bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental study on influence of biofuels on injection characteristics of diesel engine common rail system
Authors: Slavinskas Stasys , Bendziunas Paulius
Published: July 2024

The presented work focuses on experimental analyses of the influence of biofuels on the injection characteristics of a common rail injection system. Mineral diesel fuel, neat biodiesel fuel made from rapeseed oil and hydrotreated vegetable oil are addressed. Attention is focused on the injection characteristics which significantly influence the engine characteristics and subsequently the exhaust emissions. The injection rate, and the cycle injection quantity are studied across a range of injection pressures and injector energising duration. The fuel injection rates were measured and analysed using an injection rate measuring system based on the Bosch method. The measurement concept is based on measuring the change in the pressure by the injection of fuel into a long measuring tube filled with fuel. This pressure change is proportional to the fuel injection rate. The tested biodiesel shows lower injection rates at the stable injection period in the volumetric injection rate curves, but the mass injection rates among all test fuels are quite close. Injection delay was longer by injection of biodiesel than by injection of other fuels tested. The injector energizing time significantly influences the shape of the injection rate curve. The actual injection duration in all cases exceeded the injector energising pulse duration. The results show that the fuel density is the main property that affects the injection process. Fuel viscosity also affects, but to a lesser extent, the injector mass flow rate since it changes the coefficient of friction.
Economic analysis of emergence of bipolar European Union, 2011-2022
Authors: Kaposzta Jozsef , Lorinc Balazs
Published: July 2024

Looking at the economies of the 27 Member States of the European Union, we see a significant degree of polarisation. These disparities are reflected in marked differences in the levels of social and economic development of the EU Member States. The enlargement process of recent decades has clearly reinforced these trends. Generally speaking, the economic performance of the less developed Member States (generally those that joined in 2004 or later) has moved closer to the EU average, but it can also be said that the NUTS 2 regions with the highest levels of underdevelopment are mainly located in these EU Member States, and thus tend to be further away from the EU average. On the basis of these results, we have analysed the bipolar economic development of the EU Member Countries. The aim of our study was to identify the links between employment rates and their changes and economic performance that would provide a comprehensive picture of the deep-rooted structural differences that are nowadays proving to be of crucial importance in the EU Member States. Our results show that employment trends in the EU Member Countries that joined in 2004 or later have caught up with the average of the pre-2004 Member States by 2022, but their economic performance has evolved at a much slower pace, and economic gaps between the two groups of countries have increased, contributing to the almost permanent differences in economic competitiveness between the two poles of Europe and between the groups of countries.
Greener last-mile delivery technologies and regional development in Latvia: input-output approach
Authors: Auzina-Emsina Astra
Published: July 2024

The European Green Deal targets to limit emissions by applying sustainable and greener technologies in transport, including last-mile delivery services. The aim is to estimate the potential impact of application of greener last-mile delivery technologies in the companies on sectoral and regional development in Latvia, using the input-output approach applying the latest data set of 2020 for Latvia. The economy is disaggregated according to the NACE 2-digit level into 64 economic activities and regional development additionally into 5 regions (Riga, Vidzeme, Kurzeme, Zemgale, and Latgale). The bottom-up approach is used. According to NACE, postal and courier services (H53) are selected as the main focus in the research reflecting last-mile delivery services. Sweden is used as a benchmark country as Sweden is already having one of the greenest transport sectors. Modelling results argue that if the postal and courier services in Latvia apply a greener technology that already exists (possible, achievable technology, not just in theory), then the total value added declines by -0.1% due to lower intermediate consumption for manufactured products. The most positive impact is on services (as warehouse services, employment services, wholesale trade services), however, the services auxiliary to financial services and insurance services, air transport services, paper and its products have the most negative impact. The modelled regional results claim that the major negative impact is in the metropolitan areas (Riga region), medium – Kurzeme and Latgale, minimal impact – Vidzeme and Zemgale. The findings are valuable to the companies in the industries that might be affected due to the shift towards other technologies and practices, as well as for the national government and EU institutions in policymaking.
Modelling of hazardous operating modes of rubber-cord coupling in fem environment
Authors: Gorbacovs Dmitrijs , Gavrilovs Pavels , Eiduks Janis
Published: July 2024

Relevance of the research topic. During operation rubber-cord couplings with a toroidal shell form may fail. For the period from 2019 to 2023 (5 years) such failures amounted to more than 58 cases. According to a visual inspection of a large number of failed rubber-cord couplings, it was found that the cause of failure was a rupture of the side surface. The aim of this scientific article is to determine the forces and moments acting on the rubber-cord coupling, as well as the displacements of the shafts connected by the rubber-cord coupling in axial, radial and angular deflections. To determine the properties of the material, single tensile and cyclic tests of fragments of rubber-cord couplings were carried out. Based on the test results, a mathematical model of the material was determined. In the environment of the FEM software, the test results were compared with models of elastomeric materials and the most suitable model of elastomeric material that most accurately corresponded to the test results was selected. The calculated forces and torque effects were simulated, and the effects of radial, axial and angular deflection and measured coupling deflections were simulated. The purpose of modelling is to identify dangerous operating modes and dangerous forms of the rubber-cord coupling loading during operation.
War influence on sunflower seed and oil production in Ukraine
Authors: Petrenko Vasyl , Naumenko Oksana , Nechai Oksana , Bondar Valeria
Published: July 2024

