Electrochemical reduction of the dacarbazine-Cu2+ complex was investigated using cyclic voltammetry and square wave voltammetry at a hanging mercury drop electrode. The reduction of the dacarbazine-Cu2+ complex is irreversible. A reduction mechanism is proposed comprising a one-electron reduction of the Cu2+ directly within the complex. The sharp peak of the adsorbed dacarbazine-Cu2+ complex associated with an effective interfacial accumulation facilitates the determination of the anticancer drug dacarbazine in pharmaceutical formulations and biological fluids. Detection limits for dacarbazine of 6.121010 M, 1.571010 M and 1.97109 M were achieved for the determination of the drug in vial, human urine and serum, respectively.

The effect of temperature on the sequence of hardening precipitates in Al-1·15Mg2Si-0·34Cu-0·21Cr (wt-%) balanced and Al-1·14Mg2Si-0·34Cu-0·21Cr (wt-%) alloys with excess Si has been investigated by hardness measurement (HV), differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) techniques. The values of microhardness which are corresponding to the hardening precipitated particles in the alloy containing excess Si are higher than that in the alloy without Si. The results showed that, the difference in the hardening precipitation peak positions may match the fact that, the excess Si increases the density of β" metastable phase and also, reduces the Mg/Si ratios in the early stage of GP zones and co-cluster formation. After the complete formation of the metastable needle shaped precipitates β" takes place, the strengthening of the alloy would take place as a result of the formation of the semicoherent rod shaped precipitates β' and/or Q' phases.

The thermoelectric power (TEP) and the electrical resistivity (ER) of Al-Mg-Si (balanced) and Al-Mg-Si-Cu (balanced + Cu) alloys have been measured in the temperature range 300-800 K. TEP and ER are found affected by different types of precipitates in the Al matrix. Addition of Cu refined the microstructure of the balanced alloy hence altered the TEP and ER measurements. Cu promotes the kinetics of artificial aging due to the formation of the Q' phase and the intermediate phases which precipitate at earlier temperatures. The coexistence of the equilibrium (3 (Mg2Si) and the stable Q-phases results in stabilization of the TEP at elevated temperatures. The existence of Cu slightly increases the lattice rigidity leading to a decrease in the rate by which the ER increases with temperature. Repeating measurements after slow cooling of the two alloys changed considerably the results of TEP and ER. Correlation was found between different types of precipitates and changes in the TEP and ER indicating the possibility of employing TEP and ER measurements to study the precipitation sequence in such alloys.

The thermoelectric power (TEP) and the electrical resistivity (ER) of Al-Mg-Si (balanced) and Al-Mg-Si-Cu (balanced + Cu) alloys have been measured in the temperature range 300-800 K. TEP and ER are found affected by different types of precipitates in the Al matrix. Addition of Cu refined the microstructure of the balanced alloy hence altered the TEP and ER measurements. Cu promotes the kinetics of artificial aging due to the formation of the Q' phase and the intermediate phases which precipitate at earlier temperatures. The coexistence of the equilibrium (3 (Mg2Si) and the stable Q-phases results in stabilization of the TEP at elevated temperatures. The existence of Cu slightly increases the lattice rigidity leading to a decrease in the rate by which the ER increases with temperature. Repeating measurements after slow cooling of the two alloys changed considerably the results of TEP and ER. Correlation was found between different types of precipitates and changes in the TEP and ER indicating the possibility of employing TEP and ER measurements to study the precipitation sequence in such alloys.