bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recurrence of earthquakes in the area of the Toktogul HPP cascade
Authors: Ts Manzhikov B 
Published: December 2021

Abstract
A brief statistical analysis of the current seismicity of the Toktogul region of the Kyrgyz Republic is done. The analysis concerns the region where the Toktogul HPP cascade on the Naryn River is located, and covers the period from 1973 to 2021 years. The space-time distributions of earthquakes, accumulation characteristics, probability and recurrence of seismic events of various magnitudes are considered. According to the analysis results, the maximum magnitude of seismic events in the Toktogul region can be ∼ 7.4, and the recurrence period of earthquakes with a magnitude of M ≥ 7 and above T ≥ 10 years is equal.
Modified data on geoeffective solar flares and seismic noise variations
Authors: Sycheva N A , Bogomolov L M 
Published: December 2021

Abstract
The problem of the relationship between strong magnetic swarms caused by solar flares and variations in seismicity is considered. The data on the temporal dependences of the parameters of seismic noise (average level, and standard deviation, RMS) recorded by the stations of the KNET seismic network have been used as the output data of monitoring the territory of the Bishkek geodynamic proving ground (Northern Tien Shan). The signatures of the influence of a magnetic swarm that occurred after an ultra-strong solar flare on September 6, 2017 have been established. The results obtained on the increase in seismic noise after this super-strong eruptive event are consistent with the results of studies on the influence of magnetic swarms on changes in regional seismicity.
Application of the soft starter for the asynchronous motor of the belt conveyor
Authors: Dmitrieva V V , Sizin P E , Sobyanin A A 
Published: December 2021

Abstract
The purpose of the work is to justify the need for a smooth start of the conveyor belt. Based on the technological features of the transportation process, the direct start of the conveyor with a loaded undercarriage entails an increase in inertial forces, overload of the traction chains and the drive. Due to the increased starting torque, there is a danger of slipping, the occurrence of an oscillatory transient of the escaping branch of the tape, slipping between the tape and the drive drum. This leads to significant wear of the tape and breakdowns of other equipment, which requires high repair costs. With a smooth start of the conveyor, the acceleration lasts longer, but the movement of the concentrated masses of the belt is more consistent, less oscillatory, which indicates less dynamic forces in the belt. Also, with a smooth start, energy losses in the engine and its heating are reduced. The main results of the work - the transients in the currents of the stator and rotor, in the speed of rotation of the motor and in the speed of movement of the conveyor belt were obtained. The developed model allows us to investigate the dynamic operating modes of the engine and the mechanical part of the conveyor, to analyze the forces arising in the belt during direct and smooth start of the conveyor, to evaluate the slip of the belt and the magnitude of the traction factor. Conclusions - the results of this work should be the basis for controlling the tension in the belt and maintaining the traction factor of the conveyor belt in the start-brake operating modes. In addition, the results obtained can be used in the development of a belt speed control system depending on the amount of random freight traffic entering the conveyor.
Improvement of reagent flotation modes of sphalerite and pyrite from deposits of copper-zinc pyrite, polymetallic copper-zinc pyrite and polymetallic ores
Authors: Kyaw Z Y , Tiagalieva Z A , Htet Z O , Phyo K K 
Published: December 2021

AbstractCopper-zinc pyrite (Sulphide) and polymetallic ores of Russia are complex and difficult to process mineral raw materials. The main technology for the enrichment of this ores are flotation. Currently, the improvement of the flotation technology of this mineral raw materials is carried out in several way. It has been established by the practice of beneficiation of copper-zinc ores that obtaining high-quality zinc and pyrite concentrates is impossible without adding flotation modifiers of sphalerite and pyrite to various flotation operations. This reagent are copper (II) sulfates, zinc and iron (II) sulfates in an alkaline calcareous medium. Therefore, studies on the flotation of sphalerite and pyrite in an alkaline calcareous medium with the addition of one of these metal sulfates to the mineral flotation operation were performed. The effect of each copper (II) sulfates zinc, and iron (II) on the flotability of sphalerite and pyrite was studied during flotation of the mineral and xanthate and dithiophosphate at pH = 8, 10, and 12. The aim of this work was to study the effect of the flotation size class (- 0.074 + 0.044 mm) sphalerite and pyrite of one of the Russian deposits by sulfhydryl collectors in the presence of copper, zinc and iron sulfates in the liquid phase of flotation pulp
Dynamics of glass windows in mining vehicles under the impacts of rock pieces: numerical and analytical comparison for computational models validation
Authors: Sukhanova O , Larin O , Ziętek B 
Published: December 2021

