bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel multidimensional biomarkers for non-invasive medical diagnostics
Authors: Vonsky M S , Runov A L , Moiseeva O M
Published: November 2019

Value of clinical laboratory diagnostics results are often underestimated in medical practice due to the fact that result of laboratory analysis in most cases represents a single biomarker of the organism homeostasis complex pathological alteration. New systemic approaches emerging on the basis of Omic’s knowledge and techniques allow development of multidimensional biomarkers, reflecting multiple pathobiological axes which characterize defined pathological condition. Combination of liquid biopsy technology with multidimensional biomarkers allows to obtain clinically valuable personalized information on the patient by non-invasive approach even for hard-to-reach organs and tissues.
An acoustic pressure pipette aspiration method for isotropic materials
Authors: Maghzinajafabadi M , Lamprecht R , Döllinger M , Semmler M , Sutor
Published: November 2019

A measurement setup is presented as a method to determine the elasticity modulus of both artificial and real tissue as a function of frequency. The future goal at the end is to develop and validate the method to measure the elasticity modulus of ex vivo cadaver animal vocal folds over the human phonation frequency range. In the present study, we investigate an innovative acoustic pressure pipette aspiration technique to measure the material characteristic of an isotropic silicone specimen with similar characteristics as human vocal folds. With the aim of ensuring reliable results, we test our method on different mixtures of silicone rubber. Four silicone samples with different consistencies were tested over a frequency range of 50 –500Hz. Influence of vibrometer laser spot location in an enclosed area on the sample surface was investigated by repeating the measurements ten times. The results show only small standard deviations demonstrating the potential of the acoustic pressure pipette aspiration technique for material characterization.
The status of the concept of reference object in measurement in the human sciences compared to the physical sciences
Authors: Wilson M , Mari L , Maul A
Published: November 2019

For measurement in the human sciences, one barrier to being able to see the commonalities with measurement in the physical sciences has been the common prominence that is often given to the important place that “reference objects” are given in introductory accounts in metrology. The obvious difficulties in having such objects, say, “reference humans,” makes it difficult to build connections. In this paper, we outline a way to broaden the concept of a reference object in way that addresses this issue. In this light we then discuss the recent developments in the International System of Units (SI), and comment on certain similarities.
Interpreting the relationship between item difficulty and DIF: examples from educational testing
Authors: Wilson M , Dulhunty M
Published: November 2019

The investigation of differential item functioning (DIF) is commonplace in educational testing. Most often it results in no more than the discarding of a proportion of the developed items. Apart from the potential threat to validity of the instrument due to differential loss of certain types of items, this also is inefficient in terms of item development costs. This paper discusses certain situations where particular patterns of non-uniform DIF can be related to item difficulty, and modelled by enhanced Rasch models. This allows for a more efficient usage of items, as well as, potentially, an improved understanding of the complexities of how educational tests function across different sub-populations.
Upper limbs biomechanics: drinking evaluation protocol in hemiparetic patients
Authors: Crenna Francesco , Bergamino Camilla , Ponte Chiara , Simonini Marina , Rossi Giovanni B
Published: November 2019

Biomechanical measurements applied to upper limbs gesture, characterisation and clinical evaluation are less diffused than lower limbs evaluation where gait analysis is rather common. When dealing with upper limbs a set of critical problems have to be afforded. In walking analysis we know that the movement is cycled and repeatable, instead upper limb gestures are more complex principally because of lack of the periodicity. In this paper we present a protocol to face such problems and obtain an objective biomechanics evaluation of the upper limbs, with the particularity to be focused on a daily life gesture such as drinking. The experimental protocol is presented together with the parameter identified to characterise the movement. Some preliminary results are discussed with reference to a set of healthy and clinical subjects.
Squat biomechanics in weightlifting: foot attitude effects
Authors: Crenna Francesco , Battista Rossi Giovanni
Published: November 2019

Squat weight lift is a common exercise in physical training used both in weightlifters specific training and in general athletes for leg force increment. When weight load on subject shoulders is rather heavy as compared with full body weight, gesture biomechanics becomes critical, since injuries may occur when gesture is not controlled or performed in a wrong way. Experienced trainers are aware of such issues and give proper instructions to obtain best performance at a minimum injury risk. In this work a quantitative approach is presented, supported by biomechanical measurements to determine the effects on main articulations of different postures during the exercise. Preliminary results confirm good practices giving a quantitative indication of joints solicitations.
Comparing a compact hematology analyzer based on direct optical measurements using blue LED with the VCS reference technology for neutrophil differential count
Authors: Lorenzon V M , Costa Monteiro E
Published: November 2019

Technologies for the automated blood cell count have been evolving over the last decades. Hematology analyzers enable identifying blood elements, including leukocytes differential. In the bloodstream, the most abundant leukocyte, the neutrophil, presents multi-lobed nuclei, requiring, therefore, combined measurement principles for their detection and classification. Due to the lack of white blood cells’ certified reference materials or reference measurement method, it has been customary to evaluate the performance of new hematology analyzers by comparing them with traditionally available and well-consolidated systems. In 2015, a technology based on axial light loss using a blue LED, the Beckman Coulter DxH500, was launched. This hematology analyzer presents reduced cost, fewer chemical reagents, and a compact design. This work compares the performance of the DxH500 with an analyzer frequently employed in large-scale laboratory routine, the Beckman Coulter LH750, based on the well-established combination of volume (impedance), conductivity and light scatter principles. The study examined 310 paired samples taken out randomly from the routine of a general hospital laboratory. The analyses evaluated the correlation coefficient, p-value, and the linear regression equation. The equivalence of results provided by both analyzers for the characterization of neutrophils in the leukocyte population points to the performance adequacy of the new low-cost and portable technology, suitable for small-sized clinical laboratory’s routines.
Musical instruments for the measurement of autism sensory disorders
Authors: Benoit E , Perrin S , Donnadieu S , Dascalu C , Mauris G , Favory J , Dautremer C
Published: November 2019

The analysis of sensory disorders in children with autism is a long process based on the observation of children in a specific environment. It cannot be treated frequently and monitoring the evolution of sensory disorders is either impossible or limited to a period of more than one year. The objective of our study is to define and then use dedicated musical instruments to perceive the intensity of children’s responses to different stimuli in order to measure their sensory disorders.
Towards biological quantity theory for nominal property metrology in polyenzymatic devices with living cells
Authors: Belobrov P I , Evstrapov A A , Esimbekova E N , Denisov I A , Lukyanenko K A , Osipova E D , Yakimov A S
Published: November 2019

Here we discuss the concepts of “biological quantity” and “nominal property” within the framework of the problem of biological measurements based on new specific results of biological analysis using a microfluidic platform and chips developed by our team earlier. It was shown that based on different microfluidic platforms it is possible to develop chips with a polyenzymatic bioluminescent system NAD(P)H:FMN-oxidoreductase-luciferase (Red + Luc), which can be used in various areas of biological analysis. Thus, disposable microfluidic chips with Red + Luc system suitable for field and indoor use were developed using continuous flow microfluidic platform. The use of droplet-based microfluidic platform allowed to develop microfluidic chips with Red + Luc system for long-term continuous measurements of water samples, for example, in places of waste disposal by industrial enterprises. The reference for comparing different biological quantities with each other in the proposed system was a photodetector, which converted non-numeric values and nominal properties recorded by a biological module Red + Luc into numerical variables. Such a reference was implemented as a portable luminometer based on silicon photomultiplier. The results allow to perform other biological measurements and to start the discussion of modern biological concepts in the language of biological measures.
Metrologically coherent assessment for learning: what, why and how
Authors: Pey-Tee Oon Emily , Hoi-Ka U , Fisher Jr W P
Published: November 2019

Assessment for learning aims to improve learning by feeding back information on the attainment of intended learning objectives to students and teachers. In this form of assessment, the student acts as a measuring instrument and learning attainment is the quantity to be measured. Current practices in classroom assessment, unfortunately, often are not grounded and have been focused on total correct scores without reference to the evidence hidden within them concerning the attainment of learning objectives. Our goal in this study is to clarify what assessment for learning is, why it is important, and how it works in a metrologically coherent context of equated assessments administered from calibrated item banks. The main focus lies in how item content can be framed according to intended learning outcomes that are meaningfully interpreted using a construct map. An example involves empirical datasets of 283 secondary three students from two formative tests designed by two science teachers. Coherent formative assessment of this kind applies a scientific model that belongs to the same class metrologists consider as defining measurement. The results illuminate the potential for establishing item banks that enable teachers to more efficiently and effectively assess and improve the attainment of learning objectives across different cohorts of students in a common metric.
Coherence in measuring student evaluation of teaching: a new paradigm
Authors: Huang Fan , Pey-Tee Oon Emily , Fisher Jr W P
Published: November 2019

Student Evaluations of Teaching (SET) have been adopted worldwide as a standard practice to enhance teaching and learning quality. However, improvement efforts are threatened by various problems involving ordinal scores and interpretive frameworks restricted to individual item sets and uninformed by a well-defined invariant construct. In this study, an approach to framing SET items according to theory rather than personal or subjective decisions is described. A sample of 920 students from the University of Macau participating in this study provided responses to 42 SET items. Applying a scientific model of measurement, the data collected were analysed and interpreted. Justification between theoretical and measurement analysis informed the creation of a theoretical SET construct map. That map and the associated item hierarchy were used as reference sources for configuring SET reports and recommendations. A new coherent paradigm for SET documentation is proposed for further study.
Actual metrological and legal issues of non-destructive testing
Authors: Gogolinskii K V , Syasko V A
Published: November 2019

