bluuebunny/crossref_metadata_2025 huggingface dataset:
Solid-state phase transition in n-alkanes of different parity
Authors: Gureva S A , Borisov A K , Marikhin V A , Egorov V M
Published: December 2021

The kinetics of the first-order solid-state structural transition in monodisperse n-alkanes samples of tricosane C23H48 and tetracosane C24H50 was studied by DSC and FTIR spectroscopy. The initial nuclei location of the new phase was revealed. The process of crystal structure rearrangement is initiated in the interlayers between neighboring lamellar for odd tricosane, while the nanonuclei in even tetracosane arise in the crystalline lamella cores. Thus, the influence of the number evenness of carbon atoms in the n-alkanes chains on the first-order structural phase transition has been proved.
III–V nanowires for ammonia detection
Authors: Kondratev V M , Kuznetsov A S , Gridchin V O , Fedina S V , Reznik R R , Nalimova S S , Moshnikov V A , Cirlin G E , Bolshakov A D
Published: December 2021

Ammonia is an inorganic agent found both in nature and in the human body, which is of great interest for modern sensory applications. Here we use GaP, GaN and GaAs epitaxial nanowires as sensitive elements of the ammonia sensors fabricated via a simple protocol on the platform with golden interdigital contacts. Impedancemetry is used to study change of the device properties with addition of ammonia to the reference medium (water). GaP and GaN-based devices exhibit sufficient response to the ammonia presence with the detection limit lower than 10ppm. This work is aimed at fabrication and study of precise, technological and relatively cheap ammonia sensors compatible with a liquid medium, and motivated by the possibility of using this type of adsorption sensors in medical, environmental equipment and biological purposes.
Study of hardness and morphology of carbide coatings obtained on complex shaped steel items by electro-spark alloying
Authors: Markelova O , Koshuro V , Fomin A , Aman A , Palis S
Published: December 2021

The work investigated the possibility of forming carbide coatings by electrospark alloying on steel products of complex shape. It has been established that electrospark alloying at an AC current of 1.0 to 4.5 A makes it possible to form coatings of hard carbide alloy VK6 and T15K6 characterized by microhardness up to 11.5 GPa and by hardness HRA 86.6 and 81.5 with the nitial hardness of the steel product HRA 80.3.
Dependence of field-effect biosensor sensitivity on photo-induced processes in Si and its conductivity type
Authors: Kozlowski A V , Stetsyura S V
Published: December 2021

The effect of photoelectron processes in n-Si and p-Si on the glucose sensitivity of a capacitive field-effect biosensor based on electrolyte/oxide/semiconductor structure was investigated. We obtained that illumination of n-Si/SiO2/PEI structure during the GOx adsorption increases the glucose sensitivity by three times compare to GOx adsorption in the dark. In contrast, p-Si illumination during the GOx adsorption led to a decrease in sensor sensitivity from 2.9 mV/mM to 2.2 mV/mM. The result is explained by a change in the density of immobilized GOx molecules due to a change in the electrostatic forces of attraction under illumination and stabilization of the photo-generated charge on the surface electronic states of the Si/SiO2 and SiO2/PEI interfaces after illumination.
Study of Langmuir monolayers and Langmuir-Schaefer films based on symmetrical meso-aryl-substituted porphyrin derivative
Authors: Mironyuk V N , Al-Alwani A J K , Begletsova N N , Gavrikov M V , Kolesnikova A S , Pozharov M V , Glukhovskoy E G
Published: December 2021

This paper presents the results of a study of meso-aryl-substituted porphyrin Langmuir monolayers by the method of compression isotherms. Experimental data were used to plot the dependences of the compression modulus (C−1) on the specific area. Monolayers at specific surface pressure were transferred to solid substrates and investigated. The monolayers were transferred to the surface of monocrystalline silicon at surface pressures of 8, 25, and 60 mN/m and examined them by atomic force microscopy (AFM) in a semi-contact mode. It was found that with an increase in the transfer pressure, the coarsening of molecular aggregates occurs. The smallest roughness is observed for a porphyrin film formed and transferred at a pressure of 8 mN/m.
Optimizing self-rotating bristle-bots for active matter implementation with robotic swarms
Authors: Porvatov V A , Rozenblit A D , Dmitriev A A , Burmistrov O I , Petrova D A , Gritsenko G Yu , Puhtina E M , Kretov E I , Filonov D S , Souslov A , Olekhno N A
Published: December 2021

Robotic swarms have been recently explored as a versatile and scalable alternative to traditional microscale platforms for experimental studies of active matter. These robotic setups consist of either self-propelled or self-rotating particles. In the present paper, we develop and experimentally realize a swarm of self-rotating bristle-bots suitable for a wide range of active-matter experiments. We focus on optimizing the bristle-bot design and controlling the sliding friction between individual robots.
Structural, morphological and catalytic characteristics of nanostructured palladium catalysts
Authors: Pushankina P D , Lutsenko I S , Glazkova I S , Malkov T I , Mukhanov M A
Published: December 2021

