Exchange Energy Research Articles

Electrically controllable spin polarization in collinear antiferromagnetic junctions

Antiferromagnetic spintronics is a rapidly growing subfield of spintronics in condensed-matter physics and information technology. Electrical current in collinear antiferromagnetic materials is typically spin unpolarized, limiting the realization of antiferromagnetic spintronics effects. Here we study the transport in the collinear antiferromagnetic junctions by applying a transverse electric field E y to the antiferromagnets (AFs). The band structures of the collinear AFs may become spin-polarized when the combined time reversal and lattice translation symmetry is broken by E y . The separation between spin-up and spin-down bands is controlled by E y . Full spin polarization originating from spin-polarized states near the band gap’s edges is observed at high exchange energy. In particular, as E y increases, the region capable of generating high spin polarization broadens due to the increased separation between spin-up and spin-down bands. The amplitude and sign of spin polarization can be controlled by E y . These characteristics indicate that collinear AF materials are ideal for future spintronics applications.

Active balancing control for distributed battery systems based on cooperative game theory

For the smooth integration of renewable and volatile energy sources in the electricity grid, there is a need for scalable and efficient storage systems. Stationary battery systems provide the required efficiency but lack the scalability to meet varying requirements. In this article, we present a novel distributed control approach for active balancing of battery cells facilitating a scalable and flexible battery system design. For the proposed algorithm, the topology of the underlying battery system is assumed to be not predefined and can change at runtime. In such a system, each battery cell may has its own power electronics and processing unit which are used to manage the control actions for active balancing on cell level. Thus, the battery system is objected as a multi agent system (MAS) with battery cells as agents. Each agent locally computes and optimises its own control actions in a leaderless MAS setup based on cooperative bargaining games and the Nash solution. Each cell is required to find a single partner or multiple partners to form coalitions and exchange energy for active balancing. The working principle and capability of the distributed control algorithm is evaluated by simulations and compared to a passive balancing approach and a central optimal control algorithm.

Вплив генетично модифікованої сої на продуктивність і якість м’язової тканини свиней

Goal. To study the productive and slaughter qualities of young pigs and the chemical composition of muscle tissue and liver for the use of high-protein fodder — narrow-leaf lupine and genetically modified (GM) soybeans as a part of fodder grain mixes. Methods. In the experiment, two groups of experimental animals were formed: the first group (control) was fed with grain mixture № 1 with narrow-leaved lupine (alkaloid-free) and sunflower cake; the second group (experimental) received grain mixture № 2 with GM soy. The live weight of young pigs was determined by individual weighing before morning feeding, feed payment by live weight gain — by calculation method, slaughter quality — by the technology used at meat processing enterprises, and chemical composition — by generally accepted methods. Laboratory studies of soy, muscle tissue, and liver for the content of genetically modified organisms were carried out at the Ukrainian Laboratory of Quality and Safety of Agricultural Products. Results. Soybeans contained genetically modified desoxyribonucleic acid (DNA), had a target promoter sequence 35S + FMV of Cauliflower mosaic virus, and the NOS-terminator (nopaline synthase) of Agrobacterium tumefaciens. According to the results of qualitative analysis of the longest back muscle and liver of young pigs, no genetically modified organisms and products containing them were found. Conclusions. Optimizing the protein nutrition of young pigs due to genetically modified soybeans compared to the use of lupine and sunflower cake harmed live weight and average daily gains of animals (–11.6%) with the higher expenditure of exchangeable energy (+20.5%) per unit of gain. A comparative analysis of the chemical composition of the longest back muscle of gilts showed that in the muscle tissue of animals of the II (experimental) group, the concentration of dry matter, protein, and ash was lower by 0.60%, 1.10 and 0.08% abs., respectively, and fat — by 0.58% abs. greater than in animals of the I (control) group.

Towards a universal exchange enhancement factor in density functional theory

A broadly used strategy to go beyond the well-known local-density approximation of density functional theory relies on the choice of a so-called exchange-correlation (xc) enhancement factor ${F}_{\mathrm{xc}}$, defined as the enhancement of a realistic xc energy density over its local exchange-only counterpart. To date, this density functional, ${F}_{\mathrm{xc}}$, has been constructed by following either semiempirical strategies or nonempirical schemes that impose the fulfillment of exact constraints. Here, we follow a totally different route, which is based on an attempt to construct a universal exchange enhancement factor ${F}_{x}$ from the exact exchange energy density of a given family of electron density profiles and which we implement on the basis of jellium-slab exact-exchange self-consistent calculations. We find that such an enhancement factor can, indeed, be built which obeys, within our sample of electron-density profiles, most exact constraints and thus represents a benchmark towards the construction of a universal exchange enhancement factor suitable for all electron densities. We provide, in particular, an analytical parametrization of our ab initio calculations at the level of the generalized gradient approximation.