The article is devoted to analyzing problems of metrological support and legal regulation in the sphere of non-destructive testing (NDT). Differences between the measurement technique and NDT have been analyzed. The necessity to apply the principles of metrological traceability to the NDT technique, equipment and test pieces has been announced. It has been suggested to view NDT as multi-parameter measurements. An example of the reference measuring system for complex calibrations of metal coatings measures on metal bases to calibrate eddy-current thickness gages of coatings has been given.
Modelling and optimisation of design of non-conventional instrument transformers
Authors: Nikolić Bojan , Khan Sanowar
Published: November 2019

In this paper, we have proposed, modelled and optimised several designs of non-conventional instrument transformer (NCIT) for high voltage overhead transmission lines (400kV). We have discussed several parameters and investigated how they influence the sensitivity of our NCIT, consisting of magnetic shape memory (MSM) element, magnetic circuit and an LVDT (linear variable differential transformer). One of the most used conductors in these lines, 528-Al1/69-ST1A ACSR conductor (old code MOOSE), was modelled together with the MSM element and the magnetic circuit in ANSYS APDL. Based on the obtained results we have given suggestions on how NCIT could be designed taking into account a choice of the most appropriate material for this application. The way how the model was developed was presented as well as calculations of errors in the model in ANSYS APDL for electromagnetic problems.
The feasibility of using an international common reading progression to measure reading across languages: a case study of the Vietnamese language
Authors: Nguyen C
Published: November 2019

In the last few decades, student achievement in many countries has been assessed and reported against a developmental learning continuum which underpins the knowledge and skills being measured. There have been efforts to place students from different countries on the same scale. However, those efforts have often been limited to individual projects and countries. There has been no common framework and no common metric for assessments to be compared across countries and levels. Recently, the UNESCO Institute for Statistics (UIS) has worked with the Australian Council for Educational Research (ACER) to develop UIS reporting scales for reading and mathematics with the aim of enabling countries to examine and report using a common framework and common quality control. This paper presents the results of an evaluation of the feasibility of adapting and applying the UIS reporting framework to the reading of Vietnamese language.
Direct measurement of stationary objects’ dimensions with Michelson type incremental laser interferometer
Authors: Stejskal T , Dovica M , Ď uriš S , Ď urišová Z , Palenčár J
Published: November 2019

The paper deals with a design of an original length measuring equipment for a measurement by Michelson-type laser interferometer. Laser measuring operate on the principle of relative movement of two components, where one component is fitted with an interference unit and the other one with a reflector. Such system is capable of measuring the length of displacement post motion, however, it is unable to measure the length of a stationary object. Functionality of the measuring equipment is ensured by a measuring board and a ruler. At a relatively low additional cost, the measuring configuration is capable of measuring the lengths of motionless objects achieving the precision of laser. The paper describes the measurement methodology verified in an experiment. Expanding verification tests of the device may facilitate possible commercial production of such auxiliary device for the Michelson-type laser interferometer, which would make the symposium motto “The future glimmers long before it comes to be” sound especially true.
A seismocardiography system and a possibility of its use for diagnosis of internal organs diseases using seismocardiogram information analysis
Authors: Uspensky V M , Achildiev V M , Bedro N A , Soldatenkov V A , Gruzevich Y K , Evseeva Y N , Komarova M N , Levkovich A D
Published: November 2019

The work is devoted to the development of a cardioseismometer system for obtaining a seismocardiogram for informational analysis of seismocardiographic signals and diagnosis of internal organs diseases on their basis. The cardioseismometer system allows measuring angular velocity projections and the vector of apparent acceleration recorded on the chest due to the mechanical movement of the heart, calculation of heartbeat acceleration vector - magnitude and direction relative to the reference coordinate system. The most informative and available for high-precision measurement parameters of seismocardiographic signals are selected, which are compared to the parameters of the electrocardiograms measuring model used to diagnose diseases. The conclusion was made about the possibility of using the dynamics of the seismocardiographic signal main parameters for informational analysis to diagnose diseases of internal organs. Experimental research results are given.
Modelling IoT technology for a cargo port
Authors: Postolache O , Yang Y , Zhong M , Yao H , Yu F , Fu X , Mi C
Published: November 2019

A work on modelling Internet of Things architecture for cargo ports is described. The main things and their roles in a cargo port, different sensors and instrumentation that was used or might be used for sensing and control in a cargo port, and some examples of IoT technologies that might contribute for improving the safety of processes and the security of the port are presented. By increasing the accessibility and accuracy of relevant information, IoT technologies may increase efficiency and quality of services in cargo ports, the operational safety and security of the ports.
Problems and prospects of complex psychological phenomena measurement
Authors: Kostromina S , Gnedykh D
Published: November 2019

