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The gas flow distribution inside a blast furnace affects its smelting. Laser surface detection technology can control the gas flow distribution and promote the stable and smooth running of blast furnace by observing and adjusting the surface condition in the blast furnace in real-time. The laser surface inspection technology in blast furnace gas flow control and optimization was introduced, with Masteel 4,000 m3 blast furnace as an example. The results showed that the 30 W high-power laser had good penetration performance and could obtain clear scanning images of the material surface. In the process of strengthening smelting, the laser detection system determined that the central airflow of blast furnace was insufficient, resulting in a decrease in furnace condition stability, and promptly took measures to adjust the angle of the mineral coke fabric equipment and lifting line. After adjusting the material line, the central airflow was properly suppressed and stabilized, the angle of edge platform increased, the airflow developed properly, and two suitable gas flows were formed, which finally stabilized the furnace condition. Meanwhile, the small duct airflow other than the central airflow was found in time through the laser detection system, which provided conditions for operators to take measures to effectively eliminate the duct airflow, thereby avoiding big impacts on the blast furnace operation and technical and economic indexes. Therefore, the laser surface detection technology could effectively judge the gas flow distribution in the furnace, which contributed to timely adjustment of process parameters and optimization of blast furnace operation.

Grease is extensively used in rolling bearings due to its inherent sealing properties. However, mechanical degradation typically occurs, resulting in a significantly shorter lifespan for the grease compared to the bearing. Investigating aging mechanisms is essential. This study utilized rolling bearings to obtain mechanically aged greases. The aged samples were then subjected to do rheological test, FTIR test and friction test to examine the effects of aging time, radial load, and rotational speed. An innovative disk-ball-disk device was developed to study the friction characteristics of aged grease in rolling bearings. Additionally, a grease lubrication and friction model were proposed to further evaluate the lubrication performance of aged grease, using measured rheological parameters and the kinematic velocities of the disk-ball-disk device as inputs. The calculated friction coefficients matched well with disk-ball-disk experimental results. FTIR analysis revealed that the non-soap thickener's structure remained stable, but additives depleted at high speeds. The structure of lithium soap thickener decomposed severely, leading to oil bleeding and a shortened replenishment duration. Over aging time, both greases had lower friction and viscosity due to gradual thickener breakdown, releasing bled oil and extending replenishment. Radial load minimally affected the properties of aged grease. This study may provide valuable insights into the aging mechanisms of grease and the enhancement of rolling bearing lubrication. [ABSTRACT FROM AUTHOR]

The reduction of hematite with ammonia is a potentially environmentally friendly method of ironmaking. Previous studies on ammonia reduction of pellets typically involved samples weighing only 2.8 g and lacked detailed activation energy analysis for the ammonia-hydrogen co-reduction of pellets. Therefore, to further investigate the reduction thermodynamics and kinetics of NH3–H2 reduction of pellets, this study uses 50 g pellets for reduction experiments. By increasing the pellet mass, the study expands the scope of kinetic research on ammonia reduction of pellets. The results indicate that nitrogen gas produced from ammonia decomposition reduces the equilibrium components of the reducing gas. In the temperature range of 700–850 °C, the formation of iron nitride exhibits a narrow range during ammonia reduction of hematite. In the reduction of 50 g of pellets, the reduction rate using 100% NH3 is lower than that using a 50% NH3 and 50% H2 mixed gas, which is, in turn, slower than using 100% H2. As temperature increases, the reduction effect of 50% NH3 and 50% H2 approaches that of 100% H2. Among common gas-solid reaction mathematical models, the Phase-boundary-controlled model with the Contracting Cylinder Model is selected as the most plausible mechanistic function. For the reduction of 50 g of pellets, the activation energies for reactions using 100% NH3, 50% NH3 and 50% H2, and 100% H2 are 65.42, 54.37, and 29.17 kJ/mol, respectively. The decomposition of NH3 has a negative effect on the reduction of Fe2O3. XRD analysis and electron microscopy element line scanning show that Fe4N is formed during the reduction of Fe2O3 with 100% NH3. The use of a 50% NH3 and 50% H2 mixture significantly reduces the formation of Fe4N during the reduction of the pellets. [ABSTRACT FROM AUTHOR]

Background and Purpose: Skin flaps are among the most important means of wound repair in clinical settings. However, partial or even total distal necrosis may occur after a flap operation, with severe consequences for both patients and doctors. This study investigated whether tert‐butylhydroquinone (TBHQ), a known agonist of the transcription factor nuclear factor erythroid 2‐related factor 2 (Nrf2), and an antioxidant, could promote skin flap survival. Experimental Approach: McFarlane skin flap models were established in male Sprague–Dawley rats and then randomly divided into control, low‐dose TBHQ, and high‐dose TBHQ treatment groups. On postoperative day 7, the survival and blood flow of the skin flaps were assessed. Using flap tissue samples, angiogenesis, inflammation, apoptosis, autophagy, and Nrf2/haem oxygenase 1 (HO‐1) signalling pathway activity were measured with immunohistochemical techniques and western blotting. Key Results: TBHQ dose‐dependently stimulated the Nrf2/HO‐1 signalling pathway, inducing autophagy through the up‐regulation of LC3B and beclin 1 and concurrently suppressing p62 expression. Additionally, TBHQ hindered apoptosis by enhancing Bcl‐2 expression while inhibiting the expression of Bax. It suppressed inflammation by inhibiting the expression of interleukin 1β, interleukin 6, and tumour necrosis factor‐α and enhanced angiogenesis by promoting the expression of vascular endothelial growth factor. Conclusion and Implications: In summary, TBHQ promoted flap survival in rats by up‐regulating the Nrf2/HO‐1 signalling pathway. As TBHQ is already widely used as a food additive, it could offer an acceptable means of improving clinical outcomes following skin flap surgery in patients. [ABSTRACT FROM AUTHOR]