A new method for the highly active palladium catalyst synthesis on the surface of a Pd-23%Ag film has been developed to increase the material activity with respect to reactions involving hydrogen. Comparison of the electrochemical experiments data of classical palladium black and a new developed nanocatalyst demonstrated a significant increase in catalytic activity in the methanol oxidation reaction (up to 17.09 μA cm−2) for electrodes modified with the latter catalyst. The reason for that is an increase in the number of localized potentially more active surface regions due to the creation of a larger number of active sites in comparison with spherical particles. Estimation of resistance to CO poisoning showed high efficiency of nanocatalysts. Chronoamperometric experiment established the long-term stability and activity of the developed catalyst and confirmed the possibility of its practical use.
Fabrication of probe tips via the FIB method for nanodiagnostics of the surface of solids by atomic force microscopy
Authors: Rodriguez D J , Kotosonova A V , Ballouk H A , Shandyba N A , Osotova O I , Kolomiytsev A S
Published: December 2021

In this work, we carried out an investigation of commercial atomic force microscope (AFM) probes for contact and semi-contact modes, which were modified by focused ion beam (FIB). This method was used to modify the original tip shape of silicon AFM probes, by ion-etching and ion-enhance gas deposition. we show a better performance of the FIB-modified probes in contrast with the non-modified commercial probes. These results were obtained after using both probes in semi-contact mode in a calibration grating sample.
Research Of Dynamic Characteristics Of A Three-axis Micromechanical Gyroscope-Accelerometer
Authors: Lysenko I E , Sevostyanov D Y , Kidyaev N F , Kovalev A V
Published: December 2021

In this paper, an original design of a micromechanical gyroscope-accelerometer is proposed. A parametrizable geometric and finite element model of a micromechanical device is presented. The dynamic characteristics of the structure are studied and the dependences of the natural oscillation frequencies on the geometric parameters of the gyroscope-accelerometer are obtained.
Entanglement of two dipole-coupled qubits induced by a thermal field of one-mode lossless cavity with Kerr medium
Authors: Zakharov R K , Bashkirov E K
Published: December 2021

We studied the dynamics of two qubits interacting with one-mode thermal quantum electromagnetic field of microwave cavity with Kerr medium. Using the exact solution for considered model we derived the qubit-qubit negativity for separa coherent initial qubits states. We showed that initial qubits coherencee interaction can greatly enhance the degree of qubits entanglement in the presence of the Kerr nonlinearity and dipole-dipole interactionyeven for high thermal field intensities.
Analysis of Welding Position and Current on Mechanical Properties of A36 Steel using Shield Metal Arc Welding
Authors: Vietanti F , Rajan A F , Arifin A A , Feryanto D H , Suheni  , Irawan H , Ulum M , Arif R Z , Dicky M A , Darmawan F B
Published: December 2021

Welding is an assembly process that is most often used in the world of construction today. Welding is often used for repairing and maintenance of all tools made of metal, both as a process for filling cracks, temporary joining, or cutting metal parts. This study aims to determine the effect of welding current and position on the tensile strength and Vickers hardness (HV). This study uses ASTM A36 steel plate as base material. The variation of welding currents used are 90A, 110A, and 130A combine with variations in positions 1G, 2G, and 3G. The electrode used in this study is E6013 electrode with a diameter of 3.2 with a butt joint connection. All of processes are performed in room temperature with a strict condition. The results are as follow, the highest Ultimate Tensile Strength is obtained at 90A current and 3G position with a value of 471.93 MPa. For the highest hardness in the Vickers test, it is also obtained at 90A current and 3G position with a value of 242.20 Kgf/mm2.
Study of Catamaran Fishing Vessel Based on Solar Energy
Authors: Santosa P I , Pranatal E
Published: December 2021

Projected temperature that will be felt by world community will increase 7.5°C hotter in 2070, meaning that world community is threatened to live in extreme temperatures an average of 34°C in next 50 years. This prediction can occur if a reduction in greenhouse gas emissions fails to be carried out simultaneously. On or hand, impact of soaring crude oil prices on world market has been felt by all walks of life so it is necessary to create alternative solutions to dependence of fuel to get through difficult times. In sea transportation sector, use of fuel for motorized ships is not only uneconomical but also not environmentally friendly. Dependence on fossil fuel energy has led to development of energy-efficient ship concepts that use alternative energy sources in moving ships. This is anticipated by use of solar energy in form of Electricalboats (Eb) which are applied as fishing vessels. This paper presents a study of efficient use of solar energy in Eb as a boat driver that does not utilize fuel for development of environmentally friendly fishing vessels. Technical analysis is done through testing ship model in Towing Tank n results are explored with Naval Architect ories. In conclusion, there is a potential for fuel consumption savings of up to 90% when compared to ships that only use conventional engines.
Scheduling for Prosumer Microgrid with Considering Price Based Demand Response
Authors: Suheta T , Penangsang O , Ashari M , Delfianti R
Published: December 2021

