bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing posterior cervical foraminotomy with anterior cervical discectomy and fusion in radiculopathic patients: an analysis from the Quality Outcomes Database
Authors: Mummaneni Praveen V. , Bisson Erica F. , Michalopoulos Giorgos , Mualem William J. , El Sammak Sally , Wang Michael Y. , Chan Andrew K. , Haid Regis W. , Knightly John J. , Chou Dean , Sherrod Brandon A. , Gottfried Oren N. , Shaffrey Christopher I. , Goldberg Jacob L. , Virk Michael S. , Hussain Ibrahim , Agarwal Nitin , Glassman Steven D. , Shaffrey Mark E. , Park Paul , Foley Kevin T. , Pennicooke Brenton , Coric Domagoj , Slotkin Jonathan R. , Potts Eric A. , Fu Kai-Ming G. , Asher Anthony L. , Bydon Mohamad
Published: April 2024

OBJECTIVE

The objective of this study was to compare clinical and patient-reported outcomes (PROs) between posterior foraminotomy and anterior cervical discectomy and fusion (ACDF) in patients presenting with cervical radiculopathy.

METHODS

The Quality Outcomes Database was queried for patients who had undergone ACDF or posterior foraminotomy for radiculopathy. To create two highly homogeneous groups, optimal individual matching was performed at a 5:1 ratio between the two groups on 29 baseline variables (including demographic characteristics, comorbidities, symptoms, patient-reported scores, underlying pathologies, and levels treated). Outcomes of interest were length of stay, reoperations, patient-reported satisfaction, increase in EQ-5D score, and decrease in Neck Disability Index (NDI) scores for arm and neck pain as long as 1 year after surgery. Noninferiority analysis of achieving patient satisfaction and minimal clinically important difference (MCID) in PROs was performed with an accepted risk difference of 5%.

RESULTS

A total of 7805 eligible patients were identified: 216 of these underwent posterior foraminotomy and were matched to 1080 patients who underwent ACDF. The patients who underwent ACDF had more underlying pathologies, lower EQ-5D scores, and higher NDI and neck pain scores at baseline. Posterior foraminotomy was associated with shorter hospitalization (0.5 vs 0.9 days, p < 0.001). Reoperations within 12 months were significantly more common among the posterior foraminotomy group (4.2% vs 1.9%, p = 0.04). The two groups performed similarly in PROs, with posterior foraminotomy being noninferior to ACDF in achieving MCID in EQ-5D and neck pain scores but also having lower rates of maximal satisfaction at 12 months (North American Spine Society score of 1 achieved by 65.2% posterior foraminotomy patients vs 74.6% of ACDF patients, p = 0.02).

CONCLUSIONS

The two procedures were found to be offered to different populations, with ACDF being selected for patients with more complicated pathologies and symptoms. After individual matching, posterior foraminotomy was associated with a higher reoperation risk within 1 year after surgery compared to ACDF (4.2% vs 1.9%). In terms of 12-month PROs, posterior foraminotomy was noninferior to ACDF in improving quality of life and neck pain. The two procedures also performed similarly in improving NDI scores and arm pain, but ACDF patients had higher maximal satisfaction rates.
АНАЛІЗ ЗАВДАНЬ МІСТОБУДІВНОГО ВІДНОВЛЕННЯ УРБАНІЗОВАНИХ ТЕРИТОРІЙ ЛУГАНСЬКОЇ ОБЛАСТІ
Authors: Соколенко К. В.
Published: April 2024

Досліджується вплив масштабів та характеру руйнувань внаслідок бойових дій у Луганської області на можливостівідтворення урбанізованих територій. Визначено завдання містобудівного відновлення урбанізованих територій, порушених бойовими діями.Доцільність відновлення об’єкта визначається здатністю забезпечити певну функцію містобудівної діяльності. Об’єктигрупуються за ознаками розміру територій та за принципом першочерговості відновлення об’єкта містобудування. Принцип ієрархічності та принцип комплексного розвитку визначають, що недоцільно планувати розвиток окремого міста, не враховуючи інтереси території. Завдання містобудівного відтворення урбанізованих територій та зруйнованих міст повинні враховувати принципи захищеності та безпеки, доступності, автономності, адаптивності, привабливості, екологічності та відтворення довкілля.Модель випереджаючої реконструктивної діяльності є пріоритетною.
Views of Students and Lecturers on Module Development in Learning Listening Skills in Higher Education
Authors: Ningsih Ayu Gustia , Indriyani Vivi , Kurniawati Eni
Published: April 2024

The aim of the initial research was to describe the potential that supports the implementation of listening skills using digital technology, namely the implementation of listening skills learning in the classroom, student characteristics, and the use of technology in developing teaching materials. The type of research used is descriptive. The research subject for lecturers in listening skills courses and students studying listening skills material in the Indonesian Language and Literature Education study program, Padang State University. The instruments used to collect data were observation sheets, questionnaire sheets, and listening skills test sheets. Data were analyzed using descriptive statistical analysis. The results of the preliminary research are: 1) The average score of students’ listening skills is still low so it needs to be improved. 2) The results of observations regarding the use of modules are still not utilized optimally, 3) The results of observations of digital teaching materials used by lecturers based on the LMS (Learning Management System) display conclude that not all lecturers use digital materials in the LMS, and 4) Results of student response questionnaires agree with the development of digital materials in the Learning Management System so that student learning outcomes improve. Based on the results of this preliminary study, it can be concluded that the modules currently used by lecturers in listening skills courses still need to be developed. The development of teaching materials is carried out by utilizing technology.
The Influence of Transformational Leadership Style, Work Environment, Job Satisfaction and Work Discipline on Employee Performance
Authors: Saharso Saharso , Fadilah Muhammad Fadjri
Published: April 2024

