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Povzetek: In this work, the distribution of chemical elements in samples of surface water from the Strumica River Basin, North Macedonia, was studied. The water samples were collected from a total of twelve sites. In addition to the Strumica River, samples were collected from its tributaries: Bansko, Dabile, Turija, Vodoča, Radoviška, and Injevska. The determination of the concentration of 21 elements (Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, V, and Zn) was performed by inductively coupled plasma - atomic emission spectrometry (ICP-AES). All detailed information on the studied items was statistically processed using Stat Soft, 11.0 software. Using the obtained data on the concentration of the studied elements, descriptive statistical analysis of the values ​​for the concentration of the elements was performed. A map of spatial distribution was obtained for each element. The obtained results show that the concentrations of the studied elements in the surface water samples are relatively low and the distribution of most of the elements follows the lithology of the study area.
Ključne besede: rivers, surface water, heavy metals, Strumica River Basin, North Macedonia
Objavljeno v DiRROS: 20.07.2023; Ogledov: 330; Prenosov: 105
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Povzetek: European beech (Fagus sylvatica L.) is an important component of forests in the alpine and continental biogeographical regions of Croatia. This study aimed to (1) analyze the long-term response of beech to climate, (2) identify potentially critical climatic conditions that could negatively affect the radial increment (RI) and vitality of beech, and (3) evaluate differences in the response of beech between the two biogeographical regions in Croatia. We used the 16 × 16 km Croatian ICP Forests Level 1 network. On a total of 25 plots, we cored between 5 and 24 trees for dendrochronological analysis. Tree-ring widths (TRW) were measured and standardized using cubic spline. TRW chronologies for the two regions were calculated and correlated to the temperature and precipitation data and Standardized Precipitation and Evapotranspiration Index (SPEI) using bootstrapped correlations. Continental region precipitation from April to August and alpine region precipitation from June to August were significantly important for RI. Temperature was less important for RI than precipitation in both regions, but the importance of the negative impact of above-average temperatures in the continental region and the positive impact of above-average precipitation in the alpine region has increased over the last two decades. A comparison with the 3-month SPEI confirmed the significant influence of high temperatures and the lack of precipitation in August on the RI of beech trees in both regions.
Ključne besede: climate change, tree growth, forest productivity, drought, European beech
Objavljeno v DiRROS: 28.06.2023; Ogledov: 435; Prenosov: 219
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Povzetek: The high temperature corrosion at 650°C in the presence of NaCl at atmospheric pressure of AISI 304L, AISI 309, AISI 310S, AISI 314 and AISI 321 austenitic stainless steel was studied. The specimens were cyclically heated in the furnace and immersed in a 3.5% aqueous NaCl solution after cooling for 15 min. After each cycle, the change in mass of the samples was measured. The corroded samples were analysed by SEM /EDX, and the corrosion products were analysed by XRD. The chloride ions react with the steel surface to form porous and poorly adherent oxides and metal chlorides. After the mass increase during the first exposure cycles, spalling of the oxides occurred. The high temperature austenitic stainless steels (AISI 309, AISI 310S, AISI 314) showed less mass loss than conventional austenitic steels (AISI 304L). Surprisingly, the stainless steel AISI 321 showed a similar low weight loss after the cyclic test as AISI 309, but a detailed analysis of the exposed surfaces after the test showed a similar corrosion attack as for AISI 304. After the cyclic test at high temperature in the presence of NaCl, a higher concentration of Cr and Ni definitely improves the corrosion resistance under the present conditions, but a certain addition of Si is even more obvious.
Ključne besede: austenitic stainless steel, high temperature corrosion, NaCl, exhaust systems, open access
Objavljeno v DiRROS: 31.05.2023; Ogledov: 264; Prenosov: 172
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Ključne besede: electrochemical impedance spectroscopy, metal anodes, multivalent batteries, organic cathode, symmetric cell
Objavljeno v DiRROS: 17.03.2023; Ogledov: 489; Prenosov: 169
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Povzetek: Forest subsidies are widely used to achieve policy objectives aimed at maintaining and supporting the provision of the various ecosystem services provided by forests. In the European Union, an important instrument is the European Agricultural Fund for Rural Development (EAFRD) within the EU's Common Agricultural Policy (CAP), but countries also have national subsidy systems. In both cases, individual countries determine which objectives they want to achieve with the subsidy schemes and which measures are supported. In this comparative study, we investigate which forest-related measures are subsidized across Europe and which forest owners, representing a very heterogeneous group, are involved in the activities of the subsidy systems. We collected data on subsidies paid out for forest-related measures from Austria, Finland, Germany, Slovenia and Sweden from the EAFRD funding period 2014–2020 for a comparison of the funded activities. Further, we analysed how subsidies were distributed among private forest owners with forest holdings of different sizes by performing G-tests to compare the observed with the expected subsidies received by forest owners in the different size categories. The results show that through the flexibility given by the CAP for countries to adjust their subsidy programmes to the specific national needs, EAFRD funds and equivalent national subsidies are indeed used for a wide range of activities instead of only a few following one common European goal. Reflecting the different needs and various forest functions, the subsidized activities range from the more ecology-oriented “investment to increase resistance and the ecological value of forests” to the more management-oriented “purchase of new machinery and new equipment for forestry operations”. In all five countries, small-scale forest owners with holdings smaller than 200 ha are the largest owner group and manage a large share of the forest area in private hands (from 47% in Austria to 97% in Slovenia). However, especially owners of the smallest holdings (< 20 ha) rarely use the funding scheme of the EAFRD framework and thus receive a disproportionately low share of subsidies. There might be several reasons for this. Small-scale forest owners are generally less involved regarding policy issues (including subsidy schemes) than owners of larger forest holdings and may not be aware of all funding opportunities. In addition, the considerable effort to apply, including project preparation, administration and documentation may be perceived as a barrier. It became clear that the current subsidy systems of the countries focus on different forest policy objectives. Our study further revealed that the documentation of subsidy distribution is partly unclear and inconsistent across countries hampering European comparisons. However, understanding current subsidy distribution is urgently needed for increasing the effectiveness of subsidy systems to achieve European policy goals of vital multifunctional forests.
Ključne besede: European agricultural fund for rural development, EAFRD, policy, incentives, multifunctional forests, small-scale forest owners, bioeconomy
Objavljeno v DiRROS: 05.01.2023; Ogledov: 500; Prenosov: 318
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