bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of synthesis and combustion of composite fuels based on n-decane and Al nanoparticles
Authors: Barmina E V , Zhilnikova M I , Kobtsev V D , Kostritsa S A , Orlov S N , Volkov S Yu , Shafeev G A
Published: December 2021

The article is devoted to the analysis of a diffusion combustion of a composite fuel (formed by an addition of non-oxidized aluminum (Al) nanoparticles (NP’s) to n-decane) with oxygen. The process of obtaining Al NP’s consisted of a laser fragmentation of initially large commercially produced NP’s (so called “Alex” with mean diameter is about 450 nm) in the solution of isopropanol. A final size distribution of NP’s was determined by a CPS DC2400 measuring disk centrifuge. The morphology of NP’s was characterized with the Transmission Electron Microscope (TEM) JEM-100C. The measured average diameter of NP’s was about 40 nm. In the final step of a preparation of a composite fuel an isopropanol was exchanged on n-decane. To characterize the composite fuel, diffusion combustion was used in combination with the laser diagnostic technique CARS. Temperature distributions along the x direction were measured at two values of distances from the nozzle. It has been shown that, for the fuel consistent of 0.1% mass concentration of Al NP’s in n-decane, the temperature at the distance equaled 14 mm downstream from the nozzle exit of a burner in the vicinity of the flame front was significantly higher (by 200–300 K) than that upon burning of pure n-decane.
Development of the optical electronic setup for carrying out measurements by multicolor Particle Image Velocimetry
Authors: Usmanova S S , Skornyakova N M , Belov Yu S , Sapronov M V , Kuchmenko A V , Kuchmenko V V
Published: December 2021

The paper is devoted to development of the optical electronic setup for carrying out measurements by multicolor particle image velocimetry. The main advantage of this method is the ability to visualize vector velocity fields in several planes simultaneously. As a result a 3D model of a setup was developed, a laboratory sample was assembled and series of testing experiments were performed. As a test object, vortex structure formed by a chemical stirrer in a cuvette with liquid has been considered. The experimental data were compared with the computer model developed in SolidWorks and FlowVision software.
Neuromorphic computing based on an antiferromagnet-heavy metal hybrid structure under the action of laser pulses
Authors: Yu Mitrofanova A , Safin A R , Kravchenko O V
Published: December 2021

The paper proposes a model of a neuromorphic processor, consisting of excitatory and processing neurons that are oscillators and detectors. The concept of neuromorphic computing, implemented by generating a spin current due to optical excitation of magnetic oscillations in an antiferromagnet is considered. The inverse spin Hall effect causes the generation of an electric current in the heavy metal layer. A constant driving current flows through the common bus. Magnetic oscillations in the receiving neuron occur due to the spin Hall effect. A biaxial nickel oxide crystal was used as a material for the base cells of AFM insulators and platinum was utilized as a heavy metal. The use of optical excitation can significantly increase the processing speed of neuromorphic computing with low power consumption. The presented model implements the simplest operations of neuromorphic computations, such as logical “OR”, “AND”.
Development and experimental testing of the technique of ultrasonic control of brazed joints of heat exchangers
Authors: Kostyukhin A S , Pavlukhin E A , Malyy V V
Published: December 2021

High reliability requirements are imposed on the quality of the soldered joints. Typical defects in the soldered joints of heat exchangers are non-soldered. The minimum size of the non-penetration area that must be detected is about 1 square millimeter. The existing assessment of the quality of soldering is reduced to destructive tests. These tests include hydraulic and pneumatic tests. There are control technologies that use non-destructive methods. For example, the applicability of the ultrasonic echo method based on thermo-optical (laser) excitation of ultrasonic waves has been proven. However, continuous inspection of the liquid-propellant engine chamber using the traditional echo method is not rational, since the inspection speed is limited by the size of detected defects (1 square millimeter) and amounts to a few millimeters per minute. In order to increase the scanning speed without losing the ability to reliably detect defects such as “non-soldered”, it is proposed to use phased array antennas (PA) as a means of implementing the ultrasonic echo method. The paper considers the issues related to the interpretation of the information obtained when scanning the soldered joint, as well as issues related to modeling the acoustic field in the model of the soldered joint of the heat exchanger.
Cell-derived extracellular matrix enhanced by collagen-binding domain-decorated exosomes to promote neural stem cells neurogenesis
Authors: Zhai Yuanxin , Wang Quanwei , Zhu Zhanchi , Zheng Wenlong , Ma Sancheng , Hao Ying , Yang Lingyan , Cheng Guosheng
Published: December 2021