Sunflower is a high oil content seed and average yields can produce 600 pounds of oil per acre, considerably more than soybeans and some other oilseeds. There is a great deal of interest from EU market for construction of small processing facilities for sunflower biodiesel production. For more than 10 years Ukraine is known as the biggest producer of sunflower seeds worldwide. For now, sunflower seeds and oil are the most profitable branch of agricultural production in Ukraine, which has a steady demand from global farmers. Moreover, among the agrarian activities of oil crops, the segment of sunflower cultivation and processing suffered the biggest blow from military operations, since the sown areas under sunflower make up an average of 62% of the entire area of oil crops in Ukraine. The ecological consequences of hostilities for the environment are accompanied by significant destruction of natural ecosystems and environmental pollution. Each rocket or projectile explosion pollutes the air, water and soil with toxic substances. Many industrial facilities were attacked, resulting in uncontrolled emissions of pollutants. Military operations and related activities led to a significant number of violations of the natural environment and established forms of agricultural use of nature. The purpose of this study is to analyse in which way the cultivation of sunflower seeds and producing of sunflower seed oil has changed since the war in Ukraine started from February 24, 2022.
Influence of road user behavior on occurrence of accident: agricultural vehicles and motorcyclists
Authors: Ballay Michal , Macurova Ludmila , Kohut Pavol , Redl Miroslav
Published: July 2024

The heightened presence of agricultural vehicles on roads is driven by the seasonal nature of agricultural operations. These vehicles are typically wider, heavier and slower than other road vehicles, significantly impacting the traffic flow and posing a safety concern. While accidents involving agricultural vehicles are less frequent compared to those involving other road vehicles, their severity is often far greater. In the event of a collision between an agricultural vehicle and one of the most vulnerable road users, the consequences can be particularly severe. If they collide with each other, there is a much higher probability of serious injuries (given their nature and extent), very often with fatal consequences. The most common causes of these traffic collisions include the risky behaviour of road users, disregard for road traffic rules, mental and physical fatigue, vehicle breakdowns, etc. Critical sections where various traffic collisions occur the most are intersections, exits from a side road to the main road or vice versa, wrong turning from the main road to a side road, confusing turns. The paper deals with the analysis of a specific traffic accident involving an agricultural vehicle with a trailer (Zetor Forterra tractor) and motorcycles. This traffic accident was located in the outskirts of the village, on a straight section of the road, on a slight incline, where the maximum speed of 90 kilometers per hour was allowed. The emergence and course of the accident scene is investigated with regard to the specificities of the movement of road traffic participants on roads. As part of the analysis, the speed of the vehicles before the collision, the impact speed with regard to the drivers’ vision, the driving technique of the drivers was calculated and evaluated, and the technical cause of the accident event was established. At the end, the possibilities of averting an accident on the part of individual road traffic participants are described.
Neutron shielding material containing basalt-boron fibers and OSA for spent nuclear fuel container, numerical modelling
Authors: Romanenko Iryna , Novakova Iveta , Motlep Riho , Gulik Volodymyr , Krasnikovs Andrejs , Vaisnoras Mindaugas
Published: July 2024

Nuclear power plants and research purposed reactors produce spent nuclear fuel, which leads to a need for safe spent fuel management and radiation protection. Traditionally, concrete with the addition of different aggregates has been the primary material for shielding against radiation and is used also for transport and storage of radioactive waste. Despite these applications, there is still a need to develop new composite materials that will preserve the radiation shielding properties of concrete, while offering superior mechanical and also cost effective benefits. This article investigates the radiation shielding properties of HI-STORM containers, made of a new composite material, and reinforced with basalt-boron fibre for human and environment protection. In the concrete recipe, part of the cement is replaced by oil shale ash with cementitious characteristics. The formulation of concrete reinforced with basalt-boron fibre (with the addition of 6% boron oxide) is presented. Oil shale ash (OSA) is a class-C fly ash, a by-product in the energy production process. OSA can be used as a partial replacement to cement in concretes, thanks to its cement-like qualities and low carbon content, which contributes to a reduction in the overall CO2 footprint of concrete. In our investigated concrete mixes 5 to 35% of cement was replaced by OSA (Electrostatic Precipitator Ash) coming from Auvere (Estonia) thermal power plant. Using the Monte Carlo method, the Serpent code was used to simulate the passage of neutron radiation through a composite material to assess its biological shielding properties. It is shown that the addition of basalt-boron fibre to concrete improves the protective properties of biological shielding against neutron radiation.
Derivation of mathematical model of mechanism for drive of transport means additional device
Authors: Dizo Jan , Lovska Alyona , Blatnicky Miroslav , Ishchuk Vadym , Molnar Denis
Published: July 2024