Energies of the ground and excited states of confined two-electron atom in finite potential well

For the ground and excited configurations, we have carried out the energy eigenvalues and corresponding wavefunctions of two-electron atom enclosed by finite confining potential by using Quantum Genetic Algorithm (QGA) procedure and Hartree-Fock Roothaan (HFR) method. Besides, we have analysed in detail orbital energies and probabilities of finding electron for the configurations 1S (1s2), 3S (1s2s), 3P (1s2p), 3D (1s3d) and 3F (1s4f). The results reveal that the potential barrier height plays a significant role on average energies, state energies, orbital energies and probabilities of finding electrons in orbitals. As dot size is extremely small and extremely large, the energies for 1snl configurations are getting close to each other, but between these two extreme situations they are separating from each other. While going to higher excited states, singlet and triplet states are almost the same due to the weakening of the exchange energy.

First-principles calculations to investigate role of 4d electrons spin (Mo/Tc) in half metallic ferromagnetism, and thermoelectric characteristics of Rb2(Tc, Mo)X6 (X =Cl, Br)

The absolute spin polarization, stable structures, and non-toxic nature of vacancy-ordered double perovskites (DPs) make them merging materials for spintronic. Therefore, in the present study, the role of 4 d electrons of Mo/Tc has been focused comprehensively to monitor the ferromagnetism in Rb2(Tc, Mo)X6 (X = Cl, Br). The electronic and magnetic behaviors have been analyzed by modified Back and Johnson potential and thermoelectric effect by BoltzTrap code. The tolerance and octahedral factor show the existence of structures, while formation energy calculations ensure thermodynamic stability. The density of electron states at the Fermi level and the Heisenberg model report the spin polarization and Curie temperature. The density of states exposed half-metallic ferromagnetism and the transition of electrons spin to endorse the exchange mechanism. The control of ferromagnetism by electron functionality has been analyzed regarding exchange energies, crystal field energies, double exchange model, exchange constants, and hybridization process. Furthermore, shifting a magnetic moment from Mo/Tc to Rb and Cl/Br sites dominates the ferromagnetism due to the exchange of electrons spin instead of magnetic clusters. Finally, the Seebeck coefficient, conductivity of electrons, and power factor have discussed the thermoelectric effect on spin functionality and thermoelectric performance.

Impact of electrons spin on ferromagnetism and thermoelectric properties of BaFe2(S/Se/Te)4 for spintronic and green energy applications

Spintronic is an emerging field of advanced technology that controls the spin of electrons to transfer, handle, and store data simultaneously at a very fast rate. To improve it further, we have systematically studied the electronic behavior, ferromagnetism, and thermoelectric characteristics of BaFe2(S/Se/Te)4 spinel's. The optimization analysis shows the ferromagnetic states release more energy as compared to the antiferromagnetic states. Therefore, the studied compounds are existing in ferromagnetic states. The Heisenberg model is employed to calculate the spin polarization and Curie temperature to confirm above room temperature ferromagnetism. Furthermore, the nature of ferromagnetism, density of states, band structures, exchange constants and exchange energies, hybridization, crystal field energy, and double exchange model are addressed briefly. Shifting of the magnetic moment from Fe to Ba and S/Se/Te sites reveals that ferromagnetism is credited to the spin of electrons rather than the clustering of magnetic ions (Fe). Moreover, the thermoelectric parameters like Seebeck coefficient, conductivities, and power factor for spin-up (↑) and spin-down (↓) are explored to reveal how electron spin is affected by thermal parameters and for energy harvesting.

