bluuebunny/crossref_metadata_2025 huggingface dataset:
Cu(OTf)2/TBHP/O2-Mediated Tandem Oxidative Reaction: Easy Access to Benzopyrano[4,3-b]pyridines
Authors: Cheng Dongping , Li Jing-Hua , Xu Xiaoliang , Yang Hongjiao , Xia Hongshuang , Gu Huafang
Published: March 2023

An effective tandem reaction of 4-aminocoumarins and 1,3-diarylpropenes mediated by Cu(OTf)2/TBHP (tert-butyl hydroperoxide)/O2 that provides various benzopyrano[4,3-b]pyridines in moderate to good yields is disclosed. The reaction proceeds through oxidative coupling, intramolecular cyclization, and dehydro-aromatization. This approach has the advantages of high atom-economy, environmental compatibility, and wide substrate scope.
Synthesis of Triarylphosphines via Cu-Catalyzed Coupling of Aryl Halides and Acylphosphines
Authors: Zhu Hong , Wang Zhiqian , Xu Minghui , Zhu Zhengping , Yi Haojie
Published: March 2023

A Cu-catalyzed C(sp2)–P bond forming reaction using an acylphosphine as the phosphorus source is reported; with CuCl2 as the catalyst, 34 examples of aryl iodides and bromides were converted into triarylphosphines in good to excellent yield. A preliminary study of the mechanism was carried out and found that a radical intermediate is not involved. This reaction is an extension of the application of acylphosphines in Cu-catalyzed reactions and shows their potential as a phosphination reagent in the synthesis of tertiary phosphines.
Post-COVID-19 Inappropriate Sinus Tachycardia Treated with Naja tripudians: A Case Report
Authors: Arora Amit , Kumar Udesh , Shukla Dhananjay Kumar
Published: March 2023

Background/Introduction The majority of people who recover from coronavirus disease 2019 (COVID-19) experience tachycardia and/or palpitations after slight activity or at rest. In some cases, the resting heart rate may remain above 100 beats per minute or get exacerbated out of proportion by slight activity. This persistent tachycardia appearing in post-COVID-19 may clinically present as inappropriate sinus tachycardia (IST). The common mode of diagnosis is electrocardiography after excluding other causes of tachycardia. So far, there is no reported study evaluating individualised homoeopathic intervention in post-COVID-19 IST in peer-reviewed homoeopathic journals.

Method This report describes a case of tachycardia and palpitations developed after COVID-19. After complete evaluation of laboratory reports and clinical examination, the diagnosis of IST was made. After detailed case taking and repertorisation, Naja tripudians was prescribed as an individualised homoeopathic remedy to treat the case. Outcomes were assessed objectively on the basis of electrocardiography and subjectively using outcome related to impact on daily living (ORIDL) scale.

Result There was a marked subjective improvement along with objective improvement as evidenced by electrocardiography images. The case showed a 4+ outcome on ORIDL scale. The Modified Naranjo Criteria total score was +9 out of a possible +13, providing definite evidence to attribute the clinical outcome with the homoeopathic intervention.

Conclusion This single case demonstrates that Naja tripudians, a rarely used drug, may be helpful in treating post-COVID-19 IST. Clinical trials in this direction are required to conclude firm causal attribution.
An Illustrative Case of Bilateral Internal Carotid Artery Occlusion Concomitant with Aneurysm of the Obstructed ICA Reconstituted via Collaterals: Emphasizing the Role of Rescue Collaterals in Decision-Making
Authors: Malikov Azad , Sayin Bige , Akmangit Ilkay , Senol Yigit Can , Daglioglu Ergun , Belen Ahmet Deniz
Published: March 2023

In patients with bilateral internal carotid artery (ICA) obstruction, the basilar and ophthalmic arteries become the most critical arteries for brain perfusion, and the location of aneurysm formation may be associated with increased wall shear stress induced by compromised carotid circulation. Consideration of collateral routes may have an impact on therapeutic decisions for patients undergoing extracranial to intracranial (EC-IC) bypass and aneurysm surgery. We report a rare case of a young woman with bilateral ICA occlusion simultaneous with dissecting aneurysm of the obstructed ICA reconstituted via collaterals, emphasizing the functional value of collaterals and therapeutic strategy. We present a young woman with angiographic evidence of cerebrovascular early atherosclerotic disease. A young patient was found to have bilateral ICA occlusion and dissecting aneurysm of the obstructed ICA. A large fusiform aneurysm was clipped. Then, an anastomosis was performed from the left superficial temporal to the M3 segment of the middle cerebral artery. The patient's postoperative course was uneventful, and she was discharged to rehabilitation with no residual sequelae. This case illustrates a rare case of bilateral ICA occlusions, presented with robust collaterals, and dissecting aneurysm of the obstructed ICA reconstituted via collaterals. We also demonstrate excellent surgical clipping of a challenging ICA aneurysm and cerebral bypass surgery.
Cerebellar Ischemic Stroke Secondary to Rotational Non-Dominant Vertebral Artery Occlusion (RVAO): A Rare Complication Following Supratentorial Surgery
Authors: Bono Beatrice C , Riva Marco , Pessina Federico
Published: March 2023

