Current efficiency in the chlorate cell process

A mathematical model has been set up for current efficiency in a chlorate cell acting as an ideal electrochemical tubular reactor with a linear increase in hypochlorite concentration from the entrance to the exit. Good agreement was found between the results on current efficiency experimentally obtained under simulated industrial chlorate production conditions and the theoretical values provided by the mathematical model. © 2014 SCS. All rights reserved

Effect of milling and annealing on microstructural, electrical and magnetic properties of electrodeposited Ni-11.3fe-1.4W alloy

A nanostructured Ni-11.3Fe-1.4W alloy deposit was obtained from an ammonium citrate bath at a current density of 600 mAcm -2. XRD analysis shows that the deposit contains an amorphous matrix having embedded nanocrystals of the FCC phase of the solid solution of Fe and W in Ni with the average crystal grain size of 8.8 nm. The deposit has a high internal microstrain value and a high minimum density of chaotically distributed dislocations. The effect of milling and annealing of the Ni-11.3Fe-1.4W alloy on electrical and magnetic properties was studied. Structural changes in the alloy take place during both annealing and milling. Upon deposition, the alloy was heated to 420 °C. Heating resulted in structural relaxation which induced a decrease in electrical resistivity and an increase in magnetic permeability of the alloy. Further heating of the alloy at temperatures higher than 420 °C led to crystallization which caused a reduction in both electrical resistivity and magnetic permeability. The milling of the alloy for up to 12 hours caused a certain degree of structural relaxation and crystallization of the alloy. The increase in crystal grain size up to 11 nm and the partial structural relaxation induced a decrease in electrical resistivity and an increase in magnetic permeability of the alloy. Heating the powders obtained by milling at 420 °C led to complete structural relaxation, reduced electrical resistivity, and increased magnetic permeability. During heating of the powders obtained by milling at temperatures above 420 °C, crystallization and a significant increase in crystal grain size occurred, leading to a reduction in both electrical resistivity and magnetic permeability. The best magnetic properties were exhibited by the alloys milled for 12 hours and annealed thereafter at 420 °C. In these alloys, crystal grains were found to have an optimum size, and complete relaxation took place, resulting in a maximum increase in magnetic permeability

Kvalitet vode za piće grada Užica

In 2014, the Serbian public was informed on several occasions about water supply problems in the City of Užice. The reason behind the problem was the presence of potentially toxic species Planktothrix rubescens (Cyanobacteria) in the waters of the Vrutci Reservoir (the water supply intake for the City of Užice), the alternative water supply intake Sušičko Vrelo and in the city distribution network. Although the measured concentration of hepatotoxic microcystin-LR (< 0.01 μg/L) was considerably below World Health Organisation guidelines for drinking water (1 μg/ L), the water was declared unsafe. The study presents and comments on the results of physicochemical, microbiological and biological analyses of both raw water samples collected from the water supply intakes and treated chlorinated drinking water samples from the distribution network of the City of Užice water supply system.Tokom 2014. godine javnost Srbije je nekoliko puta obaveštavana o problemima vodosnabdevanja grada Užica. Razlog je bilo prisustvo potencijalno toksične vrste Planktothrix rubescens (Cyanobacteria) u vodi akumulacije Vrutci (vodozahvata grada Užica), alternativnog vodozahvata Sušičkog vrela i u gradskoj distributivnoj mreži. Iako je izmerena koncentracija hepatotokisčnog mikrocistina-LR (< 0,01 μg/L) bila znatno niža од dozvoljene vrednosti propisane od strane Svetska zdravstveno organizacije (1 μg/L), voda je proglašavana zdravstveno neispravnom. U radu su prikazani i komentarisani rezultati fizičko-hemijskih, mikrobioloških i bioloških analiza sirove vode vodozahvata kao i prečišćene i hlorisane vode za piće iz distributivne mreže gradskog vodovoda Užice