bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcriptome profiling of kisspeptin neurons from the mouse arcuate nucleus reveals new mechanisms in estrogenic control of fertility
Authors: Göcz Balázs , Rumpler Éva , Sárvári Miklós , Skrapits Katalin , Takács Szabolcs , Farkas Imre , Csillag Veronika , Trinh Sarolta H. , Bardóczi Zsuzsanna , Ruska Yvette , Solymosi Norbert , Póliska Szilárd , Szőke Zsuzsanna , Bartoloni Lucia , Zouaghi Yassine , Messina Andrea , Pitteloud Nelly , Anderson Ross C. , Millar Robert P. , Quinton Richard , Manchishi Stephen M. , Colledge William H. , Hrabovszky Erik
Published: June 2022

Kisspeptin neurons in the mediobasal hypothalamus (MBH) are critical targets of ovarian estrogen feedback regulating mammalian fertility. To reveal molecular mechanisms underlying this signaling, we thoroughly characterized the estrogen-regulated transcriptome of kisspeptin cells from ovariectomized transgenic mice substituted with 17β-estradiol or vehicle. MBH kisspeptin neurons were harvested using laser-capture microdissection, pooled, and subjected to RNA sequencing. Estrogen treatment significantly (p.adj. < 0.05) up-regulated 1,190 and down-regulated 1,139 transcripts, including transcription factors, neuropeptides, ribosomal and mitochondrial proteins, ion channels, transporters, receptors, and regulatory RNAs. Reduced expression of the excitatory serotonin receptor-4 transcript (Htr4) diminished kisspeptin neuron responsiveness to serotonergic stimulation. Many estrogen-regulated transcripts have been implicated in puberty/fertility disorders. Patients (n= 337) with congenital hypogonadotropic hypogonadism (CHH) showed enrichment of rare variants in putative CHH-candidate genes (e.g.,LRP1B,CACNA1G,FNDC3A). Comprehensive characterization of the estrogen-dependent kisspeptin neuron transcriptome sheds light on the molecular mechanisms of ovary–brain communication and informs genetic research on human fertility disorders.
Divergences of the scalar sector of quadratic gravity
Authors: Álvarez Enrique , Anero Jesús
Published: June 2022

The divergences coming from a particular sector of gravitational fluctuations around a generic background in general theories of quadratic gravity are analyzed. They can be summarized in a particular type of scalar model, whose properties are discussed. We analyze in particular with some care arguments against this particular scalar model being unitary. We also discussed the product anomaly in this context.
Non-steady state heat transport: a practical case of a microscopic energy balance in a vegetable
Authors: Tarrazó-Serrano Daniel , Castiñeira-Ibáñez Sergio , Sánchez-García Elena , Bon José , Uris Antonio , Rubio Constanza
Published: June 2022

In this paper, the analytical and numerical solutions of a non-steady state mathematical model are developed and analyzed. The mathematical model development of a non-steady state heat transport for a one-dimensional system is shown, and the analytical solution of the model is presented. The numerical solution of the model, using the finite element method (FEM), is compared to its analytical solution, proving its consistency. One of the advantages of using numerical tools is that more complex solutions can be obtained, even if the corresponding analytical solution does not exist or is not known, which is useful for engineering students. To demonstrate the applications and possibilities of this work, it is shown that changing the boundary conditions, geometry, or dimension in the system and the mathematical model, it can be solved through a numerical solution method. This is easier and more comprehensive for students rather than facing the complexity of the analytical solutions. The paper shows that it is possible to use the FEM in a university teaching context to complementarily explain the underlying physical phenomena of an engineering problem, here applied to a heat transfer problem in a vegetable.
High resolution polymer/air double-cavity Fabry–Perot fiber temperature sensor based on exposed core microstructured fiber
Authors: Tong Zhifeng , Wang Lina , Duan Tingting , Geng Youfu , Li Xuejin , Yi Duo , Hong Xueming
Published: June 2022

This study proposes a high-resolution optical fiber Fabry–Perot (FP) temperature sensor and it is based on an exposed-core microstructured optical fiber (ECF) coated by a ultraviolet curing polymer adhesive. Then, a small piece of multimode fiber (MMF) with large core diameter is spliced in front of ECF to expand the input light beam, and the parallel polymer/air double-cavity FP in such single-mode fiber (SMF)-MMF-ECF-SMF structure is constructed. Additionally, by employing a mobilized demodulation module, the interference signal is analyzed by phase demodulation method. The experimental results show that the temperature sensitivity of the sensor is 30.8 ℃−1 and the resolution is up to 1.6 × 10−4 ℃ in a range of 20 ℃–50 ℃, which can achieve high resolution temperature measurement. Furthermore, to alleviate the wavelength uncertainty of the demodulation device, a double-cavity self-reference differential phase modulation method is explored in the proposed parallel double-cavity FP. It shows that the stability could be improved to five times when system temperature is unstable, which offers an alternative method to further improve the temperature sensing resolution.
Influence of interface states on built-in electric field and diamagnetic-Landau energy shifts in asymmetric modulation-doped InGaAs/GaAs QWs
Authors: Vashisht Geetanjali , Porwal S , Haldar S , Dixit V K
Published: June 2022

