bluuebunny/crossref_metadata_2025 huggingface dataset:
Tunability of photonic crystals on stimuli-responsive liquid crystal polymer substrates: Mechanism, programming, and optimization
Authors: Zhang Yiqing , Huo Yongzhong
Published: February 2021

Photonic crystals (PCs) are nano-scale, dielectric structures with periodically varying refractive index and unique light propagation properties. Recently, PCs with tunable structural and optical characteristics under external stimuli have garnered extensive attention due to their potential application in smart optical devices. Liquid crystal polymers (LCPs) can generate recoverable deformation upon exposure to external stimuli. Recent experimental studies have demonstrated the tunability of PC films on LCP substrates under thermo- and/or photo-stimuli, which was primarily attributed to the bending of the bilayers. Furthermore, based on Timoshenko's classical bimetallic model, the reflective band shift has been assumed to be proportional to the bending curvature. In this study, based on some analytical solutions that extend the classical model, we demonstrate that the band shifts are proportional to the upper-surface transversal strain that is closely connected but generally not proportional to the bending curvature of the PC/LCP bilayer. Furthermore, it is found that the incorporation of spontaneous bending in addition to spontaneous contractions in the LCP substrates can be extremely helpful for the tunability of PC. This can be achieved either by programming the liquid crystal alignment or/and by light attenuation. The optimized bilayer structures exhibit immense potential to generate large reflective band shifts, especially for relatively softer PC films on stiffer LCP substrates. Overall, our results provide useful insights on the design of tunable PCs and other stimuli-responsive bilayer structures.
The impact of non-pharmaceutical interventions on the prevention and control of COVID-19 in New York City
Authors: Yang Jiannan , Zhang Qingpeng , Cao Zhidong , Gao Jianxi , Pfeiffer Dirk , Zhong Lu , Zeng Daniel Dajun
Published: February 2021

The emergence of coronavirus disease 2019 (COVID-19) has infected more than 62 million people worldwide. Control responses varied across countries with different outcomes in terms of epidemic size and social disruption. This study presents an age-specific susceptible-exposed-infected-recovery-death model that considers the unique characteristics of COVID-19 to examine the effectiveness of various non-pharmaceutical interventions (NPIs) in New York City (NYC). Numerical experiments from our model show that the control policies implemented in NYC reduced the number of infections by 72% [interquartile range (IQR) 53–95] and the number of deceased cases by 76% (IQR 58–96) by the end of 2020. Among all the NPIs, social distancing for the entire population and protection for the elderly in public facilities is the most effective control measure in reducing severe infections and deceased cases. School closure policy may not work as effectively as one might expect in terms of reducing the number of deceased cases. Our simulation results provide novel insights into the city-specific implementation of NPIs with minimal social disruption considering the locations and population characteristics.
Defect-mediated ab initio thermodynamics of metastable γ-MoN(001)
Authors: Lee Giyeok , Lee Hojun , Lee Taehun , Soon Aloysius
Published: February 2021

Refractory transition metal nitrides exhibit a plethora of polymorphic expressions and chemical stoichiometries. To afford a better understanding of how defects may play a role in the structural and thermodynamics of these nitrides, using density-functional theory calculations, we investigate the influence of point and pair defects in bulk metastable γ-MoN and its (001) surface. We report favorable formation of Schottky defect pairs of neighboring Mo and N vacancies in bulk γ-MoN and apply this as a defect-mediated energy correction term to the surface energy of γ-MoN(001) within the ab initio atomistic thermodynamics approach. We also inspect the structural distortions in both bulk and surfaces of γ-MoN by using the partial radial distribution function, g(r), of Mo–N bond lengths. Large atomic displacements are found in both cases, leading to a broad spread of Mo–N bond length values when compared to their idealized bulk values. We propose that these structural and thermodynamic analyses may provide some insight into a better understanding of metastable materials and their surfaces.
GaN-based fast, high output magnetic field pulser
Authors: Theh W. S. , Gaunkar N. Prabhu , Mina M.
Published: February 2021

Magnetic field pulsers (MFP) generate a pulsed magnetic field by driving current through an inductor. These pulsers have numerous applications based on the output magnetic flux density and switching time. This investigation will explore the application of gallium nitride-based (GaN) transistor in a MFP design. Based on the advantages of GaN transistors, the investigation looks towards creating a pulser capable of producing magnetic flux density of 500 Gauss with a rise/fall time of less than 500 nanoseconds. This investigation will improve upon findings from prior pulsers designed for magneto-optic switching applications. Simulation results have shown that for a given maximum current level, the GaN transistor pulser displays steeper rise and fall time when compared to a pulser employing a Si transistor. This result further highlights the potential of GaN transistor as the switching device where rapid field switching is preferable.
Preliminary modelling as the first stage of targeted organic synthesis
Authors: Titov Ilya Yu. , Stroylov Viktor S. , Rusina PolinaV. , Svitanko Igor V.
Published: February 2021

The review aims to present a classification and applicability analysis of methods for preliminary molecular modelling for targeted organic, catalytic and biocatalytic synthesis. The following three main approaches are considered as a primary classification of the methods: modelling of the target – ligand coordination without structural information on both the target and the resulting complex; calculations based on experimentally obtained structural information about the target; and dynamic simulation of the target – ligand complex and the reaction mechanism with calculation of the free energy of the reaction. The review is meant for synthetic chemists to be used as a guide for building an algorithm for preliminary modelling and synthesis of structures with specified properties.

