Influence of external magnetic field on the electrolytic hydrogen evolution on different cathode materials

The correlation between magnetic properties of cathodic materials on the evolution of hydrogen and the separation factor was found. The cathodes were pure Ni and cathodes with the electrocatalytic coatings of following compositions: Ni-Mo (70- 30%), Ni-V (70-30%), Co-Mo (70-30%) and Fe-Mo (60-40%), on Ni substrate. The electrolyte is standard electrolyte (30% KOH) and electrolyte activated with Co-complex [1].Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Microwave assisted electrolysis of alkaline water solution

The effect of microwaves (MW) on the electrolytic process of 6M KOH water solution is investigated in the temperature range from 291 K to 337 K. At lower temperatures, microwaves facilitate electrolytic process, whereas the effect is reversed at higher temperatures.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Electrocatalytic effects of Mo-Pt intermetallics singly and with ionic activators. Hydrogen production via electrolysis

The intermetallic phases along the Pt-Mo phase diagram, singly or in combination with specific ionic activators, have been investigated as cathode materials for the production of hydrogen by electrolysis from water KOH solutions in an attempt to decrease energy consumption. The influence of ionic activators (activating compounds) on energy consumption was significant. The intermetallic phases, as cathode materials, were activated by the surface deposition of activating compounds from electrolyte. The influence of these cathode materials on the electrolytic evolution of hydrogen was discussed in the context of transition metals features and their electronic configuration. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved

Analiza dimenzija mikroelemenata otiska u postupku provere originalnosti dokumenata

The paper discusses methods for determining the specificity of reproductions (forgeries) of protected documents obtained through various printing techniques. The methods are based on the analysis of printed proofs and measuring of dimensions of characteristic, enlarged details, obtained with a microscope and a digital camera. The software for the analysis is Image Pro Plus. The paper defines methods for measuring the two dimensional parameters: line width and screen dot’s radius. Proofs of reproductions were examined of the vehicle registration card and the FRY passport, obtained with digital printers and offset printing machines, and it was proved that the discussed geometric characteristics may be used as the criteria for detection of forgeries.U radu su navedene metode za određivanje specifičnosti reprodukcija (falsifikata) zaštićenih dokumenata dobijenih različitim tehnikama štampanja. Metode se baziraju na analizi štampanih otisaka i merenju dimenzija karakterističnih, uvećanih detalja, dobijenih pomoću mikroskopa i digitalne kamere. Kao softver za analizu koristi se program Image Pro Plus. Definisane su metode za merenje dva dimenziona parametra: širine linije i poluprečnika rasterske tačke. Ispitani su otisci reprodukcija saobraćajne dozvole i pasoša SRJ, dobijeni pomoću digitalnih štampača i ofset štamparskih mašina. Pokazano je da se razmatrane geometrijske karakteristike mogu koristiti kao kriterijum za utvrđivanje falsifikata

Doprinos razvoju nove mikrozapreminske/mikro-koncentracione kvantitativne analize - određivanje morfina

The results of investigation of a new kinetic analytical method for microquantitative (microconcentration/microvolume) determination of morphine is given. This method is based on potentiometric monitoring of the concentration perturbations of the Bray-Liebhafsky reaction as the oscillatory reaction system being in a stable non-equilibrium stationary state close to a bifurcation point. The experiments are carried out in an open reactor at T=310 K. The response of the matrix system to perturbations by different concentrations of morphine ethanolic solutions is followed by a Pt-electrode. In the concentration range from 0.11 to 2.90 μg mL-1 (3.14´10-7 - 7.65´10-6 mol dm-3) of morphine, a linear response of the maximal potential shift versus the logarithm concentrations of morphine is found. The average relative standard deviation of morphine determination in 5% ethanol solution is 5,4%. The detection limit of the morphine concentration is 41 ng mL-1. The accuracy of the method is 98.5%. The method is simple, reliable and cheap.Daju se rezultati istraživanja nove kinetičke metode mikrozapreminskog/mikrokoncentracionog određivanja morfina. Ona se zasniva na potenciometrijskom praćenju odgovora analitičke matrice - nelinearnog reakcionog sistema Bray-Liebhafsky u neravnotežnom stacionarnom stanju u blizini bifurkacione tačke na impulsne perturbacije različitim količinama alkoholnog rastvora alkaloida morfina. U uslovima korišćene izotermalne (T=310 K) analitičke matrice, koja je realizovana u protočnom dobromešajućem reaktoru, promena potencijala Pt-oksidoredukcione elektrode izazvana perturbacijom sa morfinom u odnosu na potencijal koji karakteriše neravnotežno stacionarno stanje neperturbovane analitičke matrice, pokazuje linearnu zavisnost od logaritma količine morfina u području od 0,11-2,90 μg mL-1 (3,14x10-7 do 7,65x10-6 mol dm-3) morfina. Pri tome je srednja relativna standardna devijacija određivanja morfina u 5% alkoholnom rastvoru 5,4%, detekcioni limit 41 ng mL-1, a tačnost 98,5%. Metoda je jednostavna pouzdana i jeftina

Electrochemical H/D isotope separation efficiencies on Ti-Ni intermetallic phases and alloys in relation to their hydridic and catalytic properties

Single Ti and Ni metals, their intermetallic phases (stable and unstable) and alloys along the Ti-Ni phase diagram, have been investigated as cathode materials for separation of hydrogen isotopes (protium and deuterium, H/D) by water electrolysis from alkaline solutions. The HID separation factors obtained were compared with the hydridic features and electrocatalytic properties for the hydrogen evolution (HER), enthalpies of intermetallic formation, and in common with similar behavior of transition elements along the Periodic Table, therefrom a close correlation amongst them resulted. The Ti-Ni intermetallic phases, as hypo-hyper-d-electronic combination of transition metals, obey typical volcano plots for all the mutually compared properties along their phase diagram. The TiNi3 alloy with an average d(8)-electronic configuration creates maximal electrocatalytic activity for both hydrogen evolution and HID electrochemical separation processes, as well as maximal enthalpy of formation. At the same time the best hydridic intermetallic phases (Ti2Ni and TiNi) and alloys (between d(4) and d(5)) exhibit lower values upon each specific curve. The similarity between those properties suggests that, alike along individual transition series, there exist the same electronic configuration causes which correlate them and determine the whole electrode kinetics. (C) 2000 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved