Homogeneous spaces with symmetries

We give a brief survey of main recent results about invariant pseudo-Riemannian metrics and classical affinor structures on homogeneous spaces with symmetries obtained by the participants of the joint BRFFI-RFFI project “Homogeneous spaces with symmetries”

Advanced Photodetectors for Hyperspectroscopy and Other Applications

Hyperspectroscopy is a new method of surface image taking, providing simultaneously high position and spectral resolutions which allow one to make some conclusions about chemical compositions of the surfaces. We are now studying applications of the hyperspctroscopic technique to be used for medicine. This may allow one to develop early diagnostics of some illnesses, as for example, skin cancer. For image taking advanced MCPs are currently used, sensitive in the spectral interval of 450-850 nm. One of the aims of this work is to extend the hyperspectrocpic method to the UV region of spectra: 185-280 nm. For this we have developed and successfully tested innovative 1D and 2D UV sealed photosensitive gaseous detectors with resistive electrodes. These detectors are superior MCPs due to the very low rate of noise pulses and thus due to the high signal to noise ratio. Other important features of these detectors are that they have excellent position resolutions - 30 micron in digital form, are vibration stable and are spark protected. The first results from the application of these detectors for spectroscopy, hyperspectroscopy and the flame detection are presented.Comment: Presented at the IEEE Nuclear Science Syposium, Puerto Rico, October 200

The first applications of novel gaseous detectors for UV visualization

We have demonstrated experimentally that recently developed gaseous detectors combined with solid or gaseous photo-cathodes have exceptionally low noise and high quantum efficiency for UV photons while being solar blind. For this reason they can be used for the detection of weak UV sources in daylight conditions. These detectors are extremely robust, can operate in poor gas conditions and are cheap. We present the first results of their applications to hyper-spectroscopy and flame detection in daylight conditions

The Energy Level Shifts, Wave Functions and the Probability Current Distributions for the Bound Scalar and Spinor Particles Moving in a Uniform Magnetic Field

We discuss the equations for the bound one-active electron states based on the analytic solutions of the Schrodinger and Pauli equations for a uniform magnetic field and a single attractive $\delta({\bf r})$-potential. It is vary important that ground electron states in the magnetic field differ essentially from the analogous state of spin-0 particles, whose binding energy was intensively studied more than forty years ago. We show that binding energy equations for spin-1/2 particles can be obtained without using the language of boundary conditions in the $\delta$-potential model developed in pioneering works. We use the obtained equations to calculate the energy level displacements analytically and demonstrate nonlinear dependencies on field intensity. We show that the magnetic field indeed plays a stabilizing role in considered systems in a case of the weak intensity, but the opposite occurs in the case of strong intensity. These properties may be important for real quantum mechanical fermionic systems in two and three dimensions. We also analyze the exact solution of the Pauli equation for an electron moving in the potential field determined by the three-dimensional $\delta$-well in the presence of a strong magnetic field. We obtain asymptotic expressions for this solution for different values of the problem parameters. In addition, we consider electron probability currents and their dependence on the magnetic field. We show that including the spin in the framework of the nonrelativistic approach allows correctly taking the effect of the magnetic field on the electric current into account. The obtained dependencies of the current distribution, which is an experimentally observable quantity, can be manifested directly in scattering processes, for example.Comment: 31 pages, 10 figure

Charge relaxation resistance in the Coulomb blockade problem

We study the dissipation in a system consisting of a small metallic island coupled to a gate electrode and to a massive reservoir via single tunneling junction. The dissipation of energy is caused by a slowly oscillating gate voltage. We compute it in the regimes of weak and strong Coulomb blockade. We focus on the regime of not very low temperatures when electron coherence can be neglected but quantum fluctuations of charge are strong due to Coulomb interaction. The answers assume a particularly transparent form while expressed in terms of specially chosen physical observables. We discovered that the dissipation rate is given by a universal expression in both limiting cases.Comment: 21 pages, 12 figure

A SKELETON FEATURES-BASED FALL DETECTION USING MICROSOFT KINECT V2 WITH ONE CLASS-CLASSIFIER OUTLIER REMOVAL

The real-time and robust fall detection is one of the key components of elderly people care and monitoring systems. Depth sensors, as they became more available, occupy an increasing place in event recognition systems. Some of them can directly produce a skeletal description of the human figure for compact representation of a person’s posture. Skeleton description makes the output of source video or detailed information about the depth outside the system unnecessary and raises the privacy of the entire system. Based on a comparative study of different RGB-D cameras, the most promising model for further development was chosen - Microsoft Kinect v2. The TST Fall Detection Dataset v2 is used here as a base for experiments. The proposed algorithm is based on the skeleton features encoding on the sequence of neighboring frames and support vector machine classifier. A version of a cumulative sum method is applied for combining the individual decisions on the consecutive frames. It is offered to use the one-class classifier for detection of low-quality skeletons. The 0.958 accuracy of our fall detection procedure was obtained in the cross-validation procedure based on the removal of records of a particular person from the database (Leave-one-Person-out)

Effect of Bacillus pumilus ribonuclease on the paramagnetic centers of microbial cells

The potential clinical application of Bacillus pumilus cytotoxic ribonuclease (binase) for selectively inducing the death of tumor cells makes it imperative to investigate its effect on the normal human microflora. Flow cytometry was used to determine that binase concentration causing the apoptosis of cancer cells had no effect of the viability of Escherichia coli K12. The changes in the paramagnetic centers of E. coli K12 cells in the presence of nontoxic binase concentrations revealed by EPR spectroscopy included higher EPR signals from iron-containing proteins (including those from the Fe-S clusters) and of the Mn(II) hyperfine structure. The TMTH spin probe (N-(1-hydroxy-2,2,6,6-tetramethylpiperidine-4-il)-2-methylpropanamide hydrochloride) was used to reveal a twofold increase in the levels of reactive oxygen species (ROS) in the cells, which induced oxidative stress in the enzyme-treated bacteria. Inductively coupled plasma mass spectrometry revealed elevated contents of alkaline (Li, Na, K), alkali earth (Mg, Ca), transition (Cr, Mn, Fe, Cu, Zn), and post-transition metals (Bi, Pb) in the cells. Elevated levels of Cu and Zn (which impair the activity of the respiratory chain enzymes) and of Mn, which is known as a superoxide dismutase cofactor, confirmed development of the oxidative stress in bacteria. © 2013 Pleiades Publishing, Ltd