Simulations and computation are widely used in analysing and investigation of operational properties of mechanisms. Such mechanisms can be placed on transport means and they usually serve to drive additional devices. Additional devices are inseparable part of lorries, buses as well as railway vehicles, such as locomotives with independent traction. These additional devices serve for drive of compressors or other similar devices. The article is aimed at derivation of a mathematical model of a drive mechanism for a drive of an additional device of a vehicle. It is a drive mechanism, which includes several wheels and a belt. There are derived equations of motions of a drive mechanism with a rigid belt and with a flexible belt. The presented mathematical models are derived by means of the Lagrange’s equations of the second kind method. After finding the required energies, the method of the reduction of mass and force quantities to the chosen part is applied. In this case, it is reduced to the drive shaft of the considered drive mechanism. The presented mechanism with the rigid belt is described by means of one equation of motion and with the flexible belt with two equations of motion. These equations of motion are solved by means of the Matlab software. The last part of the article includes illustrations of the results in a form of graphical outputs. The presented research and the solved mechanism are a basis of creation of a multibody model. It was proven that the flexibility of the belt leads to relative deflections of the drive and driven part of the mechanism.
Production of biogas from grass at various pre-treatment and anaerobic fermentation temperatures under influence of magnetic field
Authors: Plume Imants , Azits Eduards , Dubrovskis Vilis , Plume Lauris
Published: July 2024

Biogas production from agricultural biomass is declining in Latvia, as stricter regulations propose restriction of using energy crops, e.g. maize silage, by 2030. An alternative to energy crops can be grass overgrowth biomass from abandoned areas, municipal or domestic green areas and protected areas such as roadsides, areas under power lines and others. The biomass of grass contains lot of lignocellulose, which slowly decomposes during the anaerobic fermentation (AF) process. The aim of the study was to investigate the influence of pretreatment of grass by freeze-thawing cycle at a low temperature -15 °C or -23 °C on methane yield. Also, influence of various mesophilic temperatures 25; 33 and 38 °C on production of biomethane was investigated during the AF process. Some bioreactors (volume 0.75 L) with grass biomass were added magnetic powder (MP) and/or fitted with a pair of magnets for providing of weak magnetic field (WMF). Results of the experimental setup 1 shows the increase in specific methane 68 or 75% if the grass biomass is pretreated at -15 °C and -23 °C in double freeze-thawing cycle. The highest specific methane yield 0.313 L·gVS-1 was observed from grass biomass pretreated at -23 °C, that was 100% higher compared to control. Results of setup 2 show high specific methane 0.202 L·gVS-1 from the group of bioreactors with added MP 1.0 g, moderate methane yield 0.188 L·gVS-1 under influence of WMF 3.6 µF and the highest methane yield 0.234 L·gVS-1 from combined application of MP 2.0 and WMF 3.6 µF which 24%, 15% and 44% respectively, compared to control (grass without MP addition and WMF application).
Comparison of nitrous oxide (N2O) and methane (CH4) fluxes in naturally wet and drained mineral forest soil
Authors: Skranda Ilona , Spalva Gints , Muiznieks Edgars , Lazdins Andis
Published: July 2024

The scope of the study is to determine the effect of drainage of mineral soil in forest on nitrous oxide (N2O) and methane (CH4) emissions from soil. We evaluated N2O and CH4 fluxes from soil in pine and birch stands with moderately fertile drained and naturally wet mineral soil. The N2O and CH4 fluxes in naturally wet and drained mineral forest soils are crucial for understanding their respective roles in climate change dynamics and informing sustainable land management practices that can mitigate greenhouse gas emissions. The study was implemented in eighteen stands. We took gas samples periodically (once per month in average) using the opaque chamber method (45 measurement points in total) during 18 months period. Samples were analysed in laboratory using the gas chromatography method. It was assumed that N2O and CH4 fluxes are constant during the whole rotation period, while the average annual fluxes were calculated as sum of average monthly fluxes. We also measured the groundwater (GW) depth, soil and air temperature during the gas sampling and periodically took water samples from perforated water wells for chemical analyses. We found that all measurement sites are net sinks of CH4 removals and sources of N2O emissions. We did not find higher CH4 emissions in wet soil; however, one of the measurement years contained also one of the driest vegetation seasons, and GW level was deeper than usually, potentially resulting in reduction of CH4 emissions. We did not find correlation between the air temperature and N2O or CH4 emissions, as well as between the groundwater level and efflux of these gases. However, higher groundwater level in wet areas is associated with periodic extremes of N2O and CH4 emissions, which cannot be expressed by regression equations. If these extremes are considered, then wet mineral soils are a significant source of N2O emissions, however, they can also be omitted as a non-anthropogenic source.
Mathematical modelling of chemical reaction with propane
Authors: Kalis Harijs , Kangro Ilmars
Published: July 2024

