This article describes fretting behavior of zirconia and silicon nitride balls on an electro-deposited coating. Fretting tests are performed using a ball-on-flat configuration. The evolution of the kinetic friction coefficient is determined, along with slip ratio. Experimental results show that the steady-state friction coefficient between ceramic balls (Si₃N₄ and ZrO₂) and an electro-deposited...

Kicking for distance in Australian Rules football is an important skill. Here, I examine technical aspects that contribute to achieving maximal kick distance. Twenty-eight elite players kicked for distance while being videoed at 500 Hz. Two-dimensional digitized data of nine body landmarks and the football were used to calculate kinematic parameters from kicking foot toe-off to the instant befo...

A Q-ball is a stable, charge Q soliton in a scalar field theory with a spontaneously broken global U(1) symmetry . The Q-ball solution arises provided the scalar potential V (φ) is such that V (φ)/|φ|2 has a minimum at non-zero φ. In the MSSM such solitons are necessarily part of the spectrum of the theory, as was first pointed out by Kusenko . This is due to the form of the MSSM scalar potenti...

A Q-ball is a non-topological soliton with some conserved global charge in the scalar field theory [1]. A Qball solution exists if the energy minimum develops at non-zero φ with fixed charge Q. In terms of the effective potential of the field φ, V (φ)/φ take the minimum at φ 6= 0 [1,2]. The Q-ball naturally appears in the spectrum of the Minimal Supersymmetric Standard Model (MSSM) [3]. In part...

In this paper, the performance of the cutting tool with nanocrystalline multilayer coatings (TiN+TiAlN) for machining of superalloy Inconel 718 in the dry and wet conditions was studied. The multi layer TiN and TiAlN with nanocrystalline structure was applied by physical vapor deposition technique (arc evaporation) on the WC-Co inserts. The results of the ball on disc wear test and the machinin...