Wall-bounded turbulent shear flow:Analytic result for a universal amplitude

In the turbulent boundary layer above a flat plate, the velocity profile is known to have the form v =v0[(1/κ)ln z+const]. The distance from the wall in dimensionless units is z and v0 is a uniquely defined velocity scale. The number κ is universal, and measurements over several decades have shown that it is nearly 0.42. We use a randomly stirred model of turbulence to derive the above law and find κ=√108/125π≃0.52

Lyoluminescence:a theoretical approach

When strongly energized halide or organic crystals are dissolved in a liquid solvent (like water), light is emitted as a result of a recombination process. This phenomenon is called lyoluminescence. The emitted light intensity, called the lyoluminescent intensity, depends on a class of factors like radiation dose, probability of radiative recombination, rate of dissolution in the solvent, etc. Combining some of these numerous effects we develop a nonlinear differential equation and analyze it by a dynamical system analysis as well as by exact numerical integration. The corresponding plot of the theoretical lyoluminescent intensity versus time graph, called the glow curve (Fig. (1)), matches very well with the shape of the experimental curve (Fig. (2)) for a vast range of characteristic values of the controlling parameters. ©2000 The American Physical Society

The Non-local Kardar-Parisi-Zhang Equation With Spatially Correlated Noise

The effects of spatially correlated noise on a phenomenological equation equivalent to a non-local version of the Kardar-Parisi-Zhang equation are studied via the dynamic renormalization group (DRG) techniques. The correlated noise coupled with the long ranged nature of interactions prove the existence of different phases in different regimes, giving rise to a range of roughness exponents defined by their corresponding critical dimensions. Finally self-consistent mode analysis is employed to compare the non-KPZ exponents obtained as a result of the long range -long range interactions with the DRG results.Comment: Plain Latex, 10 pages, 2 figures in one ps fil

Coupled non-equilibrium growth equations: Self-consistent mode coupling using vertex renormalization

We find that studying the simplest of the coupled non-equilibrium growth equations of Barabasi by self-consistent mode coupling requires the use of dressed vertices. Using the vertex renormalization, we find a roughness exponent which already in the leading order is quite close to the numerical value.Comment: 7 pages, 3 figure

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

Non-equilibrium growth for a restricted-curvature model

Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Non-equilibrium growth for a restricted-curvature model

Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal