Cyber-based design for additive manufacturing using artificial neural networks for Industry 4.0

Additive Manufacturing (AM) requires integrated networking, embedded controls and cloud computing technologies to increase their efficiency and resource utilisation. However, currently there is no readily applicable system that can be used for cloud-based AM. The objective of this research is to develop a framework for designing a cyber additive manufacturing system that integrates an expert system with Internet of Things (IoT). An Artificial Neural Network (ANN) based expert system was implemented to classify input part designs based on CAD data and user inputs. Three ANN algorithms were trained on a knowledge base to identify optimal AM processes for different part designs. A two-stage model was used to enhance the prediction accuracy above 90% by increasing the number of input factors and datasets. A cyber interface was developed to query AM machine availability and resource capability using a Node-RED IoT device simulator. The dynamic AM machine identification system developed using an application programme interface (API) that integrates inputs from the smart algorithm and IoT interface for real-time predictions. This research establishes a foundation for the development of a cyber additive design for manufacturing system which can dynamically allocate digital designs to different AM techniques over the cyber network.     

Zn2+ complexes of di- and tri-nucleating azacrown ligands as base-moiety-selective cleaving agents of RNA 3',5'-phosphodiester bonds: binding to guanine base

The ability of the dinuclear Zn2+ complex of 1,4-bis[(1,5,9-triazacyclododecan-3-yloxy)methyl]benzene (L(1)) to promote the cleavage of the phosphodiester bond of dinucleoside-3',5'-monophosphates that contain a guanine base has been studied over a narrow pH range from pH 5.8 to 7.2 at 90 degrees C. Comparative measurements have been carried out by using the trinuclear Zn2+ complex of 1,3,5-tris[(1,5,9-triazacyclododecan-3-yloxy)methyl]benzene (L(2)) as a cleaving agent and guanylyl-3',5'-guanosine (5'-GpG-3') as a substrate. The strength of the interaction between the cleaving agent and the starting material has been elucidated by UV spectrophotometric titrations. The speciation and binding mode have been clarified by potentiometric titrations with hydrolytically stable 2'-O-methylguanylyl-3',5'-guanosine and 1H NMR spectroscopic measurements with guanylyl-3',5'-guanosine. The results show that the guanine base is able to serve as a site for anchoring for the Zn2+-azacrown moieties of the cleaving agents L(1) and L(2), analogously to uracil base. The interaction is, however, weaker than with the uracil base and, hence, only the 5'-GpG-3' site (in addition to 5'-GpU-3' and 5'-UpG-3' sites) is able to markedly modulate the phosphodiester cleavage by the Zn2+ complexes of di- and trinucleating azacrown ligands containing an ether oxygen as a potential H-bond-acceptor site.