Manager & Principal Engineer for Compressors & Expanders with General Electric Oil & Gas Company, in Florence, Italy. He is responsible for all requisition, standardization, and CAD automation activities as well as detailed design of new products for centrifugal compressors, reciprocating compressors and turboexpanders both in Florence (Nuovo Pignone), Le Creusot (Thermodyn), and Oshkosh (AC). ...

Aiming at the non-stationary and stall flutter problems of wind turbine blade caused by transient load fluctuations, the dynamic properties of wind turbine were studied, the blade was simplify to a cantilever beam in case of the action of shear deformation and cross section rotating effect were considered in this analysis, equations of the blade were established based on D'Alemberts' principle ...

Flagellated bacteria, such as Escherichia coli, swim by rotating thin helical filaments, each driven at its base by a reversible rotary motor, powered by an ion flux. A motor is about 45 nm in diameter and is assembled from about 20 different kinds of parts. It develops maximum torque at stall but can spin several hundred Hz. Its direction of rotation is controlled by a sensory system that enab...

Surge is one of the two main dynamic instabilities that can occur in compressor systems (the other is the rotating stall) preventing their satisfactory operation and being potential cause of serious damages. In this paper we consider a Close Coupled Valve (CCV) as actuator, and we suggest the use of a second-order sliding-mode (2-SM) technique for the active control of the surge phenomenon. We ...

In this paper we develop globally robustly stabilizing controllers for rotating stall and surge in multimode axial flow compressor models with uncertain pressure-flow compressor performance characteristic maps. Specifically, using Lyapunov stability theory, a novel switching nonlinear globally robustly stabilizing control law based on equilibria-dependent Lyapunov functions with converging doma...

This paper studies the relationship between unsteady flow features and instantaneous torque and power performance of straight bladed vertical axis wind turbine at variable tip speed ratios. The rotor unsteady flow field simulation was carried out by using computational fluid dynamics method. The flow physics and the principle of changing flow filed acting on torque performance and power perform...

Molecular motors and cytoskeletal filaments work collectively most of the time under opposing forces. This opposing force may be due to cargo carried by motors or resistance coming from the cell membrane pressing against the cytoskeletal filaments. Some recent studies have shown that the collective maximum force (stall force) generated by multiple cytoskeletal filaments or molecular motors may ...