Multiphoton Transitions in a Spin System Driven by Strong Bichromatic Field

EPR transient nutation spectroscopy is used to measure the effective field (Rabi frequency) for multiphoton transitions in a two-level spin system bichromatically driven by a transverse microwave (MW) field and a longitudinal radio-frequency (RF) field. The behavior of the effective field amplitude is examined in the case of a relatively strong MW field, when the derivation of the effective Hamiltonian cannot be reduced to first-order perturbation theory in w_{1} / w_{rf} (w_{1} is the microwave Rabi frequency, w_{rf} is the RF frequency). Experimental results are consistently interpreted by taking into account the contributions of second and third order in w_{1} / w_{rf} evaluated by Krylov-Bogolyubov-Mitropolsky averaging. In the case of inhomogeneously broadened EPR line, the third-order correction modifies the nutation frequency, while the second-order correction gives rise to a change in the nutation amplitude due to a Bloch-Siegert shift.Comment: 7 pages, 6 figure

New Super Calogero Models and OSp(4|2) Superconformal Mechanics

We report on the new approach to constructing superconformal extensions of the Calogero-type systems with an arbitrary number of involved particles. It is based upon the superfield gauging of non-abelian isometries of some supersymmetric matrix models. Among its applications, we focus on the new N=4 superconformal system yielding the U(2) spin Calogero model in the bosonic sector, and the one-particle case of this system, which is a new OSp(4|2) superconformal mechanics with non-dynamical U(2) spin variables. The characteristic feature of these models is that the strength of the conformal inverse-square potential is quantized.Comment: 12 pages, talk presented by E.Ivanov at the XIII International Conference "Symmetry Methods in Physics", Dubna, July 6-9, 200

Effective Field and the Bloch-Siegert Shift at Bihromatic Excitation of Multiphoton EPR

The dynamics of multiphoton transitions in a two-level spin system excited by transverse microwave and longitudinal RF fields with the frequencies w_{mw} and w_{rf}, respectively, is analyzed. The effective time-independent Hamiltonian describing the "dressed" spin states of the "spin + bichromatic field" system is obtained by using the Krylov-Bogoliubov-Mitropolsky averaging method. The direct detection of the time behavior of the spin system by the method of nonstationary nutations makes it possible to identify the multiphoton transitions for resonances w_{0} = w_{mw} + rw_{rf} (w_{0} is the central frequency of the EPR line, r = 1, 2), to measure the amplitudes of the effective fields of these transitions, and to determine the features generated by the inhomogeneous broadening of the EPR line. It is shown that the Bloch-Siegert shifts for multiphoton resonances at the inhomogeneous broadening of spectral lines reduce only the nutation amplitude but do not change their frequencies.Comment: 6 pages, 5 figure

Taming the zoo of supersymmetric quantum mechanical models

We show that in many cases nontrivial and complicated supersymmetric quantum mechanical (SQM) models can be obtained from the simple model describing free dynamics in flat complex space by two operations: (i) Hamiltonian reduction and (ii) similarity transformation of the complex supercharges. We conjecture that it is true for any SQM model.Comment: final version published in JHE

Justification of an asymptotic expansion at infinity

A family of asymptotic solutions at infinity for the system of ordinary differential equations is considered. Existence of exact solutions which have these asymptotics is proved.Comment: 8 page

Влияние молочнокислых продуктов на качественные показатели мясного сырья для производства сырокопченых колбас

Conducted research pertains to technologies of animal products processing and the development of biotechnological methods for stabilizing microbial and enzymatic biological leaven for meat.Materials and Methods. The studies were conducted in the conditions of the Research Institute of Food and Animal Processing Technologies and Laboratory of Microbiological Research Methods, Department of Microbiology of Bila Tserkva National Agrarian University. Moisture retaining capacity and bacterial contamination of beef and pork were determined.Results. The effect of processing raw meat with lactic acid product – yogurt on the moisture retaining capacity was experimentally established. With the highest titratable acidity of yoghurt of 100-110 °T, the moisture retaining capacity of pork and beef was inferior to control on 2.13 and 1.29 % and amounted to 51.88 and 62.73 %. Under a titratable acidity of lactic acid beverage of 100-110 °T with total number of lactic acid bacteria on the surface of raw meat, it was 8.1×108 and 8.5×108, which prevailed samples with acidity level of 60-70 °T on 24.5 and 24.3 %.Conclusions. The results of studies have revealed the effect of processing raw meat by yogurt with different titratable acidity on moisture retaining capacity and bacterial contamination.Проведенные исследования относятся к технологиям переработки продуктов животноводства и отработки биотехнологических способов стабилизации микробных и ферментативных биологических заквасок для мяса. Исследования проводили в условиях Научно-исследовательского института пищевых технологий и технологий переработки продуктов животноводства и лаборатории микробиологических методов исследований кафедры микробиологии Белоцерковского национального аграрного университета. Определяли влагоудерживающую способность и бактериальное обсеменение мясной сырья крупного рогатого скота и свиней. Экспериментально установлено влияние обработки мясного сырья молочнокислые продукты йогуртом на влагоудерживающую способность. При высочайшем титруемой кислотности йогурта 100–110 °Т влагоудерживающую способность свинины и говядины уступала контроля на 2,13 и 1,29 % и составляла 51,88 и 62,73 %. По титруемой кислотности молочнокислого напитка 100–110 °Т, где общее количество молочнокислых бактерий на поверхности мясного сырья была 8.1×108 and 8.5×108, преобладали опытные образцы с уровнем кислотности 60–70 °Т на 24,5 и 24,3 %. Результатами исследований выявлено влияние обработки мясного сырья йогуртом с разной титруемая кислотность на влагоудерживающую способность и бактериальное обсеменение

Event-B Patterns for Specifying Fault-Tolerance in Multi-Agent Interaction

Interaction in a multi-agent system is susceptible to failure. A rigorous development of a multi-agent system must include the treatment of fault-tolerance of agent interactions for the agents to be able to continue to function independently. Patterns can be used to capture fault-tolerance techniques. A set of modelling patterns is presented that specify fault-tolerance in Event-B specifications of multi-agent interactions. The purpose of these patterns is to capture common modelling structures for distributed agent interaction in a form that is re-usable on other related developments. The patterns have been applied to a case study of the contract net interaction protocol

Superconformal Yang-Mills quantum mechanics and Calogero model with OSp(N|2,R) symmetry

In spacetime dimension two, pure Yang-Mills possesses no physical degrees of freedom, and consequently it admits a supersymmetric extension to couple to an arbitrary number, N say, of Majorana-Weyl gauginos. This results in (N,0) super Yang-Mills. Further, its dimensional reduction to mechanics doubles the number of supersymmetries, from N to N+N, to include conformal supercharges, and leads to a superconformal Yang-Mills quantum mechanics with symmetry group OSp(N|2,R). We comment on its connection to AdS_2 \times S^{N-1} and reduction to a supersymmetric Calogero model.Comment: 1+28 pages, no figure; Refs added. To appear in JHE