Wind tunnel studies of circulation control elliptical airfoils

Effects of blown jets on the lift and drag of cambered elliptical airfoils are described. Performance changes due to a splitter plate attached to the lower surface of an elliptical airfoil near the trailing edge with and without blowing are indicated. Lift and drag characteristics of airfoils with two blown jets are compared with airfoils with single blowing jets. Airfoil designs that vary the location of a second jet relative to a fixed jet are described

Long-range repulsive interaction between TTF molecules on a metal surface induced by charge transfer

The low-coverage adsorption of a molecular electron donor, tetrathiafulvalene, on Au(111) is characterized by the spontaneous formation of superlattice of monomers, whose spacing exceeds the equilibrium distance of non-covalent interactions and depends on coverage. The origin of this peculiar growth mode is due to a long-range repulsive interaction between molecules. The analysis of molecular-pair distributions obtained by scanning tunneling microscopy measurements permits us to determine that the nature of TTF intermolecular interactions on Au (111) is electrostatic. A repulsion between molecules is caused by the accumulation of charge due to electron donation into the metal surface, as pictured through density functional theory calculations

A functional non-central limit theorem for jump-diffusions with periodic coefficients driven by stable Levy-noise

We prove a functional non-central limit theorem for jump-diffusions with periodic coefficients driven by strictly stable Levy-processes with stability index bigger than one. The limit process turns out to be a strictly stable Levy process with an averaged jump-measure. Unlike in the situation where the diffusion is driven by Brownian motion, there is no drift related enhancement of diffusivity.Comment: Accepted to Journal of Theoretical Probabilit

Transbronchial catheter aspiration compared to forceps biopsy in the diagnosis of peripheral lung cancer

<p>Abstract</p> <p>Objective</p> <p>The usual procedure for obtaining material for histological analysis for the diagnosis of peripheral carcinoma of the lung is transbronchial forceps biopsy (TBB). Not widely spread is acquiring samples for cytological examination by transbronchial catheter aspiration (TBCA). Data were retrospectively collected to determine the diagnostic sensitivity of TBCA in comparison with TBB concerning malignancy.</p> <p>Methods</p> <p>We analysed the results of 51 consecutively examined patients (age 68.7 ± 8.8 yrs.) applying both methods. 48 of 51 peripheral lesions proved to be malignant, 34 of which measured > 3 cm in diameter and 14 ≤ 3 cm. Fluoroscopy provided guidance in biopsies for both techniques.</p> <p>Results</p> <p>The mean diameter of the lesion was 3.7 ± 1.5 cm. We were able to establish a correct diagnosis by TBCA in 36 of 48 patients with lung cancer, and in 21 of 48 patients by TBB (75% vs. 44%, p < 0.01, chi-square-test). By combination of both methods 39 of 48 patients were correctly diagnosed. For carcinoma > 3 cm the success rate for TBCA was 76% (26/34) and for TBB 56% (19/34). For carcinoma ≤ 3 cm the success rate for TBCA was 71% (10/14) and for TBB 14% (2/14).</p> <p>Conclusions</p> <p>Even in lesions ≤ 3 cm application of TBCA results in an only marginally lower success rate compared to lesions > 3 cm. Due to the overall high success rate we suggest to apply the easy-to-handle and inexpensive method of TBCA in diagnostic procedure of peripheral lung carcinoma.</p

Derivative moments in turbulent shear flows

We propose a generalized perspective on the behavior of high-order derivative moments in turbulent shear flows by taking account of the roles of small-scale intermittency and mean shear, in addition to the Reynolds number. Two asymptotic regimes are discussed with respect to shear effects. By these means, some existing disagreements on the Reynolds number dependence of derivative moments can be explained. That odd-order moments of transverse velocity derivatives tend not vanish as expected from elementary scaling considerations does not necessarily imply that small-scale anisotropy persists at all Reynolds numbers.Comment: 11 pages, 7 Postscript figure

Formation of dispersive hybrid bands at an organic-metal interface

An electronic band with quasi-one dimensional dispersion is found at the interface between a monolayer of a charge-transfer complex (TTF-TCNQ) and a Au(111) surface. Combined local spectroscopy and numerical calculations show that the band results from a complex mixing of metal and molecular states. The molecular layer folds the underlying metal states and mixes with them selectively, through the TTF component, giving rise to anisotropic hybrid bands. Our results suggest that, by tuning the components of such molecular layers, the dimensionality and dispersion of organic-metal interface states can be engineered