This research aims to analyze the influence of transformational leadership style, work environment, job satisfaction and work discipline on the performance of employees of PT Indomarco Prismatama Bogor 1 Branch. The analytical method s in this research are descriptive analysis and inferential analysis. Data analysis from several tests, namely ins trument testing, classical assumption testing, model feasibility testing, multiple liners analysis and t - hypothesis testing, was conducted. The subjects of this research were employees of PT Indomarco Pismatama Bogor 1 Branch, with a total of 119 employees using data collection methods via questionnaires. The results of the regression analysis in this research shows that there is a positive and significant influence on performance, which is shown in the coefficient table in the regression equation models. The results of the ANOVA statistical test for the feasibility of the model show significant results, so that the model used has a relationship with the performance variable.
On the Statistical Significance Test for the Procedure of Polarity Classification by Types of Acoustic Emission Sources
Authors: Smirnov V. B. , Isaeva A. V. , Kartseva T. I. , Patonin A. V. , Shikhova N. M. , Ponomarev A. V.
Published: April 2024

Using a mathematical statistics approach, we review the procedure for type classification of acoustic emission (AE) events into shear, tension, and collapse, proposed by Zang et al. (1998). The procedure is based on counting the signs of first pulses of waves arriving at acoustic sensors and is widely used in rock physics experiments. Under the assumption that the determination errors of first-pulse signs at sensors have uniform and independent distribution, the statistical significance and power of the type separation test are evaluated for a given number of sensors used. We consider and compare three methods of the construction of a statistical test based on the P-value approach and symmetric and asymmetric statistical hypothesis tests. Considering the results of the statistical study, we propose some practical recommendations for selecting a threshold to classify AE event types in experimental studies.
Neural Network Modeling of Electromagnetic Prediction of Geothermal Reservoir Properties
Authors: Spichak V. V. , Zakharova O. K.
Published: April 2024

This work conducts neural network modeling of temperature, thermal conductivity, and permeability predictions for depths greater than those drilled, as well as for the immediate vicinity of the exploratory borehole. For this purpose, we use data from three boreholes drilled earlier in the Soultz-sous-Forêts geothermal site (France) and the results of the magnetotelluric sounding performed there. It is shown that the relative accuracy of the predictions depends significantly on the relationship between the depth of the drilled borehole and the target depth of the prediction. For instance, for all the examined parameters, prediction errors become less than 5% if the prediction is made for depths that do not exceed the borehole depth by more than two times. In this case, the average errors of temperature and thermal conductivity predictions for the vicinity of the drilled borehole were 3.6% and 6%, respectively. The obtained results justified a new scheme for predicting the thermophysical and porosity/permeability properties of rocks while drilling exploratory geothermal boreholes.
Seismicity of the Western Sector of the Russian Arctic
Authors: Morozov . N. , Vaganova N. V. , Asming V. E. , Peretokin S. A. , Aleshin I. M.
Published: April 2024

The paper presents the results of many years of research on the compilation of a consolidated, refined, unified earthquake catalog for the western sector of the Russian Arctic for the entire instrumental observation period, in particular for the period from 1908 to 2020. The catalog includes data on recent seismicity in areas previously unavailable for detailed seismic monitoring. Based on the results of the study, we were able to more accurately determine the spatial distribution of seismicity in the region and compare the instrumental data with parameters of lineament-domain-focal (LDF, or, alternatively, lineament-domain-source (LDS)) models of the General Seismic Zoning maps (GSZ, from Russian term abbreviated as OSR)—OSR-97 and OSR-2016. In the western sector of the Russian Arctic, the highest seismicity is observed in the continent-ocean transition zone, in the Belyi Island, Novaya Zemlya and Severnaya Zemlya archipelagos. The very shelf of the Barents and Kara Seas is characterized by rare and scattered seismicity. The configuration, the maximum possible magnitudes, and the depths of the seismogenic layers in the LDF models of OSR-97 and OSR-2016 maps are not always consistent with the instrumental data and need a correction. The consolidated refined earthquake catalog can be used as a basis for the further research aimed at seismic hazard assessment of the territory, construction of geodynamic models, and study of the stress-strain state of the Earth’s crust.
Evolution of Sliding Along a Heterogenous Fault. A Large-Scale Laboratory Experiment.
Authors: Gridin G. A. , Kocharyan G. G. , Morozova K. G. , Novikova E. V. , Ostapchuk A. A. , Pavlov D. V.
Published: April 2024

A laboratory setup was constructed in IDG RAS to investigate the process of shearing the contact of rock blocks of one-meter scale. It was used to investigate deformation processes in a fault with a heterogenous structure of the sliding interface, which contained strong contact patches – analogs of the “asperity” in the model of Hiroo Kanamori. It is shown that when a large slip occurs, the rupture, that starts in the zone of maximal deficit of interblock displacement, cuts the segments of the fault with lower effective strength, the latter being decreased in previous deformation events. Those previous events may be “slow” slips with low seismic efficiency. In nature the events that “prepare” the fault interface for a large slip may be smaller earthquakes – foreshocks, or they can be either low frequency earthquakes or slow slip events, both can hardly be detected in seismic records. Thereupon a promising diagnostic indication is the shift of the spectrum of ambient seismic noise to lower frequencies caused by the decrease of fault stiffness.
Friction as a Factor Determining the Radiation Efficiency of Fault Slips and the Possibility of Their Initiation: State of the Art
Authors: Kocharyan G. G. , Besedina A. N. , Gridin G. A. , Morozova K. G. , Ostapchuk A. A.
Published: April 2024

