Podczas trwających już czwarty rok polskich prac ratowniczych w rejonie IV katarakty Nilu archeolodzy odkryli i zbadali wiele fascynujących zabytków nubijskiej kultury. Na ich podstawie zrekonstruowali obfitującą w dramatyczne wydarzenia historię tych terenów.

In four years of salvage work in the region of the Fourth Nile Cataract, Polish archeologists have discovered and studied many artifacts of the Nubian culture. These objects have enabled them to reconstruct the history of these territories abounding in dramatic events.

We describe an all−in−fibre apparatus for Constant Intensity Direct Absorption Spectroscopy (CIDAS) for gas concentration measurements which keeps the power of a diode laser constant along the frequency sweep. The reduction of the large variation of the laser power, connected to the frequency scan, enhances the ability of detecting small variations in a background signal, resulting in an increase of the sensitivity with respect to standard direct absorption techniques. Moreover, CIDAS allows for a real−time observation of the absorption signals without any kind of post−detection processing. The apparatus has been tested with carbon dioxide (CO₂) and methane (CH₄), around 1.57 and 1.65 μm, respectively.