Hydrography of the Andaman sea during late Winter

179-189Distributions of temperature, salinity, density and dissolved oxygen during late winter in the Andaman Sea are presented by series of vertical sections and spatial distribution charts; study of the field of motion on dynamic computations is also included. Surface temperature exceeds 28°C over most of the northern Andaman Sea. Surface salinity increases from 31.0% in the northern regions to 32.8% in the southern regions. Density distribution in the upper 50 m is primarily controlled by the salinity distribution. Below the sill depth (1300 m), the water mass is characterized by uniform values of temperature, salinity and dissolved oxygen. Geostrophic circulation in the upper layer indicates the formation of cells (100-200 km), and the upper layer dynamics seem to be governed by the fresh water discharge into the region

Preparation and Characterization of Nano-Dy 2

Composite polymer electrolyte films containing various concentrations of nano-Dy2O3 (1.0 to 4.0%) in PVA + sodium citrate (90 : 10) are synthesized adopting solution cast method and are characterized using FTIR, XRD, SEM, and DSC techniques. The investigations indicate that all components are homogenously dispersed. Films containing 3% of nano-Dy2O3 are more homogenous and less crystalline, and the same is supported by DSC studies indicating the friendly nature to ionic conductivity. Transference number studies reveal that the major charge carriers are ions. With the increase in % of nano-Dy2O3, the conductivity increases and reaches maximum in 3% film with a value of 1.06 × 10−4 S/cm (at 303 K). Further, the conductivity of the film increases with raise in temperature due to the hopping of interchain and intrachain ion movements and fall in microscopic viscosity at the matrix interface of the film. Electrochemical cells are fabricated using these films with the configuration “anode (Mg + MgSO4)/[PVA (90%) + Na3C6H5O7 (10%) + (1–4% nano-Dy2O3)]/cathode (I2 + C + electrolyte),” and various discharge characteristics are evaluated. With 3% nano-Dy2O3 film, the maximum discharge time of 118 hrs with open-circuit voltage of 2.68 V, power density of 0.91 W/kg, and energy density of 107.5 Wh/kg are observed. These findings reflect the successful adoption of the developed polymer electrolyte films in electrochemical cells

Genetic diversity assessment using RAPD primers in insecticide resistant populations of diamondback moth Plutella xylostella (Linn.)

Genetic diversity in acephate, spinosad and Cry2Ab resistant Plutella xylostella collected from three states of India was assessed by RAPD markers. The DNA extracted from larvae was subjected to polymerase chain reaction using 10 RAPD primers. The highest number alleles (7) were produced by primer ABA-13, followed by six alleles each by primers ABA-2, 7, 8, 11, 14; five alleles each were produced by ABA-4, 9, 10, 12. UPGMA analysis clustered the acephate, spinosad and Cry2Ab treated P.xylostella populations into two groups with overall similarity level of 33%, 27% and 34% respectively. Cluster A consisted 11 samples while Cluster B consisted only F1 of acephate and spinosad treated Karnataka population. In Cry2Ab treated population Cluster B comprised 11 samples and Cluster A had out grouped singly i.e. F0 generation from Karnataka. The genetic variability between the acephate, spinosad and Cry2Ab treated populations ranged from 33 to 69%, 27 to 56% and 34 to 69% respectively. Acephate and spinosad treated F1 population and Cry2Ab treated F0 population from Karnataka were out grouped from rest of the populations

Assessment of insecticides and Cry2AB toxin resistance development in Karnataka population of Plutella xylostella (Linn.)

Insecticidal resistance studies against third instar larvae of DBM (Plutella xylostella L.) were carried out to know the rate of development of resistance from F1 to F3 generations in Karnataka population. The third instar larvae obtained from field were subjected to bioassay studies with tested against acephate, cypermethrin, spinosad, cartap hydrochloride and Cry2Ab toxin using leaf dip method to calculate LC50 values. The LC50 values of the insecticides were further used to quantify the resistance in P. xylostella of parental generation (F0) from Karnataka field population. The survivals from F0 generation were reared to next generation (F1). Resistance development studies was assessed from F1 to F3 generation with third instar larvae in every generation with a concentration that caused 80.00 % mortality for all the test insecticides and Cry2Ab toxin. Results revealed that ((0.17 folds) no resistance was developed against acephate in F3 generation. In case of cypermethrin 2.33 folds. Resistance studies further revealed that 1.50 folds resistance was developed against spinosad, 2.28 folds against cartap hydrochloride and Cry2Ab toxin 1.49 folds resistance was recorded in F3 generation. The rate of development of resistance from F1 to F3 generations increased in all the test insecticides and Cry toxin, except against acephate in Karnataka population. This data will be useful in the development of insecticide resistance management approach for DBM

