586 research outputs found

    Small turbing-type flowmeters for liquid hydrogen

    Get PDF
    Characteristics of turbine-type flowmeters in two sizes and with various types of bearings are presented. Calibration procedures of instruments are described. Accuracies obtainable under various conditions are analyzed

    Life tests of small turbine-type flowmeters in liquid hydrogen

    Get PDF
    A total of 14 turbine-type flowmeters of 2.5- and 4-cm nominal size were operated for 100 or more hours at an average fluid speed in the unobstructed, upstream pipe of 20 m/s for the smaller meters and 9 m/s for the larger meters. Calibration shifts over a 6.1 range of calibration flow rates varied from 0.5 percent to 1 percent after 50 hr of operation. It is concluded that use of ball bearings with glass-filled Teflon retainers is most likely to produce minimal calibration shift with protracted use. Bearing replacement after 50 to 100 hr is recommended, depending on accuracy requirements, for meters used at the fluid speeds of the tests

    Theoretical Prediction for Synthetic Realization: Pyramidal Systems ClE[E′4R4] (E = B–Ga, E′ = C–Ge, R = SiMe3, SiMetBu2): A DFT Study

    Get PDF
    Structure and bonding of hybrid group 13/14 pyramidal molecules ClE[R4] (E = B–Ga, E′ = C–Ge, R = SiMe3, SiMetBu2) were studied by DFT calculations. Six pyramidal structures are suggested for their potential synthetic realization

    Hydrodynamics of polar liquid crystals

    Full text link
    Starting from a microscopic definition of an alignment vector proportional to the polarization, we discuss the hydrodynamics of polar liquid crystals with local C∞vC_{\infty v}-symmetry. The free energy for polar liquid crystals differs from that of nematic liquid crystals (D∞hD_{\infty h}) in that it contains terms violating the n→−n{\bf{n}}\to -{\bf{n}} symmetry. First we show that these Z2\mathcal{Z}_2-odd terms induce a general splay instability of a uniform polarized state in a range of parameters. Next we use the general Poisson-bracket formalism to derive the hydrodynamic equations of the system in the polarized state. The structure of the linear hydrodynamic modes confirms the existence of the splay instability.Comment: 9 pages, corrected typos, added references, revised content, to appear in PR

    Commercially available diagnostic device use in educational process: Experience and innovation

    Get PDF
    The publication material discloses the use of the methodology of psychopedagogical diagnostics in working with children and students of different age groups, organized under the leadership of the school psychologist, social educator, school or university teacher or students in Elabuga educational institutions of the Republic of Tatarstan. Here an analysis of the experience of the diagnostic and commercially available device use by the teachers and students of Elabuga Institute of Kazan Federal University (EI KFU) is described, in particular: "Activation meter - AC-9k", "Comfort LOGO", "Personality factor questionnaire (diagnosis of personality traits according to the procedure designed by P. Cattell)". Particular attention is paid to the organization of work with children in the mode of "a fairy-tale therapy": - "Lord of Wonderland", "Island of Childhood" and some other activities. A technology of modified diagnostic children's games (children's game kits) development is proposed as an innovative direction in commercially available diagnostic device use in school and university educational work. The article describes ways to design children's game kits, the techniques and methodology of their use in working with students in schools, additional educational institutions, as well as in the classroom at the children's camp "Intel Summer" and teenage associations "Junior Programmer" and "Young Physicist". According to the authors, the development of commercially available diagnostic children's game kits, as well as their use contribute to professional and creative development of all the members of educational process

    Experimental Designs for Binary Data in Switching Measurements on Superconducting Josephson Junctions

    Full text link
    We study the optimal design of switching measurements of small Josephson junction circuits which operate in the macroscopic quantum tunnelling regime. Starting from the D-optimality criterion we derive the optimal design for the estimation of the unknown parameters of the underlying Gumbel type distribution. As a practical method for the measurements, we propose a sequential design that combines heuristic search for initial estimates and maximum likelihood estimation. The presented design has immediate applications in the area of superconducting electronics implying faster data acquisition. The presented experimental results confirm the usefulness of the method. KEY WORDS: optimal design, D-optimality, logistic regression, complementary log-log link, quantum physics, escape measurement

    Elbow

    Get PDF
    The Elbow, the part of the human body that a blind or partially sighted person takes hold of, four fingers on the inside, thumb on the outside; holding with a firm grip to assist them with navigation. It is a common guiding technique linking two people into an unfamiliar choreography. In the summer of 2015 C&C Gallery hosted an innovative residency programme, transforming the gallery space into a dynamic studio environment in order to respond to ideas surrounding the condition of blindness. During this time eight artists variously came and went, engaging with a whole repertoire of processes, from casting to laser scanning, leaving a variety of traces of their activities. Much of the work, arrived at through a collaborative approach has sought to obliquely cast a shadow across the subject, remaining open towards the process of making, and the work remains in a state of uncertainty even at the time of writing. During a workshop in the space hosted by John Dickinson-Lilley, the artists wore blind glasses and stumbled rather pathetically around the gallery and the local high street, feeling unsure, insecure and inept, grounded only by the feeling of the floor beneath ones feet and ones fingers upon a companions elbow. Within the space; chalk lines, floor to ceiling columns and laser scanning targets have created an installation for measurement, where diverse material usage- including borax, expanding foam and cat litter humorously confound expectation

    Photoinitiated azo-hydrazo tautomerizm of 1- p

    Get PDF
    A novel photochromic compound with NH-N intramolecular H-bond (1-p-toluenesulphonylazo- 2,4,6,8-tetrakis(tert-butyl)phenoxazine) and the corresponding model structures (1-oxo-2,4,6,8-tetrakis(tertbutyl) phenoxazine, 2,4,5,7-tetrakis (tert-butyl )-1-( veratroylazo ) phenoxazine, 2,4,5,7-tetrakis ( tert-butyl )-Nacetyl- 1-(p-toluenesulphonylazo)phenoxazine) have been synthesized and their spectral and photochemical properties are studied. The photochromic transformations observed are found to be conditioned by ESIPT (as a primary step) followed by E-Z isomerisation about N–N-bond

    Acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-Ones: Molecular Switches with Varying Migrants and Substituents

    Get PDF
    Synthesis and properties of photochromic acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-ones are described. Their structure largely depends on the nature of acyl migrant and in a less degree on N-aryl substituent
    • …
    corecore