bluuebunny/crossref_metadata_2025 huggingface dataset:
Emission properties and bidrifting subpulses in pulsar PSR J0815+0939
Authors: Han X. H. , Yuen R.
Published: March 2022

Context. We investigate the properties of the emission region in PSR J0815+0939 as revealed by the bidrifting subpulses.

Aims. We identify the emission properties as implied by different states of emission, including the charge density and the subpulse number on the carousel, in association with the different subpulse drift properties in bidrifting.

Methods. The investigation is based on the rotating carousel, incorporating the model for obliquely rotating pulsar magnetospheres of multiple emission states. For the subpulse drift velocity given by the electric drift, the latter changes as the emission state changes, resulting in the observed different drift-bands.

Results. Our results show that observable emission of this pulsar comes from two rotating carousels. The carousel at higher height is occupied by two different emission states. We find that the subpulse drift direction is different for emission coming either from different emission states on the same carousel or from similar emission states, but located on different carousels. We consider that establishing the subpulse number on a carousel may involve a mechanism that is not a function of the age or the obliquity angle of the pulsar. We discuss that bidrifting may be a common phenomenon, but its detection requires particular emission characteristics of the pulsar. We relate different subpulse drift modes in bidrifting with drifting subpulses of time-dependent drift rates, and speculate that they may be two manifestations of the same underlying mechanism.
Radial distribution of the carbonaceous nano-grains in the protoplanetary disk around HD 169142
Authors: Devinat Marie , Habart Émilie , Pantin Éric , Ysard Nathalie , Jones Anthony , Labadie Lucas , Di Folco Emmanuel
Published: March 2022

Context. HD 169142 is part of the class of (pre-)transitional protoplanetary disks showing multiple carbon nanodust spectroscopic signatures (aromatic, aliphatic) dominating the infrared spectrum. Precise constraints on the spatial distribution and properties of carbonaceous dust particles are essential to understanding the physics, radiative transfer processes, and chemistry of the disk. The HD 169142 disk is seen almost face-on and thus it offers a unique opportunity to study the dust radial evolution in disks.

Aims. We investigate the spatial distribution of the carriers of several dust aromatic emission features of the disk across a broad spatial range (10–200 AU) as well as their properties.

Methods. We analysed imaging and spectroscopic observations in the 8–12 µm range from the VLT Imager and Spectrometer for mid-Infrared (VISIR) at the Very Large Telescope (VLT), as well as adaptive optics spectroscopic observations in the 3–4 µm range from the Nasmyth Adaptive Optics System – Near-Infrared Imager and Spectrograph (NACO) at VLT. The data probe the spatial variation of the flux in the 3.3 µm, 8.6 µm, and 11.3 µm aromatic bands. To constrain the radial distribution of carbonaceous nano-grains, the observations were compared to model predictions using The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS), which is integrated into the POLARIS radiative transfer code by calculating the thermal and stochastic heating of micro-and nanometer-sized dust grains for a given disk structure.

Results. Our data show predominant nano-particle emission at all radii (accessible with our resolution of about 0.1″ or ~12 AU at 3 µm and ~0.3″, 35 AU at 10 µm) in the HD 169142 disk. This unambiguously shows that carbonaceous nano-grains dominate radiatively the infrared spectrum in most of the disk, a finding that has been suggested in previous studies. In order to account for both VISIR and NACO emission maps, we show the need for aromatic particles distributed within the disk from the outermost regions to a radius of 20 AU, corresponding to the outer limit of the inner cavity derived from previous observations. In the inner cavity, these aromatic particles might be present but their abundance would then be significantly decreased.
The damage effect of weld seam and groove area of titanium alloy with ceramic laser resistant coating
Authors: Zhu Jiemin , Zhao Yi , Yang Zhen , Cheng Gong , Luo Chuyang
Published: March 2022

In order to explore the effect of weld area and groove structure on the damage effect of laser irradiation on titanium alloy and ceramic coating, the experiment of continuous laser irradiation on welding seam and groove area of titanium alloy was studied, while the surfaces of the specimens were coated with or without anti-laser ceramic material. The following conclusions were obtained: the ceramic coating can protect the titanium alloy substrate from the damage of high power laser effectively; the laser resistance of ceramic coating on the welding seam area is weakened, but it still protects the titanium alloy effectively; the damage of laser on the edge and the corner structure of titanium alloy with groove structure is aggravated with the increasing of laser power density, and under the same laser density, the damage inside the groove is less than that outside, while that of corner is less than edge. Micromorphology results show that the ceramic coating undergoes a series of physical and chemical changes and phase transformation to absorb a large amount of thermal energy converted from luminous energy, which has a protective effect on the titanium alloy.
Fatigue reliability and sensitivity analysis of turbine disk with fuzzy failure status
Authors: Huang Xiaoyu , Wang Pan , Li Haihe , Zhang Zheng
Published: March 2022

