General consequences of the violated Feynman scaling

The problem of scaling of the hadronic production cross sections represents an outstanding question in high energy physics especially for interpretation of cosmic ray data. A comprehensive analysis of the accelerator data leads to the conclusion of the existence of breaked Feynman scaling. It was proposed that the Lorentz invariant inclusive cross sections for secondaries of a given type approaches constant in respect to a breaked scaling variable x sub s. Thus, the differential cross sections measured in accelerator energy can be extrapolated to higher cosmic ray energies. This assumption leads to some important consequences. The distribution of secondary multiplicity that follows from the violated Feynman scaling using a similar method of Koba et al is discussed

Inversionless light amplification and optical switching controlled by state-dependent alignment of molecules

We propose a method to achieve amplification without population inversion by anisotropic molecules whose orientation by an external electric field is state-dependent. It is based on decoupling of the lower-state molecules from the resonant light while the excited ones remain emitting. The suitable class of molecules is discussed, the equation for the gain factor is derived, and the magnitude of the inversionless amplification is estimated for the typical experimental conditions. Such switching of the sample from absorbing to amplifying via transparent state is shown to be possible both with the aid of dc and ac control electric fields.Comment: AMS-LaTeX v1.2, 4 pages with 4 figure

Leadership potential of professional teacher associations in Russia: Formation of middle leaders

This research study is aimed at investigating distributed leadership practices in the Russian school system, of which professional teacher associations (PTA) constitute a distinct feature. In particular, we set out to investigate the PTA leadership potential, as well as the role and specific personal characteristics of middle leaders in the Russian school education system. These associations are formed by the school administration on the basis of subject areas, bringing together teachers of maths, history, etc. Teachers join PTAs on a voluntarily basis. The key function of such organisations consists in the implementation of innovative educational approaches and techniques. In order to analyse their leadership potential, we carried out a sociological survey among the employees of high-profile secondary schools (gymnasiums and lyceums) situated in the major Russian city of Ekaterinburg. The research methodology comprised structured interviews with 110 respondents, along with in-depth interviews with 2 school directors, 4 school deputy directors and 6 heads of professional teacher associations. Our results show that the fundamentals and principles of distributed leadership are actively implemented in Ekaterinburg schools. The school administrations encourage the creation of professional teacher associations grouped around subject areas, delegating to these structural units the functions of improving the quality of teaching the respective subjects and disseminating educational innovations, at the same time as fulfilling the requirements of the state and regional education authorities. Such associations are headed by middle leaders, who are nominated by their colleagues and whose candidacy is approved by school seniors, taking into account their professional achievements, experience of leading pedagogical innovations and the presence of the right personal qualities necessary for productive collaborative work. These people perform the role of mediators, operating at the interface between various levels within the school. Although viewed as a school’s personnel reserve for the positions of principals and head teachers, our respondents consider themselves to be ‘more teachers’ or ‘innovators in education’ than administrators. The development of the leadership qualities of such professionals in the Russian school system is shown to be hindered by a ‘glass ceiling’ – a certain limit in their career growth. This discouraging factor results in some middle school leaders searching for professional self-realization opportunities outside the school system, in the spheres of business, science or culture that are believed to provide more opportunities for self-advancement. © 2019 National Research University Higher School of Economics. All rights reserved

Digital fears experienced by young people in the age of technoscience

With the advance of technoscience, digital technologies have started to reshape the traditional array of social fears experienced by younger generations by triggering the appearance of new, digital fears. In this article, we undertake a sociological analysis to investigate the concept of digital fears both theoretically and empirically. Our survey conducted among Russian young people aged 18-30 in 2020 (N = 1050, Sverdlovsk region, Russian Federation) showed that fear is a distinctive characteristic of the social well-being of this generation. Moreover, fear tends to become more pronounced both quantitatively (i.e., the frequency of emergence) and qualitatively (i.e. the emergence of new types). The identified digital fears of young people allowed us to draw their typology. Depending on the specifics of digital threat, the following types were distinguished: those associated with impact and control, crime and security, communication and activity, technology and innovation, and social inequality. We show that the expanding range of social fears leads to the formation of catastrophic thinking in young people, thereby affecting the level of social well-being and distorting the image of the future

Effect of transient pinning on stability of drops sitting on an inclined plane

We report on new instabilities of the quasi-static equilibrium of water drops pinned by a hydrophobic inclined substrate. The contact line of a statically pinned drop exhibits three transitions of partial depinning: depinning of the advancing and receding parts of the contact line and depinning of the entire contact line leading to the drop's translational motion. We find a region of parameters where the classical Macdougall-Ockrent-Frenkel approach fails to estimate the critical volume of the statically pinned inclined drop