The article is dedicated to the key problems of complex psychological phenomena measurement: the difficulties of measurement systems correspondence in the evaluation of the psychological phenomenon by qualitative and quantitative measurement methods; the difficulties in the comparability of the measurement results in psychological phenomena studying. The problems that arise in the methodology of psychological science and in the organization of interdisciplinary research are discussed. In conclusion, the direction of solving the described problems aimed at joining efforts of psychologists and metrologists is proposed.
Calculations of anisotropic distribution function of fast particles in plasma of the Globus-M spherical tokamak using the NUBEAM code
Authors: Kiselev E O , Bakharev N N , Goncharov P R , Gusev V K , Khromov N A , Kurskiev G S , Melnik A D , Minaev V B , Miroshnikov I V , Patrov M I , Petrov Yu V , Sakharov N V , Schegolev P B , Telnova A Yu , Tokarev V A , Tolstyakov S Yu , Tukhmeneva E A
Published: November 2019

The results from calculations of the anisotropic fast particle distribution function in the Globus-M/M2 spherical tokamaks are presented. The calculations were performed using the NUEBAM code, the reasons for the anisotropy occurrence are discussed (injection geometry, low toroidal magnetic field and plasma current, presence of neutral particles). It is shown that the anisotropy decreases with increasing toroidal magnetic field and plasma current: the density of the slowed down fast ions with energies of E < 4 keV almost doubles and the averaged perpendicular velocity of fast ions increases.
Radial structure of quasi-coherent mode in ohmic plasma of the T-10 tokamak
Authors: Drabinskiy M A , Eliseev L G , Khabanov P O , Melnikov A V , Kharchev N K , Sergeev N S , Grashin S A
Published: November 2019

The paper presents the recent results from the quasi-coherent (QC) mode studies performed in the ohmic plasma of the T-10 tokamak (R = 1.5 m. a = 0.3 m, B
0 = 2.2 T, I
pl = 230 kA, and n
e ≈ 1⋅1019 m−3) using Heavy Ion Beam Probe diagnostics (HIBP). The radial distribution of the amplitude of the density perturbations caused by the QC-mode has two pronounced peaks (approximately 5 and 1.5 % at radii of 25–30 and 8–14 cm, respectively) with an intermediate zone of lower amplitude in between them (<1% at radii of 16–21 cm). The mean QC-mode frequency remains nearly constant within the studied region (75–80 kHz). For the edge plasma, the HIBP observations were confirmed by the Langmuir probe measurements.
Spontaneous drop of the Li-containing flake as a trigger of ITB-event in plasmas of the T-10 tokamak during simultaneous co+counter injection of EC waves
Authors: Neudatchin S V , Pimenov I S , Borschegovskiy A A , Kislov A Ya , Kuyanov A. Yu.
Published: November 2019

Various triggers of ITB-events (ITB-event is an abrupt and non-local reduction of the heat flux within a radius of ∼50% of the minor radius) have been previously found at the JT-60U, the T-10 tokamaks and the LHD stellarator. This short paper describes a new trigger of ITB-events discovered in the T-10 plasmas in experiments on simultaneous co+counter axial EC current drive performed using the X-wave with a frequency equal to the second ECR harmonic. In these experiments, the tungsten limiter and lithium wall coating were used. The ionization of atoms in the Li-containing flake, which occurs at the plasma edge, generally causes the rise of the electron temperature and density in the core of the plasma column. The electron heat flux reduces abruptly within the radial range of 0.2 < r/a < 0.8, just as it was at the LHD in experiments on the injection of small C8H8 pellets. The energy confinement time abruptly increases by ∼10%. After the transient phase, the ITB appears, which is located between the radii corresponding to the safety factors of q = 1 and q ≈ 1.4. Typically, the ITB lifetime is equal to the plasma energy lifetime. As far as we know, the triggering of ITB-events by the drop of Li-containing flake has been never reported in tokamaks and stellarators.
Probing ion trajectory simulations for the HIBP diagnostics at the T-15MD tokamak
Authors: Ilin A M , Khabanov P O , Melnikov A V
Published: November 2019

The paper presents the results of preliminary simulations of the Tl+ ion trajectories and detector grids for Heavy Ion Beam Probe (HIBP) diagnostics at the T-15MD tokamak. For these calculations, authors have developed the HIBP SOLVER software package using the Runge-Kutta method of the 4th order for solving the motion equation for the probing particles. Simulations have shown that the HIBP diagnostics at the T-15MD tokamak will allow measuring the entire radial profile of the plasma potential during one shot, including both the core and edge regions. The detector grid covers the most area of the vertical plasma cross section, so the two-dimensional potential distribution can be recovered. In the start regime (1 T, 1 MA), the beam energy will be below 300 keV, and in the standard regime (2 T, 2 MA), the beam energy will amount to 1000 keV.
Observations of filaments at the TUMAN-3M tokamak
Authors: Yashin A Yu , Askinazi L G , Belokurov A A , Bulanin V V , Zhubr N A , Krikunov S V , Kornev V A , Lebedev S V , Petrov A V , Tukachinsky A S
Published: November 2019

Some factors limiting an increase in the plasma pressure at the periphery of the tokamak plasmas can arise when the improved confinement is achieved in the H-mode. It happens when the edge localized modes (ELMs) develop in tokamak plasmas, and the factors mentioned above manifested themselves in the form of quasi-periodic filamentary structures, or filaments. The formation of such structures results in the occurrence of the anomalous energy and particle flows onto the first wall and divertor plates of tokamaks. Studies of the filaments were previously performed at tokamaks with divertor configuration using various plasma diagnostic methods, including the Doppler backscattering method. The paper presents the first observations of the filaments at the TUMAN-3M, which is the tokamak with limiter configuration. The filaments were studied using the Doppler backscattering method. Plasma was probed by the double-frequency microwave radiation of the O-wave in the frequency range of 27–37 GHz. The data were obtained in the H-mode regime initiated by the pulsed gas injection, in which the ELM-like events are observed. The poloidal velocity of the filaments and their radial localization were determined, and the radial and poloidal sizes of the filaments were also estimated.
High-performance version of the RPB code based on graphic processors for determination of the plasma boundary in tokamaks
Authors: Zotov I V , Vysotsky L I
Published: November 2019

The operation of modern tokamaks is impossible without an effective system for controlling the plasma boundary during the discharge. In this paper, we consider a method for determining the plasma boundary on the basis of integral equations. A high-speed parallel code using GPUs was developed for this purpose. Different methods of parallelization of the algorithm have been considered. The possibility of processing the magnetic measurements in real time during experiments is shown. The effect of the technical parameters of GPUs (the number of cores, the data bus width, the amount of internal memory) on the performance is also shown. The simulation results for the T-15MD tokamak, currently under construction at National Research Center Kurchatov Institute, are presented.
Study of the stochastic clustering on the refractory material surface under the effect of plasma load in the PLM device
Authors: Budaev V P , Fedorovich S D , Martynenko Yu V , Karpov A V , Gerasimov D N , van Oost G , Lukashevsky M V , Lazukin A V , Gubkin M K , Sliva A P , Shestakov E A , Sviridov E V , Marchenkov A I , Voinkova I V , Rogozin K A , Gvozdevskaya D S , Zakletskii Z A
Published: November 2019

Tungsten plates were tested in stationary helium discharges in the PLM device. The duration of discharges in the PLM reached 200 minutes. A distinctive feature of this device is the stationary plasma confinement, which is advantageous for testing fusion materials, including materials of the divertor and first wall of a fusion reactor. During plasma irradiation in the PLM, the thermal load on the surface of the tested plates was more than 1 MW/m2. The temperature of the tested plates amounted to 1000°C and more. Stochastic nanostructures with dimensions of the structural elements of less than 50 nm, including fuzz-type structures, were observed on the processed surfaces of the samples.
Formation and time development of spark channel in strong magnetic field
Authors: Omarov O A , Omarova N O , Omarova P K
Published: November 2019

The characteristics of the spark channel plasma formed in the external longitudinal magnetic field are studied experimentally. In experiment, the current-voltage, optical, and spectral characteristics of the discharge were measured and analyzed. Synchronization of the pulsed electric and magnetic fields was performed. The effect of the magnetic field on the radial expansion of the spark channel, the shock wave formation, as well as the changes in the balance of energy and temperature in the ionized plasma of the high-pressure gas discharge were analyzed. It was found out that, in the strong longitudinal magnetic field, the temperatures of electrons and ions in the spark channel (ne
∼ 1018 cm−3) become equal. The current density, the plasma channel conductivity of the spark channel, and the specific energy deposition into the discharge increased. The channel plasma parameters were analyzed as functions of the external magnetic field.
Creation of dust structures and clusters in a glow discharge in a strong magnetic field
Authors: Karasev V Yu , Dzlieva E S , Pavlov S I , Novikov L A , Tarasov S A
Published: November 2019

During the last 5 years, the range of magnetic field applied in the studies of dusty plasmas extended to the strong field. In particular, it became possible to generate dusty plasma in a glow discharge in a standing striation in a field of 1 T. Features of the formation of dusty plasma in a strong magnetic field, such as its geometric shape, the size of the dust structure and its stability are discussed in this report. Additionaly, the dust component is used for the diagnosis of the glow discharge, because it reflects the geometric size of the dust trap. Experiments showed the tendency of the generated dust clouds to compress in the direction perpendicular to the magnetic field and lengthen along the magnetic field.
Methods for measuring parameters of ultra-wideband microwave radiation
Authors: Dias Mikhaylova D E , Ivanov I E , Strelkov P S , Shumeyko D V , Tarakanov V P
Published: November 2019

The plasma source of ultra-wideband (UWB) microwave radiation was developed. Operation of this source is based on amplification of the relativistic electron beam (REB) noise. The middle frequency of UWB amplifiers of this type is determined only by the plasma density and does not depend on duration of the high-voltage pulse at the cathode. This allows obtaining rather long signals with durations of about 200–300 ns and tuning the signal middle frequency from 2.2 to 3.8 GHz by means of varying the plasma density. A number of problems were solved, which occur in the course of measuring the UWB microwave signal parameters. In particular, a new method for measuring signal energy was developed, the optimal length of the receiving antenna used for recording the UWB radiation spectra was chosen, and the effective potential of the plasma UWB source was estimated. It was demonstrated that the energy of microwave signal is more than 10 J. The effective potential of the plasma UWB source was found to be approximately 400 kV for the signal with a middle frequency of 3 GHz that is comparable to that of other UWB microwave sources. It was also shown that the spectrum of the plasma UWB source is determined by its amplification band and by the oscillation spectrum of the current generated by the explosive emission cathode.
Analysis of optical spectra of microplasma discharges initiated by plasma flow on the surface of the grade 45 carbon steel sample
Authors: Ivanov V A , Letunov A A , Konyzhev M E , Kamolova T I , Dorofeyuk A A
Published: November 2019