Non-traumatic vertebrobasilar stroke syndrome is rare. Many etiological mechanisms have been described over the years, with the dynamic occlusion of one vertebral artery following head rotation (RVAO) being one of them. We report the case of a patient undergoing surgery for supratentorial metastasis, who postoperatively developed a cerebellar ischemic stroke secondary to RVAO. Postoperative imaging showed a right hypoplastic VA; so, a transient occlusive mechanism was thought to be responsible for the postoperative cerebellar stroke. Although rare, RVAO can occur following head rotation during patient positioning for neurosurgical procedures.
Spin–lattice relaxation time in water/graphene-oxide dispersion
Authors: De Thomasis G. , Galante A. , Fioravanti G. , Ottaviano L. , Alecci M. , Profeta G.
Published: March 2023

We present the results of the calculations of the spin–lattice relaxation time of water in contact with graphene oxide by means of all-atom molecular dynamics simulations. We fully characterized the water–graphene oxide interaction through the calculation of the relaxation properties of bulk water and of the contact angle as a function of graphene oxide oxidation state and comparing them with the available experimental data. We then extended the calculation to investigate how graphene oxide alters the dynamical and relaxation properties of water in different conditions and concentrations. We show that, despite the diamagnetic nature of the graphene oxide, the confining effects of the bilayers strongly affect the longitudinal relaxation properties of interfacial water, which presents a reduced dynamics due to hydrogen bonds with oxygen groups on graphene oxide. This property makes graphene oxide an interesting platform to investigate water dynamics in confined geometries and an alternative contrast-agent for magnetic resonance imaging applications, especially in view of the possibility to functionalize graphene oxide from theranostic perspectives.
Ensuring thermodynamic consistency with invertible coarse-graining
Authors: Chennakesavalu Shriram , Toomer David J. , Rotskoff Grant M.
Published: March 2023

Coarse-grained models are a core computational tool in theoretical chemistry and biophysics. A judicious choice of a coarse-grained model can yield physical insights by isolating the essential degrees of freedom that dictate the thermodynamic properties of a complex, condensed-phase system. The reduced complexity of the model typically leads to lower computational costs and more efficient sampling compared with atomistic models. Designing “good” coarse-grained models is an art. Generally, the mapping from fine-grained configurations to coarse-grained configurations itself is not optimized in any way; instead, the energy function associated with the mapped configurations is. In this work, we explore the consequences of optimizing the coarse-grained representation alongside its potential energy function. We use a graph machine learning framework to embed atomic configurations into a low-dimensional space to produce efficient representations of the original molecular system. Because the representation we obtain is no longer directly interpretable as a real-space representation of the atomic coordinates, we also introduce an inversion process and an associated thermodynamic consistency relation that allows us to rigorously sample fine-grained configurations conditioned on the coarse-grained sampling. We show that this technique is robust, recovering the first two moments of the distribution of several observables in proteins such as chignolin and alanine dipeptide.
Molecular phylogeny of the snorkel snail Rhiostoma housei, a species complex from Thailand with descriptions of three new species
Authors: Prasankok Pongpun , Sutcharit Chirasak , Jeratthitikul Ekgachai , Backeljau Thierry , Pimvichai Piyatida
Published: March 2023

Snorkel snails (genus Rhiostoma) are widely distributed in Indo-China and on the Malay Peninsula. The shell morphology is traditionally used for species identification yet in Thailand, the common snorkel snail, Rhiostoma housei, shows considerable variation in shell morphology within and between populations. Therefore species identifications and delimitations are difficult. We used two mitochondrial DNA fragments (COI and 16S rRNA) and morphological characters to delimit species and infer phylogenetic relationships of Rhiostoma housei s.l. from eight localities in Thailand, representing potential cryptic species suggested by earlier allozyme and karyological data. Results revealed four distinct clades from different geographic areas in Thailand. Species delimitation analyses confirmed the clades as four separate species and a geometric morphometric analysis demonstrated subtle but consistent conchological differences between the four clades. The high COI sequence divergences among the four clades (mean: 14.8%; range: 10.3–16.5%) further supported the species level recognition. As a consequence, three new species are described from Thailand: R. khoratense, sp. nov., R. nakwangense, sp. nov. and R. phunangense, sp. nov. ZooBank: urn:lsid:zoobank.org:pub:EE534749-9346-4972-BF2E-3B5D0EB8AED8
Dissipation and energy propagation across scales in an active cytoskeletal material
Authors: Foster Peter J. , Bae Jinhye , Lemma Bezia , Zheng Juanjuan , Ireland William , Chandrakar Pooja , Boros Rémi , Dogic Zvonimir , Needleman Daniel J. , Vlassak Joost J.
Published: March 2023