A conceptual state of the art review of the research on fault zone shear resistance is presented. Recent works on the subject are analyzed in the context of the approaches formulated in the authors’ presentations at the Sixth Conference “Triggering Effects in Geosystems”. The analysis of the results obtained in the last two or three decades by different research teams shows that the frictional properties of the slip zone gouge play a determining role in the rupture initiation and propagation patterns. The refinement of the methods for processing the parameters of weak seismicity, aimed at estimating the “slowness” of microearthquakes confined to a fault zone, may lead to new approaches in fault zone monitoring to derive indirect information on the material composition of a fault slip zone and, thus, on its seismogenic potential. At present, such methods may be useful in solving the problems of reducing the damage caused by man-made earthquakes.
Seismotectonic Changes Before the M = 9.1 Sumatra Earthquake of December 26, 2004
Authors: Sobolev G. A. , Migunov I. N.
Published: April 2024

Records of vertical surface displacement velocities in the vicinity of broadband seismic stations located around the epicenter of the 9.1 magnitude Sumatra earthquake on December 26, 2004 are analyzed. During five years from 1996 to 2000, the COCO station, nearest to the epicenter and located at a distance of 1700 km from it, has recorded a steady daily behavior of seismic noise. In 2001, step-like distortions of the level of the recorded seismic noise appeared at this station. These distortions continued up to the time of the earthquake. The station also detected pulses above the diurnal behavior, with a gradual increase and subsequent decrease in the amplitude of the oscillations which lasted a few minutes. The pulses occurred under quiet weather conditions and geomagnetic activity. No such pulses were observed at stations more than 2000 km from the epicenter. It is hypothesized that before the earthquake, there had been a slip on the geological faults in the lithosphere of the Indian Ocean.
PMTOOLS: New Application for Paleomagnetic Data Analysis
Authors: Efremov I. V. , Veselovskiy R. V.
Published: April 2024

Abstract—This paper introduces PMTools (https://pmtools.ru), a novel cross-platform open-source web application designed for the analysis of paleomagnetic data. Our software offers a user-friendly interface and supports the most commonly used data formats in paleomagnetism, including .pmd, .dir, .pmm, .rs3, .squid, .vgp, and .gpml. It encompasses all the necessary functionalities for conducting principal component analysis of natural remanent magnetization and computing mean paleomagnetic directions along with corresponding virtual geomagnetic (paleomagnetic) poles. PMTools facilitates the application of various paleomagnetic tests to user data, such as the fold test, conglomerate test, and reversals test. Notably, the application allows for seamless import and export of paleomagnetic data (tables) in formats compatible with .csv and MS Excel. Additionally, all generated figures can be exported as high-quality vector graphics in .svg format, specifically designed for direct integration into publications and presentations. Furthermore, PMTools enables the export of sets of paleomagnetic poles in GMap and GPlates software formats, enabling researchers to promptly use their paleomagnetic data for paleotectonic reconstructions. PMTools has an intuitive interface, customizable hotkeys, and an extensive array of graph elements, all of which contribute to making PMTools an appealing, cutting-edge tool for processing and analyzing the results of paleomagnetic studies.
Joint Three-Dimensional Interpretation of AMTS and RMT-C Tensor Data in a Region Promising the Discovery of Primary Diamond Sources (Karelian Isthmus)
Authors: Shlykov A. A. , Saraev A. K. , Bobrov N. Yu.
Published: April 2024

Abstract—The paper presents the techniques and results of the joint interpretation of AMTS and RMT-C tensor data in the area of the Karelian Isthmus near the village of Yablonovka, promising the discovery of primary diamond sources. Earlier, according to drilling data, fluid-cataclastic breccias, fluidolites, were identified here, which, according to modern geological concepts, can be primary diamond sources. The site is located in the marginal part of the Pash-Ladoga rift zone and is characterized by a complex three-dimensional structure. Under these conditions, in the presence of a system of multidirectional faults, the joint interpretation of the AMTS and RMT-C tensor data was performed within a 3D model of the medium. To reduce the inversion execution time, an approach and a procedure for transforming the RMT-C data obtained in the intermediate zone of a controlled source to sounding curves corresponding to the plane wave model are proposed. The transformed RMT-C apparent resistivity curves were also used to correct the static shifts of the AMTS curves. A joint 3D inversion was performed taking into account the relief. The resulting model is in good agreement with the geological data obtained from the wells previously drilled near the work site. The geoelectric sections show zones of relatively increased resistivity, which may be associated with fluidolites. The developed approaches to the joint 3D interpretation of AMTS and RMT-C tensor data and the obtained information about the structure and properties of the basement rocks, rocks hosting fluidolites, and overlying sedimentary deposits, can be used in prospecting works for diamonds on the Karelian Isthmus and adjacent territories.
Ponderomotive Forces of Alfven Waves in the Earth’s Magnetosphere
Authors: Feygin F. Z. , Guglielmi A. V.
Published: April 2024

Abstract—This paper is devoted to the 80th anniversary of the discovery of Alfven waves, which play an important role in physics, radiophysics, astrophysics, and Earth physics. The emphasis is on the ponderomotive redistribution of plasma in the Earth’s magnetosphere under the action of Alfven and ion-cyclotron waves. At relatively small distances from the Earth the ponderomotive force is buoyant, i.e., is directed upwards, regardless of whether an Alfven wave propagates towards the Earth or away from it. In the near-equatorial zone of the central regions of magnetosphere waves in the Pc 1 range push the plasma to the minimum of geomagnetic field, so that a maximum of plasma density arises on the equator at a sufficiently high wave intensity. A bifurcation occurs at the magnetosphere’s periphery, and the maximum is split into two maxima, the distance between which increases while moving away from the Earth. The polar wind, acceleration of heavy ions, and fictitious nonlinearity of the surface impedance of the Earth’s crust are also briefly discussed.
Results of Estimating the Absolute Gravimetric Measurements at the Ledovo Fundamental Gravity Station and on the First Order Gravimetric Network of Russia
Authors: Koneshov V. N. , Drobyshev N. V. , Sermyagin R. A. , Razin’kova E. P.
Published: April 2024

Abstract—This work is aimed at estimating the long-term continuing measurements of the acceleration of gravity at the Ledovo fundamental gravity station and first order stations of the gravimetric network of Russia. The observations are carried out by absolute gravimeters beginning from the mid-1970s to the present time. It is shown that the observed value of the acceleration of gravity at the Ledovo station has a tendency to decrease during last 45 years; according to our estimates, the value decreased by 32 µGal. The measurements carried out at first order gravity stations in Russia after renewal of network maintenance are compared with measurements carried out in the 1980s.
Active Tectonics of North-Eastern Taimyr (Byrranga Mountains) and Questions of Seismo-Tectonic Regionalization of the Russian Arctic
Authors: Ovsyuchenko A. N. , Zhostkov R. A. , Edemskii D. E. , Sobisevich A. L. , Sysolin A. I. , Presnov D. A.
Published: April 2024

Abstract—In thus paper, we present the first results of complex geological and geophysical studies of active tectonics in the northeast of Taimyr, carried out during the expedition of the Northern Fleet and the Russian Geographical Society in 2020. At the foot of the Byrranga Mountains, a wide zone of active fault-folded tectonic deformations was identified and studied. The general kinematics of displacements is reverse-thrust with signs of shear. The structural style of young tectonic deformations bears a direct resemblance to well-studied structural analogues of the Central Asian seismic belt. The Taimyr seismotectonic zone reveals both spatial and genetic isolation. It has an individual model of the Late Cenozoic geodynamic evolution and modern seismotectonic regime, which differs sharply from the Laptev Sea rift zone adjacent to the east. A complex of geological and geophysical methods has shown high efficiency of application in the Arctic to identify young fault-fold structures, which are potential sources of strong earthquakes.
Variations of Geomagnetic Paleointensity Recorded in the Archeological Ceramics of the Late Bronze and Early Iron Ages in the Central Russian Plain
Authors: Pilipenko O. V. , Nachasova I. E. , Azarov E. S.
Published: April 2024

Astract—The paper reports petromagnetic and archeomagnetic studies of ceramic fragments of the Late Bronze and Early Iron ages from archeological sites of the Grishinskii Istok III, Tyukov hillfort, and Shishkino hillfort, which are located in the Oka River basin, Ryazan district, Russian Federation. In total, 43 determinations of geomagnetic field intensity were obtained for the time interval of 1500–400 B.C., including 10 determinations for ceramics of the Grishinskii Istok III, 11 determinations for ceramics of the Tyukov hillfort, and 22 determinations for ceramics of the Shishkino hillfort. The studied time interval is characterized by the elevated values of the geomagnetic field intensity of 55–59 μT, which are much higher than the average field intensity for the Russian Plain in the IV–first half of III millennium B.C. Obtained VADM values for central Russian Plain fall in a wide range of values obtained on the Georgian archeological sites located in the same longitudinal sector. A large scatter of data can be related both to the large error in 14C determination, which is comparable with the duration of the best studied time interval, and with the high rate of magnetic field variations within this time interval.
Preliminary Seismo-Tectonic Analysis of the Catastrophic Earthquake in South-Eastern Turkey on Feb 6, 2023
Authors: Simonov D. A. , Zakharov V. S.
Published: April 2024

Abstract—In this paper, we carried out a kinematic analysis of the movements of plates and blocks of the region based on a homogeneous database of displacement velocities of GNSS permanent monitoring stations for the region of southeastern Turkey, where strong earthquakes occurred on February 6, 2023. Along the East Anatolian fault zone from 2008 to 2018, the Arabian Plate was established to shift relative to the Anatolian Plate, corresponding to a left shift (without a normal component) at a rate of 1 cm/yr in the eastern part to 0.8 cm/yr in the western part. Displacements occurred along the Chardak fault, corresponding to a left-hand strike-slip fault, at a rate of less than 0.7 cm/year. The revealed kinematics is confirmed by focal mechanisms and cosesismic displacements of the studied earthquakes. The M7.5 earthquake that occurred directly on the Chardak fault is not an aftershock of the M7.8 earthquake, but is a relatively independent event. An analysis of the seismic regime shows that the stresses on the East Anatolian fault after the main event M7.8 are relieved by the first large latitudinal fault zone (the Chardak fault). The results of our study suggest that the counterclockwise rotation of the Anatolian and Arabian plates associated with the opening of the Red Sea Rift is most likely decisive for the general kinematics of the plates in the region.
Application of Cryogels to the Production of Fuel Briquettes from Finely Dispersed Carbon-Containing Wastes
Authors: Fufaeva M. S. , Manzhai V. N.
Published: April 2024

