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We present a kinetic stability analysis of the solar wind electron distribution function consisting of the Maxwellian core and the magnetic-field aligned strahl, a superthermal electron beam propagating away from the sun. We use an electron strahl distribution function obtained as a solution of a weakly collisional drift-kinetic equation, representative of a strahl affected by Coulomb collisions but unadulterated by possible broadening from turbulence. This distribution function is essentially non-Maxwellian and varies with the heliospheric distance. The stability analysis is performed with the Vlasov–Maxwell linear solver leopard. We find that depending on the heliospheric distance, the core-strahl electron distribution becomes unstable with respect to sunward-propagating kinetic-Alfvén, magnetosonic, and whistler modes, in a broad range of propagation angles. The wavenumbers of the unstable modes are close to the ion inertial scales, and the radial distances at which the instabilities first appear are on the order of 1 au. However, we have not detected any instabilities driven by resonant wave interactions with the superthermal strahl electrons. Instead, the observed instabilities are triggered by a relative drift between the electron and ion cores necessary to maintain zero electric current in the solar wind frame (ion frame). Contrary to strahl distributions modelled by shifted Maxwellians, the electron strahl obtained as a solution of the kinetic equation is stable. Our results are consistent with the previous studies based on a more restricted solution for the electron strahl. [ABSTRACT FROM AUTHOR]

Starch gel electrophoresis was used to study polymorphism of hordeins encoded by the Hrd A and Hrd B loci in 34 local varieties of cultivated barley and 19 accessions of wild barley from Jordan. Thirty-two and 26 alleles for the Hrd A locus were identified in H. vulgare and H. spontaneum, respectively, and 42 and 32 alleles were detected for the Hrd B locus. Allelic frequencies of the Hrd A and Hrd B loci in cultivated barley varied within the range of 0.0029–0.2707 and 0.0029–0.1824, respectively, and within the range of 0.0105–0.1263 and 0.0105–0.0947 in wild barley. Six out of 52 alleles of Hrd A and four out of 70 alleles of Hrd В were common between Jordanian H. spontaneum and H. vulgare. Two of six common alleles of the Hrd A locus found in Jordanian wild and cultivated barley and one common allele of the Hrd В locus were discovered earlier among H. spontaneum accessions from Iran, Turkey, and Syria. However, three common alleles of Hrd A and three common alleles of Hrd В were detected only in Jordanian accessions of wild and cultivated barley. According to archaeological records, the earliest indications of barley utilization in Jordan appeared only in 6700 BC, whereas they were dated in Syria to 9000 BC and in Israel to 17 000 BC. We concluded that Jordan cannot be considered as domestication center of barley. At the same time, Jordanian H. spontaneum could have contributed some alleles of hordein-coding loci to the gene pool of H. vulgare owing to introgression resulting from spontaneous hybridization over the course of crop diffusion from the domestication center outward. [ABSTRACT FROM AUTHOR]

Abstract: Starch gel electrophoresis was performed to study polymorphism of hordeins encoded by the Hrd A and Hrd B loci in 60 local accessions of cultivated barley and 23 accessions of wild barley from Syria. In H. vulgare and H. spontaneum, 37 and 28 alleles, respectively, for the Hrd A locus were identified, and 54 and 38 alleles, respectively, for the Hrd B locus were identified. For H. vulgare, the allelic frequencies ranged from 0.0017 to 0.2250 and from 0.0017 to 0.2182 for the Hrd A and Hrd B loci, respectively. For H. spontaneum, the allelic frequencies for these loci varied from 0.0087 to 0.1391 and from 0.0087 to 0.0696. Only three out of 62 alleles of Hrd A were common between Syrian accessions of H. spontaneum and H. vulgare, while no common alleles were found among 92 alleles of Hrd В. We noted that the hypothesis of barley domestication in Southeastern Turkey/Northern Syria in approximately 9000-8000 BC is based on archaeological findings. However, the earliest records of utilization of barley grains in the Middle East were found in the site Ohalo II near the Sea of Galilee, which was dated back to 17000 BC. The age of wild and cultivated barley grains detected in archaeological findings in Egypt was dated back to 18000 BC. We concluded that Syria cannot be considered as barley domestication center. At the same time, Syrian H. spontaneum could have contributed some alleles of hordein-coding loci to the gene pool of H. vulgare owing to introgression resulting from spontaneous hybridization over the course of crop diffusion from the domestication center outward. [ABSTRACT FROM AUTHOR]

