ISO-spin centroids for single-nucleon transfer reactions involving mutli-shell target states

In single nucleon transfer reactions, involving multi-shell targets equations relating the isospin centroid (defined as J-averages of the energy weighted strengths) to the nature of the residual interaction and to the quantum numbers of the target state, have been derived.     

Laminar plane jet in a gas medium

The effects of compressibility on a laminar plane jet are investigated. First, assuming that the viscosity is directly proportional to the enthalpy it is found that the similarity solutions both for momentum and energy equations exist. By a proper transformation of the similarity variable, the energy equation, in the case of viscous heating, is reduced to a hypergeometric equation and solutions for arbitrary Prandtl number are obtained. Secondly, taking the Prandtl number of the fluid as unity and a power law for the dependence of viscosity on enthalpy the velocity distribution is obtained with the help of Crocco's integral.

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Zusammenfassung Der Einfluss der Kompressibilität auf einer ebenen laminaren Strahl wird untersucht. Zunächst wird unter der Annahme, dass Zähigkeit und Enthalpie einander proportional sind, gefunden, dass sowohl die Impulsgleichung als auch die Energiegleichung Aehnlichkeitslösungen haben. Im Falle der Erwärmung durch Dissipation wird die Energiegleichung durch eine geeignete Transformation der Aehnlichkeitsvariablen auf eine hypergeometrische Differentialgleichung reduziert, und Lösungen für beliebige Prandtl-Zahlen werden bestimmt. Im Falle, dass zwischen Zähigkeit und Enthalpie ein Potenzgesetz herrscht, wird für die Prandtl-Zahl1 die Geschwindigkeitsverteilung mit Hilfe von Crocco's Integral erhalten.

     

Two novel cassane diterpenoids from Acacia jacquemontii

The structure of two new diterpenoids (1 and 3), both of which contain the unique feature of a 7-membered hemiacetal ring B, have been established from chemical and spectroscopic (especially NMR) evidence. Single crystal X-ray crystallographic analysis of 1 has confirmed the structure and allowed the relative stereochemistry to be determined.     

Symmetry adapted functions belonging to the dirac groups

An earlier analysis of the canonical form of a pair of invertible operators obeying the exchange rule is extended to cover a set of operators, between each pair of which a relation of this type exists; and for which a power of each operator is the unit matrix. Such relations define a system which may be regarded as a generalization of the Dirac matrices of relativistic quantum mechanics. We concentrate upon the group theoretic aspects of such a system and its matrix representations. Applications arise from the fact that all projective representations of finite abelian groups take the form of a Dirac Group. In particular, the representations of the magnetic space groups, which are projective representations of the lattice groups, arise in this manner.     

Effect of chemical binding energy on the dynamics of water

The calculated value of γ₁₁, a neutron-condensed system energy observable, using the recent neutron scattering kernel proposed by the authors which incorporates explicitly chemical binding amongst the water molecules, turns out to be in much better agreement with the experimental result than that given by the widely used Nelkin kernel. Low energy collective oscillations, thus, play an important role in the dynamics of water.     

Biocompatibility of gold nanoparticles and their endocytotic fate inside the cellular compartment: a microscopic overview

Macrophages are one of the principal immune effector cells that play essential roles as secretory, phagocytic, and antigen-presenting cells in the immune system. In this study, we address the issue of cytotoxicity and immunogenic effects of gold nanoparticles on RAW264.7 macrophage cells. The cytotoxicity of gold nanoparticles has been correlated with a detailed study of their endocytotic uptake using various microscopy tools such as atomic force microscopy (AFM), confocal-laser-scanning microscopy (CFLSM), and transmission electron microscopy (TEM). Our findings suggest that Au(0) nanoparticles are not cytotoxic, reduce the production of reactive oxygen and nitrite species, and do not elicit secretion of proinflammatory cytokines TNF-alpha and IL1-beta, making them suitable candidates for nanomedicine. AFM measurements suggest that gold nanoparticles are internalized inside the cell via a mechanism involving pinocytosis, while CFLSM and TEM studies indicate their internalization in lysosomal bodies arranged in perinuclear fashion. Our studies thus underline the noncytotoxic, nonimmunogenic, and biocompatible properties of gold nanoparticles with the potential for application in nanoimmunology, nanomedicine, and nanobiotechnology.     

Scaling relation for determining the critical threshold for continuum percolation of overlapping discs of two sizes

We study continuum percolation of overlapping circular discs of two sizes. We propose a phenomenological scaling equation for the increase in the effective size of the larger discs due to the presence of the smaller discs. The critical percolation threshold as a function of the ratio of sizes of discs, for different values of the relative areal densities of two discs, can be described in terms of a scaling function of only one variable. The recent accurate Monte Carlo estimates of critical threshold by Quintanilla and Ziff [Phys. Rev. E76, 051115 (2007)] are in very good agreement with the proposed scaling relation.