Conflicts of interest in the use of Antarctica

The International Geophysical Year of 1957–58 demonstrated the effective use of the Antarctic for peaceful international scientific activity, and the Antarctic Treaty of 1961 acknowledges the important contribution of science. The pre-eminent position accorded to science has been vindicated: 30 years of intensive research have shown the intimate connections and controlling influences of Antarctica on the principal environmental systems of planet Earth (climate, ocean circulation and sea level

Allometry of heavy metal bioconcentration in the echinoid Paracentrotus lividus

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Improved piezoelectric and energy harvesting characteristics in lead-free Fe2O3 modified KNN ceramics

Lead-free piezoelectric ceramics gained an increased attention due to their high piezoelectric properties combined with the absence of lead and other potentially hazardous elements. In this work, we used a unimorph cantilever beam arrangement to study piezoelectric energy harvesting in pristine K0.5Na0.5NbO3 (KNN) and Fe2O3 modified KNN (KNFN) ceramics that are potential candidates for PZT replacement. The piezoelectric ceramics were synthesized using conventional solid state reaction method. The KNFN ceramics exhibited a superior piezoelectric performance: d (33) = 100 pC/N and mechanical quality factor (Q (m) = 135) as compared to KNN (d (33) = 83 pC/N; Q (m) = 76). In addition, the planar electromechanical coupling factor k (p) was higher in case of KNFN having a value of 0.39 as compared to 0.34 for KNN. The KNFN harvester generated an output power of 0.38 mW/cm(3) at a load resistance of 470 k Omega for a transverse displacement amplitude of 1.2 mm. The prospects of using lead-free ceramics for piezoelectric energy harvesting are discussed