence mechanism of wall-fluid interaction on flow around nanoscale circular cylinder
Authors: Yao Shuting , Pan Yu , Wang Jiansheng , Liu Xueling 
Published: March 2022

Abstract
The influence of atomic interaction strength between solid wall and fluid on the flow around a nanoscale circular cylinder was numerically probed with the molecular dynamics method. The results show that when the flow velocity is 2.2 and Reynolds number is 23, vortices are periodically formed behind the circular cylinder at the nanoscale, and go through the development and shedding. With the weakening of wall-fluid interaction between cylinder surface and fluid atoms, the vortex shedding period decreases, the Strouhal number increases, the weak wall-fluid interaction is beneficial for increasing vortex shedding frequency. It reveals that the length of time-averaged vortex behind the nanoscale cylinder decreases slightly with the decrease of wall-fluid interaction. Furthermore, the fluid density and velocity are symmetrically distributed along the central axis of nanoscale cylinder. As the wall-fluid interaction decreases, the binding force of cylinder surface to the fluid atoms decreases, which results in the decrease of the minimum value of fluid density in the upper right and lower right regions near the cylinder. And, the argon fluid is more prone to occur velocity slip on the cylinder surface, the corresponding velocity near the cylinder surface increases significantly.
Fracturing scheme design for unconventional reservoirs based on geology-engineering integration method
Authors: Su Hang , Zhou Fujian , Zheng Ao , Dong Rencheng , He Bencheng , Wang Fei , Liu Hongtao , Li Junjian 
Published: March 2022

Abstract
Horizontal drilling and hydraulic fracturing can effectively increase the contact area between fractures and reservoir, which are important method to realize the economic and efficient development of unconventional reservoirs. In the traditional fracturing scheme design, “sweet spots” guide the fracturing construction. However, due to lack of the interaction process of using engineering data to validate and correct the original data until the final convergence with reality, it cannot be dynamically optimized and matched in time. To overcome above shortcomings, this paper proposes a new network fracturing scheme design workflow based on the integrated geological-engineering integration (GEI) method. The tight carbonate reservoir X layer of oil field A in the Middle East is set as a case. A comprehensive sweet spot evaluation method is established using the partial correlation coefficient analysis method, considering the physical properties and fracturing performance of reservoir. The comprehensive sweet spot model is calibrated and optimized using experimental data, stimulation parameters, well tests, and production data. Based on the comprehensive sweet spot model, the quadrant chart is plotted and varied single well fracturing scheme designs are implemented for different quadrant areas. The numerical simulation results show that it can improve the development efficiency of unconventional reservoirs.
Processing red mud as a factor of removing the risk of environmental disasters: RUSAL experience
Authors: Litovchenko V I , Shumakova N A 
Published: March 2022

Abstract
The paper considers the current problem of waste management of aluminum production in the Krasnoyarsk Territory. The negative consequences of the existence of sludge collectors of aluminum production for the natural environment and the population of the region are shown. The analysis of the consequences of environmental disasters, such as cancer in the population, chemical pollution of groundwater and surface water caused by leakage of hazardous substances, is presented. The experience of RUSAL, as well as international experience in the field of waste processing is presented.
Concentration dependences of the structural, magnetic and kinetic properties of manganese chalcogenides doped with tellurium
Authors: Romanova O B , Sitnikov M N , Loginov Yu Yu , Hichem Abdelbaki 
Published: March 2022

Abstract
The effect of anionic substitution on the structural, magnetic, and kinetic properties of chalcogenides of the MnSe1-XTeX system in the temperature range of 77-400K in magnetic fields up to 12 kOe was studied. With an increase in the substitution concentration, changes in the structural and magnetic characteristics, which correlate with changes in the electronic structure, were found. The type and mobility of the main current carriers were determined from the Hall effect measurements.
Applications of group theory in crystallography
Authors: Senashov V I 
Published: March 2022

