Carbon - containing covering for anchoring breaking nematic microdevices

We demonstrate experimentally, that inresidual atmosphere of scanning electron microscope the nano-scale carbon-containing (hydrocarbon) films by snuff effect can be produced. The micropattern of carbon film including axial-symmetric ones is defined by the e-beam rasteryesBelgorod State Universit

Rotor profile design and numerical analysis of 2–3 type multiphase twin-screw pumps

Increasing demands for high-performance handling of fluids in oil and gas as well as other applications require improvements of efficiency and reliability of screw pumps. Rotor profile plays the key role in the performance of such machines. This paper analyses difference in performance of 2–3 lobe combination of twin-screw pumps with different rotor profiles. A-type profile formed of involute–cycloid curves and D-type formed of cycloid curves are typical representatives for 2–3 type screw pumps. The investigation is performed by use of a full 3-D computational fluid dynamics analysis based on a single-domain structured moving mesh obtained by novel grid generation procedure. The real-time mass flow rate, rotor torque, pressure distribution and velocity field were obtained from 3D computational fluid dynamics calculations. The performance curves were produced for variable rotation speeds and variable discharge pressures. The computational fluid dynamics model was validated by comparing the simulation results of the A-type pump with the experimental data. In order to get the performance characteristics of D-type profile, two rotors with D-type profile were designed. The first has the same displacement volume as A-type while the second has the same lead and rotor length as A-type but different displacement volume. The comparison of results obtained with two rotor profiles gave an insight on the advantages and disadvantages of each of them

Language Choice and Identity of Karelian and Belarusian Youth (according to Polls of Ethnic Leaders)

A new perspective on the analysis of the linguistic and ethnocultural situation in the Republic of Karelia and the Republic of Belarus is offered in the study. The novelty of the study is seen in the fact that, taking into account various initial parameters — geographic distance, form of government, language status — it is proposed to compare the situation in two regions, in which a general tendency is found due to the dominant position of the Russian language. The main attention is paid to clarifying the ethnic well-being of people, to varying degrees, involved in the processes of preserving language and culture. An interpretation and comparison of the reasons for the preference of the Russian language in the network space and in real life is proposed. The article is based on the results of a survey of the translators of the Vkontakte social network interface, materials from biographical interviews with ethnic leaders, and observation data on ethnically oriented events in the regions under consideration. The difference in linguistic attitudes and real practices of using the Karelian and Belarusian languages by activists was revealed. The linguistic reasons (the level of linguistic competence) and the psychological aspect of the ethno-linguistic component in the choice of the dominant language in Karelia and Belarus have been determined

ART-XC: A Medium-energy X-ray Telescope System for the Spectrum-R-Gamma Mission

The ART-XC instrument is an X-ray grazing-incidence telescope system in an ABRIXAS-type optical configuration optimized for the survey observational mode of the Spectrum-RG astrophysical mission which is scheduled to be launched in 2011. ART-XC has two units, each equipped with four identical X-ray multi-shell mirror modules. The optical axes of the individual mirror modules are not parallel but are separated by several degrees to permit the four modules to share a single CCD focal plane detector, 1/4 of the area each. The 450-micron-thick pnCCD (similar to the adjacent eROSITA telescope detector) will allow detection of X-ray photons up to 15 keV. The field of view of the individual mirror module is about 18 x 18 arcminutes(exp 2) and the sensitivity of the ART-XC system for 4 years of survey will be better than 10(exp -12) erg s(exp -1) cm(exp -2) over the 4-12 keV energy band. This will allow the ART-XC instrument to discover several thousand new AGNs

Transverse magnetic routing of light emission in hybrid plasmonic-semiconductor nanostructures: Towards operation at room temperature