The bibliography includes 353 references.
Critical role of Aquaporin-1 and telocytes in infantile hemangioma response to propranolol beta blockade
Authors: Moisan François , Oucherif Sandra , Kaulanjan-Checkmodine Priscilla , Prey Sorilla , Rousseau Benoît , Bonneu Marc , Claverol Stéphane , Gontier Etienne , Lacomme Sabrina , Dousset Lea , Couffinhal Thierry , Toutain Jerome , Loot Maya , Cario-André Muriel , Jullié Marie-Laure , Léauté-Labrèze Christine , Taieb Alain , Rezvani Hamid Reza
Published: February 2021

Significance

Although a role for β-adrenergic receptor (ADRB) in cancer progression was suggested a long time ago, our serendipitous observation of the propranolol efficacy in treating infantile hemangioma (IH) has driven attention in exploring the antitumor properties of β-blockers. We identified Aquaporine-1 (AQP1) as a player in antitumor propranolol response and as a histological marker of IH vascular structures including telocytes, which are dendritic cells that form a distinctive peripheral layer in IH. We conclude that IH sensitivity to propranolol may rely, at least in part, on a cross talk between lesional vascular cells and stromal telocytes.
Basal forebrain mediates prosocial behavior via disinhibition of midbrain dopamine neurons
Authors: Wang Jun , Li Jie , Yang Qian , Xie Ya-Kai , Wen Ya-Lan , Xu Zhen-Zhong , Li Yulong , Xu Tianle , Wu Zhi-Ying , Duan Shumin , Xu Han
Published: February 2021

Significance

The basal forebrain (BF) is traditionally recognized as a brain structure crucial for arousal, attention, learning, and memory. Here, we discovered a causal role of the BF in the control of prosocial behavior, which is fundamental for our daily life. We showed in mice that the BF somatostatin-expressing inhibitory neurons predominantly target GABA neurons and disinhibit dopamine neurons in the ventral tegmental area and thereby increase dopamine release in the nucleus accumbens. This disinhibitory circuitry played an essential role in promoting social interaction behavior. Our findings identify a previously unknown function of the BF in social behavior regulation and suggest a potential therapeutic target for social deficits commonly observed in major neuropsychiatric disorders.
Underwater acoustic multiplexing communication by pentamode metasurface
Authors: Sun Zhaoyong , Shi Yu , Sun Xuecong , Jia Han , Jin Zhongkun , Deng Ke , Yang Jun
Published: February 2021

As the dominant information carrier in water, the acoustic wave is widely used for underwater detection, communication and imaging. Even though underwater acoustic communication has been greatly improved in the past decades, it still suffers from slow transmission speeds and low information capacity. The recently developed acoustic orbital angular momentum (OAM) multiplexing communication promises a high efficiency, large capacity and fast transmission speed for acoustic communication. However, the current works on OAM multiplexing communication mainly appear in airborne acoustics. The application of acoustic OAM for underwater communication remains to be further explored and studied. In this paper, an impedance matching pentamode demultiplexing metasurface is designed to realize multiplexing and demultiplexing in underwater acoustic communication. The impedance matching of the metasurface ensures high transmission of the transmitted information. The information encoded into two different OAM beams as two independent channels is numerically demonstrated by realizing real-time picture transfer. The simulation shows the effectiveness of the system for underwater acoustic multiplexing communication. This work paves the way for experimental demonstration and practical application of OAM multiplexing for underwater acoustic communication.
An improved projector calibration method for structured-light 3D measurement systems
Authors: Yu Jing , Zhang Yaqin , Cai Zewei , Tang Qijian , Liu Xiaoli , Xi Jiangtao , Peng Xiang
Published: February 2021

In a structured-light three-dimensional measurement system, understanding the optical configuration of the projector and suppressing the eccentricity error caused by the camera perspective projection are critical to realize high-precision measurement. In this paper, we analyze the special offset optical structure in commercial projectors, where a larger diameter lens is used to ensure the quality of the projected image, and the position of the principal point has been shifted. Meanwhile, a projector calibration strategy that makes the camera’s optical axis perpendicular to the target plane is proposed to avoid the pollution of perspective projection distortion. The sub-pixel correspondence based on homography transformation is performed by relying on the phase value of the fringe, and bundle adjustment optimization is used to further improve the accuracy and robustness of projector calibration. The experimental results demonstrate that the proposed calibration method can improve the calibration accuracy by 52.52%.
High-performance ambipolar MoS2 transistor enabled by indium edge contacts
Authors: Le Thi Hai Yen , Khan Muhammad Atif , Venkatesan A , Watanabe Kenji , Taniguchi Takashi , Kim Gil-Ho
Published: February 2021

