For its good mechanical, thermal, and chemical property, ceramic materials are widely used in construction, chemical industry, electric power, communication and other fields. However, due to its particularity and complex production process, quality problems usually occur, of which the most common one is surface defects. For ceramic products, the defects are usually small and complicated, and manual methods are difficult to ensure the accuracy and speed of detection. Relevant researchers have proposed a variety of machine vision-based ceramic defect detection methods, but these methods still need to break through in solving the key problems of ceramic surface glaze reflection, complex detection environment, low algorithm efficiency and low real-time performance. To this end, this article reviews the application status of machine vision on ceramic surface defect detection in recent years, summarizes and analyzes the existing non-destructive testing (NDT) technology method, and points out the main factors that affect the development of ceramic surfaces defect detection technology and puts forward the corresponding solutions.
The microchannel reactor is a generally adopted laminated‐sheet structure in which several microchannel sheets with the same or different structures are laminated together and tightened by welding or other connection methods into a single reaction unit. Uniform velocity distribution among the microchannels can improve the heat and mass transfer efficiency. When one or more microchannels are blocked, the uniformity of the velocity distribution is inevitably affected. In this work, the velocity distributions among the microchannels in a single‐sheet and a double‐sheet laminated structure are investigated under different blockage conditions. It is demonstrated in detail that the different blockage conditions in the microchannels and laminated structure display different effects on the velocity value, the shape of the velocity distribution, and the evaluation parameter for uniformity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.