Enhancing neurogenesis of neural stem cells (NSCs) is crucial in stem cell therapy for neurodegenerative diseases. Within the extracellular microenvironment, extracellular matrix (ECM) plays a pivotal role in modulating cell behaviors. However, a single ECM biomaterial is not sufficient to establish an ideal microenvironment. As multifunctional nanocarriers, exosomes display tremendous advantages for the treatments of various diseases. Herein, collagen binding domain peptide-modified exosomes (CBD-Exo) were obtained from the SH-SY5Y cell line infected with lentivirus particles encoding CBD-lysosome associated membrane glycoprotein 2b (CBD-Lamp2b) to improve the binding efficiency of exosomes and ECM. An exosomes-functionalized ECM (CBD-Exo/ECM) was then constructed via the interaction between CBD and collagen in ECM. Then, CBD-Exo/ECM was employed as a carrier for NSCs culture. The results showed that CBD-Exo/ECM can support the neurogenesis of NSCs with the percentage of proliferation marker EdU-positive (35.8% ± 0.47% vs 21.9% ± 2.32%) and neuron maker Tuj-1-positive (55.8% ± 0.47% vs 30.6% ± 2.62%) were both significantly increased in the exosomes-functionalized ECM system. This exosomes-functionalized ECM was capable to promote the cell proliferation and accelerate neuronal differentiation of NSCs, providing a potential biomedical material for stem cell application in tissue engineering and regenerative medicine.
Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warming
Authors: Park Bo-Joung , Min Seung-Ki , Weller Evan
Published: December 2021

Summer season has lengthened substantially across Northern Hemisphere (NH) land over the past decades, which has been attributed to anthropogenic greenhouse gas increases. This study examines additional future changes in summer season onset and withdrawal under 1.5 °C and 2.0 °C global warming conditions using multiple atmospheric global climate model (AGCM) large-ensemble simulations from the Half a degree Additional warming, Prognosis and Projected Impacts project. Five AGCMs provide more than 100 runs of 10 year length for three experiments: All-Hist (current decade: 2006–2015), Plus15, and Plus20 (1.5 °C and 2.0 °C above pre-industrial condition, respectively). Results show that with 1.5 °C and 2.0 °C warmer conditions summer season will become longer by a few days to weeks over entire NH extratropical lands, with slightly larger contributions by delay in withdrawal due to stronger warming in late summer. Stronger changes are observed more in lower latitudes than higher latitudes and largest expansion (up to three weeks) is found over East Asia and the Mediterranean. Associated changes in summer-like day frequency is further analyzed focusing on the extended summer edges. The hot days occur more frequently in lower latitudes including East Asia, USA and Mediterranean, in accord with largest summer season lengthening. Further, difference between Plus15 and Plus20 experiments indicates that summer season lengthening and associated increases in hot days can be reduced significantly if warming is limited to 1.5 °C. Overall, similar results are obtained from Coupled Model Intercomparison Project phase 5 coupled GCM simulations (based on RCP8.5 scenario experiments), suggesting a weak influence of air-sea coupling on summer season timing changes.
Historical food consumption declines and the role of alternative foods
Authors: Ferraro Danielle M , Cottrell Richard S , Blasco Gordon D , Froehlich Halley E , Halpern Benjamin S
Published: December 2021

The adoption of sustainable alternative foods could potentially reduce the environmental burden of human food production if it can reduce demand for products with higher environmental impact. However, there is little empirical evidence for how frequent food consumption declines are when alternative foods are introduced, limiting our knowledge of the potential for such introductions to drive food system transformations. Using 53 years of food supply data for 99 crop, livestock, and seafood commodities in 159 countries, we use regression analyses on 12 883 time series—each representing a single country-commodity pair—to detect sustained declines in apparent national food consumption, as well as corresponding consumption increases of other food commodities. First, we show that sustained declines in the consumption of any food item are rare, occurring in 9.6% of time series. Where declines are present, they most frequently occur in traditional plant-based staples, e.g. starchy roots, and are larger compared to animal-source foods, particularly in low- and middle-income countries where much of the future increase in food demand is expected to occur. Second, although declines were rare, we found national production rather than trade was identified as the most common proximate driver of declines in consumption, suggesting that shifts in diets have the potential to translate into reduced environmental impacts from food production. Third, we found consumption increases were nearly twice as common as declines, but only 8% of declines (from within 4% of total time series) occurred parallel to incline events within the same food group, suggesting limited interchangeability. An examination of case studies suggests that alternative foods can facilitate food system transitions, but strong relative disadvantages for existing foods across aspects of technology, markets, policy and culture need to exist in parallel to support for alternative foods across the same factors. Where existing foods are already produced in highly efficient systems, a lack of systematic disadvantage may provide a barrier to alternative foods driving change.
Offshore fresh groundwater in coastal unconsolidated sediment systems as a potential fresh water source in the 21st century
Authors: Zamrsky Daniel , Essink Gualbert H P Oude , Sutanudjaja Edwin H , van Beek L P H (Rens) , Bierkens Marc F P
Published: December 2021

