215 research outputs found
Induction of Polymerization of the Surface Nanostructures of the Electrodes by Electric Field
The results of experimental studies of the interface of "dielectric liquid - nanostructured metal electrode" after electroconvection is presented. It is discovered the patterns of structuring of areas of polymerization showing disruption of the diffusion layer and the processes of charge injection from the tops of structures.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3636
НОВОЕ НАПРАВЛЕНИЕ НАУЧНЫХ ИССЛЕДОВАНИЙ ПО ИЗУЧЕНИЮ ПРОДУКТИВНОСТИ ЖИВОТНЫХ В СВЯЗИ С РАЗНОЙ КОСМОФИЗИЧЕСКОЙ АКТИВНОСТЬЮ
Brief results of research at the Department of Zootechnics of the PFUR in more than 30 years are reported on the relationship between cosmophysical activity and animal productivity (the rhythm of milk yield of cows and the chemical composition of milk, the biochemical composition of cows' blood). It is established that in even and odd 11-year solar cycles, animals react differently to cosmophysical activity. In even cycles, the increase in solar activity contributes to the growth of milk yields. In odd cycles, increasing solar activity reduces milk yield. The data of scientific observations, covering the periods of even and odd cycles, should be grouped and analyzed separately by cycles. Within 2—3 years, at the lowest peak of solar activity, and 2—3 years — at the top peak of activity (with the change of magnetic poles on the Sun) minimal and unreliable correlations are noted. The strongest correlation was noted in the middle of the rise or decrease in solar activity. The rhythm of milk yield was noted regard-less of the lactation phase of cows. Approximately 1/3 of the time, milk yield increased, 1/3 — decreased and 1/3 — remained at the same level, with fluctuations, with periods from 2.7; 3.3; up to 5.5 days. With an increase in milk yield during 31.0% of lactation days, the content of fat and protein in milk decreased, respectively, 25.8 and 25.4% of the time. With a decrease in milk yield during 33.7% of lactation days, the fat and protein content did not change, respectively, 49.8 and 48.1% days. The most pronounced interval of rhythmicity of the concentration of fat and protein in milk from 2 to 2.5 days with an average value of 2.2 days was established. In addition rhythm 2.8; 3.4; 4.4; 8; 32; 41,1 and 72 days was marked. Approxi-mately with the same cycles in the milk, sugar concentrations, density and acidity were changed.Приведены краткие результаты исследований на кафедре зоотехнии РУДН более чем за 30 лет о взаимосвязи космофизической активности и продуктивности животных (ритмичности удоев коров и химического состава молока, биохимическом составе крови коров). Установлено, что в четные и нечетные 11-летние солнечные циклы животные по-разному реагируют на космофизические про-явления. В четные циклы повышение солнечной активности способствует росту удоев. В нечетные циклы повышение солнечной активности снижает удои. Данные научных наблюдений, охватывающих периоды четных и нечетных циклов, следует группировать и анализировать отдельно по циклам. В течение 2-3 лет на нижнем пике солнечной активности и 2-3 лет - на верхнем пике активности (при смене магнитных полюсов на Солнце) отмечаются минимальные и недостоверные корреляционные связи. Наиболее стабильные связи бывают в середине подъема или снижения солнечной активности. При этом ритмичность удоев отмечалась независимо от фазы лактации коров. Примерно 1/3 времени удои росли, 1/3 - снижались и 1/3 - оставались на одном уровне, при колебаниях суточных удоев с периодами от 2,7; 3,3 до 5,5 суток. При увеличении удоев в течение 31,0% дней лактации содержание жира и белка в молоке уменьшалось соответственно 25,8 и 25,4% времени. При снижении же удоев в течение 33,7% дней лактации содержание жира и белка не изменялось соответственно 49,8 и 48,1% дней. Наиболее выражен интервал ритмичности концентрации жира и белка в молоке от 2 до 2,5 суток со средним значением 2,2 дня; затем отмечается ритм 2,8; 3,4; 4,4; 8; 32; 41,1 и 72 суток. Примерно с такими же циклами в молоке изменялись концентрации сахара, плотности и кислотности
Visualization of metasurface eigenmodes with magnetic resonance imaging
The ability to control the electromagnetic near field with metasurfaces offers potential applications over the frequency range from radio frequency to optical domains. In this work, we show an essential feature of metasurfaces, subwavelength field confinement via excitation of a large number of eigenstates in a narrow frequency range, and demonstrate an innovative way of visualizing profiles of metasurface eigenmodes with the aid of a magnetic resonance imaging (MRI) system. We show that by tuning different eigenmodes of the metasurface to the Larmor frequency, we can passively tailor the near-field distribution to adjust the desired pattern of radio-frequency excitation in a MRI experiment. Our work demonstrates a practical nonperturbed rapid way of imaging metasurface eigenmodes
Recurrent and sporadic Forbush decreases during solar cycles 23–24
A comparison has been made between recurrent (associated with high-speed streams from coronal holes) and sporadic (caused by interplanetary coronal mass ejections (ICMEs)) Forbush decreases (FDs) in solar cycles 23 and 24 (as well as in the maxima of these cycles and the minimum between them). Forbush Effects and Interplanetary Disturbances database created and maintained in IZMIRAN provided a large number of events (about 1700 isolated FDs, among them 350 recurrent FDs, and 207 sporadic FDs selected with high reliability), which allowed us to apply statistical methods. The results revealed that sporadic FDs prevailed in the maxima of the cycles; recurrent FDs, in the minimum between the cycles. FD parameters (magnitude, decrease rate, anisotropy) are larger for sporadic events than for recurrent ones, especially in the maxima of the cycles. FD magnitude is greater in the maxima than in the minimum for sporadic events, and it changes weakly for recurrent ones. The solar wind velocity is on average greater for recurrent events than for sporadic ones; it is larger for recurrent FDs in the minimum and for sporadic FDs in the maxima. The magnetic field is stronger for sporadic FDs than for recurrent ones in the maxima and it is approximately equal for both types of events in the minimum. The magnetic field of ICMEs is weaker in the current solar cycle than in the previous one. The duration of the FD main phase is less in the maxima for both types of events; sporadic FDs developed significantly faster than recurrent ones in the maximum of cycle 23
Magnetic Flux of EUV Arcade and Dimming Regions as a Relevant Parameter for Early Diagnostics of Solar Eruptions - Sources of Non-Recurrent Geomagnetic Storms and Forbush Decreases
This study aims at the early diagnostics of geoeffectiveness of coronal mass
ejections (CMEs) from quantitative parameters of the accompanying EUV dimming
and arcade events. We study events of the 23th solar cycle, in which major
non-recurrent geomagnetic storms (GMS) with Dst <-100 nT are sufficiently
reliably identified with their solar sources in the central part of the disk.