The main goal of the present study is to promote a more effective use of agricultural residues as an alternative renewable fuel for cleaner energy production with reduced greenhouse gas emissions. The complex experimental study and mathematical modelling of the processes developing during the co-firing of biomass pellets with gaseous fuel were carried out. The experimental study of the effect of co-firing on the main gasification and combustion characteristics was carried out by varying the propane supply and additional heat input into the pilot device with an estimation of the effect of co-firing on the thermal decomposition of pallets. The mathematical model is developed using the environment of MATLAB (2-D modelling) and MATLAB package “pdepe” (1-D modelling) with account variations of supplying the heat energy and combustible volatiles into the bottom of the combustor. The dominant exothermal chemical reactions were used to evaluate the effect of co-firing on the main combustion characteristics and composition of products CO2 and H2O. The results prove that the additional heat from the propane flame allows control of the thermal decomposition, the formation of volatiles, and the development of combustion dynamics, thus completing the combustion of biomass and leading to cleaner heat energy production.
Methane (CH4) and nitrous oxide (N2O) emissions from surface of deciduous tree stems and soil in forests with drained and naturally wet organic soils
Authors: Skranda Ilona , Purvina Dana , Bardule Arta , Petaja Guna
Published: July 2024

In general, the groundwater level (GWL) in forests with organic soils plays a crucial role in greenhouse gas (GHG) emissions from both the soil and the surface of tree stems. High GWL typically leads to anaerobic conditions in the soil, reducing the emission of GHG like nitrous oxide (N2O) and increasing methane (CH4) emissions. Understanding and managing GWL in such ecosystems is therefore essential for mitigating GHG emissions. The scope of the study was to evaluate magnitude of fluxes of GHG (specifically CH4 and N2O) from the surface of deciduous tree stems and soil, as well as to find interrelationships with environmental factors like GWL and the soil temperature. CH4 and N2O fluxes from tree (black alder, silver birch and aspen) stems and soil were monitored in 10 study sites in forest stands with drained and naturally wet organic soils in Latvia in 2022 and 2023. We found that the surface of tree stems was a net source of CH4 and N2O emissions in forests with both drained and naturally wet organic soil. MeaN·magnitude of CH4 fluxes from tree stems were 0.017 ± 0.003 mg CH4-C·m-2·h-1 in forest stands with drained organic soil and 0.032 ± 0.010 mg CH4-C·m-2·h-1 in forest stands with naturally wet organic soil, while meaN·magnitude of N2O emissions were 0.002 ± 0.001 and 0.007 ± 0.002 mg N2O-N·m-2·h-1, respectively. Thus, emissions from the surface of tree stems under naturally wet soil conditions were higher than under drained conditions; a statistically significant difference was found only for N2O. Drained organic soils in the study sites were a net sink of CH4 (small removals were observed), while naturally wet soils created emissions (mean 1.15 ± 0.89 mg CH4-C·m-2·h-1). The magnitude of N2O emissions from soil was similar for naturally wet and drained conditions (0.034 ± 0.017 and 0.028 ± 0.014 mg N2O-N·m-2·h-1, respectively). In general, the study showed that drainage of organic soils in forest lands can reduce CH4 and N2O emissions; however, due to high variation in studied GHG fluxes, the number of measurement points should be increased to prove the significance of the difference.
Research on influence of geometric parameters of engine body parts during repair process
Authors: Novytskyi Andriy , Melnyk Valentyna , Banniy Oleksandr , Bystryі Valeryi , Stetsiuk Serhii
Published: July 2024

Exterior parts of complex constructions are widely used in internal combustion engines for various purposes, such as pumps, compressors, etc. Solving the problem of high-quality repair of parts of complex configuration, effective control of their technical condition during their reuse requires solving a number of engineering, technological and metrological tasks. The durability of modern cylinder blocks is ensured by the use of high-quality materials, improved element construction, equal strength of parts with optimal manufacturability, maintainability, quality of assembly and service. To conduct the research, technological schemes for monitoring and measuring deviations in the location of the main geometric parameters of the cylinder block were developed. Engineering documentation and technological support for the manufacture of a control and measuring device for controlling the alignment of the holes of the main bearings were developed. Processing of the measurement results by indicator devices in the workshop conditions shows that the deviation from the alignment or displacement of the middle root supports relative to the extreme ones can reach a value of -0.08 to +0.09 mm, which is significantly beyond the diameter limit. The values of the results show that the maximum deviations occur in the horizontal plane (1800 - 3600) with a transition to the lower part of the vertical plane. This direction of displacement can be explained by the zone of maximum values of the forces acting during the engine operation. It should be assumed that the values of actual deviations in the range of -0.04 to +0.04 can be accepted for the use of cylinder blocks. The construction of the device with indicator counting devices was developed to ensure control and measurement of the alignment of the holes of the main bearings. Laboratory tests of the device and metrological evaluation of the permissible measurement error were carried out. The results obtained made it possible to increase the productivity of defect detection work and develop recommendations for improving the aftermarket reliability of engines.
Application of topological modelling methods for determining human fatigue
Authors: Erins Matiss , Markovics Zigurds
Published: July 2024

