bluuebunny/crossref_metadata_2025 huggingface dataset:
Blockage influence on bi-stable flows of a notchback bluff body
Authors: He Kan , Minelli Guglielmo , Su Xinchao , Gao Guangjun , Krajnović Siniša
Published: December 2021

The expected flow asymmetry behind a three-dimensional notchback Ahmed body is numerically investigated using large-eddy simulations with different blockage ratios of 0%, 5%, 10%, and 20%. The focus of the study is on the natural bi-stable flow influenced by the blockage ratio. Although the wake asymmetry can be observed under the blockage ratio within 0%−10%, the significant blockage influence on the sensitive bi-stability is indicated by the wake structures, pressure gradients, and wake dynamics achieved with the proper orthogonal decomposition. The higher blockage ratio increases the turbulence kinetic energy, velocity, and negative pressure in the near-wake region, resulting in the decrease in the asymmetry degree. The consistency of the asymmetric wake is found with blockage ratios between 0% and 5%. However, a 20% blockage ratio symmetrizes the bi-stable wake. Several existing drag corrections for the blockage influence are discussed. The wind tunnel experiment verifies the bi-stable flow with low blockage ratios and the wake symmetrization with a 20% blockage ratio.
The involvement of hypoxia-inducible factor 1α (HIF1α)-stabilising factors in steroidogenic acute regulatory (STAR) protein-dependent steroidogenesis in murine KK1 granulosa cells
Authors: Gysin Tina , Kowalewski Mariusz P.
Published: December 2021

As a component of hypoxia-inducible factor 1 (HIF1)-complexes, HIF1α regulates the expression of steroidogenic acute regulatory (STAR) protein in granulosa cells. However, severe hypoxia or exaggeratedly expressed HIF1α have detrimental effects. HIF1α is regulated by factor inhibiting HIF (FIH), prolyl hydroxylases (PHD1, 2, 3) and von Hippel-Lindau (VHL) suppressor protein. In this study, the expression of FIH, PHD1, 2, 3 and VHL was investigated in murine ovaries and immortalised KK1 granulosa cells. We found FIH, VHL and PHD2 transcripts predominantly in growing tertiary follicles. Functional aspects were assessed in KK1 cells exposed to decreasing O2 (20%, 10%, 1%), by determining HIF1α, FIH, VHL, PHD1–3 and STAR expression. The main findings indicated gradually increasing PHD2 under lowered O2. Functional blocking of PHDs revealed biphasic effects on STAR expression; concomitantly with increasing HIF1α, STAR expression, which was initially induced, decreased significantly when HIF1α was strongly stabilised. Finally, PHD2 in particular might act as a specific regulator of HIF1α and, thereby, of STAR availability in granulosa cells.
A polygenic score for educational attainment partially predicts voter turnout
Authors: Dawes Christopher T. , Okbay Aysu , Oskarsson Sven , Rustichini Aldo
Published: December 2021

Significance

The strong correlation between education and voting is among the most robust findings in social science. We show that genes associated with the propensity to acquire education are also associated with higher voter turnout. A within-family analysis suggests education-linked genes exert direct effects on voter turnout but also reveals evidence of genetic nurture in second-order elections. Our findings have important implications for the study of political inequality. Scholars have argued that parental education is the main driver of the reproduction of political inequality across generations. By separating the effect of genes from parental nurturing, our findings suggest that the roots of individual-level political inequality run deeper than family background.
Decoding the link of microbiome niches with homologous sequences enables accurately targeted protein structure prediction
Authors: Yang Pengshuo , Zheng Wei , Ning Kang , Zhang Yang
Published: December 2021

Significance

Metagenome sequencing provides a useful repository to extract evolutionary information and assist protein structure predictions. The sequence-search process, however, becomes increasingly prohibitive due to the huge library size. We hypothesize that there exist inherent evolutionary linkages between microbial niches and protein families that can be used to construct precise multiple sequence alignments (MSAs). To examine the hypothesis, we built a model library of four major biomes containing 4.25 billion sequences. Large-scale protein folding experiments revealed that MSAs collected from individually linked microbiomes can generate more accurate contact and structure models than those from all microbiome sequences but use significantly fewer computing resources. These results demonstrate the potential to solve the metagenome-search problem using a microbiome targeted approach.
Sediment load determines the shape of rivers
Authors: Popović Predrag , Devauchelle Olivier , Abramian Anaïs , Lajeunesse Eric
Published: December 2021

Significance

Rivers carry and deposit sediment, thereby shaping most landscapes around us. In doing so, their malleable channels change shape to accommodate the sediment load. Here, we show how fluid stress, gravity, and the erratic trajectories of traveling grains combine together to determine the shape of a river. We find that the stress on the bed of a river cannot be significantly above the critical value for sediment motion, which bounds the intensity of sediment transport and, thus, forces the river to widen as its sediment load increases. Although our results relate directly only to experimental, laminar rivers, they likely also apply qualitatively to natural ones, potentially allowing us to use the shape of a river as a proxy for its sediment discharge.
Age of exposure and subject/object asymmetries when wh-movement goes rightward
Authors: Cecchetto Carlo , Checchetto Alessandra , Giustolisi Beatrice , Santoro Mirko
Published: December 2021

We report an experiment addressing the comprehension of LIS interrogatives in three adult populations with different times of exposure to sign language: native signers, early signers, and late signers. We investigate whether delayed exposure to language affects comprehension of interrogatives and whether there is an advantage for subject dependencies over object dependencies, as systematically reported for spoken languages. The answer to the first question is positive: there is evidence that natives outperform non-native signers, confirming permanent effects of delayed exposure to sign language even decades after childhood. However, the performance in subject interrogatives was lower than in object interrogatives in all groups of participants. We discuss several possible reasons for this unexpected finding.
A study of the ability to judge surface emotion and real emotion in children between four to six years of age (Estudio sobre la capacidad de identificar y diferenciar entre emociones visibles y emociones reales de los niños de cuatro a seis años)
Authors: Zhao Jiaxu , Xiang Yanhui , Dai Mingyu
Published: December 2021

This study investigated differences between the ability to judge surface emotions and real emotions in pretend/deceptive situations. Using the scenario approach, our results showed that the ability to judge surface/real emotions is affected by pretend and deceptive situations in children aged 4–6 years. We found that in pretend situations, the accuracy of judging surface emotion was higher than that for real emotions in children aged four and five years. In four-year-old children, the accuracy of judging surface emotion in pretend situations was higher than that in deceptive situations; however, in children aged four and five years, the accuracy of judging real emotions in deceptive situations was higher than that in pretend situations. Additionally, the ability to judge surface emotions and real emotions in either situation was found to increase with age. These results show how pretend/deceptive situations affect the ability to judge surface emotions and real emotions of children. This is important to expand the relevant theories of the theory of mind.
Evaluation method for hot rolling & run out table cooling parameters
Authors: Taylor T. , Sugiyama S. , Ishikawa A. , Wang H. , Yanagimoto J.
Published: December 2021

A new hot rolling & Run Out Table cooling simulator is constructed. The simulator permits continuous collation of process data including in-situ temperature measurement at numerous positions of the strip steel. Tensile properties and microstructural analysis of the hot rolled strip are correlated to the collated process data. A numerical model including phase transformation and latent heat evolution is constructed and calibrated against the experimental data. The resulting numerical model can be used to efficiently predict the optimal process parameters for manufacturing hot rolled strip steels, while the new hot rolling & Run Out Table cooling simulator can be used to efficiently validate the numerical simulation results before up-scaling to the industrial hot mill.
Use of effective dose to assess x-ray protective clothing
Authors: Eder Heinrich , Schlattl Helmut
Published: December 2021

This review article provides an overview on the results of studies conducted by the authors to improve the current personal protection concept in the clinical application of x-rays. With the aid of personal dose equivalent measurements during radiologically guided clinical interventions, laboratory tests using the Alderson-Rando phantom as well as Monte Carlo simulations various x-ray application scenarios were investigated. The organ doses and the effective doses of staff persons standing near the patient were determined. The 3D-attenuation properties of protective clothing under the scattered radiation emitted by the patient play a special role here. With regard to the minimisation of the quantity ‘effective dose’ the protection of the lower body from the gonads to the chest is of particular importance, since 80% of the effective dose is contributed by this region of the body. In contrast, protection of the back plays a subordinate role. Protective aprons optimised in terms of effective dose can be significantly lighter than conventional aprons, providing equal protection. The assessment of the attenuation properties of protective clothing should be based on the risk-related dose quantity, effective dose, rather than lead equivalent. In the future, the evaluation of radiation protective clothing could be based on the calculation of the effective dose assuming standardised irradiation conditions.
Curing monitoring of bonded composite patch at constant temperature with electromechanical impedance and system parameters evaluation approach
Authors: Zhu Jianjian , Wen Jinshan , Chen Chunyang , Liu Xiao , Lan Zifeng , Wang Yishou , Qing Xinlin
Published: December 2021

As one of cost-effective maintenance methods, bonded composite patch repair has been receiving more and more attention in the engineering community since past decades. However, realizing real-time monitoring for curing process of bonded repair patch is difficult for most current techniques. In our work, a method based on electromechanical impedance and system parameters evaluation for structural health monitoring issues was developed, which could implement the online monitoring throughout whole curing process. Compared with the dynamic thermomechanical analysis results, the experiment data matches well. It demonstrates that the proposed approach can effectively monitor the curing process of composite repair patch at a constant temperature of 120 °C. Hence, the presented approach in this paper is expected to be a novel, robust, and real-time monitoring method for structural maintenance with the composite patch.
BICEP/Keck and cosmological attractors
Authors: Kallosh Renata , Linde Andrei
Published: December 2021

We discuss implications of the latest BICEP/Keck data
release for inflationary models, with special emphasis on the
cosmological attractors which can describe all presently available
inflation-related observational data. These models are compatible
with any value of the tensor to scalar ratio r, all the way down
to r = 0. Some of the string theory motivated models of this class
predict 10-3 ≤ r ≤ 10-2. The upper part of this
range can be explored by the ongoing BICEP/Keck observations.
Lattice simulations of inflation
Authors: Caravano Angelo , Komatsu Eiichiro , Lozanov Kaloian D. , Weller Jochen
Published: December 2021