Abstract
This study represents the results of linear dynamics analysis of glass plates subjected to rock pieces impacts occurring in underground machines’ windows. The aim of the work is to provide analytical and numerical solutions, obtain frequencies and plate displacement, and compare results of stress calculation for different models. The work performs finite element method (FEM) computations within a modal analysis in 3D statement including a mesh-size convergence analysis. Given approach is a basement for estimation of safety work conditions for operators in cabins of underground mining vehicles when glass windows are subjected to rock bursts and damages.
Employing the digital platform for control system development in a coal mining enterprise
Authors: Nepsha Fedor , Varnavskiy Kirill , Voronin Vyacheslav , Ermakov Alexandr , Kostomarov Roman 
Published: December 2021

Abstract
The article discusses the issues related with a digital platform for distributed energy resources in the framework of mining enterprises. The paper examines the directions of sustainable development of the infrastructure of a mining enterprise, among which it is necessary to highlight the use of digital twins, taking into account the relationship of technological processes with the processes of transport of electrical energy, the development of small generation and the use of renewable energy sources. The authors proposed a two-level architecture of a coal mine control system, the implementation of which is possible with the introduction of IoT devices. It includes the EDGE layer and the Cloud / on-premise layer, which implement the corresponding functions. In the future, such a control system will make it possible to implement the concept of unmanned mining with the effective use of machine learning methods. In conclusion, it was noted that it is important to ensure the synergy of the developed platform solutions in the electric power industry and the mining industry to reduce the total costs of creating digital mining enterprises and step-by-step implementation of the Industry 4.0 concept.
Detection of a predefined acoustic pattern by a measurement system on a drone and its application to search for a missing man in an underground mine
Authors: Zimroz Paweł , Wróblewski Adam , Trybała Paweł 
Published: December 2021

Abstract
Due to the very difficult working conditions and a certain number of hazards that do not occur in other industries, the operation of rescue units in underground mines is necessary. The area of exploitation is usually very large, thus determining the location of a person, which may be in need due to the accident, is not an easy task. As the time for reaching such a person is crucial, there is a strong need for a solution that would provide a quick establishment of the victims’ location. Moreover, conducting a rescue mission is always associated with risk exposure for rescuers’ life and health. Thus, in this paper, we propose a solution based on an unmanned aerial vehicle (UAV) for a predefined acoustic pattern detection to support rescue units in human location assessment in the underground mine. The presented method is based on measuring the dissimilarity between the subsequent short-time power spectra and the referential spectrum characterizing the UAV’s ego-noise. This relatively general and data-driven approach is applied both to generated narrowband harmonic patterns and to the human voice. As the analyzed signals of interest are of specific frequency content they can be selected from the background noise with the use of band-pass filtering.
Gross alpha and gross beta activities measurements in groundwaters using liquid scintillation counting (LSC)
Authors: Kowalska A , Maciejewski P , Szczęśniewicz M 
Published: December 2021

Abstract
In this work Authors describe the methodology of gross alpha and gross beta activities determination in water samples. The chosen method is dedicated to LSC and is based on ISO 11704:2018 and it is suitable for ground waters with low and medium salinity, especially drinking or tap waters as well as medicinal waters (with healing properties, using in health resorts). Authors describe the proper sampling, laboratory preparation including radon removal and measurements conditions. The local and European law regulations showing the limits of radioactivity of drinking waters and medicinal waters are presented. This work presents also selected data of gross alpha and gross beta activities from selected research: the highest levels is measured in Jordanian (gross alpha) and in Brazil (gross beta) and it is respectively 3.58 Bq/L and 5.22 Bq/L.
Counting trees - methods of automatic analysis of photogrammetric data in forests of the continental region
Authors: Budnik K , Byrtek J , Kapusta A 
Published: December 2021

Abstract
The paper is devoted to the methods of automatic analysis of photogrammetric data in forests of the continental region. It also discusses how automatic tree counting can be used to manage forests. Experimental research was conducted to verify two methods: Faster R-CNN and Template Matching to automatically detecting tree objects in the continental region characterized by mixed forests with a large predominance of conifers. The research was done based on photogrammetric data taken in four areas belonging to forest districts subordinate to the Regional Directorate of State Forests in Zielona Góra. Data was collected from drones and small airplanes with a photogrammetric container. The results show that both methods can be used for analyzes in specific cases. Moreover, the level of Recall shows the advantage of Faster R-CNN methods for the photogrammetric data collected during the flights in various weather conditions.
Review of vegetation indices for studies of post-mining processes
Authors: Pawlik M , Rudolph T , Benndorf J , Blachowski J 
Published: December 2021