Fatigue is a complex concept that is simultaneously a physiological, psychological, and social phenomenon which pathophysiology is still not fully understood. Solutions offered by modern technologies are also still unable to prevent economic losses, but even more importantly not to lose human resources in high-risk sectors such as transport and operations. If the fatigue topological model (TM) is created in the form of a directed graph, the analysis provided by such a model in the main problem solution on the level of expression of human fatigue remains to be performed. First, the model makes it clear that in practice the often-combined terms fatigue (F) and drowsiness (D) are neither the same nor the opposite in nature. The graph configuration will clearly indicate the routes belonging solely to F and belonging solely to D, as well as the routes common to F and D. Secondly, based on the graph theory, a formal algorithm enables a selection task to be performed to select the most efficient set of parameters to measure fatigue. The method of selection is derived from the so-called table overlay method. In practice, this method is justified because there are no parameters that can be measured only under laboratory conditions, or the sensor is inconvenient to perform the work. The resulting parameters selected from TM can be obtained with one touch sensor placed on the head. The rest of the information comes from a remote camera, test results and self-survey data.
Influence of industry on air pollution in Jelgava city
Authors: Grinfelde Inga , Siltumens Kristaps , Grybauskiene Vilda , Bertins Maris , Pilecka-Ulcugaceva Jovita
Published: July 2024

Air pollution is one of the most important environmental issues in the urban environment and causes health risks for citizens. The small particles PM 2.5 and PM10 consist of different trace elements. Industrial activities such as smelting, refining, and combustion processes are releasing significant amounts of metals into the air, leading to extensive air pollution. The aim of this study is to identify in which parts of Jelgava city the risks of air pollution caused by industry are the greatest. The snow samples were collected from 59 monitoring points in Jelgava and one in a rural area as reference. The snow samples were analysed using ICP MS for Al, Si, Cr, Mn, Fe, Ni, Cu, Zn, As, Mo, Cd, Ba, W, and Pb concentration analysis. The hierarchical cluster analysis of normalized chemical element concentrations was used to divide monitoring points into four groups with high, medium-high, medium, and low risks of industrial air pollution. The industrial air pollution risks are unevenly distributed in Jelgava. High and Medium high risks are indicated in residential areas. The trace element concentration distribution shows significant differences between industrial air pollution risk groups. Kruskal-Wallis test shows statistically significant differences between the clusters for all trace elements (p-value < 0.0001; alpha 0.05). The results show strong evidence of industrial air pollution in Jelgava city. Mostly in Jelgava city dominates low and medium risk of industrial air pollution, however, there are three points with high industrial air pollution risks.
Bifurcation analysis of dynamical system with nonlinear dashpot and impacts
Authors: Sokolova Svetlana , Viba Janis , Jevstignejevs Vladislavs
Published: July 2024

A nonlinear viscous damper is a type of damping device used in engineering to dissipate energy and reduce vibrations in structures. Damping is essential in many engineering applications to control the response of structures subjected to dynamic loads, such as earthquakes, wind, or machinery-induced vibrations. In a nonlinear viscous damper, the damping force is not directly proportional to the velocity of the structure, which distinguishes it from linear viscous dampers. The nonlinearity in the damping force-velocity relationship can be designed to provide specific performance characteristics. The main reasons for employing nonlinear viscous dampers include increased energy dissipation – nonlinear viscous dampers can provide higher energy dissipation compared to linear dampers, making them effective in controlling larger vibrations. This work deals with numerical analysis of a single degree of freedom dynamical system representing plate-flow interaction with quadratic drag force subjected to harmonic excitation with and without additional impacts during oscillations. Numerical analysis is based on the bifurcation theory. The theory focuses on understanding the qualitative changes in the behaviour of a system as a parameter is varied. Without additional stoppers the system behaves as a linear system. With “soft” stoppers the system gets limited displacements with the same velocities, multiplicity and more uniform distribution of amplitudes of oscillations. Understanding bifurcations is crucial in predicting and controlling the behaviour of dynamic systems, especially when dealing with nonlinear phenomena.
Biosynthesis and use of laccases produced by basidiomycetes for treatment of agri-food waste: review
Authors: Ferdes Mariana , Dinca Mirela-Nicoleta , Ionescu Mariana , Stefan Elena-Madalina
Published: July 2024

Recently, due to global concerns regarding the growing accumulation of waste, increased attention is directed towards new ways of using lignolytic enzymes, as a means of reducing environmental pollution coupled with obtaining new useful products. Valorization of lignocellulosic food waste and its components into different value-added products requires disruption of the recalcitrant structure of the lignocellulosic component. In this paper lignolytic enzymes produced by phyllum Basidiomycota, as well as other enzymes that participate in the degradation of agri-food waste are summarized. The aim of this review is to give an overview on the biosynthesis and use of laccases for enzymatic treatment applied to agri-food waste. The methodology consisted in the research of the most representative sources from the literature of recent years and the synthesis of the respective studies, for an overall study. There are presented different types of agri-food waste generated by the fruit and vegetable, grain, wine, and beer processing industries. The main species of basidiomycetes that produce lignocellulosic enzymes are mentioned, as well as the conditions for their cultivation. The methods of selecting the producing fungal strains by screening on chromogenic media, the analysis of the enzyme activity, the stages of the biosynthesis process, the factors that influence the accumulation of the enzyme are described. The article includes information related to the structure and treatment of lignocellulosic materials from vegetable food waste, the mechanism of action of laccase, as well as the current state of research in the direction of using these enzymes for the treatment of food waste.
Impact of soil organic pollutants on different types of crops - review
Authors: Stefan Elena-Madalina , Istrate Irina-Aura , Constantin Gabriel-Alexandru , Voicu Gheorghe , Ferdes Mariana , Munteanu Mariana Gabriela
Published: July 2024

