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  • Author or Editor: A. Németh x
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Pesticide producers cannot ignore their possible obligations under the REACH regulation controlling registration, evaluation and authorization of chemicals, as only the active ingredients (and not the other composites) are exempted from REACH requirements, and more specifically only those quantities of these substances, which are used for plant protection purposes. Registration requirements show similarities with the pesticide authorization process, moreover, the required ecotoxicological tests for pesticide active substances are of the same extent as in the case of industrial substances manufactured/imported in quantities of at least 100 tons per year. A further common characteristic is the higher legal level and more centralized feature of the regulations, leading to the establishment of different authorization zones within the European Union. Although this is considered a favorable trend in case of chemical substances from the aspect of the free movement of goods, possible benefits of zonification regarding pesticides are rather questionable due to the significant differences in ecological characteristics among different areas of the European Union. Studies on genotoxic and endocrine disrupting effects are challenging the fundamentals of toxicology. Conflicting results burden the treatment of endocrine disrupters; laying down the foundations of a testing framework, and legal regulation is still ongoing. Their controversial situation is demonstrated by a few examples.

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Utilization of algae includes both macroalgae for human consumption dating back to thousands of years, as well as the application of microalgae in health promoting dietary supplements. The autotrophic growth of microalgae is slow, but can be accelerated by optimizing their cultivation conditions. Efficiency optimizations for time and economy should be performed in many parallel experiments. A new high-throughput microalgae cultivation method is presented here, applying 24-low-well microplate with varying illumination, in which the cell growth is followed via evaluation of scanned images. A strain of the genus Nannochloropsis and two Chlorella vulgaris species have been chosen as well described and frequently applied model organisms in order to test the recently developed cultivation system. In these scaled down experiments, the custom design lighting panel was tested by studying the effect of the colour of illumination on cell growth kinetics. RGB LEDs (i.e. light emitting diodes, red: 622 nm, green: 528 nm, and blue: 467 nm) were used individually or together providing red, green, blue, and white colours. While the effect of light’s colour on algae growth was evaluated, also the new system was proven to be suitable for comparing maximal growth rates for different microalgae strains. While the tested two Chlorella isolates reached 1.2–1.4 g l–1 concentrations, the Nannochloropsis strain reached 1.4 g l–1 final cell dry weight, and specific growth rates were observed between 0.58–0.62 day–1.

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In existing processes, the extraction of steviol glycosides from stevia leaves involves many process steps often including extraction by organic solvents. The purpose of the present study was to develop a process for the effective extraction of steviol glycosides, which can provide a concentrated juice exhibiting a high level of recovery with regard to the target compounds, rebaudioside A and stevioside. Pressurized Hot Water Extraction (PHWE) was first optimized with Response Surface Methodology in terms of maximized rebaudioside-A yield and minimized colour components. PHWE was then combined with pressing in a wine-press, resulting higher efficiency for extracting both steviol glycosides in comparison to the reported methods in the literature. Finally, spray drying was applied for both product stabilization and removal of contaminants.

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Bedrock has an essential role in the formation of soils, it fundamentally determines mineral composition. The present research focuses on the minerals in forest soils formed in the Bükk Mountains (NE Hungary). The composition of soil minerals was in accordance with the geological features as well as with the changes in climate and vegetation, which provide a basis for tracking the past of the soil formation mechanisms (Nemecz, 2006). Thus, by studying the mineral composition the formation processes and development of the soils can be unveiled.According to the findings it can be assumed that the investigated soils, although formed primarily on solid limestone, cannot be the products of the weathering of limestone solely, as they also contain significant amounts of silicates. The major part of the soil forming materials presumably originates from earlier dust fallings or from alluvial deposits by erosion. The former assumption is confirmed by the fact that the investigated area is located at a high altitude, thus significant amounts of eroded material could only originate from a short distance, where the bedrock also consists of limestone. Further research is needed for more detailed knowledge on the mineral composition of the soils, thus on the development of the soils and the bedrock of the investigated area.