Supercontinuum Generation in a Silicon Nanowire Embedded Photonic Crystal Fiber for Optical Coherence Tomography Applications

KSN wishes to thank CSIR [No: 03(1264)/12/EMR-11] and DST [No: SR/FTP/PS-66/2009], Government of India, for the financial support through the project.Postprin

Status of brackishwater prawn farming in Andhra Pradesh

Andhra Pradesh is estimated to have 762.51 ha of brackishwater area under prawn culture- Prawn culture In brackishwater ponds as well as in paddy fields converted into prawn ponds is picking up fast In the coastal districts of Andhra Pradesh, especially in East Godavari, Krishna and Guntur districts. There are more than 200 ha of brackishwater areas suitable for prawn culture in West Godavari district alone. IVIore and more are being brought under prawn farming in this district. Seml-lntensive culture technology is employed by the fish farmers. The average yield Is estimated at 450 kg/ha/crop. This paper presents and discusses the status of prawn culture in Andhra Pradesh, identifies the constraints and suggests strategies for bringing the abundantly available brackishwater areas under scientific prawn culture to Increase the yield from these ponds

Economic analysis of prawn culture in Andhra Pradesh - Some preliminary findings

Inadaquate supply of quality seed is one of the chief constraints that impedes the quick development of ptawn culture. Estuaries still remain the largest source of prawn seed supply. They are likely to remain so atleast for sometime in offing before the hatchery production of seeds is undertaken commercially and massively. The Marine Products Export development Authority assists the prawn farmers in setting up prawn seed banks by providing technical assistance on prawn culture, undertaking site selection and farm surveys, preparing project reports for submitting to the banks to get financial assistance, releasing subsidy to the tune of 16% on the capital cost of the project and providing continued technical assistance throughout the culture period. Already some prawn farmers have started establishing such prawn seed banks and supplying prawn seed commercially. This paper presents and discusses results of case studies on the economic feasibility of setting up prawn seed banks by fish farmers/prawn farmers

Extension service for prawn farming

The technology of prawn culture in India is still traditional and extensive called trapping-cum-holding in brackish water ponds, but adoption of Improved extensive prawn culture technology Is claimed to be picking up fast In several places notably In West Bengal, Kerala, Andhra Pradesh and Orissa. The production from such culture practices is estimated at 15000-17000 tons/year, accounting for about 5% of the total prawn production In India the technology of scientific prawn culture is now available. Though steps are being taken to motivate, and encourage the fish farmers to take up prawn culture on scientific lines to increase their Income, lack of an appropriate extension network Is felt to be a major handicap In the field. This paper attempts to review the various extension services available for taking up prawn culture by the fish farmers. Identifies the pitfalls and proposes a working fisheries extension programme for prawn culture In Indi

Nano-Pr 2

Varying concentrations of nano-Pr2O3 doped in “PVA + Sodium Citrate (90 : 10)” polyelectrolyte films are synthesized using solution cast technique and the films are characterized adopting FTIR, XRD, SEM, and DSC methods. The film with 3.0% of nano-Pr2O3 content is more homogenous and possesses more amorphous region that facilitate the deeper penetration of nanoparticles into the film causing more interactions between the functional groups of the polymeric film and nano-Pr2O3 particles and thereby turning the film more friendlily to the proton conductivity. The conductivity is maximum of 7 × 10−4 S/cm at room temperature for 3.0% nano-Pr2O3 film and at that composition, the activation energy and crystallinity are low. With increase in temperature, the conductivity is increasing and it is attributed to the hopping of interchain and intrachain ion movements and furthermore decrease in microscopic viscosity of the films. The major charge carriers are ions and not electrons. These films are incorporated successfully as polyelectrolytes in electrochemical cells which are evaluated for their discharge characteristics. It is found that the discharge time is maximum of 140 hrs with open circuit voltage of 1.78 V for film containing 3% of nano-Pr2O3 and this reflects its adoptability in the solid-state battery applications