field ion microscopy (fim) and scanning tunneling microscopy (stm) have found a wide application in nanotechnology. these microscopes use a metallic nanotip for image acquisition. resolution of fim and stm images depends largely on the radius of nanotip apex; the smaller the radius the higher the resolution. in this research, for tungsten nanotip fabrication, electrochemical etching of tungsten...

Frame stability in Ilizarov external fixators is mainly dependent on the tension of the transosseous wires, which are clamped to the ring by connection bolts. It was the purpose of this biomechanical study to investigate the holding capacity of a modified bolt design featuring a ruffled wire-bolt interface (TrueLok™) and its influence on wire stiffness in comparison with that of classic bolts f...

Background: Wire Electrical discharge machining (WEDM) has higher capability for cutting complex shapes with high precision for very hard materials without using high cost of cutting tools. During the WEDM process, the wire behaves like a metal string, straightened by two axial pulling forces and deformed laterally by a sum of forces from the discharge process. Major forces acting on the wire c...

objectives: the aim of this study was to assess and compare the characteristics of commonly used initial archwires by their load deflection graphs. materials and methods : this study tested three wire designs namely copper nickel titanium (cnt), nickel titanium (niti), and multi-strand niti (msnt) archwires engaged in passive self-ligating (psl) brackets, active self-ligating (asl) brackets or ...

BACKGROUND The initial arch wire is the first arch wire to be inserted into the fixed appliance at the beginning of orthodontic treatment and is used mainly for correcting crowding and rotations of teeth. With a number of orthodontic arch wires available for initial tooth alignment, it is important to understand which wire is most efficient, as well as which wires cause the least amount of root...

A noninteracting quantum-dot arrays side coupled to a quantum wire is studied. Transport through the quantum wire is investigated by using a noninteracting Anderson tunneling Hamiltonian. The conductance at zero temperature develops an oscillating band with resonances and antiresonances due to constructive and destructive interference in the ballistic channel, respectively. Moreover, we have fo...

In this paper, stiffness of planar translational wire-actuated parallel manipulators is studied. The complete form of the stiffness matrix of the two degrees of freedom manipulators is formulated parametrically. The differential form of the static force balance equations is used to incorporate the variation of wire stiffness with wire length and the change in the Jacobian matrix under external ...

In order to apply Ni-Ti superelastic alloy to wire clasp in dentistry, the bending characteristics and the shape memory treatment of the wire were investigated. The wire cooled in iced water was more easily bent than that stored at room temperature . In both conditions, however, most of the wire specimens were broken by bending before the radius of curvature became less than three times the dia...

An online tail breaking force measurement method is developed with a proximity sensor between wire clamp and horn. The wire under the tensile load measures about 1.5 cm extending from the bond location to the wire clamp. To increase the sensitivity, the bondhead speed is reduced to 2mm/s during breaking the tail bond. It takes roughly 10ms to break the tail bond. The force resolution of the met...

The current specifications governing the construction of wire rope and the fabrication of the assemblies used in movable bridges are no longer the best or most reasonable choice for wire rope selection. The current AASHTO and AREMA specifications for wire rope list “6x19 class improved plow steel wire rope of 6x25 filler wire construction with hard fiber core” as the construction for both opera...