The organic pollutants of soil like associated petroleum hydrocarbons are a major source of concern for food safety, especially in underdeveloped and developing countries of the world. The increasing concentrations of toxic compounds in agricultural soils contaminated with organic pollutants affect physiology, biochemistry and development and growth of crops, and overall productivity. Organic pollutants can degrade soil structure, disrupt microbial communities, and reduce soil fertility. Due to the difference in the composition and concentration of the different organic pollutants, they have impact on soil, on plant growth and development in different ways and at different rates. The current review aims to give an overview of the response of plants to organic pollution according to factors such as the type, composition, concentration, persistence of organic pollutants, type and characteristics of soil, plant species and climate. Petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) are part of the most significant classes of organic pollutants, due to their long-term environmental persistence, long-term toxicity, bioaccumulation, and biomagnification properties of living tissues. Up to 90% of all petroleum hydrocarbons are deposited in the soil due to their high hydrophobicity, which improves the rapid interaction with soil particles and their permeability in the lower layers. Thus, this review summarizes the current state of research on the effects of organic pollutants, hydrocarbons especially, on physiology, biochemistry, development and growth of crops.
Displacement of high-parafin oil from formations by injected cold water
Authors: Bayamirova Ryskol , Togasheva Aliya , Zholbasarova Akshyryn , Sarbopeyeva Manshuk
Published: July 2024

When cold water is injected into reservoirs, the reservoir temperature near the injector wells decreases and becomes lower than the wax saturation temperature of the oil. As a result, wax is precipitated from the oil in the porous medium of productive horizons, negatively impacting the development of oil reservoirs. The need to take into account the characteristics of oils and reservoir systems when designing the development of oil fields applies both to deposits of high-viscosity oils, in which, with increasing the reservoir temperature, viscosity decreases and oil mobility increases, intra-reservoir hydrodynamic resistances decrease, which improves the flow of fluids to producing wells, and to deposits of low-viscosity oils saturated with paraffin. The article addresses the question of the effectiveness of hot water injection. Hot water injection is only meaningful when the oil (or gas equivalent to oil) consumption for heating the water is less than the potential oil losses during cold water injection. The problem of research on cold water injection is relevant and necessary to optimize oil production processes. Changes in the reservoir pressure and temperature are important in assessing the effectiveness of the flooding method to increase oil recovery at the Uzen field of the Republic of Kazakhstan. The paper presents theoretical models based on real data that were used for calculations. The criteria for the effectiveness of hot water injection include such indicators as an increase in oil production, increase in the reservoir pressure efficiency, decrease in oil viscosity to improve its flowability, as well as a reduction in production costs.
Dynamics of deep loosener loading during agrotechnical tillage operations
Authors: Artiomov Nikolay , Anikeev Aleksandr , Kaluzhnij Aleksandr , Tsiganenko Mikhail , Pushkarenko Oleg
Published: July 2024

Modern agriculture requires introduction of rational, energy-saving and environmentally friendly agro-technologies. In recent years, special attention has been paid to the issues of preserving the fertility of agricultural land. One of the problems faced by farmers and agricultural enterprises is excessive soil compaction. This problem has arisen due to the steady tendency of increasing the weight of agricultural machinery, in connection with this negative impact of heavy machinery the subsoil layer is also compacted in addition to the arable layer. The depth of soil compaction depends on the tractor weight, frequency of passes, moisture, type and the condition of soil. Besides repeated passes of machines, soil compaction is also promoted by repeated plowing of soil to the same depth, which causes formation of so-called plow sole with hardness more than 3.5 MPa. Excessive soil compaction blocks the rise of soil moisture through capillaries from the depth of water-bearing layers. Soil compaction is felt by almost all agricultural crops through limitation of water supply to the root system of plants. One way to combat soil over-compaction is deep loosening or chiseling, sometimes referred to as vertical tillage. Also, soil loosening provides improved water and air regime. Under certain conditions, deep loosening can replace plowing. The paper studies the loading dynamics of deep loosening machines, which have been used for soil decompaction in tillage systems, which is of scientific and practical interest. To study the dynamics of deep loosener loading, a measuring and registration complex developed at the university was used. This complex allows to control in real time the load parameters of an agricultural machine without interfering with its design.
Battery thermal management system for greater lifetime and safety: mini-review
Authors: Madani SeyedSaeed , Hajihosseini Mojtaba , Ziebert Carlos , Nandhakumar Iris
Published: July 2024