The results are presented from studies of the optical emission spectra of the microplasma discharge. The discharge is initiated by the pulsed plasma flow on the sample surface made from the grade 45 carbon structural steel. The discharge was initiated at a voltage of 400 V applied to the sample and maintained by a pulsed current with an amplitude of ∼600 A and duration of 20 ms. The discharge plasma electron temperature was calculated using data on the relative intensities of the iron atom lines. Based on the recorded continuous spectra in the optical spectral range, the melt temperature and the state of aggregation of matter were estimated at the points of microplasma discharge localizaton on the sample surface. It was found that the melt temperature on the steel surface determined using data on the continuous spectrum is approximately 5000 K, while the electron temperature calculated using data on the line spectra of atoms is approximately ∼7400 K.
Microwave injector of plasma formed in a narrow coaxial resonator: experiment and computer simulations
Authors: Balmashnov A A , Butko N B , Kalashnikov A V , Stepina S P , Umnov A M
Published: November 2019

Under the conditions of simultaneous extraction of the ion and electron plasma components and the formation of a current-compensated plasma flow created in a narrow coaxial resonator by the ECR radiation, the radial distributions of the ion current at different mass flow rates of the working gas (argon) were obtained. The computer PIC simulations were performed using the three-dimensional numerical model in order to determine the intensity of the plasma flow as a function of the experimental parameters.
Ignition and combustion stabilization of multicomponent supersonic chemically active flows in low-temperature plasma conditions
Authors: Shibkov V. M
Published: November 2019

An electrodeless freely localized microwave discharge, a surface microwave discharge, a non-equilibrium non-stationary transverse-longitudinal pulsating discharge were used for ignition and combustion stabilization. The induction periods for various discharges and the possibilities of their application for supersonic combustion stabilization inside the direct-flow aerodynamic channels are experimentally determined. A comparison of experimental results with the data of mathematical modeling is presented.
Influence of the sign and magnitude of a surface charge on the breakdown voltage of a barrier corona discharge in Ar
Authors: Akishev Yu S , Balakirev A A , Medvedev M A , Petryakov A V , Trushkin N I
Published: November 2019

The topic of this article is related to the breakdown phenomena in the surface dielectric barrier discharge (SDBD). The surface charge, locally deposited on the dielectric barrier, changes markedly the configuration and intensity of the electric field both on the barrier and in the gas gap. In turn, a change in the local electric field affects the rate of ionization multiplication of electrons in this area and, accordingly, influences the breakdown conditions of both volume and surface barrier discharges. In the case of sinusoidal SDBD, the first breakdown in each next half-cycle will be controlled by the charge deposited on the barrier during the previous half-cycle. Contrariwise, if there are several successive breakdowns in the half-cycle, each next breakdown after the first one will be controlled predominantly by the charge and plasma created by the previous breakdown in this half-cycle but not only by the charge deposited in the previous half-cycle. These features of the SDBD breakdown were investigated by the example of the barrier corona in argon at atmospheric pressure in the pinto-plane configuration. This discharge allows us the controlling of the location of the deposited charge. Surface charge was deposited in advance and by the SDBD itself.
Buoyancy driven convection instability and related pulsing of continuous optical discharges
Authors: Yu Lavrentyev S , Solovyov N G , Shemyakin A N , Yu Yakimov M
Published: November 2019

Optical discharges find now ever expanding applications in science, engineering and medicine. In present study authors discuss the phenomenon of periodic pulsing of a continuous optical discharge (COD) on the base of original experimental results. In the literature there is no general agreement regarding the origin of the considered instability. Authors have obtained the dependence of oscillation frequency on the gas pressure and proposed semi-empirical relations to estimate pulse frequency pressure dependence observed. Regular self-sustained oscillations of COD plasma were explained by the pulsations of heated gas bubble surrounding COD followed by buoyancy driven vortex formation that was detected on schlieren images of convection zone. This kind of buoyant convection instability was determined to obey the same similarity law as cycling frequency of puffing or flickering in diffusion and premixed flames. The instability discussed can affect the performance of COD in some important applications such as high brightness broadband light sources, for instance.
Temperature distribution in the zone of graphite destruction by a nitrogen plasma jet
Authors: Kavyrshin D.I , Korshunov O.V , Sargsyan M.A , Chinnov V.F , Scherbakov V.V
Published: November 2019

