Concentration of basic amino acids by electrodialysis

The specific features of concentration of basic amino acids by electrodialysis with bipolar membranes have been studied. The relationships of the process efficiency, described by the concentration factor, with the current density, the concentration of the initial solution, and the nature and characteristics of cationexchange and bipolar membranes used in the system have been obtained. It has been shown that electroosmotic transport of water along with amino acid ions through cation-exchange membranes limits the concentration efficiency. The influence of the size and hydration of the side groups of amino acids on the magnitude of electroosmotic flux has been revealed.     

Influence of the surface mechanical pulsed treatment on the oxidation of Fe – 0.2C – 13Cr – 0.3Si steel in lead melts

We study the influence of mechanical pulsed treatment (MPT-1) on the corrosion resistance of Fe – 0.2C – 13Cr – 0.3Si steel in a lead melt containing 1.3 · 10^{– 3} wt.% of oxygen at a temperature of 550°C for 1000 h. It is shown that the MPT promotes the formation of micro- and macrodefects in the subsurface zone of the specimens, which intensifies the process of oxidation of steel. The oxidation resistance of steel after MPT-2 and MPT-3 (with adding aluminum and silicon) is attained as a result of the formation of a hardened zone with nanocrystalline structure and large lengths of grain boundaries intensifying the diffusion of chromium into the oxide films.     

Analysis of Degradation Mechanisms of Gate Dielectrics Based on SiO2 in MOS Transistors

Semiconductors - The current mathematical models of gate dielectric degradation are used to determine the value of a device’s operating time to failure depending on its internal properties...     

OLEDs based on some mixed-ligand terbium carboxylates and zinc complexes with tetradentate Schiff bases: Mechanisms of electroluminescence degradation

Mixed-ligand terbium carboxylates—Tb(Carb)₃(TPPO)₂ (HCarb = HSal (salicylic acid), Hpobz (2-phenoxybenzoic acid); TPPO = triphenylphosphine oxide) and zinc complexes with tetradentate Schiff bases—ZnSB (H₂SB = H₂SAL1, H₂SAL2 (derivatives of salicylic aldehyde); H₂MO1, H₂MO2 (derivatives of o-vanillin)) were used as electroluminescent (EL) layers in organic light emitting diodes (OLEDs). These devices have undergone reversible and irreversible mechanisms of EL degradation. The reversible one is mainly associated with charge carrier trap filling. At the same time several mechanisms of irreversible degradation were observed under UV light irradiation, heating and ageing in ambient conditions. The degradation mechanisms of OLEDs under heating from 293 K to 320 K were related to the changes in the interface regions. The initial degradation was eliminated by (1) an application of alternating bias voltage; (2) a decrease of the substrate temperature and the velocity of the thermal evaporation of materials. The degradation of OLEDs was not observed under low UV irradiation that is promising for OLEDs operation under day light.