Abstract
Each phenomenon has its cause and effect. During the research on the post-mining processes, the reasons can be found in ongoing processes taking place after the end of the mining exploitation. Therefore, a very important aspect is Geomonitoring. Currently, the post-mining processes taking place all over the world, should be considered into two groups of processes: such taking place in subsurface regions and such on the surface on the Earth. Through an integrated Geomonitoring it is possible to observe, among others, the vegetation of the mining areas. The observation of the state of vegetation is an aspect of research using remote sensing methods, e.g. indicators of vegetation. Of course, the reduction of plant vegetation may be caused by other reasons as well. Therefore, an important aspect is to distinguish changes in vegetation resulting affects coming from natural factors (climate changes, long-term droughts or sudden weather phenomena) and the resulting from post-mining processes. This article presents the indicators that have been discovered and used in the research of plant vegetation, which can be used in the post-mining.
LiDAR-based Simultaneous Localization and Mapping in an underground mine in Złoty Stok, Poland
Authors: Trybała P 
Published: December 2021

Abstract
The mining sector is one of the most promising areas for implementing advanced autonomous robots. The benefits of increased safety, robot actions’ repeatability, and reducing human presence in hazardous locations are especially important in underground mines. One of the core functionalities of such a device is the robot’s ability to localize and navigate itself in the working environment. To achieve this, simultaneous localization and mapping (SLAM) techniques are used. In selected cases, they also allow the acquisition of dense spatial data in the form of 3D point clouds, which can be utilized for various 3D modeling and spatial analysis purposes. In this work, a mobile robot, equipped only with a compact laser scanner, is used to acquire spatial data in the adit of a closed mine in Zloty Stok, Poland. This data is further processed with selected SLAM algorithms to create a homogeneous 3D point cloud. Results are visualized and compared to a model obtained with a survey-grade laser scanner. Accuracy evaluation shows that employing SLAM algorithms to process data collected by a mobile robot can produce a reasonably accurate 3D geometrical model of an underground tunnel, even without incorporating any additional sensors.
A thermogelling organic-inorganic hybrid hydrogel with excellent printability, shape fidelity and cytocompatibility for 3D bioprinting
Authors: Hu Chen , Ahmad Taufiq , Haider Malik Salman , Hahn Lukas , Stahlhut Philipp , Groll Jürgen , Luxenhofer Robert 
Published: December 2021

Abstract
Alginates are the most commonly used bioink in biofabrication, but their rheological profiles make it very challenging to perform real 3D printing. In this study, an advanced hybrid hydrogel ink was developed, a mixture of thermogelling diblock copolymer, alginate and clay i.e. Laponite XLG. The reversible thermogelling and shear thinning properties of the diblock copolymer in the ink system improves handling and 3D printability significantly. Various three-dimensional constructs, including suspended filaments, were printed successfully with high shape fidelity and excellent stackability. Subsequent ionic crosslinking of alginate fixates the printed scaffolds, while the diblock copolymer is washed out of the structure, acting as a fugitive material/porogen on the (macro)molecular level. Finally, cell-laden printing and culture over 21 d demonstrated good cytocompatibility and feasibility of the novel hybrid hydrogels for 3D bioprinting. We believe that the developed approach could be interesting for a wide range of bioprinting applications including tissue engineering and drug screening, potentially enabling also other biological bioinks such as collagen, hyaluronic acid, decellularized extracellular matrices or cellulose based bioinks.
Dual-working mode device based on dual-element photonic crystal-stepped concave waveguide
Authors: Li Zizheng , Wang Jianping , Chen Hongyao , Lu Huimin , Zhu Yifan , Bai Bing 
Published: December 2021

Abstract
In this study, a Si3N4 on insulator device used for photonic integrated circuits (PICs) is proposed. The dual-working mode device is constructed using a racetrack microring resonator, which is established using a dual-element photonic crystal-stepped concave waveguide. A novel scheme of dual-working modes is realized, and sensing and filtering are performed simultaneously without interference. The results show that a sensitivity of 29 pm K−1 and a line width of 0.28 nm are obtained for the sensor mode. An extinction of 41.8 dB and bandwidth of up to 305.5 nm are achieved in the filter mode. The footprint of the entire device is within 20 μm × 11 μm, which is ultra-compact and suitable for PICs.
Influence of light polarization state on the imaging quality of dark-field imaging system
Authors: Chen Dan , Wang Yuqin , Zhang Rongzhu 
Published: December 2021

Abstract
Annular linear polarized light is used as the illumination source of a reflective dark-field detection system in this paper. According to the theories of the bidirectional reflectance distribution function and multi-beam interference, the influence of the light polarization state on the intensity distribution of the scattered light is analyzed in detail. For surface defects, a simulation model of dark-field imaging is established based on the finite-difference time-domain method. Both the near-field and the far-field scattering intensity distributions caused by surface defects are calculated under different illumination conditions. The incidence angle and polarization state of the illuminated light are optimized. Simulation and experimental results show that the image quality will be minimally affected by the interference effect, while P-polarized light illuminates with an incident angle of 45°. The higher measurement accuracy of the dark-field imaging detection system can be obtained when the optimized illumination scheme is used.
Fried’s coherence length measurement of dynamic Kolmogorov type turbulence using the autocorrelation function
Authors: Lekshmi S R , Naik Dinesh N , Narayanamurthy C S 
Published: December 2021

