Cosmic ray modulation in a random anisotropic magnetic field

Inhomogeneities of the interplanetary magnetic field can be divided into small scale and large scale ones as may be required by the character of the problem of cosmic ray (CR) propagation. CR propagation in stochastic magnetic fields is of diffusion character. The main contribution into the scattering of CR particles is made by their interaction with inhomogeneities of the magnetic field H which have characteristic dimensions 1 of the order of Larmor radius R=cp/eH of particle (p is the absolute value of particle momentum, e is particle charge, c is velocity of light). Scattering of particles on such inhomogeneities leads to their diffusion mostly along a magnetic field with characteristic dimensions of variation in space exceeding the mean free path

Anomalous cyclotron mass dependence on the magnetic field and Berry’s phase in (Cd₁-x-γZnxMnγ)₃As₂ solid solutions

Shubnikov-de Haas (SdH) effect and magnetoresistance measurements of single crystals of diluted II-V magnetic semiconductors (Cd₁-x-γZnxMnγ)₃As₂ (x+γ= 0.4, y=0.04 and 0.08) are investigated in the temperature range T=4.2 ÷ 300 K and in transverse magnetic field B=0 ÷ 25

Magnetoresistance and Anomalous Hall Effect of InSb Doped with Mn

Transport properties of polycrystalline (In, Mn)Sb samples are investigated. Behavior of the temperature and magnetic field dependencies of the resistivity, anomalous Hall coefficient and magnetoresistivity at low temperatures points out the influence of Mn complexes, Mn ions and nano- and microsizes MnSb precipitates on charge transport. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3361

Визначення залежності характеристик компресійної піни

One of the promising ways to combat forest fires is considered. The authors suggest using compression foam as an extinguishing agent instead of ordinary water, which has several advantages. Unlike conventional foam, it has special properties that are not characteristic of the ordinary foam, such as increased stability, enhanced adhesion and fire extinguishing ability while reducing the flow of water and foaming agent. In order to increase the effective use of this extinguishing medium, we performed the theoretical substantiation of the dependence of operational characteristics of the compression foam depending on the geometric dimensions and homogeneity of the bubbles it is made up if. The notion of conditional relative strength of the bubble as a value of the ratio of the area of ​​the central transverse section of the bubble to its bubble mass is introduced and the formulas for its deduction are given. The experimental dependences of the operational characteristics of the compression foam on the geometrical sizes and the homogeneity of the bubbles forming it, which will allow creating effective systems for the formation of a compressive foam, and controlling the processes of foaming and fire extinguishing, are presented. The results of the studies confirm that the values ​​of the diameters of the bubbles of the compression foam and their homogeneity, characterized by the polydispersity of the foam, determine its multiplicity, which in turn determines the stability and adhesion properties of the foam. With an increase in the frequency of foam, the polydispersity decreases, i.e., homogeneity increases. It has been proved that there is a direct relationship between the operational characteristics of the compression foam such as the foam stability, the adhesive property of the foam, the fire-extinguishing ability of the foam and its geometric characteristics – the size of the bubbles and their homogeneity, in which the size of the bubbles and their homogeneity (polydispersity) are the determining parameters of compression foam for its performance. Technological solutions aimed at reducing the size of foam bubbles and enhancing their uniformity will lead to improved performance of the compression foam in order to increase the fire-extinguishing capabilities of the compression foam in the fight against forest fires.Проведено теоретичне обґрунтування залежності експлуатаційних характеристик компресійної піни залежно від геометричних розмірів та однорідності бульбашок, що її утворюють. Введено поняття умовної відносної міцності бульбашки як величину відношення площі центрального поперечного перетину бульбашки до її маси бульбашки та наведено формули для його вирахування. Наведено експериментальні залежності експлуатаційних характеристик компресійної піни від геометричних розмірів та гомогенності міхурів, що її утворюють, що дає змогу створювати ефективні системи з утворення КП та здійснювати управління процесами піноутворення та пожежогасіння. Результати досліджень підтверджують, що величини діаметрів міхурів КП та їхня гомогенність, що характеризується полідисперсністю піни, визначають її кратність, яка визначає стійкість та адгезійні властивості піни. У разі збільшення кратності піни, полідисперсність зменшується, тобто гомогенність зростає. Доведено, що існує прямий зв'язок між експлуатаційними характеристиками компресійної піни, такими як: стійкість піни, адгезійна властивість піни, вогнегасна здатність піни та її геометричними характеристиками – розмірами бульбашок та їхня гомогенністю, при чому розміри міхурів та їх гомогенність (полідисперсність) є визначальними параметрами компресійної піни щодо її експлуатаційних характеристик. Технологічні рішення, спрямовані на зменшення розміру бульбашок піни та підвищення її однорідності призведуть до покращення експлуатаційних характеристик компресійної піни та її подальшого впровадження для підвищення ефективності гасіння лісних пожеж

Analytical solution of second Stokes problem of behaviour of rarefied gas with Cercignani boundary accomodation conditions

Analytical solution of second Stokes problem of behaviour of rarefied gas with Cercignani boundary accomodation conditions The second Stokes problem about behaviour of rarefied gas filling half-space is analytically solved. A plane, limiting half-space, makes harmonious fluctuations in the plane. The kinetic BGK-equation (Bhatnagar, Gross, Krook) is used. The boundary accomodation conditions of Cercignani of reflexion gaseous molecules from a wall are considered. Distribution function of the gaseous molecules is constructed. The velocity of gas in half-space is found, also its value direct at a wall is found. The force resistance operating from gas on border is found. Besides, the capacity of dissipation of the energy falling to unit of area of the fluctuating plate limiting gas is obtained.Comment: 26 pages, 5 figure

Electron spin resonance detection and identification of nitrogen centers in nanodiamonds

Individual nitrogen centers N0 and nitrogen pairs N 2 + have been detected and identified in natural diamond nanocrystals by means of the high-frequency electron spin resonance method. The N0 nitrogen centers have been observed in synthetic diamond nanocrystallites with a size of less than 10 nm produced by high-temperature high-pressure sintering of detonation nanodiamonds. Thus, the possibility of the stable state of impurity nitrogen atoms in diamond nanoparticles has been demonstrated. © 2009 Pleiades Publishing, Ltd

Detection and identification of nitrogen centers in nanodiamond: EPR studies

Electron paramagnetic resonance (EPR) and electron spin echo (ESE) at X-band and at high-frequency W-band (95 GHz) have been used to study natural diamond nanocrystals, detonation nanodiamond (ND) with a size of ∼ 4.5 nm and detonation ND after high-temperature, high-pressure sintering with a size of ∼ 8.5 nm. Isolated nitrogen centers N 0 and nitrogen pairs N2+ have been detected and identified, and their structure has been unambiguously determined by means of the high frequency EPR and ESE in natural diamond nanocrystals. In detonation ND and detonation ND after sintering, isolated nitrogen centers N 0 have been discovered in nanodiamond core. In addition EPR signals of multivacancy centers with spin 3/2 seem to be observed in nanodiamond core of detonation ND. Copyright © Taylor & Francis Group, LLC