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  • Author or Editor: L Szabó x
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Abstract  

We prove that the family of all invariant sets of iterated systems of contractions R N R N is a nowhere dense F σ type subset in the space of the nonempty compact subsets of R N equipped with the Hausdorff metric.

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Secondary sexual characteristics such as softening and rounding of the abdomen as well as reddening and protrusion of the anal papilla and vent can be of help to breeders in selecting common carp (Cyprinus carpio) females prepared for propagation. To assess the reliability of this method, long-term data obtained on induced spawning of common carp at a large-scale fish hatchery were evaluated. The average spawning ratio of 2,620 females receiving hormonal injections was 79.8%. The average pseudogonadosomatic index (PGSI) calculated from data on the egg production of 2,086 females was 16.3 ± 5.87% (mean ± SD) for the same period. There was a correlation between fish weight and the time of induction determined by the breeder on the basis of external morphological characteristics. The similarity of the responses of females, including both spawning ratio and PGSI, among the different weight categories proved the reliability of this method for identification.

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Papaver somniferum produces secondary metabolites, which have important roles in their self-defence processes, in plant biochemistry and in allelochemistry. We can see that different stress effects change the quantity of alkaloids. The object of the experiments is, in what manner changes the content of alkaloids of poppy in case of irregular stress effects. Papaver somniferum (cv. 'Kék Duna', Budakalász) plants were grown for 2 months from seeds in quartz-sand (in natural light, temperature: 24-28 °C, in Knop's nutritive solution). In this paper we studied the alkaloid of poppy treated with two kind of stress factors: mycotoxin and drought, respectively. Both the quantity and the spectrum of alkaloids were measured after different separation procedures. Thin layer chromatography (TLC and HPTLC) and high performance liquid chromatography (HPLC) were applied. Content of the level of formaldehyde (HCHO) also increases in plants with different stress effects. Our presupposition is that the formation of methyl groups of poppy alkaloids takes place through HCHO. It gave us an opportunity to examine changing of formaldehyde (HCHO) level in biotic and abiotic stress situation. Formaldehyde in dimedone adduct form can be detected in injured tissues of Papaver somniferum. As a consequence, the stress effects can be detected in poppy plants by two kinds of method. At first we measured content of alkaloids. Drought stress produced a higher level of the alkaloids, but the mycotoxin stress did not show significant results.

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Energy saving in buildings is one of the most important research directions in the building sector. Energy saving solutions should not lead to decreased indoor environment quality. Because of the increased number of summer heat waves, cooling systems are widely used to assure thermal comfort in buildings. In this paper, ceiling cooling and wall cooling systems were tested and compared from the thermal comfort point of view using 24 subjects (12 women and 12 men). The cooling ceiling and wall surface and the supply/return temperatures were similar. Analysing the obtained subjective answers, no significant differences were obtained on average or by gender. However, significant differences were obtained between the subjective answers and the calculated PMV values. Furthermore, the occupant’s reaction was different after switching off the ventilation and cooling systems.

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Abstract  

The magnetic properties of poly(3-dodecyl-thiophene) (PDDT) irradiated by -beams have been studied by measuring the magnetic susceptibility and EPR spectra. The irradiated PDDT is characterized, similarly as the non-irradiated one, by an antiferromagnetic course of magnetic susceptibility with a Néel temperature of 237 K. It is suggested that the antiferromagnetic properties of PDDT are caused by transformation of polarons to bipolarons, which takes place at lower temperatures.

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The national soil-mapping project initiated and led by Kreybig was unique being a national, large-scale survey based on field and laboratory soil analysis and in the meantime serving practical purposes. By its completion, in the early 1950s, Hungary was the first country in the world having such detailed soil information for the whole country. The Kreybig maps are still timely, because the temporal changes in the mapped soil characteristics are not significant. The GIS adaptation of information originating from this survey is under construction, but there is more utilizable information originating from this survey, than it was published in the map series and in reports, and what is provided by simply archiving them digitally. Compilation of the Digital Kreybig Soil Information System as a national spatial soil information system involves both its integration within appropriate spatial data infrastructure and updating with efficient field correlation, which make an inherent refinement and upgrading of the system possible. The field-based updating of DKSIS using field GIS technology by the implication of recent data collected at revisited sites makes the comparison of archived and newly surveyed soil state possible. This, in one hand, should be recorded in the database by updating it. On the other hand, trends can be identified in soil characteristics, thus processes can be realized and/or forecasted. Based on the upgraded database we produce soil maps (i) displaying recent state of soils (ii) with increased accuracy and (iii) according to the soil-mapping concept elaborated by Kreybig et al.

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Abstract  

The influence of -radiation on the d.c. conductivity of poly(3-hexadecylthiophene) (PHDT) doped with FeCl3 in chloroform, toluene, ethanol and nitrobenzene atmospheres has been studied. A different course of d.c. conductivity changes taking place in the atmosphere of solvent vapors (chloroform, toluene) and precipitants (ethanol, nitrobenzene) has been found. The character of changes can be influenced by polymer cross-linking initiated by -radiation.

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