The scalar field theory of cosmological inflation constitutes nowadays one of the preferred scenarios for the physics of the early universe. In this paper we aim at studying the inflationary universe making use of a numerical lattice simulation. Various lattice codes have been written in the last decades and have been extensively used for understating the reheating phase of the universe, but they have never been used to study the inflationary phase itself far from the end of inflation (i.e. about 50 e-folds before the end of inflation). In this paper we use a lattice simulation to reproduce the well-known results of some simple models of single-field inflation, particularly for the scalar field perturbation. The main model that we consider is the standard slow-roll inflation with an harmonic potential for the inflaton field. We explore the technical aspects that need to be accounted for in order to reproduce with precision the nearly scale invariant power spectrum of inflaton perturbations. We also consider the case of a step potential, and show that the simulation is able to correctly reproduce the oscillatory features in the power spectrum of this model. Even if a lattice simulation is not needed in these cases, that are well within the regime of validity of linear perturbation theory, this sets the basis to future work on using lattice simulations to study more complicated models of inflation.
The PAU survey: measurement of narrow-band galaxy properties with approximate bayesian computation
Authors: Tortorelli Luca , Siudek Malgorzata , Moser Beatrice , Kacprzak Tomasz , Berner Pascale , Refregier Alexandre , Amara Adam , García-Bellido Juan , Cabayol Laura , Carretero Jorge , J. Castander Francisco , De Vicente Juan , Eriksen Martin , Fernandez Enrique , Gaztanaga Enrique , Hildebrandt Hendrik , Joachimi Benjamin , Miquel Ramon , Sevilla-Noarbe Ignacio , Padilla Cristóbal , Renard Pablo , Sanchez Eusebio , Serrano Santiago , Tallada-Crespí Pau , Wright Angus H.
Published: December 2021

Narrow-band imaging surveys allow the study of the spectral characteristics of galaxies without the need of performing their spectroscopic follow-up. In this work, we forward-model the Physics of the Accelerating Universe Survey (PAUS) narrow-band data. The aim is to improve the constraints on the spectral coefficients used to create the galaxy spectral energy distributions (SED) of the galaxy population model in Tortorelli et al. 2020. In that work, the model parameters were inferred from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) data using Approximate Bayesian Computation (ABC). This led to stringent constraints on the B-band galaxy luminosity function parameters, but left the spectral coefficients only broadly constrained. To address that, we perform an ABC inference using CFHTLS and PAUS data. This is the first time our approach combining forward-modelling and ABC is applied simultaneously to multiple datasets. We test the results of the ABC inference by comparing the narrow-band magnitudes of the observed and simulated galaxies using Principal Component Analysis, finding a very good agreement. Furthermore, we prove the scientific potential of the constrained galaxy population model to provide realistic stellar population properties by measuring them with the SED fitting code CIGALE. We use CFHTLS broad-band and PAUS narrow-band photometry for a flux-limited (i < 22.5) sample of galaxies up to redshift z ∼ 0.8. We find that properties like stellar masses, star-formation rates, mass-weighted stellar ages and metallicities are in agreement within errors between observations and simulations. Overall, this work shows the ability of our galaxy population model to correctly forward-model a complex dataset such as PAUS and the ability to reproduce the diversity of galaxy properties at the redshift range spanned by CFHTLS and PAUS.
Revisiting CMB constraints on dark matter annihilation
Authors: Kawasaki Masahiro , Nakatsuka Hiromasa , Nakayama Kazunori , Sekiguchi Toyokazu
Published: December 2021

The precision measurements of the cosmic microwave background power spectrum put a strong constraint on the dark matter annihilation cross section since the electromagnetic energy injection by the dark matter annihilation affects the ionization history of the universe.
In this paper, we update our previous simulation code for calculating the ionization history with the effect of dark matter annihilation by including Helium interactions and improving the precision of calculations.
We give an updated constraint on the annihilation cross section and mass of dark matter using the modified RECFAST code with the Planck 2018 datasets.
Duration-controllable mid-infrared pulse from bias-pumped Er:ZBLAN fiber laser
Authors: Wang Fuyong , Qin Zhipeng , Luo Jing , Zhou Xiudong , Li Bo
Published: December 2021

We experimentally demonstrate the generation of duration-controllable pulses at 2.8 µm based on bias-pump technique for the first time. Bias-pumped by a 976 nm continuous-wave (CW)-pulsed combined laser, duration-controllable pulses are produced from an Er:ZBLAN fiber laser and the duration is entirely determined by the duration of pump pulse. Numerical simulations agree with experimental results well, and further predict that the temporal profile of output pulse from bias-pumped Er:ZBLAN fiber laser can also be identical with that of pump pulse under certain conditions. The pump-controlled mid-infrared pulse may have more applications in various areas due to its manageable temporal characteristics.
Nonlinear Thomson scattering from a tightly focused circularly polarized laser with varied initial phases
Authors: Shi Yunxiao , Xu Zhe , Wang Jingyu , Huang Zehao , Liu Hui , Tian Youwei
Published: December 2021

