Phase synchronization in an array of driven Josephson junctions

We consider an array of N Josephson junctions connected in parallel and explore the condition for chaotic synchronization. It is found that the outer junctions can be synchronized while they remain uncorrelated to the inner ones when an external biasing is applied. The stability of the solution is found out for the outer junctions in the synchronization manifold. Symmetry considerations lead to a situation wherein the inner junctions can synchronize for certain values of parameter. In the presence of a phase difference between the applied fields, all the junctions exhibit phase synchronization. It is also found that chaotic motion changes to periodic in the presence of phase differences.Comment: 13 pages, 6 figures, accepted for publication in "CHAOS

Course Manual: International Workshop-cum-Training Programme on "Fisheries and Aquaculture"

Marine fisheries contribute to food, nutrition, employment and income generation in India. The sector supports about four million people for their livelihood and nearly one million fishermen by way of employment and contributes significantly to the export earnings of the country and balance of trade. The sector contributes to an economic wealth valued at nearly US$10 billion annually. The marine fisheries of the country consist of small-scale and artisanal fishers belonging mechanized, motorized and non-mechanized sectors and a range of other stakeholders, including governmental and nongovernmental agencies. Though India is not a leading producer in true mariculture we are second in aquaculture production after China. Coastal aquaculture of shrimp has a major role in aquaculture production and export in India. Even though there is vast scope, recently only India has taken up mariculture technologies to the stake holder level. Due to the success achieved mariculture, it has been identified as a potential source of production enhancement for high valued species like lobster, seabass, cobia and pompano for which the capture fishery is negligible

Creation and annihilation of fluxons in ac-driven semi-annular Josephson junction

The dynamical behavior of a fluxon in a semi-annular long Josephson junction in the presence of an ac-drive is studied. The non-uniformity due to the non uniform distribution of bias current is investigated. The oscillating potential is found to increase the depinning current. Finite difference method is used for numerical analysis and the response of the system to the ac-bias is studied. The creation and annihilation of fluxon is also demonstrated numerically for the first, second and third Zero-Field step cases.Comment: 10 pages 8 figure

Total factor productivity growth of trawl fishing in Kerala state, India

Trawlers are the prominent fishing units in the mechanized fishing sector of Kerala state in the south west coast of India contributing 40% of the landings. The trawl catch in the state declined from 0.27 million tonnes in 1997 to 0.21 million tonnes in 2015. Increase in fishing power of trawlers with expansion in engine, gear capacities and overall length resulted in extending fishing trips from singleday to multiday and diversification of species caught. The paper discusses the technological changes and its impacts on sustainability of trawl operations in Kerala for the period 1997 to 2015 using total factor productivity analysis. The capacity of engines increased from 90hp to 550 hp during 1997- 2015 resulting in increased use of fuel in the fishing sector. There was fivefold increase in diesel cost and eight fold increase in ice cost in absolute terms when compared to less than two fold increase in average fish price during 1997-2015. The total factor productivity analysis revealed negative growth during 1997-2015 indicating that technological change has resulted in economic unsustainability in the production system

Evolution of electromagnetic and Dirac perturbations around a black hole in Horava gravity

The evolution of electromagnetic and Dirac perturbations in the spacetime geometry of Kehagias-Sfetsos(KS) black hole in the deformed Horava-Lifshitz(HL) gravity is investigated and the associated quasinormal modes are evaluated using time domain integration and WKB methods. We find a considerable deviation in the nature of field evolution in HL theory from that in the Schwarzschild spacetime and QNMs region extends over a longer time in HL theory before the power-law tail decay begins. The dependence of the field evolution on the HL parameter $\alpha$ are studied. In the time domain picture we find that the length of QNM region increases with $\alpha$. But the late time decay of field follows the same power-law tail behavior as in the case of Schwarzschild black hole.Comment: The article was fully rewritten, references added, to appear in MPL

Assessment of prevalence and risk factors of pre-eclampsia and eclampsia in tertiary care hospital

Background: Pre-eclampsia and eclampsia are two conditions in which high blood pressure essentially complicates pregnancy by causing oedema and/or albuminuria. The present study was undertaken among pregnant women to determine the prevalence of pre-eclampsia and eclampsia as well as to assess the association between risk factors and pre-eclampsia, risk factors and eclampsia and to determine the complications of pre-eclampsia and eclampsia. Method: A prospective observational study was conducted over a period of six months at obstetrics inpatient department of Basaveshwara Medical college and hospital, Chitradurga. Results: Total of 583 pregnant women who visited the inpatient department were enrolled, out of which study showed that the prevalence of pre-eclampsia was 91 (15.67%) and eclampsia was 54 (9.26%). A statistically varied significance level of p=0.00001 to 0.05 for risk factors such as age, primigravida, birth interval, pre-existing disease, placental abnormalities, multiple pregnancy, past history, proteinuria were found to be associated with pre-eclampsia and eclampsia. The complications such as pre-term birth, neonatal death HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets), Foetal growth restriction were found. Out of which pre-term birth was the most observed complication in both pre-eclampsia and eclampsia. Conclusions: Considering the significant association between the risk factors and pre-eclampsia, eclampsia from the study we conclude that early diagnosis is essential. Lack of antenatal care, limited access to medical facility and lack of resources have influenced in late diagnosis in our set up. As evidenced by study proper awareness should be provided to the pregnant women

