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Although vitamin C is essential as an antioxidant and as a cofactor in a series of enzymatic reactions, the ability for ascorbate biosynthesis was lost in humans. Thus, horticultural products and derived fruit drinks or commercial vitamin C products are considered to be important sources for the ascorbic acid intake in the human diet. These facts underline the importance of analytical methods for ascorbic acid determination in different food products.

In our study two spectrophotometric and a fluorometric ascorbic acid determination methods have been compared with each other and with the so-called etalon HPLC method to find the best for small or middle sized food analytic laboratories with a sample number of up to several hundreds. As a result of our experiments we could establish that the OPDA-fluorometric method can be suggested for the determination of samples containing ascorbate at low concentrations. Unfortunately, the analytical properties of the OPDA method with spectrophotometric detection have been lagging far behind the others. The 2,2′-bipyridyl method could give a balanced performance for all tests. Furthermore, the results gained by this method are the closest to the results of the reference HPLC method in the case of fruit and vegetable samples.

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In the contact zone of three tectonic units (Pannonian Basin, Eastern Alps and Dinarides), in a complicated - basin and range - geological situation magnetotelluric deep soundings were carried out along a 140 km long profile\linebreak (CELEBRATION-007) with a site distance of 2 km. In this area deep fractures of the Basin run together in NE-SW direction. In the paper various magnetotelluric images completed with gravity and magnetics are provided. In the traditional magnetotelluric approach, the structural indication of the TM and TE mode magnetotelluric sounding curves is clearly separated. The TM mode curves well express the resistive basement structure, already known from dense boreholes and detailed seismic exploration. The TE mode curves on the other hand (together with the induction vectors of very low values) definitely show the conductive root of the deep fractures, where the ductile materials are assumed to be raised into a very shallow depth of about of 8 km. The high heat flow of the area (about 100 mW/m\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $^2$ \end{document}), which explains the shallowness of the conductive asthenosphere is also well indicated. The asthenosphere has more Alpine character in the NW part of the profile (its depth is about 80 km) and it is at smaller (about 50 km) depth in the SE part  of the profile, due to the higher heat flow near the extensional Drava Basin. The induction vectors are also separated into two characteristic regions, according to their general direction, influenced by both local and remote effects. A strong correlation is shown between magnetotelluric and gravity inversion results. A joint interpretation of magnetotelluric, gravity, magnetic results provide a quite comprehensive interpretation about the deep geological structures in SW-Hungary.

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Detailed magnetotelluric soundings along the Hungarian section of the CEL-7 seismic profile (SW Hungary, where a series of very deep 3D sedimentary basins is known from various geophysical-geological investigations) enabled us to produce magnetotellurics-based estimations for the topography of the high-resistivity basement. Both TM and TE modes were used for 1D inversion, and the resulting depth values were compared to the depths, taken from the “Pre-Tertiary Basement Contour Map of the Carpathian Basin” by Kilényi and Šefara (1989), called as K-S depths.

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This paper investigates the effect of electrode positioning errors on the inverted pseudosection. Instead of random spacing errors (as usually assumed in geoelectrics) we exactly measured this effect among field conditions. In the field, in spite of the greatest possible care, the electrode positions contain some inaccuracy: either in case of dense undergrowth, or varied topography, or very rocky field. In all these cases, it is not possible to put the electrodes in their theoretical position. As a consequence, the position data will contain some error. The inaccuracies were exactly determined by using a laser distance meter. The geometrical data from real field conditions and by using Wenner- α , Wenner- β , pole-dipole and pole-pole arrays were then considered over homogeneous half space.As we have found, the positioning errors can be regarded as insignificant, even in case of relatively uncomfortable field conditions. However, in case of very rocky surface the distortions are more significant, but it is still possible to make some corrections: either by neglecting a few electrode positions with the greatest positioning error, or to minimize the inline errors, even on the price that offline deviations are high.

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In order to investigate imaging properties of various magnetotelluric interpretation parameters over complicated models, we carried out numerical model calculations, where the models contained a 3D near-surface (``shallow") part and a 3D or 2D deep part. Various alternatively defined magnetotelluric responses, all of them based on rotational invariants of the magnetotelluric impedance tensor were considered. Then we calculated correlation coefficients between all these MT responses, and the characteristic geometrical parameters of the subsurface models, considered as a composition of “shallow+deep” elements.A systematic behaviour, similar to that had been observed in 1D situation was found: det(Re Z), Re det(Z) based apparent resistivity has the largest depth of  investigation and the best lateral resolution. Furthermore, besides the phase, the Re det(Z) (a twin-parameter of the phase) seems to give the most direct response about deep structures. In presence of 3D near-surface inhomogeneities the most surprising result is that there are narrow period windows, where the deep model can be directly seen in the Re det(Z) and in the phase responses.