Starch gel electrophoresis is performed to study polymorphism of hordeins encoded by the Hrd A and Hrd B loci in 93 local accessions of cultivated barley and 37 accessions of wild barley from Turkey. Fortyfive and 32 alleles for the Hrd A locus are identified in H. vulgare and H. spontaneum, respectively, and 51 and 49 alleles are identified for the Hrd B locus. For H. vulgare, the allele frequencies range from 0.0011 to 0.2934 for the Hrd A locus and from 0.0011 to 0.0807 for the Hrd B locus. For H. spontaneum, the allele frequencies for these loci vary from 0.0089 to 0.2434 and from 0.0068 to 0.0766, respectively. Three alleles of the Hrd A and two of the Hrd В locus are common for Turkish H. vulgare and H. spontaneum. It was demonstrated that the earliest remains of barley grains were found in archaeological sites in the Middle East in Ohalo II near the Sea of Galilee dated back to the 17th millennium BC. The age of cultivated and wild barley remains from Egyptian archeological sites was determined to be 18000 years. We conclude that the southeast region of Turkey cannot be considered as the domestication center of barley. Herein, H. spontaneum from Southeastern Turkey could have been the donor of some hordein-coding alleles for H. vulgare. This could have been due to spontaneous hybridization events between H. vulgare and H. spontaneum during expansion of cultivated barley. [ABSTRACT FROM AUTHOR]

Starch gel electrophoresis was performed to study the polymorphism of hordeins encoded by the Hrd A, Hrd B, and Hrd F loci in 211 varieties of spring barley. For 41 of these varieties, the genetic formulas were established for the first time. In the two samples of varieties, the comparative analysis of allelic diversity and allele frequencies of hordein-coding loci was carried out. The first sample consisted of 101 spring barley varieties approved for the use on the territory of the Russian Federation in 1999, while the second sample included 160 spring barley varieties that were approved in 2014; 49 of these varieties were common for both samples. It is demonstrated that the current tendency to reduction of the proportion of heterogeneous spring barley varieties is mainly due to the introduction of foreign varieties homogeneous for the hordein-coding loci. At the same time, there is an increase in polymorphism of hordein-coding loci in modern spring barley varieties. The number of alleles for the Hrd A locus increased by five alleles, and for the Hrd B locus, by nine alleles. Along with the alleles recorded earlier in barley landrace populations and varieties bred in 20th century, three novel alleles of the Hrd A locus and four alleles of the Hrd B locus were identified. The number of alleles of the Hrd F locus remained unchanged (four), and the changes in their frequencies were small. At the same time, the changes in frequency observed for some alleles of the Hrd A and Hrd B loci were statistically significant. All newly identified alleles of hordein-coding loci were found with low frequencies (from 0.003 to 0.006), so despite the increased number of alleles, no statistically significant increase in genetic diversity in terms of μ and PIC indices was observed. [ABSTRACT FROM AUTHOR]

We propose a self-similar kinetic theory of thermal conductivity in a magnetized plasma, and discuss its application to the solar wind. We study a collisional kinetic equation in a spatially expanding magnetic flux tube, assuming that the magnetic field strength, the plasma density, and the plasma temperature decline as power laws of distance along the tube. We demonstrate that the electron kinetic equation has a family of scale-invariant solutions for a particular relation among the magnetic-, density-, and temperature-scaling exponents. These solutions describe the heat flux as a function of the temperature Knudsen number γ, which we require to be constant along the flux tube. We observe that self-similarity may be realized in the solar wind; for the Helios data 0.3-1 AU we find that the scaling exponents for density, temperature, and heat flux are close to those dictated by scale invariance. We find steady-state solutions of the self-similar kinetic equation numerically, and show that these solutions accurately reproduce the electron strahl population seen in the solar wind, as well as the measured heat flux. [ABSTRACT FROM AUTHOR]

A variety of studies of magnetised plasma turbulence invoke theories for the advection of a passive scalar by turbulent fluctuations. Examples include modelling the electron density fluctuations in the interstellar medium, understanding the chemical composition of galaxy clusters and the intergalactic medium, and testing the prevailing phenomenological theories of magnetohydrodynamic turbulence. While passive scalar turbulence has been extensively studied in the hydrodynamic case, its counterpart in MHD turbulence is significantly less well understood. Herein we conduct a series of high-resolution direct numerical simulations of incompressible, field-guided, MHD turbulence in order to establish the fundamental properties of passive scalar evolution. We study the scalar anisotropy, establish the scaling relation analogous to Yaglom’s law, and measure the intermittency of the passive scalar statistics. We also assess to what extent the pseudo Alfvén fluctuations in strong MHD turbulence can be modelled as a passive scalar. The results suggest that the dynamics of a passive scalar in MHD turbulence is considerably more complicated than in the hydrodynamic case. [ABSTRACT FROM PUBLISHER]

