Hydrodynamical approach to chirality production during axion inflation

We study chirality production in the pseudoscalar inflation model of magnetogenesis taking into account the Schwinger effect and particle collisions in plasma in the relaxation time approximation. We consider the Schwinger production of one Dirac fermion species by an Abelian gauge field in two cases: (i) the fermion carries only the weak charge with respect to the U(1) group and (ii) it is also charged with respect to another strongly coupled gauge group. While the gradient-expansion formalism is employed for the description of the evolution of gauge field, plasma is described by hydrodynamical approach which allows us to determine the number, energy density, and chirality of produced fermions. It is found that while chirality production is very efficient for both, weakly and strongly interacting fermions, the resulting gauge field is typically stronger in the case of strongly interacting fermions due to suppression of the Schwinger conductivity by particle collisions.Comment: 16 pages, 6 figure

Optical tweezers for vortex rings in Bose-Einstein condensates

We study generation and stabilization of vortex rings in atomic Bose-Einstein condensates. We suggest an approach for generating vortex rings by optical tweezers - two blue-detuned optical beams forming a toroidal void in a magnetically or optically conf

Аналіз композиційно-конструктивного устрою одягу для провідників залізничного транспорту України

The article described the current uniforms for railway workers of Ukraine. On the basis of theoretical studies are organized by compositional and structural features varieties of sets of uniforms for men and women for the conductor rail. Found insufficient quality ergonomic, aesthetic and reliability, formulated the task of developing assortment series sets with improved quality.В статье охарактеризована существующая форменная одежда для работников железнодорожного транспорта Украины. На основе теоретических исследований систематизированы согласно композиционно-конструктивным признакам разновидности комплектов форменной мужской и женской одежды для проводников железнодорожного транспорта. Выявлен недостаточный уровень качества эргономических, эстетических и показателей надежности, сформулированы задачи по разработке ассортиментных рядов комплектов с улучшенными показателями качества.В статті надано характеристику існуючого форменого одягу для працівників залізничного транспорту України. На основі теоретичних досліджень систематизовано за композиційно-конструктивними ознаками різновиди комплектів форменого чоловічого та жіночого одягу для провідників залізничного транспорту. Виявлено недостатній рівень якості ергономічних, естетичних та показників надійності, сформульовано завдання щодо розробки асортиментних рядів комплектів з покращеними показниками якості

New IGIP Curriculum for Advanced Training of Engineering University Teachers

The discussion of the new Curriculum for pedagogical training of teachers of technical disciplines, prior to its approval by the IGIP Executive Committee in the fall of 2019 is considered. The previous version of this Curriculum was approved in 2013. Over the past period, there have been significant changes in the use of ICT in training, discussed in the proposals of the National IGIP Offices, in the proceedings of the Annual IGIP Conferences, including the International Conference ICL-IGIP held in Tallinn on 23–25 September, 2020. At this Conference, IGIP President Hanno Hortsch in his presentation has published the IGIP curriculum in the form of a table (now we present it in translation into Russian) and reported about his vision of its use. The authors formulate their point of view on the topic basing on the overview of the presentations given at this Conference and relevant articles published in the latest issues of the journal “Higher education in Russia”

Synthesis of Superhydrophobic Carbon Surface during Combustion Propane

We synthesize and deposit carbon nanostructures through flame synthesis on silicon and nickel wafers at different nonpremixed flame locations to produce hydrophobic surfaces. The hydrophobicity is characterized through the contact angle for water droplets placed on the surface. The surface morphology of the nanoparticles is obtained from SEM images. The morphology and hydrohobicity of the nanostructured surfaces depends upon the deposition, which differs at various flame locations. We determine the optimum flame location for the synthesis and deposition of surface carbon nanostructures that lead to maximum hydrophobicity

Structural, magnetic and magnetoelectric studies of BaTiO3:Co nanocomposite films formed by ion-beam methods

Thin-film samples of ferroelectric barium titanate (BaTiO3) with cobalt nanoparticles were obtained by using either ion implantation or ion beam sputtering deposition (IBSD) techniques. The samples were characterized using X-ray diffraction, transmission electron microscopy, magnetometry and ferromagnetic resonance to investigate the efficiency of above ion-beam methods in the synthesis of magnetoelectric nanocomposite materials. Our structural studies show that high-fluence implantation with Co+ ions results in the formation of cobalt nanoparticles with mean size of 5 nm in thin surface layer of monocrystalline plate of BaTiO3. On the other hand, larger nanoparticles of cobalt with sizes from 5 up to 40 nm are formed in polycrystalline BaTiO3 matrix only after high-temperature annealing of BaTiO3:Co composite film prepared by IBSD method. Both types of thin-film nanocomposite samples have similar magnetic hysteresis curves in the sample plane. However Co-implanted BaTiO3 reveals strong uniaxial magnetic anisotropy for out-of-plane orientation, while BaTiO3:Co nanocomposite film demonstrates almost isotropic magnetic response. Strong magnetoelectric effect are observed in Co-implanted BaTiO3, and no magnetoelectric coupling are detected in BaTiO3:Co nanocomposite film formed by IBSD with subsequent high-temperature annealing. © 2014 Elsevier B.V. All rights reserved

Ion beam synthesis and investigation of nanocomposite multiferroics based on barium titanate with 3d metal nanoparticles

Samples of nanocomposite multiferroics have been synthesized by implantation of Co+, Fe+, and Ni+ ions with an energy of 40 keV into ferroelectric barium titanate plates to doses in the range (0.5-1.5) × 1017 ions/cm2. It has been found that nanoparticles of metallic iron, cobalt, or nickel are formed in the barium titanate layer subjected to ion bombardment. With an increase in the implantation dose, the implanted samples sequentially exhibit superparamagnetic, soft magnetic, and, finally, strong ferromagnetic properties at room temperature. The average sizes of ion-synthesized 3d-metal nanoparticles vary in the range from 5 to 10 nm depending on the implantation dose. Investigation of the orientation dependence of the magnetic hysteresis loops has demonstrated that the samples show a uniaxial ("easy plane") magnetic anisotropy typical of thin granular magnetic films. Ferromagnetic BaTiO3: 3d metal samples are characterized by a significant shift of the ferromagnetic resonance signal in an external electric field, as well as by a large (in magnitude) magnetodielectric effect at room temperature. These results indicate that there is a strong magnetoelectric coupling between the ferroelectric barium titanate matrix and ion-synthesized nanoparticles of magnetic metals. © 2013 Pleiades Publishing, Ltd