Higher radial modes of azimuthal surface waves above the upper-hybrid frequency in cylindrical waveguides partially filled by plasma

Azimuthal surface waves (ASWs) are known to be eigen waves of cylindrical metal waveguides partially filled by magnetoactive plasma. Zeroth radial modes were under study earlier. Their dispersion properties are known to be significantly influenced by the plasma column properties: its particle density, external axial static magnetic field, geometric dimensions, – rather than properties of the dielectric layer which separates the plasma column from the metal wall. Application of higher order ASWs in the low-frequency range was shown earlier to make it possible to get advantage of exciting ASWs with higher frequency than in the case of zeroth order ASWs without no change in the waveguide design. The present study generalises those investigation for the case of the waves above the upper hybrid frequency.Відомо, що азимутальні поверхневі хвилі (АПХ) є власними хвилями циліндричних металевих хвилеводів, які частково заповнені магнітоактивною плазмою. Нульові радіальні моди АПХ вивчені раніше. Відомо, що на їхні дисперсійні властивості більш значною мірою впливають параметри плазмового стовпа: густина його частинок, зовнішнє аксіальне стале магнітне поле, геометричні розміри, – ніж властивості діелектричного шару, який відокремлює плазмовий стовп від металевої стінки. Раніше було показано, що застосування вищих радіальних мод АПХ в низькочастотному діапазоні дає можливість досягти перевагу при збудженні АПХ у вигляді більш високої частоти, ніж у випадку нульової радіальної моди АПХ, без жодних змін у параметрах хвилеводу. Ця робота узагальнює проведені раніше дослідження на випадок хвиль вище верхньої гібридної частоти.Известно, что азимутальные поверхностные волны (АПВ) являются собственными волнами цилиндрических металлических волноводов, частично заполненных магнитоактивной плазмой. Нулевые радиальные моды АПВ изучены ранее. Известно, что на их дисперсионные свойства заметнее влияют параметры плазменного столба: плотность его частиц, внешнее аксиальное постоянное магнитное поле, геометрические размеры, – чем свойства диэлектрического слоя, который отделяет плазменный столб от металлической стенки. Ранее было показано, что применение высших радиальных мод АПВ в низкочастотном диапазоне позволяет достичь преимущества при возбуждении АПВ в виде более высокой частоты, чем в случае нулевой радиальной моды АПВ, без каких-либо изменений в параметрах волновода. Эта работа обобщает проведенные ранее исследования на случай волн выше верхней гибридной частоты

Theory of transverse spin dynamics in a polarized Fermi liquid and an itinerant ferromagnet

The linear equations for transverse spin dynamics in a weakly polarized degenerate Fermi liquid with arbitrary relationship between temperature and polarization are derived from Landau-Silin phenomenological kinetic equation with general form of two-particle collision integral. Unlike the previous treatment where Fermi velocity and density of states have been taken as constants independent of polarization here we made derivation free from this assumption. The obtained equations are applicable for description of spin dynamics in paramagnetic Fermi liquid with finite polarization as well in an itinerant ferromagnet. In both cases transverse spin wave frequency is found to be proportional to the square of the wave vector with complex constant of proportionality (diffusion coefficient) such that the damping has a finite value at T=0. The polarization dependence of the diffusion coefficient is found to be different for a polarized Fermi liquid and for an itinerant ferromagnet. These conclusions are confirmed by derivation of transverse spin wave dispersion law in frame of field theoretical methods from the integral equation for the vortex function. It is shown that similar derivation taking into consideration the divergency of static transverse susceptibility also leads to the same attenuating spin wave spectrum.Comment: 7 pages, no figure

Method of individual forecasting of sow reproductive performance on the basis of a non-linear canonical model of a random sequence

Improvement of sow reproductive performance is a key factor determining the efficiency of the pig production cycle and profitability of pork production. This article presents the solution of an important scientific and practical problem of individual forecasting of sow reproduction . The population used for the present study is from a pig farm managed by the Limited Liability Company (LLC) ‘Tavriys’kisvyni’ located in Skadovsky district (Kherson region, Ukraine). The experimental materials used for this study consisted of 100 inds. of productive parent sows of the Large White breed.The litter size traits – the total number of piglets born (TNB), number of piglets born alive (NBA) and number of weaned piglets (NW) – were monitored in the first eight parities over an eleven year period (2007–2017). The method of the forecasting of sow litter size is developed based on the non-linear canonical model of the random sequence of a litter size change. The proposed method allows us to take maximum account of stochastic peculiarities of sow reproductive performance and does not impose any restrictions on the random sequence of a litter size change (linearity, stationarity, Markov property, monotony, etc.). The block diagram of the algorithm presented in this work reflects the peculiarities of calculation of the parameters of a predictive model. The expression for the calculation of an extrapolation error allows us to estimate the necessary volume of a priori and a posteriori information for achieving the required quality of solving the forecasting problem. The results of the numerical experiment confirmed the high accuracy of the proposed method of forecasting of sow reproduction. The method offered by us almost doubles the accuracy of forecasting of sow litter size compared to the use of the Wiener and Kalman methods. Thus, average forecast error decreases across the range of features TNB (1.71), NBA (1.68) and NW (1.25 piglets). Apparently, this may reflect a higher level of manifestation of the genetically determined level of individual sow fertility at the moment of piglet weaning. The higher adequacy of the developed mathematical model with regard to NW can be also due to the fact that the relations between sow litter size in different farrowings primarily have a non-linear character, which is taken into maximum account in our offered model. Given non-linearity, on the other hand, turns out to be a significant factor determining a lower estimation of the repeatability value for NW compared to the estimations for TNB and NBA. The use of the developed method will help to improve the efficiency of pig farming

