Regular and chaotic motion domains in the channeling electron's phase space and mean level density for its transverse motion energy

The motion of charged particles in a crystal in the axial channeling regime can be both regular and chaotic. The chaos in quantum case manifests itself in the statistical properties of the energy levels set. These properties have been studied previously for the electrons channeling along direction of the silicon crystal, in the case when the classical motion was completely chaotic. It is demonstrated that the level spacing distribution for both electrons and positrons can be better described by Berry-Robnik distribution than by both Wigner (completely chaotic case) or Poisson (completely regular case) distribution

Levels of Adipokines in Blood of Woman with Threatened Abortion

Purpose: To investigate levels of adipokines and indicators of carbohydrate metabolism in the blood of women with a true threat of pregnancy termination (isthmico-cervical insufficiency). Materials and Methods: The study involved women in the period of 16 – 26 weeks of gestation – 18 women with a true threat of termination of pregnancy and 52 women with physiological pregnancy. Both groups were compared with levels of leptin, resistin, adiponectin, fasting glucose, fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR). Results: In the blood of women with a real threat of pregnancy termination are revealed significant changes in carbohydrate metabolism – the increase in levels of fasting insulin and glucose, and also increase the value of the index of insulin resistance HOMA-IR (p<0.001). No significant differences in age and BMI index were found between the study and control subjects. In the group of women with the true threat of pregnancy termination significantly increases the level of leptin (p=0.04), and there is also a decrease in the concentration of resistin (p=0.02). The level of adiponectin significant does not change.Summary: Compared with the control group, patients with RPL were more likely to have insulin resistance. In condition of the true threat of pregnancy termination increases the level of leptin and reduced the concentration of resistin, and is determined the development of pathological insulin resistance

Bremsstrahlung Suppression due to the LPM and Dielectric Effects in a Variety of Materials

The cross section for bremsstrahlung from highly relativistic particles is suppressed due to interference caused by multiple scattering in dense media, and due to photon interactions with the electrons in all materials. We present here a detailed study of bremsstrahlung production of 200 keV to 500 MeV photons from 8 and 25 GeV electrons traversing a variety of target materials. For most targets, we observe the expected suppressions to a good accuracy. We observe that finite thickness effects are important for thin targets.Comment: 52 pages, 13 figures (incorporated in the revtex LaTeX file

Energy dependence of the efficiency of high-energy negatively charged particle beam deflection by planar channeling in a bent crystal

The study of planar channeling of high-energy negatively charged particles in bent crystals was carried out. The value of the critical radius of planar channeling in the Doyle–Turner approximation for the atomic potential is determined. The dependence of the maximum angle at which a given fraction of beam particles could be deflected by means of planar channeling in a bent crystal on the particle energy was found. We identified the ideal parameters for the exploitation of planar channeling for negatively charged particle beam deflection by planar channeling in a bent crystal at current and future high-energy accelerators, e.g., SLAC, MAMI, ILC or muon colliders

On the possibility of extracting part of a beam of negatively charged particles from an accelerator using a bent crystal

Abstract The efficiency of deflection of high-energy negatively charged particles by a bent crystal using planar channeling and stochastic deflection mechanism is compared. The comparison is carried out on the example of antiprotons with kinetic energy from 1 to 14 GeV, which will be achievable on accelerators of the Facility for Antiproton and Ion Research. The comparison showed that both deflection mechanisms make it possible to deflect a part of the antiproton beam in the specified energy range by angles of the order of several hundred microradians, which significantly exceed the critical angle of planar channeling. At the same time, the stochastic deflection mechanism makes it possible to deflect particles at much larger angles than planar channeling

STUDY OF SURFACE MODIFIED POLYMERS IN THE MODIFICATION OF NANOMATERIALS

The comparative study of change of surface tension of solutions of some commercial rubbers before and after thermal ageing technique du-Nui, analyzed the features of change of surface tension of solutions of various rubbers in the presence of a mixture of fullerenes. Calculations of the Gibbs energy and the analysis of the obtained data to predict the behavior of polymer systems when changes are made to mix of fullerenes in a wide concentration range. When comparing the results of changes in Gibbs energy and the surface tension in fluids rubbers shown that mentioned above in solutions of elastomers aged, than the control. This fact confirms the initial chapeau of physic-chemical interactions of molecules fullerenes by segments of the Kuna and end groups of the polymer chains, as it is known that when thermal-oxidative degradation of rubbers, respectively the number of segments of the Kuna and branched loose ends of macromolecules that are free to react with fullerenes in solution, free from spatial constraints. A comparative analysis of the interaction of rubbers with different chemical composition with double branches has shown that it is easier to just react and has minimum energy polibutadien interaction that has to do with lack of branching and no radicals in its structure and in the backbone chain. The maximum energy of interaction with Fullerenes have SBS rubber because it has large styrene blocks in the main polymer chain that causes the spatial constraints to direct contact with fullerene molecules, you can assume that the interaction is only low-molecular fraction of Fullerenes mixture, possessing the necessary dimensions. As a result of the study shows that the application of the method of separation ring (Du-Nui) allows you to predict the properties of rubber with modified nanomaterial’s with minimal labor costs