Living systems are intrinsically nonequilibrium: They use metabolically derived chemical energy to power their emergent dynamics and self-organization. A crucial driver of these dynamics is the cellular cytoskeleton, a defining example of an active material where the energy injected by molecular motors cascades across length scales, allowing the material to break the constraints of thermodynamic equilibrium and display emergent nonequilibrium dynamics only possible due to the constant influx of energy. Notwithstanding recent experimental advances in the use of local probes to quantify entropy production and the breaking of detailed balance, little is known about the energetics of active materials or how energy propagates from the molecular to emergent length scales. Here, we use a recently developed picowatt calorimeter to experimentally measure the energetics of an active microtubule gel that displays emergent large-scale flows. We find that only approximately one-billionth of the system’s total energy consumption contributes to these emergent flows. We develop a chemical kinetics model that quantitatively captures how the system’s total thermal dissipation varies with ATP and microtubule concentrations but that breaks down at high motor concentration, signaling an interference between motors. Finally, we estimate how energy losses accumulate across scales. Taken together, these results highlight energetic efficiency as a key consideration for the engineering of active materials and are a powerful step toward developing a nonequilibrium thermodynamics of living systems.
Data-driven discovery of electron continuity equations in electron swarm map for determining electron transport coefficients in argon
Authors: Kawaguchi S , Takahashi K , Satoh K
Published: March 2023

In this study, we develop a novel method for determining electron transport coefficients from electron swarm maps measured by a scanning drift-tube experiment. In our method, two types of electron continuity equations that describe either the spatial or the temporal evolution of an electron swarm are discovered in the electron swarm map. The electron transport coefficients can be determined from the coefficients in the discovered equations. Therefore, we can determine the Townsend ionization coefficient, ionization rate coefficient, center-of-mass drift velocity, mean arrival-time drift velocity, longitudinal diffusion coefficient, and longitudinal third-order transport coefficient. These transport coefficients in argon are determined over a wide range of reduced electric fields, E/N, from 29.7 to 1351.6 Td (1 Td = 10−21 Vm2) using our method. We establish that the consideration of high-order transport coefficients, which have been systematically ignored so far, is important for the proper determination of low-order transport coefficients, specifically the electron drift velocity and longitudinal diffusion coefficient, in the presence of ionization growth.
Wavelet packet energy-based damage detection using guided ultrasonic waves and support vector machine
Authors: Lyu Yetao , Yang Jianwei , Ge Ming , Xu Lei
Published: March 2023

Substantial work has shown that the modulation of structural damage on probing guided ultrasonic waves can result in wave components corresponding to different frequencies, causing wave energy transfer from central frequency to other frequency bands. To make use of the damage-induced wave energy transfer in different frequency bands, a data-driven method which combines wavelet packet decomposition (WPD), principal component analysis (PCA) and support vector machine (SVM), is proposed in this study for structural damage identification in both metallic and composite materials. Firstly, WPD is employed to decompose the original signal into different frequency bands, based on which the wave energy at each frequency band can be determined. A wave energy distribution vector is constructed according to the energy proportion of each frequency band. Then, PCA is recalled conducting dimensionality reduction for the energy distribution vectors, in order to improve the computational efficiency for subsequent SVM classification. The compressed energy distribution vectors are used as the input to train an SVM-based classifier for identifying structural damage. To validate the proposed WPD-PCA-SVM method, experiments are performed on both aluminum plate and glass fiber reinforced polymer (GFRP) laminate. According to the experimental results, the embryonic fatigue crack in the (aluminum) plate and the anomaly in the GFRP laminate can be identified by the proposed method, with a detection accuracy of 92.86% for aluminum plate and 95.45% for GFRP laminate, respectively, demonstrating the effectiveness of the proposed method for damage detection in both metallic and composite materials.
Hierarchies of critical points of a Landau-de Gennes free energy on three-dimensional cuboids
Authors: Shi Baoming , Han Yucen , Yin Jianyuan , Majumdar Apala , Zhang Lei
Published: March 2023

We investigate critical points of a Landau–de Gennes (LdG) free energy in three-dimensional (3D) cuboids, that model nematic equilibria. We develop a hybrid saddle dynamics-based algorithm to efficiently compute solution landscapes of these 3D systems. Our main results concern (a) the construction of 3D LdG critical points from a database of two-dimensional (2D) LdG critical points and (b) studies of the effects of cross-section size and cuboid height on solution landscapes. In doing so, we discover multiple-layer 3D LdG critical points constructed by stacking 2D critical points on top of each other, novel pathways between distinct energy minima mediated by 3D LdG critical points and novel metastable escaped solutions, all of which can be tuned for tailor-made static and dynamic properties of confined nematic liquid crystal systems in 3D.
Accelerated partial separable model using dimension-reduced optimization technique for ultra-fast cardiac MRI
Authors: Li Zhongsen , Sun Aiqi , Liu Chuyu , Wei Haining , Wang Shuai , Fu Mingzhu , Li Rui
Published: March 2023

