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 ...

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...

A modified model has been analytically developed to describe the induction time of an elliptic air bubble in contact with an elliptic hydrophobic oil droplet. The role of hydrophobicity was revealed in the slippage of liquid over the surfaces of bubble and droplet. In this condition, the analytical relationships for pressure distribution and consequently hydrodynamic resistance force through th...

Certain elliptic divisibility sequences are shown to contain only finitely many prime power terms. In some cases the methods prove that only finitely many terms are divisible by a bounded number of distinct primes.

We describe in terms of the j-invariant all elliptic surfaces π : X → C with a section, such that h(X) = rankNS(X) and the Mordell-Weil group of π is finite. We use this to give a complete solution to infinitesimal Torelli for elliptic surfaces over P with a section.

chronic subdural hematoma (csdh) is a curable entity frequently encountered by neurosurgeons. the present study was conducted to explore expert opinion and common practice in iran. besides, a review of randomized clinical trials in literature was performed. a questionnaire including six questions discussing major aspects of practice on csdh, with multiple choices was designed. a pilot study was...

in this paper, we calculate electron and hole impactionization coefficients in in0.52al0.48as using a monte carlo modelwhich has two valleys and two bands for electrons and holesrespectively. also, we calculate multiplication factor for electronand hole initiated multiplication regimes and breakdown voltagein in0.52al0.48as pin avalanche photodiodes. to validate themodel, we compare our simulat...

In the current research work, the problem of fracture mechanics in a plate with a central hole under tensile loading is studied. The stress intensity factors are calculated for a finite plate containing two symmetrical hole-edge cracks. The problem is solved by two different methods, namely the finite element method and the FRANC software analysis. At first the finite element method is used and...