JUMPING FROG METHOD FOR OPTIMAL CLASSIFICATIONS

In the article the problem of finding optimal classifications on a finite set is investigated. It is shown that the problem of finding an optimal classification is generated by a tolerance relation on a finite set. It is also reduced to an optimization problem on a set of permutations. It is proposed a modification of the mixed jumping frogs to find suboptimal solutions of the problem of classification.In the article the problem of finding optimal classifications on a finite set is investigated. It is shown that the problem of finding an optimal classification is generated by a tolerance relation on a finite set. It is also reduced to an optimization problem on a set of permutations. It is proposed a modification of the mixed jumping frogs to find suboptimal solutions of the problem of classification

Accelerator complex based on DC-60 cyclotron

DC-60 heavy ion accelerator, put into operation in 2006, according to its specifications - spectrum, charge and energy of accelerated ions, has the high scientific, technological and educational potential. The highest possible universality both by spectrum of accelerated ions and acceleration energy and regimes was built in DC-60 heavy ion accelerator designing. The new interdisciplinary research complex based on cyclotron DC-60 makes it possible to create a highly-developed scientific-technological and educational environment in the new capital of Kazakhstan..

Effect of ECAP on microstructure and mechanical properties of Cu-₁₄Fe microcomposite alloy

In current study the Cu-14%(wt.)Fe alloy was subjected to 1-10 ECAP passes via route A and, in addition, to 4 passes via routes Bc and C. Microstructure of the alloy after ECAP was characterized using SEM and EBSD analysis. It was shown that the refinement of Fe particles largely depended on the processing route: route A was the most efficient and route Bc was the less efficient. After 10 passes via route A the average thickness of Fe particles decreased to about 3 μm from about 10 μm in initial state. However, the microstructure development in Cu matrix was found to be not dependent much on ECAP route – the average grain/subgrain reached value of about 0.25 μm (according to EBSD analysis) after 4 passes. The mechanical properties of the alloy were also found to be not sensitive to ECAP route

Accelerator complex based on DC-60 cyclotron

DC-60 heavy ion accelerator, put into operation in 2006, according to its specifications - spectrum, charge and energy of accelerated ions, has the high scientific, technological and educational potential. The highest possible universality both by spectrum of accelerated ions and acceleration energy and regimes was built in DC-60 heavy ion accelerator designing. The new interdisciplinary research complex based on cyclotron DC-60 makes it possible to create a highly-developed scientific-technological and educational environment in the new capital of Kazakhstan..

Millisecond-range electron spin memory in singly-charged InP quantum dots

We report millisecond-range spin memory of resident electrons in an ensemble of InP quantum dots (QDs) under a small magnetic field of 0.1 T applied along the optical excitation axis at temperatures up to about 5 K. A pump-probe photoluminescence (PL) technique is used for optical orientation of electron spins by the pump pulses and for study of spin relaxation over the long time scale by measuring the degree of circular polarization of the probe PL as a function of pump-probe delay. Dependence of spin decay rate on magnetic field and temperature suggests two-phonon processes as the dominant spin relaxation mechanism in this QDs at low temperatures.Comment: 3 pages, 4 figures, submitted to Appl. Phys. Let

Zero-field spin quantum beats in charged quantum dots

Spins of resident electrons in charged quantum dots (QD’s) act as local magnets inducing the Zeeman splitting of excitons trapped into dots. This is evidenced by the observation of quantum beats in the linearly polarized time-resolved photoluminescence of a biased array of self-assembled InP QD’s. An external magnetic field is found to shorten the spin beats’ decay time keeping constant the frequency of the beats. A model using the pseudospin formalism allows one to attribute the observed quantum beats to the radiative decay of hot trions having two electrons that occupy different energy levels in a QD