The integration of electrical contact into 2D heterostructure is an essential approach to high-quality electronic nano-devices, especially field-effect transistors. However, high contact resistance with transition metal dichalcogenides such as molybdenum disulphide (MoS2)-based devices has been a significant fabrication impediment to their potential applications. Here, we have demonstrated the advantage of 1D indium metal contact with fully encapsulated MoS2 within hexagonal boron nitride. The electrical measurements of the device exhibit ambipolar transport with an on/off ratio of

10

2

for holes and

10

7

for electrons. The device exhibits high field-effect mobility of

40.7

cm

2

V

−
1

s

−
1

at liquid nitrogen temperature. Furthermore, we have also analysed the charge-transport mechanism at the interface and have calculated the Schottky barrier height from the temperature-dependent measurement. These results are highly promising for the use of air-sensitive material heterostructure and large-scale design of trending flexible, transparent electronic wearable devices.
Algorithm for the choice of power supply system rational structure of gas pumping stations
Authors: Baburin S V , Turysheva A V , Kovalchuk M S
Published: February 2021

The article provides main unit and complex reliability indicators used to appreciate reliability of power supply systems for gas pumping stations. The main goals of reliability calculation are presented. The methodology for the determination rational structure of the power supply system is given. The algorithm for the choice of rational structure and its main stages are described. Recommendations for determination directions of optimization power supply system structure are given.
The methodology of choosing the distribution model of echoes for ground penetrating radar with broadband signals
Authors: Borisov S V , Vyboldin Yu K
Published: February 2021

The paper presents an approach to the solution of the problem of assessing the probabilistic characteristics of echo signals of ground penetration radar (GPR). This allows performing the synthesis of decisive statistical rules in the problems of detection and recognition of subsurface objects.
Modeling of hydrodynamic and kinematic processes during the operation of a mobile cargo rope complex
Authors: Lagerev A V , Tarichko V I , Lagerev I A
Published: February 2021

Cargo aerial ropeways are an efficient mode of transport in mining industry. The purpose of the paper is to develop a method for modeling kinematic and hydrodynamic processes in the mechanisms of movement of carrying-pulling ropes equipped with hydraulic drives with frequency-throttle control at all stages of work such as acceleration of the transported load, steady motion and braking. The options of sequential installation (one-way and two-way) of adjustable throttles relative to the hydraulic motor are considered. The developed mathematical model provides computer modeling in time of the main characteristics of the hydraulic drive - the pressures and volumetric flow rates of the fluid at the characteristic points of the hydraulic system, as well as the kinematic and power parameters of the movement of carrying-pulling ropes (traveled distance, linear velocity and acceleration, required power, surmounted operating loads). For a specific option of mobile rope complex, the calculations of the indicated hydrodynamic, kinematic and force parameters are carried out and the obtained results are analyzed.
Synthesis of the CNC machine control algorithms optimized with respect to the contour error using the genetic algorithm
Authors: Lyubich V K , Kurmashev A D , Frolov V Y
Published: February 2021

Traditionally control systems of CNC machines are built using the positional system structure, e.g. the uncoupled system (US) tuned on the symmetrical optimum. These systems have a relatively small contouring quality factor–the ratio of the contour speed to the contour error. To increase the quality factor of such systems, we proposed two new algorithms: the US tuned on the contour error optimum (US-C) and the neural coordinated control algorithm (NCCA). Both algorithms were tuned on a non-convex criterion using the genetic algorithm which allowed us to reduce the tuning time and acquire better optimal values of the criterion in comparison to the gradient descent method. The experiments were conducted using a mathematical model of a CNC machine based on real servo motors and lead screws. The results of the experiments showed that the usage of the proposed algorithms led to a significant increase in the quality factor, which has a positive effect on the overall productivity of the CNC machine. Furthermore, the NCCA use available resources better than the other tested algorithms which can be seen in the experiments with a lower initial contour error, a lower radius of the circle, and a higher contour speed. Besides, the US-C can maintain the contour speed better than other tested algorithms.
Nonlinear control of electric drive system of four-wheel mobile robot with two differential drive units
Authors: Meshkovskiy E O , Frolov V Ya , Kurmashev A D
Published: February 2021

