653 research outputs found
Multistage adaptive testing in the e-learning outcomes’ assessment system
The article discusses the issue of the use of multistage adaptive testing in the system of e-learning results’ assessment. The transition to this format of testing is justified from the standpoint of the effectiveness and efficiency of assessment proceduresВ статье рассматривается вопрос о применение многостадийного адаптивного тестирования в системе оценивания результатов электронного обучения. Обосновывается переход к этому формату тестирования с позиций эффективности и эффициентности оценочных процеду
Conditioned Unitary Transformation on biphotons
A conditioned unitary transformation ( polarization rotation) is
performed at single-photon level. The transformation is realized by rotating
polarization for one of the photons of a polarization-entangled biphoton state
(signal photon) by means of a Pockel's cell triggered by the detection of the
other (idler) photon after polarization selection. As a result, polarization
degree for the signal beam changes from zero to the value given by the idler
detector quantum efficiency. This result is relevant to practical realization
of various quantum information schemes and can be used for developing a new
method of absolute quantum efficiency calibration
Mathematical modeling of solidification process near the inner core boundary of the Earth
Radially symmetric analytic solutions of the heat and mass transfer equations governing convection in the Earth's fluid core are found in terms of deviations from the adiabatic reference state. We demonstrate that an increase of the convective velocity leads to a decrease of the light constituent mass fraction and specific entropy. Where fluid is rising/descending, convective motions decrease/increase the mass fraction and entropy at the inner core boundary (ICB). The influence of convective motions on the thermal fluxes at the core mantle boundary is studied. On the basis of exact solutions we demonstrate that the liquid is supercooled near the ICB. An important point is that an increase in the convective velocity directed to the ICB increases the constitutional supercooling. We show that the anelastic model (AM) can be used only at small supercoolings near the ICB. The most probable solidification scenario "constitutional supercooling and morphological instability" should be described by a mushy layer theory near the ICB and by the AM in the rest region of the fluid outer core. On the basis of dendritic theory and selection mechanisms of crystal growth the dendrite tip radius and interdendritic spacing in the mushy layer at the ICB are determined in the presence of convection. © 2013 Elsevier Inc
Assessment of pharmacological activity and bioavailability of the new derivative 1,3,4-thiadiazole
Acexazolamide is a new derivative of 1,3,4-thiadiazole and acexamic acid. In animal experiments, acute toxicity, pharmacological activity and bioavailability of acexazolamide were evaluate
Sea Ice Dynamics Induced by External Stochastic Fluctuations
The influence of stochastic fluctuations in the atmosphere and in the ocean caused by different occasional phenomena (noises) on dynamic processes of sea ice growth with a mushy layer is studied. It is shown that atmospheric temperature variances substantially increase the sea ice thickness, whereas dispersion variations of turbulent flows in the ocean to a great extent decrease the ice content produced by false bottom evolution. © 2013 Springer Basel
Solidification dynamics under random external-temperature fluctuations
The nonlinear dynamic mechanisms of solid-phase formation with a phase transition region are studied under periodic and random fluctuations of the cooling-boundary temperature. It is theoretically shown that a mushy zone can form even at close liquid and cooling-boundary temperatures due to random temperature field fluctuations. The growth of a solid phase with the mushy zone is investigated as a function of the autocovariance characteristics of random noises. © 2013 Pleiades Publishing, Ltd
Status of the FLUTE RF System Upgrade
FLUTE (Ferninfrarot Linac- Und Test-Experiment) is a compact versatile linac-based accelerator test facility at KIT. Its main goal is to serve as a platform for a variety of accelerator studies and to generate strong ultra-short THz pulses for photon science. It will also serve as an injector for a Very Large Acceptance compact Storage Ring (VLA-cSR), which will be realized at KIT in the framework of the compact STorage Ring for Accelerator Research and Technology (cSTART) project. To achieve acceleration of electrons in the RF photoinjector and LINAC (from FLUTE) with high stability, it is necessary to provide stable RF power. For this goal, an upgrade of the existing RF system design has been proposed and is currently being implemented. This contribution will report on the updated RF system design and the commissioning status of the new RF system components
- …