In this review paper, we make a collective effort to enhance our comprehension of thermal control systems for lithium-ion batteries, focusing on various aspects including cooling techniques, design adjustments, temperature distribution, and energy efficiency. This compilation of research studies delves into the crucial field of thermal management systems for lithium-ion batteries, addressing a range of factors to boost their performance and safety. The updated analysis aims to critically evaluate these systems with a focused objective on assessing their reliability under various operational conditions. By examining different cooling methods and design modifications, we highlight their implications for enhancing battery safety and operational stability, providing insights into how these systems can be optimized to improve performance and reliability. This review underscores innovative approaches and critical findings that contribute to the reliability and efficiency of these systems, offering a foundation for future advancements in battery technology. Key findings suggest that advanced cooling configurations and design adjustments significantly contribute to battery stability, indicating directions for future research to optimize these systems further.
Agrobiomass of Ukraine – Energy Potential of Central and Eastern Europe (Engineering, Technology, Innovation, Economics)
Authors: Glowacki Szymon , Hutsol Taras , Mudryk Krzysztof , Yermakov Serhii , Kucher Oleg , Knapczyk Adrian , Muliarchuk Oksana , Koberniuk Olena , Kovalenko Nataliia , Kovalenko Vitalii , Ovcharuk Oleh , Prokopchuk Liliia
Published: July 2024

The monograph covers current research in the field of energy potential of biomass. The issues of world scientific and research trends in the field of biomass energy and the current state of bioenergy in the EU and Ukraine in the context of opportunities to increase the volume and improve the properties of raw materials for renewable energy based on biomass. The presented materials are intended for masters, graduate students, engineers and scientists involved in the design, testing and operation of agricultural machinery.
Oczekiwania konsumentów pokolenia Z dotyczące zakupówproduktów spożywczych prosto od rolnika
Authors: Krzyżanowska Krystyna , Parzonko Anna , Sieczko Anna
Published: July 2024

W artykule zaprezentowano wyniki badań empirycznych1 dotyczących oczekiwańkonsumentów pokolenia Z związanych z zakupem produktów spożywczych prosto od rolnika.W badaniach wykorzystano metodę sondażu diagnostycznego z zastosowaniem technikiankiety. Przeprowadzono je z wykorzystaniem autorskiego kwestionariusza ankiety, sporządzonegona platformie Webankieta w marcu 2024 r. na grupie 246 respondentów. Z badańwynika, że pokolenie Z w znaczącym stopniu wykazuje zainteresowanie zakupami produktówspożywczych prosto z gospodarstwa. W przypadku takich zakupów dla respondentów ważnebyły skład produktu i prawidłowe warunki utrzymania zwierząt. Badani preferowali bezgotówkoweformy płatności za pomocą karty płatniczej lub płatności mobilnej (BLIK).
Evaluation of Fomitopsis betulina strains for growth on different media and exopolysaccharide production
Authors: Kizitska Tetiana , Barshteyn Viсtor , Sevindik Mustafa , Krupodorova Tetiana
Published: July 2024

Fomitopsis betulina is a widespread macromycete with valuable medicinal potential. This study screened 22 different F. betulina strains for mycelial growth on various media and exopolysaccharide production. Strain-specific features of F. betulina growth and exopolysaccharide production on different media were observed. Variations in the growth rate of the studied strains ranged from 3.50?0.33 to 8.75?0.50 mm/day, biomass synthesis from 2.28?0.26 to 13.72?0.05 g/L, and exopolysaccharide production from 0.02?0.00 to 2.20?0.31 g/L. Maltose as a carbon source in malt extract agar (MEA) and malt extract broth (MEB) was the most suitable for the growth, while dextrose and starch as carbon sources in potato dextrose broth (PDB) were more suitable for exopolysaccharide production. The F. betulina 311 strain has significant biotechnological potential, demonstrated by its robust growth on different agar media, efficient biomass synthesis, and high production of extracellular biopolymers. Our results highlight the significance of different growth media and fungal strains in optimizing biomass and exopolysaccharide production.
Intolerance of gluten-containing cereals
Authors: Lekovic Zoran , Radlovic Vladimir , Mladenovic Marija , Ducic Sinisa , Rosic Petar , Djuricic Goran , Predojevic-Samardzic Jelica , Radlovic Nedeljko
Published: July 2024

Intolerance of gluten containing cereals (wheat, rye, and barley) is an etiopathogenetically heterogeneous and relatively common problem of modern man. It occurs as an adverse immune-mediated condition in genetically predisposed individuals. According to the pathogenetic mechanism of intolerance to the components of these cereals, it is classified into celiac disease as an autoimmune disease, wheat allergy as an allergic disease, and non-celiac gluten sensitivity as a non-autoimmune and non-allergic disease. Each of these disorders is characterized by specific intestinal and/or extraintestinal manifestations, which resolve on a gluten-free diet. This review article presents the basic characteristics of these disorders in accordance with modern knowledge.
Capacitance breakthroughs in free-standing electrodes through MXene functionalization
Authors: Pesic Ivan , Pergal Marija , Vasiljevic-Radovic Dana , Popovic Maja , Uskokovic Petar , Petrovic Milos , Radojevic Vesna
Published: July 2024