Low-cycle fatigue is typical failure mode of aero-engine turbine disk, traditional reliability analysis method based on the binary state assumption has certain limitations for turbine disk reliability evaluation, because it doesn't consider the change of damage strength parameter caused by loading sequences and the enhanced damage by small load. On the basis of fatigue reliability analysis of the turbine disk, this paper considers the fuzzy state assumption of turbine disk, then select the membership function and indicate fuzzy failure probability of turbine disk, which can be transformed into a series of conventional failure probability by Gaussian quadrature. An active learning Kriging model is used to orderly calculate the failure probability corresponding to different limit state functions and the fuzzy failure probability of turbine disk. A global sensitivity index based on fuzzy failure probability is established to analyze the influence of input variables on the fuzzy failure probability, which is helpful to the reliability design and structural optimization of the turbine disk.
Genealogies of containment: migrant labour,bonifica integraleand bio-carceral regimes in an Italian agro-industrial enclave
Authors: Peano Irene
Published: March 2022

This paper begins from the present condition of migrant workers in the district of Foggia, south-eastern Italy, one of the largest agro-industrial enclaves in the country, employing tens of thousands of workers who live and labour in conditions of extreme precarity and exploitation. Techniques of containment of such labour force range from the spatial to the juridical and symbolic, through interlacing discourses and their material dimensions and outcomes, in which migrants are constructed as a security (and health) threat or a humanitarian emergency. Drawing on over nine years of engaged participant research and on archival and secondary sources, I reconsider the genealogies of such “dispositifs”, which date back to pre-unification projects of agrarian and penal reform and to the emergence of a racialist paradigm in the post-unitary Italian context, in relation to criminal anthropology. In particular, I examine their application to carceral regimes of labour in projects of land reclamation, which have shaped many agro-industrial enclaves (and especially that of Tavoliere, in the district of Foggia). The current materialities of migrant containment can thus be shown to bear the stratified, spectral traces of past projects and modes of governance.
Challenges to Gene Editing Approaches in the Retina
Authors: Bonillo Mario , Pfromm Julia , Fischer M. Dominik
Published: March 2022

Retinal gene therapy has recently been at the cutting edge of clinical development in the diverse field of genetic therapies. The retina is an attractive target for genetic therapies such
as gene editing due to the distinctive anatomical and immunological features of the eye, known as immune privilege, so that inherited retinal diseases (IRDs) have been studied in several
clinical studies. Thus, rapid strides are being made toward developing targeted treatments for IRDs. Gene editing in the retina faces a group of heterogenous challenges, including editing
efficiencies, off-target effects, the anatomy of the target organ, immune responses, inactivation, and identifying optimal application methods. As clustered regularly interspaced palindromic
repeats (CRISPR)/CRISPR-associated nuclease (Cas) based technologies are at the forefront of current gene editing advances, their specific editing efficiency challenges and potential
off-target effects were assessed. The immune privilege of the eye reduces the likelihood of systemic immune responses following retinal gene therapy, but possible immune responses must not
be discounted. Immune responses to gene editing in the retina may be humoral or cell mediated, with immunologically active cells, including microglia, implicated in facilitating possible
immune responses to gene editing. Immunogenicity of gene therapeutics may also lead to the inactivation of edited cells, reducing potential therapeutic benefits. This review outlines the
broad spectrum of potential challenges currently facing retinal gene editing, with the goal of facilitating further advances in the safety and efficacy of gene editing therapies.
Benefits and Shortcomings of Laboratory Model Systems in the Development of Genetic Therapies
Authors: Bucher Kirsten , Rodriguez-Bocanegra Eduardo , Fischer M. Dominik
Published: March 2022

Gene therapeutic approaches promise treatment or even a cure of diseases that were previously untreatable. Retinal gene therapies tested in clinical trials comprise a wide range of
different strategies, including gene supplementation therapies, in vivo gene editing, modulation of splicing mechanisms, or the suppression of gene expression. To guarantee efficient
transfer of genetic material into the respective target cells while avoiding major adverse effects, the development of genetic therapies requires appropriate in vitro model systems
that allow tests of efficacy and safety of the gene therapeutic approach. In this review, we introduce various in vitro models of different levels of complexity used in the
development of genetic therapies and discuss their respective benefits and shortcomings using the example of adeno-associated virus-based retinal gene therapy.
Von Balint in Sils in den 1960er Jahren bis zum Silser Balint-Seminar
im Coronajahr 2020
Authors: Mahrer Regine
Published: March 2022