Methods for producing fuel briquettes with various finely dispersed fillers of natural and industrial origin, which are capable of oxidation (combustion) reactions, are described. It was established that elastic polymeric bodies, into which finely dispersed fillers of a hydrocarbon nature were preliminarily introduced, were formed after a freeze–thaw cycle of the aqueous solutions of polyvinyl alcohol. Samples of fuel briquettes with a calorific value of 14.2 to 28.8 MJ/kg and a compressive strength of 2.14 to 2.9 MP were obtained for the associated utilization of industrial waste.
Nitrogen-Containing Bases of Bituminous Oils
Authors: Gerasimova N. N. , Sagachenko T. A. , Min R. S.
Published: April 2024

Structural group analysis and gas chromatography–mass spectrometry were used to characterize high- and low-molecular-weight nitrogen-containing bases of bituminous oils from various oil and gas provinces of Russia. It was found that the high-molecular-weight bases were similar in their structural organization: their averaged molecules were almost not different in the numbers of structural blocks and aromatic and naphthenic rings contained in them, and the numbers of carbon atoms in paraffin fragments. It was shown that the low-molecular-weight bases of all oils contained similar sets of alkyl-substituted quinolines, benzoquinolines, azapyrenes, and thiopheno- and benzothiophenoquinolines.
Thermolysis of Brown Coal in Water in the Presence of a Catalytic Additive Based on Iron Oxides
Authors: Kopytov M. A. , Boyar S. V.
Published: April 2024

The thermolysis of brown coal was carried out at temperatures of 360 and 380°C in water without a catalytic additive and in the presence of a catalyst based on iron oxides, and the composition of the products was studied. It was shown that the use of a catalytic additive in the course of the thermolysis of coal in water led to an increase in the yield of liquid and gaseous hydrocarbons; in this case, the fraction of maltenes in liquid products increased, and the concentrations of hydrogen and carbon oxides in gaseous products increased significantly.
Composition and Structure of the Asphaltene Components of Bituminous Oils
Authors: Kovalenko E. Yu. , Sagachenko T. A. , Min R. S. , Ogorodnikov V. D. , Perevezentsev S. A.
Published: April 2024

It was shown that the averaged asphaltene molecules of bituminous oils include no more than four structural blocks, the skeletons of which differ in the numbers of aromatic and naphthenic rings and the numbers of carbon atoms in alkyl substituents. The crystalline part of the macromolecules of the test asphaltenes had a layered structure. In terms of the number of layers of a packed structure, the thickness and the average diameter of its packing, and the number of aromatic rings in a layer, the test asphaltenes differed insignificantly.
Influence of Acid Reagents on Oil Sediment Formation
Authors: Prozorova I. V. , Yudina N. V.
Published: April 2024

The formation of oil sediment in highly paraffinic oil in the presence of carboxylic and naphthenic acids was studied. The influence of the concentration and composition of acids on the process of sediment inhibition and the concentrations of paraffins, resins, and asphaltenes in sediments was demonstrated. In the composition of sediments obtained from oil with the addition of acidic reagents, the amount of light n-alkanes increased and the fraction of higher molecular weight hydrocarbons decreased. The concentrations of aliphatic fragments and carboxyl groups in the resins of sediments obtained with the addition of acidic reagents decreased, and the aromaticity coefficient increased. Asphaltenes in the sediment were characterized by a decrease in the concentrations of aromatic structures and carboxyl groups.
Effect of Ultrasonic Treatment on the Properties of High-Paraffin Low-Resin Oil, Sediments, and Raffinates
Authors: Volkova G. I. , Zubarev D. A.
Published: April 2024

The effect of ultrasonic treatment on the properties of highly paraffinic oil, its sediments, and raffinates was studied. The oil was processed in an ultrasonic field (field intensity, 18 W/cm2; frequency, 22 kHz; and time, 10 min), and sedimentation was carried out at an ambient temperature of 30°C; the coldfinger temperature was 5°C. The viscosity–temperature parameters of oil were determined using a HAAKE Viscotester iQ rotational viscometer. The microstructure of the sediments was studied using an AXIOLAB.A1 microscope. The concentrations of weak and strong acids in oil, raffinates, and sediments isolated from highly paraffinic oil were determined using a potentiometric titration method.
Influence of the Conditions of Mechanical Processing of Oxidized Coal on the Properties of Humic Acids
Authors: Yudina N. V. , Savel’eva A. V.
Published: April 2024

The results of a study of the effect of mechanical energy on the properties of humic acids in the course of mechanical processing of oxidized coal in a planetary mill are presented. It is shown that, upon the mechanical action on coal in the presence of alkaline and oxidizing alkaline reagents in a planetary-type mill with steel balls used as grinding bodies, the yield of humic acids increased by 25–33%; the molecular weight decreased and the concentration of functional groups increased in comparison with those of humic acids obtained by mechanical processing with ceramic balls. A change in the density of balls affects the mechanics of their motion and the amount of energy during the fall.
Supramolecular Structure of Coals of the Metamorphism Series
Authors: Kuznetsov P. N. , Obukhova A. V. , Kositsyna S. S. , Kuznetsova L. I. , Kamenskii E. S. , Avid B.
Published: April 2024