This paper contains a solution to the problem of constructing an electric drive control system of a four-wheel mobile robot with two differential drive units. During the synthesis of this system, the asymmetry of the drive units’ location was taken into account. This makes it possible to take into account various robot designs. The finished system can be scaled to stabilize the contour movement of mobile robots with more than two rotary blocks. In conclusion, the results of numerical simulations of the control system for various configurations of the wheeled robot are demonstrated.
Blasthole jet drilling parameters evaluation by test rig
Authors: Musteykis A I , Levikhin A A , Anistratov K Y
Published: February 2021

The jet drilling method has significant advantages over mechanical ones. The article presents the results of the theoretical and experimental jet drilling apparatus for drilling blast holes in hard rocks granite and gneiss studies using the developed test rig. The main difference between the studied device and traditional thermal spallation drills is the low temperature of the working fluid. The specific energy consumption method was proposed to evaluate parameters of the jet drilling apparatus for various rocks types. It has been shown that minimal specific energy consumption for hard rocks is obtained with minimal chamber pressure sufficient for reaching certain Mach number at the nozzle exit. The developed test rig has experimentally shown a stable drilling process and, at the same time, a long durability of the apparatus.
Autonomous wheeled mobile robot maneuvering in constraint environment. Trajectory tracking quality criteria
Authors: Shabanov D V , Kozlovich A V , Valiev R R , Kochneva O V
Published: February 2021

In this article the problem of control system synthesis for differential drive wheeled mobile robots operating within constraint environment is considered. The proposed approaches of solving trajectory tracking problem take into account the geometric features of both the robot and the transported cargo. The collision avoidance problem is solved at the controller level, without any changes to the planned trajectory. Three approaches are proposed: minimizing the distance to the trajectory, minimizing the distance to the reference position, and maximizing the distance to obstacles. In these approaches the constant analysis of position of each point of robot’s body outline contour is used. Negative influence of the position of these points on qualitative trajectory pass is represented in vector form. For each of the approaches formalized tracking quality criteria are determined, methods of implementation of control systems and controllers taking into account these criteria are proposed. The part of the control signal responsible for taking into account geometry of the robot and avoiding collisions is defined via the force-moment vector representation. Results of simulation modeling prove the efficiency of the proposed approaches. A comparison of the proposed approaches is presented. Potential ways of more efficient use of these approaches are given.
Energy demand side management in stand-alone power supply system with renewable energy sources
Authors: Zhukovskiy Y L , Lavrik A Yu , Buldysko A D
Published: February 2021

The article presents the demand side management for electricity consumption in the conditions of autonomous power supply systems with several sources of generation–traditional and renewable energy sources. The paper gives a classification of household electrical appliances in accordance with this, even devices with a high priority, which are often referred to as non-shiftable load, can participate in the program. An algorithm for the interaction of the demand side management control system and the user is proposed. It is shown that with the participation in the demand management program even some types of equipment can achieve a significant economic effect, increase the service life of the equipment and reduce the negative impact on the environment.
Diagnostic assessment of base components of mining machinery of potash mines by analysis of excited vibrations
Authors: Shishlyannikov D I , Zverev V Yu , Zvonarev I E , Ivanov S L
Published: February 2021

The relevance of the wide use of diagnostic equipment to assess and predict the condition of mining machineries of potash mines is presented in this paper. A promising method of diagnosing the base components of mining machineries (load frames and integral body), which involves an analysis of excited vibrations, is described. The equipment for its implementation is presented. An example of assessing the condition of steelwork of the body of a self-propelled loader bunker BPS-25 is given in the paper. The implementation of an analyzer of the synchronous vibrations «Kamerton» manufactured by Scientific-Production Enterprise «ROS» LLC (Perm) is instrumental in determining the presence of structural changes in a body’s steel of a loader bunker and in confining the position of fatigue cracks. It is shown that the wear of the sides and body’s floor pan of the loader bunker is not uniform. The limiting values of the loss of metal on the sides and floor pan are determined. In this paper, the search for faults was carried out in the entire metal volume of the examined unit. The evidence that the use of «Kamerton» equipment allows reducing material and time costs for the assessment of the mechanical condition of the structural steelwork of mining machineries is presented.
Improving the reliability of determining physical properties of heterogeneous clay reservoir rocks using a set of techniques
Authors: Malyarenko A M , Bogdan V A , Blinov S A , Kotenev Yu A , Mukhametshin V Sh , Kotenev M Yu
Published: February 2021

