I n the 1820s Claude Louis Marie Henri Navier1 was a professor at the École des Ponts et Chaussées in Paris, which was the Grande École that trained engineers in nineteenthcentury France. At the same time as publishing his famous fluid equations (now known as the Navier-Stokes equations), he designed the first monumental suspension bridge to be built in Paris over the Seine. His bridge develope...

BACKGROUND Poliomyelitis was before the immunization an important medical problem. Nowadays polio prior patients (PP) suffer from polio sequelae or have developed post-polio-syndrome (PPS) with increasing paresis, pain and fatigue. OBJECTIVES To analyze the medical situation 50 years after acute polio. The degree of paresis was compared between the recovery 1952-1961 and 2012.The prevalence o...

one of the great challenges in the processing of materials using equal channel angular pressing (ecap) is the high forming forces required to produce large shear deformation in the material. researchers show that the friction forces between the die and the sample constitute a great part of the total forming forces. recently, ultrasonic vibrations are successfully implemented into the ecap proce...

The Hungarian mathematician Farkas Bolyai (1775–1856) published in his principal work (‘Tentamen’, 1832–33 [Bol04]) a dense regular packing of equal circles in an equilateral triangle (see Fig. 1). He defined an infinite packing series and investigated the limit of vacuitas (in Latin, the gap in the triangle outside the circles). It is interesting that these packings are not always optimal in s...

It is common among competitive baseball players to swing bats while in the batter's box in an attempt to improve their batting performance. Players use bats of different weights during this time, and only a few studies have evaluated the optimal bat weight to increase performance. Previous studies have not investigated the optimal rest period after a warm-up with bats of varying weights. Theref...

Gait disorders in the elderly are a major cause of falls and accidents. They also interfere badly with the quality of life and the psychosocial well-being. The prevalence of these disorders is very high: 15% of the persons over 65 years and about 25% of those over 75 years suffer from gait disorders. The cause of gait disorders can be a specific disease, but in the elderly, multiple causes are ...