Coastal areas worldwide are often densely populated and host regional agricultural and industrial hubs. Strict water quality requirements for agricultural, industrial and domestic use are regularly not satisfied by surface waters in coastal areas and consequently lead to over-exploitation of local fresh groundwater resources. Additional pressure by both climate change and population growth further intensifies the upcoming water stress and raise the urgency to search for new fresh water sources. In recent years, offshore fresh groundwater (OFG) reserves have been identified as such a potential water source. In this study, we quantify, for the first time, the global volume of OFG in unconsolidated coastal aquifers using numerical groundwater models. Our results confirm previously reported widespread presence of OFG along the global coastline. Furthermore, we find that these reserves are likely non-renewable resources mostly deposited during glacial periods when sea levels were substantially lower compared to current sea level. We estimate the total OFG volume in unconsolidated coastal aquifers to be approximately 1.06 ± 0.2 million km3, which is roughly three times more than estimated previously and about 10% of all terrestrial fresh groundwater. With extensive active and inactive offshore oil pumping present in areas of large OFG reserves, they could be considered for temporary fresh groundwater exploration as part of a transition to sustainable water use in coastal areas on the long run.
Zeros of the isomonodromic tau functions in constructive conformal mapping of polycircular arc domains: the n-vertex case
Authors: Carneiro da Cunha Bruno , Abarghouei Nejad Salman , Anselmo Tiago , Nelson Rhodri , Crowdy Darren G
Published: December 2021

The prevertices of the conformal map between a generic, n-vertex, simply connected, polycircular arc domain and the upper half plane are determined by finding the zeros of an isomonodromic tau function. The accessory parameters of the associated Fuchsian equation are then found in terms of logarithmic derivatives of this tau function. Using these theoretical results a constructive approach to the determination of the conformal map is given and the particular case of five vertices is considered in detail. A computer implementation of a construction of the isomonodromic tau function described by Gavrylenko and Lisovyy (2018 Commun. Math. Phys.
363 1–58) is used to calculate some illustrative examples. A procedural guide to constructing the conformal map to a given polycircular arc domain using the method presented here is also set out.
Record statistics for random walks and Lévy flights with resetting
Authors: Majumdar Satya N , Mounaix Philippe , Sabhapandit Sanjib , Schehr Grégory
Published: December 2021

We compute exactly the mean number of records ⟨R

N
⟩ for a time-series of size N whose entries represent the positions of a discrete time random walker on the line with resetting. At each time step, the walker jumps by a length η drawn independently from a symmetric and continuous distribution f(η) with probability 1 − r (with 0 ⩽ r < 1) and with the complementary probability r it resets to its starting point x = 0. This is an exactly solvable example of a weakly correlated time-series that interpolates between a strongly correlated random walk series (for r = 0) and an uncorrelated time-series (for (1 − r) ≪ 1). Remarkably, we found that for every fixed

r
∈

0
,
1

and any N, the mean number of records ⟨R

N
⟩ is completely universal, i.e. independent of the jump distribution f(η). In particular, for large N, we show that ⟨R

N
⟩ grows very slowly with increasing N as

⟨

R

N

⟩

≈

(

1
/

r

)

ln

N

for 0 < r < 1. We also computed the exact universal crossover scaling functions for ⟨R

N
⟩ in the two limits r → 0 and r → 1. Our analytical predictions are in excellent agreement with numerical simulations.
The predator-dependent replicator dynamics
Authors: Braga Ian , Wardil Lucas
Published: December 2021

Ecological interactions are central to understanding evolution. For example, Darwin noticed that the beautiful colours of the male peacock increase the chance of successful mating. However, the colours can be a threat because of the increased probability of being caught by predators. Eco-evolutionary dynamics takes into account environmental interactions to model the process of evolution. The selection of prey types in the presence of predators may be subjected to pressure on both reproduction and survival. Here, we analyze the evolutionary game dynamics of two types of prey in the presence of predators. We call this model the predator-dependent replicator dynamics. If the evolutionary time scales are different, the number of predators can be assumed constant, and the traditional replicator dynamics is recovered. However, if the time scales are the same, we end up with sixteen possible dynamics: the combinations of four reproduction’s games with four predation’s games. We analyze the dynamics and calculate conditions for the coexistence of prey and predator. The main result is that predators can change the equilibrium of the traditional replicator dynamics. For example, the presence of predators can induce polymorphism in prey if one type of prey is more attractive than the other, with the prey ending with a lower capture rate in this new equilibrium. Lastly, we provide two illustrations of the dynamics, which can be seen as rapid feedback responses in a predator–prey evolutionary arm’s race.
Manifestation of “flower structures” in geophysical models of the Central Tien Shan
Authors: Bataleva E A , Nepeina K S
Published: December 2021

