Charge order suppression and antiferromagnetic to ferromagnetic switch over in Pr_0.5Ca_0.5MnO_3 nanowires

We have prepared crystalline nanowires (diameter ~ 50 nm, length ~ a few microns) of the charge ordering manganite Pr_0.5Ca_0.5Mn_O3 using a low reaction temperature hydrothermal method and characterized them using X-ray diffraction, transmission electron microscopy, SQUID magnetometry and electron magnetic resonance measurements. While the bulk sample shows a charge ordering transition at 245 K and an antiferromagnetic transition at 175 K, SQUID magnetometry and electron magnetic resonance experiments reveal that in the nanowires phase, a ferromagnetic transition occurs at ~ 105 K. Further, the antiferromagnetic transition disappears and the charge ordering transition is suppressed. This result is particularly significant since the charge order in Pr_0.5Ca_0.5MnO_3 is known to be very robust, magnetic fields as high as 27 T being needed to melt it.Comment: 12 pages including 4 figures. submitted to Applied Physics Letter

Pollution from fishmeal plant discharge at Mukka beach, north of Mangalore

Effluents from various industries are major source of pollutants in the coastal areas. The type and pollution and the impact magnitude of on coastal environment depends on the physical and chemical characteristics of the effluent, the mode of discharge and the hydrodynamics of the receiving body. While several chemical manufacturing industries produce toxic effluents which need special treatment and disposal, the process wastewater from fish/food processing units have high organic content which can be removed by simple methods

Occurrence of Parasitoid, Leiophron Sp. (Hymenoptera: Braconidae), on Adults of Helopeltis antonii Signoret in Cashew

Helopeltis antonii is a major pest of cashew, cocoa, neem, guava and pepper in the old world tropics. Survey for parasites identified a parasitoid, Leiophron sp. (Hymenoptera: Braconidae), on adults of H. antonii. The parasitism was low (1.3%), of which 59.4% was observed during the month of June. Size of the parasitoid larvae was 3.66 ± 0.11mm in length, and 1.31±0.03mm in breadth. Pre-pupation period was 1.75±0.22 days. Copulation was observed between parasitized H. antonii males and females indicating, that, mating was not affected by parasitism. Parasitoid activity showed significant positive correlation (r = 0.62; P = 0.05) with rainfall. Parasitism provided by this parasitoid certainly warrants further investigation on biological control of this economically important pest