Unit commitment (UC) is the scheduling of power unit operating outages to meet electricity needs at a certain time with the aim of obtaining a total economical generating cost. Differences in the characteristics of each generating unit and limitations result in different scheduling combinations based on equations, and for this research, the renewable energy penetration will also be considered. Firefly Algorithm (FA) is a method to determine load requests and complete renewable energy scheduling power by using unit commitment. FA is a simple but reliable algorithm that solves optimization problems. Firefly Algorithm (FA) method obtained maximum generating power of 81,329 MW with the total cost of 827,556 $ and network losses of 3.6696 Coefficient of operating costs.
Promising Potential of Eugenol (Clove) Based Organic Membrane for Polymer Electrolyte Membrane Fuel Cell
Authors: Muliawati E C , Budianto A , Hamid A
Published: December 2021

Fuel cell is one of alternative method to replace fossil fuel energy. The important component of fuel cell is a membrane that used for separating cathode and anode also as a proton conductor. The purpose of this research is to produce polymer electrolyte membrane from poly (eugenol sulfonate) (PES) as polymer matrix, characterize the resulting membrane analysis using ionic properties analysis by calculating ionic conductivity using impedance spectroscopy, ion exchange capacity (IEC), solvent absorption analysis by calculating water uptake and methanol permeability, and studying mechanism Proton transport that occurs on the membrane. This research was initiated by making polymer of PES, and then fabrication and characterization of electrolytic polymer membrane. The formed membrane has an optimal proton conductivity of 0.00095 S.cm-1 with PES composition of 22% (wt).
Activated Carbon Producing from Young Coconut Coir and Shells to Meet Activated Carbon Needs in Water Purification Process
Authors: Budianto A , Kusdarini E , Mangkurat W , Nurdiana E , Asri N P
Published: December 2021

Young Coconut products have many benefits for society as for drinks and medicine, and it produces young Coconut shells and coir waste. The contents of cellulose and carbon elements are interesting to be utilized to be activated carbon. This research aimed to know the activator concentration of hydroxide potassium chemical and heating physical with microwave electrical power to produce activated carbon products. This research was conducted in laboratory experiments with chemical and physical activation methods, measuring proximate and iodine product numbers. The result showed that activated carbon from young Coconuts shells and coir with activation process used chemical activation and produced activated carbon products that met SNI standard number 06-3730-1995. Iodine number of activated carbons was in the range of 1776.60 mg/g – 2220.75 mg/g, iodine number as more than 23.5% of SNI Standard.
Study of integral and differential strength and deformation characteristics of centrifuged and vibrating centrifuged concrete on activated Portland cement
Authors: Mailyan L R , Stel’makh S A , Shcherban’ E M , Chernykh D S
Published: December 2021

In this work, the study of integral and differential strength and deformation characteristics of centrifuged and vibrating centrifuged concrete on activated Portland cement was carried out. Mechanical activation of cement was carried out using a specialized grinding unit. Manufacturing of centrifuged and vibrating centrifuged samples was carried out on an experimental laboratory centrifuge. All samples were made of concrete of the same composition. The optimum values of technological parameters of centrifugation and vibrating centrifugation are given. The scheme of obtaining small-size specimens from a common annular section to determine the strength and strain characteristics was developed. According to the results of the study it was found that the improvement of integral and differential strength and strain characteristics when using activated Portland cement is observed for both centrifuged and vibrating centrifuged specimens. However, the samples made by vibrating centrifugation technology have better strength and strain characteristics than the samples made by centrifugation. According to the results of the study, it was found that the activation of Portland cement at its rational values is the best way to enhance variatropy.
Physical and mechanical properties of the surface of pine wood modified with an organomineral composition
Authors: Belyaev A O , Danilov V E , Morozova M V
Published: December 2021

The percentage of wooden buildings damaged or even lost due to the lack or insufficient technical measures for their preservation is growing every year. This fact makes it mandatory to treat the surface of wood building materials with protective and decorative agents. Within the framework of this study, a multifunctional protective composition for wood was developed that can increase its physical and mechanical properties. Modification of the wood surface with organomineral compositions leads to an increase in its density, hardness and strength. The hardness of the treated wood is 24% higher and the compressive strength along the fiber is 20% higher than that of untreated wood. After treatment, the surface of the wood darkened and slightly yellowed, which does not prevent its use in the construction and reconstruction of buildings. The results of measuring the color coordinates of the surface of the modified samples indicate the stability and durability of the developed protective coating even after 4 months of exposure to atmospheric conditions. Judging by the slight return of the color coordinates of the treated wood back to values of the original wood, it can be concluded that the composition is partially washed out.
Dynamics and criteria of CFRP destruction by lightning currents
Authors: Guschin I A
Published: December 2021