The molecular structure characteristics of brown and hard coals of the metamorphism series were determined using IR spectroscopy. Based on the data of X-ray diffraction analysis and the kinetics of swelling in solvents, their supramolecular structure and the mechanism of molecular diffusion in the organic mass of coals were studied. Relationships between the supramolecular structure and molecular composition indices were established, and the structure evolution in the series of coal metamorphism was considered. It was found that tetrahydrofuran and quinoline molecules penetrated into the bulk of the organic mass of most coals by molecular Fickian diffusion complicated by steric hindrances of the microporous structure.
Evaluation of Mason’s Empirical Formula Using a Chain Model of Polycrystalline Graphite
Authors: Ershov A. A. , Dmitriev A. V. , Ershova A. A.
Published: April 2024

The dependence of the temperature of minimum electrical resistivity on the size of the mosaic blocks of artificial graphite of GMZ grade based on isotropic coke was calculated. A chain model of the electrical connection of lamellar structural elements (graphite flakes) was used. Compliance of the calculated results with Mason’s empirical formula was shown. Two cases were considered: the case of independence of the dimensions of mosaic blocks and the anisometry of the lamellar structural elements and the case when the dimensions of the mosaic blocks were proportional to the anisometry of the lamellar structural elements.
Production of Carbon Sorbents from Medium-Temperature Coke Siftings of Coking Plants in Central Kazakhstan
Authors: Muldakhmetov Z. M. , Gazaliev A. M. , Meiramov M. G. , Ordabaeva A. T.
Published: April 2024

The possibility of obtaining carbon sorbents from a fine fraction of medium-temperature coke for the removal of phenols from industrial water and wastewater was demonstrated. This excludes the carbonization of coal material as one of the economically costly stages. The resulting samples were tested for the ability to absorb phenol. The phenol content of water after purification with K12 and ShK sorbents decreased from 251.00 to 0.0572 and 0.737 mg/L, respectively.
Composition and Properties of Extraction Resins of Bitumens and Fulvic Acids of Brown Coal
Authors: Shpakodraev K. M. , Zherebtsov S. I. , Malyshenko N. V. , Votolin K. S. , Ismagilov Z. R. , Xintai Su
Published: April 2024

Proximate and ultimate analysis and 13C NMR and IR spectroscopy were used to characterize the samples of brown coal from the Tyulgan deposit of the South Ural basin (TBC), the naturally oxidized form of brown coal from the Tisulsky deposit of the Kansk-Achinsk basin (TBCO), and fulvic acids obtained from it. The component composition of bitumen was studied using gas chromatography–mass spectrometry (GC–MS) analysis. Data of a study on the phytostimulating activity of fulvic acids and their mixtures withthe saponifiable component of the resin of extraction bitumens in relation to wheat seeds of the Iren variety were presented. It was shown that the use of the saponifiable component of bitumen resins contributed to an increase in the phytostimulating activity.
Sorption of Metal Ions from Aqueous Solutions by Humic Substances
Authors: Ismagilov Z. R. , Smirnov V. G. , Malyshenko N. V. , Zherebtsov S. I.
Published: April 2024

Humic substances (HSs) extracted from brown coal, peat, and other sources are considered as anefficient and affordable sorbent used to trap and bind heavy metal ions, which are hazardous to the environment.This paper provides an overview of modern works on this subject matter. Typical structural characteristicsand properties of HSs and methods for their extraction from brown coal, peat, swamp waters, and othermedia are described, and quantitative results of a wide range of experiments on the sorption of metal ions byHSs are presented. Significant fluctuations in the measured sorption capacity of HSs in different experimentsprobably arise not so much due to variations in the elemental composition and structure of HSs extractedfrom different sources, but they are associated with experimental conditions, such as the acidity (pH) of solution,ionic strength, concentration of metal ions, and concentration of HSs in the solution. In terms of theorder of magnitude, the maximum sorption capacity of HSs is comparable to the total concentration of surfacecarboxyl and hydroxyl groups, and it amounts to several millimoles of metal ions per gram of HSs
Influence of the Phase Composition of the Fe/Biochar Catalysts on the Composition of Fischer–Tropsch Synthesis Products: The Lapidus Theory of Bifunctional Catalytic Centers
Authors: Ivantsov M. I. , Krysanova K. O. , Grabchak A. A. , Kulikova M. V.
Published: April 2024

Supported iron catalysts based on a carbon-containing material, biochar obtained by the hydrothermal carbonization of biopolymers (cellulose and lignin), were studied. The catalytic systems showed high activity in the Fischer–Tropsch synthesis. A composition of C5+ liquid products, uncharacteristic for ironcontaining catalysts, characterized by high isoalkane content (up to 55%) was recorded. This fact was discussed in the context of the theory of bifunctional centers proposed by A.L. Lapidus with coworkers. It was suggested that the active centers of the test catalysts can be considered bifunctional (a carbide phase and an oxide phase). A correlation between the Fischer–Tropsch synthesis data on the test catalysts and the data obtained by Lapidus and coworkers on cobalt-containing catalysts was shown.
Influence of Catalytic Poisons on the Selectivity of a Cobalt Catalyst for the Fischer–Tropsch Synthesis in Terms of the Theory of Astoichiometric Components of Catalytic Reactions
Authors: Krylova A. Yu. , Sviderskii S. A. , Kulikova M. V. , Lapidus A. L.
Published: April 2024

