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  • Author or Editor: A. Németh x
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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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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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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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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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A new nuclear excitation process,99Tc (, )99mTc reaction, was applied for the first time to radioactivation analysis of technetium. Bremsstrahlung irradiation of99Tc samples gave the reaction product99mTc which emits -ray measurable with ease by a semiconductor detector. The production rate of99mTc per g99Tc was linearly correlated with the flux of bremsstrahlung. The detection limit of99Tc was estimated to be nanogram order (0.63 Bq99Tc) under the optimum irradiation condition. Possible interference by100Ru(, p)99mTc reaction was also studied, which could be discriminated from the (, ) reaction by simultaneously occurring98Ru (, p)97Ru reaction.

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The Sopron Wine Region is one of the most significant and historical wineproducing regions in Hungary, with a total area of 4300 hectares, out of which 1800 hectares are used for grapevine cultivation. The aim of the present research was to carry out basic measurements for soil, grape and wine in the Sopron Wine Region to obtain preliminary results for future investigations.The demonstrated methods are suitable for the combined analysis of soils, grape berry and wine. It was established that there are differences between the composition of grape berry and wine of the selfsame vine cultivar in the investigated areas. The terroir effects of the Sopron Wine Region have not been studied as yet extensively, although there are several international studies in this field (e.g. Hugget, 2006; Csikász-Krizsics & Diófási, 2008; Fernández-Marín et al., 2013). By future measurements carried out on a large number of samples and with sophisticated multivariate statistical analysis the relationships between measured physical and chemical parameters can be evaluated in the region, providing basis for establishing terroir aspects.

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Abstract  

57Fe-conversion electron Mössbauer spectroscopy (CEMS) — a sensitive tool to analyze the phase composition of corrosion products on the surface of stainless steel — was applied to study real specimens from the Paks Nuclear Power Plant, Hungary. The primary circuit side of the heat exchanger tubes was studied on selected samples cut out from the steam generators during regular maintenance. Mostly Cr-and Ni-substituted magnetite, amorphous Fe-oxides/oxyhydroxides as well as the signal of bulk austenitic steel of the tubes were detected. The level of Cr-and Ni-substitution in the magnetite phase could be estimated from the Mössbauer spectra. It is suggested that Cr-Ni substitution occurs simultaneously so that the inverse spinel structure of magnetite is preserved up to a certain limit which appears to be roughly at [Fe3+]tet[Fe2+ 1/4Ni2+ 3/4Fe3+ 1/4Cr3+ 3/4]octO4. Further decrease of the iron content of this phase results in the formation of nickel chromite of regular spinel structure, with very low Fe content. This transformation may be responsible for the hybrid structure of the protective oxide layer, being substantially accelerated by previously performed, factory developed and proposed AP-CITROX decontamination cycles.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: G. Fürjes, G. Tóth, B. Peitl, R. Pórszász, B. Lelesz, R. Sári, A. Tóth, Z. Szilvássy and J. Németh

Abstract  

In the present paper the development and application of a novel thrittene radioimmunoassay (RIA) are described. 125I-labeling of Tyr(0)-thrittene was performed by the iodogen-method and the mono-iodinated peptide, as RIA tracer, was separated by reversed-phase high performance liquid chromatography (HPLC). The RIA results show that the antiserum used in the radioimmunoassay turned to be C-terminal specific, without significant affinity to other members of the somatostatin peptide hormone family. Detection limit of the assay was 0.2 fmol/ml. This highly specific and sensitive thrittene RIA was used to investigate the distribution of thrittene in the rat gastrointestinal tract and other tissue samples. Different areas of the gastrointestinal tract and other tissues were removed from rats and after extraction the samples were processed for thrittene radioimmunoassay. Highest concentrations were found in the duodenum samples followed by jejunum and ileum, however, all the examined tissues contained highly enough thrittene for the measurement.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: J. Németh, B. Jakab, R. Józsa, T. Hollósy, A. Tamás, A. Lubics, I. Lengvári, P. Kiss, Zs. Oberritter, B. Horváth, Z. Szilvássy and D. Reglődi

Abstract  

Pituitary adenylate cyclase activating polypeptide (PACAP) is a widely distributed neuropeptide that has two molecular forms with 38 and 27 amino acid residues. The aim of the present study was to develop a new, highly specific PACAP-27 assay to investigate the quantitative distribution of PACAP-27 in the central nervous system of various vertebrate species applying the same technical and experimental conditions. Our results show that the antiserum used turned to be PACAP-27 specific. The average ID50 value was 51.5±3.6 fmol/ml and the detection limit was 2 fmol/ml. PACAP-27 immunoreactivity was present in the examined brain areas, with highest concentration in the rat diencephalon and telencephalon. Swine and pigeon brain also contained significant amount of PACAP-27. Our results confirm the previously described data showing that PACAP-38 is the dominant form of PACAP in vertebrates, since PACAP-38 levels exceeded those of PACAP-27 in all examined brain areas. Furthermore, our study describes for the first time, the comparative quantitative distribution of PACAP-27 and-38 in the swine and pigeon brain.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: Z. Németh, Z. Homonnay, F. Árva, Z. Klencsár, E. Kuzmann, J. Hakl, K. Vad, S. Mészáros, K. Kellner, G. Gritzner and A. Vértes

Abstract  

In this paper we present 57Co emission Mössbauer and AC magnetic susceptibility studies of La0.8Sr0.2CoO3-δ perovskite. The observed coexistence of paramagnetic and magnetic subspectra in the 57Co emission Mössbauer spectra, as well as the difference of their isomer shifts support the existence of electronic phase separation in this perovskite, in good agreement with the double exchange based cluster model.

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