Using the automated system of high-speed visualization and spatial-temporal spectral diagnostics, the destructive effect of an atmospheric pressured nitrogen plasma jet with a temperature of 0.7 - 1.0 eV on samples of isotropic and anisotropic graphite was studied. Measurements of the electron, vibrational, and rotational temperatures of the plasma in the zone of destructive interaction were performed, and the pattern of the spatial-temporal distribution of the products of graphite destruction (carbon atoms and cyanogen molecules) was revealed. The efficiency of local spectral analysis of near-surface plasma is shown using a combination of longitudinal and transverse periodic scanning of the emission spectra and recording of instantaneous 2D spectra of the selected spectral region containing the CN and N2
+ bands. The spectral estimate of the concentration of the graphite destruction main product (carbon atoms) is in quantitative agreement with the results of measuring the mass loss rate of the sample material, made by two-positioned visualization of its surface. In the zone of realizable heat loads of 0.5-1.5 kW/cm2, heating of the graphite surface to temperatures of 2800 ÷ 3600 K was achieved and the rate of loss of its material was 3-15 mg/cm2s, which is consistent with the literature data.
The operating mode of the water-cooled MHD accelerator of SMGDU with a magnetic field that changed along the channel
Authors: Baranov D S , Bityurin V A , Bocharov A N , Bychkov S S , Grushin V A , Kusmartseva E V , Tretyakova N V , Batura N I , Zhurkin N G , Kolushov N M
Published: November 2019

The work is aimed at solving the problem of creating in laboratory conditions hypersonic high-enthalpy gas flows that parameters are kept constant for 5-10 seconds. For this purpose the test section of the MHD channel with water-cooled electrodes and side walls was under investigation at the set up with a magnetohydrodynamic accelerator in TsAGI. A new series of runs was performed in which the MHD-acceleration stage was successively increased to 5 seconds. It was determined that the electrical and gas-dynamic characteristics of the MHD accelerator did not depend on the duration of the run. It was first demonstrated that the use of a magnetic field special shaped along the axis of the channel made it possible to avoid catastrophic damage to the side walls of the channel at the entrance and exit of the MHD accelerator, which increased the service life of the installation.
Magnetosphere response to stationary solar wind forcing at various plasma resistivities in 2D MHD simulation
Authors: Gubanov E V , Likhachev A P , Medin S A
Published: November 2019

The magnetosphere response to the stationary solar wind forcing at various values of the plasma resistivity is studied. The simulation is performed within two-dimensional (2D) MHD resistive model; the meridional plane is considered. The solar wind and southward interplanetary magnetic field (IMF) are supposed to be stationary. The calculations were carried out for two plasma resistivity valuesηp= {106; 104} Ω·m, assumed constant in the whole flow field. At higher plasma resistivity the steady magnetosphere convection (SMC) takes place; the solution is symmetric relative to thex-axis. At lower resistivity the sawtooth event is realized; the solution is quasi-periodic and asymmetric. The asymmetry is connected with the formation of the vortex street of Karman type. The sequence of phases of the sawtooth cycle, as well as the evolution of magnetic lines of force and the flow structure in each phase is analyzed. In both solutions the day side magnetic reconnection occurs through the two x-points disposed symmetrically at the top and bottom peaks of the magnetic island.
Erosion of the sputtered electrodes in the surface barrier discharge
Authors: Selivonin I , Lazukin A , Moralev I , Krivov S , Roslyakov I
Published: November 2019

The paper is devoted to a phenomenological study of the modification of sputtered electrodes in a surface dielectric barrier discharge in atmospheric air. A decrease in the power supplied to the discharge in the case of using platinum and aluminum electrodes and an increase in the case of using a copper electrode were demonstrated. It is shown that during long-term operation of the electrode system, a decrease in its cold capacitance is observed. These effects are assumed to be due to the degradation of the electrode material, transfer of erosion products to the surface of the dielectric, as well as morphological changes at the electrode edge.
Classification of vector lines and fields by geometric and numerical methods
Authors: Burakhanov B.M
Published: November 2019

Geometric and numerical methods of classification of vector lines and vector fields are proposed. The division of vector lines of arbitrary vector fields into potential and spiral lines is carried out. The division of vortex vector fields into layered and spiral vector fields is carried out.

It is shown that any vector field can be represented as a superposition of layered vector fields.

Conditions of existence of so-called forceless spiral vector fields are established.