Based on the analysis of deep geophysical (geoelectric and seismic) models of the Central Tien Shan, structures with the morphology resembling the crown of palm trees or the shape of a flower were identified. Geoelectric models are considered along a series of regional profiles (75º, 76º, 76º 30’). The length of the profiles intersecting all the main tectonic structures of the Tien Shan ranges from 75 to 250 km. Particular attention was paid to those zones of concentrated deformation, where the tectonic regime combines the conditions of shear and lateral compression (transpression zones). The structure of the collisional - accretionary wedge of the Atbashi zone in the distribution of electrical and velocity characteristics of the geological section is considered. Geoelectric models plotted along a series of regional profiles identify areas of increased electrical conductivity and show “flower structures”. The integral picture of the distribution and morphology of zones of increased electrical conductivity in the segments of the Earth’s crust of the Central Tien Shan may reflect a discretely localized manifestation of palm tree structures due to the evolution of transpressive suture zones during the Hercynian and Alpine tectogenesis.
Integrated geological interpretation of remote sensing data (Boysun structural-tectonic zone)
Authors: Bikeeva L R , Kh Safarov Z , Yuldasheva M G , Akramova N M , Umarov Sh A
Published: December 2021

In recent years, remote sensing data are increasingly used in the practice of oil and gas prospecting. This article discusses the main methodological aspects of identifying oil and gas promising structures by using materials for interpreting remote sensing data and a complex of geological and geophysical data. Remotely sensed data exhibit a regional review of the various geological formations and tectonic fracture zone and faults that are otherwise not possible detection by human eyes on the ground. The method of structural interpretation space image allows you to: detail the internal structure of oil and gas regions; to reveal the position and features of the tectonic blocks, structures of the second and third (anticlines, synclines, monoclines, etc.) orders; identify major disruptive violations; identify chains of local structures; fix the transverse structural elements that determine tectonic fragmentation. By deciphering the remote sensing data, the distribution and nature of the lineament network marking disjunctive dislocations and zones of increased fracturing are revealed and analyzed, as well as ring structures are detected, which in most cases indicate local structures of the sedimentary cover at different depth sections. The lithology and lineament interpreted from these multi-level data were integrated with data collected from the ground.
The structural positions of the ophiolite complex in the Earth crust of the western Tien-Shan
Authors: Nurtaev B S , Tsai O G , Kurbanova D U
Published: December 2021

The westernmost parts of the Tien Shan region are located between two areas of crustal suturing, formed by the closure of the Turkestan Ocean, and probably the closure of a second ocean, the Gissar Ocean. Regional correlation of these sutures, however, has been problematic due to the lack of geological and geophysical data, as well as conflicting interpretations within the literature of various geological bodies. We summarize the information about Paleozoic ophiolites of westernmost parts of the Tien Shan for the international geoscientific audience from the literature and our own unpublished data. We focus on the best-known examples of Southern Tien Shan ophiolites which are remnants of Paleo-Asian Ocean, aligned in two main belts in Uzbekistan. Ophiolites reveal a wide age spectrum ranging from the Ordovician to the Devonian on the northern slope of Southern Tien Shan, and the Early Carboniferous on the southern slope. Considering all data on these ophiolites as well as regional considerations lets us conclude that a single ocean located subduction of the Turkestan Ocean basin under the northern Karakum-Tadjik terrane caused back-arc continentalo ruisft.i ngo iunththwearGdi ssar region in Early Carboniferous resulted in the formation of a small basin with oceanic crust. By late Carboniferous/early Permian times, both oceanic basins were subducted.
Comparative analysis of acoustic and electromagnetic emissions of rocks
Authors: Klyuchkin V N , Novikov V A , Okunev V I , Zeigarnik V A
Published: December 2021

Comparative analysis of acoustic and electromagnetic emissions recorded during the intact rock samples deformation and dynamic rupture of simulated crustal fault is presented. Specialized machines for uniaxial compression and shear tests of rock samples with identical data acquisition systems for both test cases were employed. Increase of acoustic emission was observed accompanied by significant rise of intensity and amplitude of electromagnetic signals at high stress of the rock samples under the uniaxial compression or dynamic failure in the spring-block model. Such correlation is consistent with the previous conclusions that an increase of electromagnetic emission may be considered as a rock failure precursor. Any specific characteristics of the detected electromagnetic signals to be used for prediction of impending rock failure or the earthquake fault rupture were not found. The similarity of electromagnetic signals and their spectra obtained at the press equipment and the spring-block model suggests that in both cases, the signals observed are generated by the crack formations and shear. The electromagnetic emission appeared only in dry samples. The samples saturated by water with the salinity of over 0.1% demonstrated no electromagnetic emission.
Calculation of lateral stresses for uniaxial compression of geomaterial samples
Authors: Kirilov A A , Sychev V N
Published: December 2021

A method is proposed for calculating the transverce stresses during uniaxial compression of geomaterial samples from the measured load and mutually perpendicular deformations. Analytical expressions connecting the indicated parameters are obtained. The dependences of the change in the calculated transverse stresses on time are plotted for various values of Poisson’s ratio. The difference in transverse stresses demonstrates a much greater sensitivity to mechanical stress than each transverse stress separately. Sharp changes in the values of the difference in transverse stresses are observed, which coincide with bursts of AE activity.
Effect of solar activity on electromagnetic fields and seismicity of the Earth
Authors: Tarasov N.T.
Published: December 2021

