Scaling Up of Non-Thermal Gliding Arc Plasma Systems for Industrial Applications

Plasma Chemistry and Plasma Processing - Scaling up of transitional “warm” plasmas to industrial level gives possibility to develop plasma systems that combine advantages of thermal and...     

Positive Lyapunov exponents for a class of ergodic Schrödinger operators

We present a simple method to estimate the Lyapunov exponent (E) for the system

Long-Lived Mesoscopic Entanglement Between Two Damped Infinite Harmonic Chains

We consider two chains, each made of N independent oscillators, immersed in a common thermal bath and study the dynamics of their mutual quantum correlations in the thermodynamic, large-N limit. We show that dissipation and noise due to the presence of the external environment are able to generate collective quantum correlations between the two chains at the mesoscopic level. The created collective quantum entanglement between the two many-body systems turns out to be rather robust, surviving for asymptotically long times even for non vanishing bath temperatures.     

Impingement cooling for modern combustors: experimental analysis of heat transfer and effectiveness

This paper presents results obtained from a wide-ranging experimental investigation into impingement cooling from multiple jet arrays which reproduced real LPP combustor liner geometries. The work was performed during the four years of the European project LOPOCOTEP. Two sparse, staggered impingement arrays were examined in detail and each case was compared with data from the literature relating to the same configuration and jet Reynolds numbers. As a result of this study, it has been possible to obtain detailed data about local distribution of the heat-transfer coefficient and spanwise row-averaged effectiveness, by using a new method which combined transient and steady-state thermochromic liquid-crystal (TLC) techniques. It was found that the data obtained in this work were in good agreement with results presented in the literature. This study shows that measured, row-by-row effectiveness values can be usefully employed in a preliminary design stage. Some data relating to hole-discharge coefficients are also presented.

---

The damage assessment of concrete structures by time-frequency distributions

This paper discusses the use of ultrasonic methodology when studying the damage caused to cubeshaped concrete specimens by uniaxial compressive loading. It uses the time-frequency distribution of the cross-ambiguity function (CAF). An algorithm capable of computing the coefficients of the Zak transform needed to discretize the crossambiguity function is also given, together with the definition of a coefficient that permits the study of different damage mechanisms and their evolution. These provide a means of effectively measuring the extent of the resulting damage. The results of the experiment show that this methology is extremely sensitive in detecting and monitoring damge processes in concrete.     

An improved nonlinear model for an automotive shock absorber

A new physical model for a shock absorber is presented which provides a more realistic representation of the stiffness characteristics than previous simple models. The new model is validated on experimental data.     

Damage localisation in plate like-structures using the two-dimensional polynomial annihilation edge detection method

The topic of non-destructively detecting localised damage in plates is addressed in this article. Since the presence of a crack or a delamination causes a discontinuity in the mode shape first derivatives, a numerical method for detecting discontinuities in smooth piecewise functions and their derivatives, based on a polynomial-annihilation technique is presented. The method, already proposed for beam-type structures, has been extended to enable the detection and localisation of damage in plate-like structures for which only post-damage mode shapes are available. Applying finite element analysis, the mode shapes of an isotropic plate with a saw-cut and a multi-layered composite plate with a delamination have been calculated and the performance of the approach evaluated for increasing amounts of noise. Encouraging results indicate that further development of the technique for non-destructive testing of plate-like structures would be highly worthwhile.