The article discusses a promising conductive composite material such as carbon-plastic. This material has significant strength, not inferior to metal, has a low specific weight and has interesting electrophysical characteristics. For a wider use of the material in various structural products, it is necessary to consider its unique characteristics. The work is devoted to the study of the conductive properties of carbon fiber under the influence of lightning currents and the development of criteria for its destruction. Based on two models of destruction of CFRP by lightning currents, a theoretical analysis of its destruction has been carried out. The first model considered the composite material as a continuous medium with anisotropic-conducting properties. The solution of the Laplace equation with the Neumann boundary conditions made it possible to find the distribution of current densities over the material and theoretically determine the radius and depth of damage. The second model, the layered structure model, took into account the structure of real CFRP. The dynamics of layer-by-layer destruction is considered on the basis of the equivalent circuit of carbon fiber reinforced plastic, which takes into account the longitudinal and transverse resistivity of the composite. The distributions of the radial current density along the radius and depth of the material are constructed and the analysis of the spreading of currents at various degrees of material anisotropy is carried out. Strong anisotropy, leading to the release of total energy in the first layer. Destruction of the upper layer changes the distribution of currents in the rest of the layers. The results of numerical modeling of layer-by-layer destruction of CFRP for five layers are presented. The process of destruction under the action of large current pulses is considered. The fracture criteria for various degrees of material anisotropy are obtained and refined. The resulting formulas contain values that are reproduced in the experiment. The calculation results are in good agreement with experiment. In conclusion, it is concluded that the criteria are applied to predict the effects of lightning and optimize lightning protection at the design stage of an aircraft.
Analysis of the effect of ionizing radiation on the properties of bulk nonwoven material
Authors: Lisanevich M S , Yu Galimzyanova R , Ivanov V V
Published: December 2021

At the moment, there is a wide range of bulky nonwovens for various purposes on the market. One of the important areas of using such materials is healthcare. In particular, bulky nonwoven materials are intended for the manufacture of wound dressings, evacuation kits for newborns. Disposable medical devices of this kind are usually subjected to radiation sterilization. As is known from earlier studies, radiation sterilization significantly affects the performance of nonwovens. In this regard, for nonwoven materials for medical use, an important characteristic is the stability of indicators after exposure to radiation sterilization. As a result of the study of bulk nonwovens Holofiber ® after radiation radiation in the dose range from 20-60 kGy, there were no significant changes in operational performance. The stiffness increased by an average of 3-10%. The stiffness indicators after ionizing radiation according to GOST 24684 also meet the requirements. The value of electrification increased due to an increase in the static field under the action of ionizing radiation. It is worth noting that the values of electrification are within the norm established by GOST 32995. The breaking load varies from 1-5%. Thus, non-woven materials Holofiber ® PROFI, article P 35191, Holofiber ® SOFT, article P 5197, Holofiber ® SOFT, article P 5200 are recommended for the production of medical devices.
Preparation of Energetic Composites Materials via Sol-Gel
Authors: Guo Baoqiong , Wei Xiaoan , Wang Binbin
Published: December 2021

In this research, nitrocellulose / magnesium borohydride nanomaterials (NC / Mg(BHx)y) nanoenergetic composite materials are synthesized through sol-gel method and the freeze-drying technology. Among them, nitrocellulose (NC) is used as a gel matrix to load Mg(BHx)y particles. Scanning electron microscopy (SEM) results show that Mg(BHx)y is embedded and uniformly dispersed in the NC matrix. The particle size of the high-energy composite material is about 2 μm. The results of FT-IR showed that the hydrogen storage alloy was successfully loaded around the NC without destroying the cellulose structure. The composite material decomposition reaction (Temperature-Time) curve is obtained through the adiabatic accelerated calorimeter (ES-ARC) test.
Synthesis and Applications of Functional Nanomaterials
Authors: Li Yujia , Xia Hanzheng , Xu Jingyi
Published: December 2021

The unique physical and chemical properties and variable application potential of nanomaterials are continuously devoted to stimulating scientists’ studying enthusiasm. Extremely fine grains bring quantities excellent properties such as low density, low elastic modulus, high resistance and low thermal conductivity to nanomaterials, which has extensive use in the photoelectric field, environment, bioengineering and other fields. The research progress of graphene quantum dots, transparent reflective coatings and self-assembled nanotubes are mainly demonstrated. This paper shows the role of graphene quantum dots in solar cells, summarizes the synthesis methods of self-assembled nanotubes and their applications in bioengineering, and describes the development of transparent thermal reflective coatings for energy-saving glass attributed to providing relevant reference and basis for the development and research of nanomaterials.
The study on polycarboxylate superplasticizer with polyamine side chain using molecular dynamics simulation
Authors: Lin Xiaochen , Chuang Pohsiang , Fang Yunhui
Published: December 2021