It is shown that bursts of intensity of ionizing electromagnetic radiation from the Sun, as well as geomagnetic storms, cause a statistically significant decrease in the total number of earthquakes on Earth. After bursts of ionizing radiation from the Sun, a statistically significant decrease in the total energy of earthquakes occurs, and after geomagnetic storms, its increase is observed. This is mainly due to an increase in the number of the strongest earthquakes with MS
> 7 after geomagnetic storms and a decrease in the number of such earthquakes after bursts of ionizing electromagnetic radiation from the Sun. During geomagnetic storms and for several days after them, the probability of occurrence of strong earthquakes increases more than two times, and after bursts of ionizing electromagnetic radiation from the Sun, this probability decreases almost twice.
Anamolous modulations of electromagnetic field during increased seismic activity
Authors: Mukhamadeeva V A
Published: December 2021

The article presents the results of electromagnetic monitoring and geomagnetic observation during increased seismic activity in eastern part of Bishkek geodynamic range (Northern Tien-Shan) in 2017. It includes brief description of seismic conditions of the territory being researched, as well as analyses of the correlation between changes in geophysical field parameters and the earthquakes.
The results of magnetotelluric studies on the profile of the Kuray depression – lake Teletskoye
Authors: Pospeeva E V , Potapov V V
Published: December 2021

The results of magnetotelluric studies (MTS) conducted in the western part of the Mountainous Altai region on the profile of the Kurai depression – lake Teletskoye are presented. The profile intersects two large tectonic units – the Mountainous Altai and Teletskaya, bounded by regional tectonic suturs of the Teletsko-Bashkausskiy, Northern Sayans, Shapshalskiy and other faults. The obtained data indicate a fairly fractional recent block divisibility of the Earth’s crust of the Mountainous Altai territory. It is shown that according to the characteristics of the electrical resistivity distribution within the studied profile, large blocks are distinguished that differ sharply in the features of the composition and structure of the Earth’s crust, as well as the manifestation intensity of deep processes. The sections constructed from magnetotelluric data allow us to trace the behavior of the main neotectonic disturbances, which are marked by subvertical zones with abnormally low resistivity values (1-5 Ohm·m).
The deep structure of the Salair fold-cover structure according to magnetotelluric studies
Authors: Pospeeva E V , Zhimulev F I , Novikov I S , Potapov V V
Published: December 2021

The results of magnetotelluric studies (MTS) performed within the Salair cover-folded structure on two profiles are considered: the Zabrodino village – the Rodnikovy village (1) and the Smaznevo village – the Kotino village (2). The profiles are oriented crosswise along the main structures and intersect Salair and the western part of the Kuznetskiy trough. The analysis of the obtained data showed that a subhorizontal underlying conducting zone is distinguished in the Earth’s crust of the Salair fold-cover structure, such zone is typical for intracontinental orogens. The zone is considered as a deep separation failure. The nature of the electrical resistance values distribution confirms the presence of the Salair thrust on the Kuznetskiy deflection. The Alambay ophiolite zone on the geoelectric section corresponds to a highly gradient region, indicating the suture zone of this structure. High resistivity values in the northern part of the Khmelevskoy trough are associated with the widespread development of granitoid massifs that are not covered by erosion.
Methods and results of long-term strong earthquakes forecast in the Uzbekistan territory
Authors: Artikov T U , Ibragimov R S , Ibragimova T L , Mirzaev M A , Rebetsky Y L
Published: December 2021

An approach to evaluate the current seismological situation in the Uzbekistan territory is presented. This approach is based on the regularities of seismic processes in strong-earthquake focal areas and the manifestation peculiarities of strong earthquakes in seismically active zones. At the first stage, within seismically active zones, areas with a high seismic activity matching the strong earthquake level were identified during the historical and instrumental observation periods. Considering the low variability in the direction of seismotectonic processes over tens and hundreds of years, which determines the modern stress state of seismically active structures, these areas were considered the most likely areas to experience strong earthquakes over the next few decades. Tectonophysical validation of the division of seismically active zones into areas with different potential hazards of strong earthquakes was carried out within the framework of cataclastic analysis method of rupture dislocations (CAM). At the second stage, temporal fluctuations in seismic regime parameters within the selected areas were studied. Based on the number of current anomalous features identified, the areas were ranked according to the occurrence probability of strong earthquakes over the next few years.
Macroseismic intensity attenuation equations for Central Asia earthquakes
Authors: Artikov T U , Ibragimov R S , Ibragimova T L , Mirzaev M A
Published: December 2021

Based on macroseismic survey data for strong earthquakes in Central Asia, the coefficients of attenuation of seismic intensities with distance in the Blake-Shebalin- and Kovesligethy -type equations were refined. A new generalized dependence of macroseismic intensity attenuation on distance, taking into account the depth of the earthquake hypocentre, were obtained. Relations between the minor and major axes of the ellipse approximating real isoseists depending on the shaking strength, source depth and earthquake magnitude were found. With the example of the territory of eastern Uzbekistan, the influence of the choice of the law of seismic intensity attenuation with distance on the obtained seismic hazard assessments is investigated.
Assessment of social aspects of seismic hazard
Authors: Danilova T I , Peretokin S A , Medvedeva N S , Akatova K N
Published: December 2021