We study experimentally and theoretically the temperature dependence of transverse magnetic routing of light emission from hybrid plasmonic-semiconductor quantum well structures where the exciton emission from the quantum well is routed into surface plasmon polaritons propagating along a nearby semiconductor-metal interface. In II-VI and III-V direct band semiconductors the magnitude of routing is governed by the circular polarization of exciton optical transitions, that is induced by a magnetic field. For structures comprising a (Cd,Mn)Te/(Cd,Mg)Te diluted magnetic semiconductor quantum well we observe a strong directionality of the emission up to 15% at low temperature of 20 K and magnetic field of 485 mT due to giant Zeeman splitting of holes mediated via the strong exchange interaction with Mn$^{2+}$ ions. For increasing temperatures towards room-temperature the magnetic susceptibility decreases and the directionality strongly decreases to 4% at T = 45 K. We also propose an alternative design based on a non-magnetic (In,Ga)As/(In,Al)As quantum well structure, suitable for higher temperatures. According to our calculations, such structure can demonstrate emission directionality up to 5% for temperatures below 200 K and moderate magnetic fields of 1 T.Comment: 15 pages, 10 figure

Higgs Bosons Production with Photons at Lepton-Antilepton Colliders

By model independent way scalar and pseudoscalar neutral Higgs boson production with photon in the tree process $\mu^+\mu^- \to H^0 \gamma$ are considered.For the Standard Model and Minimal Supersymmetric Standard Model cases numerical estimates are obtained.The model independent flavour changing Higgs bosons production in the tree processes $e^+e^-,\mu^+e^- \to H^0_{fc} \gamma$ is also considered.Comment: 12 pages, LaTeX file, using eps.sty, 4 ps figures include

New Symmetries in Crystals and Handed Structures

For over a century, the structure of materials has been described by a combination of rotations, rotation-inversions and translational symmetries. By recognizing the reversal of static structural rotations between clockwise and counterclockwise directions as a distinct symmetry operation, here we show that there are many more structural symmetries than are currently recognized in right- or left-handed handed helices, spirals, and in antidistorted structures composed equally of rotations of both handedness. For example, though a helix or spiral cannot possess conventional mirror or inversion symmetries, they can possess them in combination with the rotation reversal symmetry. Similarly, we show that many antidistorted perovskites possess twice the number of symmetry elements as conventionally identified. These new symmetries predict new forms for "roto" properties that relate to static rotations, such as rotoelectricity, piezorotation, and rotomagnetism. They also enable symmetry-based search for new phenomena, such as multiferroicity involving a coupling of spins, electric polarization and static rotations. This work is relevant to structure-property relationships in all material structures with static rotations such as minerals, polymers, proteins, and engineered structures.Comment: 15 Pages, 4 figures, 3 Tables; Fig. 2b has error

Electron Field Emission from Undoped and Doped DLC Films

Electron field emission and electrical conductivity of undoped and nitrogen doped DLC films have been investigated. The films were grown by the PE CVD method from CH{sub 4}:H{sub 2} and CH{sub 4}:H{sub 2}:N{sub 2} gas mixtures, respectively. By varying nitrogen content in the gas mixture over the range 0 to 45%, corresponding concentrations of 0 to 8 % (atomic) could be achieved in the films. Three different gas pressures were used in the deposition chamber: 0.2, 0.6 and 0.8 Torr. Emission current measurements were performed at approximately 10{sup -6} Torr using the diode method with emitter-anode spacing set at 20 {micro}m. The current - voltage characteristics of the Si field electron emission arrays covered with DLC films show that threshold voltage (V{sub th}) varies in a complex manner with nitrogen content. As a function of nitrogen content, V{sub th} initially increases rapidly, then decreases and finally increases again for the highest concentration. Corresponding Fowler-Nordheim (F-N) plots follow F-N tunneling over a wide range. The F-N plots were used for determination of the work function, threshold voltage, field enhancement factor and effective emission area. For a qualitative explanation of experimental results, we treat the DLC film as a diamond-like (sp{sup 3} bonded) matrix with graphite-like inclusions