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  • Author or Editor: A. Kiss x
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Abstract  

The aim of the present work was to provide arguments to the almost ‘hystorical’ problem of what β-tungsten is. WO3was reduced in dry H2gas atmosphere in order to examine, whether β-tungsten formed in such a way contains oxygen as part of the lattice described as WxO (e.g. W20O) or is a pure metallic phase of tungsten. As a result of thermoanalytical measurements and of chemical analysis for oxygen, the assumption is supported that in the 600-800C temperature range of metal formation not the WxO (β-W)→W(α-W) transformation but the β-W→α-W structural rearrangement of materials with identical chemical composition is the most probable process. The earlier opinion that the formation of the β-W structure requires the presence of oxygen atoms was not verified by our results.

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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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Authors: K. T. Kiss and A Földi
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The magnesium, calcium and aluminium contents in different soybean seeds depended on both the variety and the soil type. Late-ripening soybean varieties were compared with early and intermediate varieties. The element contents of the early varieties were lower than those of the intermediate and late soybean varieties grown at the same experimental site. In addition to measurements on whole soybean seeds, the seed-coat and inner parts were also analysed separately. The magnesium, calcium and aluminium contents of the seed-coat were higher than those of the inner parts. There were only slight differences in the contents of protein and crude fat, and no correlation was found with the magnesium contents. The correlation between the magnesium coefficient (z) and the protein content (Kiss, 1974) was valid only in cases where the difference between the magnesium coefficients of two plants was more than 0.1.

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The biologically active amines of grapes, aszú-grapes, aszú-wines of Tokaj region were analysed to study the effect of Botrytis cinerea on the grapes. It was established that grapes contained mainly spermidine, putrescine and spermine, however, in the aszú-grapes new amine compounds such as agmatine, phenethylamine, butylamine and pentylamine isomers appeared. The spermine content showed an increase in all aszú-grape varieties compared to the grapes. During winemaking processes, spermine disappeared and the concentration of tyramine increased in the aszú-wines. The concentration of spermidine decreased during the ageing of the product. The ratio of tyramine and amine content of the samples were found to be within a limited interval.

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Epipactis albensis Nováková et Rydlo (Orchidaceae), a species previously undocumented in the flora of Ukraine, was found in three localities in this country (in vicinity of Chetfalva, Fanchykovo and Drotyntsi, Zakarpattia district) in 2012. The species (originally described from the Czech Republic) recently has only been known to exist in seven Central European countries. The three Ukrainian populations described here stretch within the floodplain of river Tisza. Based on measurements in 14 localities in Hungary, Ukraine and Romania the species has a considerably wide soil reaction tolerance (from 3.6 to 7.2 pHKCl). The fruit set of this strictly autogamous species is reasonably high (78%). The mean±SD thousand seed weight of the species was 0.0030±0.0005 grams, therefore E. albenis is classified into the hypermeichor seed-weight class. Recent discoveries of the species in Romania and Ukraine raise the possibility of its occurrence in further European countries.

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Abstract  

Investigations of the possible use of Mössbauer measurements for the analysis of the corrosion products of iron are reported. The Mössbauer spectrum was measured at room and liquid nitrogen temperatures on two samples produced by different corrosion procedures. The isomeric shift, quadrupole splitting and magnetic splitting observed in the spectra yield information on the chemical composition. In this way, the chemical forms of the compounds in the samples could be established. The magnetic properties, revealed by the spectra taken at different temperatures, permitted the identification of the polymorphous modifications. The rust produced in air saturated with water vapour was found to consist of 50% (w/w) Fe2O3,∼40% γ-FeOOH, and ∼10% β-FeOOH, while the rust produced by periodical immersion in saturated calcium chloride solution is composed of about equal amounts of β-FeOOH and γ-FeOOH. These findings have been confirmed by the thermoanalytical curves of the samples. The Mössbauer effect presents a convenient method for the investigation of the corrosion products of iron.

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Authors: Gy. Kiss, A. Malnič and D. Marušič
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Sustainable nutrition (SN) considers the environmental impact of food production. This study aims to analyse the relationship between nutrient density and water footprint (WF) of the most consumed food items in Hungary and to create a classification of nutrients. Based on a comprehensive analysis of literature and different data sources, the authors analysed the stochastic relationship between WF and nutrient density of different food items by Spearman's rank correlation. The analysis proved significant (P<0.05) relationship between nutrient density and WF of the most relevant food items in Hungary. Based on the classification, there are nutrients that are overconsumed among the Hungarian population and positively correlate with WF (e.g., cholesterol) and there are nutrients that are under-consumed among the Hungarian population and negatively correlate with WF (e.g., dietary fibres). In general, it can be concluded that the re-structuration of food consumption patterns in Hungary is an important and urgent task, which serves both the public health and ecologic goals. These efforts should be based on a complex evaluation of the problem. This study was one initial step to analyse SN focused on Hungary and further studies are definitely needed.

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