Amorphous packings of frictionless, spherical particles are isostatic at jamming onset, with the number of constraints (contacts) equal to the number of degrees of freedom. Their structural and mechanical properties are controlled by the interparticle contact network. In contrast, amorphous packings of frictional particles are typically hyperstatic at jamming onset. We perform extensive numeric...

The aim of this in vitro study was to investigate the frictional characteristics of two types of self-ligating brackets ('A' Company Damon SL and Adenta Time brackets) and two types of pre-adjusted edgewise brackets (TP Tip-Edge and 'A' Company Standard Twin brackets). The test brackets were glued to steel bars and aligned using a preformed jig. Five combinations of archwire size and material w...

In the present paper the pressure drop characteristics of a 1.4 mm hydraulic diameter multiport minichannel tube during adiabatic two-phase flow of HFC refrigerants are discussed. The tube consists of eleven parallel rectangular cross section channels. Although much experimental research has been devoted to investigate the pressure drop characteristics of R134a inside multiport minichannels in ...

Dense phase pneumatic conveying is widely used to transport granular materials or powder due to its efficiencies gained on cost and abrasion and erosion. To date these systems have been designed and analyzed using average frictional representation for the conveyed plug. This study explores the effect of this friction force by measuring strains on the pipe wall when the plug is moving passed the...