The discovery of the large group of 2D materials called MXenes has gathered
much attention due to their potential applications in various fields as well
as the evergrowing discoveries about their nature. One of the most
interesting applications is energy storage devices. Herein, we demonstrated
the impact of the functionalization with two different silanes on the
electrochemical and structural properties of Ti3C2Tx MXene. Materials are
prepared and characterized as free-standing films obtained by a simple
vacuum filtration method. The structure of the modified MXene electrodes was
confirmed via SEM, FTIR, and XPS analysis. At the same time, the
electrochemical properties were determined by cyclic voltammetry and
galvanostatic charge-discharge in a two-electrode setup in aqueous
electrolyte. Capacitance values at lower scanning speeds revealed the
benefits of PEG silane functionalization (25.38 F/g), showing higher values
compared to pure MXene (23.95 F/g) and MEMO silane (23.37 F/g). Capacitance
retention decreased with the addition of silanes, but there was a
significant increase in capacitance in the first 100 cycles. This study
clarifies the benefits of adding different silanes to the structural and
electrochemical properties of MXene for energy storage applications.
Investigation of the mechanical properties of concrete incorporating recycled rubber particles
Authors: Stojanovic Marko , Supic Slobodan , Jankovic Ksenija , Bojovic Dragan , Terzic Anja , Malesev Mirjana
Published: July 2024

Quantity of waste rubber generated by automobile tires is growing, posing an
environmental threat. Rubber tire recycling was studied for usage in asphalt
and waterproofing systems during past few decades. Globally, concrete is the
most widely used building material. About 7% of CO2 emissions come from the
cement production. The purpose of this research is to assess if using waste
rubber and Portland cement together in composite material for structural
applications is feasible. Waste tires (shredded to 0/1 mm) were used as fine
aggregate replacement (in 2.5 and 7.5 %), together with PC and natural
stone. An investigation of properties in fresh (slump test, bulk density,
air content) and hardened state (bulk density, compressive strength) was
performed on the rubberized concrete. The compressive strength decreased by
increasing the rubber content for all w/c ratios (0.55-0.4). The addition of
fine-sized rubber did not cause a retardation in cement hydration mechanism.
According to the obtained compressive strengths, all designed rubberized
concretes belong to a group of structural concretes.
Writing Introductions: A Framework and Commentary
Authors: Hogan Chris E. , Myers Linda A. , Wilkins Michael S.
Published: July 2024

The introduction is the most important part of an academic paper. Beyond summarizing a paper’s findings, it is also the author’s first and best opportunity to “sell” the paper to readers with varying levels of interest. Our purpose in this commentary is to provide a framework for writing high-quality introductions. We present a specific structure and also provide guidance regarding content—both what to include and what not to include. Finally, we offer recommendations for revising the introduction as a paper evolves and present additional suggestions for writing in general. Although our primary intended audience is Ph.D. students and early assistant professors, experienced faculty members may benefit as well.
Hubungan Posisi dan Lama Duduk dengan Nyeri Punggung Bawah pada Mahasiswa Pendidikan Dokter Universitas Andalas
Authors: Nur'aisyah Shafira , Sahputra Roni Eka , Ali Hirowati , Noverial Noverial , Revilla Gusti , Fadila Zurayya
Published: July 2024

Nyeri punggung bawah adalah rasa nyeri yang dirasakan di daerah lumbal atau lumbosakral dan merupakan keluhan muskuloskletal tersering. Penelitian ini bertujuan untuk mengetahui hubungan antara posisi dan lama duduk dengan kejadian nyeri punggung bawah pada mahasiswa Pendidikan Dokter Fakultas Kedokteran Universitas Andalas. Penelitian ini menggunakan Roland-Morris Disability Quesionarre untuk menentukan nyeri punggung bawah secara objektif dan numeric pain rating scale  untuk menentukan nyeri punggung bawah secara subjektif. Penelitian ini membandingkan kejadian saat pembelajaran daring (Maret 2020—September 2021) dan luring (Oktober 2021—November 2022).Data diambil pada Desember 2022. Data dianalisis dengan uji chi-square. Tidak terdapat perbedaan bermakna  antara posisi duduk dengan kejadian nyeri punggung bawah secara objektif saat daring dan luring (p>0,05), namun terdapat perbedaan bermakna antara posisi duduk dengan kejadian nyeri punggung bawah secara subjektif saat daring dan luring adalah (p<0,05). Lama duduk tidak berbeda bermakna dengan kejadian nyeri punggung bawah secara objektif dan subjektif saat daring dan luring (p >0,05). Disimpulkan bahwa terdapat hubungan antara posisi duduk dengan kejadian nyeri punggung bawah secara subjektif saat daring dan luring namun tidak terdapat hubungan secara objektif. Tidak terdapat hubungan antara lama duduk dengan kejadian nyeri punggung bawah secara objektif dan subjektif saat daring dan luring.