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The present article discusses the applicability of thermoanalytical methods in the analysis of Hungarian soils formed on carbonate rocks. Up to now only limited mineralogical and soil chemical research has been done on these soils. Soils from the Bükk Mountains, the most varied limestone region in Hungary, were used for the investigations. The aim was to extend our incomplete knowledge on the mineral composition and formation processes of these soils and to demonstrate the possibilities and evaluation potential of thermoanalytical techniques. All the soils investigated were formed on limestone and had different surface soil thickness, influenced by the accumulation of silicate debris and the microterrain. The results of soil mineralogical analysis revealed an extraordinarily high proportion of quartz compared to that of other minerals (especially calcite), indicating that these soils could not have originated solely from the weathering of the limestone bedrock. The results also showed that thermoanalytical methods could complement classical chemical and instrumental (XRPD) methods in research on the genesis of soils formed on limestone.

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This paper introduces the alternating conditional expectation (ACE) algorithm of Breiman and Friedman (1985) in multiple regression problems in groundwater monitoring data analysis. This special inverse nonparametric approach can be applied easily for estimating the optimal transformations of different groundwater monitoring data from the Bükk Mountains to obtain maximum correlation between observed aquifer variables. The approach does not require a priori assumptions of a mathematical form, and the optimal transformations are derived solely based on the groundwater data set. The advantages and applicability of the proposed approach to solve different multiple regression problems in hydrogeology or in groundwater management are illustrated by means of case studies from a Hungarian karst aquifer. It is demonstrated that the ACE method has certain advantages in some fitting problems of groundwater science over the traditional multiple regression.In the past, different groundwater monitoring data (like groundwater level, groundwater temperature and conductance, etc.) had been used for groundwater management purposes in the Bükk Mountains. One of the difficulties in earlier approaches has been the need to make some kind of assumption of the expected mathematical forms among the investigated reservoir and petrophysical variables. By using nonparametric regression, the need to assume a specific form of model is avoided, and a clearer vision of the relationships between aquifer parameters can be revealed in the Bükk Mountains, where karst water is the main source of potable water supply. Complex monitoring data from the Bükk Mountains were analyzed using the ACE inverse method, and results were verified successfully against quantitative and qualitative field observations.

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Abstract  

A new approach for the study of ion transport by an in situ radiotracer method is presented. The method is based upon the measurement of the intensity and energy spectrum change of -radiation during the penetration of labeled species. The applicability of the radiotracer technique is detailed through the measurement of the transport of labeled chloride ions into a PERMAPLEX-A20 anion exchanger membrane. The proposed method is applicable to in situ monitoring of the motion of ions in the membrane (or adsorbent).

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Authors: E. Durszt, J. Németh and A. Varga

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Authors: R. Szőllősi, A. Medvegy, E. Benyes, A. Németh and E. Mihalik

Numerous experiments have suggested that in many species higher floral display can be more attractive for pollinators, but the possibility of between-flower self-pollination, namely geitonogamy may reduce the floral longevity, the fitness of both individuals and the offspring. In this study we investigated how phenological parameters (mainly floral display) change temporally and how they affect the female reproductive success of cymose Iris sibirica. We found that in blooming sequence of both individuals and the population 3 sections can be separated. The number of levels and flowers per stalks on the plants observed was very variable yearly. Female reproductive success parameters (fruit set and seed set) showed intra- and interannual variations, which were probably due to intra-plant resource allocation.

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Authors: Cs. Németh, J. Somlai, Á. Nényei, M. Skrinyár, B. Kanyár, P. Németh and K. Hoffer

Abstract  

Slags, derived from coal mined in the neighbourhood of the town Tatabánya in Hungary, have been used as filling and insulating material for buildings of houses, block of flats, schools and kindergartens. The slag samples come from here have elevated concentrations of 226Ra, (range of 850–2400 Bq·kg–1). Therefore, the external gamma dose rates at 1 m height were about four times higher than the world average. It has been found, based on the modelling, that the dose rate could be decreased with 70–80% using an appropriate thickness of concrete or barite-concrete layers.

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