Comparison of online identification methods of material parameters in press straightening process
More and more automatic pressure straighteners are used on the manufacturing industry because of their high productivity and good quality. When the technologic parameters are calculated, the precision of results will be influenced by the part's material performance parameters. In this paper, three online identification methods of performance parameters were studied. They were BP neural network method, RBF neural network method and the support vector machine method. Then their identification effects were compared. It was shown that all three methods can be used to identify material performance parameters in straightening process. But later two methods have better identification precision and shorter response time than BP neural network method.
Status and Prospects of Theoretical Study on Press Straightening Technology
Because of the development of automatic straightening machines,theoretical study on press straightening technology is more and more important.In this paper,the definition of press straightening is explained.Main parameters of press straightening technology are discussed.Three calculation methods of straightening stroke are generalized and analyzed.The status of research on control methods about straightening process is illustrated.Finally,prospects of study on press straightening technology are given.
Rational Design, Synthesis and Evaluation of γ-CD-Containing Cross-Linked Polyvinyl Alcohol Hydrogel as a Prednisone Delivery Platform
This study describes the in-silico rational design, synthesis and evaluation of cross-linked polyvinyl alcohol hydrogels containing γ-cyclodextrin (γ-CDHSAs) as platforms for the sustained release of prednisone (PDN). Through in-silico studies using semi-empirical quantum mechanical calculations, the effectiveness of 20 dicarboxylic acids to generate a specific cross-linked hydrogel capable of supporting different amounts of γ-cyclodextrin (γ-CD) was evaluated. According to the interaction energies calculated with the in-silico studies, the hydrogel made from PVA cross-linked with succinic acids (SA) was shown to be the best candidate for containing γ-CD. Later, molecular dynamics simulation studies were performed in order to evaluate the intermolecular interactions between PDN and three cross-linked hydrogel formulations with different proportions of γ-CD (2.44%, 4.76% and 9.1%). These three cross-linked hydrogels were synthesized and characterized. The loading and the subsequent release of PDN from the hydrogels were investigated. The in-silico and experimental results showed that the interaction between PDN and γ-CDHSA was mainly produced with the γ-CDs linked to the hydrogels. Thus, the unique structures and properties of γ-CDHSA demonstrated an interesting multiphasic profile that could be utilized as a promising drug carrier for controlled, sustained and localized release of PDN.