6 research outputs found
Organic agriculture - Importance and development
Agriculture, as the most important strategic industry, is tasked with providing sufficient quantities of quality and safe food. Intensive and often excessive, uncontrolled, and unskilled use of the means for protection and nutrition of plants, as well as means for the prevention or treatment of animals, are carried out to increase yields in conventional production. This approach in food production has contributed to the increasingly common endangerment of the health of plants, animals and humans, as well as significant environmental endangerment. Unlike conventional production, organic food production is now increasingly attracting interest from modern consumers. However, organic agriculture involves not only producing without artificial fertilizers and other agrochemicals, but without antibiotics and hormones too. It is more of a holistic production system that functions as a sustainable unit, and unites interconnected and conditioned actors: plants, animals, microorganisms, insects, organic and mineral soil matter, and humans. In Serbia, organic agriculture has been developing for the last thirty years. However, the intensive development of organic agriculture has only happened in the last decade, with plant organic production being more developed than animal organic production
Structural, microstructural and mechanical properties of sintered iron-doped mullite
The study of an effect of iron doping on the structural, microstructural and mechanical properties of sintered iron-doped mullite is presented. The results of phase composition, performed in detail by Mossbauer spectroscopy and XRD analysis, revealed that all added iron was inside the mullite lattice forming the single phase up to 12% by weight of Fe2O3 and 1300 degrees C. Samples, which were processed at 1550 degrees C, contained secondary phases, hematite or magnetite, regardless of the amount of added iron. Furthermore, the addition of iron decreases the values of relative linear shrinkage comparing to the values of undoped one (similar to 18%) while the densities of the sintered samples rise as well as their values of microhardness. Even though the density values were not too high (90 TD%), the obtained values of microhardness were excellent, 1634 HV0.1 for maximum iron content due to the characteristic mullite microstructure
Hydrothermal synthesis of Mn2+ doped titanate nanotubes: Investigation of their structure and room temperature ferromagnetic behavior
Hydrothermal synthesis of Mn2+ doped titanate nanotubes (TNTs), which exhibited room temperature ferromagnetism (RTFM), is reported. Dispersions of 1 and 5 at.% Mn2+ doped anatase TiO2 nanocrystals were used as precursors. Size and shape of Mn2+ doped TNTs and precursor nanocrystals were studied by transmission electron microscopy (TEM). The relatively uniform size distribution of transverse dimension of nanotubes of about 10 nm was observed while their lengths varied up to few hundred nanometers. The X-Ray Diffraction (XRD) analysis and Raman spectroscopy of resultant powder confirmed the hydrogen dititanate (H2Ti2O5 x H2O) crystal phase of Mn2+ doped TNTs with the presence of small amount of sodium titanates. Electron paramagnetic resonance (EPR) experiments were performed to probe the local atomic and electronic structure of Mn in the nanotubes. Room temperature ferromagnetic ordering with saturation magnetic moment (M-s) in the range of 0.6-1.5 mu(B) per Mn atom was observed