Steelmaking industries have been facing strict decarbonization guidelines. With a net zero carbon emissions target, European policies are expected to be accomplished before 2050. Traditional steelmaking industry still operates by the carbothermic reduction of iron ores for steel production. Consequently, the steel sector is responsible for a large amount of CO2 emissions, accounting for up to 9% of the CO2 worldwide emissions. In this scope, the electrochemical reduction or electrolysis of iron oxides into metallic iron in alkaline media arises as a promising alternative technology for ironmaking. Significant advantages of this technology include the absence of CO2 emissions, non-polluting by-products such as hydrogen and oxygen gases, lower temperature against the conventional approach (∼100°C versus 2000°C) and lower electric energy consumption, where around 6 GJ per ton of iron manufactured can be spared. The present minireview discusses the progress on the electrochemical reduction of iron oxides in alkaline media as a green steelmaking route. A historical overview of the global steelmaking against recent developments and challenges of the novel technology is presented, and the fundamental mechanisms of iron oxide reduction to iron and alternative iron feedstocks are discussed. Factors affecting the Faradaic efficiencies of the alkaline electroreduction of iron oxide suspensions or iron oxide bulk ceramics are also explored, focusing on the concurrent hydrogen evolution reaction. Overall, if scrutinized, this technology may become a breaking point for the steel industry sector.
Defect Formation and Transport in La0.95Ni0.5Ti0.5O3-δ. -The ceramic title material is characterized by SEM/EDS, XRD, XPS, dilatometry, conductivity, Seebeck coefficient measurements, and atomistic simulations. At room temperature the title compound crystallizes in the orthorhombic space group Pbnm. The total conductivity of the compound is predominantly p-type electronic. The ionic conductivity is low and has an extremely high activation energy. Defect association, particularly the formation of ternary clusters involving Ni 3+ and La and O vacancies, and strong distortions in the oxygen sublattice around defect clusters appear to be responsible for the low ionic and electronic conductivities. -(YAKOVLEV, S. O.; KHARTON*, V. V.; NAUMOVICH, E. N.; ZEKONYTE, J.; ZAPOROJTCHENKO, V.; KOVALEVSKY, A. V.; YAREMCHENKO, A. A.; FRADE, J. R.; Solid State Sci. 8 (2006) 11, 1302-1311; Dep. Ceram. Glass Eng., Univ. Aveiro, P-3810 Aveiro, Port.; Eng.) -W. Pewestorf 07-014
We studied the dynamics of mouse-like rodent communities in the area of self-growing vegetation, which had undergone deforestation. The research is based on the results of continuous monitoring conducted from 1978 to 2019. Pitfall traps was the method of catching small mammals during the monitoring period. We used Simpson’s Diversity Index to quantify species diversity. The community similarity was evaluated by the percentage of species through Czekanowski-Sørensen Index. The studies were carried out near the “Azhendarovo” Biological Station (54°45ʹ N, 87°01ʹ E). The results of the studies showed that natural primeval communities of the taiga zone before deforestation were characterized by a multidominant structure. The dominant group included the Alexandromys oeconomus Pallas, 1776, and codominant species are represented by the genus Clethrionomys. A characteristic feature of the small mammals’ population of taiga forests is the preponderance of the Apodemus peninsulae (Thomas, 1907) over the Apodemus agrarius Pallas, 1771. On meadowlands, the genus Microtus voles prevailed. These were largely the Al. oeconomus, which accounted for 43% of all mouse-like rodents. After the deforestation, the structure changed. In the early stage of deforestation, the dominant species among rodents was the Al. oeconomus. The composition of dominant species in the recovering areas of cut-down taiga began to approach to the original state 40 years after the deforestation. Meadow communities followed the path of transformation, having no analogs in the initial period and were characterized by a significant amount of ruderal vegetation.
Thermoelectric conversion may take a significant share in future energy technologies. Oxide‐based thermoelectric composite ceramics attract attention for promising routes for control of electrical and thermal conductivity for enhanced thermoelectric performance. However, the variability of the composite properties responsible for the thermoelectric performance, despite nominally identical preparation routes, is significant, and this cannot be explained without detailed studies of thermal transport at the local scale. Scanning thermal microscopy (SThM) is a scanning probe microscopy method providing access to local thermal properties of materials down to length scales below 100 nm. To date, realistic quantitative SThM is shown mostly for topographically very smooth materials. Here, methods for SThM imaging of bulk ceramic samples with relatively rough surfaces are demonstrated. “Jumping mode” SThM (JM‐SThM), which serves to preserve the probe integrity while imaging rough surfaces, is developed and applied. Experiments with real thermoelectric ceramics show that the JM‐SThM can be used for meaningful quantitative imaging. Quantitative imaging is performed with the help of calibrated finite‐elements model of the SThM probe. The modeling reveals non‐negligible effects associated with the distributed nature of the resistive SThM probes used; corrections need to be made depending on probe‐sample contact thermal resistance and probe current frequency.
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