Objective. Imaging dynamic objects with high temporal resolution is challenging in magnetic resonance imaging (MRI). The partial separable (PS) model was proposed to improve imaging quality by reducing the degrees of freedom of the inverse problem. However, the PS model still suffers from a long acquisition time and an even longer reconstruction time. The main objective of this study is to accelerate the PS model, shorten the time required for acquisition and reconstruction, and maintain good image quality simultaneously. Approach. We proposed to fully exploit the dimension-reduction property of the PS model, which means implementing the optimization algorithm in subspace. We optimized the data consistency term and used a Tikhonov regularization term based on the Frobenius norm of temporal difference. The proposed dimension-reduced optimization technique was validated in free-running cardiac MRI. We have performed both retrospective experiments on a public dataset and prospective experiments on in vivo data. The proposed method was compared with four competing algorithms based on the PS model and two non-PS model methods. Main results. The proposed method has robust performance against a shortened acquisition time or suboptimal hyper-parameter settings, and achieves superior image quality over all other competing algorithms. The proposed method is 20-fold faster than the widely accepted PS+sparse method, enabling image reconstruction to be finished in just a few seconds. Significance. The accelerated PS model has the potential to save a great deal of time in clinical dynamic MRI examinations and is promising for real-time MRI applications.
A review of superconductivity in nanostructures—from nanogranular films to anti-dot arrays
Authors: Bose Sangita
Published: March 2023

Superconductivity in small particles has been studied since the early sixties. A large number of sample geometries for both one component elemental superconductors and dual component nano-composites having elemental superconducting particles dispersed in a non-superconducting matrix have been explored which has helped us to understand the mechanism of the evolution of the superconducting transition temperature (T
c) with decreasing particle size. In this article, we review the work done on nanostructured superconductors from nanogranular films to these dual component superconducting nano-composites. In addition, we also present the experimental work done on another nanostructured system, the superconducting films with periodic arrays of nano-sized holes, showing the interesting property of the vortex matching effect and we try to understand the dominant mechanism for this phenomena.
Optoelectronic properties of RuCrX (X = Si, Sn, Ge) Half Heusler alloys: a DFT study
Authors: Shah Syed Tauseef Hussain , Almalki Ahmed M , Sagar Sadia , Mustafa Ghulam , Bahadar Ali , Hossain Nazia
Published: March 2023

The aim of this study was to investigate the structural, electronic, optical, and thermal properties of optoelectronic Half Heusler Alloys, RuCrX (X = Si, Sn, Ge). The characterizations of these Half Heusler Alloys, RuCrX (X = Si, Sn, Ge) have been performed using Density Functional Theory (DFT) through first-principles calculations with the aid of WIEN2K code. The Generalized Gradient Approximation (GGA) was utilized as an exchange-correlation function in WIEN2K-Package to optimize the structures.. To obtain the necessary observational quality and desired properties, Full Potential Linearized Augmented Plane Wave (FPLAPW) was applied. The calculation of the lattice constants and band gaps was crucial to determine suitable materials for specific optoelectronic applications. This study also emphasized the complex dielectric function and elastic properties leading to the imaginary part of the dielectric functions showed that compounds were optically metallic and transparent with ductile properties. Also, the optical spectra and band structure transitions were studied in detail. Hence, the study predicted that Half Heusler Alloys, RuCrX (X = Si, Sn, Ge), have the potential for applications in optoelectronic devices.
Novel propagation phenomena: behaviors of local trend imitation on multiple limited contact networks
Authors: Zhu Xuzhen , Liu Siyuan , Tian Yang
Published: March 2023

The local trend imitation(LTI) feature behavior has been deeply studied on specific complex networks, but it still needs to be explored in more scenarios. In fact, the multiple networks with individual limited contact feature is more in line with the real scenario. On the multiple limited networks, a novel model is proposed to investigate the effects of individual contact capacity heterogeneity. Then,information propagation mechanism is then measured and examined using a developed partition theory. The experimental results show crossover occurrences of phase transition. In the new network model, the final spreading scope exhibits a second-order continuous growth when individuals display a positive LTI behavior. Individuals have a passive LTI behavior, however, the final spreading scope exhibits a first-order discontinuous growth. Besides, a greatest ultimate spreading size appears at an ideal LTI parameter with the unit spreading probability changing. Additionally, individual contact capacity heterogeneity changes the rate of information spreading and the global adoption pattern. Eventually the outcomes of the theoretic analysis match those of the simulations.
Synergy of porous and air-gap structures for pressure sensing arrays with high sensitivity and wide detection range towards machine learning-assisted gait analysis
Authors: Zhang Wanli , Zhou Zaiwei , Chen Shiqi , Zhang Yue , He Bingwei
Published: March 2023

A smart insole based on pressure sensing arrays is a simple and effective means of gait analysis assist in the assessment of human movement and neurological health. However, these smart insoles usually fail to combine high sensitivity with a wide detection range, making them only suitable for people within a certain body weight range. Here, based on the synergy of porous and air-gap structures, we develop a high-performance and high stability smart insole, which has a sensitivity of up to 16.064 kPa−1 in a wide pressure range of 0.170 Pa to 248 kPa. After combined with Decision Tree machine learning model, gait classification and recognition can be as high as 99.96%. Based on these, a tap dance game was designed, which proves its ability to identify individual activities, and demonstrates its potential of application in the field of human-computer interaction and medical engineering.
Coalgebra symmetry for discrete systems
Authors: Gubbiotti G , Latini D , Tapley B K
Published: March 2023