The impact of interface defect states on the recombination and transport properties of charges in asymmetric modulation-doped InGaAs/GaAs quantum wells (QWs) is investigated. Three sets of high-mobility InGaAs QW structures are systematically designed and grown by the metal-organic vapor phase epitaxy technique to probe the effect of carrier localization on the electro-optical processes. In these structures, a built-in electric field drifts electrons and holes towards the opposite hetero-junctions of the QW, where their capture/recapture processes are assessed by temperature-dependent photoreflectance, photoluminescence, and photoconductivity measurements. The strength of the electric field in the structures is estimated from the Franz Keldysh oscillations observed in the photoreflectance spectra. The effects of the charge carrier localization at the interfaces lead to a reduction of the net electric field at a low temperature. Given this, the magnetic field is used to re-distribute the charge carriers and help in suppressing the effect of interface defect states, which results in a simultaneous increase in luminescence and photoconductivity signals. The in-plane confinement of charge carriers in QW by the applied magnetic field is therefore used to compensate the localization effects caused due to the built-in electric field. Subsequently, it is proposed that under the presence of large interface defect states, a magnetic field-driven diamagnetic-Landau shift can be used to estimate the fundamental parameters of charge carriers from the magneto-photoconductivity spectra instead of magneto-photoluminescence spectra. The present investigation would be beneficial for the development of high mobility optoelectronic and spin photonic devices in the field of nano-technology.
Is icosahedral short-range order presented in supercooled transition metals?
Authors: Khusnutdinoff R M , Khairullina R R , Suslov A A , Lad’yanov V I , Mokshin A V
Published: June 2022

Supercooled transition metals are characterized by the absence of long-range order and the presence of a specific short-range order in the arrangement of atoms. So, the presence of shoulders and broadenings at the second maximum in the experimentally measured quantity—in the static structure factor S(k)—is usually interpreted as a manifestation of the icosahedral (ideal or distorted) short-range order (ISRO—Icosahedral Short-Range Order). Icosahedral short-range order is a structure with fivefold symmetry in the arrangement of atoms, which can lead to the possibility of achieving deep supercooling. In this work, we study the local structural features of equilibrium and supercooled nickel melts under various cooling protocols (

γ
∈

10

10

,

10

14

 K s−1) in order to clarify the mechanism of formation of the icosahedral short-range order in pure transition metals. Comprehensive studies of the properties of nickel melts were carried out using experiments on x-ray diffraction, large-scale molecular dynamics (MD) simulations with subsequent structural and cluster analysis. A good agreement was found between the results of x-ray diffraction data and the MD simulations results for an equilibrium nickel melt. It was found that the nickel melt is characterized by a short-range order, formed by fragments of icosahedra and distorted icosahedral clusters. It was revealed that the ‘liquid-crystal’ phase transition in nickel is accompanied by the transformation of distorted icosahedral clusters into clusters with the fcc/hcp-symmetry. It is shown that, in contrast to the Voronoi tessellation method, the cluster analysis method based on the (

q
4

,

q
6

) rotational invariants does not allow sufficiently correct identification of the distorted icosahedral short-range order in metal melts.
Direct-write formation of integrated bottom contacts to laser-induced graphene-like carbon
Authors: Murray Richard , O’Neill Orla , Vaughan Eoghan , Iacopino Daniela , Blake Alan , Lyons Colin , O’Connell Dan , O’Brien Joe , Quinn Aidan J
Published: June 2022

We report a simple, scalable two-step method for direct-write laser fabrication of 3D, porous graphene-like carbon electrodes from polyimide films with integrated contact plugs to underlying metal layers (Au or Ni). Irradiation at high average CO2 laser power (30 W) and low scan speed (∼18 mm s)−1 leads to formation of ‘keyhole’ contact plugs through local ablation of polyimide (initial thickness 17 μm) and graphitization of the plug perimeter wall. Top-surface laser-induced graphene (LIG) electrodes are then formed and connected to the plug by raster patterning at lower laser power (3.7 W) and higher scan speed (200 mm s)−1. Sheet resistance data (71 ± 15 Ω sq.)−1 indicates formation of high-quality surface LIG, consistent with Raman data which yield sharp first- and second-order peaks. We have also demonstrated that high-quality LIG requires a minimum initial polyimide thickness. Capacitance data measured between surface LIG electrodes and the buried metal film indicate a polyimide layer of thickness ∼7 μm remaining following laser processing. By contrast, laser graphitization of polyimide of initial thickness ∼8 μm yielded devices with large sheet resistance (>1 kΩ sq.)−1. Raman data also indicated significant disorder. Plug contact resistance values were calculated from analysis of transfer line measurement data for single- and multi-plug test structures. Contacts to buried nickel layers yielded lower plug resistances (1-plug: 158 ± 7 Ω , 4-plug: 31 ± 14 Ω) compared to contacts to buried gold (1-plug: 346 ± 37 Ω , 4-plug: 52 ± 3 Ω). Further reductions are expected for multi-plug structures with increased areal density. Proof-of-concept mm-scale LIG electrochemical devices with local contact plugs yielded rapid electron transfer kinetics (rate constant k
0 ∼ 0.017 cm s−1), comparable to values measured for exposed Au films (k
0 ∼0.023 cm s)−1. Our results highlight the potential for integration of LIG-based sensor electrodes with semiconductor or roll-to-roll manufacturing.
Maximal mixed parabolic–hyperbolic regularity for the full equations of multicomponent fluid dynamics
Authors: Druet Pierre-Etienne
Published: June 2022

