With its recent breakthrough in terms of output power, the erbium 3m fiber laser has become an object of intense scientific research and an increasingly attractive tool for medical applications. This paper reviews the research on the erbium 3m fiber laser since its first demonstration. Its development is seen in relationship to the early success of the corresponding crystal laser system, to the...

Classical black holes are solutions of Einstein’s equations of general relativity that exhibit an event horizon. From inside this horizon, nothing (and in particular, no light) can escape. The region inside the horizon is therefore not in the backward lightcone of future timelike infinity. However, since the discovery of Hawking radiation [1], it has become clear that many of the classical feat...

Abstract Nowadays, the development of irrigation is increasingly recognized as a necessary factor in agriculture, primarily because global warming. Depending on field conditions, most commonly used method sprinkler irrigation. The spray uniformity sprinklers installed equipment can be characterized by Christiansen-uniformity coefficient (CUc%) and distribution (DU%). Our investigations were car...

In the structure of the title compound, magnesium hydroxide hydrogenarsenate (6.75/3/4), two different Mg(2+) ions, one located on a site with symmetry 3m. (occupancy 3/4) and one on a general position, as well as two different AsO3(OH) tetra-hedra (symmetry .m. with partial occupancy for the H atom for one, and symmetry 3m. with full occupancy for the H atom for the other) and one OH(-) ion (s...