Focusing of a tabletop soft-x-ray laser beam and laser ablation

Includes bibliographical references (page 1716).We focused the beam of a high-repetition-rate capillary-discharge tabletop laser operating at a wavelength of 46.9 nm, using a spherical Si/Sc multilayer mirror. The energy densities significantly exceeded the thresholds for the ablation of metals. Single-shot laser ablation patterns were used in combination with ray-tracing computations to characterize the focused beam. The radiation intensity within the 2-μm-diameter central region of the focal spot was estimated to be ≈1011 W/cm2, with a corresponding energy density of ~100 J/cm2

Skin effect with arbitrary specularity in Maxwellian plasma

The problem of skin effect with arbitrary specularity in maxwellian plasma with specular--diffuse boundary conditions is solved. A new analytical method is developed that makes it possible to to obtain a solution up to an arbitrary degree of accuracy. The method is based on the idea of symmetric continuation not only the electric field, but also electron distribution function. The solution is obtained in a form of von Neumann series.Comment: 7 pages, 2 figure

Interaction of the Electromagnetic p-Waves with Thin Metal Films

For the first time it is shown that for thin metallic films thickness of which not exceed thickness of skin-layer, the problem allows analytical solution for arbitrary boundary value problems. The analysis of dependence of coefficients of transmission, reflection and absorbtion on angle incidence, thickness of films and coefficient of specular reflection is carried out.Comment: 15 pages, 9 figure

The influence of working gas pressure on interlayer mixing in magnetron-deposited Mo/Si multilayers

Impact of Ar gas pressure (1−4 mTorr) on the growth of amorphous interlayers in Mo/Si multilayers deposited by magnetron sputtering was investigated by small-angle x-ray scattering (l=0.154 nm) and methods of cross-sectional transmission electron microscopy. Some reduction of thickness of the amorphous inter-layers with Ar pressure increase was found, while composition of the layers was enriched with molybdenum. The interface modification resulted in raise of EUV reflectance of the Mo/Si multilayer

The use of electrotechnical equipment for food production wastewater treatment

The wastewater ecological danger has been established on the example of a meat processing enterprise, systematic exceedances of normative maximum permissible concentrations of contaminants and unpredictable fluctuations of their values have been registered. The design of thesewage treatment electroflotocoagulation module is developed. Wastewaters from a dairy plant, a bakery, a distillery and a sugar plant were treated at the electrotechnical complex. Analytical dependencies are established to determine the energy consumption for counteraction of potential emergencies

THE ZONAL VARIABILITY OF YIELD OF LEAF CUTTING LETTUCE VARIETY SNEZHINKA

Purpose. Determine the dependence of yield of cutting lettuce variety ‘Snezhinka ‘on the hydrothermal coefficients of the Left bank Forest-steppe and Polissya zones, and analyze the parameters of the zone's adaptive of varieties. Methods. Field studies, statistical methods for determining ecological variability. Results. The results of researches on determining the dependence of productivity of cutting variety ‘Snezhinka’ on the hydrothermal coefficient in the zones of the Left bank Forest-steppe and Polissya of Ukraine are presented. The optimum values of the GTK for obtaining the maximum yield in the conditions of the Left bank Forest-steppe make up 0,8–1,0, in the Polissya – 1,2–2,0. In conditions of Polissya, the influence of weather conditions on the yield of cutting lettuce was the lowest, which is confirmed not by high values of the coefficient of elasticity (0,00053–0,00155). Relative stability of variety is greater in the Forest-steppe (20,24 %), that is, in the data of the soil-climatic conditions for the variation of weather conditions, stable high productivity is not guaranteed. But in the conditions of the Forest-steppe on the parameter bi of cutting lettuce variety ‘Snezhinka’ was more plastic (1,24), that is, in favorable weather conditions, showed relatively high yields. In the conditions of Polissya, on the contrary, variety ‘Snezhinka’ was less plastic (0,76) and with a lower level of relative stability of genotype (15,94 %). The breeding value of genotype for the variety of cutting lettuce ‘Snezhinka’ in the zone of Polissya was higher (4,59). Conclusions. In the zone of the Left bank Forest-steppe, according to the fluctuations of the year cultivation of the sum of active temperatures 1076-1318 oC and the amount of precipitation 56,6–193,6 mm, the yield of cutting lettuce ‘Snezhinka’ was 6,7-12,2 t/ha. In the zone of Polissya, the ratio of precipitation to the sum of active temperatures almost did not affect the formation of yields at its fluctuation from 0,65 to 1,48. The dependence of yield formation in the zones of the Forest-steppe and Polissya on the coefficient of elasticity, respectively, was 0,05 and 0,26, indicating the favorable conditions of natural zone of the Left-bank Forest-steppe for the development of seedlings. The general and specific adaptive ability of variety Snezhinka was higher in the Forest-steppe zone (0,75 and 3,93 respectively); The largest breeding value of variety is characteristic for the zone of Polissya (4,59)