We consider a Navier–Stokes–Fick–Onsager–Fourier system of PDEs describing mass, energy and momentum balance in a Newtonian fluid with composite molecular structure. For the resulting parabolic–hyperbolic system, we introduce the notion of optimal regularity of mixed type, and we prove the short-time existence of strong solutions for a typical initial boundary-value-problem. By means of a partial maximum principle, we moreover show that such a solution cannot degenerate in finite time due to blow-up or vanishing of the temperature or the partial mass densities. This second result is however only valid under certain growth conditions on the phenomenological coefficients. In order to obtain some illustration of the theory, we set up a special constitutive model for volume-additive mixtures.
Global boundedness of solutions to a parabolic–parabolic chemotaxis system with local sensing in higher dimensions
Authors: Fujie Kentaro , Senba Takasi
Published: June 2022

This paper deals with classical solutions to the parabolic–parabolic system

u

t

=
Δ

(

γ

(

v

)

u

)

i
n

Ω
×

(

0
,
∞

)

,

v

t

=
Δ
v
−
v
+
u

i
n

Ω
×

(

0
,
∞

)

,

∂
u

∂
ν

=

∂
v

∂
ν

=
0

o
n

∂
Ω
×

(

0
,
∞

)

,

u

(

⋅
,
0

)

=

u

0

,

v

(

⋅
,
0

)

=

v

0

i
n

Ω
,

where Ω is a smooth bounded domain in R

n
(n ⩾ 3), γ(v) = v
−k
(k > 0) and the initial data (u
0, v
0) is positive and regular. This system has striking features similar to those of the logarithmic Keller–Segel system. It is established that classical solutions of the system exist globally in time and remain uniformly bounded in time if k ∈ (0, n/(n − 2)), independently of the magnitude of mass. This constant n/(n − 2) is conjectured as the optimal range guaranteeing global existence and boundedness in the corresponding logarithmic Keller–Segel system. In the course of our analysis we introduce an auxiliary function and derive an evolution equation that it satisfies. Using refined comparison estimates we control the behavior of the nonlinear term in the equation for the auxiliary function, and this in turn yields sufficient information to control solutions of the original system.
Uniqueness in a Navier–Stokes-nonlinear-Schrödinger model of superfluidity*
Authors: Jayanti Pranava Chaitanya , Trivisa Konstantina
Published: June 2022

In Jayanti and Trivisa (2022 J. Math. Fluid Mech.
24 46), the authors proved the existence of local-in-time weak solutions to a model of superfluidity. The system of governing equations was derived in Pitaevskii (1959 Sov. Phys. JETP
8 282–287) and couples the nonlinear Schrödinger equation and the Navier–Stokes equations. In this article, we prove a weak–strong type uniqueness theorem for these weak solutions. Only some of their regularity properties are used, allowing room for improved existence theorems in the future, with compatible uniqueness results.
Performance enhancement of perovskite solar cells based on a CdO-quantum dot/TiO2-nanocrystal array electron transport layer
Authors: Su Chaoying , Wang Yuwen , Wu Jing , Xu Huanyan , Zhou Hong , Jin Liguo
Published: June 2022

An oriented TiO2 nanocrystal array (TiO2-NA) shows a unique electron extraction capability for perovskite solar cells (PSCs) due to it having fewer grain boundaries and high crystallinity for effective charge collection. Based on these advantages, we prepared PSCs based on TiO2-NA mesoporous film (mp-film), and chose CdO quantum dots (QDs) as the modifier of the TiO2-NA mp-film. The diameter of a single TiO2-NA and the TiO2-NA gap were controlled by controlling the hydrothermal reaction time. The CdO-QDs/TiO2-NA mp-film, as the electron transporting layer (ETL), was prepared by successive ionic layer adsorption and the reaction-sintering method. In this work, oxidation state CdO QDs were first used as the modifier in the ETL of the PSC. We gradually optimized the CdO/TiO2-NA mp-film by controlling the hydrothermal reaction time of TiO2-NA to improve PSC performance. Infiltration of the perovskite absorber–submicrometer-thick rutile TiO2-NA mp-films with Spiro-MeOTAD yielded a strikingly high photoelectric conversion efficiency of 11.94% under AM 1.5G illumination. The dependence of photovoltaic performance and interfacial electronic behavior on the length of the CdO/TiO2-NA was also investigated.
High power density soft x-ray GaAs photodiodes with tailored spectral response
Authors: Donetski Dmitri , Kucharczyk Kevin , Liu Jinghe , Lutchman Ricardo , Hulbert Steven , Mazzoli Claudio , Nelson Christie , Podobedov Boris
Published: June 2022

