Effect of pre-deformation on the precipitation process and magnetic properties of Fe–Cu model alloys

The effect of pre-deformation on the precipitation process and magnetic properties of Fe–Cu model alloys was investigated. These specimens simulate irradiation embrittlement of nuclear reactor pressure vessel (RPV) steels. Fe–1 wt%Cu alloys with and without pre-deformation in solid-state solution were thermally aged at 773 K for various times and the evolution of hardness, conductivity, and microstructure were investigated. Pre-deformation enhanced Cu precipitation and caused precipitation at dislocations. The coercive force tended to decrease for the pre-deformed specimen and the underlying mechanism is discussed. The results obtained are related to the magnetic characteristics of irradiated RPV steels.     

Heavy metal removal from copper smelting effluent using electrochemical cylindrical flow reactor

The purpose of this study is mainly to evaluate the performance of the continuous recirculation flow cell at low current density and pH (the pH at which the effluents are available) in removing heavy metals from copper smelting effluent by cathodic reduction. During the electrolysis at different pH, % removal of heavy metals removal, energy consumption and heterogeneous reaction rate constants were investigated at given flow rate and current density on the selected industrial effluent. The overall specific energy consumption at the pH 0.64 was observed to be lowest, which is 10.99kWh/kg of heavy metal removal.     

Demodulation scheme for fiber bragg grating sensors based on active control of the spectral response of a wavelength division multiplexer

We present a closed-loop technique for measuring wavelength shifts associated with fiber Bragg gratings by using a fused biconical wavelength division multiplexer (WDM). The spectral response of the WDM is actively tuned by stretching of the coupling region to maintain a fixed coupling ratio at the reflected Bragg wavelength. The closed-loop operation allows sensitivities usually associated with a highly selective WDM to be obtained without compromising the measurement range. A simple theoretical model is presented together with experimental results for temperature and strain measurements.     

Investigation of surface properties of treated ITO substrates for organic light-emitting devices

In this work, a study of the surface properties of treated indium tin oxide (ITO) substrates is reported. We used three different cleaning treatments among others: washing in an ultrasonic bath of acetone and ethyl alcohol or isopropyl alcohol in room temperature as well as dipping into solution (prepared from NH₄OH (25 %), H₂O₂ (30 %) and distilled water) at 60 °C. The relation between ITO morphology and surface properties has been studied by contact angle, and surface energy measurements as well as the surface roughness of ITO samples evaluation by atomic force microscopy (AFM). Experimental results show that the ITO surface properties are closely related to the treatment methods. The ultrasonic degreasing in acetone and ethyl alcohol yields the highest surface energy (38.5 mJ/m²), brings about the maximum reduction in contact angles and causes the smallest increasing the surface roughness of ITO substrates.     

Theoretical investigation of electronic performance,half-metallicity,and magnetic properties of Cr-substituted BaTe

We have investigated the structural, electronic, and ferromagnetic properties of chromium (Cr)-doped rocksalt BaTe (\(\hbox {Ba}_{1-x}\hbox {Cr}_{x}\hbox {Te}\)) compounds with compositions \(x = 0.25\), 0.5, and 0.75, based on density functional theory with generalized gradient approximation of Wu–Cohen (GGA-WC) and Tran–Blaha-modified Becke–Johnson (TB-mBJ) potential using the WIEN2k package. We found that the electronic structure showed half-metallic ferromagnetic character with spin polarization of 100 % around the Fermi level. In addition, the minority-spin bands depicted a half-metallic ferromagnetic (HMF) gap and half-metallic (HM) gap. The improved HMF and HM gaps found with the TB-mBJ potential are higher than with the GGA-WC approximation. These large HM gaps make \(\hbox {Ba}_{1-x} \hbox {Cr}_{x}\hbox {Te}\) compounds promising candidates for use in spintronics applications.