Recovery of Stresses in a Beam from those in a Cone

We consider a trapezoidal thin plate, as shown in Figure 1, which has one end loaded by a concentrated transverse unit force and the other clamped at zero displacement. The stress is determined according to a method proposed by Galerkin [1] which involves the superposition of two plane elastic stress distributions. To access the accuracy of the method, the oblique sides of the trapezium are allowed to become parallel so that, in the limit, the trapezium becomes a rectangle of the same area. The limiting values of the maximum stress components are exactly those obtained by the Saint-Venant method for a bar. However, over the clamped end, the displacement vanishes only at three arbitrarily selected points. A similar procedure is applied to the transversely loaded truncated cone, but now the limiting values of the stress do not entirely match those obtained by the Saint-Venant theory for a circular cylinder. We also briefly discuss, for completeness, the same bodies under axial loadings, and arrive at similar conclusions which therefore hold for general loads. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis of gold nanoparticles using herbal Acorus calamus rhizome extract and coating on cotton fabric for antibacterial and UV blocking applications

Gold nanoparticles (AuNPs) have been synthesized by greener method using chloroauric acid as precursor and extract of Acorus calamus rhizome as reducing agent. Formation of AuNP was confirmed by the presence of Surface Plasmon Resonance (SPR) peak in UV–Visible spectral analysis. XRD and FT-IR spectral analyses were performed for characterization. SEM images show spherical morphology and HR-TEM images reveal nanosize of AuNPs. The AuNPs were then coated on cotton fabric by pad-dry-cure method and characterized by SEM with EDAX technique. The results reveal the deposition of AuNPs on the surface of cotton fabric. Uncoated cotton, neat extract coated cotton and extract containing AuNPs coated cotton fabrics were then tested for antibacterial activity against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacterial strains by AATCC 100 test method. It showed that the extract containing AuNPs coated cotton fabric had higher antibacterial activity than other test samples against E. coli. UV-DRS analysis performed on extract containing AuNPs coated cotton fabric showed improved UV-blocking property than uncoated cotton fabric and neat extract coated cotton fabric.     

On partial weakly clustering states with an application to the Ising model

The concept of partial weak clustering in the mean is defined for states on physical systems which admit amenable (semi-)groups of symmetries. The properties of partial weak clustering states are studied and the relations between these states and (extremal) invariant (partial) states are considered. As an application we discuss the zero field magnetization in the two-dimensional Ising model.     

On universal relations in elasticity theory

Zusammenfassung Es wird eine Methode zur Erhaltung allgemeingültiger Beziehungen für Verzerrungen kompressibler, isotroper, elastischer Körper dargestellt.     

Renormalization connection between the eight-vertex model and the gaussian model

A generalized version of the Villain model is defined which contains the eight-vertex model as a special case. A renormalization pattern is formulated in terms of this Villain model by which critical line(s) in the eight-vertex model are connected with the Gaussian fixed line. Gaussian equivalents are found for various operators along the Baxter line. The relation between the present results and those recently obtained by Kadanoff and Brown is discussed.     

Asymptotic behaviour of solutions to the equation of constant mean curvature on a three-dimensional region

A first order differential inequality is derived for the cross-sectional energy flux of the solution to the equation of constant mean curvature defined on a three-dimensional prismatic cylinder of convex cross-section. Integration of the inequality yields estimates which are employed to prove for large values of the axial variable that the solution in measure either grows at least algebraically or decays at most exponentially to the lower dimensional cross-sectional solution. This result generalises that previously obtained by the authors for the corresponding two-dimensional problem.

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Sommario Si dimostra una disequazione differenziale del primo ordine per il flusso di energia attraverso la sezione trasversale della soluzione dell' equazione della curvatura media costante definita in un cilindro prismatico tridimensionale a sezione trasversale convessa. L'integrazione della disuguaglianza fornisce stime che sono impiegate a provare che, per grandi valori della variabile assiale la soluzione in misura o cresce almeno algebricamente o decade al più esponenzialmente alla soluzione per la sezione trasversale più piccola. Questo risultato generalizza quello ottenuto in precedenza dagli autori per il corrispondente problema bidimensionale.

     

An Approximate Treatment of Blunt Body Impact

This paper considers a blunt body, modelled by an elastic-perfectly plastic one-dimensional bar, impacting normally against a rigid fixed target as indicated in Figure 1. When the impact velocity is small, the bar behaves elastically during the ensuing motion and rebounds with an equal and opposite velocity to that on impact. But for large impact velocity, part of the bar adjacent to the point of contact experiences permanent plastic deformation reducing the rebound velocity. The illuminating theory developed by Taylor [10] analyzed the impact of a rigid-plastic bar. We extend this treatment by employing a semi-inverse procedure combined with energy conservation to additionally take into account elastic deformation.     

Siderophore-Mediated Iron Uptake Promotes Yeast–Bacterial Symbiosis

In the present study, siderophore produced by the marine yeast Aureobasidium pullulans was characterized as hydroxamate by chemical and bioassays. The hydroxamate assignment was supported by the appearance of peaks at 1,647.21?C1,625.99?cm^?1 and at 1,435.04?cm^?1 in the infrared spectrum. The purified siderophore exhibited specific growth-promoting activity under iron-limited conditions for siderophore auxotrophic probiotic bacteria. Cross-utilization of siderophore indicates a symbiotic relationship between the yeast A. pullulans and the selected probiotic bacterial strains. Statistical optimization of medium components for improved siderophore production in A. pullulans was depicted by response surface methodology. The shift in UV?CVis spectroscopy indicates the photoreactive property and subsequent oxidative cleavage of purified siderophore on exposure to sunlight.