Search results for "electrode"

Influence of the tip effect of a carbon nanostructure on low current electrical arc initiation

2009

During their setting off, circuit breakers and vacuum switch devices are accompanied by an electric arc whose physical and chemical properties are governed by emissive current sites at the cathode surface called cathode spots. Assuming the continuity of the current on the cathode surfaces, the cathode spots contribute to supply the electrical arc by electron emission and material ejection. Thus they cause erosion on the contact electrodes inducing a dysfunction of contactors. The apparition of these cathode spots is due essentially to dust particles and surface irregularities at different scales. This experimental work represents a contribution to the understanding of the electrical arc beh…

Extra tension at electrode-nanowire adhesive contacts in nano-electromechanical devices

2017

Abstract We report a strong tangential component of the reaction force at electrode to nanowire adhesive contact which was previously established using electrostatic attraction. The reaction force tangential component absolute value was found to be comparable to or even bigger than the corresponding normal component. This effect is important for understanding of the mechanics of nano-electromechanical devices. Both the experiment and the corresponding theory are presented. Fitting of the obtained analytical solutions to experimental data was used to measure the reaction force acting at the contact for several nanowire-electrode configurations.

Use of RGB digital video analysis to study electrochemical processes involving color changes

2017

Color changes on an electrode surface during the course of electrochemical processes were monitored by in situ digital video recording. The evolution of standard red, green and blue (sRGB) intensity channels extracted from digital images showed a close relationship with the electrochemical processes taking place. In particular, the derivative of the sRGB mean intensity with respect to time (dI−/dt) gave useful insights into the electrochemical mechanism. The standard deviation (std) of the sRGB intensity provided information about the color homogeneity of the studied region on the electrode surface. We selected poly(o-toluidine) electrochromism on a transparent electrode and anodic copper d…

Real-time Electrode Misalignment Detection Device for RSW Basing on Magnetic Fields

2020

Parametrical study of multilayer structures for CIGS solar cells

2014

In this paper, a numerical analysis of relevant electrical parameters of multilayer structures for CIGS-based solar cells was carried out, employing the simulation software wxAMPS. In particular, we have focused on thin film cells having a ZnO:Al/ZnO/CdS/CIGS structure with a Molybdenum back contact. The aim of this work is to establish good theoretical reference values for an ongoing experimental activity, where our technology of choice is the single-step electrodeposition. In detail, we have analyzed how the main electrical properties change with the bang gap and the thickness of the absorber layer, for such a type of solar cell structure. Our results show that both efficiency and fill fa…

Effects of electrolyte doping on electrodeposited nanostructured manganese oxide and chromium oxide

2020

Abstract Electrolyte additions are used to control the functionality of a nanostructured oxide. Dopant ions affect the size and shape of deposit crystallites and modify the host structure. Such ions can be incorporated into the deposit or form a separate oxide phase. The manganese dioxide family of polymorphs with ion-molecular sieve properties represents the additional possibilities of “template” effects of dopant ions on the phase composition, heterovalent substitution in the cationic sublattice, changes in morphology and alteration of nanocrystallite size during electrocrystallisation. The effects of electrolyte doping in electrodeposited, non-stoichiometric manganese dioxide (NH4+, Li+ …

Influence of sulphite on the passivation of iron

1991

Abstract Mossbauer spectroscopy and electrochemical measurements were used to study the passivation of iron and steels in a sulphite containing solution. The potentiodynamic curves show that passivation occurs at −140 mV potential vs saturated calomel electrode ( sce ). The main phase of the passive layer was found to be γ-FeOOH, while FeSO 4 ·H 2 O on the surface and FeSO 3 ·3H 2 O inside the layer were identified as minor phases in the case of polarization in a solution of pH 3.37. Only γ-FeOOH was observed on the surface of samples polarized at pH 6.6.

Mass‐Spectrometric Imaging of Electrode Surfaces—a View on Electrochemical Side Reactions

2020

Abstract Electrochemical side reactions, often referred to as “electrode fouling”, are known to be a major challenge in electro‐organic synthesis and the functionality of modern batteries. Often, polymerization of one or more components is observed. When reaching their limit of solubility, those polymers tend to adsorb on the surface of the electrode, resulting in a passivation of the respective electrode area, which may impact electrochemical performance. Here, matrix‐assisted laser‐desorption/ionization mass spectrometry (MALDI‐MS) is presented as valuable imaging technique to visualize polymer deposition on electrode surfaces. Oligomer size distribution and its dependency on the contact …

Investigation on passivity of titanium under steady-state conditions in acidic solutions

2011

Abstract The passivity of titanium was studied using potentiostatic polarization combined with Mott–Schottky analysis in acidic solutions. The oxide layer was characterized as an n-type semiconducting, oxygen deficient oxide (TiO1.993–1.996) with a donor density in the range of 1019–1020 cm−3 depending on electrode potential and electrolyte pH. The calculated thickness for the inner oxide layer was in the range of 1–4 nm, increasing linearly with applied potential and exponentially with electrolyte pH. The potential- and pH-dependence of the inner oxide thickness was interpreted by a modified point defect model for the migration-controlled oxide growth, in which the rate-determining step in…

Temperature Effect of Ionic Transition Metal Complex Light-Emitting Electrochemical Cells

2013

ABSTRACTLight-Emitting Electrochemical Cells (LECs) consist of solution processable ionic light-emitting materials and use air stable electrodes. Their operational mechanism relies on both ionic and electronic conduction. The dynamic behavior is primarily determined by the ionic conductivity. Here, we demonstrate that with increasing temperature the LECs turn-on faster yet without decreasing the efficiency. This is due to the activation energy of ionic transport and the temperature independent photoluminescence quantum yields.