GaAs photodiode arrays have been designed for non-destructive monitoring of x-ray beam position in soft coherent beamline front ends in synchrotron light sources. A shallow p-on-n junction was employed to reduce the device photocurrent density to optimize the operation with beam power densities up to 20 W mm−2, mainly coming from hard x-rays. With this approach, the photocurrent is primarily defined by the excess carriers generated by low-energy x-ray photons absorbed near the detector surface. The p–n junction structures were grown by molecular beam epitaxy and processed into 64-element linear photodiode arrays. The devices were characterized first in the visible range with a high-power Ar-ion laser and then tested in the soft and hard x-ray regions up to 10 keV at two beamlines of the National Synchrotron Light Source II. The responsivity was measured to be 0.16 A W−1 at 0.7 keV and 0.05 A W−1 at 6 keV in agreement with modeling. At higher x-ray energies the measured responsivity was lower than predicted in the framework of the carrier diffusion model; a possible explanation is discussed.
Probability seismic demand and fragility analyses of novel SMA-based self-centring eccentrically braced frames
Authors: Chen Zhi-Peng , Zhu Songye
Published: June 2022

This paper performs the seismic assessment of novel shape memory alloy (SMA)-based self-centring (SC) eccentrically braced frames (EBFs) by using probabilistic seismic demand analysis (PSDA) and probabilistic seismic fragility analysis (PSFA). The structural finite element models are established based on a previous prototype building and verified through test results. The PSDA is based on a set of 176 seismic records, andSaavgis chosen as the proper intensity measure for max inter-storey drift ratio (MIDR) and max inter-storey residual drift ratio (MIRR); whereas peak ground acceleration is more suitable for peak floor acceleration (PFA). After the PSDA results are obtained, time-history analyses and PSFA are conducted. Compared with traditional steel EBFs, the SMA-based SC-EBF shows a slight weakness in MIDR due to the comparatively small energy dissipation capacity but has an apparent advantage in controlling MIRR due to a good SC capacity provided by SMA angles. Furthermore, although the steel EBF with fixed column bases has the smallest MIDR, the fixed bases cause extra damage in column bases, which will bring other problems in post-earthquake rebuild and deviate from the design target of concentrating damage in link beams. The variability of the PFA is small, showing that the influence of structural forms on PFA is not apparent. Considering the overall structural seismic performances in terms of MIDR, MIRR and PFA, SMA-based SC-EBF can be a promising alternative in future seismic-resistant designs.
Separation behaviour of polypropylene mixed particles under the coupling of vibration and airflow
Authors: Zhao Lei , Ma Xuedong , Li Lingling
Published: June 2022

Granular matter is a disordered system composed of a large number of particles, which appears as a complex physical phenomenon under external excitation. To study the separation behaviour of polypropylene particles, the separation of particles under various excitation methods was simulated based on the DEM-CFD coupling method. The results showed that polypropylene particles did not show Reverse Brazil Nut Separation under the single excitation of either vertical vibration or pulsed airflow, while under the double excitation of vertical vibration and constant airflow, the large particles located in the upper layer of small particles started to sink and formed Reverse Brazil Nut Separation. By analysing the change of voidage in particle bed, the explanation of the change of particle separation state by filling theory is verified. The airflow velocity increased from 15 m·s−1 to 21 m·s−1, and the volume concentration of large particles at the bottom increased by 27.615%, which promoted the formation of Reverse Brazil Nut Separation. The frequency and amplitude increased to 15 Hz, 20 mm or decreased to 5 Hz, 5 mm, respectively, and the volume concentration of large particles at the bottom decreased by 22.025%, 23.807% and 46.712%, 59.003%, indicating that too large or too small vibration acceleration would inhibit the formation of Reverse Brazil Nut Separation. In addition, changing the shape of the container or increasing the filling rate of particles in the container can eliminate the phenomenon of small particles accumulating in the corner.
Near field propagation of hollow higher-order cosh-Gaussian beam in jet engine induced turbulence
Authors: Bayraktar Mert
Published: June 2022

Propagation of hollow higher-order cosh-Gaussian (HHOCG) beam through jet engine induced turbulence is analyzed in this article. Special form of Huygens–Fresnel integral is solved in order to find averaged received intensity. Since beam shows rapidly focusing behavior, intensity profile is analyzed for short propagation distances. Beam evolves into four petal shape at short distance and size of hollow in the center is directly proportional with beam parameters. Raise in these parameters brings longer focusing point along propagation axis. Surprisingly, beam shows focusing behavior along propagation. According to our results, we think that especially this focusing trend is useful for applications required line of sight alignment like directed infrared counter measure (DIRCM).
Inertial force in separators used for oil treatment units
Authors: Yagafarova Kh N , Zaydullina A N
Published: June 2022

The paper studies the force of inertia to appear both in individual parts and assemblies of separators exploited for oil and gas treatment, and in separators as such. The concept of the force of inertia is important due to the possibility of considering it from deeper scientific points of view and practical positions.
Wave-pulse simulation in high-viscosity oil wells
Authors: Shipulin A V , Mingulov I Sh , Mukhametshin V V , Mingulov Sh G , Kuleshova L S
Published: June 2022

The thixotropic properties of high-viscosity oils have been found to be highly dependent on temperature and pressure treatment. As the temperature increases, the efficiency of the wave-pulse method to reduce the thixotropic properties of high-viscosity oil increases. The effect of the wave interference on the productive formation decreases over time, and after 3-7 days of development, the well must be treated again to ensure its operation in an intensive mode. Wave-pulse treatment facilitates the separation of light fractions from high-viscosity oil and hydrophobization of the reservoir. Heat and wave-pulse treatments complement each other and contribute to a complex effect on high-viscosity oil, but they must be carried out simultaneously or alternated with minimal interruptions in order to avoid the space lattice restoration.
Improvement of disc stack centrifuge design to increase efficiency of formation fluid separation
Authors: M Ya Khabibullin
Published: June 2022

It should be noted that numerous theoretical studies on flow hydromechanics in the centrifugal field have not been sufficiently used in designing separators with a high productivity index. This is caused by the extreme complexity of the flow conditions of the separated liquid in the intrarotor space. Therefore, experimental studies of intra-rotor flows have now gained great importance. The obtained results of studies carried out on a real product at a pressure and flow rate corresponding to production conditions made it possible to create and manufacture an industrial sample of the assembly. The authors use experimental data to calculate similar hydrocyclones ment for operation with other mixtures.
Principles of developing insulators for acoustic logging tools
Authors: A M Gilmanova
Published: June 2022

The paper describes the requirements for acoustic insulators, experimental and theoretical foundation of insulator structure, and proves the appropriate calculations. The work output is the modernized design of insulators that suppress interference waves between the transmitter and receiver of the downhole probe depending on the equipment used and the well under study.
Introduction of modern information and communication technologies in transport flow management
Authors: Abdullaev Z , Ziyodullaeva G E , Muhamedieva D T
Published: June 2022

The article proposes an economic mechanism for regulating the route network, the calculation of which allows you to choose a transport route, as well as calculate the number of flights based on the condition of achieving a break-even transport process for carriers of various forms of ownership. The Work deals with the solution of problems related to the choice of a route, which belong to the class of complex combinatorial optimization problems. They don't have simple analytical solutions. As the number of nodes increases, the computational complexity increases exponentially. The Work proposes an alternative method for solving routing problems based on the use of neural network models, which allow obtaining good suboptimal solutions with a significant reduction in time costs. As in the Hopfield network, a matrix of neurons is used here, but neurons interact not on the "each with each" principle, but in rows and columns.
Network architectures and protocols of M2M communications
Authors: Khasambiev I V , Guseva E A
Published: June 2022

The issues of building the architecture of M2M networks and managing M2M services using the capabilities of the IMS platform are considered Introduction. M2M (Machine to Machine) is a complex of technologies that provide automatic interaction between devices (things) without human intervention. The Internet of Things is not a single technology, but a whole system of technological solutions. It is a global network infrastructure, which consists of computer networks of physical objects, the traditional IP Internet, and various devices connecting these networks.
Developing method for constructing modular turbo code for anti-jam satellite authentication system
Authors: Kalmykov I A , Mukhametshin V Sh , Tyncherov K T , Selivanova M V
Published: June 2022

Low-earth orbit (LEO) satellite communication systems must have anti-jam property, which is based on information, structural and energy secrecy as well as immunity to jamming. One of the directions associated with increasing information secrecy is based on the use of a satellite identification system. This system is designed to prevent the imposition of foreign content on the subscriber through the use of an authentication protocol built on proof with zero knowledge. To reduce the time of applicant identification, a number of works propose to use modular codes (MC), which allow parallelizing the computational process in the protocol. It is known that MCs can improve the fault tolerance of the identification system since they are able to eliminate the consequences of faults and failures during operation. However, they can also be used to improve the immunity of LEO satellite communication systems to jamming. Thus, the use of a unified algebraic system when constructing MCs capable of correcting errors caused not only by faults and failures during the operation of the identification system but also by interference in the communication channel will enable to abandon concatenated codes. Therefore, the development of a method for constructing a modular turbo code for an anti-jam satellite authentication system is an urgent task.
Diagnostics of a shipboard cable by measuring the dielectric loss tangent
Authors: Vlasov A , Buev S
Published: June 2022

