Investigation of mechanism and critical parameters for removal of arsenic from water using Zr-TiO2 composite.

Using the microwave-hydrothermal method for the synthesis of composite, high surface density of hydroxyl groups, as an active adsorption sites for arsenic, was obtained. Adsorption mechanisms of As(III) and As(V) onto zirconium-doped titanium dioxide (Zr-TiO2) were investigated and proposed using macroscopic and microscopic methods. Obtained results are suggesting inner-sphere and outer-sphere adsorption mechanisms for As(III) and As(V), respectively. This allowed us to identify parameters that are critical for the successful removal of arsenic from water, which is essential information for further optimization of the removal process. The composite was further applied for the removal of As(III) and As(V) from water in a dynamic flow through the reactor. Column study proved that the removal of both arsenic species below the value recommended by WHO can be achieved. Elution of As(III) and As(V) from the composite can be done by using small amounts of 0.01 M NaOH solution resulting in preconcentration of arsenic species and possible multiple usage of composite.

Dynamic analysis of the three-phasic vascular response to histamine in coronary circulation.

In this work we tried to perform a dynamic analysis of coronary vascular response to histamine, using a simple mathematical analysis as a first step in the better understanding of complex histamine effects on coronary blood vessels of the isolated guinea pig heart. So, we defined more parameters, such as: I and delta I to quantify the intensity of coronary perfusion pressure (CPP) change, T and dt to quantify the time CPP change occurs and D to characterize the intensity and duration of CPP change, i.e. to quantify the dynamics of this change.