In this paper we introduce the notion of coalgebra symmetry for discrete systems. With this concept we prove that all discrete radially symmetric systems in standard form are quasi-integrable and that all variational discrete quasi-radially symmetric systems in standard form are Poincaré–Lyapunov–Nekhoroshev maps of order N − 2, where N are the degrees of freedom of the system. We also discuss the integrability properties of several vector systems which are generalisations of well-known one degree of freedom discrete integrable systems, including two N degrees of freedom autonomous discrete Painlevé I equations and an N degrees of freedom McMillan map.
Classical triangular lattice antiferromagnetic Ising model as a free-fermion/superconductor system
Authors: Nourhani Amir , Crespi Vincent H , Lammert Paul E
Published: March 2023

We present a treatment of the triangular lattice antiferromagnetic Ising model (TAFIM) based on a small number of elementary ideas common to statistical and solid-state physics. The TAFIM is represented as a reduced BCS model in one space, one (imaginary) time dimension. The representation is approximate for nonzero temperature, but allows quick derivation of asymptotically exact thermodynamic functions, and the divergence of the spin–spin correlation length. The fermionic representation is exact at zero temperature. We demonstrate the existence of a two-dimensional continuum of zero-temperature equilibrium macrostates characterized by satisfied bond fractions of the three different orientations, and calculate their entropy densities.
Climate changes analysis in the Volga Region and the Urals
Authors: Nesterenko Yu M , Solomatin N V , Nikiforov S E , Yu Nesterenko M , Kapustina O A
Published: March 2023

The article analyzes the changes in annual air temperatures and precipitation in 13 cities of the Volga region and the Urals of Russia and reveals differences in the rates of climate change over time and by seasons in the forest and steppe zones. In the studied regions, on average in 1887-2020, based on 100 years, the annual air temperature increased by 1.8 °C, winter by 2.3 °C and summer by 1 °C. It increases 20% faster in the steppe zone. On average, in the forest and steppe zones during this period, annual precipitation increased by 55 mm mainly due to winter precipitation.
Model of a stationary thermal detonation wave in the “liquid lead – water” system for safety analysis of NPP with the reactor BREST-OD-300 during heat exchanger tube break accident
Authors: Melikhov V I , Melikhov O I , Saleh B
Published: March 2023

This paper presents a mathematical model of a stationary wave of thermal detonation in the “liquid lead - water” system, which can occur after the rupture of a steam generator tube of the reactor BREST-OD-300. The model is based on the mechanics of multiphase fluid flows. The system under study includes a continuous phase of liquid lead, in which drops of water surrounded by a steam film are dispersed. Heat exchange between high-temperature molten lead and water drops is carried out in the film boiling mode. A shock wave propagating in this multiphase system causes all phases in motion. Due to the significant difference in density between liquid lead and water, a difference in velocities arises between dispersed water drops and liquid lead, which cause the fragmentation of water droplets. The shock wave velocity and amplitude are determined by constructing the shock adiabat and the Hugoniot adiabat for the parameters of the studied multiphase mixture. To describe the fragmentation of water droplets, heat transfer between phases, and interfacial friction, the empirical correlations of the thermal detonation theory are used. The obtained numerical solutions describe the distributions of parameters in the zone of melt – water interaction.
The influence of a noncondensable gas on the collapse of a bubble in a stratified steam explosion at NPP
Authors: Melikhov V I , Melikhov O I , Yakush S E , Saleh B
Published: March 2023

In the present work, the effect of a noncondensable gas on the collapse of a hot bubble in cold water was studied. It is assumed that the bubble consists of a gas mixture of steam, which can condense on cold water, and a noncondensable gas. The dynamics of the bubble was modeled by the integral equations of mass and energy supplemented by the steam diffusion equation. The steam condensation rate was determined by heat fluxes on the interfacial surface from the steam and water sides. It was used a one-dimensional spherically symmetric approach. The water surrounding the bubble was considered as an incompressible fluid, the flow of which was described by the Rayleigh-Plesset. Heat transfer in water is described by a one-dimensional heat equation, which takes into account conductive and convective mechanisms of heat transfer. Calculations performed using this model showed that the presence of a noncondensable gas in a bubble does not significantly affect its collapse in cold water. This means that the noncondensable gas cannot significantly weaken the impact of water on the melt, which occurs when a bubble collapses near the interface, which leads to a stratified steam explosion.
Influence of nanoscale objects on grain processing: results of mashing in the presence of Al2O3 nanoparticles
Authors: Karpenko D V , Tsyganova V V , Nasedkin A S , Artemeva V S
Published: March 2023