Effects of physical exercise on glycemic metabolism, aerobic capacity and structure of brown adipose tissue in diabetic animals

The ability of brown adipose tissue (BAT) and aerobic physical exercise (AET) to improve energy metabolism is widely known. Since AET has been used as an insulin- sensitizing therapy for diabetes, here we tested whether the effects of AET on the glycemic metabolism and aerobic capacity of diabetic animals are accompanied by structural changes in BAT. Adult male C57BL6/J mice were assigned into groups: non-diabetic sedentary (NDS, n=6), non-diabetic trained (NDT, n=6), diabetic sedentary (DS, n=4) and diabetic trained (DT, n=7). Diabetes was induced by high-fat and -fructose diet and intraperitoneal injection of streptozotocin (120 mg/g). AET consisted of 8-wk running session of 60 min at 60% of maximal speed, 5 days/wk. Experimental procedures were approved by Ethics Committees from Faculty of Medicine and from School of Arts, Science and Humanities of University of São Paulo (#1473/2020 and #001/2020, respectively). Initial body weight (BW) did not differ among groups, however the DS and DT groups had lower final BW compared with NDS. The BW gain of DS group was lower compared with NDS group. Food consumption (Kcal/animal/day) was higher in DT group compared with NDS and NDT. The DS and DT groups had higher fasting blood glucose, and DS group had greater area under the curve on the glucose tolerance test than the NDS and NDT groups. Indirect calorimetry measurement at rest revealed no difference in the variables oxygen uptake (VO2), carbon dioxide expiration (VCO2), respiratory exchange ratio (RER), energy expenditure (EE), carbohydrate and fat oxidation among groups. During maximal exercise test, NDT and DT increased the time to exhaustion, maximal speed, intensity corresponding to the VO2máx (iVO2) compared with NDS and DS. An increase in VO2máx and VCO2máx was observed in NDT group compared with DS and DT group. No differences were observed in the weight of white adipose tissue depots (retroperitoneal, periepididymal and subcutaneous), interscapular brown adipose tissue (iBAT), skeletal muscle (gastrocnemius and soleus), and other organs (heart, lung, and kidney). Morphometric analysis of the iBAT revealed that the area, diameter, volume, mass, frequency of lipid droplet distribution by size (small, medium, large, and very large) and amount of lipid droplets did not differ among groups, however, collagen deposition in the iBAT increased in the DS and DT groups compared with NDS group. In conclusion, the AET-induced improvement in glucose tolerance and aerobic capacity in diabetic animals is not accompanied by changes in morphometry and collagen deposition in the iBAT. This study was supported by grants from the São Paulo Research Foundation (FAPESP) #2020/15748-4 and #2020/12005-0. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

New testing method for the evaluation of topographical gradients of varying strength

Passive gradient motion found in nature is becoming a point of interest for heat exchange and green energy technologies. Surfaces with a topographical gradient could potentially enhance heat exchanger performance, promote dropwise vs filmwise condensation, or delay icing on wind turbines by assisting in the removal of condensed or impacted droplets. Coating-free topographical surface tension gradients can be fabricated via various methods and need to be examined in terms of their capability for spontaneous droplet motion. In this work, a simple experimental method, coupled with numerical modeling and force analysis, for examining variable-pitch micro/nanoengineered hierarchical superhydrophobic gradients is shown. The method was validated against numerical calculations, allowing the strength of the gradients to be compared. In most cases, model predictions for droplet travel distance and velocity were within 20% of the measured data. This method could also be useful for gradient design improvements in the absence of spontaneous motion on a horizontal surface.

Perfect control of spin, valley and spin-valley-coupled currents in bilayer graphene on WSe2 magnetic junction: Effect of spin-valley dependent Fermi level and energy gap

We investigate the spin-valley dependent transport properties in a gated bilayer graphene (BG) junction placed on top of WSe2. By means of layer-dependent proximity, the spin–orbit interaction (SOI) is induced in the bottom layer, while the top layer is induced into ferromagnetism by a magnetic insulator. As a result of these differing properties, the Fermi level and energy gap become spin-valley dependent, which could lead to controllable spin- and valley-dependent filtering in the BG system. Our findings predict perfect spin-valley polarization control through gate control, given specific energy and electric field conditions, as well as spin-valley-coupled and spin currents when both the electric-field-induced energy gap and the exchange energy are equal to the SOI strength. We predict that there will be very highly sensitive gate control of −100% to + 100% of spin-valley-coupled polarization for large barrier thickness. Additionally, we predict 100% valley polarization can be controlled by the gate when the exchange energy is equal to the SOI. Furthermore, we found that the performance of the junction to control the polarizations can be enhanced by increasing the thickness of the junction. This work reveals the potential of the BG/WSe2 hybrid structure for spin-valley-current-based electronics, such as spin-, valley-, and spin-valley field-effect transistors.