Aus Anlass des 60jährigen Bestehens der Studienwochen in Sils im Engadin
erinnert die Autorin an die Entstehung und Entwicklung der jährlich
stattfindenden Balint-Studienwochen. Michael Balint war zwischen 1963 und 1970
fünf Mal anwesend im Engadin. Er demonstrierte den teilnehmenden
Ärzten und Ärztinnen die Spezifität der Balintmethode
und kreierte aus einer Notsituation heraus die
„Balint-Großgruppe“, um möglichst viele
Teilnehmer und angehende Leiter teilhaben zu lassen. Seine Methode wurde von den
nachfolgenden Studienleitern und Studienleiterinnen weitergetragen und
verbreitet, wobei das Verständnis und die Ausübung durchaus
verschiedene Formen annahmen. Die Quellen des vorliegenden Textes basieren auf
persönlichen Gesprächen, auf Artikeln, Archivmaterialien und
persönlichen Erinnerungen. Der Text wurde in der Vortragsform belassen,
um dem Leser und der Leserin eine Teilnahme an der Feierlichkeit des Anlasses
vom 12. September 2021 im Hotel Waldhaus in Sils Maria zu
ermöglichen.
Liebe Leser:in
Authors: Portwich Philipp
Published: March 2022

Mit dem Binnen-Doppelpunkt in meiner Anrede klingt ein Thema an, mit dem wir seit ein
paar Jahren konfrontiert sind: Gendergerechte Sprache ist ein Aspekt der
gesellschaftlichen Diskussion über Geschlecht, Gleichberechtigung und
Diversität. Und in dem Zusammenhang dürfen wir uns auch einmal
fragen: wie genderaffin ist die Balintarbeit und die Balint-Community?
Natürlich war Michael Balint ein Mann, aber wir wissen, dass für die
Entwicklung der Balintmethode seine Frau Enid ebenso maßgeblich war. In
unseren Fachgesellschaften sind es Männer wie Frauen, die die Balintarbeit
praktizieren und weiterentwickeln. Die IBF wird derzeit und nicht zum ersten Mal von
einer Frau präsidiert. Hier in der Schweiz hat im Herbst nach mehr als 10
Jahren die Präsidentin ihr Amt wieder an einen Mann übergeben und
die Silser Balintstudienwoche steht unter Leitung einer Psychiaterin.
Leserbrief zum Beitrag „Der zerrissene Kämpfer: Ein
Fahrradunfall mit Schädel-Hirn-Trauma (SHT)“
Authors: Eichfelder J.
Published: March 2022

Die Nummer 3/2021 des Balint-Journals ist unter dem Gesichtspunkt der
Psychosomatik als dem „Hiatus von Körper und Seele“
besonders eindrucksvoll geraten. Wird dieser im Artikel von Herrn Herzog auch noch
systemisch abgerundet, erscheint er bei Herrn Utech 1 auf dem körper-therapeutischen Gebiet sehr praxisnah im
Zusammenhang mit den angebotenen Übungen.
Public concerns and connected and automated vehicles: safety, privacy, and data security
Authors: Lee Dasom , Hess David J.
Published: March 2022

One dimension of the emerging politics of connected and automated vehicles (CAVs) is the development of public concerns over their societal implications and associated policy issues. This study uses original survey data from the United States to contribute to the anticipation of future policy and political issues for CAVs. Several studies have surveyed the public regarding CAVs; however, there are few studies that highlight the multidimensional public concerns that CAVs will most likely bring. The study breaks down the concept of “public” by showing that the demographic variables of gender, age, race, ethnicity, income, location (rural, suburban, urban), and political ideology (conservative, moderate, liberal) are significantly associated with three of the most salient public concerns to date (safety, privacy, and data security). Furthermore, the effects of demographic variables also vary across the type of policy issue. For example, women tend to be more concerned about safety than their male counterparts, and Hispanics (Latinx) tend to be more concerned about privacy than non-Hispanics. The research shows how the social scientific analysis of the “politics” of CAVs will require attention to the variegated connections between different types of public concern and different demographic variables.
Suspending solid particles in pendant liquid drops
Authors: Green Leigh Ann
Published: March 2022

Stable attachment conditions determined for a particle-fluid interface
Parasites in feral
Authors: Barton Diane P. , Fearn Simon
Published: March 2022

Feral populations of Chelodina longicollis (Shaw, 1794) have established in Tasmania but many aspects of their biology in the wild remain unknown. A number of C. longicollis specimens were available for examination for parasites. Two species of digenean parasites were found in three of the 11 turtles examined: a Choanocotyle sp. and Thrinascotrema brisbanica Jue Sue & Platt, 1999. This is the first report of parasites from feral turtles in Tasmania. Due to the lack of native populations of freshwater turtles in Tasmania, these parasites must also have been introduced to Tasmania and have established life cycles in the new environments. The implications of such introductions, without suitable definitive hosts available to assist in establishing parasite infections, is discussed. An updated list of digenean parasites reported from Australian freshwater turtles is presented.
Opposition to voluntary and mandated COVID-19 vaccination as a dynamic process: Evidence and policy implications of changing beliefs
Authors: Schmelz Katrin , Bowles Samuel
Published: March 2022

