Polarization observables in high-energy deuteron photodisintegration within the Quark-Gluon Strings Model

Deuteron two-body photodisintegration is analysed within the framework of the Quark-Gluon Strings Model. The model describes fairly well the recent experimental data from TJNAF in the few GeV region. Angular distributions at different $\gamma$-energies are presented and the effect of a forward-backward asymmetry is discussed. New results from the QGSM for polarization observables from 1.5 -- 6 GeV are presented and compared with the available data.Comment: 3 pages, LaTeX, 4 postscript figures; contribution to QNP2002, Juelich, June 10-14, 200

ϕ\phi meson production in sNN\sqrt{s_{NN}} = 200 GeV Au+Au and pp collisions at RHIC

We present the results for the measurement of $\phi$ meson production in $\sqrt{s_{NN}}$ = 200 GeV Au+Au and pp collisions at the Relativistic Heavy Ion Collider (RHIC). Using the event mixing technique, spectra and yields are obtained from the $\phi\to K^{+}K^{-}$ decay channel for different centrality bins in Au+Au collisions and in pp collisions. We observe that the spectrum shape in Au+Au collisions depends weakly on the centrality and the shape of the spectrum in pp collisions is significantly different from that in Au+Au collisions. In Au+Au collisions, the extracted yield of $\phi$ meson is flat as a function of rapidity; The $$ of $\phi$, extracted from the fit function to the spectra, shows a different behavior as a function of centrality than that of $\pi^-$, $K^-$ and $\bar{p}$Comment: Proceedings for the 7th International Conference on Strangeness in Quark Matte

Interference of nonpolarized light in liquid crystal domains on the polymer surface

The interference of the nonpolarized light transmitted through an ensemble of nematic liquid crystal domains formed on the polycarbonate surface has been investigated. A model based on the superposition of the ordinary and extraordinary beams passed through domains with the radial structure has been developed. Expressions for the phase difference and intensity of the interfering beams, which take into account the distribution of the liquid crystal director field, have been derived. The dependences of the optical transmittance of a domain layer on the applied voltage have been calculated with regard to the material and optical constants of a liquid crystal and structural features and averaged morphological parameters of individual domains in the experimental sample. The results of the calculation are consistent with the experimental data, which confirms the validity of the proposed model

Microwave properties of HTS films: measurements in millimeter wave range

A theoretical and experimental justification of an approach proposed and developed by us for surface impedance standard measurements of HTS films is presented. An analysis of the electromagnetic properties of quasi-optical dielectric resonators with conducting endplates, which provides a theoretical background for studies of HTS films in the millimeter wave range, is performed. With this technique, the highest-quality modes, namely whispering gallery modes, are excited in a dielectric cylindrical disc sandwiched between HTS films. Considerable enhancement of the sensitivity of surface resistance measurements in the millimeter wave range is demonstrated, which is important for the fundamental investigation of superconductor physics. It is also shown that the measured frequency shift in the resonator with the HTS endplates as a function of the temperature reveals a possibility for accurate evaluation of the field penetration depth in HTS films

Light interference in a hybrid-aligned nematic layer with nonordered surface disclination lines

The propagation of a laser beam through a hybrid-aligned nematic layer with a surface disclination line has been investigated. A model of the light interference has been developed to consider the scattering by the structural inhomogeneities. The analytical expression that includes the factor characterizing an exponential decrease in the light scattering has been obtained. The dependence of the intensity of light transmitted through the layer on the magnetic field has been measured. The dependence has been accompanied by the interference oscillations. The theoretical expression is consistent with the experiment, which confirms the correctness of the model concepts

Підвищення точності визначення кількісних параметрів руху крові в ультразвукових доплерівських системах

By means of determining the dependence of blood flow rate and different indices on the spectral characteristics of the ultrasonic Doppler response of blood flow the issue of improving the measurement efficiency of vascular system diagnostic parameters is studied. It is shown that instantaneous power of the Doppler signal allows to draw the conclusion about varying of blood flow diameter during the cardiocycle. On the basis of the analytical expressions for the instantaneous power of the Doppler signal, which consider the focusing of waves at an arbitrary ratio between duration of the probing pulses and blood vessel diameter, the expressions for Stuart, Gosling and Pourcelot indices as well as blood flow rate are derived. These expressions allow to set the degree of the diagnostic value of the proposed new indices of blood flow and improve the method of determining blood flow rate in ultrasound Doppler systems. References 17, figures 5В работе исследован вопрос о повышении эффективности измерения диагностических параметров кровеносной системы путем определения зависимости расхода крови и различных индексов кровотока от спектральных характеристик ультразвукового доплеровского отклика потоков крови. Показано, что мгновенная мощность доплеровского сигнала позволяет судить об изменении диаметра потока крови за кардиоцикл. На основе аналитических выражений для мгновенной мощности доплеровского сигнала, учитывающих фокусирование волн при произвольном соотношении между длительностью зондирующих импульсов и диаметром кровеносного сосуда, в работе получены выражения для индексов Стюарта, Гослинга и Пурсело, а также расхода крови, определяемых в ультразвуковых доплеровских системах. Найденные выражения позволяют установить степень диагностической ценности новых предложенных индексов потоков крови и уточнить методику определения расхода крови в процессе ультразвуковых диагностических исследований.Библ. 17, рис. 5.У роботі досліджене питання про підвищення ефективності вимірювання діагностичних параметрів кровоносної системи шляхом визначення залежності витрати крові та різних індексів кровотоку від спектральних характеристик ультразвукового доплерівського відгуку потоків крові. Показано, що миттєва потужність доплерівського сигналу дозволяє судити про зміну діаметра потоку крові за кардіоцикл. На підставі аналітичних виразів для миттєвої потужності доплерівського сигналу, які враховують фокусування хвиль при довільному співвідношенні між тривалістю зондувальних імпульсів та діаметром кровоносної судини, в роботі отримані вирази для індексів Стюарта, Гослінга і Пурсело, а також витрати крові, що визначаються в ультраз вукових доплерівських системах. Знайдені вирази дозволяють встановити ступінь діагностичної цінності нових запропонованих індексів потоку крові і уточнити методику визначення витрати крові в процесі ультразвукових діагностичних досліджень. Бібл. 17, рис. 5