Density operator description of geometric phenomena in the ray space

A general gauge-invariant formalism for parallel transport, geodesics and geometric phase based on the pure state density operator is propounded. A single-query quantum search algorithm is proposed.     

Evaluation of transfer factor and ecological half life of 137Cs in terrestrial matrices around Kakrapar Gujarat Site,India during 1993–2019

Journal of Radioanalytical and Nuclear Chemistry - The activity of 137Cs was measured in different terrestrial samples around Kakrapar Gujarat site. Transfer Factor and Ecological half-life of...     

Silica-supported perchloric acid (HClO<Subscript>4</Subscript>/SiO<Subscript>2</Subscript>) as efficient catalyst for the synthesis of tetraazamacrocyclic complexes of transition metals

Silica-supported perchloric acid (HClO₄/SiO₂) was used to catalyze the synthesis of tetraazamacrocyclic complexes of Co(II), Ni(II), Cu(II), and Zn(II) from the corresponding metal chlorides, nitrates, or acetates, isatin, and benzene-1,2-diamine in ethanol. The use of HClO₄/SiO₂ as catalyst allowed the reaction to be performed under stirring at room temperature instead of traditional reflux and completed in two hours. The synthesized complexes were characterized by molar conductance and magnetic susceptibility measurements, IR, electronic, ¹H NMR, and mass spectra, and thermogravimetric and X-ray powder analyses. On the basis of these data, six-coordinate octahedral geometry was proposed for all complexes. The synthesized complexes were also tested for antimicrobial activity.     

Efficient Microwave‐assisted One‐pot Synthesis of Novel Spironaphthopyrano‐one Derivatives

Rapid and efficient one‐pot three‐component synthesis of new spironaphthopyrano‐one derivatives by cyclocondensation reaction in aqueous media is achieved under microwave irradiation conditions. This protocol has the advantages of higher yield, lower cost, reduced time, environmental impact, and convenient procedure.     

Pancharatnam geometric phase originating from successive partial projections

The spin of a polarized neutron beam subjected to a partial projection in another direction, traces a geodesic arc in the 2-sphere ray space. We delineate the geometric phase resulting from two successive partial projections on a general quantal state and derive the direction and strength of the third partial projection that would close the geodesic triangle. The constraint for the three successive partial projections to be identically equivalent to a net spin rotation regardless of the initial state, is derived.      

A green function approach to shear viscosity coefficient

Modified transport equations are derived from Kadanoff and Baym kinetic equations, suitable for the study of thermal transport coefficients. These equations include the Hartree average energy term which has been ignored in the previous studies of thermal transport coefficients. They are linearised and the successive perturbation method is employed to solve them. The solutions are applied to shear viscosity coefficient of gases and the results are compared with the recent experimental measurements for several complex and simple gases. The potential assumed is a hard core one with a perturbation tail. The agreements are particularly good for gases with low molecular weight and in the high temperature range. For complex molecules even in the low temperature range, the agreement is better than the previous calculations. The formula derived yields the explicit temperature dependence of the viscosity coefficient.     

Interfering with the neutron spin

Charge neutrality, a spin 1/2 and an associated magnetic moment of the neutron make it an ideal probe of quantal spinor evolutions. Polarized neutron interferometry in magnetic field Hamiltonians has thus scored several firsts such as direct verification of Pauli anticommutation, experimental separation of geometric and dynamical phases and observation of non-cyclic amplitudes and phases. This paper provides a flavour of the physics learnt from such experiments.     

Effect of ion implantation on the refractive index of glass

Studies on the changes of the index of refraction in glass due to ion implantation provide an insight into the structure of amorphous substances, besides being important for the development of techniques for the production of optical integrated circuits. Using a heavy ion accelerator, optically flat samples of Pyrex and Corning borosilicate glass were implanted with ions of gallium and argon at various incident energies and doses. The refractive index was then measured and found to be between 1.5 and 1.8 at a wavelength of 5893 A.U. The change in the refractive index was found to vary linearly with the incident dose irrespective of the ion species. This suggests that bombardment damage is mainly responsible for the effect. The dependence of the refractive index change on the incident dose however depends strongly on the chemical composition of the substrate glass.