Techno-commercial aspects of food irradiation in India

Research and development work has been carried out at Food Technology Division of Bhabha Atomic Research Center for more than past fifty years. After establishing potential commercial applications, a lot of time and efforts were spent on proving the wholesomeness and nutritional adequacy of irradiated foods. The first approval from health authorities came in 1994 for processing potato, onion and spices. Additional commodities were approved in 1998 and 2001, bringing the list of commodities to more than 20. Two technology demonstration plants were set up by the government, one for high dose applications like microbial decontamination of spices and dry vegetables in 2000, and another for low dose applications, like sprout inhibition and insect disinfestation, in 2003. In 2004, irradiation was approved as a quarantine measure. This enabled export of mango to USA after a gap of 18 years in 2007. More than a dozen plants have now been set up by private entrepreneurs in the country.     

Imidazole derivatives as the organic precursor of ZnO nano particle

N₁-Hydroxy-2,4,5-trisubstituted imidazoles were synthesized starting from 1,2-diketones. The crystal structure of 4,5-dimethyl-2-(3-nitrophenyl)-1H-imidazol-1-ol has been determined. An unusual intermolecular hydrogen bonding through the association of water molecule has been reported. These imidazole derivatives can be thought of as the organic precursor for the synthesis of zinc oxide nano particles.     

Density of states in the conduction band of some rare earth oxides

The results of a systematic investigation of the intensity distribution near the short wavelength limit of the continuous X-ray spectrum for the most common rare earth oxides are reported. Anomalies in the band structure of some oxides have been observed and are discussed in terms of localized energy levels in the forbidden band due to the existence of colour centres. This implies that the physical properties of pure compounds strongly depend on the precise experimental conditions of preparation.     

Phosphine-mediated [4 + 2] annulation of bis(enones): a Lewis base catalyzed "mock Diels-Alder" reaction

Lewis-base-catalyzed cycloisomerization of bis(enones) to decalins has been demonstrated as an alternative to the traditional Lewis acid catalyzed Diels-Alder cycloaddition. In this process, a trialkylphosphine mediates both bond formation steps in two distinct catalytic cycles. The single-pot operation generates two carbon-carbon bonds and up to five contiguous stereocenters in one step, starting from achiral, aliphatic substrates; eight examples are provided. [reaction: see text]     

1-(2-Iodophenyl)-1H-tetrazole as a ligand for Pd(II) catalyzed Heck reaction

1-(2-Iodophenyl)-1H-tetrazole 2 was synthesized by the reaction of 2-iodoaniline, sodium azide and triethyl orthoformate in acetic acid. The newly synthesized ligand 2 was successfully used in Heck reaction to give the cross-coupled products in excellent yields.     

Resonant tunneling of ultracold atoms through vacuum induced potentials

We demonstrate resonant tunneling of ultracold atoms through potentials produced by the interaction of atoms with the vacuum field of a system of cavities. We show the close connection of the transmission characteristics to the resonant states in vacuum induced potentials. Transmission of cold atoms, though sharing some features with tunneling in finite semiconductor superlattices, is strongly dependent on the coherent addition of amplitudes from various wells and barriers.     

Polarity switching and transient responses in single nanotube nanofluidic transistors

We report the integration of inorganic nanotubes into metal-oxide-solution field effect transistors (FETs) which exhibit rapid field effect modulation of ionic conductance. Surface functionalization, analogous to doping in semiconductors, can switch the nanofluidic transistors from p-type to ambipolar and n-type field effect transistors. Transient study reveals the kinetics of field effect modulation is controlled by ion-exchange step. Nanofluidic FETs have potential implications in subfemtoliter analytical technology and large-scale nanofluidic integration.