Phantom Wormholes in (2+1)-Dimensions

In this paper, we have constructed a (2+1)-dimensional wormhole using inhomogeneous and anisotropic distribution of phantom energy. We have determined the exact form of the equation of state of phantom energy that supports the wormhole structure. Interestingly, this equation of state is linear but variable one and is dependent only on the radial parameter of the model.     

Lieb–Robinson Bounds for the Toda Lattice

We establish locality estimates, known as Lieb–Robinson bounds, for the Toda lattice. In contrast to harmonic models, the Lieb–Robinson velocity for these systems do depend on the initial condition. Our results also apply to the entire Toda as well as the Kac-van Moerbeke hierarchy. Under suitable assumptions, our methods also yield a finite velocity for certain perturbations of these systems.     

Recurrence tracking microscope based on magnetic mirrors

We present a recurrence tracking microscope (RTM) based on a magnetic mirror to probe micro and nanostructures on a surface. We modify existing RTM by introducing a magnetic mirror rather than the optical surface that produces exponentially decaying potential above the mirror surface in the vertical direction. Therefore, the cold atom evolves in a potential made up by the magnetic and gravitational fields. For a rapid decay of the magnetic field, the effective form of the potential becomes that of a triangular well. Hence, the coherent evolution of the atom above the magnetic trampoline reveals information on height and spacing between the surface structures. Presently available experimental technology makes it possible to develop the device in the laboratory.     

Routine determination of manganese in ores by INAA with an Am−Be neutron source. Application to manganese ore deposits in North-Western Nigeria

A 5 Ci Am–Be isotopic neutron source was used for the routine determination of manganase in ore samples. Concentration range was 0.1–35%, sample mass is about 17 g, irradiation time 6 h and cooling time 2 min. Counting was performed with a flat 3×3 NaI crystal for 1 h. For low concentrations, several aliquots are irradiated in identical positions around the source and combined. Standards of similar composition to that of the samples are made of KMnO₄, mixed with Fe₂O₃ and SiO₂. Corrections are applied for residual differences in neutron and -absorption.     

Determination of trace elements in Nigerian kola-nuts by instrumental neutron activation analysis

The trace elements content of Cola acuminata and three varieties of Cola nitida have been determined using neutron activation analysis. The samples have been irradiated at the Joint Universities Research Reactor, Risley, England for 7^1/2 hours in a neutron flux of 2.5·10¹² n·cm^–2s^–1 and analysed using high resolution lithium drifted germanium detector coupled to a Canberra 35 microprocessor as a 4096 channel gamma spectrometer. The elements: Na, K, Br, W, Fe, Cs, Co, Zn, and Sc were detected.     

Diverging stereochemical pathways in an intramolecular Diels-Alder reaction determined by dienophile structure

[reaction: see text] Intramolecular Diels-Alder cycloaddition of tolylsulfonyl alkynone 5a and vinyl ketone 19 led to single isomers with opposite diastereoselectivity. Decalin 20 incorporates the correct C(9)-C(11) stereochemical array for a projected synthesis of HMP-Y1 (1).     

The uptake of radioisotopes onto clays and other natural materials

Montmorillonite and illite clays were examined for their ability to take up cesium and strontium radioisotopes from solution. Uptakes onto near homoionic Na, Ca, Mg and Sr clays were assessed by distribution coefficients measured at different Na, Cs, Mg, Ca and Sr solution concentrations. Some experiments were carried out at different pH, and to check the effect of differing anions. In addition measurements of the uptake of ruthenium species were made.     

Effect of heat transfer on the peristaltic flow of an electrically conducting fluid in a porous space

This work is aimed at describing the heat transfer on the peristaltic motion in a porous space. An incompressible and magnetohydrodynamic (MHD) viscous fluid is taken in an asymmetrical channel. Expressions of dimensionless stream function and temperature are obtained analytically by employing long wavelength and low Reynolds number assumptions. The influence of various parameters of interest is seen through graphs on pumping and trapping phenomena and temperature profile.