11 research outputs found

    Vulnerability to natural disasters in Serbia: spatial and temporal comparison

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    The frequency of natural disasters and the extent of their consequences at a global level are constantly increasing. This trend is partially caused by increased population vulnerability, which implies the degree of population vulnerability due to high magnitude natural processes. This paper presents an analysis of vulnerability to natural disaster in Serbia in the second half of the twentieth and the early twenty-first century. Vulnerability changes were traced on the basis of demographicā€“economic indicators derived from statistical data for local government units (municipalities) provided by the Statistical Office of the Republic of Serbia. Calculations were performed in the geographical information system environment. The results of the study show that spatial and temporal vulnerability variations are causally correlated with changes in the selected components. Significant rise of vulnerability is related to urban areas, while lower values are characteristic for other areas of Serbia; this is primarily a consequence of different population density

    Fine nanophased ZnO : Ru and ZnO : Pt powder synthesis through aerosols

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    Pt/Ru-doped ZnO nanophase particles were synthesized using ultrasonic spray pyrolysis. Particles were obtained through decomposition of zinc nitrate and newly developed Pt(IV) and Ru(III) complexes. The particle morphology, phase composition and chemical structure were revealed in accordance to various analysis methods (XRD, DSC, SEWEDS, TEM) and discussed in terms of precursor chemistry and process parameters. The shape of DSC curves, indicating two exothermic effects above 600 degrees C in both ZnO:Ru and ZnO:Pt, gave an indication of irreversible structural changes and high reactivity of as-prepared powders. The hexagonal wurtzite-type ZnO phase was revealed in both powdered samples. Small content of an intermediate Zn-5(NO3)(2)(OH)(8)(.)2H(2)O and cubic Zn2PtO4 phase were detected in the Pt-doped ZnO particles. Structural refinements, performed by Koalariet-XFit, suggest the composite internal particle structure composed of primary particles sized less than 100 nm. The estimated values for the unit cell parameters and Zn-O bond lengths imply noble metal ions incorporation into ZnO matrix interstitially, probably in octahedral interstitial environment. It has been shown that different particle growing morphologies (either spheroidally or pyramidally shaped) were influenced by the precursor chemistry, processing parameters and the presence of noble metal ions. Among the many parameters, attaining of the particle shape uniformity and homogeneous distribution of the noble metal cations in as-prepared particles are regarded as the most important factors for dominating microstructure evolution

    Aerosol synthesis of pure and Pt-doped ZnO particles using nitrate and pdda-Pt(IV) complex solutions

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    Pure and Pt-doped ZnO nanophase particles were synthesized by ultrasonic spray pyrolysis. The particles were obtained through the decomposition of zinc nitrate and with a newly developed Pt(IV) complex with 1,3 -propylenediamine-NN'-diacetate tetradentate class ligand (pdda). The complex was characterized by elemental analysis, electronic absorption and infrared spectroscopy. The form of the determined complex structure {trans-[Pt(pdda)Br-2]center dot H2O} implies that Pt(IV) ion has a distorted octahedral coordination due to intramolecular N-H center dot center dot center dot Br interaction. The results of structural refinement (cell parameters, bond lengths, and ion occupancy) of ultrasonically derived pure and Pt-doped ZnO particles suggest either the formation of Zn-i interstitials or platinum ion incorporation into the ZnO lattice in octahedral interstitial positions, respectively. A well-crystallized hexagonal wurtzite structure of ZnO was pronounced in all investigated samples [JCPDS card 36-1415, Joint Committee on Powder Diffraction Standards, defined by International Centre for Diffraction Data (www.icdd.com)]. Phase determination also indicated the presence of a nitrate hydroxide hydrate phase (JCPDS card 24-1460), as a result of incomplete precursor decomposition and a spinel Zn2PtO4 phase (below 1.0 wt%) located in the boundary region for a Pt-doped ZnO sample. Based on x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy analyses, it was shown that the different particle growing morphologies, which were either spheroidally or pyramidally shaped, were influenced by the precursor chemistry, processing parameters and the presence of platinum ions. The composite internal particle structure revealed by transmission electron microscopy and selected area electron diffraction analyses, implied that the secondary particles represent an assembly of primary particles sized under 60 nm aroused during the processes of nucleation, growth and aggregation. Both hexagonal and spheroidal shape of primary particles was evident. The particle morphology, primarily particle size and the mechanism of Pt4+ ion introduction into the ZnO cell was discussed based on the structural refinement and selected area electron diffraction analysis

    What identities in the present may mean for the future of the Western Balkans

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    The post-conflict generation experiences ethno-religious identity as being thrust upon them, regardless of how much they care about belonging to such groups. Language and physical barriers segregate groups; in addition, one ethnic group in each nation is promoted above others in constitutions and political rhetoric. Because religious groups and ethnicities overlap almost perfectly, identifying with one is the same as identifying with the other, and that leaves little opportunity to develop complex identities that can overlap with those of different others. Yet young adults do not want inequality to be made of the meaning of their social identity and minor changes in social practices could help build nations as communities
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