This paper is intended to illustrate the applicability of the results obtained from the investigations of social aspects of seismic hazard of the Russian Federation (RF) through the example of the high-seismicity region – the Far Eastern Federal District (FED). Within the FED the comparison of the areas of various seismic zones as per regulatory maps of General Seismic Zoning dated 2016 (GSZ-2016) has been performed and population estimates for each zone have been obtained. For the first time population estimates for zones with increased seismic hazard – grades A, B and C as per GSZ-2016 – are provided. The data obtained may be used for the evaluation of additional risks for FED’s population.
Reliability of the belt conveyor bed when restoring failed roller supports
Authors: Listova M A , Dmitrieva V V , Sizin P E
Published: December 2021

The reliability of modern belt conveyors, whose length reaches tens of kilometers, is primarily determined by the reliability of the roller supports that support the belt and ensure its movement. As they wear out, some roller bearings fail and need to be repaired or replaced. The dynamics of the number of working roller supports is determined by the system of Kolmogorov equations. Their solution allows us to find the probabilities of finding the system in states with a different number of working elements. The article finds probabilities for two cases. In the first case, when restoring, only one roller support is repaired each time. In the second case, all roller supports are repaired or replaced. In the case of sequential recovery, the mathematical expectation of the number of properly working roller supports may be less than the total number by several units. There are always elements that need to be repaired. If the recovery rate of the elements is many times higher than the failure rate, the mathematical expectation of the number of properly operating roller supports is less than the total number of roller supports by less than one, during most of the time all roller supports are serviceable. In the case of simultaneous recovery of elements, an equally high level of reliability is achieved even with comparable failure and recovery rates.

The results obtained can be used to determine the necessary reserve of spare structural elements and to plan the maintenance of conveyors.
Replacement of traditional components of the backfill mixture with man-made waste
Authors: Khayrutdinov A , Paleev I , Artemov S
Published: December 2021

The formation and storage of man-made waste of water-soluble ores creates a global environmental problem that entails changing landscapes in mining areas and environmental degradation.

The involvement of man-made waste in a closed cycle of the production and technological chain makes it possible to reduce the impact of mining and processing on the environment. The use of non-waste (low-waste) technologies, in addition to reducing the environmental burden, allows you to expand the raw material base of the enterprise by replacing the traditional components of the backfill mixture with man-made waste from mining and processing enterprises.

The possibility of replacing the traditional, specially extracted aggregate in the backfill mixture with industrial waste of water-soluble ores is experimentally proved. The possibility of creating a cementless backfill mixture is proved. The possibility of replacing the cement binder with magnesium-containing slags of the Chusovsky Metallurgical Plant was confirmed. It was found that the separate activation treatment of the components of the backfill mixture has a positive effect on its rheological properties and increases the strength of the joint mass. The use of lignosulfonate improves the quality of the mixture and the resulting mass.

The development of a backfill composite from man-made waste makes it possible to implement the principle of organizing mining production, which provides for the use of intermediate products in cyclic production and excludes the formation of man-made waste of water-soluble ores.
Drill bit state-oriented drilling process classification with time-series data for wheeled drilling rigs
Authors: Ziętek Bartłomiej , Wodecki Jacek , Michalak Anna , Śliwiński Pawel
Published: December 2021

This paper represents an analysis of the wheeled drilling rig’s drilling process. Thanks to data from the onboard measurement unit of the machine, the characteristics of the drilling process regarding state of the drill bit are identified and calculated. The aim of the work is to provide a comparison between different drill qualities and process classification using Threshold-based segmentation with feed pressure levels and duration of single hole drilling. Second methodology is hierarchical clustering to create cluster analysis. Thanks to these approaches, it is possible to detect the time when the drill bit should be changed. The obtained results state that the average drill time for a new drill bit is shorter approximately by 50% than for the worn-out bit in terms of average drilling duration. Moreover, these changes are visible in the subsystem pressure level of the machine under specific drilling regimes.
Heat Balance Determination Methods for Mining Areas in Underground Mines - A Review
Authors: Wróblewski Adam , Banasiewicz Aleksandra , Gola Sebastian
Published: December 2021

