Appearance and disappearance of superconductivity in SmFe1-xNixAsO (x = 0.0 to 1.0)

Bulk polycrystalline Ni-substituted SmFe1-xNixAsO (x = 0.0 to 1.0) samples are synthesized by solid state reaction route in an evacuated sealed quartz tube. The cell volume decreases with increase of Ni content in SmFe1-xNixAsO, thus indicating successful substitution of smaller ion Ni at Fe site. The resistivity measurements showed that the spin-density-wave (SDW) transition is suppressed drastically with Ni doping and subsequently superconductivity is achieved in a narrow range of x from 0.04 to 0.10 with maximum Tc of 9K at x = 0.06. For higher content of Ni (x > 0.10), the system becomes metallic and superconductivity is not observed down to 2K. The magneto-transport [R(T)H] measurements exhibited the upper critical field [Hc2(0)] of up to 300kOe. The flux flow activation energy (U/kB) is estimated ~98.37K for 0.1T field. Magnetic susceptibility measurements also confirms bulk superconductivity for x = 0.04, 0.06 and 0.08 samples. The lower critical field (Hc1) is around 100Oe at 2K for x = 0.06 sample. Heat capacity CP(T) measurements exhibited a hump like transition pertaining to SDW in Fe planes at around 150K and an AFM ordering of Sm spins below temperature of 5.4K for ordered Sm spins [TN(Sm)]. Though, the SDW hump for Fe spins disappears for Ni doped samples, the TN (Sm) remains unaltered but with a reduced transition height, i.e., decreased entropy. In conclusion, complete phase diagram of SmFe1-xNixAsO (x = 0.0 to 1.0) is studied in terms of its structural, electrical, magnetic and thermal properties.Comment: 18 pages text + Figures; comments suggestions welcome ([email protected]

Utilization of Marine Fishery Wastes for Protease Production by Halophilic Bacterium Halolactibacillus Miurensis RSK CAS7- A Microbial Approach

The marine wastes generates 50–60% of the total weight of shell fish as waste consists of protein (35–50%), chitin (15–25% of dry weight) which considered as major environmental pollutants due to uncontrolled dumping. The utilisation of marine waste not only solves environmental problems but also decreases the production costs of microbial products. So far in this study, halophilic bacterium was isolated from marine ascidians and identified as Halolactibacillus miurensis RSK CAS7 through 16S rRNA sequence. The effect of different marine wastes such as shrimp shell powder (SSP), crab shell powder (CSP), squid pen powder (SPP), sardinella powder, tuna powder and anchovy powder were tested on protease production. Among these Sardinella powder (579.46 U/ml) and shrimp shell powder (470.36 U/ml) showed maximum level of protease production and followed by other marine wastes. All the significant nutrients identified from the preliminary screening were further screened by using Plackett - Burman Design and it resulted sardinella powder, K2HPO4,NaCl and pH were the highly influencing factors and their concentration were further optimized by using central composite design. Central composite design revealed that four independent variables such as Sardinella powder (14.21 g/l), K2HPO4 (3.81 g/l), NaCl (154.1 g/l) and pH (9.0) were significantly influenced the protease production. With these optimum concentration levels, the maximum protease production (1,794.41 U/ml) was observed. Thus, protease production by microbial conversion of marine wastes suggested its potential utilisation for the production of high value products.Keywords: Waste Management, Protease, Marine Wastes, Halophilic Bacteri

Leprosy post-exposure prophylaxis with single-dose rifampicin

_Objective:_ Leprosy post-exposure prophylaxis with single-dose rifampicin (SDRPEP) has proven effective and feasible, and is recommended by WHO since 2018. This SDR-PEP toolkit was developed through the experience of the leprosy postexposure prophylaxis (LPEP) programme. It has been designed to facilitate and standardise the implementation of contact tracing and SDR-PEP administration in regions and countries that start the intervention. _Results:_ Four tools were developed, incorporating the current evidence for SDRPEP and the methods and learnings from the LPEP project in eight countries. (1) th

Superstripes and complexity in high-temperature superconductors

While for many years the lattice, electronic and magnetic complexity of high-temperature superconductors (HTS) has been considered responsible for hindering the search of the mechanism of HTS now the complexity of HTS is proposed to be essential for the quantum mechanism raising the superconducting critical temperature. The complexity is shown by the lattice heterogeneous architecture: a) heterostructures at atomic limit; b) electronic heterogeneity: multiple components in the normal phase; c) superconducting heterogeneity: multiple superconducting gaps in different points of the real space and of the momentum space. The complex phase separation forms an unconventional granular superconductor in a landscape of nanoscale superconducting striped droplets which is called the "superstripes" scenario. The interplay and competition between magnetic orbital charge and lattice fluctuations seems to be essential for the quantum mechanism that suppresses thermal decoherence effects at an optimum inhomogeneity.Comment: 20 pages, 3 figures; J. Supercon. Nov. Mag. 201