Abstract
Group theory is a powerful tool for studying symmetric physical systems. Such systems include, in particular, molecules and crystals with symmetry. Group theory serves to explain the most important characteristics of atomic spectra. Group theory is also applied to the problems of atomic and nuclear physics. This paper gives examples of the use of the apparatus of group theory in research on crystallography, quantum mechanics, elementary particle physics. In particular, in these studies matrix groups and representations of unitary groups are actively used. For such groups we give an overview of the results on their recognition by the spectrum (by the orders of the elements of the group). This direction has been intensively developed in recent years both in our country and abroad. Recognition of finite simple non-Abelian groups by spectrum has been studied for last thirty years in Yekaterinburg at the Institute of Mathematics and Mechanics of the Ural Division of the Russian Academy of Sciences, in Chelyabinsk Federal University and in the Novosibirsk Institute of Mathematics of Siberian Division of the Russian Academy of Sciences. Some simple non-Abelian groups are not recognizable by their spectra. We have proposed an approach for recognizing groups by the bottom layer. The bottom layer of a group is the set of its elements of prime orders. A group is called recognizable by the bottom layer under additional conditions if it is uniquely restored by the bottom layer under these conditions. The paper considers some examples of simple non-Abelian finite groups that are not recognizable by spectra. For these examples, simultaneous recognition by spectrum and by the bottom layer is proved.
An intelligent voice recognition system based on fuzzy logic and the bag-of-words technique
Authors: Stefanenko O S , Lipinskiy L V , Polyakova A S , Khudonogova J A , Semenkin E S 
Published: March 2022

Abstract
This paper describes a method for recognizing voice command based on a fuzzy logic system capable of perceiving fuzzy commands, i.e. commands containing fuzzy terms, for example, ‘close’, ‘closer’, ‘close to’, ‘closer than’, ‘further’ and ‘very far’. The developed approach has the ability to be trained for a specific user. The developed fuzzy logic system is used to recognize linguistically inaccurate commands in order to increase the expressiveness of the language for control of a moving robot.
Multiprocessing implementation for MCNP using Python
Authors: Arif Sazali Muhammad , Syahir Sarkawi Muhammad , Syazwani Mohd Ali Nur 
Published: March 2022

Abstract
Monte Carlo N-Particle (MCNP) is a widely-used code in nuclear engineering, but it needs high computation times due to the tracking of every single particle and interaction event. This causes shielding optimization using trial-and-error to take long times to complete. It can be solved by using multiprocessing, but this requires the MCNP source code which can be difficult to obtain. Therefore, this paper aims to suggest a solution on how Python can be used to run multiple instances of the code in shielding optimization. Two hardware setups were tested: one with a dual-core CPU, and one with a six-core CPU. Each of them would run several repeated simulations with and without multiprocessing enabled. Comparisons were made between each case of the same setup to observe the improvements in completion time. A tutorial of the Python algorithm is also provided in the methodology.
Evaluation of scattering effects for radiation shielding or filter materials by using Monte Carlo simulation
Authors: Miza Osman Nur , Mohamad Tajudin Suffian , Hanim Aminordin Sabri Adila , Faddilah Mohd Noor Arif , Zahri Abdul Aziz Mohd 
Published: March 2022

Abstract
Most radiology departments utilize ordinary concrete and lead for radiation shielding as the primary radiation can be reduced through photon absorption. There are many studies done focusing on the transmitted photons that penetrate the shielding materials for radiation shielding. However, the scattering from the shielding materials would be ignored. When high-energy photons impinge on thick shields, most of the incident energy is absorbed in the shielding materials, but some of it can also be deflected sideways or in a backward direction. This is important as the backscatter radiation can contribute to unnecessary additional radiation dose to healthcare workers. Hence, this study evaluates several shielding materials namely aluminium, iron, copper, lead, ordinary concrete, and heavy concrete particularly for its attenuated and scattered photons for radiation shielding. The shielding materials were evaluated using the Monte Carlo simulation, specifically PHITS code. In the simulation, all shielding materials were modelled as a fixed 30 x 30 cm rectangular shape with a fixed thickness of 10 cm. Mono-energy and pencil beam photon energies ranging from 100 keV until 1 MeV were directed to the shielding materials. As a result, at 100 keV, lead shielding showed the least amount of transmitted dose compared to other shielding materials. However, lead shielding also showed the highest reflected dose at the same incident photon energy. As copper showed the least amount of reflected dose at this incident energy, hence applying a thin layer of this material to lead shielding can tolerate the compromise between low transmitted dose and high reflected dose. Therefore, this can improve the radiation shielding at various irradiation facilities. In conclusion, the reflected dose for all materials studied will increase or higher when the incident photon energy increase, except for lead as well as for low-Z element materials rather than high-Z element materials.
Superconducting properties of (Bi,Pb)2Sr2Ca2Cu3Ox (BSCCO-2223) superconductor ceramics prepared by conventional solid-state reaction and co-precipitation methods
Authors: Mohiju Zaahidah ‘Atiqah , Mujaini Madihah , Hamid Nasri A. 
Published: March 2022