Within the frame of classical electrodynamics, nonlinear Thomson scattering by an electron of a tightly focused circularly polarized laser has been investigated. The electron motion and spatial radiation characteristics are studied numerically when the electron is initially stationary. The numerical analysis shows that the direction of the maximum radiation power is in linear with the initial phase of the laser pulse. Furthermore, we generalize the rule to the case of arbitrary beam waist, peak amplitude and pulse width. Then the radiation distribution is studied when the electron propagates in the opposite sense with respect to the laser pulse and the linear relationship still holds true. Last we pointed out the limitation of the single electron model in this paper.
Chapter 5 Dark Matter and New Physics Beyond the Standard Model with LHAASO
Authors: Bi Xiao-Jun , Addazi Andrea , Belotsky Konstantin , Beylin Vitaly , Cirelli Marco , Esmaili Arman , Fornengo Nicolao , Gan Qing-Yu , Kachekriess Michael , Khlopov Maxim , Korchagin Vladimir , Korochkin Alexander , Kuksa Vladimir , Marciano Antonino , Neronov Andrei , Panci Paolo , Pasechnick Roman , Sakharov Alexander , Sala Filippo , Sciascio Giuseppe Di , Semikoz Dimiri , Dario Serpico Pasquale , Volchanskiy Nikolay , Yin Peng-Fei
Published: December 2021

In order to reveal the nature of dark matter, it is crucial to detect its non-gravitational interactions with the standard model particles. The traditional dark matter searches focused on the so-called weakly interacting massive particles. However, this paradigm is strongly constrained by the null results of current experiments with high precision. Therefore there is a renewed interest of searches for heavy dark matter particles above TeV scale. The Large High Altitude Air Shower Observatory (LHAASO) with large effective area and strong background rejection power is very suitable to investigate the gamma-ray signals induced by dark matter annihilation or decay above TeV scale. In this document, we review the theoretical motivations and background of heavy dark matter. We review the prospects of searching for the gamma-ray signals resulted from dark matter in the dwarf spheroidal satellites and Galactic halo for LHAASO, and present the projected sensitivities. We also review the prospects of searching for the axion-like particles, which are a kind of well motivated light pseudo-scalars, through the LHAASO measurement of the very high energy gamma-ray spectra of astrophysical sources.
Study of the initial stage of GaAs growth on FIB-modified silicon substrates
Authors: Eremenko M M , Shandyba N A , Chernenko N E , Solodovnik M S , Balakirev S V , Ageev O A
Published: December 2021

In this work, we studied the effect of the deposition thickness, growth rate, arsenic flux, and implantation dose on the morphology of the GaAs nanostructures grown on modified Si areas. It is shown that an increase in the growth rate at the initial stages of the growth process leads to the transition of the growth regime from layered-like to one-dimensional with the formation of nanowires. Studies of the effect of As4 pressure have shown that a change in the equivalent As4 flux in the range of 3.7 - 5.0 ML/s does not lead to any significant change in the structure of the GaAs layer in the modified areas. An increase in the implantation dose during processing with a focused ion beam led to disordering of the directions of the grown nanowires due to the degradation of the substrate crystal structure.
Self-consistent modeling of MBE self-catalyzed GaAs nanowire growth
Authors: Fedina S V , Koryakin A A , Fedorov V V , Sapunov G A , Mukhin I S
Published: December 2021

Self-catalyzed GaAs nanowires are synthesized by molecular beam epitaxy at various arsenic fluxes and growth temperatures. The growth of GaAs nanowires is simulated considering the kinetics of material transport inside the catalyst droplet. The re-evaporation coefficient of arsenic is estimated for the given growth conditions. Calculated nanowire growth rate is in satisfactory agreement with the experimental data.
Studying of a sensitive material based on Ecoflex and CNTs for flexible strain sensors
Authors: Demidenko N A , Kuksin A V , Davydova E S , Zaborova V A , Ichkitidze L P , Bordovsky S P , Gerasimenko A Yu
Published: December 2021

Nowadays there is a great need for the development of flexible strain sensors that can register human body’s movements. In the field of wearable and smart electronics such sensors are actively being developed. Resistive-type flexible sensors are the easiest to manufacture. Their mechanism of sensitivity to deformations is based on a change in electrical resistance during deformations. In this work, we have developed the functional material for strain sensor with high tensile properties, strength and electrical conductivity. This material based on a matrix of silicone elastomer and a multi-walled carbon nanotubes (MCNTs) filler. The material showed a high elongation of 950 % with a tensile strength of 1.437 MPa. The manufacturing process included laser structuring of MCNTs to form an electrically conductive network. The linear gauge factor was 3.4, and the angular gauge factor was 0.26.
Effect of the ultra-low arsenic flux on characteristics of In(As) nanostructures formed during droplet epitaxy
Authors: Kirichenko D V , Balakirev S V , Chernenko N E , Eremenko M M , Solodovnik M S
Published: December 2021

