1,362 research outputs found
Calculation of resonances in the Coulomb three-body system with two disintegration channels in the adiabatic hyperspherical approach
The method of calculation of the resonance characteristics is developed for
the metastable states of the Coulomb three-body (CTB) system with two
disintegration channels. The energy dependence of K-matrix in the resonance
region is calculated with the use of the stabilization method. Resonance
position and partial widths are obtained by fitting the numerically calculated
K(E)-matrix with the help of the generalized Breit-Wigner formula.Comment: Latex, 11 pages with 5 figures and 2 table
Multilevel Analysis of Oscillation Motions in Active Regions of the Sun
We present a new method that combines the results of an oscillation study
made in optical and radio observations. The optical spectral measurements in
photospheric and chromospheric lines of the line-of-sight velocity were carried
out at the Sayan Solar Observatory. The radio maps of the Sun were obtained
with the Nobeyama Radioheliograph at 1.76 cm. Radio sources associated with the
sunspots were analyzed to study the oscillation processes in the
chromosphere-corona transition region in the layer with magnetic field B=2000
G. A high level of instability of the oscillations in the optical and radio
data was found. We used a wavelet analysis for the spectra. The best
similarities of the spectra of oscillations obtained by the two methods were
detected in the three-minute oscillations inside the sunspot umbra for the
dates when the active regions were situated near the center of the solar disk.
A comparison of the wavelet spectra for optical and radio observations showed a
time delay of about 50 seconds of the radio results with respect to optical
ones. This implies a MHD wave traveling upward inside the umbral magnetic tube
of the sunspot. Besides three-minute and five-minute ones, oscillations with
longer periods (8 and 15 minutes) were detected in optical and radio records.Comment: 17 pages, 9 figures, accepted to Solar Physics (18 Jan 2011). The
final publication is available at http://www.springerlink.co
Corrosion resistance of alloys of Hastelloy in chloroaluminate melts
The corrosion of Hastelloy S, Hastelloy X, Haynes 230, Hastelloy N, Hastelloy G35 and Hastelloy C2000 alloys was studied in KCl-AlCl3 melts at 550°С. The rates and the mechanisms of corrosion of the studied materials were determined. The processes taking place during the interaction between alloys and chloroaluminate melts were investigated
Nash equilibrium design in the interaction model of entities in the customs service system
The urgency of the analyzed issue is due to the importance of the use of economic-mathematical tools in the course of modeling the interaction of the entities in the customs service system that is necessary for the development of foreign economic activity (FEA) of any state. The purpose of the article is to identify effective strategies for the interaction between the participants of foreign trade activities with customs brokers. The leading method to the study of this issue is economic-mathematical modeling, allowing studying the process of making decisions while choosing the strategy of cooperation between the customs broker and his client. Results: the article suggests the mathematical model to optimize the management mechanisms of interaction between enterprises, engaged in foreign trade, and customs dealers. The data of this article may be useful in modeling interaction of the entities in the customs service system using the methods of game theory. The model of “customer - customs broker” is implemented as a bimatrix game. Assuming the noncooperativegame the authors solve the problem of finding Nash equilibrium in mixed strategies. © 2016 Fedorenko et al
Separation of a binary mixture with a large mass difference between the components in a gas centrifuge
The separation of a binary gaseous mixture of uranium hexafluoride 238UF6 with different light components in a high-speed centrifuge, intended for separating heavy isotopes, is examined. The mass of the light impurities is varied in the range M 1 = 0.02-0.349 kg/mole. It is shown that as the impurity mass decreases the structure of the flow fields in the centrifuge rotor changes considerably. If in the case of a mixture of heavy isotopes convective transport has a determining effect on the concentration, for a mixture with a large difference of the mass of the components radial barodiffusion in a centrifugal field becomes primary, which results in the appearance of a maximum of the separation factor at M 1 = 0.127 kg/mole. © 2013 Springer Science+Business Media New York
Joule Heating and Current-Induced Instabilities in Magnetic Nanocontacts
We consider the electrical current through a magnetic point contact in the
limit of a strong inelastic scattering of electrons. In this limit local Joule
heating of the contact region plays a decisive role in determining the
transport properties of the point contact. We show that if an applied constant
bias voltage exceeds a critical value, the stationary state of the system is
unstable, and that periodic, non-harmonic oscillations in time of both the
electrical current through the contact and the local temperature in the contact
region develop spontaneously. Our estimations show that the necessary
experimental conditions for observing such oscillations with characteristic
frequencies in the range Hz can easily be met. We also show a
possibility to manipulate upon the magnetization direction of a magnetic grain
coupled through a point contact to a bulk ferromagnetic by exciting the
above-mentioned thermal-electric oscillations.Comment: 9 pages, 6 figures, submitted to Physical Review
Ultrasound-assisted cold pasteurization in liquid or SC-CO2
Various types of chemical and physical protocols are used, thermal treatment in particular, to increase the quality of bulk food products (for example, dates or some sort of nuts) and extend shelf life, and combinations of methods are frequently used to achieve the best results. However, the use of these processing methods is not always the best option to preserve the initial taste and appearance of food products. For instance, a product may lose its initial natural appearance and acquire different flavors due to chemical transformations that occur at certain temperatures or when the products are treated with chemicals. Non-thermal treatment methods are called “cold” pasteurization. This is a set of advanced techniques that are based on physical and chemical effects that do not result in the structural food-product transformations caused by heating. We have developed and tested a new technique for efficient food-product processing and cold pasteurization in an ultrasonic field under pressure in an atmosphere of supercritical or subcritical carbon dioxide. A laboratory-scale unit that was designed and built for this purpose has experimentally proven the feasibility of this process and demonstrated high efficiency in suppressing pathogenic flora
Spectroelectrochemical study of stainless steel corrosion in NaCl-KCl melt
High-temperature spectroelectrochemestry was applied to study corrosion of various types of stainless steel in molten salts. The electronic absorption spectra of products of anodic dissolution of stainless steel major components (iron, chromium, nickel, molybdenum, manganese, titanium) were measured in NaCl-KCl melt at 750 °C The effectiveness and limitations of applying spectroscopic method for studying alloys corrosion was demonstrated on example of anodic dissolution of AISI 316L, 316Ti and 321 austenitic steels. The major corrosion products of steels are iron, manganese and chromium species. Prolongation of anodic dissolution leads to increasing chromium-to-iron ratio in the melt. Titanium in steels forms very stable carbonitride species that aren't dissolved during anodic oxidation. © The Electrochemical Society.Physical and Analytical Electrochemistry;Electrodeposition;Energy Technolog
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