This communication is a Reply to a Comment on our article ‘On the stability of a bicycle on rollers’. We are glad that our paper Cleary and Mohazzati (2012 Eur. J. Phys. 32 1293) has garnered such vigorous debate and interest. Our paper addresses the stability of a bicycle on rollers as opposed to that on the ground. The authors of the Comment (Dressel and Papadopoulos 2012 Eur. J. Phys. 33 L21...

The quality of earth structures highly depends on the compaction state of fill layers, which can be made up of a wide range of various materials. Compaction is usually accomplished by vibratory rollers; the vibration of the drum is generated by rotating eccentric masses. Moreover, dynamic rollers with different types of excitation have been developed in the last decades, including rollers with ...

Many types of omnidirectional wheels with passive rollers have gaps between rollers. Since these gaps cause a wheel to make discontinuous contact with the ground, they lead to vertical and/or horizontal vibrations during wheel operation. In addition, the radii of passive rollers are related to the height of a bump an omnidirectional wheel can surmount. In this research a new design of the alter...

Chemical defences against predators are widespread in the animal kingdom although have been seldom reported in birds. Here, we investigate the possibility that the orange liquid that nestlings of an insectivorous bird, the Eurasian roller (Coracias garrulus), expel when scared at their nests acts as a chemical defence against predators. We studied the diet of nestling rollers and vomit origin, ...

This article describes a new class of end-effectors that can be used with robotic and material handling devices for grabbing and holding deformable objects with undefined shapes such as sacks and bags. These end-effectors can grab and hold filled sacks from any point on the sack and regardless of the sack orientation and position. The first prototype end-effector, designed for U.S. Postal Servi...

A study was carried out at the Rice Research Institute of Iran (RRII) to investigate the effect of rollers differential peripheral speed of commercial rubber roll husker and paddy moisture content on the husking index and percentage of broken rice. The experiment was conducted at six levels of rollers differential speed (1.5, 2.2, 2.9, 3.6, 4.3 and 5 m/s) and three levels of paddy moisture cont...

There has been a great interest in examining nonlinear effects in the system of rotating magnetic fields. Such effects have been observed in the device called Searl’s generator or SEG (SEG, Searl Effect Generator) [1-4]. An SEG consists of a series of three rings and rollers that go around those rings. All parts of SEG are based on the Law of the Squares. The rollers revolve around the plates t...