Until now there has not been created a system to assess the residual resource and to predict the probability of shipboard cable failure during its operation by non-destructive methods. Periodic high voltage tests are prescribed by various guidelines. As a result of such diagnostics, the damaged section is identified and the entire cable route is replaced. Obviously, this technology does not prevent an emergency situation, does not provide information about the residual resource, and finally, worsens the properties of an already aged cable exposed to high voltage. Insulation quality control on ships is of great importance and significance. The question arises about the suitability of one or another cable route for further work after long-term operation. That is why the issues of predicting the service life of a cable and assessing its current technical condition are relevant. Modern technologies make it possible to obtain materials with improved characteristics; however, currently rubber-insulated cables are the most common. In this work, diagnostics of the state of a shipboard cable is carried out by determining the dielectric loss tangent of its insulation. This method can be used along with traditional methods for technical audit of shipboard cables, such as testing the hardness of the cable sheath, infrared diagnostics of electrical equipment. In this case, the conclusion about the current state of the cable and the forecast of its service life, in the opinion of the authors, can only be made on the basis of the results of comprehensive diagnostics performed by several methods.
Improvement of the power grid system of the East Siberian Railway
Authors: Suslov K V , Logacheva A G , Zatsarinnaya Yu N , Gladkikh V A , Karlina A I , Baraboshkin K A
Published: June 2022

The foreign experience analysis and the mathematical modeling system use have shown that the use of virtual coupling train driving technology will increase line section by an average of 10 to 40%, depending on the energy network and traffic schedule saturation. For a batch schedule consisting, we reduce the interval to the minimum value. According to the calculation results of the power network system operating modes, it is clear that all the traction network characteristics accept the permissible norms.
Justification of measures aimed at increasing the capacity of a section of a railway line, taking into account its required electrical capacities
Authors: Karlina A I , Akhmetshin A R , Suslov K V , Olentsevich V A , Sivtsov A V , Karlina Yu I
Published: June 2022

The annual increase in cargo turnover to the Far Eastern seaports contributes to the optimization of the railway infrastructure in order to increase the level of throughput and processing capacity of the Baikal-Amur Mainline and Trans-Siberian Railway facilities. JSC Russian Railways pays special attention to these issues. Organization and promotion of car traffic through the formation of freight trains using the connection technology, “virtual coupling”, heavy and dual trains that move on an ongoing basis is one of the innovative methods for increasing the carrying capacity for highly loaded sections and directions at a level of utilization of their throughput of 0, 8 or more. Under these conditions, the organization of efficient power supply of railway sections and facilities is the main factor influencing the value of the throughput capacity of transport infrastructure facilities. The article presents a technical justification for the measure aimed at increasing the throughput and processing capacity of a section of a railway line, taking into account the stability check of the devices of the traction power supply system. The predicted parameters of the operation of the traction power supply system of the railway line section are given with a promising train schedule.
Forecasting the parameters of structures from natural materials taking into account environmental impact
Authors: Lvovich I Ya , Lvovich Ya E , Preobrazhensky A P , Preobrazhensky Yu P , Choporov O N , Melnikova T V
Published: June 2022

The paper deals with the problems of building structures with certain values of stability parameters based on the corresponding values of material parameters. For modeling, a passive experiment is used based on archival information for building structures. An algorithm using forecast models is built. Its main stages are given, they are indicated in the diagram. The algorithm is based on statistical approaches. The constructed forecast models for stone natural building materials, for binding materials, for forest materials are presented. During the construction of the regression model the authors proceeded from the independence of the experiments, as well as the fact that the nature of various random components remained unchanged in all experiments. The built models may be used to forecast changes in design parameters when the selected characteristics change.
Vibrations of high-rise buildings under seismic impact taking into account physical nonlinearity
Authors: Mirzaev S , Yusupov M , Rakhmankulova B , Abdikayimova G
Published: June 2022

Analytical description of vibration loads of the complex construction structure is considered as a system of masses connected by means of viscoelastic springs. To take into account the rheological properties of the spring material, the Boltzmann-Volterra principle is used. A mathematical model of the problem under consideration has been developed, which boils down to the solution of a system of nonlinear integro-differential equations. A solution method based on the use of quadrature formulas has been developed and a computer program has been compiled on its basis. The results are shown as graphs. Influence of nonlinear and rheological properties of spring on amplitude and phase of mass oscillations is investigated.
Surface properties of binary and ternary solutions studied through precision measurements
Authors: Dzhambulatov R S , Talkhigova Kh S , Umarova L Kh
Published: June 2022

The paper deals with the surface properties of aqueous two- and three-component organic solutions (water-acetone; water-1,4-Dioxane; water-acetone-1,4-Dioxane). A modern installation, K-100 tensiometer, was used to measure equilibrium surface or interfacial tension, contact angle, etc. The du Noüy ring and the Wilhelmy plate methods were used to measure the surface tension. It shows that the surface tension isotherms for a ternary system do not contain any features uncharacteristic of the surface tension isotherms for lateral binaries. The findings made it easy to specify the adsorption of surface-active agents in water. It shows that the nature of the ternary adsorption isotherms qualitatively coincides with the binary adsorption isotherms, which leads to the conclusion that, once used together as surfactants, organic substances (acetone and 1,4-Dioxane) in water does not enhance the surface activity of each other.
Development of algorithms for control and control of electric power parameters based on information-measuring system data
Authors: Sokolov A A , Fomenko O A , Ignatev I V
Published: June 2022