The mathematical conditions to be satisfied by the magnetic fields of magnetic clouds of the solar wind are formulated.
Influence on separation point position by rapid local gas heating with spark discharge on the surface of airfoil streamlined by supersonic airflow
Authors: Saveliev A S
Published: November 2019

Experimental investigation of interaction between gas-dynamic perturbations caused by long spark discharge and separation region on the surface of an aerodynamic model, streamlined by supersonic airflow with Mach number M=2, is presented in this paper. A NACA-airfoil with a relative thickness of 12% of the chord length was used as aerodynamic model. With the help of the Particle Image Velocimetry method airflow was visualized at various angles of attack, delays 0–100 μs relative to the moment of discharge initiation and at various values of stored electric energy 0.1–10 J, that was spent for discharge creation. It was found that the flow disturbance caused by the discharge leads to a short-term displacement of separation point downstream.
How the three Gorges Dam affects the hydrological cycle in the mid-lower Yangtze River: a perspective based on decadal water temperature changes
Authors: Xiong Yu Jiu , Yin Jing , Paw U Kyaw Tha , Zhao Shao Hua , Qiu Guo Yu , Liu Zhiyong
Published: November 2019

Three Gorges Dam (TGD), the world’s largest hydroelectric project in terms of installed capacity, alters the discharge and thermal regime of the Yangtze River in China, thereby threatening the aquatic biodiversity along the mid-lower Yangtze River. Thus, the influence of the TGD impoundment on the river temperature (T
w) and water cycle warrants in-depth examination. To the best of our knowledge, this study is the first to use decadal (2001–2013) Moderate Resolution Imaging Spectroradiometer temperature data to assess the impacts of TGD impoundment on the inland water cycle. We found that (1) spatially, the multiyear T
w decreased by 5 °C along the mid-lower Yangtze River, (2) temporally, T
w exhibited a warming trend after the operation of the TGD began, with most warming occurring from October to December directly after the TGD impoundment, and (3) the correlations between discharge and T
w in the pre- and post-TGD periods have changed; specifically, the closer to the TGD a location is, the greater the change in the relationship. Our analysis implies that downstream water temperature alteration is mainly attributed to the TGD management regime, and the influence is obvious along the 260 km river downstream of the TGD. It is likely that the impoundment of the TGD has increased the water residence time and slowed the water speed downstream.
Does exposure to inflammatory particles modify the pattern of anion in exhaled breath condensate?
Authors: Sauvain J-J , Edmé J-L , Wild P , Suarez G , Bezerra O M P A , Talvani A , Algranti E , Carneiro A P S , Chérot-Kornobis N , Sobaszek A , Hulo S
Published: November 2019

Exposure to environmental and occupational particulate matter (PM) induces health effects on the cardio-pulmonary system. In addition, associations between exposure to PM and metabolic syndromes like diabetes mellitus or obesity are now emerging in the literature. Collection of exhaled breath condensate (EBC) is an appealing non-invasive technique to sample pulmonary fluids. This hypothesis-generating study aims to (1) validate an ion chromatography method allowing the robust determination of different metabolism-related molecules (lactate, formate, acetate, propionate, butyrate, pyruvate, nitrite, nitrate) in EBC; (2) apply this method to EBC samples collected from workers exposed to quartz (a known inflammatory particle), to soapstone (a less inflammatory particle than quartz), as well as to controls. A multi-compound standard solution was used to determine the linearity range, detection limit, repeatability and bias from spiked EBC. The biological samples were injected without further treatment into an ion chromatograph with a conductivity detector. RTube® were used for field collection of EBC from 11 controls, 55 workers exposed to soapstone and 12 volunteers exposed to quartz dust. The analytical method used proved to be adequate for quantifying eight anions in EBC samples. Its sub-micromolar detection limits and repeatability, combined with a very simple sample preparation, allowed an easy and fast quantification of different glycolysis or nitrosative stress metabolites. Using multivariate discriminant analysis to maximize differences between groups, we observed a different pattern of anions with a higher formate/acetate ratio in the EBC samples for quartz exposed workers compared to the two other groups. We hypothesize that a modification of the metabolic signature could be induced by exposure to inflammatory particles like quartz and might be observed in the EBC via a change in the formate/acetate ratio.
The quantitative research and application of the fault lateral sealing ability of structural traps in Weixinan Sag
Authors: Chen Kui , Zhou Jiaxiong , Yang Xibing , Gan Jun , Hu Lin , Wang Zhenzhen , Li Anqi , Li Ming
Published: November 2019

The Weixinan sag in Beibuwan basin experienced strong tectonic movement during late Oligocene, which formed a number of fault-block and fault-nose structural traps. The fault sealing ability, especially the fault lateral sealing ability, plays an important role in the process of structural trap accumulation. The fault lateral sealing ability mainly depends on the AFPD between the material in the fault zone and the target plate. This paper considers the contribution of two fault plates to the muddy content of the fault zone and quotes the geological model of Rm, which can quantitatively evaluate the fault sealing ability. Through analysing the shale content (Rm) and mudstone smear factor (SSF) of the drilled wells of the Member 3 of Weizhou formation in A oilfield, the quantitative chart of Rm-SSF is established. A quantitative prediction technology of the fault sealing oil column height is established by using the principle of the equilibrium between the appearance of fault press difference (AFPD) and the parallel stratigraphic phase of the resultant force. This paper applies the quantitative analysis technology of the fault lateral sealing ability to the A oil field in the WeiXinan sag, and solves the problem why the oil-water interface of each fault block is inconsistent in the A oil field.