In this paper, we present the results of an experimental study of the influence of the ultra-low arsenic flux on the parameters of In nanodroplets obtained by droplet epitaxy on the GaAs substrate. We demonstrate that the arsenic flux can be used to alter the size of droplets without changing their surface density. An increase in the arsenic flux leads to a reduction of the nanostructure size or their complete decay. However, we demonstrate that certain growth conditions allow providing saturation of the size of nanostructures (∼30 nm) which ensures good reproducibility of the process. The mechanism of ring and hole formation at various arsenic fluxes is also discussed.
Nanoobject mass measurement using the node displacement of the second mode of the nanomechanical resonator
Authors: Solomonov N A , Novikova K N , Nadoyan I V , Mozharov A M , Shkoldin V A , Berdnikov Y S , Mukhin I S
Published: December 2021

This work suggests a new approach to weighting the nanoscale objects placed at the tip of cantilever vibrating inside the camera of scanning electron microscope. In contrast to traditional approach to mass determination, we suggest tracing the shift of the node of the second vibration mode as an alternative to frequency shift measurement. We demonstrate the applicability of our approach to carbon nanowhisker cantilevers grown on tungsten needles by focused electron beam induced deposition. We compare experimentally the performance of the suggested approach with the traditional frequency shift-based method.
Investigation of the effect of annealing on Si(100) substrate modified by Ga+ focused ion beam
Authors: Eremenko M M , Shandyba N A , Chernenko N E , Balakirev S V , Nikitina L S , Solodovnik M S , Ageev O A
Published: December 2021

In this work, we studied the effect of annealing the silicon surface on the morphology of focused ion beam modified areas. It was found that an increase in the ion beam accelerating voltage during surface treatment significantly affects the morphology and the appearance of the implanted material on the surface or its absence/evaporation during annealing. It is shown that an increase in number of ion beam passes leads to the formation of holes on the surface of the modified areas, which is a sign that significant damage to the substrate material has occurred.
Features of the MBE growth of nanowires with quantum dots on the silicon surface
Authors: Reznik R R , Kotlyar K P , Khrebtov A I , Cirlin G E
Published: December 2021

The development of a new semiconductor element base is necessary to create a new generation of applications. At present time, the synthesis of high-quality hybrid nanostructures based on III-V quantum dots in the body of nanowires of a wide range of material systems is an urgent and important task. In work hybrid III-V nanostructures based on QDs in the body of NWs in GaP/GaAs and AlGaP/InGaP material systems were synthesized in on silicon substrates and their physical properties were investigated.
Effect of wet chemical treatment on the properties of GaAs FIB-modified surface
Authors: Shandyba N A , Chernenko N E , Zhityaeva J Y , Osotova O I , Eremenko M M , Balakirev S V , Solodovnik M S
Published: December 2021

We present the results of studies of the effect of wet chemical treatment on the properties of a GaAs surface modified by a gallium focused ion beam. Our studies based on results of AFM, KpAFM and Raman spectroscopy measurements have shown that, during wet chemical treatment, the damaged areas disappear completely in the case of low accelerating voltages and small doses of ions. At the same time, large accelerating voltages lead to the formation of extended damaged regions, the complete removal of which requires a longer treatment or additional processing.
Separation of AlN layers from silicon substrates by KOH etching
Authors: Shubina K Yu , Mokhov D V , Berezovskaya T N , Pirogov E V , Nashchekin A V , Sharofidinov Sh Sh , Mizerov A M
Published: December 2021

In this work, the AlN/Si(111) epitaxial structures grown consistently by plasma assisted molecular beam epitaxy (PA MBE) and hydride vapour phase epitaxy (HVPE) methods were studied. The PA MBE AlN buffer layers were synthesized via coalescence overgrowth of self-catalyzed AlN nanocolumns on Si(111) substrates and were used as templates for further HVPE growth of thick AlN layer. It was shown that described approaches can be used to obtain AlN layers with sufficiently smooth morphology. It was found that HVPE AlN inherited crystallographic polarity of the AlN layer grown by PA MBE. It was demonstrated that the etching of such AlN/Si(111) epitaxial structures results in partial separation of the AlN epilayers from the Si(111) substrate and allows to form suspended structures. Moreover, the avoidance of surface damage and backside overetching was achieved by use thin Cr film as surface protective coating and by increasing the layer thickness accordingly.
MBE growth of AlGaAs/Ge/AlGaAs core-shell nanowire
Authors: Terpitskiy A N , Ilkiv I V , Kotlyar K P , Kirilenko D A , Cirlin G E
Published: December 2021

Heterostructured AlGaAs/Ge/AlGaAs core-multishell nanowires having hexagonal crystal structure were synthesized by molecular beam epitaxy. Formation of 2-3 nm Ge quantum well structure was demonstrated. Raman characterization revealed a 200 cm−1peak corresponded to hexagonal phases of germanium.
System for monitoring the parameters of overhead power lines
Authors: Listyuhin V A , Pecherskaya E A , Timokhina O A , Smogunov V V
Published: December 2021

The analysis of disturbances (accidents) on overhead power transmission lines and methods and means of the overhead power transmission lines parameters monitoring was carried out. It is shown that the most promising direction for ensuring the required indicators of the reliability of power supply is the development and implementation of information and measurement systems at the facilities of the power supply network complex. The structure of an intelligent information-measuring system for measuring parameters characterizing the state of wires, external factors influencing the state of power lines is proposed. The proposed decision support system will make it possible to promptly identify defective sections of overhead lines, increase the level of technological management of electrical networks.
The electromagnetic absorbers based nano - structured granular polymer-composites at gigahertz frequencies.
Authors: Savelev D , Grushevski E , Savinski N , Soloviev M , Turov V , Krenev V
Published: December 2021