Mine operation in presence of aerological hazards is a challenging issue for mine ventilation services. Increasing depth of exploitation and growing level of mechanization, due to the demand for intensification of extraction, makes it even more difficult regarding thermal hazard. As air temperature is a decisive factor shaping underground thermal working conditions it is extremely important to predict its value. This task determines the possibility of carrying out works in regions with the highest thermal hazard, where, due to the applicable regulations, it is necessary to use air conditioning to ensure appropriate working conditions for people. To determine the required cooling capacity for mining regions, it is crucial to identify the individual heat sources, as well as to define the amount of heat they generate. For this purpose, heat balances need to be set, taking into account the mentioned issues. The main goal of this paper is a presentation of methods available in the literature for determining the thermal balances of mining areas. The article also presents and characterizes the most important heat sources in underground mines. In addition, methods of determining heat fluxes from individual sources were indicated, as well as potential difficulties in the applicability of the above-mentioned methods for mining areas heat balances determination, in which, due to the current depth of exploitation, the thermal hazard is the most important natural hazard that determines the possibility of mining works.
Fault-related impulsive component detection for vibration-based diagnostics in the presence of random impulsive noise
Authors: Wodecki Jacek , Michalak Anna
Published: December 2021

In this paper, the authors propose the methodology for vibration-based diagnostics towards local damage detection in rolling element bearings in the presence of non-Gaussian noise. In real-life cases, the main problem making the analysis difficult is the non-Gaussianity of the high-energy noise present in the operational environment. Because of this fact, popular impulsiveness-related detection techniques cannot be used. In the presented article, a real-life data measured in an industrial scenario will be presented and a proposition of an approach to cyclic component extraction will be discussed. The proposed approach takes advantage of the Cyclic Spectral Coherence (CSC) map as multidimensional data representation. It can be very useful for indicating cyclic modulated components in the otherwise non-cyclic signal content. However, due to the limitations of statistics used in CSC map calculation impacting the quality of CSC map in the presence of non-cyclic impulsive behavior in the signal, Nonnegative Matrix Factorization idea is used as a method for component separation. The presented method allows for obtaining carrier-related and modulation-related features of the component of interest. The main advantage of the presented method is pairing very useful multidimensional data representation (CSC) with very potent decomposition technique (NMF), that allows to reconstruct separated components in the final stage of the analysis. As a consequence, the time series of the component can be reconstructed based on the carrier feature.
Analysis of the sound signal to fault detection of bearings based on Variational Mode Decomposition
Authors: Shiri Hamid , Wodecki Jacek
Published: December 2021

Damage detection in rotating machines is well established for vibration signals. Unfortunately, there are situations, where usage of vibration is not possible. Then, acoustic signal could be used instead. Unfortunately, usually acoustic signal are more noisy and require special treatment for obtain successful damage detection. In the paper we propose to use Variational mode decomposition (VMD) to omit noise for finding de-noise signal. We use vibration data to validate acoustic signal based procedure. The experiment was done on test rig with damaged bearings.
Fe, Ni, Co, and Cu in FeNi alloys of H Chondrites
Authors: Blutstein K , Pawliszyn S
Published: December 2021

This publication presents the results of chemical analyses of 173 FeNi alloy grains from four selected H ordinary chondrites: Thuathe, Chergach, Gao-Guenie and NWA 4555. Based on performed analyses and calculations, the following average chemical composition of the FeNi alloy was determined [in wt.%]: Fe - 90.75%; Ni - 8.80%; Co - 0.35%; Cu - 0.03%. The content of Cu and Co depends on the nickel content in the FeNi alloy. The low-nickel alloy represented by kamacite is enriched in cobalt (average content 0.38%) and depleted in copper (0.01%), while the high-nickel alloy, represented mainly by taenite, is characterized by a low content of cobalt (0.08%), and a significant enrichment in copper (0.16%). Based on these data, it is possible to approximate the resources of these metals in the parent bodies of these chondrites. For example, for the asteroid (143624) 2003 HMi6, which is classified as a Near Earth Object (NEO), such resources are [in Mg]: Fe - 2.4 · 109, Ni - 2.3 · 108, Co-9.2 · 106, Cu-7.9 · 105.
A review of methods in the field of detecting illegal open-pit mining activities
Authors: Kozińska P , Górniak-Zimroz J
Published: December 2021

Illegal open pit mining might be a very dangerous activity both for the environment and also for the people living in its neighbourhood. This kind of activity is connected with environmental degradation, disruption of sustainable development and lack of the most critical last stage of the mine’s “life”, i.e. land reclamation. An additional element connected with illegal exploitation is the fact of breaking the law and stealing mineral resources. Monitoring of illegal exploitation is therefore an important aspect. The presented here review was intended to investigate which methods can be used directly to detect open pit mining sites and to evaluate their effectiveness. In the reviewed works a wide variety of methods have been used, ranging from manual methods, such as photo-interpretation, to a combination of automatic methods and photo-interpretation, to fully automatic methods. Based on the analysis, it was indicated that different types of classification (supervised, unsupervised, hybrid) are the most commonly u sed. Besides, radar interferometry, image fusion techniques, or images spectral similarity are also used.
Degradation of urban space as a negative effect of mine closures
Authors: Kozlowska-Woszczycka A
Published: December 2021