A new type of water-reducing agent, which contains polyamine side chains, has been theoretically studied utilizing molecular dynamics simulation (MD) in this research. The models of three types of water reducers in an aqueous solution, including SNF, PCE, and PCA, have been constructed, simulated, and analyzed. The results indicate that compared to the linear structure of SNF, the traditional PCE water-reducing agent has a stronger interaction with water molecules, so it has a better water-reducing effect. This stronger interaction is mainly provided by the side chain of PCE. PCA further enhances the hydrophilicity of its side chain based on PCE structure, leading to a stronger interaction on water molecules than traditional PCE molecules. The migration ability of water-reducing agents and other molecules in the system has been further explored. The diffusion coefficient of three water reducer molecules decreases in the following order: PCE>SNF>PCA. This is due to the interaction between molecules, especially the incompatible strength and quantity of hydrogen bonding.
Study on process mineralogy of limonite
Authors: Yang Jinlin , Xu Shuo , Zhu Pengyan , Ma Shaojian
Published: December 2021

In this paper, the process mineralogy, such as the composition and content of elements and minerals, and the chemical composition of main minerals, was studied by the method of mineral liberation analyser. The results show that the ore is limonite bearing-zinc ore, the content of the main mineral limonite is 95.982%, most of limonite is monomeric, a few limonite is associated with pyrite and muscovite, with quartz, with sericite and quartz, limonite contains sericite, synbiote of limonite and sericite. Zinc occurs mainly in limonite, a small amount of zinc in the form of sphalerite, smithsonite and hemimorphite. This study will lay a mineralogical foundation for the follow-up development and utilization of this type of ore.
Phase Transformation Kinetics of High Nb-TiAl Alloy during Continuous Heating
Authors: Li Ying , Zhou Lian , Lin Junpin , Chang Hui , Fan Jianglei , Cao Yang , Wang Yan , Wang Yongbiao , Liu Jianxiu
Published: December 2021

In this work, the phase transformation behavior of Ti-45Al-8.5Nb-(W, B, Y) alloy during continuous heating was investigated using dilatometer and optical microscopy. Results indicated that the phase transformation process of high Nb-TiAl alloy during continuous heating included two stages: ordered α2 → disorder α and tetragonal γ → hexagonal α. According to the microstructure analysis, the initial α2/γ lamellar structure transformed into the massive γ phase and α phase (retained as α2) during the heating process. The activation energy of α2 → α and γ → α was 989.65 kJ/mol and 995.30 kJ/mol, respectively. Moreover, the lower the heating rate was, the faster the phase transformation reached the equilibrium state.
Numerical Simulation and Microstructure and Properties of 45 Steel by Scanning Electron Beam Bevel Polishing
Authors: Xia Tenghui , Du Chunping , Liu Zhiyong , Lu Jian , Zhu Zhifa
Published: December 2021

In order to obtain metal products with good surface quality, it is necessary to develop an efficient bevel polishing method. Therefore, this article Uses continuous scanning electron beam polishing. The surface of the material undergoes rapid melting and solidification and generates a dynamic temperature field. The polishing treatment improves the microstructure of the surface layer of the quenched and tempered 45 steel, and significantly increases the microhardness of the surface layer. The hardness after treatment can reach up to 747.6Hv, which is about 2.4 times higher than the matrix; the structure after hardening is transformed from the mixed phase of coarse acicular martensite and lath martensite to hidden acicular martensite and retained austenite a mixed phase thereof. In addition, after bevels with different inclination angles are subjected to electron beam surface polishing modification treatments with different scanning speeds, under the same parameters, as the inclination angle increases, the hardness value at the same position decreases.
Research on Dynamics Stiffness of Honeycomb Sandwich Structure Door
Authors: Yuan Xiuqi
Published: December 2021

During the emergency opening of the aircraft door in the air, the door must experience a complex and harsh mechanical environment. In order to ensure the high reliability of the door, it must have sufficient dynamic stiffness. When using finite element software for static engineering analysis, the calculation results often have large deviations due to improper simplification of the motion links in the structure. Aiming at the characteristics of the honeycomb sandwich structure of a class of civil aircraft doors, a combination of topology optimization and dynamic analysis was adopted to take into account the door load and the door opening speed. The results of dynamic calculation show that when the door is opened in the air, the bending deformation during cruise is in compliance with the requirements, and the structural rigidity meets the functional requirements. The research results have important effects on the design and optimization of the stiffness performance of honeycomb sandwich doors.
A setup to characterize the tensile mechanical properties of poly(L-lactic acid) materials applied in bioresorbable polymer stents
Authors: Zhao G. , He R. , Li X. , Zhang J. , Cheng J. , Wu G. , Ni Z.
Published: December 2021

A method for testing mechanical properties of miniature
poly(L-lactic acid)(PLLA) specimens is instrumented and set up in
this research. This method is specially designed to measure
mechanical properties, including elasticity modulus, yield strength
and breaking elongation, of miniature PLLA specimens in three
different shapes at various tensile speeds and
temperatures. Moreover, the measurement results are significantly
dependent on the tensile speeds and temperatures. This phenomenon
further verifies the obvious existence of the viscoelasticity of
PLLA. Finally, it can be concluded that, with this method,
mechanical properties of PLLA can be better investigated and
understood, especially for PLLA used for biodegradable polymer
stents.
Performance Monitoring of the Barrel Time-of-Flight Supermodule for the PANDA Experiment at FAIR
Authors: Chesnevskaya S. , Zimmermann S. , Zmeskal J.
Published: December 2021