The nature of subproton scale fluctuations in the solar wind is an open question, partly because two similar types of electromagnetic turbulence can occur: kinetic Alfvén turbulence and whistler turbulence. These two possibilities, however, have one key qualitative difference: whistler turbulence, unlike kinetic Alfvén turbulence, has negligible power in density fluctuations. In this Letter, we present new observational data, as well as analytical and numerical results, to investigate this difference. These results show, for the first time, that the fluctuations well below the proton scale are predominantly kinetic Alfvén turbulence, and, if present at all, the whistler fluctuations make up only a small fraction of the total energy. [ABSTRACT FROM AUTHOR]

This article studies long-period variations in the Earth's upper atmosphere density over several solar activity cycles, using long-term data on the evolution of motion of three artificial satellites (Intercosmos-19, Meteor-1-2, and Cosmos-1154) in orbits at heights of 400-1000 km. The time interval when the satellites were in the orbits covered three solar activity cycles (partly the 21st, completely the 22nd, and partly the 23rd). It is found that the variations in the average density of the upper atmosphere at heights of 400-600 km in the 1980-2000 period were governed by the changes in the solar activity level. [ABSTRACT FROM AUTHOR]

We report the results of our analysis of the variations in the orbit of the CORONAS-F satellite (August 31, 2001–December 6, 2005) during the low-orbit flight stage. We show that extreme solar events and the accompanying phenomena in the near-Earth space and in Earth’s upper atmosphere during the 2004–2005 period (the declining phase of 23rd solar-activity cycle) significantly affected the duration of the “low-orbit” flight stage of the CORONAS-F satellite. [ABSTRACT FROM AUTHOR]

The results of analysis of the trajectory parameters of the orbit of the CORONAS-F spacecraft since its launch (July 2001) and to the present time are reported. Two independent methods are used to compute a prediction for the active lifetime of the satellite in the near-Earth orbit for the period from 2005 through 2006. [ABSTRACT FROM AUTHOR]

We discuss a model for driven supersonic, super-Alfvénic MHD turbulence that is believed to govern the structure of molecular clouds. Such turbulence is highly intermittent; we describe its statistical properties by obtaining scaling of velocity-difference structure functions. This scaling was analytically predicted in Boldyrev (2002), confirmed in numerical simulations by Boldyrev et al. (2002), and discovered in observations by Padoan et al. (2003). [ABSTRACT FROM AUTHOR]

Examines the importance of magnetosonic waves in space and fusion plasmas. Investigation on the propagation of magnetosonic waves in multi-ion-species plasma perpendicular to external magnetic field; Result in the splitting of modes; Comparison between high- and low-frequency waves.

A correction to the article "Nature of Subproton Scale Turbulence in the Solar Wind," that was published on May 31, 2013 issue, is presented.

In this work, we study the process of energy dissipation triggered by a slow large-scale motion of a magnetized conducting fluid. Our consideration is motivated by the problem of heating the solar corona, which is believed to be governed by fast reconnection events set off by the slow motion of magnetic field lines anchored in the photospheric plasma. To elucidate the physics governing the disruption of the imposed laminar motion and the energy transfer to small scales, we propose a simplified model where the large-scale motion of magnetic field lines is prescribed not at the footpoints but rather imposed volumetrically. As a result, the problem can be treated numerically with an efficient, highly accurate spectral method, allowing us to use a resolution and statistical ensemble exceeding those of the previous work. We find that, even though the large-scale deformations are slow, they eventually lead to reconnection events that drive a turbulent state at smaller scales. The small-scale turbulence displays many of the universal features of field-guided magnetohydrodynamic turbulence like a well-developed inertial range spectrum. Based on these observations, we construct a phenomenological model that gives the scalings of the amplitude of the fluctuations and the energy-dissipation rate as functions of the input parameters. We find good agreement between the numerical results and the predictions of the model. [ABSTRACT FROM AUTHOR]

