Bubble performance of a novel dissolved air flotation(DAF) unit

ES-DAF, a novel DAF with low cost, high reliability and easy controllability, was studied. Without a costly air saturator, ES-DAF consists of an ejector and a static mixer between the pressure side and suction side of the recycle rotary pump. The bubble size distribution in this novel unit was studied in detail by using a newly developed CCD imagination through a microscope. Compared with M-DAF under the same saturation pressure, ES-DAF can produce smaller bubble size and higher bubble volume concentration, especially in lower pressure. In addition, the bubble size decreases with the increase of reflux ratio or decrease of superficial air-water ratio. These results suggested that smaller bubbles will be formed when the initial number of nucleation sites increases by enhancing the turbulence intensity in the saturation system.

Water Production by Condensation of Wet Air

It is now assumed that climate warming is effective and noticeable. It not only leads to a lack of water that is increasing in desert areas, but it must be kept in mind that the inhabitants of the villages located in the geographical areas whose access to water is difficult, make binding efforts to gain access to water. This article proposes to present the possibility of obtaining water by the condensation of the water vapors of the air by applying the thermodynamic processes of the humid air as well as those of the refrigerating installations. In fact, atmospheric air contains suspended water vapors. When this steam cools below its rose point, there is condensation if water vapors and liquid water or ice appears. It was obtained a quantity of condensed vapors in a refrigeration facility. This amount is directly proportional to the refrigeration power whose efficiency can be improved by the use of photovoltaic energy given the reduced financial cost of this energy. This seems to be a hope among the possible solutions to be considered for the resolution of the water issue.

Air stable Fe nanostructures with high magnetization prepared by reductive annealing

Monodispersed Fe nanospindles and nanoparticles were successfully synthesized through environmentfriendly reductive annealing ？-Fe OOH nanorods. Effects of annealing temperature and reaction atmosphere on microstructure, phase, and magnetic property of Fe nanostructures were investigated.The as-obtained pure Fe nanoparticles with mean size of 45 nm had a high saturation magnetization up to 207 emu/g, close to that of bulk material（218 emu/g）, which exhibited high air stability. After exposing in air for 2 and 7 days, the as synthesized Fe nanoparticles still showed high magnetization of 182 and141 emu/g, respectively.