Significance

The challenge of securing adherence to public health policies is compounded when an emerging threat and a set of unprecedented remedies are not fully understood among the general public. The evolution of citizens’ attitudes toward vaccination during the COVID-19 pandemic offers psychologically and sociologically grounded insights that enrich the conventional incentives- and constraints-based approach to policy design. We thus contribute to a behavioral science of policy compliance during public health emergencies of the kind that we may increasingly face in the future. From early in the pandemic, we have tracked the same individuals, providing a lens into the conditions under which people’s attitudes toward voluntary and mandated vaccinations change, providing essential information for COVID-19 policy not available from cross-section data.
Using wǒmen (we) to mean s/he in Chinese parents’ interaction
Authors: Han Yanmei , Xiong Tao
Published: March 2022

Using the first-person plural pronoun wǒmen (we) to refer to a child (=he/she) is repeatedly
observed in Chinese parents’ interaction. To understand its interpersonal meanings, this study investigates this non-prototypical
pronoun use in Chinese parents’ community of practice. The analysis shows that the non-prototypical use of this pronoun not only
displays agency and connection between parents and children but also reveals the seemingly close but detached relationship among
parents. This non-prototypical pronoun use unveils the complex and dynamic nature of relational work. We argue for the
significance of community of practice in relational work studies, as it can proffer social and cultural contexts to pronoun use
and a situated understanding of interactants’ interpersonal relationships. The present study contributes to the documentation of
the non-prototypical use of wǒmen in Chinese contexts and the comprehension of its interpersonal meanings.
Ear-EEG compares well to cap-EEG in recording auditory ERPs: a quantification of signal loss
Authors: Meiser Arnd , Bleichner Martin G
Published: March 2022

Objective. Ear-EEG (electroencephalography) allows to record brain activity using only a few electrodes located close to the ear. Ear-EEG is comfortable and easy to apply, facilitating beyond-the-lab EEG recordings in everyday life. With the unobtrusive setup, a person wearing it can blend in, allowing unhindered EEG recordings in social situations. However, compared to classical cap-EEG, only a small part of the head is covered with electrodes. Most scalp positions that are known from established EEG research are not covered by ear-EEG electrodes, making the comparison between the two approaches difficult and might hinder the transition from cap-based lab studies to ear-based beyond-the-lab studies. Approach. We here provide a reference data-set comparing ear-EEG and cap-EEG directly for four different auditory event-related potentials (ERPs): N100, MMN, P300 and N400. We show how the ERPs are reflected when using only electrodes around the ears. Main results. We find that significant condition differences for all ERP-components could be recorded using only ear-electrodes. The effect sizes were moderate to high on the single subject level. Morphology and temporal evolution of signals recorded from around-the-ear resemble highly those from standard scalp-EEG positions. We found a reduction in effect size (signal loss) for the ear-EEG electrodes compared to cap-EEG of 21%–44%. The amount of signal loss depended on the ERP-component; we observed the lowest percentage signal loss for the N400 and the highest percentage signal loss for the N100. Our analysis further shows that no single channel position around the ear is optimal for recording all ERP-components or all participants, speaking in favor of multi-channel ear-EEG solutions. Significance. Our study provides reference results for future studies employing ear-EEG.
Photoacoustic microscopy visualizes glioma-induced disruptions of cortical microvascular structure and function
Authors: Gong Xinrui , Jin Tian , Wang Yongchao , Zhang Ruoxi , Qi Weizhi , Xi Lei
Published: March 2022

Objective. Glioma growth may cause pervasive disruptions of brain vascular structure and function. Revealing both structural and functional alterations at a fine spatial scale is challenging for existing imaging techniques, which could confound the understanding of the basic mechanisms of brain diseases. Approach. In this study, we apply photoacoustic microscopy with a high spatial-temporal resolution and a wide field of view to investigate the glioma-induced alterations of cortical vascular morphology, hemodynamic response, as well as functional connectivity at resting- and stimulated- states. Main results. We find that glioma promotes the growth of microvessels and leads to the increase of vascular proportion in the cerebral cortex by deriving structural parameters. The glioma also causes the loss of response in the ipsilateral hemisphere and abnormal response in the contralateral hemisphere, and further induces brain-wide alterations of functional connectivity in resting and stimulated states. Significance. The observed results show the foundation of employing photoacoustic microscopy as a potential technique in revealing the underlying mechanisms of brain diseases.
Electrode biasing maintains the edge shear layer at high density in the J-TEXT tokamak
Authors: Ke R. , Diamond P.H. , Long T. , Xu M. , Chen Z.P. , Gao L. , Yang Q.H. , Wang Y.H. , Zhang X.Y. , Nie L. , Wu T. , Gao J.M. , Li D. , Wang N.C. , Yang Z.J. , Chen Z.Y. , Pan Y. , Duan X.R.
Published: March 2022