The PANDA experiment at FAIR in Darmstadt will use
proton-antiproton collisions, with momenta ranging from 1.5 GeV/c
to 15 GeV/c, on a fixed target to study open questions in hadron
physics. The Barrel Time-of-Flight detector for this experiment is a
scintillating tile hodoscope based on 16 identical and independent
subdetectors called Super-Modules arranged in a cylindrical
configuration. We have conducted performance studies on one such
Super-Module to prove the feasibility of the Barrel Time-of-Flight
detector design. Time resolution, signal delay and amplitude drop
along the length of the detector were measured and analyzed as a
function of the position on the individual scintillator tiles. A
time resolution of about 50 ps has been achieved, which is very
important for event timing and particle identification.
Calculation of Pore Throat Radius Percentiles (25, 50 & 75) From Porosity and/or Permeability: Algyo Oil and Gas Field, Hungary
Authors: Sayed Nahla A. El , Abdel Moktader A. El sayed
Published: December 2021

Pore throat size distribution of reservoir rocks has a great importance in hydrocarbon migration and entrapment. It is used for study permeability barriers, reservoir characterization and stratigraphic traps. In the present study 51 core samples obtained from Algyo oil and gas field were conducted to MICP laboratory technique to study pore throat size distribution. The inclusive graphical measures of gain size analysis were borrowed for pore throat size examination. Various pore throat radius percentiles such as 25,50 and 75 were calculated and related to both rock porosity and permeability. The obtained models were robust and reliable to use for pore throat radius percentiles (25,50 and 75) calculation. One of these models which is predicting the 50 percentiles was verified. It shows reliable coefficients of correlation (R2 = 0.77 and 0.79) as it is estimated from permeability and porosity, respectively.
Implementation of the 2030 sustainable development goals - affordable and clean energy in the European Union
Authors: Rybak Aurelia , Wlodarczyk Ewelina
Published: December 2021

One of the most important goals of the European Union is to provide citizens of the Member States security and stability in fuel and electricity sectors. The United Nations has defined 17 goals and 169 actions to achieve sustainable development of the world. The goals were to improve the quality of life, reduce the level of poverty, inequalities in the world and sustainable development in terms of climate and environmental protection. The article presents an analysis of the implementation of one of the assumed goals, i.e., sustainable development in the field of Affordable and clean Energy in the European Union. This goal is to ensure that every citizen has access to stable, sustainable, and modern energy at an affordable price. Among others, indicators such as energy import dependency, energy productivity, share of renewable energy in gross final energy consumption, final energy consumption in households per capita were analysed. The authors analysed the trends of the above-mentioned indicators in the European Union, with particular emphasis on Poland. In order to be able to predict how the analysed phenomena will develop until 2030, the authors built forecasts. For this purpose, among others, ARIMA models were used. The authors created several dozen models, from among which model with the smallest ex post errors and the lowest value of information criteria were selected. The models allowed to determine the degree of achievement of the set goals. They also allowed the designation of scenarios for the potential development of the analysed indicators.
Paleontological monument of nature “Mamontova Gora” exposure (Yakutia, Eastern Siberia, Russia)
Authors: Boeskorov Gennady , Shchelchkova Marina
Published: December 2021

The Mamontova Gora (“Mammoth Mountain”) exposure is the Neogene – Pleistocene key section of Siberia. This outcrop is located in the lower reaches of the Aldan River, 325 km above its mouth and extends for almost 12 km. It consists of an 80-meter structural plateau (80-meter terrace), 50- and 30-meter alluvial terraces. Sediments from the Middle Miocene (16-10 Ma) to the Upper Pleistocene are exposed on the 80-meter terrace. The basement of the 50-meter terrace is composed of Middle Miocene sediments, overlain by Pleistocene sediments. On a younger 30 m terrace, the deposits are dated from the Upper Pliocene to the Upper Pleistocene. The Mamontova Gora outcrop is one of the richest localities of the Neogene flora of Eurasia. There are numerous finds of remains of Miocene evergreen and thermophilic plants (tree stumps, leaf imprints, cones, nuts, seeds). More than 250 genera of fossil plants have been found on Mamontova Gora. This outcrop is also well known to paleontologists due to the abundance of bone remains of mammals of the Middle Pleistocene (early type mammoth, eastern horse, broad-fronted moose, long-horned bison) and Late Pleistocene (representatives of the mammoth fauna: woolly mammoth, woolly rhinoceros, Lena horse, reindeer, saiga-antelope, steppe bison, Arctic fox, wolverine, cave lion, etc.). It was revealed that the ancient frozen sediments on the Mamontova Gora outcrop abound with viable microorganisms and traces of their vital activity. A strain of microbe Bacillus sp. was isolated from ~ 2 - 3 Ma permafrost layers of this outcrop. A large group of microorganisms including fungi was isolated from the ancient ice wedge. Pleistocene permafrost deposits contain invertase, urease, catalase and dehydrogenase enzimes. Mamontova Gora is a unique geological object in Russia. By the decree of the Council of Ministers of the Yakutia Autonomous Soviet Socialist Republic of 18.02.1987 No. 56 Mamontova Gora was given the status of a “natural monument” and a specially protected natural area of regional significance. The article presents the main results of studies of ancient flora and faunas of Mamontova Gora.
The Effect of a Rubber Sheet on the Dynamic Response of a Machine Foundation Located over a Small Thickness of Soil Layer
Authors: Khalaj Omid , Zakeri Reza , Tafreshi Seyed Naser Moghaddas , Mašek Bohuslav , Štadler Ctibor
Published: December 2021

