Increasing farm income by introducing fish culture in deepwater rice environment

Fish culture in deep-water-rice (DWR) environment using net pen and polder systems was evaluated. In net pen rohu and Thai silver barb were cultured, whereas a 5-species combination (rohu, mrigal, common carp, grass carp and Thai silver barb) were cultured with BR3 rice variety and DWR. Boro-fish production system produced 2.8 t/ha of fish and 7.33 t/ha of rice in polder system with 5-species combinations

Mono- and polyculture of silver barb (Puntius gonionotus) in deepwater rice systems in Bangladesh

Experiments with fish enclosures were conducted at the Deepwater Rice Farming Systems Research Site at Shuvullah, Mirzapur, Bangladesh. The objective was to study the performance of silver barb (Puntius gonionotus) called Thai sharputi or rajputi in Bangladesh in mono-and-polyculture with grass carp (Ctenopharyngodon idella), common carp (Cyprinus carpio), catla (Catla catla) and rohu (Labeo rohita). Each enclosure measured 21 m x 21 m with an approximate net height of 3.5 m. The stocking densities per cubic meter were 1 fingerling for Thai sharputi monoculture (enclosure 1), and 2 fingerlings for the polyculture systems (enclosure 2 and 3). The species ratio for enclosure 2 was 0.37:0.27:0.02:0.34 (grass carp:Thai sharputi:common carp:catla) and for enclosure 3, 0.4:0.4:0.2 (catla:rohu:Thai sharputi). In monoculture (enclosure 1), Thai sharputi performed well. This relatively good production was mainly attributed to the use of appropriately sized fingerlings and rapid growth from consumption of an abundant supply of azolla in addition to feed given. For the polyculture in enclosure 2, the average weight gain of common carp was the highest (673 g) followed by grass carp (475 g) and Thai sharputi (286 g). For the polyculture in enclosure 3, the length and weight gains for Thai sharputi were almost the same as for the monoculture

Synthesis and characterization of dielectric, electric, and magnetic properties of vanadium doped-bismuth europium ferrites for multiferroic applications

Polycrystalline Bi0.90Eu0.10Fe1-xVxO3 (BEFVO) (where x = 0.00 to 0.10) ceramics were synthesized by the solid-state reaction method. The X-ray diffraction (XRD) pattern revealed that all the samples possess hexagonal crystal structures with some impurity peaks. Gold Schmidt’s tolerance factor of the samples was found 0.8436 to 0.8478 which represents more stability of the doped BiFeO3 (BFO) than parent BFO. The crystallite size was found in the range of 65–33 nm. The density gradually increases with increasing the V concentration and the maximum bulk density (ρB = 6.981 g/cm3) is obtained for the x = 0.10 sample. The obtained average grain size is found in the micrometer range and the values are in the range of 1.31–0.74 µm. The maximum dielectric constant of 2577 at 102 Hz is found for the x = 0.07 sample. The resistivity decreases with doping concentration as a result of ac conductivity increases. The highest transition frequency of long-range to short-range mobility of charge carriers is obtained for the x = 0.07 sample. The highest real part of the initial permeability of 25.24 is found for x = 0.07 multiferroic ceramics. For the x = 0.07 sample, the maximal saturation magnetization is found to be 1.91 emu/g. The studied samples comprise large electric polarization and the optimum polarization of 7.5 μc/cm2 is observed for the x = 0.07 composition