Collapse of the edge flow shear as the line-averaged density approaches the Greenwald density limit has been observed as a precursor to the enhanced edge particle flux characteristic of proximity to the density limit regime. Here, we report the use of a biased electrode to sustain the edge shear layer in high density discharges, in which the shear layer would otherwise collapse. A stable increase in line-averaged density is observed along with a strong increase in edge density. These experiments were carried out on the J-TEXT tokamak. The Reynolds stress at the edge is enhanced, and the zonal flow sustained, while density perturbation levels, the flux of turbulence internal energy (i.e., turbulence spreading), and particle and heat flux all decrease significantly. Electron adiabaticity increases, and bias voltage modulation experiments show that an increase in the edge shear leads the increase in adiabaticity. These results suggest that external edge E × B flow shear drive may be of interest for sustaining edge plasma states at high density, and support the hypothesis that collapse of the edge shear layer triggers the onset of the strong transport and turbulence characteristic of the density limit regime.
Modeling of geometric correspondences and transformations via geometry constructions language
Authors: Boykov A A
Published: March 2022

Geometric correspondences and transformations can be applied in solutions to numerous problems of geometric modeling, mainly in order to create models of curves and surfaces. Among the tools of CAD systems, the geometric transformations are presented in the form of a limited set of editing tools, array tools, tools providing formation of 3D solids and surfaces through motion. In practice, this set of tools restricts application of the wide capabilities of geometric transformations and correspondences. In this regard, it is proposed to model the geometric transformations and correspondences via the geometry construction language. The elements of the geometric transformation theory are analyzed. The geometric transformations are proposed to be created on par with other objects of the geometric model. The commands of the geometry constructions language enabling construction of the transformation objects are considered, their application is discussed. Solutions to practical problems of surface modeling via the geometry constructions language with the use of geometric transformation are demonstrated on examples. The proposed approach allows us to facilitate modeling of curves and surfaces in CAD systems, if said curves and surfaces can be acquired through geometric transformation or correspondence that can be defined via a certain constructive algorithm.
Analysis of approaches to spline interpolation of functions with large gradients in the boundary layer
Authors: Blatov I.A. , Zadorin A I
Published: March 2022

The problem of cubic spline interpolation of functions with large gradients in the boundary layer is considered. It is assumed that the decomposition in the form of the sum of the regular and singular components is valid for the interpolated function. This decomposition is valid for the solution of a boundary value problem for a second order ordinary differential equation with a small parameter e at the highest derivative. An overview of approaches to the construction of splines, the error of which is uniform with respect to the small parameter e, is given. The approaches are based on the use of Shishkin and Bakhvalov meshes, which are thickened in the boundary layer region. An alternative approach based on a modification of a cubic spline with fitting to the singular component of the interpolated function is also considered. The comparison of the accuracy of the applied approaches with the performance of computational experiments is carried out.
Mathematical differential game model of a computer system and its defence against DDoS-attacks
Authors: Guts A K
Published: March 2022

The purpose of this article is a mathematical description of the DDoS-attack with the help of the differential game theory. The attacked computer system which has a performance limit is mathematically described. The hacker attack is successful if this limit is reached. The system administrator’s strategy is successful if he can prevent the server from “falling”. We find this strategy. Then we study an optimal Stackelberg strategies of hierarchial ”administrator–hacker” game.
Development of a model for determining the optimal number of urban passenger transport
Authors: Muhamediyeva D T , Mirzaraxmedova A X , Khasanov U U
Published: March 2022

The paper considers development of a model for determining the optimal amount of urban passenger transport. When modeling transport systems, the main task is to find the optimal amount of passenger traffic, which is a complex consisting of a mathematical model, an algorithm and a software product with information support for the integrated planning of the system of public transport routes and determining the rational volume of traffic.
Numerical simulation of water spray evaporation in a turbulent air flow
Authors: Nikitin M N , Satonin A V
Published: March 2022

Water spray evaporation in a hot air flow is a common process for many industrial applications. Spray nozzles should be well adjusted and distributed specifically to achieve efficient evaporation. The present study addressed simulation of the process within the Eulerian-Lagrangian workframe with k-∈ turbulence model. Simulation was carried out via OpenFOAM and postprocessed with ParaView. SprayFOAM solver was used to obtain a solution for 2D and 3D representations of the wind tunnel. Custom JANAF-based approximations were introduced for thermophysical properties of working mediums (air and water vapor). Obtained results were accurate enough to validate the presented model against adopted experimental data. Drift eliminator was modelled with virtual interfaces (baffles), which were tested in two scenarios: accumulating and removing droplets from the computational domain.
Optimal experiment design for locally adaptive regression models
Authors: Popov A A
Published: March 2022