МОДЕЛЮВАННЯ ОПТИМАЛЬНОЇ СТРУКТУРИ АКТИВІВ ПІДПРИЄМСТВ М’ЯСОПЕРЕРОБНОЇ ПРОМИСЛОВОСТІ

In today’s economic conditions, problems of functioning of domestic enterprises are not limited by lack of sources of financing of assets, but also often associated with inefficient investment in specific components of property, which adversely affects the level of economic efficiency of Ukrainian enterprises and the development of the economy as a whole. An important factor in making sound, rational and sound decisions about asset management is to improve existing or develop fundamentally new methods and models for optimizing the structure of assets of Ukrainian enterprises using criteria that are most relevant to current economic requirements, environmental challenges and internal objectives. In view of the above, the article demonstrates a clear dependence of the structure of the assets of the enterprise and the key indicators that characterize the effectiveness of its management. The optimal structure of assets for the studied enterprises and possible ways of their achievement are offered taking into account the defined criteria. A comparative assessment of the assets structure of the surveyed enterprises before and after optimization was carried out and on this basis the latter was confirmed by comparing the key parameters of the enterprise performance — profit and market value. A clear sequence of stages of the asset structure optimization model is proposed and described, along with methodological aspects of determining the effective structure of assets, the feasibility of its practical application at Ukrainian enterprises is proved through the achievement of the key goal of the enterprise activity — maximization of market value and profit.У сучасних умовах господарювання проблеми функціонування вітчизняних підприємств не обмежуються браком джерел фінансування активів, але часто пов’язані з неефективним вкладенням коштів у конкретні складові майна, що негативно позначається на рівні ефективності господарювання підприємств України та розвитку економіки в цілому. Вагомим чинником ухвалення зважених, раціональних та обґрунтованих рішень щодо управління активами є удосконалення наявних або розроблення принципово нових методів і моделей оптимізації структури активів підприємств України з використанням критеріїв, які найбільше відповідають сучасним економічним вимогам, викликам зовнішнього середовища та внутрішнім цільовим орієнтирам діяльності підприємства. Зважаючи на вищезазначене, продемонстровано чітку залежність структури активів підприємства і ключових показників, що характеризують ефективність його господарювання. Запропоновано оптимальну з урахуванням визначених критеріїв структуру активів для досліджуваних підприємств та можливі способи їх досягнення. Проведено порівняльну оцінку структури активів досліджуваних підприємств до і після оптимізації та на цій основі підтверджено ефективність останньої шляхом порівняння ключових параметрів ефективності діяльності підприємства — прибутку та ринкової вартості. Запропоновано та описано послідовність етапів моделі оптимізації структури активів із зазначенням методичних аспектів визначення оптимальної структури активів, доведено доцільність її практичного застосування на підприємствах України через досягнення ключової цілі діяльності підприємства — збільшення ринкової вартості та прибутку

Folded modes in the infrared spectra of the spin-Peierls phase of CuGeO_3

Polarized far-infrared transmittance spectra of CuGeO_3 single crystals were measured at different temperatures (6K < T < 300K). Two spectral lines, at 284.2 cm-1 in E||c polarization and at 311.7 cm-1 in E||b polarization, appear at the temperature of the spin-Peierls transition and grow in intensity with decreasing temperature. Both of them are, most probably, folded modes of the dimerized lattice. We discuss a possible role of the spin-phonon interaction in the formation of the 311.7 cm-1 feature.Comment: 4 pages, 5 figures, 1 table; Submitted to Phys.Rev.B Second revision. Figures and text were slightly change

Characteristic length for pinning force density in Nb3SnNb{_3}Sn

The pinning force density $F{_p}(J{_c},B)=J{_c} \times B$ (where $J_c$ is the critical current density, $B$ is applied magnetic field) is one of main quantities which characterizes the resilience of a superconductor to carry dissipative-free transport current in applied magnetic field. Kramer (1973 J. Appl. Phys. 44 1360) and Dew-Hughes (1974 Phil. Mag. 30 293) proposed a widely used scaling law for the pinning force density amplitude: $F{_p}(B)=F{_{p,max}}((p+q){^{(p+q)}}/({p^p}{q^q}))(B/B_{c2}){^p}(1-B/B{_{c2}})^q$, where $F{_{p,max}}$, $B{_{c2}}$, $p$, and $q$ are free-fitting parameters. Since late 1970-s till now, several research groups reported experimental data for the dependence of $F_{p,max}$ on the average grain size, $d$, in $Nb{_3}Sn$-based conductors. Godeke (2006 Supercond. Sci. Techn. 19 R68) proposed that the dependence obeys the law $|F{_{p,max}}(d)|=A \times log(1/d)+B$. However, this scaling law has several problems, for instance, the logarithm is taken from a non-dimensionless variable, and $|F{_{p,max}}(d)|< 0$ for large grain sizes and $|F{_{p,max}}(d)|\rightarrow \infty$ for $d \rightarrow 0$. Here we reanalysed full inventory of publicly available $|F{_{p,max}}(d)|$ data for $Nb{_3}Sn$ conductors and found that the dependence can be described by $F_{p,max}(d)= F_{p,max}(0)exp(-d/{\delta})$ law, where the characteristic length, ${\delta}$, is varying within a remarkably narrow range, i.e. ${\delta}=(175 \pm 13) nm$, for samples fabricated by different technologies. The interpretation of the result is based on an idea that the in-field supercurrent is flowing within a thin surface layer (the thickness of ${\delta}$) near the grain boundary surfaces. Alternative interpretation is that ${\delta}$ represents characteristic length for the exponentially decay flux pinning potential from dominant defects in $Nb{_3}Sn$ superconductors, which are grain boundaries.Comment: 22 pages, 8 figure

Positive Semidefiniteness and Positive Definiteness of a Linear Parametric Interval Matrix

We consider a symmetric matrix, the entries of which depend linearly on some parameters. The domains of the parameters are compact real intervals. We investigate the problem of checking whether for each (or some) setting of the parameters, the matrix is positive definite (or positive semidefinite). We state a characterization in the form of equivalent conditions, and also propose some computationally cheap sufficient\,/\,necessary conditions. Our results extend the classical results on positive (semi-)definiteness of interval matrices. They may be useful for checking convexity or non-convexity in global optimization methods based on branch and bound framework and using interval techniques