The article considers the influence of nanoscale objects on grain raw materials processing on the example of beer wort preparation. The effect of aluminum oxide nanoparticles present in the mash on the first wort indicators (concentration of dry and reducing substances, amine nitrogen) obtained by infusion or single-decoction mashing was studied. It was revealed that the influence of Al2O3 nanoparticles depends on their concentration, the object of influence and the method of preparation of beer (first) wort. The most sensitive to the presence of aluminum oxide nanoparticles under the experimental conditions were saccharifying hydrolases of grain raw materials. That caused the greatest fluctuations in the concentrations of reducing substances in the test samples of the first wort. Nanoparticles had the least pronounced effect on grain proteases, as a result fluctuations in the concentration of amino acid nitrogen in the experimental variants of the first wort were the smallest. When obtaining beer wort by the infusion method, the effect of nanoparticles was more pronounced than in single-decoction mashing. The concentrations of aluminum oxide nanoparticles were revealed, the excess of which led to a significant deterioration in the controlled parameters of the first wort - 1.5-2 mg/cm3, depending on the method of mashing.
Short-Term Electrical Load Forecasting Based on Neural Networks
Authors: Kuantayev N , Bainiyazov B A , Uakhitova A B
Published: March 2023

The article sets out the use of an artificial neural network for electrical load consumption forecasting. Electrical load prediction is one of the most demanded areas of research in the electric power industry. The two-layer artificial neural network of direct distribution with the number of neurons in the hidden layer equal to 6 was proposed in the article. The following data was taken as an input for forecasting short-term electrical load: electrical load, time, day of the week, temperature, day, weekend and working day code. According to the studies, the value of the mean absolute percentage error was 2.35, using the Bayesian Regularization learning algorithm.
To calculation of basic parameters of the drum-type root crop grinder
Authors: Ayugin N P , Morozov A V , Ulyanov M V , Kalimullin M N , Vasiliev A O , Fomenko N L
Published: March 2023

The article is devoted to the study of the root crop grinder, its design and design features are presented.The calculation of the forces which act upon the crushed feed during operation of the developed grinder was carried out. Formulae for calculation of geometric dimensions of the drum of the grinding unit, the hopper and the cutting elements are given, as well as the throughput capacity of the grinder. The research results can be used for development of root crop grinders which prepare root crops for feeding of farm animals.
To the study of the vibration in an acoustic medium with coating excited by a concentrated harmonic source
Authors: Pavlova A V , Rubtsov S E , Telyatnikov I S
Published: March 2023

When monitoring dangerous geodynamic processes, it is topical to study wave fields on the surface of geological structures and, since on the scale of the Earth’s structure, lithospheric plates can be considered as coatings of small thickness, a plate is accepted as the simplest model of an extended lithospheric one. The paper considers the problem of the plate oscillations on the surface of an acoustic layer, excited by the effect of a concentrated harmonic source located in an acoustic medium. The solution is built using an integral approach well developed for similar problems arising in geophysics, seismoacoustics and ecology. Integral representations of the amplitude values for the stress on the lower boundary of the coating and the surface displacements of the structure under consideration are obtained.
Height-Diameter fixed effects models for the pine in European Russia
Authors: Dubenok N N , Lebedev A V , Gostev V V , Gemonov A V , Gradusov V M
Published: March 2023

The purpose of the study is to select and justify a regression model that will most accurately reflect the dependence of heights on the diameters at breast height of pine plantations in the European part of Russia. 28 height-diameter models were selected based on literary sources and tested for research. Näslund’s equation is justified as the best model for the relationship between height and diameter at chest height. It can be applied in practice when performing forestry and research work in pine forests of the European part of Russia.
Natural resources and rational nature management as one of the aspects of sustainable development of the territory
Authors: Ermakova A M
Published: March 2023

The article deals with natural resources, their organization and rational use from the point of view of ensuring the ecological sustainability of territories. The effective use of natural monuments will create the necessary favorable background for the territories and the life of the population.
Current state and development trends of hydrogen technologies
Authors: Egorov A N , Shaituro M I , Moskalenko A B
Published: March 2023

The article analyzes the current state of research and development in the field of production, storage and use of hydrogen fuel. It was revealed that the most environmentally friendly method is the hydrogen production by electrolysis based on nuclear power. At the same time, in Russia, the development of hydrogen energy is a priority in the energy sector in general and nuclear energy in particular. Specific investment in electrolyzers with a solid polymer membrane is about 3100-2050 $/kW. By 2030, the cost is predicted to be $950/kW and $740/kW for electrolysis with proton-exchange and alkaline electrolyte, respectively. To store hydrogen, research is being carried out mainly on the metal hydride method, as well as gaseous compressed in special high-strength composite tanks under pressure up to 100 MPa and in large-volume underground tanks. The use of hydrogen fuel for power generation is planned mainly on the basis of fuel cells and micro gas turbines. The average cost of a power plant based on solid oxide fuel cells in 2020 amounted to 1720-1430 $/kW. By 2035 and 2050, $960/kW and $770/kW respectively are predicted. A promising area of development in the field of fuel cells is reversible fuel cells.
On the balance between the preservation of natural complexes and the intensity of recreational and tourist activity (by the example of natural monuments of regional importance in the Samara Region, Russia)
Authors: Ilyina V N , Mitroshenkova A E , Kozlovskaya O V , Kazantsev I V , Belyaeva Yu V
Published: March 2023

