BACKGROUND During orthodontic tooth movement friction occurs at the bracket wire interface. Out of the total force applied to the tooth movement, some of it is dissipated as friction, and the remainder is transferred to the supporting structures of the tooth to mediate tooth movement. However many factors affect friction, and method of arch wire ligation being an important contributing factor. ...

this paper studies thoroughly and deeply the results of about one hundred triaxial compression tests on thirty types of rockfill materials. the materials are categorized in accordance with their particles shape (angular / rounded) and gradation characteristics. the main tool of the study is the hyperbolic model developed by duncan and chang. the focus of the study is on the variations of deform...

Six maxillofacial materials were evaluated by determining their dynamic properties with use of a Goodyear Vibrotester. The dynamic modulus, internal friction, and dynamic resilience were measured for all materials over a temperature range of -15 to 37 C. The dynamic modulus ranged from 11.1 to 124.8 kg/cm2 and the dynamic resilience varied from 1.1 to 63.5%.

Hierarchical structures are very common in nature, but only recently have they been systematically studied in materials science, in order to understand the specific effects they can have on the mechanical properties of various systems. Structural hierarchy provides a way to tune and optimize macroscopic mechanical properties starting from simple base constituents and new materials are nowadays ...

Wear is the progressive loss of material from the operating surface of a body occurring as a result of relative motion at the surface, while friction is the main means of controlling the input of energy in a system. The tribosystem approach proposes analysing the contact on both the material and the energetic planes, but the relationships between the different planes are not well established. I...

We show that the solid-solid friction between bulk chiral molecular solids can depend on the relative chirality of the two materials. In menthol and 1-phenyl-1-butanol, heterochiral friction is smaller than homochiral friction, while in ibuprofen, heterochiral friction is larger. Chiral asymmetries in the coefficient of sliding friction vary with temperature and can be as large as 30%. In the t...