This paper describes some computer simulations of the breakage induced in a two-dimensional particle bed by the descent of a single Ž large grinding ball. These are approximate experiments related to ball-milling that are tractable by the simulation technique i.e., involve . relatively few particles . As a result of the impact of the grinding ball, the particles in the bed are broken andror sca...

The paper presents application of an e nergy-based finite e lement and a local rel axation method to computer calculation of deformation of a ring made of hyperelastic material. T he present study consi ders a surface friction mechanism. This mechanism is a physical phenomenon counteracting the relative motion of the c ontacting bodies. Friction causes loss of e nergy the dissipation of which i...

Objectives The friction between the brackets and orthodontic wire during sliding mechanics inflicts difficulties such as decreasing the applied force and tooth movement and also the loss of anchorage. Therefore, many studies have focused on the factors that affect the friction. The purpose of this study was to assess the effect of 0.05% sodium fluoride mouthwash on the friction between orthodon...

We report on the effects of an electrical charge on mechanical loss of a fused silica disk. A degradation of Q was seen that correlated with charge on the surface of the sample. We examine a number of models for charge damping, including eddy current damping and loss due to polarization. We conclude that rubbing friction between the sample and a piece of dust attracted by the charged sample is ...

We propose that stress can decrease the internal friction of amorphous solids, either by increasing the potential barriers of defects, thus reducing their tunneling and thermal activation that produce loss, or by decreasing the coupling between defects and phonons. This stress can be from impurities, atomic bonding constraints, or externally applied stress. Externally applied stress also reduce...

One of the great enemies of rubber compounds is heat. Heat will cause chemical and physical degradation of vulcanized rubber as well as a considerable loss in its strength. A major source of heat generation in a tire is due to internal friction resulting from the viscoelastic deformation of the tire as it rolls along the road. Another source of heat generation in a tire is due to its contact fr...

Following a recession, the aggregate labor market is slack—employment remains below normal and recruiting efforts of employers, as measured by vacancies, are low. A model of matching frictions explains the qualitative responses of the labor market to adverse shocks, but requires implausibly large shocks to account for the magnitude of observed fluctuations. The incorporation of wage-setting fri...

Following a recession, the aggregate labor market is slack–employment remains below normal and recruiting efforts of employers, as measured by help-wanted advertising and vacancies, are low. A model of matching friction explains the qualitative responses of the labor market to adverse shocks, but requires implausibly large shocks to account for the magnitude of observed fluctuations. The incorp...

It is hard to define aspiration noise phenomenally. Although it occurs as a “part of a voiced sound such as vowels” (Kob 2002), a distinction is made as a contrary to friction that happens on the vocal path and leads to fricative consonants (Jackson 2000). The characteristic of aspiration noise, as denoted by Jackson (2000), is broadband, with an hlike sound. It is, being more physically reveal...