For every point χ in the spectrum of the operator (h(δ)ξ) = ξn+1 + ξn−1 + β ( δe + δe ) ξn on l(Z) there exists a complex number x of modulus one such that the equation ξn+1 + ξn−1 + β ( xδe + xδe ) ξn = χξn has a non-trivial solution satisfying the condition lim |n|→∞ |ξn| 1/|n| ≤ δβ provided that β, δ > 1 and α satisfies the diophantine condition lim n→∞ | sinπαn| 1 n = 1 . The parameters xδ ...

We performed molecular dynamics simulations and theoretical analysis of nanoparticle pulling off from adhesive substrates. Our theoretical model of nanoparticle detachment is based on the Kramers' solution of the stochastic barrier crossing in effective one-dimensional potential well. The activation energy, ΔE, for nanoparticle detachment first decreases linearly with increasing the magnitude o...

PURPOSE This in vitro study evaluated the effects of four different cements on the color attributes of a zirconia ceramic. MATERIALS AND METHODS 40 zirconia ceramic disk specimens (0.5 mm thickness, 10 mm diameter, 0.1 mm cement space) were fabricated by a computer-aided design and computer-aided manufacturing system. The specimens were divided into 4 groups of 10 specimens and cemented to co...

Los granos en zonas altoandinas poseen diversos compuestos nutricionales; no obstante, debido a sus cualidades sensoriales, sólo son consumidos fresco o deshidratados. Una alternativa de procesamiento es el tostado los para la obtención bebidas. El objetivo del estudio fue evaluar tiempo y temperatura sobre solubilidad diferencial color (ΔE) arveja, cebada haba, fin determinar parámetros óptimo...

Fluid-structure interaction problems involving thin-walled membrane and shell-type structures undergoing large deformations can be considered in a step-wise fashion. Using conventional finite elements [1],[6],[8] for the discretization of the fluid or gas domain leads to heavily distorted meshes for the fluid if e.g. inflation or filling processes including large deformations are to be investig...

objectives: masking ability of a restorative material plays a role in hiding colored substructures; however, the masking ability of zirconia ceramic (zrc) has not yet been clearly understood in zirconia-based restorations. this study evaluated the effect of three different core materials on masking ability of a zrc. materials and methods: ten zirconia disc samples, 0.5mm in thickness and 10mm i...

The molecular structures of two Pyridazine derivative;5-phenyl-6-ethyl-pyridazine-3-thione (PEPT) and 5-phenyl-6-ethylpridazine-3-one (PEPO) were simulated for corrosion inhibition efficiency using quantum chemical calculations based on density functional theory (DFT) at the B3LYP/6-31G* basis set level in order to compare relationship between their structure,electronic structure potential.The ...

OBJECTIVES The aim of this study was to evaluate the effect of three different drinks on the color parameters of four different restorative materials. MATERIALS AND METHODS Three different composites (Filtek Ultimate Universal Restorative, Filtek Ultimate Flowable, and Filtek Silorane, 3M ESPE) and a polyacid-modified composite resin material (Dyract XP, Dentsply DeTrey GmbH) were evaluated. ...

OBJECTIVE The aim of this study was to determine the effects of 40% hydrogen peroxide and 15% carbamide peroxide on microhardness and color change of a silorane-based composite resin in comparison with two methacrylate-based composites. MATERIALS AND METHODS Fifty-four disc-shaped specimens (A3 shade) were fabricated of Filtek P90 (P90), Filtek Z350XT Enamel (Z350) and Filtek Z250 (Z250) (3ME...