Search

Colon image analysis is an important step in diagnosing colon cancer, and achieving automated and accurate segmentation remains a challenging problem because of the diversity of cell shapes and boundaries in pathological sections. In this paper, we propose a U-shaped colon cancer segmentation network, which combines depth-separable convolution and morphological methods to reduce the number of model parameters and effectively improve segmentation accuracy. We improve the global and local feature capabilities by taking advantage of serial convolution and external focus as the underlying architecture for the model. We designed the skip connection to fuse the features from the encoder in a morphological way to enhance the morphological features. We introduced an edge enhancement module by extracting contour information using morphological methods to enhance edge features. We evaluated the proposed method on three colon cancer datasets, and the experimental results showed that our method with a small number of parameters has a Dice coefficient of 92.76% ± 5.86% on the Glas dataset, 86.11% ± 7.11% on the CoCaHis dataset, and 91.61% ± 11.25% on the Colon dataset. The code will be openly available at https://github.com/Yuanhaojun513/MMUNet. • We embed morphological methods into U-shaped networks for image segmentation. • We constructed the erosion-dilation and edge feature modules to enhance features. • We proposed multi-scale convolution and attention blocks to enhance features. [ABSTRACT FROM AUTHOR]

• The unexpected fracture of tube-to-tubesheet joints of a circulating oil steam generator is studied. • Caustic stress corrosion cracking is the root cause of the failure. • Proposals are given about material selection, manufacture and water quality assurance of the circulating oil steam generator. Tube-to-tubesheet joints are generally considered as one of the vulnerable part of heat exchangers, as they are sensitive to stress corrosion owing to residual stress generated during manufacture processes. As a result, it is crucial to carry out failure analysis on tube-to-tubesheet joints to ensure the safety of heat exchanger operations. The unexpected fracture of tube-to-tubesheet joints of a circulating oil steam generator in a petrochemical plant is studied. In order to find out the cause of the failure, the failed tube is investigated by visual inspection, base metal inspection and fracture morphologies observation. The results show that due to insufficient expansion of the tube, a gap is formed between the tube and tubesheet, which concentrates the alkali lye and chloride deposits, leading to the formation of caustic stress corrosion cracks in the outer wall of the failed tube before fracture, and the cracks rapidly propagate under tensile stress resulting in the failure. Finally, proposals are given about material selection, manufacture and water quality assurance of the circulating oil steam generator. [ABSTRACT FROM AUTHOR]

The effects of the formaldehyde to phenol molar ratio (F/P) on the combustion behavior of phenolic foams were discussed. Phenolic foams have been prepared with different F/P of resole resin. FTIR, TG and SEM were used for assessment of the molecular structure, thermal stability, and cell structure of phenolic foam (PF) analysis, respectively. It was found that the higher the F/P, the more inflammables content in the PF that promoted the formation of the char layer, and the higher the LOI of PF. Although the closed cell proportion of PF decreases with the increase of F/P, the effect of the open and closed cell proportion on the LOI of PF was much lower than that of the content of inflammables when there was little difference in cell size. It is worth noting that the smoldering time and smoldering velocity of PF also increased with the increase of F/P. When F/P exceeds 2.3, a large number of open-cell structures appear in the PF, resulting in a phenomenon of smoldering to burnout. The relationship between smoldering velocity and F/P can be calculated by an Arrhenius type expression. Arrhenius-type expression calculation showed that when the F/P reached 2.3, the smoldering velocity increased sharply, reaching a maximum of 0.193 mm/s. • The factors affecting the combustion behavior of phenolic foam (PF) were revealed. • The effect of closed cell proportion on LOI of PF is lower than that of the content of inflammables. • The higher the formaldehyde to phenol molar ratio (F/P), the greater the smoldering time and velocity. • The relationship between smoldering velocity and F/P can be calculated by an Arrhenius type expression. [ABSTRACT FROM AUTHOR]