Dynamic Ratio Correlation of N:P in relation to the Diatom Abundance in the Intensive System of the Vannamei (Litopenaeus vannamei) Shrimp Pond

Diatoms are one type of aquatic phytoplankton that has an important role. Diatoms, or Bacillariophycyae, are a phytoplankton that suits the needs of the shrimp cultivation in the pond because diatoms are an abundant primary producer and are needed as natural feed. Diatom needs nitrogen and phosphate in its life, while the nutrient itself in the water is not always in a stable condition. The research aimed to determine the dynamic ratio correlation of N:P in relation to the diatom abundance in intensive system vannamei (Litopenaeus vannamei) shrimp ponds in order to maintain aquatic stability or living media within intensive system vannamei shrimp cultivation. The main parameters observed were Ammonium, Nitric, Nitrate and Phosphate, as well as the abundance of diatom plankton. The supporting parameters measured were pH and clarity in the intensive vannamei shrimp pond in Banyuwangi. Based on results of the data analysis and the study about correlation of dynamic ration N:P toward abundance of Diatom, it can be concluded that the ratio value of N:P influences the composition of the level classification of the phytoplankton in aquatic cultivation. The differences in the level of ammonium, nitric, nitrate and phosphate provide different influences on the diatom abundance in the water. A high level of nitrate indicates an abundance of diatoms

MoRe/YBCO Josephson junctions and π -loops

We have developed Josephson junctions between the d-wave superconductor YBa2Cu3O7−x (YBCO) and the s-wave Mo0.6Re0.4 (MoRe) alloy superconductor (ds-JJs). Such ds Josephson junctions are of interest for superconducting electronics making use of incorporated π-phase shifts. The I(V)-characteristics of the ds-JJs demonstrate a twice larger critical current along the [100] axis of the YBCO film compared to similarly-oriented ds-JJs made with a Nb top electrode. The characteristic voltage I c R n of the YBCO–Au–MoRe ds-JJs is 750 μV at 4.2 K. The ds-JJs that are oriented along the [100] or [010] axes of the YBCO film exhibit a 200 times higher critical current than similar ds-JJs oriented along the [110] axis of the same YBCO film. A critical current density J c = 20 kA cm−2 at 4.2 K was achieved. Different layouts of π-loops based on the novel ds-JJs were arranged in various mutual coupling configurations. Spontaneous persistent currents in the π-loops were investigated using scanning SQUID microscopy. Magnetic states of the π-loops were manipulated by currents in integrated bias lines. Higher flux states up to ±2.5Φ0 were induced and stabilized in the π-loops. Crossover temperatures between thermally activated and quantum tunneling switching processes in the ds-JJs were estimated. The demonstrated ability to stabilise and manipulate states of π-loops paves the way towards new computing concepts such as quantum annealing computing