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This paper presents the general features of parameter sensitivity maps and illustrates their practical use. We define parameter sensitivity maps as geoelectric responses in the measuring plane (at the surface) due to an elementary cube within the subsurface at three different depths. Responses of the three component as well as the total response of electrical dipoles formed on opposite cube surfaces are shown. In this paper we present such maps for 14 various linear electrode arrays. This paper is followed by an accompanying one about nonlinear and focussed arrays. Parameter sensitivity maps in these two papers provide a compact characterization of all known geoelectric arrays. We give several examples how to use them in planning and interpretation of field measurements.

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In this paper we present, at first time in a geophysical journal, parameter sensitivity maps of nonlinear and focussed electrode arrays. We present them as anomalies due to electric dipoles forming on opposing surfaces of an elementary cube within the subsurface at three different depths, and not only the total effect of the dipole, but also of its components are shown. Parameter sensitivity maps of non-linear arrays, compared to those of linear arrays, have in general 1. more equal sensitivity values in x and y directions, 2. more chances for antisymmetry axes, 3. smoother lateral distribution of sensitivity values. We recommend a systematic use of parameter sensitivity maps in geoelectric prospecting, both in planning and interpretation of field measurements.

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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 frames of a Hungarian Scientific Research Fund (OTKA) project (No. K49604), we systematically investigated all published surface geoelectric arrays, since a part of them are out of use, even completely forgotten. Even in case of these latter ones we were optimistic in their potential renaissance, due to the rapid advance in geophysical knowledge and technical development. Therefore at first we collected all surface geophysical arrays, ever used in geophysical exploration. We presented all of them in a standard way, and we classified them. This collection proved to be the basis of still on-going inter-comparisons. We revealed the original motivation of their design, as well. Then we produced parameter sensitivity maps for all possible arrays, by using a new analytical approach. Parameter sensitivity maps for non-linear and focussed arrays had never been presented before. Through examples (mainly for null-arrays, one of the focal points of our project) we presented, how these maps can be applied. Then another characterizing parameter, the depth of investigation was studied. The so-called depth of investigation characteristics (DIC) was computed for all the 30 arrays, where it exists, both in terms of Roy and Apparao (1971) and Edwards (1977). We carried out various comparisons, and revealed a complex relation among vertical resolution, depth of investigation and noise. We showed how the depth of investigation is constrained by the noise level. Therefore the maximal (theoretical) depths of investigation for 6 arrays were studied at various noise levels. Besides some further theoretical studies, our further work will concentrate on measurements. The general characterization of so many geoelectric arrays provides a better knowledge about them, and it will be hopefully useful also for other teams to select always the optimal arrays in their field problem. It should be mentioned, that this paper does not contain mathematical details. If the reader would like to reproduce the results demonstrated on the figures, the referred previous publications of the authors should be studied.

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Water and pollution transport takes places in fissures, and fissures may also reduce the stability of the rock body. Therefore, fissures in rock are an important issue, especially in case of multi-directional fissure systems, where the situation is more complicated.The so-called azimuthal technique, by using the Schlumberger array is a routinely applied method in geoelectric fissure detections. As we demonstrate it by using analogue model measurements, this method has several shortages. In absence of a priori information, the fissure directions could be obtained only in 60% of the total cases with a precision of ±10%. We have also demonstrated that the effectivity of the method becomes even worse, when the covering sediment layer is thicker. At the same time, when we simply rejected the anisotropy paradox, it was found, that the effectivity of the method is increasing with increasing sediment thickness. The original azimuthal technique is based on the generally accepted hypothesis of the so-called geoelectric anisotropy paradox. The analogue modelling results have made clear that the critical point of the method is the application of the anisotropy paradox. The fissure directions can only be determined, if the conditions of the anisotropy paradox are clearly defined. However, having more than one fissure directions, statistically these fissure directions can be correctly determined.

