Formation of nanoscale aggregates of a coumarin derivative in Langmuir–Blodgett film

In the present communication, we report the formation of organized nanoscale aggregates of a coumarin derivative 7 Hydroxy-N-Octadecyl Coumarin-3-Carboxamide (7HNO3C) at the air–water interface and in Langmuir–Blodgett (LB) films in the presence and absence of stearic acid (SA). A pressure-area isotherm reveals that the 7HNO3C form stable monolayer at the air–water interface. However, the stability can be improved by mixing it with a fatty acid stearic acid (SA). The miscibility study shows that the nature of interaction is strongly dependent on the mixing ratio and surface pressure. At a mole fraction of 0.4 of 7HNO3C in SA, the attractive and repulsive interaction between these two molecules balance each other forming a stable film with nanoscale aggregates. UV-Vis absorption spectroscopic studies reveal the nature of the aggregates in LB films. Scanning electron microscopy gives compelling visual evidence of formation of nanoscale aggregates in the mixed LB films.     

SU(2N f) ⊗O(3) light diquark symmetry and current-induced heavy baryon transition form factors

We study the current-induced bottom baryon to charm baryon transitions in the Heavy Quark Symmetry limit asm _q→∞. Our discussion involvess-wave tos-wave as well ass-wave top-wave transitions. Using a constituent quark model picture for the light diquark system with an underlyingSU(2N _f)?O(3) symmetry and the heavy quark symmetry we arrive at a number of new predictions for the reduced form factors that describe these transitions.     

Some best approximation results in locally convex spaces

In this note we obtain generalization of well known results of carbone and Conti, Sehgal and Singh and Tanimoto concerning the existence of best approximation and simultaneous best approximation of continuous funcitons from the set up of a normed space to the case of a Hausdorff locally convex space.     

Non-commutative geometry and supersymmetry

A direct correspondence between supersymmetric models and a recently proposed field theory based on non-commutative geometry is established.     

SU (2N f) ⊗ O(3) light diquark symmetry and current-induced heavy baryon transition form factors

We study the current-induced bottom baryon to charm baryon transitions in the Heavy Quark Symmetry limit as m_q → ∞. Our discussion involves s-wave to s-wave as well as s-wave to p-wave transitions. Using a constituent quark model picture for the light diquark system with an underlying SU (2N_f) ? O(3) symmetry and the heavy quark symmetry we arrive at a number of new predictions for the reduced form factors that describe these transitions.     

Angular-dependent XPS valence-band spectra from single-crystal copper

High-resolution angular-dependent X-ray photoemission (XPS) valence-band spectra from a copper single crystal with (001) orientation are presented and analyzed in terms of a direct-transition model of photoemission. This model includes the effects of photon momentum, spectrometer geometry, and, for very low angles of emission, refraction of electrons in leaving the surface, but neglects matrix-element variation. Theoretical calculations are found to be in good agreement with experiment for six distinct emission directions. For low (grazing) angles of emission, a sharpening of the d-band peak is observed that may be associated with surface-specific band-structure changes.     

Fluctuations in the total cross sections of Y,Zr, La,Ce, Pr,Gd, Ho,Ta and Hg for 1.0 TO 2.0 MeV neutrons

Results of an analysis of the fluctuations observed in the neutron total cross sections of nine different nuclei in the energy range between 1.0 and 2.0 MeV are presented. It has been found that in general these may be explained to be due to fluctuations in the widths and spacings of the compound-nucleus level. The cross section data for some of the nuclei seem to indicate the presence of structures with widths much larger than the compound-nucleus width.