The problem of reconstruction of dependencies using locally adaptive linear regression models is considered. The problem of a priori optimal design of experiments during identification of locally adaptive linear regression models is solved. In this case, the region of determining the active factors is divided into 2 or 3 fuzzy partitions. The problem of constructing D-optimal designs of experiment is formulated and solved
Recognition of the MNIST-dataset with skeletonized images
Authors: Shevlyakov A N , Lobanov V P
Published: March 2022

For a long time there have been many neural networks that are able to recognize handwritten numbers. In our work, we will investigate a neural network according to a specific feature, indicating the number in the picture. We will try to achieve an important image skeleton for recognition.
Synthesis of dynamics of nanosatellites with variable inertial-mass parameters
Authors: Doroshin A V , Eremenko A V
Published: March 2022

The work considers the dynamics of a composite nanosatellite with variable inertial-mass parameters. The nanosatellite consists of two units connected to each other by flexible rods, a main unit (nanosatellite body) and a mobile unit. A passive system for stabilizing the rotational motion of a composite nanosatellite is considered, which uses a mobile unit as a motion control actuating element.
Determination of the ion beam velocity of an accelerator two-gap ion thruster
Authors: Fedyanin V V , Vavilov I S , Yachmenev P S , Zharikov K I , Lukyanchik A I , Stepen’ P V
Published: March 2022

The article is devoted to the measurement of the ion beam velocity of an accelerator two-gap ion thruster. A theoretical representation of the physical process of capturing charged particles using a cylindrical sensing element is given. A schematic diagram and a printed circuit board for detecting an accelerated ion beam have been developed. The expression for calculating the signal current of the sensing element is defined. A condition for capturing charged particles using the critical mobility of charges is formulated.
The study of the deviations of the payload moved along the curved trajectory by the crawler crane
Authors: Korytov M S , Shcherbakov V S , Titenko V V , Belyakov V E
Published: March 2022

Reducing the uncontrolled deviations of the payload moved by a crawler crane with a constant boom length is a relevant objective, since it improves the operational efficiency and safety, as well as the positional accuracy of the payload at the target point. In this regard, the results of the research aimed at developing a trajectory synthesis method of two controlled coordinates of the crane, such as the swing angles of the rotary platform and boom raising which ensure a predefined trajectory of the moving payload, have been described. Furthermore, the influence of the payload movement parameters, such as the time of the prescribed payload displacement, the initial angle of the boom lift, the hoist rope length, the overall dimensions of the required payload displacement trajectory on the error of the predefined payload trajectory execution by the lifting crane has been studied. For example, we examined a predefined arc curved trajectory of the moving payload. The horizontal coordinates of the trajectory of the upper suspension point located on the boom head and providing the predefined payload trajectory were generated using the Matlab mathematical simulation model developed in the Simulink package for solving a linearized differential equation. This equation describes the deviations of a pendulum suspended payload with a horizontally moving suspension point in a separate vertically located plane of the space. The superposition of two horizontal trajectories obtained by solving the given equation ensures the payload movement along a curved trajectory predefined in the horizontal plane. The trajectory of the crane’s controlled coordinates was calculated from the horizontal coordinates of the suspension point. When executing the trajectory, the examined additional errors occur. It was revealed that when the time of moving along a predefined payload trajectory exceeds 40 seconds, the residual oscillations become insignificant and payload positional accuracy at the target point increases. It suggests the limited applicability of the developed method when implemented on the rotary lifting cranes with a constant boom length. The range of the local minima errors of the predefined trajectory implementation depending on the initial inclination angle of the boom, which varies in the average values range of the boom inclination angle, has been defined.
Use of the Belleville spring package in the vibration protection mechanism of the operator’s seat
Authors: Korytov M S , Shcherbakov V S , Titenko V V , Kashapova I E , Derkach V V
Published: March 2022

Reducing the vibration effects on the operator of a construction, road and other machines is a relevant objective, since its accomplishing improves the efficiency and accuracy of the work performed by machines and reduces the risk of operators’ occupational diseases. Vibration protection systems with the effect of quasi-zero stiffness are promising. To produce this effect, Belleville springs packages can be used. They are a way to create a simple, reliable and inexpensive passive mechanism of the vibration protection system of the operator’s seat. The influence of the static characteristic center slope of two Belleville springs packages on the maximum acceleration of the load under the sinusoidal kinematic excitation of the seat base movements is investigated. The static characteristic center slope of the spring packages was characterized by the coefficient that affects the type of the static characteristic according to the known analytical expressions for the separate spring force. To obtain the chair acceleration values in a fixed coordinate system, we used a simulation mathematical model developed in the Simscape Multibody package for modeling mechanical systems of the MATLAB mathematical system. The model used blocks of a fixed coordinate system, a sliding joint and a rigid body forming a chain. The maximum acceleration of the chair in a fixed coordinate system was defined during a predetermined period of time at the end of the transition process under the steady state oscillations. When conducting the computational experiment, the specified oscillations amplitude of the chair base and the angular frequency of these oscillations varied. For a proper comparison of the experimental results in the form of graphical dependencies of the maximum acceleration on the amplitude and frequency, the ranges of acceptable and unacceptable arguments combinations were selected for the two spring packages. The combinations of amplitude and frequency were considered unacceptable when the maximum deformation of the spring package went beyond the static characteristic maximum. For the two packages of springs, the acceptable regions were different, therefore their intersection used for the comparative analysis, was obtained. The springs package with a relatively high stiffness in the center of the static characteristic is found out to generally provide better vibration protection of the chair in the entire acceptable range of arguments. Simultaneously, a package with lower stiffness in the center of the characteristic dampens vibrations better in the small amplitudes area, i.e. when operating in the quasi-zero stiffness area.
Algorithm for the formation of the internal structure of a product manufactured using FDM technology, considering the stress-strain state on the example of four-point bending
Authors: Shalygin S V , Russkikh G S
Published: March 2022