The article presents the authors’ expert opinion on the use of specially protected natural areas in the rank of natural monuments of regional importance in the Samara Region (Russia) as recreational and tourist sites. The absence of the necessary organization and regulation of tourist and recreational activities in most areas, spontaneity and mass recreation, and as a consequence, the loss of the natural characteristics of some natural complexes is emphasized here. In the course of work, methods of biodiversity assessment were used and the current state of ecosystems of 7 protected areas was determined.
Cultivation of fodder beans at the Zarechny state farm during the development of virgin lands in Kazakhstan
Authors: Mazhitova Zh S , Khassenova Zh O , Issayev A U
Published: March 2023

The article deals with the beginning of virgin lands development in Kazakhstan in the 1950s. In those years there was an acute shortage of fodder crops, as vast areas of land were given to grain crops. Since the traditions of legume and fodder crops cultivation were forgotten, the specialists of the Zarechny state farm had to apply new methods to solve fodder problems under difficult conditions. The authors came to the conclusion that during the experiments, the specialists of the state farm determined the best way of sowing forage beans by means of square-breeding sowing of a mixture of corn and beans. The chosen method solved the problem of fodder for cattle to a certain extent, affecting the productivity of the dairy herd and its weight gain.
Improving the efficiency of creating a mole irrigation system in the Lower Volga region
Authors: Khodiakov E A , Milovanov S G , Bondarenko K V
Published: March 2023

The article presents the results of research in the Lower Volga region on the development of working bodies for the installation of mole sprinklers in the soil (soil pipes for supplying water to plants). This method of irrigation, as the main type of subsoil irrigation of agricultural crops, is used in this region for the first time. In field experiments, 3 options for the design of expanders were studied, as the main elements of molehills for the formation of mole drains. These were expanders combining a cone and a cylinder (cone-cylindrical); truncated cone and paraboloid (cone-parabolic form) and vice versa, paraboloid and truncated cone (parabolic form). Each form differed by 3-4 lengths of the main part of the body and diameters. The conducted studies showed that among the three considered forms of expanders, the cone-parabolic one turned out to be the most effective, since the degree of safety of the molehills here was the highest. With a cutting depth of 0.45 … 0.50 m, the degree of shedding of the walls decreased with an increase in the diameter of molehills more than 50 mm, reaching the best results for mole irrigators with a diameter of 70 mm. Comparison of different lengths showed that molehills are formed most effectively when using 380 mm long expanders. The results obtained will be used in 2023. to create an effective mole irrigation system for technical (on the example of cotton) and leguminous crops (on the example of soybeans).
Problems of digital transformation in agriculture and instruments of state support
Authors: Beksultanova A I , Dzhankhotova P M , Shardan S K
Published: March 2023

The article systematizes global trends in the spread of digital technologies in the field of agriculture. Quantitative estimates of the parameters of the development of digital technologies in agriculture in the period 2019-2021 are presented on the basis of data from the federal statistical observation, as well as monitoring of the digital maturity. The purpose of this article is to identify problematic issues of the introduction of digital technologies in agriculture in Russia, to show the current situation for the introduction and use of digital technologies in agriculture, as well as to give recommendations on measures of state policy of digital transformation of agriculture in the current conditions.
Condition of pine and larch forests adjacent to the reservoir within the Sayano-Shushensky Nature Reserve
Authors: Tatarintsev A I , Mikhaylov P V , Demidko D A , Kulakov S S , Melnichenko N P
Published: March 2023

Forests cover 60% of the Sayano-Shushensky Nature Reserve, 48% of which are larch and pine stands. The purpose of the research was to assess condition of Larix sibirica Ledeb. and Pinus sylvestris L. forests adjacent to the reservoir within the reserve. We conducted forest pathological inspection (for each species on four research plots), an integral assessment of the stands condition, macroscopic diagnostics and disease manifestations indicators estimation and studied model trees affected by xylophagous insects. Studied stands ranged from sustainable to ones with disturbed sustainability and their health status ranged from healthy to varying degrees of weakening. One of the main factors weakening forest stands were ground fires, leading to increased mortality of small-diameter trees that are less resistant to heat stress (most typical of P. sylvestris). Medium and large diameter trees post-fire mortality in L. sibirica forest stands was due to the Zeiraphera griseana feeding, and in relatively flat coastal areas due to repeating flooding. The presence of groups of trees dying from the top down were observed in pine forests growing on thin soils most likely due to an imbalance between the amount of required and available soil moisture. Diseases were not common and did not have a significant impact on the forest stands. Potentially harmful are the following diseases: in larch forests - European larch canker (pathogen - Lachnellula willkommii), in pine forests - Scots pine blister rust (pathogen - Cronartium pini). Xylophagous insects (dominated by Ips acuminatus) had an increased abundance and fed on dying trees in pine forests weakened after fires.
The potential of unclaimed forest resources of the Krasnoyarsk Territory and the prospects for their use
Authors: Dolmatov S N , Pryanichnikova A V , Tikhonov E A , Zagidullin R R , Sabitov L S , Yumagulova V M , Sokolova VA
Published: March 2023

