A cellulose liquid crystal motor: a steam engine of the second kind

The salient feature of liquid crystal elastomers and networks is strong coupling between orientational order and mechanical strain. Orientational order can be changed by a wide variety of stimuli, including the presence of moisture. Changes in the orientation of constituents give rise to stresses and strains, which result in changes in sample shape. We have utilized this effect to build soft cellulose-based motor driven by humidity. The motor consists of a circular loop of cellulose film, which passes over two wheels. When humid air is present near one of the wheels on one side of the film, with drier air elsewhere, rotation of the wheels results. As the wheels rotate, the humid film dries. The motor runs so long as the difference in humidity is maintained. Our cellulose liquid crystal motor thus extracts mechanical work from a difference in humidity.

New Steel Alloys for the Design of Heat Recovery Steam Generator Components of Combined Cycle Gas Plants

Demand for power is growing every day, mainly due to emerging economies in countries such as China, Russia, India, and Brazil. During the last 50 years steam pressure and temperature in power plants have been continuously raised to improve thermal efficiency. Recent efforts to improve efficiency leads to the development of a new generation of heat recovery steam generator, where the Benson once-through technology is applied to improve the thermal efficiency. The main purpose of this paper is to analyze the mechanical behavior of a high pressure superheater manifold by applying finite element modeling and a finite element analysis with the objective of analyzing stress propagation, leading to the study of damage mechanism, e.g., uniaxial fatigue, uniaxial creep for life prediction. The objective of this paper is also to analyze the mechanical properties of the new high temperature resistant materials in the market such as 2Cr Bainitic steels (T/P23 and T/P24) and also the 9-12Cr Martensitic steels (T/P91, T/P92, E911, and P/T122). For this study the design rules for construction of power boilers to define the geometry of the HPSH manifold were applied.