Sparse tensor based nuclear gradients for periodic Hartree-Fock and low-scaling correlated wave function methods in the CP2K software package: A massively parallel and GPU accelerated implementation.

The development of novel double-hybrid density functionals offers new levels of accuracy and is leading to fresh insights into the fundamental properties of matter. Hartree-Fock exact exchange and correlated wave function methods, such as second-order Møller-Plesset (MP2) and direct random phase approximation (dRPA), are usually required to build such functionals. Their high computational cost is a concern, and their application to large and periodic systems is, therefore, limited. In this work, low-scaling methods for Hartree-Fock exchange (HFX), SOS-MP2, and direct RPA energy gradients are developed and implemented in the CP2K software package. The use of the resolution-of-the-identity approximation with a short range metric and atom-centered basis functions leads to sparsity, allowing for sparse tensor contractions to take place. These operations are efficiently performed with the newly developed Distributed Block-sparse Tensors (DBT) and Distributed Block-sparse Matrices (DBM) libraries, which scale to hundreds of graphics processing unit (GPU) nodes. The resulting methods, resolution-of-the-identity (RI)-HFX, SOS-MP2, and dRPA, were benchmarked on large supercomputers. They exhibit favorable sub-cubic scaling with system size, good strong scaling performance, and GPU acceleration up to a factor of 3. These developments will allow for double-hybrid level calculations of large and periodic condensed phase systems to take place on a more regular basis.

Electronic, Structural, Optical, and Magnetic Characteristics A2MgS4 of (A=Dy, Er) Spinel Sulfides: A Density Functional Theory Study

Density functional theory (DFT) simulations are performed to explore the physical features of Dy2MgS4 and Er2MgS4. Local density approximation with Hubbard potential (LDA + U) functional is utilized to examine the magnetic and electronic features. Half metallic ferromagnetic (HMF) behavior is confirmed by the spin‐resolved density of states (DOS) and band structure (BS) plots. Spin‐resolved BS and DOS show that Dy2MgS4 and Er2MgS4 for spin‐down are metallic, whereas both compounds in spin‐up show semiconductor nature with the bandgaps of 1.731 and 3.081 eV for Dy2MgS4 and Er2MgS4, correspondingly. Both compounds also feature exchange energies and crystal field splitting, indicating the magnetic characteristics. The estimated magnetic moments of X2MgS4 (X = Dy, Er) are 20μB and 12μB, correspondingly, also revealed by spin‐polarized magnetic density. Optical properties such as refractive index n(ω), absorption coefficient α(ω), dielectric constant , reflectivity R(, extinction coefficient k(ω), and optical conductivity σ(ω) are also explored. The optical bandgaps for MgX2S4 (X = Dy, Er) are 1.70 and 1.51 eV, respectively; it shows that both are transparent to visible light. Results indicate that both materials can be suitable for spintronic and solar‐cell usage.

Compton spectroscopy of hydrogen storage material LiAlH4: Experiment and DFT strategies

Electronic structure and momentum densities of three possible phases (α, β and γ) of hydrogen storage material, LiAlH4, are reported using the linear combination of atomic orbitals (LCAO) scheme within the density functional theory (DFT). Energy bands and density of states computed using generalised gradient approximation and hybrid (Hartree-Fock + DFT) potentials show that the studied phases of LiAlH4 possess wide band gaps ranging from 3.59 to 6.64 eV. The experimental Compton profile (CP) of the most stable α-phase was measured using 100 mCi 241Am γ-ray Compton spectrometer. The experimental CP is used to validate the applicability of exchange and correlation energies by comparing it with theoretical CPs deduced using various exchange and correlation potentials. The B3LYP hybrid functional-based CP is found to be in good agreement with the present experimental Compton data. Based on Mulliken's population and valence electron charge density, the trend of ionicity is found in the descending order as γ-phase > α-phase > β-phase. Moreover, the modified Becke-Johnson (mBJ) scheme of the full potential linearized augmented plane wave (FP-LAPW) method is also used to compute the electronic and optical response of LiAlH4, which show its use as absorptive material for ultraviolet radiations. The bonding nature of the Al-H bond and Li+-[AlH4]¯ is also presented using the electron localization function.

