Evolution Of Geometrical Parameters Research Articles

Experimental hot-wire characterisation of the turbulent jet produced by a sweeping jet actuator in a quiescent environment

The present work presents the design and the characterisation of a sweeping jet, a fluidic actuator that has been shown to be able to enhance the aerodynamic performance of flow applications as transportation vehicles. The principles and operation of this type of actuator are detailed here. An experimental apparatus with hot-wire anemometry was installed to describe the flow topology produced by the sweeping jet. Basic analysis shows that the jet generates a flow with an average velocity of 60<Umean<100ms−1, a flow rate between 1.3 and 3 gs−1, and an oscillating frequency up to 2200Hz. The produced jet geometry is also analysed and shows interesting behaviour. The evolution of geometrical parameters is influenced by a transonic transition inside the actuator. To analyse the turbulent properties of the external flow, spectral triple decomposition is developed and used on the experimental data. A strong impact of the transition from a subsonic to a transonic regime on the produced flow is highlighted. The analysis of the turbulence produced by the sweeping jet shows a separation of the flow in three different zones detailed in the article. The study highlights promising results for future flow control implementations.

Computational Framework for Modeling In-Stent Restenosis1

Computational Framework for Modeling In-Stent Restenosis1

Induction of a hexagonal phase in phospholipid-surfactant bilayers

The possibility of modifying the curvature of lipid bilayers by mixing them with additives is demonstrated and the evolution of geometrical parameters with composition is discussed. X-ray diffraction patterns of the POPC/C12EO2/2H2O system were observed as a function of the relative humidity. The formation of an unexpected hexagonal phase indicates peculiar behaviour in these mixtures. The cylinder radius of this phase is considerably smaller than previously observed in cubic phases. A discussion of the head group interactions is presented. We have also been able to show that the uptake of water by the Lβ gel phase is higher as a single phase than in the Lβ+HII two phase region. The water content is important for the stabilization of HII phase and determination of its characteristic dimensions. However, it is argued that the interaction between the surfactant and the lipid is the key factor for its formation and that the EO2 head groups displace water from the inner parts of the polar region of the mesogenic units.

Electronic structure of the transition-metal-carbene-like complexes (CO)5Mo-M'H2 (M' = carbon, silicon, germanium and tin). A theoretical study based on ab initio CASSCF calculations

A theoretical study of the bond between a transition metal and an element of group 14 is reported. Based on quantum-mechanical calculations carried out at Hartree-Fock SCF and CASSCF levels, the molecular structure of the series (CO) 5 Mo=M'H 2 , M'=C, Si, Ge, and Sn, has been determined. The Mo=M'double-bond structure corresponds to the well-known sp σ -donor/p π -acceptor scheme, which becomes less efficient for the heavier terms of the series. Evolution of geometrical parameters is discussed and found in excellent agreement with experimental trends