This study investigates the roles of two distinct features of ionically cross-linked polyelectrolyte networks - ionic cross-links and fixed charges - in determining their nanomechanical properties. The layer-by-layer assembled poly(allylamine hydrochloride)/poly(acrylic acid) (PAH/PAA) network is used as the model material. The densities of ionic cross-links and fixed charges are modulated thro...

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...

importance of covalent bonded two-dimensional monolayer nanostructures and also hydrocarbons is undeniably responsible for creation of new fascinating materials like polyphenylene polymer, a hydrocarbon super honeycomb network, so-called porous graphene. the mechanical properties of porous graphene such as its young’s modulus, poisson’s ratio and the bulk modulus as the determinative properties...

background: characterizing the mechanical properties of brain tissue is deemed important for developing a comprehensive knowledge of the mechanisms underlying brain diseases. mechanical properties of very soft tissues, such as brain until recently have been attracted the attention of researchers because these tissues do not tolerate mechanical loads. the mechanical properties of brain tissue, h...

For dynamic analyses of railway track structures, the algorithm of solution is very important. For estimating the important problems in the railway tracks such as the effects of rail joints, rail supports, rail modeling in the nearness of bridge and other problems, the models of the axially beam model on the elastic foundation can be utilized. For studying the effects of axially beam on the ela...

By means of computer simulations, we study how droplets of hard, rodlike particles optimize their shape and internal structure under the influence of the osmotic compression caused by the presence of spherical particles that act as depletion agents. At sufficiently high osmotic pressures, the rods that make up the drops spontaneously align to turn them into uniaxial nematic liquid-crystalline d...

In the present research, a unified formulation for free vibration analysis of the bidirectional functionally graded conical and cylindrical shells and annular plates on elastic foundations is developed. To cover more individual cases and optimally tailored material properties, the material properties are assumed to vary in both the meridian/radial and transverse directions. The shell/plate is a...

In this study, the effect of edible coat (carboxy methyl cellulose) before osmotic dehydration anddifferent drying methods on sensory and physical properties of dried apple (V. Golden delicious)rings was investigated. The coated and non-coated samples pretreated with 50% sucrose osmoticsolution and dried in freeze drier (-40 to -50°C, 0.026-0.017 mbar, 24 hr), vacuum drier (70°C, 200mbar, 8-10 ...

ABSTRACT: In this study, response surface methodology was used to optimize ultrasound osmotic pretreatment with finished freeze drying of black cherries. Freeze drying is a separation process based on the  sublimation phenomenon. This process has the following advantages as compared to the conventional drying process, maintenance of the structure, moisture removal at low temperature (reduced tr...