Corrosion of boiler tubes remains an operational and economic limitation in municipal waste power plants. The understanding of the nature, mechanism, and related factors can help reduce the degradation process caused by corrosion. The chlorine content in the fuel has a significant effect on the production of gaseous components (e.g., HCl) and condensed phases on the chloride base. This study aimed to analyze the effects of flue gases on the outer surface and saturated steam on the inner surface of the evaporator tube. The influence of gaseous chlorides and sulfates or their deposits on the course and intensity of corrosion was observed. The salt melts reacted with the steel surface facing the flue gas flow and increased the thickness of the oxide layer up to a maximum of 30 mm. On the surface not facing the flue gas flow, they disrupted the corrosive layer, reduced its adhesion, and exposed the metal surface. Beneath the massive deposits, a local overheating of the inner surface of the evaporator tubes occurred, which resulted in the release of the protective magnetite layer from the surface. Ash deposits reduce the boiler's thermal efficiency because they act as a thermal resistor for heat transfer between the flue gases and the working medium in the pipes. The effect of insufficient feedwater treatment was evinced in the presence of mineral salts in the corrosion layer on the inner surface of the tube.
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http://dx.doi.org/10.3390/ma14143860 | DOI Listing |
PeerJ
January 2025
Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot, Inner Mongolia, China.
Grazing can alter the physicochemical properties of soil and quickly influence the composition of microbial communities. However, the effects of grazing intensity on fungal community composition in different soil depth remain unclear. On the Inner Mongolia Plateau, we studied the effects of grazing intensity treatments including no grazing (NG), light grazing (LG), moderate grazing (MG), heavy grazing (HG), and over grazing (OG) on the physicochemical properties and fungal community composition of surface (0-20 cm) and subsurface (20-40 cm) soil layers.
View Article and Find Full Text PDFAnn Thorac Surg Short Rep
June 2024
Department of Pediatric Cardiovascular Surgery, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
The endocardial anchoring technique is a novel modification of total anomalous pulmonary venous return repair that involves creation of an L-shaped flap of the pulmonary venous confluence, subsequently anchoring it to the endocardium. A wide and smooth pathway can be expected from the theoretical advantages of this technique, namely, a smooth inner surface of the anchored flap and traction force to extend the orifice of the connection. An application of this technique for a rare variant of supracardiac total anomalous pulmonary venous return suggests its potential to be an alternative to the conventional repair, especially in patients with a curved pulmonary venous confluence.
View Article and Find Full Text PDFJ Biomech Eng
January 2025
Department of Mechanical Engineering Marshall University, Huntington, WV 25755, USA; Department of Biomedical Engineering Marshall University, Huntington, WV 25755, USA.
Cell-laden, scaffold-based tissue engineering methods have been successfully utilized for the treatment of bone fractures. In such methods, the rate of scaffold biodegradation, transport of nutrients, and removal of cell metabolic wastes are critical fluid-dynamics factors, affecting tissue regeneration. Therefore, there is a critical need to identify the underlying material transport mechanisms associated with stem cell-driven, scaffold-based bone tissue regeneration.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
Department of Chemistry, State University of New York at Binghamton, Binghamton, NY, 13902, USA; Materials Engineering and Science Program, State University of New York at Binghamton, Binghamton, NY, 13902, USA. Electronic address:
Background: Pesticides are widely used in agriculture to control pests and enhance crop yields. However, post-harvest, there are growing concerns about the potential health risks posed by pesticide residues on produce surfaces. Analyzing these residues is challenging due to their typically low concentrations and the potential interference from the complex matrix of the produce's surface.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
University of Alabama at Birmingham, Birmingham, AL, USA.
Background: The potential of plasma Aβ42/Aβ40 ratio, NfL, p-tau 181, and p-tau 217 has been extensively discussed in the literature. Our previous study explored the association between retinal biomarkers and preclinical AD. The goal of this study was to evaluate the association and a multimodal model of retinal and plasma biomarkers for detection of preclinical AD.
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