The contribution of perennial fodder crops to the nitrogen balance of agroecosystems in Western Siberia

The article presents the results of experiments obtained in stationary experiments on the basis of grain-fallow and grain-grass crop rotations on meadow-chernozem soil in the Omsk region. The influence of spring wheat precursors (alfalfa of the 3rd year of life and fallow) on individual elements of soil fertility and crop yield has been established. It was revealed that when cultivating spring wheat by fallow in the grain-fallow crop rotation, the nitrogen balance (-28 kg/ha) is negative with an intensity of 66 %. When sowing wheat in grain-grass crop rotation on a layer of perennial grasses, the nitrogen balance is positive (+21.0 kg/ha) and the intensity is 119 %. The favorable effect of the legume component in the crop rotation on the nitrogen regime of the soil significantly increased the yield of spring wheat by 0.5 t/ha in comparison with wheat cultivated in the field crop rotation by bare fallow. Under similar conditions, studies were carried out on irrigated meadowchernozem soil in an eight-field stationary grain-grass crop rotation. The removal of nitrogen by the yield of various perennial grasses, as well as the responsiveness of alfalfa, bromus and sweet clover with productivity parameters to the level of nitrogenphosphorus nutrition, were studied. The current mobilization of nitrogen under these conditions under the vegetative brome without fertilizers was 76 kg/ha. When optimizing the phosphate regime of the soil, this indicator increased to 99 kg/ha. The removal of nitrogen by alfalfa on similar agricultural backgrounds increases due to symbiotically fixed nitrogen, by 89 and 193 kg/ha, respectively, or 2.2 and 2.9 times. Alfalfa and sweet clover responded positively to the improvement of mineral fertilizing conditions (P60N60-160). In alfalfa of the 1-5 year of life the collection of green mass and fodder units increased to 40.56 and 7.00 t/ha, respectively, or by 86 and 54 % relative to the control without fertilizers, with 82.76 GJ of exchange energy per hectare. The productivity of sweet clover of the 2nd year of life increased up to 30.85 t/ha of green mass and 2.83 t/ha of fodder units or by 37 and 17 % relative to the control.

Accurate relativistic density functional for exchange energy of atomic nuclei

The inclusion of nucleonic exchange energy has been a long-standing challenge for the relativistic density functional theory (RDFT) in nuclear physics. We propose an orbital-dependent relativistic Kohn-Sham density functional theory to incorporate the exchange energy with local Lorentz scalar and vector potentials. The relativistic optimized effective potential equations for the local exchange potentials are derived and solved efficiently. The obtained binding energies and charge radii for nuclei are benchmarked with the results given by the traditional relativistic Hartree-Fock approach, which involves complicated nonlocal potentials. It demonstrates that the present framework is not only accurate but also efficient.

Helimagnet-based nonvolatile multi-bit memory units

In this Letter, we present a design of a helimagnet-based emerging memory device that is capable of storing multiple bits of information per device. The device consists of a helimagnet layer placed between two ferromagnetic layers, which allows us to lock-in specific spin configurations. The bottom pinned layer has high anisotropy energy or stays exchange biased, which keeps its spin configuration fixed on a specific direction, while the top layer is free to rotate under the influence of in-plane magnetic fields. We begin by finding the relaxed spin structure, which is the result of the competition between the Dzyaloshinskii–Moriya interaction (DMI) and exchange energy and is referred to as the equilibrium state (“0”). The writing of a memory state is simulated by applying an in-plane field that rotates and transforms the spin configurations of the memory device. Our results indicate that stable configurations can be achieved at rotations of an integer multiple of 180° (corresponding to states “−2,” “−1,” “1,” “2,” etc.), where the anisotropy stabilizes the free layer and, thus, the exchange coupled helimagnet. These states are separated by magnetic energy barriers and intermediate, unstable spin configurations tend to revert to their adjacent states. By simply changing the direction of the field, we can achieve multi-bit data storage per unit memory cell. The maximum number of bits is reached when the anisotropy energy barriers cannot withstand the strong DMI energy. Reading can be done by evaluating the different resistance states due to the twisted spin texture.

