Mercury pollution of sediments from the river Tisa (Serbia)

Mercury (Hg) has been listed as a global high priority pollutant by many international organizations due to its mobility and persistence in the environments and high toxicity to organisms. This research was conducted with the aims to determine: (i) total Hg content (THg) and its spatial distribution in sediments of river Tisa along the river course, (ii) possible sources of THg and (iii) degree of THg pollution in sediments from the river Tisa through different criteria. Total Hg in the sediments ranged from 0.07 to 0.49 mg kg-1, with mean ± S.D. value of 0.26 ± 0.10 mg kg-1. The highest mean value of THg (0.30 mg kg-1) was found in the lower stream, while the lowest (0.13 mg kg-1) was found in the tributary. According to Principal Component Analyses (PCA) strong positive loading of metals in all parts of the river Tisa is mainly controlled from the same sources. These sources are related to anthropogenic activities based on calculated Enrichment Factor (EF) values. Total Hg are higher than background value. According to the Republic of Serbia official standard, THg values of river Tisa sediments were within the range of maximum permissible values. Compared with National Oceanic and Atmospheric Administration (NOAA) guideline, 80.49% of sediment samples indicated that THg in the river Tisa sediments represented minimal and possible risk towards the living organisms. Integrating the results of pollution assessment, it could be concluded that THg in river Tisa sediments in Serbia demonstrates considerable contamination according to Geoaccumulation Index (Igeo), and Contaminant Factor (CF), and high pollution risk according to Potential Environmental Risk Index (PERI)

Implementation of climate change science in viticulture sustainable development planning in Serbia

Growing interest in Serbia in adaptation of viticulture to climate change emerged from a recorded positive impact of summer increased draught on domestic wine quality. Another motivation is that viticulture has been recognized as one of the fastest developing agricultural sectors in Serbia and, to contain its growing potential, it is crucial to provide basis for its future sustainable development. Prioritization and implementation of adaptation measures in practice require reliable assessment of climate projections. For climate change impact assessment is used high resolution multi-model ensemble of nine regional climate models simulations, bias corrected, with two most probable future scenarios of GHG emissions RCP4.5 and RCP8.5, for the period 2016-2100. Analysis has been done for the near future, mid-century and end of the century periods. The periods are defined according to the IPCC 5th Assessment Report, which enables comparison of climate change impacts with a wider region, and preferably motivate future international collaboration and knowledge exchange

Effect of plant arrangement pattern and irrigation on efficiency of maize (Zea mays) and bean (Phaseolus vulgaris) intercropping system

A field study was conducted on an experimental held of the Maize Research Institute Zemun Polje-Belgrade (latitude: 44 degrees 49' N), Yugoslavia over a 3 year period (1994-1996). The objective of this study was to find the optimal spatial arrangement of a maize-beans intercrop in irrigated and rainfed farming systems. Plant arrangement patterns in an intercropping system did not significantly affect LAI values in maize compared with a sole crop, while irrigation had a greater positive influence on it. Leaf area values of beans were Inore sensitive to the same treatments. Microenvironmental conditions in maize-bean mixtures were Inore favourable for bean crop than for sole brans. An intercropping system had a greater influence on yield components of maize. Component combination 1/2:1/2 (maize:bean) was most effective in all yield components of maize. Intraspecific competition appears to be more intense than interspecific competition in both crops. Yield component of bean was more sensitive to water regime of the site than to planting pattern in an intercrop. Irrigation increased all yield components of bean (especially pod number). The intercropping system decreased harvest index in both crops compared with monocrops. Maximum total grain yield was in 1994 in irrigated maize-bean intercrop 1/2:1/2, with highest efficiency being in an intercrop in irrigation in 1995. The Land Equivalent Ratio (LER), based on grain yield, was consistently greater than 1.0 in an irrigation water regime in 1995. Proportion of maize:bean = 1/2:1/2 gave the highest increase of yield (LER = 1.54). Under conditions of chernozem soil type in Zemun Polje, with often-expressed dry periods, irrigation is a very important measure for increasing maize-beans intercrop productivity

Economical driving in the function of increasing the efficency of road transport companies

The main goal of road transport companies, whose activity is transport of goods or passengers, is to constantly increase the efficiency of the resources at their disposal in order to increase the transport market competitiveness. As fuel costs compose one of the largest costs in overall business, their reduction has a significant impact on the final product price. The paper presents the eco - driving significance, that can be used as a toll for increasing the transport fleet efficiency. The driver’s eco - driving training was carried out at the Public transport company in Belgrade by instructors of RICo training centre (Accredited training institute). Analysing the driving parameters before and after training, there were achieved the savings from 9,1% to 20,41% in total fuel consumption, average fuel consumption and average CO2 emissions after training