We carry out a population study of magnetized radio filaments in the Galactic centre using MeerKAT data by focusing on the spacing between the filaments that are grouped. The morphology of a sample of 43 groupings containing 174 magnetized radio filaments are presented. Many grouped filaments show harp-like, fragmented cometary tail-like, or loop-like structures in contrast to many straight filaments running mainly perpendicular to the Galactic plane. There are many striking examples of a single filament splitting into two prongs at a junction, suggestive of a flow of plasma along the filaments. Spatial variations in spectral index, brightness, bending, and sharpening along the filaments indicate that they are evolving on a 105−6-yr time-scale. The mean spacings between parallel filaments in a given grouping peaks at ∼16 arcsec. We argue by modeling that the filaments in a grouping all lie on the same plane and that the groupings are isotropically oriented in 3D space. One candidate for the origin of filamentation is interaction with an obstacle, which could be a compact radio source, before a filament splits and bends into multiple filaments. In this picture, the obstacle or sets the length scale of the separation between the filaments. Another possibility is synchrotron cooling instability occurring in cometary tails formed as a result of the interaction of cosmic ray driven Galactic centre outflow with obstacles such as stellar winds. In this picture, the mean spacing and the mean width of the filaments are expected to be a fraction of a parsec, consistent with observed spacing. [ABSTRACT FROM AUTHOR]

Magnetised plasma turbulence pervades the universe and is likely to play an important role in a variety of astrophysical settings. Magnetohydrodynamics (MHD) provides the simplest theoretical framework in which phenomenological models for the turbulent dynamics can be built. Numerical simulations of MHD turbulence are widely used to guide and test the theoretical predictions; however, simulating MHD turbulence and accurately measuring its scaling properties is far from straightforward. Computational power limits the calculations to moderate Reynolds numbers and often simplifying assumptions are made in order that a wider range of scales can be accessed. After describing the theoretical predictions and the numerical approaches that are often employed in studying strong incompressible MHD turbulence, we present the findings of a series of high-resolution direct numerical simulations. We discuss the effects that insufficiencies in the computational approach can have on the solution and its physical interpretation. [ABSTRACT FROM AUTHOR]

The polymorphism of hordeins controlled by the Hrd A, Hrd B, and Hrd F loci in 259 varieties of spring barley approved for use in the Russian Federation was studied by electrophoresis in starch gel. For locus Hrd A, 21 alleles were identified; for locus Hrd B, 34 alleles; and for locus Hrd F, 4 alleles. The allele frequencies of these loci varied in the range of 0.4807–0.0039 (Hrd A), 0.2394–0.0039 (Hrd B), and 0.4633–0.0058 (Hrd F). The polymorphism found at the Hrd loсus theoretically allows differentiating 2856 genotypes. The studied varieties by genotypes of hordein-coding loci were distributed in 113 groups including from 1 to 31 varieties. The largest number of groups (77–68.15%) included one variety. These varieties were unique in terms of Hrd locus genotypes. Another 18 groups (15.94%) included two varieties each with identical electrophoregrams of hordein. Groups including 27 and 31 varieties with the same genetic formulas of hordein were found. The use of additional genetic markers—SSR markers and water-soluble grain proteins for differentiation and identification of barley varieties that are identical in hordeins—is discussed. The results of using electrophoretic analysis of hordein in laboratory varietal control of malting barley from 2005 to 2019 are presented. The trend of increasing lots with high varietal purity (more than 95%) from 27% in 2005 to 62–65% in 2016–2019 is shown. At the same time, over the past 5 years, the share of batches of malting barley that do not correspond to the declared varieties has decreased from 14.7% in 2015 to 4.2–4.6% in 2018 and 2019 respectively. [ABSTRACT FROM AUTHOR]

We present a drift kinetic model for the free expansion of a thermal plasma out of a magnetic nozzle. This problem relates to plasma space propulsion systems, natural environments such as the solar wind, and end losses from the expander region of mirror magnetically confined fusion concepts such as the gas dynamic trap. The model incorporates trapped and passing orbit types encountered in the mirror expander geometry and maps to an upstream thermal distribution. This boundary condition and quasineutrality require the generation of an ambipolar potential drop of ∼ 5 T e / e , forming a thermal barrier for the electrons. The model for the electron and ion velocity distributions and fluid moments is confirmed with data from a fully kinetic simulation. Finally, the model is extended to account for a population of fast sloshing ions arising from neutral beam heating within a magnetic mirror, again resulting in good agreement with a corresponding kinetic simulation. [ABSTRACT FROM AUTHOR]