Bioenergy Model of Plant Raw Materials and Assessment of Feed Production Technologies

It is noted that the effectiveness of the technological processes in agriculture is usually evaluated according to economic, operational and relative criteria. Such an estimate often proves to be inaccurate for solving applied problems. The functioning of the biotechnical system "operator – feed – machine – animal" reveals this discrepancy to the highest extent. The paper confirms the necessity and relevance of a fact-based analysis of energy flows in the biotechnical system, as well as the energy flows interaction with each other and with the external environment. (Research purpose) To substantiate a methodological approach to assessing the fodder production efficiency based on a bioenergetic analysis of fodder production technologies. (Materials and methods) The research involves the comparative analysis of exchange energy accumulation by plants before harvesting and the parameters of its reduction in the plant raw materials, taking into account technological impacts. (Results and discussion) It is obtained that a one-megajoule input of mechanical energy in the cultivation of cereal-grass forage mixtures provides 121 megajoules of exchange energy. The exchange energy content in the cereal-grass forage mixture is calculated to be 44,850 megajoules per hectare (1950 megajoules per ton) while the specific mechanical energy consumption amounts to 370.6 megajoules per hectare (16.1 megajoules per ton) for the feed mixture cultivation. (Conclusions) It is established that the dynamics of energy accumulation during the vegetable raw material cultivation and the character of a decrease in its energy content during fodder preparation and storage have a sustainable common trend. The growth trend of energy accumulation is proved to have a linear character for both various types of fodder crops and the decrease in the feed energy content. Efficiency assessment criteria are proposed for the mechanical energy consumption during fodder crop cultivation, plant material processing and feed storage. A mathematical model is developed making it possible to study implicit variables in a complex system of accumulation and entropy of feed exchange energy, take optimal engineering decisions to justify and improve the technologies for feed cultivation, harvesting and preparation, as well as its effective use.

Peculiarities of keeping pheasants

This research publication highlights current data on the rational use of feed protein by pheasants, which is related to the physiological needs of chicks in this essential means of nutrition. A thorough analysis of feed used in feeding pheasants at the current stage of development of pheasant breeding was carried out. It has been established that cereals have the most significant distribution. Brief information is provided on various factors affecting the composition, quality, nutritional value, and beneficial effects of the main types of grain feed obtained from different fields for pheasants. These include the technology of growing fodder crops, the composition of the soil, applied fertilizers, the type of crop, the conditions of harvesting and storage of plant products (storage period, processing and heat treatment of raw materials), etc. Features of keeping, feeding, and appropriate care of adult birds are also given. The practical advice of this publication on the specifics of feeding, exceptional care, and technology of raising young animals was considered. Brief information is provided on the general features of the rational and practical use of various protein feeds of plant origin in feeding pheasants – grains of cereal crops: corn, wheat, barley, oats, processed products of oil crops – soybeans, sunflowers, and livestock products, such as meat and eggs. In particular, the peculiarities of providing chicks with exchangeable energy and protein are described as essential indicators of the viability of the young. The practical breeding of pheasants is impossible without the correct use of protein and energy feed. It has been established that providing chicks with sufficient feed, particularly protein, is necessary for the modern technology of successful, promising, engaging, and useful pheasant farming. Suppose the conditions of keeping, care, and feeding of pheasants are violated. In that case, the incidence of disease (especially of young ones) and the survival of chicks increases, negatively affecting the efficiency of the new branch of pheasant farming. In such conditions, stress factors of the external environment, new fodder, internal factors with a sharp change in the environment, feeding, poor microclimate conditions, etc., are the factors that lead to the occurrence of diseases. Therefore, optimizing and creating comfortable conditions for keeping pheasants is an urgent task at the current stage of developing a rather exciting and rich in its subtlety industry – pheasant farming.

Comparative Review of Energy, Crude Oil, and Natural Gas for Exchange Markets in Nigeria, India and Bangladesh

In 2021, there was a global energy crisis that affected different parts of the world. In most countries, energy heavily relies on natural gas, including Nigeria, India, and Bangladesh. Several studies have explored the differences in the energy of crude oil and natural gas. Nonetheless, little effort has been made toward exploring the exportation of energy for exchange markets in Nigeria, India, and Bangladesh. This paper primarily aims at comparatively exploring the energy of crude oil and natural gas for exchange markets in the aforementioned countries. The methodology used in this paper is qualitative content analysis (QCA) and a systematical literature review (SLR) which includes various sources such as journals, the core collection of the Web of Science (WOS), oil peer review resources, and library sources. The study systematically mapped out different bibliographic materials whereby the visualization of similarities (VOS) was used to explore exchange markets for energy, crude oil, and gas in Nigeria, India, and Bangladesh. The results of the analysis indicated that, in Africa, Nigeria is regarded as the largest producer of natural gas and crude oil, with an approximation of 1.2 million barrels per day. Concerning oil and gas reserves, the country is considered the 10th and 8th largest producer in the world, having 37 billion barrels and roughly 206 trillion cubic feet, respectively. Thus, the exportation of energy is considered a central pillar of the country’s economy. In addition, India is regarded as the second largest producer of crude oil with 4.972 million barrels per day, which is approximately 5.1% of the entire world’s capacity for refining crude oil. Similarly, at the global level, India is considered the topmost consumer of crude oil, accounting for 4.8% of the world’s consumption. In the context of Bangladesh, their gas reserves account for 39.4 trillion cubic feet, and they are considered to be 70% of the commercial energy supply in the country. In conclusion, the importance of energy, crude oil, and natural gas cannot be underestimated, specifically, for the exchange import markets in the current context of the aforementioned countries. It is, therefore, suggested that the governments of Nigeria, India, and Bangladesh should strengthen their national policies on energy in order to be responsive to the global energy crisis as well as boost the exchange market in the energy sector.