The article describes the operation of the information-measuring system and the algorithms for the control and management of electric power parameters developed by the authors. This is an algorithm for controlling energy parameters for the stable operation of an industrial facility. The basic principles of monitoring, control and regulation of energy parameters of an industrial facility for the uninterrupted operation of technological processes are described. Recommendations are given for the creation of special software and algorithmic support and its implementation at the enterprises of the Russian Federation.
Physical and software bases of the device operation for remote measurement of human body temperature
Authors: Kuznezova A V , Rybakov A V , Melnikova A I , Khasanshin I Ya , Semenov D N , Kruglov V I
Published: June 2022

A method of automated control of human temperature in public places is proposed, which allows determining people with elevated temperature immediately at the control point. To develop the technique, an experimental stand was designed and implemented in a rack with six built-in infrared sensors. To recognize a person with an elevated temperature, an artificial neural network was used in the form of a multilayer perceptron, at the input of which there were IR sensor data. The conducted experiments showed that the trained model based on the F1-metric efficiency of 0.89 to 0.94 determines a person with an elevated temperature.
Modeling of loading and unloading processes
Authors: Khaydarov T A , Utepov B B , Rajabov N Q , Kulmamatov O A , Кholiyarov M Sh , Akhmetova S T
Published: June 2022

The article theoretically examines the choice of the most optimal of the possible trajectories of cargo in the process of moving goods from one place to another, placing them in the most optimal shape and size, taking into account the characteristics of the cargo. At the same time, using the method of mathematical modeling, the position of objects in space was determined using the functions of the Cartesian and polar coordinate systems. For optimal planning and management of the placement of goods, as well as transport operations along any spatial trajectory, the matrix method of mathematical modeling of these processes was used. Practically all possible cases of cargo movement were investigated and a mathematical expression was formed taking into account the geometry and kinematics of their placement in the given volumes. Based on the results of theoretical studies, three conclusions were drawn
Mathematical modeling of power consumption based on rank analysis
Authors: Klyuev R V , Guzueva E R , Bulatov Yu N
Published: June 2022

In the article, based on the application of the rank analysis of the technocenosis, mathematical modeling of electricity consumption by consumers for the production of hard alloys is carried out. Two methodological levels of research in the field of energy-saving and power consumption are presented. At the same time, it was found that rank analysis allows you to streamline information, effectively predict power consumption by individual objects to identify dynamics, and visually represent objects with abnormal power consumption. The analysis of the results obtained confirms the efficiency of using the H-distribution for obtaining mathematical models of power consumption of Noah and Pointer castes in the production of hard alloys. For the first time, the regularity of changes in electricity consumption by technological equipment was established, which is described by an adequate mathematical model in the form of a damped harmonic function. The resulting model is recommended for use in an automated dispatching control system for electricity consumption for the purpose of short-term forecasting of electricity consumption.
Optimal routes choice for maintenance units moving to service electrical equipment of agricultural facilities
Authors: Zhdanov V G , Logacheva E A , Yarosh V A , Ivashina A V
Published: June 2022

In the conditions of agricultural production, electrical equipment is affected by a large number of unfavorable factors; therefore, the role of its technical operation increases sharply. Maintaining the operational reliability of electrical equipment at the required level is ensured by the timely implementation of their scheduled maintenance and repairs. The implementation of these measures in the conditions of agricultural enterprises is associated with certain difficulties, since electrical equipment is located in a number of areas in agriculture, remote from one another at a considerable distance. Statistical data show that a significant amount of working time is spent on transitions and transfers, which sharply reduce the labor productivity of workers in maintenance units. The article deals with problems of using mathematical programming methods for choosing the optimal routes to transport maintenance units to service electrical equipment. The method for finding the shortest route for moving maintenance units to service electrical equipment of agricultural facilities has been developed.
Prospects for creating a «smart» village
Authors: Konyukhov V Yu , Permyakova D N , Olentsevich V A
Published: June 2022

This article provides an analysis of the prospects for creating "smart" villages that meet international standards of quality of life. The relevance assessment is carried out within the framework of the Digital Economy of the Russian Federation project in order to modernize agriculture, as well as to increase productivity taking into account population density in various regions of the country. Examples of successfully implemented projects of "smart" villages outside the Russian Federation are presented as a basis for analysis. In conclusion, the conclusion is made about the possibility of forming "smart" villages in the Russian Federation.
Hydrodynamic Performances of Aeronautical Propeller for Drones
Authors: Martellini Edoardo , Aloisio Giovanni , Grizzi Silvano , Falchi Massimo , Pagliaroli Tiziano
Published: June 2022