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The authors present two cases of newborn babies infected by Trichomonas vaginalis (hereafter referred to as T. vaginalis) and suffering from severe congenital breathing difficulties and needing artificial respiration. Microscopic examination of the tracheal discharge revealed characteristically moving, flagellated, pear-shaped unicellular organisms. Cultures on CPLM medium proved the presence of T. vaginalis. During pregnancy the mothers' clinical status was negative and both of them mentioned leukorrhoea of changing intensity. They were regularly involved in antenatal care. The infection caused by T. vaginalis could be detected in the two mothers later by culture procedures.

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In the continuation of the CELEBRATION-007 deep seismic profile from Hungary to Austria a series of deep magnetotelluric soundings has been carried out, using the instruments (from GFZ MT instrument pool). In spite of the high noise level, the relatively good imaging of the structure of the sedimentary Graz Basin and possibly fluid filled conducting fractures in the resistive rock matrix of the Eastern Alps have been indicated. They might be potential source of geodynamics (earthquakes?).

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Firstly the authors give an overview on the geological, geophysical and tectonical features of the Diósjenő  dislocation belt (or zone, according to some authors) around the river Ipoly near the Hungarian-Slovak border among great structural units: Vepor, Gemericum and formations of the Mid Hungarian Mts. The longest magnetic anomaly of the Pannonian Basin lies in this belt. It is assumed that it is due to ultrabasic magmatite of greenschist facies. The near-surface geoelectric soundings did not find any conductivity increase near Diósjenő  (western part of the zone), but there are graphitic micaschists in the boreholes around Szécsény. There is some earthquake activitiy in the region with hypothetical depth of 7-8 km. Two deep magnetotelluric (MT) profiles cross the dislocation zone. The resistivity distribution from the surface to the conductive asthenosphere along these profiles was obtained by using instruments, operating in two different period ranges. After processing the measured data by 1D/2D inversion, it became obvious that the dislocation zone includes electrically conducting roots at a depth of 7-11 km. This result hints at the presence of fluid in the broken rocks having increased porosity in the dislocation zone. Another component that can increase the conductivity could be the graphite (carbon) originating from the Paleozoic crystalline rocks of the Gemericum (or Vepor). The ductile phase (fluid/graphite) observed by high conductivity in the centre of the dislocation zone can play an important role in the generation of the earthquakes according to the most recent statements of the international literature.

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In this paper we provide a comprehensive summary about the practical results of the OTKA project K49604. 1. We calculated the consequences of incorrect positioning of the electrodes for various multielectrode systems. In practice these effects were found to be negligible. The only exception is the case of rocky surface, where it is impossible to put the electrodes in the desired positions. The errors can however be kept within an acceptable range, if the electrodes of the linear arrays are put off-set, at right angles from the measuring line. A five-six times larger off-set has less effect than a certain mis-position along the line, connecting the electrodes. 2. We carried out tensorial geoelectric measurements around the Cistercian Monastery at Pilisszentkereszt. Areal measurements provide much more detailed and unambiguous anomalies than 2D profile measurements, and the tensor invariant representation of apparent resistivity anomalies provides a realistic picture about the lateral variation of the subsurface resistivity, even in field circumstances. 3. We tested the applicability of 3D electrical resistivity tomography (ERT) technique to detect landmines in different soil conditions and at various depths. Metallic and non-metallic landmines buried in wet and dry soils had been synthetically modeled. According to the inverted resistivity data using the dipole axial array in wet environment, it was possible to locate the metallic and non-metallic landmines as long as the noise level was about 5%. 4. We elaborated moreover a geoelectrical procedure which is able to map multidirectional fissure systems by combining geoelectrical profiling and geoelectrical azimuthal measurements. Results received by using both the so-called null-, and traditional arrays were jointly interpreted. The humidity of the fissures affects the measured results significantly, and in a meaningful way. 5. We presented the socalled standardized pricking probe (PP) surveying technique and demonstrated its usefulness in an archaeological study. The PP images proved to be definitely more close to the realistic shape of the buried chapel than the geoelectric and magnetic measurements, and they also revealed more details about the subsurface than the georadar. The optimum PP parameters: horizontal interval, pricking depth, observable quantity and its way of presentation were optimized through field experiments. For more details see the cited publications. The figures ever published in Hungarian journals are not reproduced here.

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