The timber industry is one of the oldest industries in Russia, associated with the harvesting and processing of wood. It is responsible for the stock of wood, its removal, primary processing and waste disposal. On the territory of the country there is 1/4 of all the world’s timber reserves, the volume of timber harvesting is estimated at hundreds of millions of cubic meters. An integral part of the logging process is the generation of waste, the volume of which is directly related to the volume of logging operations. Every year in the Russian Federation, 35.5 million m³ of wood waste is generated, which worsens the ecological situation. Forest fires and insect pests are also one of the main causes of the weakening and death of forests. Areas with abandoned wood, affected plantings require priority development, and low-quality wood should be recycled to obtain recyclable materials. The introduction of resource-saving, environmentally friendly and efficient technology, which provides for the processing of waste and the use of secondary raw materials, will help minimize the negative impact of unclaimed wood on the environment.
Water stress tolerance of several newly derived breadfruit cultivars
Authors: Martirosyan H , Nikkhahkouchaksaraei H , Sadoyan R , Avetisyan A
Published: March 2023

To evaluation of several wild wheat and barley genotypes in response to water deficit stress, experiments were laid out in randomized complete block design with three replicates in optimal and stress condition environment for three years. Data analysis showed a significant genetic diversity within genotypes in terms of grain yield, and the existence of significant genotype × environment interaction, made it possible to analyze data for genotypes stability to environment in this study. The stability analysis showed that Garni (an emmer variety) was recognized as the most stable genotype to water deficit stress with a high grain yield. The stress tolerance tests also found that the Garni genotype is more tolerant to water deficit stress than other genotypes. Based on the results obtained, Garni genotype was recognized as a stable genotype and the most tolerant genotype to water deficit stress that has a high grain yield, and it can be used as a crossbreeding parent in wheat breeding.
Design of a small-scale wind tunnel for the study of horizontal-axis wind turbine blades
Authors: Pankratov E V , Kangash A I , Kosarev I A , Maryandyshev P A
Published: March 2023

The paper considers the details of design and construction of a small-sized wind tunnel with an open circuit and a closed test section for investigating the blades of horizontal-axis wind turbines. The effect of different types of jet straighteners on the turbulence of the flow in the test section has been studied. Turbulence flow distributions Tu at Reynolds numbers Re from 5·103 to 2·104 are obtained using Laser Doppler Anemometry methods. As a result, the wind tunnel design with average flow turbulence of 1.6 % is obtained. The flow visualization of NACA 64-618 airfoil at Re = 5·103 is obtained.
An evaluation on mechanical properties of vaccum bagging processed kenaf epoxy nano aluminium oxide and nanographene composites
Authors: Taj Amreen , R P Swamy , Naik Kishan , K N Bharath
Published: March 2023

This paper aims to study the mechanical properties of hybrid polymer composites and the addition of primary and secondary fillers the nano-aluminum oxide and nanographene to the Kenaf epoxy composites. The vacuum bagging method was used to fabricate the composites. The advantage of using vacuum bagging is to reduce blowholes. The weight ratio of Kenaf fiber 50%–60%, matrix 40%, fillers nano-aluminum oxide 0%–6%, and nanographene 0%–3% was considered. Mechanical properties like Tensile strength, Young’s modulus and elongation, flexural strength, flexural modulus, hardness, impact strength, and compression strength were tested.6% nano aluminum oxide and 3% nanographene show a 125% increase in tensile strength, a 45% increase in flexural strength, and almost four times higher flexural modulus recorded. 42% increase in compression strength, and an increase of 40% in impact strength. The highest Vickers hardness is 27. An increase in primary and secondary fillers decreases and a combination of increases the mechanical properties.
An ACE2, SARS-CoV-2 spike protein binding protein, -like enzyme isolated from food-related microorganisms
Authors: Laily Izza Nur , Takeuchi Michiki , Mizutani Taku , Ogawa Jun
Published: March 2023

Angiotensin-converting enzyme 2 (ACE2) is a binding target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. An ACE2-like enzyme, such as bacterial M32-carboxypeptidase (M32-CAP), is assumed to be a potential therapeutic candidate for coronavirus disease 2019 (COVID-19). Here, we screened bacteria with an ACE2-like enzyme activity from Japanese fermented food and dietary products using the fluorogenic substrate for rapid screening. The strain showing the highest activity, Enterobacter sp. 200527-13, produced an enzyme with the same hydrolytic activity as ACE2 on Angiotensin II (Ang II). The enzymatic analysis using the heterologously-expressed enzyme in Escherichia coli revealed that the enzyme catalyzes the same reaction with that of ACE2, Ang II hydrolysis to Ang 1-7, and phenylalanine. The gene sequence information showed that the enzyme belongs to the M32-CAP family. These results suggested that the selected enzyme, M32-CAP (EntCP), from Enterobacter sp. 200527-13 was identified as an ACE2-like enzyme.