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...

An analytical model of the electrostatic force between the tip of a non-contact Atomic Force Microscope (nc-AFM) and the (001) surface of an ionic crystal is reported. The model is able to account for the atomic contrast of the local contact potential difference (CPD) observed while nc-AFM-based Kelvin Probe Force Microscopy (KPFM) experiments. With the goal in mind to put in evidence this shor...

An in vitro model was used to test a hypothesis that the manual (apex locator) and motor-driven (apex locator-controlled handpiece) operating modes of 3 newly developed apex-locator-controlled handpiece devices (Dentaport ZX, Endomaster, XSmart Dual) give the same working length. The depth of penetration of the file into the root canal was measured using a digital micrometer and the distance of...

OBJECTIVES To compare, in vivo, the accuracy of conventional and digital radiographic methods in determining root canal working length. MATERIAL AND METHODS Twenty-five maxillary incisor or canine teeth from 22 patients were used in this study. Considering the preoperative radiographs as the baseline, a 25 K file was inserted into the root canal to the point where the Root ZX electronic apex ...

A study of single-tip tungsten emitters with the construction current–voltage dependences in quadratic Fowler–Nordheim coordinates and modified (Murphy–Good plot that depend on value work function) real-time has been carried out. The statistical data emission area field enhancement factor were accumulated. voltage power pre-exponential obtained by plotting dependence notional dimensionless at t...

Tip-enhanced Raman spectroscopy (TERS) is based on the optical excitation of localized surface plasmons in the tip-substrate cavity, which provides a large but local field enhancement near the tip apex. We report on TERS with smooth single crystalline surfaces as substrates. The adsorbates were CN- ions at Au(111) and malachite green isothiocyanate (MGITC) molecules at Au(111) and Pt(110) using...

background: management of canal isthmus is considered as an important factor for successful endodontic treatment. accordingly, this study was designed to determine the prevalence, location, and types of isthmus in mesial root canals of extracted mandibular molars in a sample of iranian population. materials and methods: in this cross-sectional descriptive study, 60 extracted molars with two mes...

When an external laser illuminates a nanoscale tip, heating effect arises from absorption of light. This thermal phenomenon happens in near-field scanning optical microscopy (NSOM), 5 apertureless NSOM, tip-enhanced Raman spectroscopy (TERS), laser-assisted scanning tunneling microscope (STM)/ atomic force microscope (AFM)-assisted surface modification and nanofabrication, 11 and high density d...