DEVELOPMENT OF NITROFURAN DERIVATIVE: COMPOSITION AND TECHNOLOGY OF EFFERVESCENT TABLETS WITH SOLID DISPERSIONS

Taking into account the current Product specification file, the aim of the work was to develop the composition and technology for obtaining effervescent tablets based on solid dispersions of furazolidone in the form of an aqueous solution for external use.Materials and methods. The used substances were: furazolidone, anhydrous sodium carbonate (chemically pure), polyvinylpyrrolidone-24000±2000 (chemically pure), malic acid (analytically pure), tartaric acid (chemically pure), citric acid (chemically pure), sodium benzoate (chemically pure), ethyl alcohol 96% (chemically pure), purified water. Preparation of granulates is separate wet granulation in a fluidized bed (Mycrolab, BOSCH, Germany). Obtaining tablets is the process of pressing on a manual hydraulic test press ("PRG", VNIR, Russia). The dependence of disintegration, abrasion capacity and crushing resistance on compacting pressure was investigated. Technological parameters of granulates, еру obtained effervescent tablets, shelf life and storage conditions were investigated according to the State Pharmacopoeia of the Russian Federation XIVth ed.Results. Two compositions of effervescent tablets containing solid dispersions of furazolidone as an active substance were obtained, which, when dissolved in 100 ml of water at room temperature (20°C), form a solution of furazolidone with a concentration of 0.004% in less than 5 minutes. The method of quantitative determination of the furazolidone content in the effervescent tablets was validated. A complex of physicochemical methods for the analysis of tablets was carried out. Quality standards have been developed. The developed compositions stability of instant tablets during storage during accelerated and long-term tests has been experimentally confirmed. The preliminary shelf life and storage conditions have been determined.Conclusion. The result of technological and chemical-pharmaceutical research is the creation and evaluation of the quality of a new instant furazolidone dosage form as effervescent tablet formulations

Установление метрологических параметров методики измерений массовой доли белка методом Кьельдаля в пищевой рыбной продукции

In laboratory practice, there are many protein quantification methods, and all of them have their own advantages and disadvantages. The most common and widely used method for the protein analysis in food products, including fish, is the Kjeldahl method. However, the current standards for measurement methods for the determination of the protein content in fish food products do not provide for the use of devices that meet the modern level of technical development, and also do not contain metrological indicators that guarantee the reliability of the results obtained. The aim of the study was to substantiate the method for measuring the protein mass fraction in fish food products by the Kjeldahl method on an automatic analyzer and to establish metrological parameters. The assessment of the quality indicators of the Kjeldahl measuring method was carried out using a Kjeltec System 2300 Nitrogen Analyzer (Foss Analytical AB, Sweden) in the form of a characteristic of the measurement error and its components, which will provide results with the required accuracy.В лабораторной практике существует множество методов определения количества белка и все они имеют свои преимущества и недостатки. Наиболее распространенным и широко используемым методом анализа белка в пищевой продукции, в том числе рыбной, является метод Кьельдаля. Однако при определении содержания белка в пищевой рыбной продукции действующие стандарты на методы измерений не предусматривают использование приборов, отвечающих современному уровню технического развития, а также не содержат метрологические показатели, гарантирующие достоверность полученных результатов. Целью исследования являлось обоснование методики измерений массовой доли белка методом Кьельдаля на автоматическом анализаторе и установление метрологических параметров. Проведена оценка показателей качества методики измерений методом Кьельдаля с использованием анализатора азота Kjeltec System 2300 (Foss Analytical AB, Sweden) в виде характеристики погрешности измерений и ее составляющих, что позволит получать результаты с заданной точностью

Synthesis of accelerograms compatible with the Chinese GB 50011-2001 design spectrum via harmonic wavelets: artificial and historic records

A versatile approach is employed to generate artificial accelerograms which satisfy the compatibility criteria prescribed by the Chinese aseismic code provisions GB 50011-2001. In particular, a frequency dependent peak factor derived by means of appropriate Monte Carlo analyses is introduced to relate the GB 50011-2001 design spectrum to a parametrically defined evolutionary power spectrum (EPS). Special attention is given to the definition of the frequency content of the EPS in order to accommodate the mathematical form of the aforementioned design spectrum. Further, a one-to-one relationship is established between the parameter controlling the time-varying intensity of the EPS and the effective strong ground motion duration. Subsequently, an efficient auto-regressive moving-average (ARMA) filtering technique is utilized to generate ensembles of non-stationary artificial accelerograms whose average response spectrum is in a close agreement with the considered design spectrum. Furthermore, a harmonic wavelet based iterative scheme is adopted to modify these artificial signals so that a close matching of the signals’ response spectra with the GB 50011-2001 design spectrum is achieved on an individual basis. This is also done for field recorded accelerograms pertaining to the May, 2008 Wenchuan seismic event. In the process, zero-phase high-pass filtering is performed to accomplish proper baseline correction of the acquired spectrum compatible artificial and field accelerograms. Numerical results are given in a tabulated format to expedite their use in practice