Search

The applicability of superstructure optimization to process synthesis is often limited to simple models and flowsheets. The state operator network (SON) (Smith and Pantelides, 1995) overcomes some limitations via a mixer–splitter network, allowing the use of rigorous unit models. However, setting flowrates to zero for non-selected units can result in numerical issues. Here, the modified state operator network (MSON), a new exact reformulation with modified mixers and splitters, is introduced. When a unit is deselected, a fictitious, strictly positive, mixer inlet flow ensures the unit model is easily solved. A corresponding fictitious splitter outlet counteracts this inlet, resulting in correct flowsheet behaviour. When applied to a toy flowsheet, the MSON outperforms standard formulations. When applied to the synthesis of a reactor–separator network and to a challenging counter-current column synthesis problem, the MSON offers a systematic and robust approach to superstructure optimization. • A robust process synthesis framework enables use of rigorous process models. • New mixer–splitter reformulation avoids numerical singularities. • It is easily integrated with model libraries in process simulation software. • Demonstrated on several process synthesis examples, including an absorber. [ABSTRACT FROM AUTHOR]

Abstract: Wrapping with advanced composite materials improve the behaviour of concrete structural elements in terms of increase in strength, ultimate strain and corresponding stress of confined concrete. This paper deals with the performance of concrete specimens confined with fabric reinforcement in cementitious binder (FABcrete) and in organic binder consisting of resins (FABpoly). Experiments have been conducted on plain and confined concrete cylindrical specimens under compression. It has been observed from the experimental studies that the specimen confined with FABcrete enhances the load carrying capacity and ductility similar to that of FABpoly confined specimen. Further, the failure of FABcrete specimen is observed to be vertical split, which is similar to that of plain concrete specimen. In the case of FABpoly specimen, failure has been initiated in the mesh region of fabric and ultimate failure is by spalling of concrete in the same region. Also, the failure of FABcrete specimen has been less abrupt and controlled as compared to the failure behaviour of FABpoly specimen. In comparison with FABpoly, FABcrete approximately has the same effectiveness in increasing strength and a slightly inferior ultimate strain. It can be concluded that FABcrete can also be used as a confining system for retrofitting applications. [Copyright &y& Elsevier]

• Flexural impact response of glass and basalt textile reinforced mortar investigated. • Positioning of textile layers affects the impact resistance and energy absorption. • Maximum impact resistance of optimal glass and basalt textile layers are same. • Significant reduction of energy absorption under repeated impact for glass TRM. • Crack and failure pattern is influenced by number of textile layers used. The present paper investigates the characteristics of textile reinforced mortar (TRM) beams under flexural impact. The key test parameters focuses on determining the effect of the two types of textile material namely glass and basalt, number of textile layers and positioning of textile layers. TRM beams were experimentally evaluated under different energy levels with respect to the load specification. Effect of single and repeated impact was examined on standard TRM specimens. The results showed that in the case of glass and basalt textile, the optimum number of textile layers is different in order to achieve maximum impact resistance. The peak energy level for TRM with glass textiles is found to be higher than that of TRM with basalt textiles for optimal reinforcement. The energy absorption for glass TRM for single impact is higher than basalt TRM and the same is substantially reduced when subjected to repeated impact compared to basalt TRM. The crack pattern and failure mode are found to be more dependent on the number of textile layers. [ABSTRACT FROM AUTHOR]