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This article analyses the effects of deformation on the structure of CMnSi steel at various deformation levels. After hot forging, the structure of CMnSi steel comprises coarse-sized alpha and pearlite particles. The average grain size of steel after forging was 100 μm. After hot rolling, the grain size gradually decreases, with the average size of the ferrite and pearlite grains measured as 60 μm. After that, CMnSi steel was subjected to cold deformation at levels of 40%, 60%, and 80%. The grain size of the CMnSi steel sample after 80% cold deformation reached level 7, corresponding to about 25 μm. For a deformation level of 40%, the grain size was level 5, corresponding to 40 μm, while a deformation level of 60% produced a grain size of 35 μm, corresponding to level 6. In addition, scanning electron microscopy showed that after 80% deformation, smaller particles with a size of about 5 μm appear inside the parent particles. Moreover, energy-dispersive X-ray spectroscopy analysis revealed the carbide appearance in the form M23C6, with M being a mixture of Fe and Mn. These carbides have a fine size of about 1–2 μm and contribute to the prevention of particle growth during subsequent heat treatments.

The aim of this study is to determine and compare the adsorption capacities, kinetic and thermodynamic parameters of the adsorption process of uranyl ions from aqueous solution on nanotube titania impregnated mesoporous silica SBA-15 (TNT-SBA-15) and naked SBA-15 (nSBA-15) adsorbents. The TNT-SBA-15 composite containing various molar ratio of nanotube titania to silica (TNT-SBA-15(m:n)) in the matrix was synthesized by the sol–gel/impregnation method using sodium silicate as a silica precursor, sulphuric acid and nanotube titania. Batch adsorption experiments showed that the maximum adsorption capacity (qmax) of the TNT-SBA-15(m:n = 1:1) composite under indoor light be as high as 2.65 mMoleU g−1 that was 1.4 times higher than that of nSBA-15 under the same conditions. Under UV (300 W) illumination the qmax of TNT-SBA-15(1:1) adsorbent reached 3.49 mMoleU g−1 that was 2 times higher than the qmax in the dark. The increase in qmax of the TNT-SBA-15(1:1) composite in the two experiments was attributed to the synergistic effect of coupled sorption and photocatalytic reduction of U(VI) by titania following the deposition of uranium (IV) (hydr)oxide on the surface of the adsorbent. The adsorption process followed a pseudo-second kinetic model. The activation energy was found to be 160 and 135 kJ Mole−1 for the adsorption on nSBA-15 and TNT-SBA-15(1:1), respectively. The isotherm of the adsorption process follows the Langmuir as well as Freundlich models. The adsorption is an endothermic and spontaneous process. Adsorbed TNT-SBA-15 can be easily regenerated in 0.3 M HNO3 solution, and the qmax of the adsorbent was maintained at 95% the initial qmax after three consecutive adsorption–desorption cycles. These results revealed that, though TNT-SBA-15 made from inexpensive reagents could be an effective adsorbent for uranyl removal from wastewater.

The multilevel indirect matrix converter (IMC) is a merit of power converter for feeding a three-phase load from three-phase power supply because it has several attractive features such as: Sinusoidal input/output currents, bidirectional power flow, long lifetime due to the absence of bulky electrolytic capacitors. As compared to the conventional IMC, the multilevel IMC provides high output performance by increasing the level of output voltage. In this paper, the novel approach topology of multilevel IMC by using the combination of the cascaded rectifier and the three-level T-Type inverter is introduced. Furthermore, the new space vector pulse width modulation (SVPWM) method for the presented multilevel IMC that eliminate the common-mode voltage is proposed in this paper. The simulation study is carried out in PSIM software to verify the proposed modulation method. Then, an experimental system is built using a three-phase RL load, a multilevel IMC, a DSP controller board and other elements to verify the effectiveness of the proposed modulation method. Some simulation and experimental results are illustrated to confirm the theory analysis.

Pulse width modulation strategies have been developed for indirect matrix converters (IMCs) in order to improve their performance. In indirect matrix converters, the LC input filter is used to remove input current harmonics and electromagnetic interference problems. Unfortunately, due to the existence of the input filter, the input power factor is diminished, especially during operation at low voltage outputs. In this paper, a new space vector modulation (SVM) is proposed to compensate for the input power factor of the indirect matrix converter. Both computer simulation and experimental studies through hardware implementation were performed to verify the effectiveness of the proposed modulation strategy.