Oil-water-saturated formations of Western Siberian fields represented by polymictic sandstones are often characterized by strong granulometric heterogeneity. This is the reason for an incorrect assessment of the physicochemical properties of reservoirs, including wettability. On the example of the BS9 - BS11 formations of two fields of Surgut oil and gas region, the distribution of wettability of core samples was analyzed. An analysis of the modeling results for the hydrocarbon phase displacement by oil-saturated reservoir water was carried out using the Tulbovich method. To assess reliability of the wettability values, it was proposed to correlate the difference in the masses of water and kerosene displaced during capillary impregnation and centrifugation with differences in the mass of water and kerosene in water-and kerosene-saturated samples. The method was used to plot the distribution of porosity, permeability and relative clay content on the wettability parameter by capillary impregnation and centrifugal displacement. The results obtained were compared with similar dependences of the reservoir properties and clay content on the general wettability parameter. The type of wettability of core samples with good reservoir properties is validated in complex, low-permeability reservoirs with a high content of clay material. It is recommended to use the results of modeling the displacement by capillary impregnation and centrifugation with differences in the mass of water and kerosene.
Characteristics of Prospective Student Teacher’s Representation in Solving Ill-Well Algebraic Problems
Authors: Santia Ika , Purwanto  , Subanji  , Sudirman  , Sutawidjadja Akbar
Published: February 2021

Mathematical representation is an important aspect of mathematical problem-solving. But prospective student teachers’ ability of a mathematical representation in ill-structured problem solving is still very limited compared to that in well-structured problem-solving. However, ill-structured problems supported mathematical abstraction used in mathematical concept understanding. This study described the characteristics of prospective student teachers’ representations and translation among representation in ill-structured and well-structured social algebraic problem-solving. Thirty Indonesian prospective students teachers have to solve the ill-well algebraic problems by using think-aloud while recorded using a video recorder and the researchers observed by writing on a field note to record the important events. Data were analyzed using a comparative method so that it was obtained the different characteristics of representations between solving ill-structured and well-structured problems. The result showed that verbal and symbolic representations used by subjects to compute, detect and correct an error, and justify their answers in ill-structured problem solving but visual representation only used by the first subject to detect and correct error. The subjects lack to uncover necessary information to solve the ill-Structured problem compared to that of a well-structured problem. It means that representation is important to be studied further because it affected to ill-structured problem ability.
Needs Assessment QR Code Combination with Google Form for Online Cognitive Assessment
Authors: Firmansyah Guntur , Dwi Rahayu Ervin , Hariyanto Didik , Irwansyah  , Setyawan Trinovandhi , Muhamad Aris Tria
Published: February 2021

This study aims 1) to develop online cognitive assessment instruments that meet instrument criteria such as validity, reliability, level of difficulty, different power, 2) develop online cognitive assessment instrument using a combination of qr code and Google forms. The research method refers to the Borg and gall R&D research method. The research subjects were students who were taking theoretical and practice courses on table tennis physical education and recreation education program IKIP Budi Utomo Malang Class of 2017. The results of the initial research of the needs analysis phase given to students and lecturers were 1) cognitive assessment instruments used were still have not met the eligibility criteria, 2) online media has not been used to conduct cognitive assessments, 3) students and lecturers agree if an online cognitive assessment instrument is developed in accordance with the instrument eligibility criteria and the media used a combination of qr code with Google forms.
Dialogic-Interactive Media Design for Language Learning To Improve Speaking Activities and Skills
Authors: Atmazaki  , Ramadhan Syahrul , Indriyani Vivi , Nabila Jeihan
Published: February 2021

Abstract.Technology is an unavoidable resource in the education sector, Technology can facilitate learning offline or online. Technology can be used for language learning. Therefore, the purpose of this study is to produce dialogic-interactive media used in Indonesian language learning to improve student learning activities and outcomes. This type of research is development research using Plomp Model (1997) which consists of three phases, namely (1) preliminary research phase; (2) prototype phase; and (3) assessment phase. The study was conducted to develop a product that is dialogic-interactive media to improve learning activities and speaking skills of secondary students in learning Indonesian. Based on the research stages, this article will explain the results of research in the design phase. The data analysis technique used in this study is a descriptive data analysis technique that describes the validity of the learning model. The research instrument was a questionnaire. Based on the results of the questionnaire analysis, it was concluded that the syntax for the development of dialogic-interactive media was categorized as very valid and could be used as a model for the development of instructional media that would be tested in schools.
Learning Management System and EFL Classes: A Way to Promote Autonomous Blended Learning
Authors: Fitrawati
Published: February 2021

This article aims to point out the advantages of using the Learning Management System to increase EFL learner skills and introduce it as one of the aid to support autonomous blended learning. This article also explains how LMS supports e-learning in learning language. Then, it shows how the e-learning can be implemented with using some models in teaching and learning process.
Incorporating both Zoom and YouTube in Micro Teaching Class during the Covid-19 Pandemic: An Effectiveness Investigation
Authors: Roza Veni
Published: February 2021