The effect of treatment of a freshly reduced cobalt catalyst with oxygen and ammonia on its properties in the Fischer–Tropsch synthesis was studied. It was shown that treatment with small amounts of catalytic poisons helped to increase the selectivity of the catalyst with respect to the formation of target products,linear C5+ hydrocarbons. The observed effect can be explained by partial blocking of the sites of direct CO hydrogenation to methane and modification of Lewis acid sites. The data obtained were consistent with the concept of the two-center surface model of Co catalysts for the Fischer–Tropsch synthesis and the theory of astoichiometric components of catalytic reactions.
Extraction of Rare Earth Elements from Brown Coals of the Sergeevskoe Deposit (Amur Region) According to Experimental Data
Authors: Radomskaya V. I. , Shumilova L. P. , Sorokin A. P. , Soktoev B. R. , Ivanov V. V. , Pavlova L. M.
Published: April 2024

A series of experiments on the leaching of rare earth elements (REEs) from Miocene brown coals of the Sergeevskoe deposit with water and alkaline and acid solutions was carried out. Using a set of methods (ICP MS, XRD analysis, heavy concentrate analysis, SEM EDS, and IR spectrometry), it was revealed that acid leaching was the most effective: 72–99% of REEs was extracted with a 1 M solution of hydrochloric acid in 24–48 h. This fact indicates that most of the REEs in the brown coals of the Sergeevskoe deposit were associatedwith the organic matrix in the form of complexes with the carboxyl groups of humic and fulvic acids. The high percentage of REE extraction indicates the possibility of using coals from the Sergeevskoe deposit as an easily enriched source of REEs.
Solid-Phase Reactions of Humic Acids with Sodium Percarbonate as a Way to Study Processes Occurring on the Mechanochemical Oxidation of Brown Coal
Authors: Skripkina T. S. , Yudina L. I. , Tikhova V. D. , Bychkov A. L. , Lomovsky I. O.
Published: April 2024

The reactions of humic acids in a pure form and in the composition of coal with sodium percarbonate occurring on solid-phase mechanochemical treatment were compared. Analysis for CHNO, IR spectroscopy, and potentiometric titration were used to study changes in the composition of humic acids mechanochemicallytreated after isolation from brown coal. The sorption properties in relation to heavy metal ions (Zn2+, Cu2+, and Cd2+) and their changes as a result of the treatment were studied. The results were correlated with data similar to those for humic acids in coal that underwent mechanochemical treatment. It was demonstrated that, at present, an increase in the yield of humic acids and the concentrations of phenolic and carboxyl groups in brown coal as a result of treatment with sodium percarbonate can be explained by the oxidation of fractions other than humic acids in the organic matter of brown coal.
Influence of Laser Irradiation on the Mechanism of Viscous Flow of Aqueous Sodium Chloride Solution
Authors: Shibryaeva L. S. , Komova N. N. , Kulikova I. Yu.
Published: April 2024

The effect of 632.8-nm radiation of a helium–neon laser on the viscosity of an aqueous sodium chloride solution has been studied. It has been shown that irradiation changes the nature and numerical values of the concentration dependence of viscosity. The concentration dependences of the viscous-flow activation energy for unirradiated and irradiated aqueous sodium chloride solutions have been determined. The influence of irradiation on the parameters of the power-law dependence of the solution viscosity on concentration has been analyzed, and the temperature dependences of these parameters have been determined. It has been concluded that laser irradiation alters the structural organization of the aqueous system and reduces
Influence of Mixture Composition on Electrophysical Parameters and Emission Spectra of
Tetrafluoromethane and Trifluoromethane Plasma with Nitrogen
Authors: Pivovarenok S. A. , Murin D. B. , Grazhdyan A. Yu.
Published: April 2024

The influence of the mixture composition on the electrophysical parameters and plasma emission spectra of mixtures of tetrafluoromethane and trifluoromethane with nitrogen under dc glow discharge conditions has been analyzed. It has been established that the reduced electric field strength changes nonlinearly with an increase in the proportion of the second gas in both mixtures. The reduced intensity of atomic fluorine emission in the CF4/N2 mixture is shown to pass through a maximum at a nitrogen volume fraction of 0.2, whereas a monotonic change in this dependence is observed for the CHF3/N2 mixture. The reduced emission intensities of CF2 radicals decrease monotonically with an increase in the nitrogen fraction in both mixtures.
Effect of Copper Ions on Quercetin Reactivity in Free Radical Reactions and Radioprotective Activity
Authors: Lysenko A. G. , Fenin A. A.
Published: April 2024

Steady state radiolysis showed a decrease in the reactivity of quercetin in free radical reactions with the 1-hydroxyethyl radical and the superoxide radical anion as a result of the formation of a complex with a copper ion. The negative effect of copper ions can be reduced via destroying the resulting complex by introducing chelating compounds, such as tartaric acid and EDTA. The nature of the change in reactivity corresponded to the change in the radioprotective activity of quercetin in relation to yeast cells.
Stabilization of Diffraction Gratings Recorded in Poly-N-epoxypropylcarbazole Films Doped with Iodoform
Authors: Sergeev S. A. , Robu S. V. , Meshalkin A. Yu. , Iovu M. S.
Published: April 2024

In poly-N-epoxypropylcarbazole films containing 10 wt % CHI3 as an additive, diffraction gratings with a period of about 1 μm have been recorded by electron-beam irradiation at various radiation doses. The influence of the duration of storage in the dark of diffraction gratings on their diffraction efficiency has been examined. A postradiation increase in the diffraction efficiency of gratings recorded at relatively low electron radiation doses was observed. The diffraction efficiency values stabilized approximately on the sixth day afterrecording the diffraction gratings.
Effect of Subdoses of Ultraviolet B Radiation on the Productivity of Spring Wheat (Triticum aestivum L.)
Authors: Surnina E. N. , Burenina A. A. , Astafurova T. P. , Mikhailova S. I. , Sosnin E. A. , Pak T. S. , Panarin V. A. , Nuzhnykh S. A.
Published: April 2024