Placing a machine footing over a small thickness of soil layer, which is located over a bedrock, could encounter many challenges due to the bed’s notable stiffness in comparison to the soil. The advantages of using rubbers to protect facilities (structures, machine foundations, nearby footings and equipment, etc.) from vibration and control its consequences are well known nowadays. In this study, the benefits of employing a small thickness of rubber sheet (2 mm) on the dynamic response of a machine foundation which is located over four thicknesses of soil (210, 420, 630, and 840 mm) has been investigated. The soil layer is located over an artificial bedrock that is consisted of a thick concrete layer. The tests have been conducted in a vast test pit of size 2500×2500 mm and a depth of 840 mm by using a semi large-scale machine foundation model with a square concrete foundation of width 400×400×100 mm. It was observed that, by increasing the soil layer thickness, the resonant frequency and amplitude of the vibrating system decreases. Moreover, by employing a rubber sheet beneath the machine footing, the resonant frequency of the vibrating system significantly decreases especially for a small thickness of the soil layer. Although, using a rubber sheet could slightly increase the resonant amplitude, but the benefit of the resonant frequency-changing capability of the rubber sheet is too impressive by taking the resonant frequency of the system far enough from the unchangeable working frequency of the machine and preventing the resonant phenomenon to happen.
The Experimental Investigation of the Repeated-Loading Behaviour of the Sand-Rubber-Mixture (SRM)
Authors: Khalaj Omid , Zakeri Reza , Tafreshi Seyed Naser Moghaddas , Mašek Bohuslav , štadler Ctibor
Published: December 2021

Nowadays the waste rubber problems are concerned due to the environmental issues, storage, and recycling difficulty. However, the rubber base equipment has been widely used to protect structures for vibrations - that has been generated by the structure or induced from the vicinity area or the bedrock into the structure - due to the notable capability of absorbing energy. In this study, the repeated-loading behaviour of the Sand Rubber Mixture (SRM) has been investigated and the remarkable energy absorption properties of the mixture have been illustrated. The test soil material that has been used in this study was a well-graded sand (SW) with a mean grain size of 2 mm. The test martial rubber that has been used was grain particles with a uniform size of 4.76 mm. The sand rubber mixture (SRM) was prepared by using 7.5% rubber inclusion because it was found as the optimum rubber content. A series of force control repeated-loading CBR tests have been arranged. The effect of mixing rubber particles with the well-graded sand (SW test material) has been investigated. This shows the remarkable energy absorption capability of Sand Rubber Mixture (SRM) to protect the bed of a machine’s footing that is generating repeated loads. The SRM usage could be extended to be employed as a part of an energy absorption unit and dampers facilities beneath a machine footing or structures that are sensitive to the vibration to prevent destructive deformation and resonance phenomenon.
Defining of the required parameters of the main fans on the ventilation shaft for the target model of the hard coal mine Y in connection with its decommissioning
Authors: Mocek Piotr
Published: December 2021

The article presents the results of the analysis and calculations of the ventilation network of the decommissioned hard coal mine Y for the model of its target operation. After the end of hard coal mining and the liquidation of most of the mining excavations, the former Y hard coal mine will become an element of the drainage system and a protection for other, still active mining plants. In order for the Y excavation to be transformed into a mine water pumping station, its ventilation system should be rebuilt, and new parameters of the main fan should be determined for a smaller network of mining excavations. For this purpose, using the AERO-2016D program by POK “Zachód” Spółka z o.o., the parameters of the ventilation network were simulated in the target model of mine Y after the liquidation of the “Southern” shaft and mining excavations at levels 530m and 660m. The results of the simulation made it possible to select the optimal main fans for the target model of the transformed mine Y.
Experimental Investigation of Influences of Traffic Load on the Church of the Assumption of the Virgin Mary in Stará Boleslav
Authors: Bayer Jan , Urushadze Shota , Pirner Miroš
Published: December 2021

Long-term dynamic loads represent a serious factor which compromise the safety and durability of historical buildings. Though the daily traffic may cause only low level vibrations, which an undamaged structure could safely resist, extreme values of traffic loads over longer periods can be critical having as a consequence the initiation of cracks or the growth of existing ones, such that they may endanger the structure. Good maintenance including control measurements or monitoring can aid in early damage detection and timely planning of remedial actions. The preceding statements are supported by an investigation of the effects of ambient vibrations mainly due to traffic loads on the Basilica of the Assumption of the Virgin Mary in Stará Boleslav. Attention is aimed at a structural fault, its rehabilitation and prognosis for the future.
Removal of Specific Pharmaceuticals from Water using Activated Carbon
Authors: Ilavský Ján , Barloková Danka , Marton Michal
Published: December 2021

Many types of pharmaceutical substances have been detected with significant concentrations through various advanced instrumental techniques in surface water, ground water, partially treated water (with concentration typically less than 0,1 ug/L), drinking water (concentration bellow 0,05 ug/L) domestic wastewater, municipal wastewater and industrial effluents (concentration approximately 1 ug/L). Pharmaceutical compounds are found at much lower concentrations in drinking water sources then the normally prescribed doses, but there is concern that chronic exposure to numerous compounds could cause serious health problems and that compounds can act synergistically to cause adverse health effects. The effectiveness of removal the specific pharmaceuticals (paracetamol, carbamazepine, metronidazole and caffeine) from drinking water with adsorption using two types of granular activated carbon (Filtrasorb 400 and WG12) was monitored. Paracetamol is a medication used to treat fever and mild to moderate pain. Paracetamol significantly relieves pain in acute migraine and headache. Carbamazepine is an anticonvulsant medication used primarily in the treatment of epilepsy and neuropathic pain. It is used in schizophrenia along with other medications and as a second-line agent in bipolar disorder. Metronidazole is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat inflammatory disease. Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is the world’s most widely consumed psychoactive drug. The concentrations of caffeine in surface waters were detected in the range 0.1 - 6.9 μg/L. The experiments were performed in laboratory conditions with varying values of pH (7,8 or 6,5), stable temperature, and dose of adsorbent. The experiments were performed in the glass bottles with the volume of 400 mL stock model water (drinking water spiked with pharmaceutical standard) with concentration approximately 0.05 μg/L. On the analytical scales weighed out 400 mg GAC was used and then it was added to the bottles. Subsequently these bottles were regularly stirred at 400 rpm. Samples were taken at 30, 60, 120 and 240 minutes, after which they were analyzed. Analyses of target pharmaceutical were performed in laboratories of ALS Czech Republic in Prague. LC-MS methodology (method was validated according to ISO 17025 system) was used to determine pharmaceuticals in water samples. The adsorption efficiency of pharmaceutical removal and the adsorption capacity of granular activated carbon depends on the time of contact of water with the material. Adsorption efficiency for two types of granular activated carbon varies from 13 to more than 90%.
Actual Satellite Imagery Sources
Authors: Izvoltova Jana , Kriauciunaite-Neklejonoviene Vilma , Sasik Robert
Published: December 2021

The huge benefit of the Internet is that it not only connects people from all over the world but also provides information that would otherwise be unavailable. Anyone who needs access to the latest satellite imagery can take it via many platforms provided remote sensing data, either for free from the websites belonging to national research and space centers or for a fee charged by commercial companies. The article offers an overview of the most used services, whose data are available and suitable for processing using EarthExplorer – a platform of the U.S. Geological Survey agency.
Quality of the Surface Water in the Ratka Small Water Reservoir
Authors: Sabová Zuzana
Published: December 2021

The aim of the contribution is to evaluate the state of the quality of the surface water in the Ratka small water reservoir and its surroundings. The Ratka small water reservoir is included in fishing grounds; it is therefore necessary to know the quality of the surface water. The work is focused on an evaluation of the surface water quality indicators, i.e., the water temperature, pH reaction, content of the nitrate nitrogen, nitrite nitrogen, and the ammonia nitrogen, the chemical oxygen demands, and the total organic carbon. The analysis was divided into field measurements and laboratory measurements. Three sampling points were identified, from which samples were regularly taken. For water temperature and pH reaction, the field measurements were performed every month during 2019 and for other selected indicators of water quality, the field measurements were performed during April – September 2019. The laboratory analyses were realized in 2019 (summer, winter) and were focused only on samples from the Ratka small water reservoir. To evaluate the results, they were compared with the recommended values found in the valid Regulation of the Government of the Slovak Republic No. 269/2010 Coll. After evaluating the results of the study, increased values indicators of quality of the surface water were found water temperature, pH reaction, N — NO2
, chemical oxygen demands and total organic carbon. Phosphate contents are also present in the water. The results showed that the Ratka small water reservoir, due to the increased values of the mentioned indicators of the quality of the surface water, does not meet the set conditions of the Government of the Slovak Republic. The significance of this study can be seen not only in the importance of water quality assessment from the practical point of view, but also in the need to perform these analyses, especially in areas where no water quality assessments have been performed so far, an example of which is the Ratka small water reservoir assessed in this study.