The article aims at seeking the effectiveness of incorporating both Zoom and YouTube in Micro teaching class by webinar. This class at the first was conducted traditionally by face-to-face interaction in the classroom. After that the Covid-19 pandemic came, all systems were shocked and changed. Students and lecturers had to keep distance socially and physically by learning and working at home. So, all Micro teaching classes were carried out on line by using internet aid using applications such as Zoom and YouTube. The research used quantitative method by distributing questionnaire to students and lecturers after they used the applications during the teaching learning process. Students’ scores in teaching performance were also considered to seek the effectiveness. The sample was selected purposively since not all lecturers applied webinar in their classes. The finding reveals that incorporating both zoom as a synchronous learning model and YouTube as an asynchronous one is effective in teaching micro teaching based on the lecturers’ responses in the questionnaires and viewed from students’ score in final teaching performance which was shared via YouTube in the middle of pandemic era.
Blending Technology with Post Method Pedagogy for Teaching Learning Process
Authors: Depalina Siregar Syamsiah , Lubis Mukhlis , Kohar  , Daud Batubara M. , Asrin Ahmad
Published: February 2021

Pandemic era bring new paradigm in teaching learning process. The lecturers must work hard to create new model, new strategies, and new ways in transmitting their information to the students. This study appears blending technology with post method pedagogy, where the learning process focuses on students need. There are three principles of post method pedagogy, they are particularity, practically, possibility. The lecturers blend conventional interaction with learning based technology. It blends based on students’ need and the target of the material itself. Post method pedagogy gives us challenges to create approptiate method for our class. Lecturers should help the students to success the learning process. The lecturers can used post method pedagogy in main part. In appling three parameters; particularly, possibility and practicallity based on students need.
The Strategic Development for Research Excellence in Thailand 4.0 of Postgraduate students Under Council of the Graduate Studies Administrations of Thailand (CGAT)
Authors: Raob Ismail , Abdullah Hasan Farid , Jeha Zakee
Published: February 2021

This paper aimed to investigate the exploratory factor analysis of research excellence in Thailand 4.0 and to develop the research strategy towards research excellence in Thailand 4.0 of postgraduate students under council of the graduate studies administrations in southernmost Thailand. The mixed method research design was applied in this study. The quantitative was initiated with exploratory factor analysis, and qualitative was used by focus group to develop the research strategy towards research excellence in Thailand 4.0. The Sample size in this study were 530 students. This paper followed factor analysis methods to set the sample. Sample size data was subject to item ratio1:10, 35 items that mean the sample were 530. Furthermore, the sample of qualitative research were 25 students. Besides, a questionnaire with five points rating scale was used to collect the data needed. For qualitative Focus Group the SWOT Analysis, Position Matrix, and TOWS matrix were used. Additionally, frequencies and exploratory factor analysis were used in the study. The data was analyzed using program R version 3.6.2. The finding found that the factor analysis for this measure yielded a seven factors solution with eigenvalues greater than 1.0. These factors were named as 1) research skill, 2) innovative thinking skill, 3) learning style skill, 4) commination skill, 5) digital skill, 6) academic writing skill, and 7) social and life skill. Furthermore, the SWOT analysis has been assessed through an analysis of strengths, weaknesses, opportunities and threats. All data will be analyzed in a matrix relationship using a table called TOWS Matrix. The TOWS Matrix is an analytical table that takes the data obtained from the analysis of SWOT to be analyzed to determine. Come out into the following types of strategies.
Developing Learning Model Based on the PMR Approach to Improve Student’s Knowledge in Mathemathics Learning
Authors: Azizah Nur , Fauzan Ahmad , Lufri  , Arnawa Made
Published: February 2021

There are several factors that cause the low achievement of students’ mathematics learning outcomes in several high schools in the Dharmasraya district, including: learning process plans (RPP), monotonous methods, only 15% of students who like mathematics, abstract material, lack of media, teacher’s difficulty in analogizing material into life around students or vice versa. This is a Research and Development that uses the Plomp development model, which consists of three phase the Preliminary, Prototype, and Assessment. Based on the results of this research that the learning design topic Implementation of sequences and series based on PMR approach has; The average value of HLT validity is 4.11 with a very valid category. The practical test of learning books applying PMR-based sequences and series by teachers and students is 85.02 and is classified as very practical. The average value of students’ mathematical reasoning ability tests after being tested is 76.97% and can be categorized as effective and it also can improve student’s knowledge in mathematics learning.
Computer Self Efficacy, The Availability of Information Technology Facilities, And Accounting Student Attitude
Authors: Hermawan Sigit , Biduri Sarwenda , Wahyu Ningdiyah Endra , Puspitasari Ratna
Published: February 2021

This study aims to analyze the influence of the availability of information technology facilities, experience, and attitudes of accounting students in using computers to computer self-efficacy (CSE). The analytical tool used is lists the questionnaire lists the SPSS 16.0, data collection in the form of test validity and reliability testing. The hypothesis of this study is that there is the influence of the availability of information technology facilities, experience, and attitudes of accounting students in using computers to computer self-efficacy (CSE). To test this hypothesis used data analysis tools such as multiple linear regression. The results showed that the availability of information technology facilities influence on computer self-efficacy (CSE), the experience effect on computer self-efficacy (CSE), and the attitudes of students in using computer effect on computer self-efficacy (CSE) and the availability of information technology facilities, experience, and attitudes affect students in using computers simultaneously on computer self-efficacy (CSE).
Integration of Distance Learning Design and e-Learning in Madrasah
Authors: Munif Muhammad , Umiarso  , Mardia  , Laili Nurul , Sa’dia Halimatus , Muhid
Published: February 2021