Long-term field studies of the effect of presowing seed treatment of spring wheat (Triticum aestivum L.) with XeCl-excilamp UVB radiation on sowing qualities of seeds and plant productivity have been carried out. The features of morphogenesis at various stages of growth and development of wheat plants have been determined. A subdose of exposure has been identified that increases the crop yield. The studies prove the prospects of introducing UVB treatment into the pool of modern agricultural technologies.
Oxidative and Nonoxidative Conversion of Ethylene in Dielectric Barrier Discharge
Authors: Ryabov A. Yu. , Kudryashov S. V.
Published: April 2024

The oxidative and nonoxidative conversion of ethylene in a dielectric barrier discharge in the presence of water with the formation of predominantly unsaturated compounds (acetylene, butene, butadiene) has been studied. The efficiency of ethylene conversion in argon is shown in comparison with its oxidation by air into oxygenates. A simple theoretical estimate of the energy loss of discharge electrons in the feed gas mixture and simple kinetic calculations make it possible to explain both the change in the degree of ethylene conversion and the direction of the process
Atomic Hydrogen in Gamma-Irradiated Silicon Dioxide
Authors: Kuzina S. I. , Allayarov S. R.
Published: April 2024

The hyperfine structure of the components of the doublet EPR spectrum of atomic hydrogen in silicon dioxide (silica gel, quartz, or molybdenum glass) γ-irradiated at 77 K is due to the overlap of two doublets with α = 50.5 and 50.4 mT, a standard singlet and a resolved multiplet, responsible for the accumulation and stabilization of two types of surface and bulk atomic hydrogen. Surface hydrogen atoms formed upon thedissociation of surface OH groups and water molecules are stabilized in dry traps, and they have a standard doublet with α = 50.5 mT in the EPR spectra. Bulk hydrogen atoms are formed (upon radiolysis) and stabilized in internal water clusters of SiO2. In the water medium of clusters, bulk hydrogen atoms are affected by the protons of the water environment and, interacting with protons, they exhibit a multiplet doublet with α =50.4 mT in the EPR spectra. The contribution of the multiplet doublet to the total spectrum depends on the type of SiO2 and the radiation dose. The fraction of a multiplet doublet in macroporous glass at a dose of 120 kGy was 40%. When water was completely removed from a SiO2 matrix, bulk hydrogen atoms disappeared, and a standard doublet of atomic hydrogen was recorded in the EPR spectra after an irradiation dose of 40 kGy or higher
Investigation of Mechanical Properties and Structure of Irradiated Basalt Composites
Using IR Spectrometry
Authors: Oniskiv V. D. , Stolbov V. Yu. , Makarevich Yu. L.
Published: April 2024

The work is concerned with the study of a relatively new prospective composite material based on basalt fibers. In this work, an attempt has been made to investigate in more depth the structural changes that occur during irradiation of basalt composite samples by gamma ray streams and which affect the mechanical properties. The changes that have occurred during radiation modification have been evaluated by mechanical tests and infra-red spectrum investigations. The impact of the material structure on the elastic properties of the irradiated basalt composite is reasonably assumed. It is discovered that the modification of the material by gamma irradiation leads to an increase in the elastic properties of the basalt composite. At the same time the value of fracture strain decreases. Analysis of the IR spectrum in the high-frequency region showed that the radiation exposure results in continuing polymerization reactions and intermolecular cross-linking. However, when the radiation dose reaches 15 Mrad, there is a reduction in the number of bonds in the low-frequency region of the spectrum, which, according to the authors, corresponds to a breakdown of the aluminum-silicon-oxygen and organo-silicate frameworks
Radiation-Chemical Transformations of Ethylene Glycol and Its Deuterated Derivative
in Deaerated Aqueous Solutions
Authors: Urbanovich O. V. , Davydenko A. I. , Sverdlov R. L. , Bekish A. V. , Lastovskii S. B. , Tochilin E. V.
Published: April 2024

This study is devoted to the effect of complete deuteration of the ethylene glycol carbon skeleton on the formation of its radiation-induced free-radical transformations products in deaerated aqueous solutions at pH 7.00 ± 0.10 and a dose rate of 0.064 ± 0.002 Gy/s. It has been established that the chain process of fragmentation of carbon-centered ethylene glycol radicals (∙CH(OH)CH2OH) plays an important role in the formation of acetaldehyde. The replacement of protium atoms located at carbon atoms by deuterium decreased the radiation-chemical yield of acetaldehyde in aqueous 1 M solutions of diols by a factor of 8. The results of this study indicate that the use of deuterium exchange at the carbon skeleton of organic molecules is a promising way for increasing their resistance to radiation-induced free radical fragmentation processes.
Influence of Nonthermal Plasma Jet on the Surface Properties of Wheat Seeds
Authors: Baldanov B. B. , Ranzhurov Ts. V.
Published: April 2024

The change in the surface properties of wheat seeds under the influence of a nonthermal atmospheric-pressure plasma jet is shown. After plasma treatment, the surface of wheat seeds becomes hydrophilic and is characterized by a decrease in the contact angle, an increase in surface energy, and an increase in seed water uptake.