Abstract
The (Bi,Pb)2Sr2Ca2Cu3Ox (BSCCO-2223) samples were prepared by conventional solid-state reaction and co-precipitation methods. The crystal size, cell parameter, and crystal structure were identified from X-ray diffraction (XRD). The peaks drawn by co-precipitation have higher intensities and the width of peaks were narrower compared to the sample prepared by solid-state method. Slight difference in the value of lattice parameters between the samples were also noticeable. Concentration of defects increased the distortion of crystal lattice that cause the changes in these parameters. The electrical properties of the superconductors were investigated by using cryogenic four-point probe and AC susceptibility. The sample prepared by co-precipitation method was able to reach higher critical temperature, TC at 106 K compared to the other sample, TC at 97 K. Meanwhile Scanning Electron Microscope (SEM) micrographs for solid-state method sample showed more random grain alignment and porous structures. The microstructures and grain growth results of Bi-2223 were reflected to the heat and temperature applied during sintering process. In short, the research work reveals that co-precipitation method produces better quality of high temperature superconductor compared with solid-state method due to higher homogeneity resulted by chemical reactions.
Polyethylene composite with boron and tungsten additives for mixed radiation shielding
Authors: Arif Sazali Muhammad , Khair Alang Md Rashid Nahrul , Hamzah Khaidzir , Mohamad Idris Faridah , Syahir Sarkawi Muhammad , Syazwani Mohd Ali Nur 
Published: March 2022

Abstract
Mixed neutron and gamma radiations are common in many nuclear applications. Several materials can be combined to obtain a composite material that is better for mixed radiation than the individual component materials. The aim of this paper is to investigate the shielding effectiveness of a polyethylene (PE)-based composite with boron and tungsten additives. Several compositions are tested to shield against a 252Cf fission neutron source using an attenuation experiment. The composite is also manufactured using the melt-mixing method of component raw materials. Comparisons are made between the different compositions and the experimental results. Results suggest that the PE composite with 16%wt boron and 16%wt tungsten show the best mixed radiation attenuation as compared to pure PE, PE composite with 25%wt boron, and PE composite with 25%wt tungsten.
The effect of various electrospinning parameter and sol-gel concentration on morphology of silica and titania nanofibers
Authors: Abdillah Umar , Yazid Hafizal , Ahmad Sahrim , Makhtar Nurulizzati , Zaubidah Siti , Shan Chen Ruey , Hadifah Syifa Nur 
Published: March 2022

AbstractNano scale fibers of SiO2and TiO2with various compositions of viscosity and parameter have been prepared by electrospinning the precursor of tetraethyl orthosilicate (TEOS) and titanium (IV) isopropoxide (TiP). Different concentrations of polymer precursor polyvinylpyrrolidone (PVP) and applied voltages were studied. Distance tip to collector of 15 cm and flow rate of 0.003 mL/h were fixed for entire electrospinning process. The morphology of nanofibers was evaluated versus different solution concentrations as well as different applied voltages. Concentration focused in this study included 5 %wt, 10 %wt and 15 %wt of PVP along with 15 kV – 17.5 kV of voltages applied. The as-spun nanofibers were characterized by SEM. Results showed that the average fiber diameter decreases with decreasing of polyvinylpyrrolidone (PVP) solution concentration.
Fabrication of magnetic sugarcane bagasse paper
Authors: Azlin Azmi Annur , Amira Othman Siti 
Published: March 2022

AbstractGenerally, development in the pulp and paper industry requires extensive cutting of trees, which in effect contributes to deforestation. The dramatic growth in demand for wood supply, combined with the increasingly increasing cost of timber, has created a surge of interest in the use of non-wood plant fibres for paper production in widely developed countries. The use of waste material in pulping and paper-based industries could be beneficial as it helps prevent the need for disposal, which currently increases agricultural costs and causes environmental deterioration due to pollution and fires. In this research, the sugarcane bagasse was dry and chopped into 5 cm in lengths. The fibre and pulp were separated and put in a pulp disintegrator then it was weighed and mixed with water. The paper that fabricates will be irradiated with gamma-ray and then followed by characterizing with Scanning Electron Microscope- Energy Dispersive X-Ray Analysis (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). The SEM-EDX result shows that the weight and atomic percentage of the ferrite (Fe) increase after the irradiation. While for the FTIR, the entire sample exhibit the absorption range of 3400 to 2400 cm−1region. The paper will be compared with the properties of multipurpose paper.
Applying empirical method for performance metrics measurement of a nuclear security system
Authors: Ibrahim Maizura , Nurbahyah Hamdan Siti , Ismail Saa’idi , Safuan Sulaiman Mohamad , Norazam Mohamed Aris Sufian , Hasnor Bin Hasan Mohd , Dzul Aiman Aslan Mohd , Fatini Abdul Ghani Nur , Hamijah Ab Hamid Amy 
Published: March 2022