The work is devoted to the description of an algorithm for the formation of the internal structure of a product, obtained using the FDM technology, considering the stress-strain state, based on the use of isosurfaces of equivalent stresses obtained on a pre-calculated stress-strain state of the sample in an elastic isotropic formulation. In addition, the preparation of a force structure based on isosurfaces of normal stresses, considering the problem of axial tension/compression of horizontal layers of the sample, typical for the problem of four-point bending, is described. Numerical simulations in ANSYS Workbench have obtained results showing the performance of the optimized design, using the example of the four-point bending problem. Comparison of the results of numerical modelling, optimized and monolithic samples, in elastic isotropic formulation is presented.
Evaluation of the efficiency of solid-phase activation of modifying complexes
Authors: Eremin E N
Published: March 2022

The efficiency of the solid-phase activation of modifying complexes has been evaluated. It is shown that such preliminary treatment of refractory particles leads to a significant increase in the diffusion coefficients in the matrix of the metal-ultrafine powder complex. The introduction of modifying complexes that have undergone solid-phase activation into liquid nickel increases the degree of supercooling of the melt and reduces the grain, which characterizes a high degree of intensity of the action of inoculators. In this case, the most intense effect is exerted by the addition of the TiCN-Ni and TiCN-Ti complexes that have undergone solid-phase activation.
Investigation of Ti/TiB2System Composite Coatings Sprayed by Microplasma Method
Authors: Goshkoderya M E , Bobkova T I , Staritsyn M V
Published: March 2022

The present work studies Ti/TiB2 system of metal matrix composite powders and coatings obtained on their basis by microplasma spraying. Ti/TiB2 is the system of potentially perspective materials being operated in aggressive environments. Morphology of the micro-grinding of the composite powder and coating was investigated by a scanning electron microscope, with the distribution assessment of the reinforcing component. The phase composition and its evolution in the composite powder and coating were also studied.
Influence of compositions ABRO GT-409 and POLYTRONMTC in transmission oil on tribological contact in material systems "CuCrNiZrTi - KCh50", "CuCrNiZrTi – 40X"
Authors: Kubich V I , Cherneta O G , Yurov V M
Published: March 2022

The work carried out definitive tribotechnical tests of the systems of materials "CuCrNiZrTi - 85W90 - 40X", "CuCrNiZrTi - 85W90 - KCh50" to assess the nature of the manifestation of the effect of additive compositions (AC) ABRO GT-409 and POLYTRONTMC on adaptability to loading and lubrication modes parameters of adhesion properties when modeling shear on small samples. It was found that at the stage of running-in, the systems of materials operate stably with clearly pronounced tendencies to reduce the sliding resistance to a certain minimum, followed by its increase due to the influence of the AC components. ACs do not determine the effect of reducing the wear intensity in the investigated range of contact pressures, and a decrease in friction is caused by a decrease in shear resistance in the zones of contact interaction of protrusions and depressions of surface irregularities. A more significant effect on the decrease in the parameters of adhesion properties is exerted by the POLYTRONMTC 10% AC components, which cause the formation of secondary lubricant formations with denser structures at the interface of adhesion with metal surfaces and reduced resistance to movement within the formed cohesive bonds between them.
The influence of titanium compounds on the electrophysical characteristics of the epoxy composite
Authors: Kukushina K G , Eremin E N
Published: March 2022

This article discusses influence of titanium compounds on the electrophysical characteristics of materials. Sequence of operations for receive the materials possessing improved radio-technical characteristics is shown. Material characteristics such as permittivity, shrinkage and hardness are described. Higher permittivity (ε) of composites is presented and subsequence and modes fabrication body parts of products. Facts are given that testify that the insertion is 30 % TiO2 raises permittivity by 1.4 times; interposition BaTiO3 in the same ratio - 1.7.
Investigation of the process and products of calcination of composite granules based on hydroxyapatite, wollastonite and gelatine
Authors: Solonenko A P , Shevchenko A E , Rozdestvensky A A , Dzyuba G G
Published: March 2022