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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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The content and composition of active ingredients and essential oils in medicinal and aromatic plants have been studied for several decades. The volatile compounds in essential oils have been analysed routinely using gas chromatography (GC) since 1966, and with GC coupled to mass spectrometric detection (GC/MS) since 1978.The 13 rose varieties selected for chemical analysis varied for colour, shape and fragrance. The static headspace solid phase microextraction (sHS-SPME) technique recently developed for sample preparation and sample enrichment was used to study the volatile aromatic components.The main volatile compound of a sweet-smelling purple rose was found to be phenyl ethyl alcohol (33–52%). The phenyl ethyl alcohol content of fragrant rose flowers with blackish-purple petals increased continuously from early summer to late autumn (from 17 to 70 %). The dominant aromatic components of the yellow, orange and pink rose flowers were hexanol, hexenyl acetate and benzyl alcohol. Phenyl ethyl alcohol and orcinol dimethyl ether were the main constituents of the fragrant pink and white rose varieties. Methyl vinyl anisol and orcinol dimethyl ether were dominant in rose flowers with beige petals. In summary, it can be concluded that the SPME-GC/MS method is suitable for the characterization of rose varieties and for the chemical analysis of aromatic volatile compounds.

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Abstract  

An apparatus for natural tritium concentration measurement using an ethane-filled proportional counter with anticoincidence shielding is described. The counter characteristics and the counter calibration with internal tritium and external137Cs standards are discussed. Results of tritium analysis of Bratislava rains are presented.

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Acta Agronomica Hungarica
Authors:
É. Héthelyi
,
B. Galambosi
,
S. Szarka
,
É. Lemberkovics
, and
É. Szőke

The chemical contents of 47 herb and medicinal plant species cultivated in Finland during 2001–2011 were analysed in Hungary, and a total of 101 components were determined.The phytochemical evaluation of the herbs was aimed at interpretating the effects observed in acclimatization studies performed under Nordic climatic conditions. The phytochemical analysis was successfully applied for the quality control of medicinal, aromatic and culinary herbs, and provided numerous new scientific results (Acorus calamus, Artemisia abrotanum, A. paniculata, Gentiana lutea, Ligusticum scoticum, Perilla frutescens, Rhodiola rosea, Satureja biflora, Tagetes lucida). The results will provide useful guidelines for growers both in Finland and Hungary.

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Acta Geodaetica et Geophysica Hungarica
Authors:
A. Ádám
,
P. Bencze
,
J. Bór
,
B. Heilig
,
Á. Kis
,
A. Koppán
,
K. Kovács
,
I. Lemperger
,
F. Märcz
,
D. Martini
,
A. Novák
,
G. Sátori
,
S. Szalai
,
L. Szarka
,
J. Verő
,
V. Wesztergom
, and
B. Zieger

The paper describes research in geomagnetism and aeronomy carried out in the framework of a project organized by the Geodetic and Geophysical Research Institute of the Hungarian Academy of Sciences. It includes the development of the instrumentation of the Nagycenk Geophysical Observatory (geomagnetic measuring systems, ionosonde), moreover other instrumental and methodological developments, too. Observatory data are available in a database. Based on results of the Nagycenk and Tihany observatories and on data of permanent and temporal networks, long-term trends of different electromagnetic parameters were investigated. Thus geomagnetic activity was found secularly increasing, a decrease of the atmospheric electric potential gradient and a 11-year modulation of the winter/December attenuation of the geomagnetic pulsation activity were confirmed. Several possibilities (pulsations, whistlers, modelling) were used to improve knowledge about structure and parameters of the magnetosphere. Electromagnetic precursors of earthquakes were looked for. A significant increase of understanding was obtained in connection with Schumann resonances and electromagnetic transients caused by lightning. It was shown that see-coasts influence characteristically changes in ionospheric trends ( h m F2). When looking for the effect of the global climate changes in the subsurface electric resistivity, an example was discovered for the decrease of the resistivity due to infiltrating water from precipitation. Electromagnetic exploration of tectonically conditioned weak zones was continued, too.

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