Using the SOHO/EIT 195 A images and MDI magnetograms, we select significant
dimming and arcade areas and calculate summarized unsigned magnetic fluxes in
these regions at the photospheric level. The high relevance of this eruption
parameter is displayed by its pronounced correlation with the Forbush decrease
(FD) magnitude, which, unlike GMSs, does not depend on the sign of the Bz
component but is determined by global characteristics of ICMEs. Correlations
with the same magnetic flux in the solar source region are found for the GMS
intensity (at the first step, without taking into account factors determining
the Bz component near the Earth), as well as for the temporal intervals between
the solar eruptions and the GMS onset and peak times. The larger the magnetic
flux, the stronger the FD and GMS intensities are and the shorter the ICME
transit time is. The revealed correlations indicate that the main quantitative
characteristics of major non-recurrent space weather disturbances are largely
determined by measurable parameters of solar eruptions, in particular, by the
magnetic flux in dimming areas and arcades, and can be tentatively estimated in
advance with a lead time from 1 to 4 days. For GMS intensity, the revealed
dependencies allow one to estimate a possible value, which can be expected if
the Bz component is negative.Comment: 27 pages, 5 figures. Accepted for publication in Solar Physic
H⁻ injector for Moscow meson factory linac
Status report is presented for an H⁻ injector being now under construction. The injector parameters are as follows: energy − 400 keV; average beam current − 400 µA; beam pulse duration − up to 200 µs; pulse repetition rate − 50 Hz. A pulsed high-voltage generator and a surface-plasma ion source power supply have been developed and
manufactured.Представлено состоянии работ по созданию инжектора отрицательных ионов водорода с энергией
400 кВ, который должен обеспечить средний ток пучка ионов до 400 мкА при длительности импульса тока
до 200 мкс и частоте повторения импульсов 50 Гц. Разработаны, изготовлены и смонтированы генератор
ускоряющего импульсного напряжения и система питания поверхностно-плазменного ионного источника.Представлено звіт про стан робіт зі створення інжектора негативних іонів водню з енергією 400 кВ, що
повинен забезпечити середній струм пучка іонів до 400 мкА при тривалості імпульсу струму пучка до
200 мкс і частоті повторення імпульсів 50 Гц. Розроблено, виготовлені і змонтовані генератор
прискорювальної імпульсної напруги і система живлення поверхнево-плазмового іонного джерел
Oscillating Solitons Pinned to a Nonmagnetic Impurity in Layered Antiferromagnets
We argue that an oscillatory motion of impurity-pinned solitons may occur in
layered antiferromagnetic compounds. The characteristic frequencies of these
modes, that may be detected by resonance or inelastic neutron scattering, are
estimated analytically and depend on the soliton sizes and types .Comment: 11 pages, 1 figur
AEGIS at CERN: Measuring Antihydrogen Fall
The main goal of the AEGIS experiment at the CERN Antiproton Decelerator is
the test of fundamental laws such as the Weak Equivalence Principle (WEP) and
CPT symmetry. In the first phase of AEGIS, a beam of antihydrogen will be
formed whose fall in the gravitational field is measured in a Moire'
deflectometer; this will constitute the first test of the WEP with antimatter.Comment: Presented at the Fifth Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, June 28-July 2, 201
Temporal evolution of solar energetic particle spectra
During solar flares and coronal mass ejections, solar energetic par- ticles (SEPs) may be released into the interplanetary medium and near-Earth locations. The energy spectra of SEP events at 1 AU are typically averaged over the entire event or studied in a few snapshots. In this paper we analyze the time evolution of the energy spectra of four large selected SEP events using a large number of snapshots. We use a multi-spacecraft and multi-instrument approach for the observations, obtained over a wide SEP energy range. We find large differences in the spectra at the beginning of the events as measured by different instruments. We show that over time, a wave-like structure is observed traveling through the spectra from the highest energies to the lowest energies, creating an “arch” shape which then straightens into a power law later in the event, after times of the order of 10 hours. We discuss the processes that determine SEP intensities and their role in shaping the spectral time evolution
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