Control of the composition after heat treatment is important stage of biomaterials production especially in case of their new versions creation, because many biocompatible synthetic substances are unstable at high temperatures. Interaction between components in multicomponent systems is possible with the formation of new undesirable products. In this work, the process of calcination of composite granules with a variable content of hydroxyapatite and wollastonite and binder polymer (gelatine) was studied. It was found that materials heat treatment leads to a change of their phase composition caused by the apatite decomposition, transition of β-CaSiO3 to α-form, and calcium silicophosphate formation (in samples where apatite is the main component). Calcined products composition depends on the apatite/wollastonite ratio in the materials.
Numerical study of nitrogen bulk dissociation in DC magnetron discharge in Ar+N2 mixture
Authors: Strunin V I , Lyakhov A A , Khudaibergenov G Zh
Published: March 2022

The effect of the composition of the gas feed mixture on the dissociation rate constant of molecular nitrogen is examined by numerical solving the Boltzmann equation written in a two-term approximation for conditions corresponding to nitride aluminum films deposition. By solving of macroscopic balance equations in volume occupied with plasmas of stationary low-pressure glow discharge in a nitrogen-argon mixture the atomic nitrogen density was determined. It’s shown that there is a maximum of atomic nitrogen density at certain stoichiometry of gas feed mixture.
Determination of the Mandelstam – Brillouin Scatter Frequency Characteristic in Optical Fibers of Various Types
Authors: Bogachkov I V , Gorlov N I
Published: March 2022

The results of researches of the Mandelstam – Brillouin scattering frequency characteristics in single-mode optical fibers of various types are presented in this paper. A technique for obtaining the spectral characteristics of Mandelstam – Brillouin scattering for predefined acoustic mode distributions in single-mode optical fibers is considered. The procedure for determining the frequency characteristics of the Mandelstam – Brillouin scattering for a given structure of the radial distribution of the optical fiber refractive index is discussed. The Mandelstam – Brillouin scattering frequency characteristics of single-mode optical fibers obtained by mathematical modeling and experimental studies are presented. A comparative analyze of obtained results is carried out.
Determination of the thrust of an ion thruster by the aerodynamic method of double angle (AMαβ-method)
Authors: Vavilov I S , Yachmenev P S , Zharikov K I , Fedyanin V V , Lukyanchik A I , Stepen’ P V
Published: March 2022

This paper presents the results of an experimental study of the jet thrust of a mixed jet of neutral and ionized nitrogen flowing from the working chamber of an experimental sample of an accelerator ion thruster into a vacuum space. The main method of the study was the aerodynamic double angle method (AMαβ-method). The method of determining low thrust and the design of the stand for the implementation of the AMαβ-method are proposed. The object of research is a prototype of an accelerator two-phase ion thruster with a solid-state microwave plasma generator and a toroidal resonator. The study showed that a 2.5 W microwave generator together with a 2.5 W accelerating potential difference voltage source with a nitrogen consumption of 0.05 -1 mg/s can increase the speed of the working gas by 2.3 times. The jet thrust, according to the test results, was 1-3.6 μN. It is shown that the thrust components (the gas-dynamic component, the ion component of a high-frequency discharge, the ion component of a glow discharge) have different levels depending on the mass flow rate of the gas.
Procedure of sample preparation for international and interlaboratory comparisons in the field of the pH measuring of borate buffer solution
Authors: Prokunin S V , Vengina D A , Dobrovolskiy V I , Oganyan N G , Shchipunov A N
Published: March 2022

In the paper is discribed the preparation method of buffer solution for interlaboratory and international comparisons. This technique was developed by scientists of All-Russian Scientific Research Institute of Physicotechnical and Radio Engineering Measurements during the preparation of samples for international comparisons in the field of measuring the hydrogen index of borate buffer solution. According to the measurement results, the offered method allows to prepare the homogeneous and stable buffer solutions.
Quantum standards for electrical and electro-chemical measurements
Authors: Sherstobitov S V , Karpova M V
Published: March 2022

The paper considers the current trends in the development of standards in the field of electrical measurements. The principles of constructing mutually consistent standards and reference complexes using quantum effects and fundamental constants and necessary for reproducing units of quantities used in the fields of electrical, physical-technical and radio-technical measurements, which are also the basis for electro-chemical measurements, are formulated. The results of theoretical and experimental studies aimed at developing possible methods for constructing and implementing ways of quantum standards and reference complexes that implement the principle of mutually consistent reproduction of the basic units of electrical quantities with reference to quantum effects and fundamental constants in accordance with the new definitions of the SI system are presented.
Problems of metrological support of Raman spectroscopy
Authors: Levin A D , Filimonov I S , Ivanov A V , Alenichev M K
Published: March 2022

The development of Raman spectroscopy metrology is discussed. The modern efforts in this field are directed towards the support of quantitative analysis of substance concentration in volume and surface layers.