A Power-Supply Unit for Pulsed Lasers without a Storage Capacitor

A power-supply unit for pulsed lasers that are pumped by low- and medium-power flashlamps with long pump pulses that does not require a capacitive storage unit is described. The pump-pulse duration is limited by the radiation and thermal stability of the active elements and pump lamps. A functional diagram of the power-supply unit and a circuit diagram of its power system are presented. The basic parameters and elements of this unit, as well as the results of using a laser with the described power supply in experiments, are presented.     

Nickel versus cobalt catalysts for hydrogen production by ethanol steam reforming: Ni–Co–Zn–Al catalysts from hydrotalcite-like precursors

The urea hydrolysis method allowed to prepare well-crystallized Ni–Co–Zn–Al Layered Double Hydroxides to be used as precursors of mixed oxide catalysts for the Ethanol Steam Reforming (ESR) reaction. The calcination of the layered precursors gives rise to high surface area mixed oxides, being actually a mixture of a rock salt phase (NiO), a wurtzite phase (ZnO) and a spinel phase.     

Relation Between the North-Atlantic Oscillation and Hydroclimatic Conditions in Mediterranean Areas

Mediterranean basins are known for their susceptibility to water stress conditions resulting from a reduction in winter-season precipitation. This region is also prone to the effects of the North Atlantic Oscillation (NAO), a large-scale climatic pattern associated with a displacement of air mass between the arctic and the subtropical Atlantic. Even though previous studies have demonstrated the impact of the NAO on winter climate conditions in Europe and Northern Africa, it is still unclear to what extent the NAO is related to hydroclimatic patterns in Mediterranean areas and whether it can explain its recent drought history. To this end, this study investigates the interdependence between the NAO and winter precipitation, river flow and temperature in two Mediterranean regions: Southern Italy and Nile Delta (Egypt). The outcomes show the presence of significant connections between the NAO, winter rainfall and river discharge.