Currently, several countries already invest on the application of drones for different scopes. These purposes are mainly civilian and military and some of these include the presence of water as search and rescue, inspection of pipelines, getting a bird’s eyes view over oil spills or structural integrity monitoring of bridges. For this reason, an interesting feature for drones is their ability to maneuver in fluids with different density as air and water. This research topic, shows strong scientific potentiality but it also represents a great challenge from scientific and technical view point: i) aeronautical propeller for drones in water must generate reverse thrust or braking force through an off-design rotation in off-design condition (different fluid’s density); ii) the propeller rotational velocity in water is generally one order of magnitude lower than the one for air application requiring the motors to be properly desing to meet such a wide operational range. In this paper, an experimental campaign aimed at the performance quantification of a three-bladed propeller for drone propulsion in water has been carried out in a towing tank. In particular, the generated forces are acquired through a load cell for different advance ratios J provided by varying both rotational regime and free stream velocity. The results show expected losses in the performance for the off-design rotation in terms of both thrust and efficiency. At low rotational speeds, higher values of efficiency are presented for small advance ratio. The maximum efficiency increase for higher RPS and it’s slightly influenced by small variation of propeller disk angle.
Non-contact techniques based on a vision system for the inspection of composite material components: analysis of the influence quantities
Authors: Chiominto Luciano , D’Emilia Giulio , Natale Emanuela
Published: June 2022

In this paper two different approaches, based on a vision system, are compared for the inspection of a carbon fibre piece, realized using a tow filament winding process. The defect of interest is the surface void percentage, which can strongly influence the mechanical and functional characteristics of the component. The approaches differ in the method of image processing: the first is based on a colour threshold setting; the second is based on a semantic segmentation algorithm. The comparison between the two techniques allows the identification of the main causes of variability, and the individuation of the advantages and limits of each one, which make them more or less suitable for use, depending on the specific application. The preliminary results show that both methods are promising for in field use, provided that the causes of variability are identified and kept under control.
Infrared Thermography Measurements over a Tail-Plane Model of a Large Passenger Aircraft
Authors: Zanotti A. , Rausa A. , Grassi D. , Riccobene L. , Braukmann J.N. , Schwarz C. , Gibertini G. , Guardone A. , Auteri F.
Published: June 2022

In the frame of the CleanSky 2 MONNALISA project, a wind-tunnel campaign is planned to test a tail-plane model of a large passenger aircraft by using different measurement techniques. Wind-tunnel test results obtained over a systematic series of model geometries will be used to thoroughly validate a low-order numerical method based on physical modelling that will be developed in the project to evaluate the non-linear aerodynamic characteristics of aircraft lifting surfaces. The present paper describes the main results of the infrared thermography measurements performed in the first wind-tunnel entry to be used to tune RANS solvers and for the fine calibration of the low-order numerical method.
Directional transport of droplets impacting on superhydrophobic opening triangular groove surfaces
Authors: Li Yunlai , Lu Chenguang , Liu Yahua
Published: June 2022

Directional droplet transport is of great importance to various processes including heat transfer, water harvesting and microfluidics. Here, a facile superhydrophobic opening triangular groove surface was proposed, and the directional transport behavior of droplets impacting on the surface was observed. The results show that the essence of the directional transport on the opening triangular groove surface can be attributed to the interaction between the impinging droplet and the groove sidewall, and the directional transport distance is regulated by the contact area during the interaction. Further, by controlling the depth of triangular groove, the triangular opening angle, the impacting point position and the Weber number, the contact area between the droplet and the groove sidewall during the interaction can be changed, leading to the variation of directional transport distance. This study provides a new method for directional droplet transport on superhydrophobic surfaces and offers more options for the manipulation of droplet behavior.
Nano-Si/graphite/N-doped biocarbon hybrid anode material for high-performance lithium-ion batteries
Authors: Wang Yuanshen , Wu Borong
Published: June 2022

Improving the cycle life of silicon-based anodes is extremely important to the development of Li-ion batteries. Nano-silicon / graphite / Nitrogen-doped carbon composites are prepared as hybrid anode material in this work. The nano-silicon particles are distributed in the graphite framework, which improves the electrical conductivity of the composite. The amorphous nitrogen-doped carbon layer of the composite could be a buffer structure for the volume change of Si while providing a fast transport channel for lithium ions and further enhancing the electrical conductivity of the composites. The specific capacity of the composite electrode is 656.5 mAh g-1 at 500 mA g-1. The capacity retention rate is 91% after 100 cycles. The composite electrode could deliver a specific capacity of 497.3 mAh g-1 after 200 cycles even at a large current density of 1A g-1.
Oxidation kinetics of a low-grade vanadiferous titanomagnetite concentrate with high titanium
Authors: Liu Jinsheng , Cheng Gongjin , Liu Jianxing , Yue Hongrui , Ding Xueyong , Xue Xiangxin
Published: June 2022

In order to better develop and utilize the low-grade vanadiferous titanomagnetite concentrate with high titanium (LVCHT) and provide reference for the treatment of similar minerals. Oxidation process and kinetics of the LVCHT were investigated in this study. The results show that LVCHT presents weight loss at temperatures less than 600 °C, which is attributed to the removal of moisture and volatile components. Above 600 °C, the weight gain of LVCHT is due to the persistence of oxidative behavior, and the oxidation process is most likely controlled by external diffusion, and the associated activation energies (Ea) and the value of k

0
are 29.89 kJ/mol and 0.64, respectively.