The article presents one of the social aspects of mine closure, which concerns degraded urban space. One of the post-industrial districts of Waibrzych: Sobiecin was selected as a case study, in which the general condition of the buildings was assessed. The closure of mines is the last stage of mining activity, the result of which should be a permanent minimization of the negative consequences of the impact of the mining industry. The closure of mining enterprises has environmental, social and economic consequences. The liquidation of the Waibrzych coal mines in the 1990s resulted in a rapid de-industrialization of the region and did not provide the means to contain the domino effect it caused. At that time, economic and social changes began in Waibrzych, and unorganized and intense changes took place in the city space. Liquidation processes in the mining industry have led, among others, to the physical and aesthetic degradation of residential buildings and other facilities. The purpose of this article is to assess the general condition of buildings located in an area affected by the negative consequences of mine closures. To achieve this goal, an inventory of the technical condition of the buildings was made. The external elements of the building were assessed by means of a field interview: the facade, door and window joinery and roof covering. The inventory process was supported by drone flights. The collected data was used for graphic and tabular studies, summarizing the condition of buildings and the degree of degradation of urban space.
Augmented reality in the dynamic world of virtual tourism
Authors: Mudička Š , Kello J
Published: December 2021

The issue of virtual tourism penetrates the consciousness of many current explorers and visitors to interesting sites and local attractions. Is it really necessary to physically travel to the chosen location, sacrifice time, money and increase your carbon footprint? The article deals with the issue of creating an application using augmented reality for the presentation of 3D models of cultural monuments. The application is designed for mobile devices, on which museum visitors can view digital copies of selected objects of interest. They can also take a virtual tour of the museum through their mobile devices from the comfort of their home. The introductory part of the article describes surveying of shape and visual properties in situ using photogrammetry and laser scanning. The sequent chapters are an analysis of the creation of 3D models in real scale with photorealistic textures and their presentation in a mixed reality environment. In our case, we will specifically focus on the augmented reality application and its development in the Unity multiplatform game engine. The article aims to describe the development of a mobile marker-based AR application briefly, to demonstrate the possibilities of augmented reality and to indicate the potential benefits resulting from the integration of X-reality into our lives. Specifically, we will focus on the application of AR to cartographic works and the enrichment of the content of classical 2D map works and plans with virtually designed 3D models on their surface.
Lithological, structural and hydrothermal alteration mapping utilizing remote sensing datasets: a case study around Um Salim area, Egypt
Authors: Shebl A , Csámer Á
Published: December 2021

Remote sensing datasets have introduced remarkable advancements in mapping rock units, structural elements, and hydrothermal alteration zones. This study applied Landsat Operational Land Imager (OLI) multispectral dataset in discriminating the intricate basement of Um Salim area, Central Eastern Desert (CED), Egypt. Moreover, a panchromatic 15m pixel size band is implemented to extract the study area’s linear structural features. Several image processing methods including False Color Combination (FCC), Band Ratio (BR), Optimum Index Factor (OIF), and Density slicing were utilized in lithological and alteration mapping. The widely used, LINE module of the PCI Geomatica is applied for lineament extraction. Results reasonably discriminate the complicated rock units using selected composites depending on OIF results. A photo-geological map is constructed and shows greater coincidence with recently published maps. Lineaments map and its density revealed the preponderance of NE-SW and WNW-ESE structural trends. The spatial relationship between the resultant hydrothermally-altered zones and the detected structural features strongly recommends further detailed examination for ore deposits within the study area besides manifesting the efficiency of the utilized data and methods.
Quantification of dark-field effects in single-shot grid-based x-ray imaging
Authors: Lim Hyunwoo , Cho Hyosung , Lee Hunwoo , Jeon Duhee
Published: December 2021

Dark-field (DF) x-ray imaging (DFXI) is a technology that can obtain information relating to the small-angle x-ray scattering of a sample. In this paper, we report on the quantification of DF effects by measuring the real space correlation function of scattering samples in a single-shot grid-based x-ray imaging setup that enables a simple approach to DFXI. The experimental measurements of the DF effects in our imaging setup were in good agreement with the theoretical quantification over the entire range of test conditions, thus verifying its effectiveness for single-shot grid-based DFXI. Consequently, we were able to clearly understand the associated particle-scale selectivity, which can help us determine suitable applications for single-shot grid-based x-ray DFXI.
Partial spectral and temporal coherence of plane-wave pulse trains in second-harmonic generation
Authors: Pesonen Henri , Huusko Juha-Matti , Zang Xiaorun , Friberg Ari T , Turunen Jari , Setälä Tero
Published: December 2021

We study the spectral and temporal coherence effects in the passage of a Gaussian Schell-model (GSM) scalar, plane-wave pulse train through a slab of nonlinear optical crystal exhibiting second-harmonic generation. We show that due to the nonlinear interaction the temporal and spectral degrees of coherence of the fundamental (F) and second-harmonic (SH) pulse trains at the exit facet may deviate markedly from the GSM and the global degree of coherence of the SH wave generally decreases with increasing incident F beam intensity. In addition, we find that due to the partial coherence of the incident GSM field the transmitted SH wave may show a double-peaked intensity distribution.