background: the aim of this study was to compare the effects of conventional acid etching and laser etching on the nano-mechanical properties of the dental enamel using nano-indentation test. materials and methods: in this experimental in vitro study, buccal surfaces of 10 premolars were divided into three regions. one of the regions was etched with 37% phosphoric acid and another etched with e...

Free vibration characteristics of continuous grading fiber orientation (CGFO) beams resting on variable Winkler and two-parameter elastic foundations have been studied. The beam is under different boundary conditions and assumed to have arbitrary variations of fiber orientation in the thickness direction. The governing differential equations for beam vibration are being solved using Generalized...

despite its numerous potential applications, two-dimensional monolayer graphyne, a novel form of carbon allotropes with sp and sp2 carbon atoms, has received little attention so far, perhaps as a result of its unknown properties. especially, determination of the exact values of its elastic properties can pave the way for future studies on this nanostructure. hence, this article describes a dens...

BACKGROUND Carotid intima media thickness (CIMT) and the presence of carotid plaque have been used for risk stratification of cardiovascular disease (CVD). To date, however, the association between multi-directional functional properties of carotid artery and CVD has not been fully elucidated. We sought to explore the multi-directional mechanics of the carotid artery in relation to cardiovascul...

Antler and limb bone have a similar microstructure and chemical composition. Both are primarily composed of type I collagen and a mineral phase (carbonated apatite), arranged in osteons in compact (cortical bone) sections and a lamellar structure in the cancellous (spongy or trabecular bone) sections. The mineral content is lower in antler bone and it has a core of cancellous bone surrounded by...

First principles calculations are preformed to systematically investigate the elastic and thermodynamic properties of Re2N at high pressure and high temperature. The Re2N exhibits a clear elastic anisotropy and the elastic constants C11 and C33 vary rapidly in comparison with the variations in C12, C13 and C44 at high pressure. In addition, bulk modulus B, elastic modulus E, and shear modulus G...

The mechanical properties of in situ composites based on blends of polycarbonate and a liquid crystalline copoly(ester amide) (Vectra B950) have been studied as functions of the liquid crystalline polymer (LCP) concentration and the draw ratio, a processing parameter. It is shown that both the elastic modulus and the tensile strength of the in situ composites increase steadily with the LCP conc...

In this research, the influence of adding micro- and nano- sized calcium carbonate powders to nylon-66 was investigated. Mechanical properties of micro and nano- composites, including tensile strength, elongation, and Young’s modulus, before and after ageing, were determined and analyzed. For this purpose, micro- and nano-sized CaCO3 particles were used as fillers to prepare micro-composites (c...

OBJECTIVES/HYPOTHESIS The trachea is essential to respiratory function and is a mechanically and biochemically complex composite tissue. Tissue-engineering approaches to treat tracheal diseases require detailed knowledge of the native mechanical and biochemical properties of the trachea. Although the porcine trachea represents an excellent preclinical model, relevant mechanical and biochemical ...