65 research outputs found

    Every Start is Challenging: Fitting A New Artificial Lake Into the Landscape, Zalakaros, Hungary

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    The aim of this study is to conclude the experiences of the maintenance practice of an artificial thermal lake. The first years (2015-2017) of the development of the lake were analysed and evaluated along the following questions: a) What kind of design processes and maintenance interventions are related to the process of fitting the lake into the landscape? b) How have the ecological conditions of the lake evolved in the past period (zonation, succession, plantation and colonization)? c) Which general experiences could be gained from the operation of this artificial thermal lake this far? The authors of the present study were already engaged in the planning process, participating in the preparation of four different design documentations. The planting design and the maintenance instructions were based on a physico-chemical monitoring, phytoplankton, zooplankton and macroinvertebrate sampling, and machrophyte assessment. The significant processes during the three years of the lake are presented by functional groups of biota, separately assessing the characteristics of the changes of macrophytes. In 2017 an individual macroinvertebrate assessment was done, moreover a fish die-off occurred in August 2017, which are mentioned separately as well. The data in total suggested that the water of the lake is highly hypertrophic, further machrophyte introduction can prevent the plant nutriments to be absorbed by algae. Partly the algal growth but also the unlucky coincidence of other factors (e.g. high water temperature, cold weather front, maintenance problems) led to the die-off of the spontaneously overpopulated fish stock in 2017

    Impact of Low-Dose Municipal Sewage Sludge Compost Treatments on the Nutrient and the Heavy Metal Contents in a Chernozem Topsoil Near ĂšjkĂ­gyĂłs, Hungary: A 5-Year Comparison

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    Agriculture is one of the major fields, where sewage sludge can be used. Its high nutrient content can contribute to the improvement of important soil properties, such as nutrient content, water balance and soil structure. However, sewage sludge may contain hazardous components, such as pathogens and pollutants. Therefore, it is important to monitor the effects of its field application. In this paper, we assessed the impacts of two low-dose (2.5 m3/ha) municipal sewage sludge compost applications (in 2013 and in 2017) in a 5.6 ha arable land in southeast Hungary (near ĂšjkĂ­gyĂłs), located in the Hungarian Great Plain. The nutrient and the heavy metal contents in the upper soil layer (0-30 cm) of the studied Chernozem soils were compared between two sampling campaigns in 2013 (before the compost applications) and in 2018 (after the compost applications). Basic soil properties (pH, salinity, humus content, carbonate content, Arany yarn number) complemented with nutrient content (K2O, P2O5, NO2+ NO3) and heavy metal content (Cd, Co, Cr, Cu, Ni, Pb and Zn) analyses were performed. The results show that no significant change can be noticed in the baseline parameters over the 5-year period. The slight increase in the P2O5, NO2+ NO3 content is closely related to the beneficial effects of the sewage sludge deposition. The soil-bound heavy metal load did not increase significantly as a result of the compost treatments, only nickel showed a slight increase in the topsoil. In all cases the heavy metal concentrations did not reach the contamination thresholds set by Hungarian standards. The results provided positive evidences proving that low dose municipal sewage sludge compost disposal on agricultural land is safe, and can be considered as a sustainable soil amendment for agriculture in compliance with legal requirements

    Felföldy Lajos (1920–2016)

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    Felföldy Lajos (1920–2016) magyar botanika és hidrobiológia egyik legsokoldalúbb és legeredetibb egyénisége volt. Pályáját Soó Rezső irányításával kezdte, 1938 és 1946 között aktívan részt vett a debreceni és 1941–1942 között a kolozsvári Tudományegyetem Növénytani Tanszékén folyó geobotanikai kutatásokban. Számos tudományterületen maradandót alkotott. A légszennyezésnek az epifiton zuzmókra gyakorolt hatását vizsgáló kutatásai (1942) világviszonylatban is az elsők közé tartoznak. A Raunkiaer-féle növényi életforma-rendszeren belül elkülönítette a kétévesek (Hemitherophyta) életforma-típusát az egyévesekétől (1942). Úttörő szerepet játszott Magyarországon a vadon élő növényfajok citológiai (kariológiai) vizsgálatában (1947–1949). Foglalkozott növényélettannal (1951–1959), vizekben folyó primer produkcióval és algatenyésztéssel (1958–1960). 1972-ban életre hívta és 1990-ig szerkesztette a Vízügyi Hidrobiológia sorozatot. Megalapozta a magyarországi vízminőség-védelmet, amely a mai napig meghatározza a magyar hidrobiológusok szemléletét. 14 és 89 éves kora között legalább tízezer herbáriumi lapot gyűjtött. Nyugdíjba vonulása után a MTM Növénytár és az ELTE Füvészkert herbáriumi anyagának rendezésével, revíziójával foglalkozott, aktívan részt vett az Új Magyar Füvészkönyv elkészítésének munkálataiban. Munkáira egyszerre jellemző a természet iránti mély tisztelet, az elméleti megalapozottság és a gyakorlatiasság.</jats:p

    Design and Optimization of Nanostructured Lipid Carrier Containing Dexamethasone for Ophthalmic Use

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    The aim of this study was to perform a preformulation study of dexamethasone (DXM)-loaded nanostructured lipid carriers (NLCs) for ocular use. Lipid screening was applied to find the most suitable solid and liquid lipids and surfactant for the NLC formulation. The visual observation was proved with XRD measurements for the establishment of the soluble state of DXM. Thermoanalytical measurements indicated that the most relevant depression of the crystallinity index could be ensured when using a 7:3 solid lipid:oil ratio. In order to optimize the NLC composition, a 23 full factorial experimental design was used. It was established that each independent factor (lipid, DXM, and surfactant concentration) had a significant effect on the particle size while in the case of entrapment efficiency, the DXM and surfactant concentrations were significant. Lower surfactant and lipid concentrations could be beneficial because the stability and the entrapment efficacy of NLCs were more favorable. The toxicity tests on human cornea cells indicated good ophthalmic tolerability of NLCs. The in vitro drug release study predicted a higher concentration of the solute DXM on the eye surface while the Raman mapping penetration study on the porcine cornea showed a high concentration of nanocarriers in the hydrophylic stroma layer
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