ВЛИЯНИЕ МИКРОНИЗАЦИИ НА СВОЙСТВА ФУРАЖНОГО ЗЕРНА

Микронизация является одним из способов воздействия на фуражное зерно с целью повышения его усвояемости и увеличения доступности обменной энергии. Селекционные достижения и развитие технических средств делают исследование процесса микронизации актуальным. Исследования по воздействию инфракрасного излучения на фуражное зерно проводилось в течение 2020–2022 гг. Работа выполнялась в ФГБОУ ВО Вологодская ГМХА при научно-консультационной поддержке ФГБНУ ФАНЦ Северо-Востока. Исследованию подвергались сорта, возделываемые в условиях Вологодской и Кировской областей, используемые на корм крупному рогатому скоту, такие как сорт озимой ржи Волхова и сорт ярового ячменя Эколог. Источником инфракрасного излучения являлся галогеновый излучатель RxM мощностью 1500 Вт. Термографическое исследование проводилось с использованием тепловизора Testo с программным обеспечением IRSoft. Усилие разрушения зерна после микронизации определялось с помощью динамометра МЕГЕОН 04500. В качестве основного критерия оценки эффективности микронизации использовалось количество крахмала в зерне до и после микронизации при дополнительном определении усилия разрушения зерновок и количества антипитательных веществ в зерне ржи. В результате исследований установлено, что расстояние от поверхности обрабатываемого зерна до используемого источника инфракрасного излучения составляет 13 мм, что позволяет обеспечить эффективное воздействие на зерно в интервале от 20 до 40 секунд, в зависимости от вида зерна. Оптимальное время облучения зерна ржи – 30 секунд, позволяет максимально увеличить количество крахмала – на 4%, при этом снижается количество пентозанов на 0,56% и с вероятностью 95% снижается усилие разрушения зерна ржи на 9%. Оптимальное время обработки ячменя в условиях эксперимента – 40 секунд, в результате количество крахмала увеличивается на 4,4% при снижении усилия разрушения на 34%. Micronization is one of the ways to effect feeding grains in order to increase their digestibility and increase the availability of exchange energy. Selection achievements and the development of technical means make the study of the micronization process relevant. Studies on the impact of infrared radiation on feeding grains were carried out during 2020–2022. The work was carried out at the FSBEI HE Vologda SDFA with scientific and consulting support from the FSBSI FARC of the North-East. The study involved varieties cultivated in the conditions of the Vologda and Kirov regions used for cattle feed, such as winter rye variety Volkhova and spring barley variety Ecolog. The source of infrared radiation was a 1500 W RxM halogen emitter. The thermographic study was conducted using a Testo thermal imager with IRSoft software. The grain destruction force after micronization was determined using a MEGEON 04500 dynamometer. The primary criterion for evaluating micronization efficiency was the amount of starch in the grain before and after micronization in the additional determination of the grain destruction force of caryopses and the amount of anti-nutrient substances in the rye grain. As a result of studies, it was found that the distance from the surface of the processed grain to the used infrared radiation source is 13 mm, which makes it possible to provide an effective effect on the grain in the range of 20 to 40 seconds, depending on the type of grain. The optimal irradiation time of rye grains is 30 seconds, it allows maximizing the amount of starch – by 4%, while reducing the amount of pentosans by 0.56% and with a probability of 95% the rye grain destruction force is reduced by 9%. The optimal processing time of barley under experimental conditions is 40 seconds, as a result, the amount of starch increases by 4.4% with a decrease in the destruction force by 34%.