Economic sustainability of marine fisheries in India: A total factor productivity approach

Marine fisheries sector of India has transformed from the status of subsistence fishery to that of multibillion dollar industry with the technological advancements in harvesting and post-harvest operations. Intensive shrimp trawling with multi-day fishing trips, introduction of purse seines in the late eighties and enhancement of overall fishing effort have resulted in declining catch per unit effort of different fishing units. The declining catch rates of high value fishes will have a serious impact on the economic sustainability of marine fisheries sector and livelihood security of fisher folk. The objective of the study was to assess the performance and economic sustainability of marine fish production in India by using total factor productivity growth for the period 2000 to 2010. Total factor productivity is a measure of the productivity of all inputs, or factors of production, in terms of their combined effect on output and is often accounted for by technological change or more efficient methods of producing output. TFP serves as an indicator of the performance of any production system and sustainability of the growth process. Gear wise and species wise catch -effort data and species wise average marine fish prices in different states of India obtained from Central Marine Fisheries Research Institute for the period 2000-10 were used for the analysis. The total factor productivity growth in marine fisheries sector in India was estimated using Divisia-Tornqvist indexing method. Results of the study indicated that 76 percent of the fuel requirement in the fishing industry was in the trawl sector followed by dolnetters (12 per cent), gillnetters (9 per cent) and others (3 per cent). The total diesel consumption in the year 2010 was 1,218 million litres. The average quantum of labour stood at 105 million days during 2000-10 period and nearly 70 percent of which was contributed by the mechanized sector. The input index showed a positive growth of 1.7 percent during 2000 to 2010. The output indices calculated from the quantities and revenue shares of the different resources during 2000 to 2010 period showed a growth rate of 3.4 percent. The total factor productivity showed a positive growth of 1.65 percent during 2000-10 at all India level. The state wise analysis indicated that the total factor productivity growth was positive in the east coast with a growth rate of 8.16 percent whereas in the west coast the total factor productivity growth was negative in the states of Kerala (-3.69%) and Maharashtra (-5.83%). The positive growth in total factor productivity in the east coast indicated economic sustainability of the fishing industry in the short run. Even though there was substantial increase in marine fish prices in the past decade, reduction in catches of high value fishes like crustaceans, high cost of fuel and labour led to reduced economic efficiency of fishing operations in Kerala and Maharashtra. Since marine fisheries in the country is a state subject, appropriate remedial measures are necessary for each maritime state to reduce the fishing pressure

Polyethyleneglycol-catalysed benzil-benzilic acid rearrangement: a reaction in soluble macromolecular cavities

Kinetics of benzil-benzilic acid rearrangement was investigated in the presence of polyethyleneglycols (PEG) at different concentrations. PEG of molecular weights 400 and 6000 were used for the studies. A set of solutions was prepared with varying PEG contents. The rearrangement was carried out in these systems and the rate constants were calculated. The rates surprisingly increased with PEG content instead of decreasing due to the reduced ionic movement in these viscous macromolecular solutions. In the presence of KOH and NaOH, PEG acts as a catalyst for the rearrangement. But in presence of LiOH, an inverse relation was observed between PEG content and the rate of reaction. These observations were explained on the basis of the cation-binding ability of polyethyleneglycols

Genus Perna along the coasts of India with the description of a new species Perna indica

The green and brown mussels hitherto described from the coasts of India as Mytilus have been brought under the genus Perna. The green mussel recorded and described as M. viridis by earlier workers has been renamed as P. viridis. The brown mussel exhibits characters which separate it from the green mussel (P. viridis) and hence has been subjected to a detailed study on the basis of which it has been assigned to a new species P. indic

Fishery, biology and dynamics of dogtooth tuna, Gymnosarda unicolor (Rüppell, 1838) exploited from Indian seas

Dogtooth tuna, Gymnosarda unicolor (Rüppell, 1838) (Fig. 1) is a pelagic tuna preferring waters of temperature between 21 and 26 oC. It is one of the principal species exploited by hook and line (recreational as well as commercial fishery) operated in the oceanic region. Meat of dogtooth tuna is white and so it has great demand and fetch high price (IUCN, 2011). However, occasional ciguatera fish poisoning in humans has been reported on consumption of dogtooth tuna. It is exported in fresh and frozen state and is used for the production of sashimi, canned tuna, and pouch products. Most of the world landings of dogtooth tuna during 1963 -2006 was from the Indian Ocean. Small scale tuna long lines for the species operating in the Indian Ocean belong to Taiwan, Srilanka, Maldives, Japan or Pakista