Thermal stability and degradation of binuclear hexaaqua-bis(ethylenediamine)-(μ 2-pyromellitato)dinickel(II) tetrahydrate

Thermal degradation of ternary transition metal complex containing tetraanion of pyromellitic acid, pyr, and ethylenediamine, en, [Ni2(en)2(H2O)6(pyr)]·4H2O, 1, was investigated under non-isothermal conditions. The mechanism of thermal degradation, which occurs in three steps, was clarified by TG/DSC measurements in conjunction with FT-IR spectroscopy and XRPD analysis. The complexity of all degradation steps has been revealed using isoconversional methods. Dehydration comprises the loss of ten water molecules in a relatively narrow temperature interval, resulting in a very complicated reaction mechanism. In addition, density functional theory calculations have been applied for better understanding of dehydration. The second degradation step, related to loss of en, was separated into two single-step processes with Fraser–Suzuki function. The obtained individual steps were described by Johnson–Mehl–Avrami A2 model and Šesták–Berggren model, respectively. Validation of the proposed kinetic triplets for individual steps was performed using master plot and Pérez-Maqueda criteria. The third degradation step is related to the fragmentation of pyr ion most likely followed with the release of a number of gaseous products

The Middle Cenomanian basal series of Planinica, Western Serbia

Sedimentary rocks of the Upper Cretaceous basal series found at the village of Planinica, Western Serbia, are composed of thick coarse clastics and beds and intercalations of medium- to fine-grained clastics. The series lies transgressively over Jurassic serpentinite and peridotite, and under Upper Miocene marlstone and marly limestone. Sedimentary, petrographic, paleontological, and biostratigraphic characteristics of the basal series are described and its lithological members and their structural features are identified. From medium-grained sandy matrix in thick coarse clastics, two ammonite taxa, four brachiopod taxa (including the new taxa Orbirhynchia oweni and "Terebratula" n. gen. et sp.), and eleven echinoid taxa are described. The brachiopod species Kingena concinna Owen is used in dating the basal series as Middle Cenomanian, whereas limestone fragments in coarse clastics correspond to the Late Albian and Early Cenomanian

Influence of laser-induced heating on MnO nanoparticles

The phase changes of MnO nanoparticles under laser-induced heating have been studied. Previous confirmation of the existence of MnO phase was based on the X-ray diffraction measurements. Here, we report the experimental spectra of nonresonant Raman scattering in the range between 100 and 1,600cm(-1), for a sample irradiated with 8 different laser powers. The laser-induced heating has produced change in existing phases in sample, destruction of MnO phase, and creation of MnO2, Mn3O4, and MnOOH phases along with formation of Mn2+ on the sample surface. These phase changes have been confirmed by X-ray diffraction and atomic force microscopy measurements

Surface optical phonon – Plasmon interaction in nanodimensional CdTe thin films

Structural and optical properties of CdTe thin films were investigated applying atomic force microscopy (AFM), XRD powder technique, Raman spectroscopy and far–infrared spectroscopy. CdTe thin films were prepared by using thermal evaporation technique. In the analysis of the far – infrared reflection spectra, numerical model for calculating the reflectivity coefficient for system which includes films and substrate has been applied. Effective permittivity of film mixture (CdTe and air) was modeled by Maxwell – Garnet approximation. We reveal the existence of surface optical phonon (SOP) mode and coupled plasmon-SOP modes (CPSOPM). © 2018 Elsevier B.V

Synthesis and thermal stability of cis-dichloro[(E)-ethyl-2-(2-((8-hydroxyquinolin-2-il)methylene)hidrazinyl)acetate-kappa(2) N]-palladium(II) complex

The structure of new cis-dichloro[(E)-ethyl-2-(2-((8-hydroxyquinolin-2-il)methylene)hidrazinyl)acetate-kappa(2) N]-palladium(II) complex was determined using a combination of XRD and IR measurements and DFT calculations. Inherent flexibility of its structure is evident from the complexity of its IR spectrum, which could only be theoretically reproduced as a combination of several closely related structures, involving rotation around C-O bond and changes in hydrogen interactions of its -OH group. Its thermal stability and decomposition were studied non-isothermally, and the thermal decomposition mechanism was proposed using correlation with DFT calculations at the molecular level. It was determined that the initial degradation step consists of the release of Cl free radical, which then reacts with both the initial compound and the degradation products. Besides the endothermic steps, there are exothermic ones, contributing to the complex shape of the DSC curve, consisted of overlapping endothermic and exothermic peaks. Deconvolution of DTG curve allowed identification of primary fragments of the initial degradation process and, in conjunction with DFT calculations, construction of the most likely reaction mechanism