The rapid increase in electromagnetic interference has received a serious attention from researchers who responded by producing a variety of radar absorbing materials especially at high gigahertz frequencies. Ongoing investigation is being carried out in order to find the best absorbing materials which can fulfill the requirements for smart absorbing materials which are lightweight, broad bandwidth absorption, stronger absorption etc. Therefore, this article introduces the electromagnetic wave absorption mechanisms and then reveals and reviews those parameters that enhance the absorption performance.
Design and simulation of the compact MEMS energy harvester based on aluminium nitride
Authors: Shlepakov P S , Uvarov I V
Published: December 2021

A device for converting the energy of mechanical vibrations to electricity by the piezoelectric effect is presented. A main part of the transducer is a multilayer cantilever with the inertial mass at the tip. A piezoelectric layer is made of 0.5 μm thick aluminum nitride. A feature of the device is the compact lateral size of about 1 mm, which is 10 times smaller in comparison with conventional harvesters. The device is fully compatible with microelectromechanical systems (MEMS) technology. The cantilever has a natural frequency of 45-160 Hz, depending on the size and inertial mass. The transducer generates the output voltage of 0.35 V, which is high enough for rectifying by the diode bridge. The output power of 2.7 nW is relatively low due to the small size. Nevertheless, the figure of merit is higher than that for conventional AlN-based energy harvesters.
High-performance inline RF MEMS switch for application in 5G mobile networks
Authors: Tkachenko A V , Lysenko I E , Kovalev A V , Vertyanov D V
Published: December 2021

This article presents the results of the design and analysis of a radio-frequency switch made using microelectromechanical systems technology. The device is the capacitive switch with a hybrid type of contact, in which the movable electrode of the structure – the metal membrane is part of the microwave signal line of the coplanar waveguide. The switch design is characterized by a high capacitance ratio and low contact resistance. The zig-zag elastic suspension is used to reduce the value of the pull-down voltage – 2 V and the switching time ∼ 7 us. The central resonant frequency of the switch is 3.8 GHz. In this case, in the open state, the value of the insertion loss is not more than -0.2 dB and the isolation value in the close state is not less than -55 dB. The effective frequency range is the S-band, as well as the C-, X- and Ku-band, in which the isolation value is at least -30 dB. The presented inline RF MEMS switch is suitable for use in various types of ground and satellite communications, in particular for devices and systems of 5G mobile networks.
The use of digital data processing to improve the metrological characteristics of the rubidium frequency standard
Authors: Valov A P , Arinushkina K G , Davydov V V , Rud V Yu
Published: December 2021

The necessity of improving the metrological characteristics of a quantum frequency standard when determining the coordinates of an object on the Earth’s surface or long-term transmission of large amounts of data in satellite communication systems is substantiated. A new algorithm for digital processing of optical signals in the frequency standard is proposed. The results of experimental studies of the metrological characteristics of a quantum frequency standard based on rubidium atoms - 87 are presented
Surface reconstruction post-processing method for 3D- scanned objects
Authors: Badillo P D , Parfenov V A , Shchegoleva N L
Published: December 2021

3D scanning is widely used in multiple applications to obtain high precision / non-destructive documentation of real-life objects, which is especially important in Cultural Heritage (CH) preservation. However, some issues (in particular missing parts which are commonly known as “holes”) affect the accuracy of the obtained 3D model after the scanning procedure and requires time-consuming post-processing procedures, which include manual editing by highly-trained personnel. In this article an automatic method to reconstruct the obtained surface of 3D models is proposed, improving previously obtained results for high-density point clouds.
Numerical modelling of non-planar GaN LED with CNT top contact
Authors: Raudik S A , Mitin D M , Vorobyev A A , Mozharov A M , Nasibulin A G , Mukhin I S
Published: December 2021

In this paper, the theoretical study of LED based on GaN NWs with carbon nanotubes (CNT) top contact has been presented. The main electrical and optical characteristics of LED have been numerically calculated. In a 0.5 x 0.5 mm NWs array, the Ohmic losses in CNTs were 2.7% with an operating current density of 50 A/cm2. It proves the possibility of using CNTs as transparent contact.
Spray deposited thin uniform NiO/Spiro-OMeTAD composite hole transport layer with top carbon nanotube electrode
Authors: Romashkin A V , Polikarpov Yu A , Silakov G O , Alexandrov E V
Published: December 2021

Thin Spiro-OMeTAD and NiO nanoparticles layers, as well as their composite layer was formed by layer-by-layer spray deposition as hole-transport layer (HTL), with followed carbon nanotubes (CNT) deposition to form Ti/TiO2/HTL/CNT structures. Layers’ uniformity was estimated by Raman intensity maps, AFM and current-voltage characteristics of the CNT layer and between CNT and Ti contacts. The possibility of formation of thin, less than 100 nm, pinhole-free uniform composite NiO/Spiro-OMeTAD layer by spray-deposition was shown, which manifests itself as continuous HTL even after top CNT layer deposition.
Laser treatment of ITO thin films with Carbon Nanotubes for Liquid Crystal Devices
Authors: Toikka A S
Published: December 2021

