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[en] Here, a recent article [McAlister et al., J. Appl. Phys. 122, 144501 (2017)] claims to show the existence of new'' higher order re-entrant post modes. Indeed, such modes do exist and are known to scientists and engineers for a very long time as modes of a foreshortened quarter-wave coaxial resonator. It is a textbook problem. In this comment, I briefly review the higher order modes in such cavities and provide relevant references.
[en] It is offered the new plasmaoptics device that are representing an elementary plasmaoptics cylindrical cell with the gas discharge of magnetron type in a mode of direct magnetron. Such device can work both in a high-voltage low-current mode and in high-current low-voltage with generation of a plasma torch. The measured rate of etching is about 100...150 nm/min in the low-current high-voltage discharge and on the order rises in high-current mode. Density of torch current up to 3% from density of discharge current and the floating potential up to 0,8 from the anode potential are formed.
[en] A new pattern of hollow cathode effect (H.C.E.) in cylindrjcal geometry by using as cathode two coaxial cylinders is presented. The interior electrode was made of wire sieve of 900 holes/cm2. In the cavity of the interior electrode a simple or aided H.C.E. is produced by electronic injection from the external cylinder. In the case of aided H.C.E. the current and radiation amplification are higher thanin the case of the simple one. (author)
[en] This work derives the set of acoustic parameters of a metamaterial for an ideal cylindrical cloak through scattering theory. A multilayered cloak with homogeneous isotropic materials is introduced to approximate the ideal cloak. An active metamaterial, consisting of active arrays of acoustic cavities separated by piezo-diaphragms, is addressed to achieve the required parameters for each layer of the multilayered cloak. In particular, with the aid of a multi-control strategy that takes into account the coupling between adjacent cells, the effective parameters for the cloak can be accurately realized. (paper)
[en] A micro projection lithography process has been implemented using a photomask having arrays of cylindrical or spherical plano-convex microlenses formed by thermal reflow in proximity exposure mode. This approach provides a practical means to generate patterns inside deep cavities without proximity-based pattern size increases. The generated pattern size can be controlled by controlling the focal depth of the microlens. A maximum pattern size reduction of 62% has been achieved at the bottom of a 216 µm deep trench with a cylindrical microlens having a focal length of 254 µm for a 60 µm square pattern. The effect of the microlens on the lithography process, including the relationship between the focal depth, exposure dose and pattern size, has been analyzed. (technical note)
[en] An analytical approach is developed to study the pre- and post-buckling responses of circular cylindrical nanoscale shells subjected to lateral and axial loads as well as thermal environment. The effect of surface free energy as one of the key nanoscale effects is considered in the context of Gurtin-Murdoch surface elasticity theory. The nanoshell is made of functionally graded materials (FGMs) whose properties are calculated using power-law functions. The basic formulation is derived according to the classical shell theory together with the von-Karman nonlinear relations. Moreover, the physical neutral plane position is taken into consideration. Using the Ritz energy method, an analytical approach is also proposed to solve the problem. Comprehensive numerical results are presented to investigate the behavior of nanoshell under lateral pressure and axial load in thermal environment, in pre- and post-buckling domains. The influences of various parameters including the surface stress, FGM gradient index, temperature and geometrical parameters on the non-linear critical axial stress/lateral pressure are illustrated. (paper)
[en] The control rods fastened to the vessel head of a nuclear reactor and which can thus be removed with the head are protected in the removal of the vessel head and its lay-down. For this there is a cylindrical component surrounding the ends of the control rods and jutting out past these which is used as support for the vessel head. The component is fixed to a plate which is held onto a further plate connected with the vessel head by supports where some of the supports are hollow and take up the control rods. The replacement of the vessel head is so designed that fuel element bundles of the reactor core have set pins with conical points for alignment and just into conical counter bores of the plate possessed by the component. Both plates can furthermore be aligned opposite supports of the core support structure. (DG/LH)
[de]Die am Behaelterdeckel eines Kernreaktors befestigten und mit diesem abnehmbaren Steuerstaebe werden bei der Abnahme des Behaelterdeckels und seiner Abstellung geschuetzt. Hierzu dient ein die unteren Enden der Steuerstaebe umgebendes und ueber diese hinausragendes zylindrisches Bauteil, das als Stuetze fuer den Behaelterdeckel benutzt wird. Das Bauteil ist an einer Platte befestigt, die ueber Tragstuetzen an einer weiteren mit dem Behaelterdeckel verbundenen Platte gehalten ist, wobei einige der Tragstuetzen hohl sind und die Steuerstaebe aufnehmen. Fuer das Wiederaufsetzen des Behaelterdeckels ist vorgesehen, dass Brennelementbuendel des Reaktorkernes Passstifte aufweisen, die konische Spitzen besitzen und zur Ausrichtung in konische Gegenbohrungen der Platte hineinragen, die den Bauteil traegt. Beide Platten koennen weiterhin gegenueber Tragstuetzen der Kerntragkonstruktion ausgerichtet werden. (DG)
[en] The gravitational force inside a finite hollow cylinder has been calculated for the Newtonian potential and for a non-Newtonian potential, and the results of other experiments have been reinterpreted in terms of limits on departures from the Newtonian potential. (author)