This article is devoted to the search for a generating function for network delay simulation. We justify the choice of the measurement system used to collect delay data with microsecond accuracy. Experimental data are employed in order to form a hypothesis regarding the exponential type of delay. The paper is restricted to the study of the simplest two cases: the linear and quadratic dependence of the delay distribution function. The application of the Pearson criterion led to the conclusion that an exponential distribution can be used to describe network delay, but is valid only for small periods from 10 to 30 minutes. We also justify the expression for the distribution function and generating function for further theoretical and experimental calculations. [ABSTRACT FROM AUTHOR]

The helioseismological experiment onboard the CORONAS-PHOTON satellite is intended for the study of characteristics and the internal structure of the Sun using the solar eigenmodes spectrum obtained by the measurement of fluctuations of the solar radiation intensity. This experiment is the continuation of investigations of solar global oscillations started onboard artificial satellites CORONAS-I and CORONAS-F. Measurements of fluctuations of the solar radiation intensity in seven optical ranges-from the near ultraviolet to infrared spectral regions-are carried out by the solar photometer SOKOL (SOlnechnye KOLebaniya (Solar Oscillations)) developed at IZMIRAN. Over an instrument operation period of more than 9 months, a large volume of the scientific information (more than 500 MB) has been obtained. The primary processing of obtained data was performed, and spectra of fluctuations of the solar radiation intensity were constructed. On the basis of part of the processed information obtained by the photometer SOKOL, and data of the experiment DIFOS (Differential Oscillations of the Sun) onboard the artificial satellite CORONAS-F, the dependence of the relative amplitude of oscillations on the wavelength of the observation was determined. [ABSTRACT FROM AUTHOR]

A pinch analysis of the AVDU A12/2 crude distillation unit processing 2 million tons of crude oil per year is made. A pinch retrofit of the recuperative heat-exchange system of the unit is performed. It is shown that the implementation of the proposed project will reduce the arbitrary energy consumption by 60%, which corresponds to a reduction in specific fuel consumption from 36 to 13 kg per ton of refined oil. [ABSTRACT FROM AUTHOR]

Abstract-The measurement data obtained onboard the CORONAS-F spacecraft are compared to the parame- ters of the Earth's upper atmosphere calculated by models. Examination of model results and their comparison to the experimental data show that current models of the Earth's atmosphere should be corrected. Possible ways of solving this problem are discussed. [ABSTRACT FROM AUTHOR]

The paper presents a brief review of the instruments developed for measurement of ionizing extreme UV solar radiation at wavelengths of less than 130 nm onboard the CORONAS-I and CORONAS-F satellites and summarizes the observation data. The main goal of the study was to obtain information concerning variations of fluxes of solar radiation and solar flares at various wavelengths in the extreme ultraviolet. SUFR radiometers based on the thermoluminescent method were mounted onboard both CORONAS satellites ( CORONAS-I and CORONAS-F). They performed measurements at λ < 130 nm. Spectral measurements in the 30.4-nm line were made by the photoelectronic spectrometer VUSS tested on CORONAS-I. Spectral measurements in the waveband including the H Lα line (121.6 nm) were conducted by the VUSS-L instrument (a Lyman alpha spectrophotometer) onboard the CORONAS-F satellite. The basic characteristics of the instruments, which were supposed to be used in a system of space weather monitoring on patrol satellites of the hydrometeorological service of Russia, are presented. The main data on the solar radiation flux at λ < 130 nm for minimum and maximum solar activity are given for quiet conditions and during solar flares. [ABSTRACT FROM AUTHOR]

The first scientific results of the analysis of the X-ray spectra of flares and active regions in the solar corona obtained by Polish-led spectrometers RESIK and DIOGENESS onboard the CORONAS-F satellite are presented. The instruments were designed and made in the Solar Physics Division of the Space Research Center of the Polish Academy of Sciences (SRC PAS, Wroclaw, Poland). The Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation (IZMIRAN, Russia) and the Astronomical Institute of the Czech Academy of Sciences also participated in designing the DIOGENESS spectrometer, while IZMIRAN (Russia), Mullard Space Science Laboratory (MSSL, Great Britain), Rutherford Appleton Laboratory (RAL, Great Britain), and Naval Research Laboratory (NRL, United States) contributed to the development of the RESIK spectrometer. In the paper, we give spectra obtained in a number of previously unstudied spectral ranges and a preliminary identification of new spectral lines. The results for the shifts of the X-ray spectral lines observed with the use of a so-called dopplerometer configuration are also presented. Methods for determining the abundances of the rare elements in the solar corona, including chlorine, potassium, and argon, are described. [ABSTRACT FROM AUTHOR]