Harvesting Power Through Random Vibrations of Aerospace Vehicles from Nanostructured La-Pb(Ni1/3Sb2/3) - PbZrTiO3 Ferroelectric Ceramics

Synthesis by mechanochemical activation route and optimisation for power harvesting properties of nano-structured Pb0.98La0.02(NiSb)0.05[(Zr0.52Ti0.48)0.995]0.95O3 [La-PNS-PZT] ferroelectric ceramic composition has been carried out and reported here for the first time. Progressive perovskite phase formation during mechanical activation from 5 h to 40 h followed by reactive sintering was analyzed from X-Ray Diffraction analysis. Noticeable formation of perovskite phase after10 h of milling and further its completion in successive reactive sintering was observed. Particle morphology of the 10 h activated nano-La-PNS-PZT powder analysed by High Resolution Transmission Electron Microscope (HRTEM) indicated average particle size (d50) of about 24nm. Microstructural studies of samples reactively sintered at 1220 °C were performed by Field Emission Scanning Electron Microscopy (FESEM) for powders activated for various durations, indicated the compact microstructure for 10 h activation which resulted in optimum piezoelectric properties viz. piezoelectric charge coefficient (d33=449x10-12 C/N), piezoelectric voltage coefficient (g33= 32x10-3 m-V/N), Figure of merit for power harvesting (14.4 x10-12 V-m-C/N2) accompanied by excellent stability of permittivity in the range -50 °C to 100 °C. The output voltage obtained from simulated random vibrations of aerospace vehicles at various Power Spectrum Density (PSD) values, measures about 3.0 mV output across resistance of 1 kΩ  indicating suitability of composition for harvesting the power from aerospace vehicle vibrations

Cholecystocutaneous Fistula Secondary to Chronic Calculous Cholecystitis

Spontaneous cholecystocutaneous fistula is an exceptionally unusual complication of chronic calculous cholecystitis now. The remarkable drop in incidence is probably associated with the introduction of antimicrobial therapy and early surgical management of biliary tract disease. We report a case of spontaneous cholecystocutaneous fistula in a patient who presented with an abscess in the right upper quadrant

The nil Hecke ring and singularity of Schubert varieties

We give a criterion for smoothness of a point in any Schubert variety in any G/B in terms of the nil Hecke ring.Comment: AMSTE

Rapidity distribution as a probe for elliptical flow at intermediate energies

Interplay between the spectator and participant matter in heavy-ion collisions is investigated within isospin dependent quantum molecular dynamics (IQMD) model in term of rapidity distribution of light charged particles. The effect of different types and size rapidity distributions is studied in elliptical flow. The elliptical flow patterns show important role of the nearby spectator matter on the participant zone. This role is further explained on the basis of passing time of the spectator and expansion time of the participant zone. The transition from the in-plane to out-of-plane is observed only when the mid-rapidity region is included in the rapidity bin, otherwise no transition occurs. The transition energy is found to be highly sensitive towards the size of the rapidity bin, while weakly on the type of the rapidity distribution. The theoretical results are also compared with the experimental findings and are found in good agreement.Comment: 8 figure

B_s --> mu+ mu- decay in the R-parity violating minimal supergravity

We study B_s --> mu+ mu- in the context of the R-parity violating minimal supergravity in the high tan beta regime. We find that the lowest value of the branching ratio can go well below the present LHCb sensitivity and hence B_s --> mu+ mu- can even be invisible to the LHC. We also find that the present upper bound on Br(B_s --> mu+ mu-) puts strong constraint on the minimal supergravity parameter space. The constraints become more severe if the upper bound is close to its standard model prediction.Comment: 18 pages, 10 figures; version to be published in European Physical Journal