Abstract
A nuclear security system is often developed based on a particular framework. In our case, a nuclear security system is developed based on the big data analytics framework with the purpose of integrating all nuclear security systems within a nuclear facility. Nuclear security can be defined as the prevention and detection of, and response to, theft, sabotage, unauthorized access, illegal transfer, or other malicious acts involving nuclear material, other radioactive substances, or their associated facilities. Whereas, big data analytics is denoted as a new way of collecting, analyzing large amounts of data, finding the appropriate patterns to support decision making, hence improving the action taken in solving the problems. The system-based evaluations methodology is widely used to measure the performance metrics of nuclear security systems. However, the system-based evaluation methodology consumes time and demands a lot of effort because in applying the methodology, a complete nuclear security system that is based on the particular framework needs to be designed, developed, and implemented in the nuclear facilities environment before the performance metrics could be measured. In this paper, we present an empirical method of measuring the performance metrics by utilizing the Rasch Measurement Model. The methodology is formulated to reduce the time and efforts in measuring the performance metrics of a nuclear system that is developed based on a framework…
Amorphous black phosphorus: wet-chemical synthesis and atomic disordering-dependent electrocatalytic performance
Authors: Sun Zhaojian , Zhang Bowen , Khurram Muhammad , Yan Qingfeng 
Published: March 2022

Abstract
Although crystalline black phosphorus (c-BP) is attracting enormous interest in the past few years for a wide range of applications, studies on amorphous BP (a-BP) have been quite rare due to the difficulty in its controllable synthesis. The reason lies in that the elemental phosphorous precursor favors to form c-BP, which is the thermodynamically stable phase. Herein, we report a facile ethylenediamine intercalation-and- deintercalation strategy to realize gram-scale preparation of a-BP. The atomic disordering in a-BP can be handily tuned by controlling the reaction time. Interestingly, the a-BP demonstrates atomic disordering-dependent oxygen evolution reaction (OER) activity. The a-BP with higher atomic disordering delivers higher OER performance. Such enhanced OER activity is ascribed to more low-coordination sites and unpaired electrons which usually served as active sites, as verified by electrochemically active surface area measurement results and electron spin resonance. Density functional theory calculation further reveals the enhancement for OER activity is mainly attributed to boosting conversion from O* to OOH*. Our results not only create a controllable wet-chemical approach to scalable production of a-BP but provide insights into structure-property relationship and its underlying mechanisms.
Refining and reinforcing effects of TiC-Al2O3/Al ribbons inoculant on Al–Si–Mg–Ti alloy
Authors: Liu Lu , Cui Chunxiang , Geng Hongtao , Liang Yingguang , Cui Sen , Lei Shichang , Zhang Shuo 
Published: March 2022

Abstract
In this study, TiC-Al2O3/Al ribbons inoculant were prepared by mechanical alloying, spark plasma sintering (SPS) and melt spinning. Adding 5vol.% TiC-Al2O3/Al ribbons to an Al–Si–Mg–Ti (ASMT) alloy melt significantly refined the α-Al grains from 28.5 μm to 14.9 μm. In addition, the morphology of the eutectic silicon were modified and optimized, changing from needle-like silicon to spherical silicon. Adding the TiC-Al2O3/Al ribbons significantly improved the mechanical properties of TiC-Al2O3/Al–Si–Mg–Ti (TAASMT) alloy, including its elastic modulus (EM), yield strength (YS), ultimate tensile strength (UTS) hardness, and elongation which were increased by 5.4%, 18.4%, 32.7%, 8.3%, and 62.3%, respectively. These increases in the mechanical properties could be attributed to the intracrystalline reinforcement of the Al2O3 and TiC nanoparticles, well-bonded particle/matrix interface, modification of the eutectic silicon phases, and synergistic effects of the Orowan strengthening, Coefficient of thermal expansion (CTE) mismatch strengthening, load transfer, grain refining strengthening, and geometrically necessary dislocations (GND) strengthening.