In this paper, the influence of laser ablation on the refractive properties of indium tin oxides (ITO) thin films with deposited single-wall Carbon Nanotubes (CNTs) was considered. Sputtering of CNTs was preliminary based on the laser-oriented method with application of the external electric field. The laser ablation of ITO-CNTs coatings allows changing the electric, optical and mechanical properties dramatically. Moreover, this technical operation permit to switch the topology of the surface, thus it leads to the conversion of the refractive index. The possibility of index-matching due to the laser treatment contributes to the expansion of the technical capabilities of LC devices.
Radiofrequency ablation of biological tissue and determination of the moment of achievement of the transmural effect: the influence of applied power on tissue resistance
Authors: Antipenko V V , Pecherskaya E A , Antipenko S A , Timokhina O A , Artamonov D V , Levin A I
Published: December 2021

Radiofrequency ablation (RFA) is used to treat both congenital and acquired heart diseases, including arrhythmias of various types. In this work, experimental studies are carried out on biological tissues under the influence of the applied power on the tissue. Based on the experiments carried out, it was concluded that the effectiveness of the effect on biological tissue and the quality of the result obtained clearly depend on the correct choice of power applied to the treated tissue.
Using of «bubble sensors» to control the quality of sequencing by the Illumina / Solexa method
Authors: Reznik V S , Kruglov V A , Davydov V V
Published: December 2021

In the modern world, sequencing is an integral part of medicine, biology and other scientific fields. The Illimina / Solexa method is a new generation method and relates to methods of mass parallel sequencing. One of the features of using this method is the sequential pumping of various chemicals through the flow cell in which the reaction occurs. For uniformity and high quality of DNA sequencing, it is necessary that the amount of gas in liquids be minimized. Because many it can adversely affect both during chemical reactions and at the stage of recording reaction results. This article will examine the sequencing system using the Illumina\Solexa method using bubble sensors. An algorithm was developed that periodically receives information from bubble sensors in a microfluidic tube. The information received is processed and allows at certain stages to report deviations from the normal conditions for sequencing. The experimental results are presented.
Identification of new silk-like protein from B. magister and development of functional materials based on it
Authors: Vronskaia A A , Mikushina A D , Eliseev I E
Published: December 2021

Tandem repeat proteins have composite structure and unique properties, which allow them to be used in multiple fields, such as soft photonics, drug delivery and textile industry. The recent discovery of squid ring teeth (SRT) proteins have expanded the existing repertoire of repetitive polypeptides. We chose previously unexplored squid B. magister for our research, isolated and analyzed a new protein forming its ring teeth and hooks, and amplified the corresponding gene. Finally, we used this new isolated SRT protein to fabricate transparent thin films and microspheres.
Combination of cytostatic chemotherapy with cisplatin and photodynamic therapy with Radachlorin reduced resistance of K562 and Hela cell lines
Authors: Klimenko V V , Shmakov S V , Knyazev N A , Verlov N A , Bogdanov An A , Terterov I N , Bogdanov A A
Published: December 2021

In this work were study combination effect of photodynamic therapy and cisplatin on the proliferation activity of K562 human leukemia cells and Hela cervical carcinoma cells. A decrease in cell viability and an increase the fraction of apoptotic cells for combination treatment compared with single therapy were observed. It has been shown that the G2/M-phase of cell cycle decreases compared with cisplatin treatment alone, which demonstrates an increase anti-proliferative effect. The combination index of the photodynamic therapy with Radachlorin and cisplatin was calculated and indicates a synergistic effect.
Passive decoy-state quantum key distribution with imperfect source
Authors: Gavrilovich A , Sych D , Kurochkin Y
Published: December 2021

Passive generation is a sophisticated way of state preparation in quantum key distribution (QKD) systems which is designed to exploit some internal physical process as a source of randomness. It can be profitable in a wide range of scenarios. However, the original analysis of the passive scheme implies an ideal interference which is almost impossible to assure in practice, therefore utilizing such method potentially compromises the security of the system. Here we develop a general technique to estimate decoy-state parameters for a passive protocol with an arbitrary experimental distribution of intensity. We compare this analysis with the original method and show that the proposed technique can provide higher key generation rates.
Formation of planar plasmon microstructures by dry aerosol printing
Authors: Khabarov K M , Nouraldeen M , Lizunova A A , Urazov M N , Ivanov V V
Published: December 2021

Optical properties and microstructure of samples formed by dry aerosol printing are studied. Silver nanoparticles flat layers of two types were formed on substrates surfaces and were investigated by a spectrophotometer, a scanning electron microscope, and a transmission electron microscope. It is shown that all microstructures support plasmon resonance on individual nanoparticles with the Q factor depending both on the width of the nanoparticles size distribution in the aerosol and on their tendency to agglomeration and aggregation.
Features of spectral analysis of nuclear magnetic resonance signal for express-control of hydrocarbon media
Authors: Makeev S S , Davydov V V , Rud V Yu
Published: December 2021

