Electrochemical Oxidation Assessment and Interaction of 2-aminoethanol and N, N-diethylethanamine Propagation in Acidic Medium

Electro�oxidation and inhibitor performance of copper specimens in 1 M hydrochloric acid solu� tion was investigated at room temperature by linear potentiodynamic polarization and gravimetric method in the presence of 2�aminoethanol (A) and N, N�diethylethanamine (D) as an inorganic inhibitor. The effect of the inhibitory concentration on the corrosion behavior of copper was studied over 288 hrs at 298°K. The inhibitory efficiency rise up to 96% for single induced and 98% for synergistic behavior. The adsorption mechanism characteristic was supported by SEM/EDX analysis and adsorption isotherm. From all indica� tion, the inhibitive efficiency of these compounds majorly depends on their molecular structure and concen� tration. The blocking effects of the surface interface were also explained on the basis of the inhibitor active action. 2�aminoethanol and N, N�diethylethanamine inhibits copper in 1 M HCl by strictly affecting both the anodic and cathodic sites. Portion of the surface covered calculated was also found to follow Langmuir adsorption isotherm

High-Temperature Corrosion Behavior of Different Regions of Weldment of 2.25Cr-1Mo Steel in SO2 + O2 Atmosphere

This paper investigates the corrosion behavior of different regions of weldment of 2.25Cr-1Mo steel exposed in mixed oxidation and sulfidation (SO2 + O2) environment up to 500 h at 773 K. Microstructural investigation and characterization of oxide scales are done using SEM, TEM, and XRD. The obtained results infer that heat-affected zone corrodes faster than both base and weld metal. The reaction kinetics follows a parabolic growth rate for all regions. The higher corrosion rate of heat-affected zone is attributed to the formation of Cr23C6 secondary precipitates leading to depletion of protective inner scale of the Cr-rich oxide during welding

1.55-μm range InAs/InP (100) quantum dot telecom devices

Lasing and sharp line emission in the 1.55-µm wavelength region is demonstrated from ensembles and single InAs quantum dots (QDs) embedded in InGaAsP on InP (100) by metalorganic vapor phase epitaxy (MOVPE). Wavelength tuning of the QDs is achieved through the insertion of ultra-thin (1-2 monolayers) GaAs interlayers underneath the InAs QDs. To increase the active volume widely-stacked QD layers are identically reproduced. Closely-stacked QDs reveal unpolarized emission from the cleaved side due to vertical electronic coupling which is important for polarization insensitive semiconductor optical amplifiers. Fabry-Perot narrow ridge-waveguide lasers implementing five layers of widely-stacked QDs as gain medium operate in continuous wave mode at room temperature with low threshold current, low transparency current density of 6 A/cm2 per QD layer, and low loss of 4.2 cm-1, which are accompanied by a 80 nm wide gain spectrum. Device performance does not suffer from sidewall recombination in deeply-etched QD lasers which possess similar threshold currents as shallowly-etched ones and do not deteriorate with time. This allows the fabrication of mono-mode and compact devices with small bending radii, as demonstrated by the operation of a QD ring laser with 40-GHz free spectral range. Micro-PL of single QDs exhibits sharp exciton - biexciton emission around 1.55 µm persisting to temperatures above 70 K; the prerequisite for single photon sources working at liquid nitrogen temperature for fiber-based quantum information and cryptography system