Dynamic optimization analysis of a stored energy motor with serious unbalanced mass distribution
The rotor-bearing system of a stored energy motor, which is composed of exciter, main generator and asynchronous motor, has typical characteristics of serious unbalanced mass distribution. According to the rotor and bearing system of the stored energy motor, dynamic performance optimization analyses are carried out by means of the finite element analysis method, to give the system optimization method and to establish the system optimization plan.
3 D Finite Element Modeling and Vibration Analysis of Gas Turbine Structural Elements
This paper is dedicated to the topical problem of vibration reliability of gas turbine units. One of the most urgent problems during design and manufacturing of gas turbine units is the provision of reliability and durability of unit's joints by development and application of perspective turbomachines constructions with application of up-to-date CAD/CAE/CAM-technologies. This paper is devoted to finite element analysis of rotors and casings vibration analysis for various gas turbine units. In the present paper natural frequencies of the gas turbine unit rotor with varying bearings stiffness are analyzed for axisymmetrical model. Transient process of rotor vibrations after 4-th cascade blade breakaway is also analyzed. Finite element modeling and analysis of natural frequencies of full-scale gas turbine turbocompressors models and power turbine spatial model is carried out.
Negatively charged phospholipids trigger the interaction of a bacterial Tat substrate precursor protein with lipid monolayers.
Folded proteins can be translocated across biological membranes via the Tat machinery. It has been shown in vitro that these Tat substrates can interact with membranes prior to translocation. Here we report a monolayer and infrared reflection-absorption spectroscopic (IRRAS) study of the initial states of this membrane interaction, the binding to a lipid monolayer at the air/water interface serving as a model for half of a biological membrane. Using the model Tat substrate HiPIP (high potential iron-sulfur protein) from Allochromatium vinosum, we found that the precursor preferentially interacts with monolayers of negatively charged phospholipids. The signal peptide is essential for the interaction of the precursor protein with the monolayer because the mature HiPIP protein showed no interaction with the lipid monolayer. However, the individual signal peptide interacted differently with the monolayer compared to the complete precursor protein. IRRA spectroscopy indicated that the individual signal peptide forms mainly aggregated β-sheet structures. This β-sheet formation did not occur for the signal peptide when being part of the full length precursor. In this case it adopted an α-helical structure upon membrane insertion. The importance of the signal peptide and the mature domain for the membrane interaction is discussed in terms of current ideas of Tat substrate-membrane interactions.