The present work aims at reducing the friction of rubber soles sliding on ceramic floorings. Fitting bored cylindrical protrusions with different diameters on rubber soles was proposed. Experiments were carried out to evaluate the performance of the proposed protrusions in increasing friction coefficient at dry and contaminated floorings. It was found that, at dry sliding, friction coefficient ...

In a large class of string and string inspired models the string excitation and black hole pictures invoked as an explanation of trans-GZK cosmic ray events are equivalent. Single particle inclusive distributions are asymptotically thermal at the Hagedorn temperature. The hadron multiplicities are reminiscent of multiplicities in heavy nucleus initiated interactions.

many experimental studies have been conducted on development of the scour hole as a result of vertical jet impaction. research has shown that aeration of the nappe flow in the model is much weaker than that in the prototype. therefore, the influence of aeration on scour holes needs further study. experimental investigation of the effects of air entrainment and tail water depth on the scour hole...

We present a unified semi-quantitative model for the disc-jet coupling in black hole X-ray binary systems. In the process we have compiled observational aspects from the existing literature, as well as performing new analyses. We argue that during the rising phase of a black hole transient outburst the steady jet known to be associated with the canonical ’low/hard’ state persists while the X-ra...

We consider the space-time associated with the evaporation of a black hole by quantum mechanical tunnelling events. It is shown that the surface through which tunnelling occurs is distinct from the global event horizon, and that this has consequences for the radiation reaching future null infinity.

Identifying the properties of the first generation of seeds of massive black holes is key to understanding the merger history and growth of galaxies. Mergers between ∼ 100M seed black holes generate gravitational waves in the 0.1–10Hz band that lies between the sensitivity bands of existing ground-based detectors and the planned space-based gravitational wave detector, the Laser Interferometer ...

Aims. We study the probability of close encounters between stars from a nuclear cluster and a massive black hole (104 M⊙ . M• . 108 M⊙). The gravitational field of the system is dominated by the black hole in its sphere of influence. It is further modified by the cluster mean field (a spherical term) and a gaseous disc/torus (an axially symmetric term) causing a secular evolution of stellar orb...