The article substantiates the need to study the structure of the nuclear magnetic resonance signal recorded using the modulation technique. For the stationary and current state, the characteristic features of recording a nuclear magnetic resonance (NMR) signal using the modulation method were determined. The influence of the properties of the medium on the features of recording the NMR signal has been determined. A new method is proposed for determining the contributions of absorption and dispersion signals to the recorded NMR signal. The features of the use of spectral analysis in the study of the NMR signal from hydrocarbon media have been determined.
Mass spectrometry analysis of C-dots produced by femtosecond laser irradiation of L-lysine film.
Authors: Astafiev A A , Gulin A A , Vasin A A , Shakhov A M , Zalessky A D , Osychenko A A , Nadtochenko V A
Published: December 2021

The production of carbon dots (C-dots) by femtosecond lasers within living cells and tissues is a novel approach, which has a great potency for intracellular bioimaging. An exact mechanism of fluorescent particles production as well as their composition still remains unknown. In this work we use L-lysine film as a model system to study the mechanism and the composition of C-dots produced by femtosecond laser irradiation investigated by time-of-flight secondary ion mass spectrometry (ToF-SIMS).
Simulating the spectral characteristics of reflection in planar porous structures with antireflection coatings ZnS/DyF3
Authors: Shishkina D , Shishkin I , Tishin P
Published: December 2021

This paper presents the results of modeling a planar multilayer structure with layers of porous silicon, ZnS and DyF3 coatings by the optical matrix method. It was shown that the optical matrix method, taking into account the model of porous silicon with a variable band gap, which takes into account the porosity gradient, allows us to approximate the course of the curve of the real experiment
Design and Simulation of the Two-Axis Micromachined Angular Rate Sensor
Authors: Lysenko I E , Denisenko M A , Isaeva A S
Published: December 2021

Micromechanical inertia sensors - accelerometers, gyroscopes, multisensor modules and systems based on them - are widely used in navigation, for compensation of other instruments (accelerometers, inclinometers) or stabilization (gyroscopes). The paper presents the designed construction of a MEMS angular rate sensor with two sensitivity axes, topology of gyroscope is presented; modal and static analysis is performed using ANSYS CAD; simulation results of micromechanical gyroscope operation under the action of angular velocities using VHDL-AMS are presented.
Determination of measurement fidelity for a superconducting photon-number resolving detector with micron-wide strips
Authors: Dryazgov M , Simonov N , Korneeva Yu. , Korneev A
Published: December 2021

We report a study of multiphoton detection fidelity (or accuracy) for sequential photon-number resolving detectors based on micron-wide superconducting strips. It was found that an increase in the width of the superconducting strips by a factor of 5 leads to an improvement in the measurement accuracy by more than a factor of 10.
Effect of encapsulation of fullerene in semiconducting zigzagcarbon nanotubes on optical and thermoelectric properties
Authors: Morozova E V , Timkaeva D A
Published: December 2021

We study the optical and thermoelectric properties of carbon nanotubes (CNTs) with encapsulated C60 fullerene molecules. Using ab-initio methods, we calculate optical and thermoelectric paramters for CNT with fullerenes periodically located inside the nanotube at different distances from each other. Dependencies of these parameters on fullerene concentration and diameter of CNT are analyzed.
Research of the structure and mechanical properties of gas-thermal coatings after induction heat treatment
Authors: Osipova E O , Markelova O A , Koshuro V A , Fomin A A
Published: December 2021

In this article the process of induction-thermal modification of titanium coatings formed by electroplasma spraying was considered. The influence of the inductor current on the temperature of processed samples was experimentally established. The research results showed that thermal treatment of the samples with titanium coatings at a temperature of 750–1200 °C and a duration of 300 s led to an increase in porosity from 56±2 to 61±1 % and in microhardness from 1035–1532 to 1825–1883 HV0,98, the sprayed layer thickness decreased from 320±30 to 114±15 μm as well. A change of nanoscale structural elements shape was also observed.
Al-CuOx multilayer nanostructures: formation features and thermal properties of new type of local heat source
Authors: Novoseltsev A I , Sorokina L I , Sysa A V , Ryazanov R M , Lebedev E A
Published: December 2021

In this work, multilayer nanostructured thermite materials are considered - a new type of local heat sources. Aluminium and copper oxide were chosen as components of the thermite mixture. The formation of multilayer structures was carried out on the surface of the substrate by the method of magnetron sputtering. The features of the deposition process as well as the energy properties of the formed materials have been investigated. The results obtained confirm the prospects of using this class of materials as local heat sources.
Application of the technology of induction chemical-thermal treatment to improve the physical and mechanical properties of tantalum
Authors: Voyko A , Gerasimov A , Fomina M , Koshuro V
Published: December 2021

The results of the chemical thermal treatment (CTT) of tantalum in a solid carbon- containing medium in the temperature range from 1000 to 1300 °C were presented. CTT consisted in heating a workpiece with a working medium in a container made of a refractory material. The induction heating method was used for heating. After strengthening treatment, tantalum samples were characterized by increased hardness, which grew from 140 to 1100 HV0.02.