The angular error of indexing table on machine tool is measured using new developed measuring device. The measuring techniques, which have been reviewed in this paper, are currently available in manufacturing engineering to calibrate the angle measurement. The new developed measuring device using 6 points kinematic concept and employing ball and vee grooves is used to calibrate angle errors of ...

In this article, electro-thermo nonlocal nonlinear vibration and instability of viscous-fluid-conveying double–walled boron nitride nanotubes (DWBNNTs) embedded on Pasternak foundation are investigated. The DWBNNT is simulated as a Timoshenko beam (TB) which includes rotary inertia and transverse shear deformation in the formulation. Considering electro-mechanical coupling, the nonlinear govern...

introduction: the aim of the present in vitro study was to evaluate the efficacy of d-race, protaper retreatment kit and hand h-files in removal of obturating materials (om) from the curved root canals using cone-beam computed tomography (cbct). materials and methods: sixty extracted molars were prepared and obturated. the samples were divided into three groups ( n =20). in each group the om wa...

introduction: the aim of this in vitro study was to evaluate the transportation of mesiobuccal canals of mandibular first molars prepared with either biorace or mtwo rotary instruments or hand k-flexofile, by means of cone-beam computed tomography (cbct). methods and materials: forty-five mandibular molars were selected and randomly divided into three groups ( n =15). mesiobuccal roots of these...

This paper investigates the bending vibration of rotating single-walled carbon nanotubes (SWCNTs) based on nonlocal theory. To this end, the rotating SWCNTs system modeled as a beam with a circular cross section and the Euler-Bernoulli beam theory (EBT) is applied with added effects such as rotary inertia, gyroscopic effect and rotor mass unbalance. Using nonlocal theory, two coupled sixth orde...

In this paper, vibration analysis of multiple-stepped Bernoulli-Euler and Timoshenko beams carrying point masses is presented analytically for various boundary conditions. Each attached element is considered to have both translational and rotational inertias. The method of solution is “transfer matrix method” which is based on the changes in the vibration modes at the vicinity of any discontinu...

This paper presents an analytical study on the dynamic stability of carbon nanotubes (CNTs) reinforced functionally graded composite beams when subjected to axial excitation loading. The are using a I-type CNTs reinforcement. section properties non-uniform assessed Halpin–Tsai model. analysis is performed by Bolotin’s method. Analytical expressions determining free vibration frequency, critical...

in order to comparison of weeds mechanical control for sugar beet, a rotary cultivator was designed and constructed in first year, and compared with other mechanical control in second year. five treatments, included: rotary hoe cultivator, furrower cultivator, rotary cultivator, no weeding and manual weeding were compared. experiment design was random complete blocks design (rcbd) with three re...