Abstract
A new method to find the Fried’s coherence length of a dynamic Kolmogorov type turbulence in a laboratory environment is reported in this paper. This method utilises the autocorrelation function obtained from the quantitative characteristics of a rotating pseudo random phase plate in one of the arms of a Mach–Zehnder interferometer. Theoretical formalism and experimental verification are presented.
The tribological performance of W-DLC in solid–liquid lubrication system addivated with Cu nanoparticles
Authors: Li Dongshan , Kong Ning , Li Ruishan , Zhang Boyang , Zhang Yongshun , Wu Zhiguo , Zhang Qingdong 
Published: December 2021

Abstract
Judicious selection of additives having chemical and physical compatibility with the DLC films may help improving the triboligical properties and durability life of DLC-oil composite lubrication systems. In this study, Cu nanoparticles were added to PAO6 base oil to compose a solid-liquid composite lubrication system with W-DLC film. The effects of nanoparticle concentration, test temperature and applied load on tribological performance were systematically studied by a ball-on-disk friction test system. The tribological results illustrated that Cu nanoparticles could lower the coefficient of friction (COF) and dramatically reduce the wear rates of W-DLC films. The optimal tribological behavior was achieved for the 0.1 wt% concentration under 30 °C and the applied load of 100 N. The test temperature and applied load were vital influencing factors of the solid–liquid lubrication system. The bearing effect and soft colloidal abrasive film of spherical Cu nanoparticle contributed to the excellent tribological performance of the composite lubrication system under mild test conditions, meanwhile, the local delamination of W-DLC film and oxidation were the main causes of the friction failure under harsh test conditions. With test temperature and applied loads increase the degree of graphitization of the W-DLC film increased. In conclusion, there are several pivotal factors affecting the tribological performance of solid–liquid lubrication systems, including the number of nanoparticles between rubbing contact area, graphitization of the worn W-DLC films, tribofilms on the worn ball specimens and oxidation formed in friction test, and the dominant factor is determined by the testing condition.
Experimental analysis of surface finishing properties in magnetically assisted abrasive finishing of ASTM B16 brass
Authors: Singh Palwinder , Singh Lakhvir 
Published: December 2021

Abstract
Magnetically assisted abrasive finishing (MAAF) presents an attractive concept of surface and edge finishing by fine magnetic abrasive particles (MAPs). This study aims to contribute an experimental evaluation of the effect of process parameters viz. magnetic field density (MFD), circumferential speed of workpiece, and abrasive grit size on the surface finishing properties in MAAF when experiments were performed for finishing pipes of ASTM B16 brass material with the sintered MAPs. The developed model is based on the obtained experimental data accompanied by Box- Behnken design (BBD) of response surface methodology (RSM) analysis. Apart from deciding significant parameters, this analysis also presents the modeling of finishing properties and optimizes the desired performance parameters. Analysis of variance (ANOVA) includes data of standard deviation, coefficient of determination (R2), adjusted, and predicted (R2). MFD and speed show a significant effect on both the responses viz. surface roughness improvement rate (SRIR) and material removal rate (MRR). Analysis has shown that abrasive grit size is the most dominant parameter towards SRIR followed by MFD. The maximum SRIR of 88.12% (minimum Ra 50 nm) and 4.28 mg min−1 is achieved through multi-objective optimization with 0.8 T MFD, 500 rpm speed, and 300 μm grit size. The mathematical models of SRIR and MRR were also developed using RSM, focusing on varying MFD, speed, and grit size which can be used to predict the desired surface finishing properties. The model generated for SRIR, and MRR has an error of 0.204% and 2.506% respectively. Further SEM images were taken to understand the surface appearance of the finished surface.
PLGA-based drug delivery system for combined therapy of cancer: research progress
Authors: Ruirui Zhang , He Jian , Xu Ximei , Li Shengxian , Peng Hongmei , Deng Zhiming , Huang Yong 
Published: December 2021

Abstract
In recent years, PLGA micro/nano particle drug delivery systems has been widely used in cancer treatment. According to the unique properties of PLGA, carriers of various structures are designed to keep the function of drugs or bioactive substances, ensure the effective load of molecules and improve the bioavailability of drugs in diseased parts. PLGA is one of the earliest and most commonly used biodegradable materials. It is often used for functional modification with other polymers (such as polyethylene glycol and chitosan) or other molecules (such as aptamers and ligands) to deliver various small molecule drugs (such as DOX and DTX) and bioactive macromolecules (such as proteins and nucleic acids) to improve targeting, controlled release and therapeutic properties. In this paper, the preparation methods, physical and chemical properties and medical applications of PLGA micro/nano particles are discussed. We focused on the recent research progress of the PLGA-based drug carrier system in tumor combination therapy.