Inclusive and exclusive measurements in the projectile breakup of 7Li

The inclusive and exclusive measurements were carried out for ⁷Li projectile breakup on ²⁷Al target at 48 MeV. In the inclusive data we have observed a broad peak around the beam velocity for alphas and tritons. The exclusive data for alpha-triton coincidences show good agreement with the post-form DWBA theory of breakup reactions.     

Quasielastic reactions around the coulomb barrier in 16O+118Sn

Measurement of elastic and quasielastic reaction cross sections were done in ¹⁶O + ¹¹⁸Sn system at two different energies above the barrier. Attempts are being made to understand the results in the framework of coupled reaction channel model.     

Nuclear orbiting and anomalies in nuclear reactions

In this paper, we report our measurements of back-angle oxygen and carbon particle yields from ¹⁶O+⁸⁹Y, ¹²C+⁹³Nb reactions forming the same compound nucleus ¹⁰⁵Ag at the same excitation energy and spin distribution. We find anomalously large oxygen yield and entrance channel dependence at high excitation energies from ¹⁶O+⁸⁹Y reaction implying formation of a dinuclear orbiting complex. Possible connection between nuclear orbiting and fast fission is also discussed.     

An alternative approach to determine the spot-size of a multi-mode laser beam and its application to diode laser beams

An alternative approach is suggested to determine the spot-size of a multi-mode laser beam. It has been shown by simulations that the suggested approach can give the beam quality factor and characteristic radius with less than 5% error. Unlike the power content method, the proposed method is applicable to the beams even with diameter one tenth of the CCD size. The new approach has been applied to a multi-mode diode laser output and it is shown that the ABCD matrix analysis can be used for beam propagation, with the measured parameters of the laser.     

Remarkable enhancement of magnetization in the superconducting state of In/Ni nanoparticle composites by inhomogeneous spin anti-screening

The enzymatic hydrolysis of quinizarin diester in silica nanoparticle (NP) of 200 nm diameter is investigated by confocal fluorescence microscopy. The quinizarin diester substrate and the intermediate quinizarin monoester are non-fluorescent species and only the end product—quinizarin formed by enzymatic hydrolysis produces intense fluorescence of the silica NP. The enzyme activity of lipase adsorbed into silica NP was similar to that observed for lipase chemically bound to silica surface. In both situations, partial aggregation of the silica NP dispersed in thin film of polyvinylpyrrolidone was observed from fluorescence and scanning electron microscopy images. The fluorescence decay of the end product—quinizarin in silica NP was biexponential with decay times of 0.49 and 2.17 ns. These two decay times found are ascribed to quinizarin adsorbed in silica NP and dispersed in the surrounding medium, respectively.     

Electrically controllable metal–insulator-like transition in nanoparticle compacts

We report on the observations of tunneling transport in nanocompacts, where nanoparticles are packed into compact units using selective mass compositions and packing densities. An insulator-like thermal behavior in electron transport is seen in a very loosely packed 6-nm Ag nanocompact, whereas the densely packed 4.5-nm Au nanocompact displays a metal-like thermal behavior. Metal–insulator-like transitions, with the transition temperature can readily be tuned by controlling the bias voltage, are observed in the nanocompact consists of mixtures of 2.4 nm Ag and 4.8 nm core/shell Cu/Cu₂O nanoparticles. The resistivity across the metal–insulator transition is found to change by more than four orders-of-magnitude. At low bias voltages or small excitation currents, the metal–insulator transition occurs at ~190 K. The transition temperature can be tuned to reach the ambient temperature when a higher bias voltage or a larger current is allowed. Possible mechanisms that may produce the observed transport characteristics in the nanocompacts are discussed.