In this study, calcium-phosphate (Ca-P) and graphene oxide (GO)/ calcium-phosphate (Ca-P) coatings were electrodeposited with different pulsed current densities on TiO2 nanotubes. Results showed that the co-electrodeposition rate in the presence of GO, especially at low current densities of 2 and 5 mA/cm2, significantly decreased. This might be due to the large size of GO sheets as compared to ...

Pulsed electrolysis of copper has been systematically investigated by electrodepositing copper from a copper sulfate bath. Pulse duty cycles of 5 to 80 percent, at frequencies from 10 to 100 Hz with current densities ranging from 2.5 to 7.5 A/dm2 were employed. The appearance of Hull Cell panels with both direct current and pulsed current was recorded. The influence of pulsed current on current...

oil and gas transmission pipelines are critical items of infrastructure in providing energy sources to regions and countries. steel pipes are commonly used which can be subject to both internal and external corrosion. this paper presents an advanced nondestructive inspection technique for detection of oil-gas pipeline corrosion defect. the pulsed eddy current (pec) method has been successfully ...

austenitic stainless steel sheets have gained wide acceptance in the fabrication of components, which require high temperature resistance and corrosion resistance such as metal bellows used in expansion joints in aircraft, aerospace and petroleum industries. in the case of single pass welding of thinner sections of this alloy, pulsed current micro plasma arc welding (pcmpaw) has been found bene...

Room-temperature continuous-wave ~cw! operation is demonstrated with InGaN multiple-quantum-well laser diodes containing an asymmetric waveguide structure. Pulsed threshold current densities as low as 5.2 kA/cm have been obtained for ridge-waveguide laser diodes grown on sapphire substrates by metal-organic chemical vapor deposition. For improved thermal management, the sapphire substrate was t...

Room-temperature (RT) pulsed operation of blue (420 nm) nitride-based multiquantum-well laser diodes grown on a-plane and c-plane sapphire substrates has been demonstrated. Structures investigated include etched and cleaved facets as well as doped and undoped quantum wells. A combination of atmospheric and low-pressure metal organic chemical vapor deposition using a modified two-flow horizontal...

Room-temperature continuous-wave operation of large-area (120 microm x 980 microm) GaAs/AlGaAs graded-refractive-index separate-confinement heterostructure lasers on (100) Si substrates has been obtained. Minimum threshold-current densities of 214 A/cm(2) (1900-microm cavity length), maximum slope efficiencies of about 0.8 W/A (600-microm cavity length), and optical power in excess of 270 mW/fa...