This study aims to determine the results of distance learning using e-learning, which is reviewed from a management perspective. This research uses a qualitative case study approach, with a research site at the Madrasah Aliyah Lubbul Labib Maron, Probolinggo, East Java, Indonesia. The results showed that; management of distance learning is carried out in several stages, namely; planning that includes learner analysis, determination of material, methods, approaches, media and evaluation techniques that will be used in learning activities. Furthermore, the results of the planning are implemented in online learning and evaluated according to what has been planned.
Zonal instability and wave trapping
Authors: Garbet X. , Panico O. , Varennes R. , Gillot C. , Dif-Pradalier G. , Sarazin Y. , Bourne E. , Grandgirard V. , Ghendrih P. , Zarzoso D. , Vermare L.
Published: February 2021

This paper presents a model for zonal flow generation based on a wave kinetic equation coupled to a poloidal momentum equation in a regime where wave trapping matters. Several models of the wave collision operator have been tested: Krook, diffusion and diffusion plus an instability growth rate. Conditions for zonal instability have been identified. It is found that a zonal instability is possible in all cases. However the force is a power law of the zonal velocity, so different from the quasi-linear case of random phases that produces a force that is linear in velocity. Also the zonal force may change sign, leading to flow radial profiles that are not sinusoidal.
Analytical method in the study of kinematics of process machinery mechanisms
Authors: Orlov B N , Karapetyan M A , Matveev A S
Published: February 2021

Among all technological machines and equipment, the object of the study was a drainage machine. The machine operates in particularly difficult conditions. The quality of operation depends on the maintenance of process parameters. The kinematics of a working element of the drainage machine and its suspension on the base machine significantly affect the accuracy of holding the given slope of a drain trench and slot. In recent years this issue has received considerable attention. However, the existing analytical methods for kinematic studies of drainage machine mechanisms are complex and therefore not always acceptable. The geometrical methods are used more often. The developed analytical method based on the use of complex numbers conveniently combines the analytical study of the kinematics of mechanisms with geometrical representation.
Modeling of contact interactions in lathe turning with accounts for rheology in the cutting zone
Authors: Vasilkov D V , Cherdakova V S , Bundur M S
Published: February 2021

This article discusses the dynamic modeling of contact interactions in the technological system of machining in the turning process based on piecewise linear approximation. A feature of the model is that it differentiates between the conditions of contact interaction between the front surface of the tool and the coming off chips, as well as between the back surface of the tool and the workpiece being processed. The consideration is based on the two-term characteristic of friction, realized in the form of a sequence of sliding and adhesion phases. In this case, the process of contact interaction in each phase is described by a set of rheological models. The phase switching conditions are determined by the rate of relative contact interactions, as well as the contact pressures between the front surface of the tool and the chips, between the back surface of the tool and the workpiece. Differentiated description of contact interactions from the front and back surfaces of the tool made it possible to build a tool for studying the processes of self-regulation of contact interactions in dynamic contours and the connectivity between them, which allows us to determine the conditions for the formation of self-oscillations that the dynamic system imposes on itself. The performed experimental studies have shown the correspondence between the nature of the movements during modeling and real cutting.
Influence of artificial filler made of calcium hydrosilicates of various basicity on the performance characteristics of non-autoclave hardened silicate materials
Authors: Volodchenko A A
Published: February 2021

The work established the nature of the effect of an artificial filler made of calcium hydrosilicates of various basicity on the physical and mechanical properties of non-autoclave silicate composites based on unconventional aluminosilicate raw materials, represented by clay rocks of an unfinished stage of mineral formation. It is determined that the optimal content of an artificial filler of the composition CaO:SiO2 is 1:1 in the raw mixture is in the range of 1–3 wt.%. The available interval makes it possible to vary the composition of the initial mixture and obtain products with the required properties, which is especially important when the material composition of the feedstock fluctuates, as well as in case of violation of the production technology. The rational content of the artificial filler of the composition CaO:SiO2 = 2:1 is 1 wt. %. It is shown that the addition of an artificial filler promotes the formation of a cementitious substance from neoplasms of a higher degree of crystallization, which contributes to an increase in the strength and water resistance of the material. Mathematical models are proposed for the selection and optimization of the compositions of non-autoclave silicate materials based on unconventional aluminosilicate raw materials and modified with an artificial filler represented by calcium hydrosilicates of various basicity to obtain materials with a compressive strength of 18-23 MPa with an average density of finished products of 1750-2000 kg/m3.
Theoretical and practical aspects of absorbing layers insulation in the conditions of hydraulically perfect modes of grouting solutions injection
Authors: Averyanov A P , Andreev V E , Chizhov A P , Mukhametshin V Sh , Chibisov A V
Published: February 2021

The article presents the results of theoretical and experimental studies of insulation of absorbing intervals during penetration of rocks. The proposed systematic approach makes it possible to effectively apply insulation methods in various mining conditions of well construction. The methods for controlling the absorption of drilling fluids in the conditions of abnormally low layer pressures are combined in a systematic technology.
Development regulation of oil and gas reservoirs based on effective geological and geophysical information
Authors: Batalov D A , Andreev V E , Mukhametshin V V , Kuleshova L S
Published: February 2021

The paper studies the dynamics of fracture reservoir management during the solution of the problems of the increase in the efficiency of development of oil deposits with hard-to-recover reserves. The directions of the creation of models of multichannel telemetry systems are studied from the point of view of the proposed concepts, as well as the conditions under which the study of well conditions is carried out. The results show that these telemetry systems can function in a well when the sensor elements are integrated, which are based on a single-core armored cable.
Modeling of clay acid effects on the bottomhole zone of wells
Authors: Safiullina A R , Mukhametshin V V , Kuleshova L S , Batalov D A
Published: February 2021

Typical wells have been identified in the conditions of the Langepass group deposits, according to which modeling of the clay-acid process on the bottom-hole formation zone has been performed. There was a significant increase in the efficiency of operations based on the use of developed models, which allows choosing the most optimal technologies and exposure parameters depending on the properties of the productive formations.
Geological and technological justification of the parameters of acid-clay treatment of wells
Authors: Gabzalilova A Kh , Batalov D A , Mukhametshin V Sh , Andreev V E
Published: February 2021

The article shows that modelling and design definition of the impact requires the differentiation for a specific well-formation system. The authors found that the effective use of acid-clay exposure in terrigenous strata is possible in various geological and technological conditions considering the criteria for the impact applicability and the implementation of a specific impact design. They proposed to use selective acidic solutions of selective action to increase the efficiency of secondary acid treatments.
Oil and gas well drilling technology based on the system approaches and the results of application
Authors: Gazizov R R , Chizhov A P , Andreev V E , Chibisov A V , Mukhametshin V V , Kuleshova L S
Published: February 2021

The article analyzes the reason and factors of declining in key indicators of quality and efficiency of well construction and operation, which have led to a long-term stagnation in drilling technology. To handle the urgent issues, a systematic approach to implement the complex of hydro-mechanical hardening of an open-hole well by the synchronous and coordinated action of hydraulic monitoring strings of drilling fluids is proposed. The indicators of quality and efficiency of the complex compared to the traditional ones, which exceed the former by two or more times, are provided.
Improving the efficiency of horizontal wells at multilayer facilities
Authors: Khuzin R R , Mukhametshin V Sh , Salikhov D A , Andreev V E , Pepelyaev D V , Stefanovich Yu N
Published: February 2021

The paper presents the results of testing of new production equipment of wells, as well as the operating modes of horizontal wells in the conditions of development of multilayer facilities. The paper also presents the results of drilling small-diameter wells, the methods of oil production intensification, and the principles of operation of pumping equipment with an electric valve with account for optimal draw-downs on reservoirs. The suggested approach to the operation of horizontal, sub-horizontal and directional wells of small diameter allows increasing the technical and economic indicators of the development of complex multilayer facilities. It is proposed to use the developed technology in the operation of two or more reservoirs in conjunction with the implementation of dual injection into the exploited reservoirs through injection wells in the center of the element of development.
Microwave separation of persistent oil emulsions
Authors: Nafikova R A , Soloviev N N , Mingulov Sh G , Safiullina A R
Published: February 2021

At present, the development of more effective methods for preparing such oils requires special attention due to the growing share of hard-to-extract high-viscous hydrocarbon reserves. The study examined the effectiveness of the thermochemical method and the method combining microwave radiation intended to separate high-viscous emulsions resulting from the thermal methods to increase oil recovery. The results of the research justify the need to use a complex impact aimed at separating persistent oil emulsions.
A mathematical model of a vibrator with an axial striker mechanism
Authors: Khuzina L B , Zaripova L M , Gabdrakhimov M S
Published: February 2021

To be operated effectively by the production and injection wells, the nature of oil reservoir production is largely determined. The efficient operation of wells depends on geological and technological factors. This refers to their exploitation with oil output equal to the potential capabilities of the reservoir when it is fully served by the filtration process. The bottom-hole zone (BHZ) is in a non-equilibrium thermodynamic state of energy and mass exchange with the well and the reservoir. The contamination of the bottom-hole zone has a significant impact on the effectiveness of wells.