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Alunites from the low sulfidation-type epithermal systems of the Tokaj and the high sulfidation-type epithermal systems of the Velence Mountains were compared in terms of mineralogical and genetic aspects Na-enriched (1.14 to 2.35% Na2O) tabular alunites from the advanced argillic alteration zones of the Velence Mountains appear in the cavities formed from leached phenocrysts of andesitic rocks. These magmatic-hydrothermal alunites display compositional zoning due to variation in Na and K content and contain Ca-rich phosphate-sulfates with REE elements in their cores (i.e., woodhouseite series). The source of P is probably magmatic apatite that dissolved during intensive leaching of the host rock by acidic magmatic-hydrothermal fluids. Alunites in the steam-heated alteration zones of the Tokaj Mountains appear in the cavities formed from leached pumice fragments of rhyolite tuff units or in fractures in altered rhyolite domes. Rhombohedral and platy alunites have minor Na content (0.02 to 0.61%Na2O) and display compositional zoning due to the variation in Ba content. However, comb alunites contain more Na (1.55 to 1.82% Na2O) and compositional zoning can be attributed to variation of Na and K content. Alunites from the Velence Mountains have much higher d34S values (24.2 to 25.3‰) compared to alunites from the Tokaj Mountains (4.7 to 8.6‰). The d18O values for the sulfate site in the alunite structure are between 10.6 and 13.6‰ in both areas. High d34S values can be attributed to S isotope fractionation during the high temperature magmatic-hydrothermal formation of alunite from the Velence Mountains, which did not occur during formation of low-temperature steam-heated alunites from the Tokaj Mountains.

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The radio limb sounding or occultation technique is capable of deriving accurate vertical profiles of atmospheric refractivity. This has been shown by very promising results of the first active GPS limb sounding GPS/MET experiment on Microlab 1. In this paper we report early results of ionospheric radio occultation (IRO) measurements carried out onboard the German satellite mission CHAMP (CHAllenging Minisatellite Payload) that contributes also to essential improvements of gravity and magnetic field models of the Earth.  First radio occultation measurements of the ionosphere were carried out by CHAMP on 11 April 2001.  Fortunately, ionospheric radio occultation measurements were switched on during the High Rate GPS/GLONASS  measuring campaign (HIRAC) initiated by the International GPS Service (IGS) and supported by COST 271 activities. So a comprehensive analysis of coordinated measurements will be possible within COST 271 cooperation in the near future.  The achieved accuracy of the retrieved electron density profiles is estimated by comparing them with independent ionosonde data.

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In this paper we provide a field example for the determination of the location and direction of fissures in narrow, elongated measuring areas. The test measurements were carried out on the Mokattam plateau at Cairo (Egypt). Direction, length of the layout and the profile length all were very limited, since the measurements had to be carried out within a narrow (2-10 m wide) stripe, between a built-in area and a cleft rim. Interpretation of field measurements was supported by (1) analogue model experiments, and (2) parameter sensitivity maps. As it was found from laboratory experiments, fissures are indicated by potential-difference maximums along profiles measured by using three-electrode array (if the reference point is between the potential electrodes). The mean distance between two neighbouring maximums throughout the whole profile was found to be about 3-4 m, corresponding to the distance between the most visible fissures on the cleft wall. The Schlumberger null-array has been found to be an appropriate tool in determination of the direction of fissures. Its resolution is higher than that of the classical Schlumberger array. Its only disadvantage is that on the azimutal diagram it gives two times more minimum pairs than the number of fissures. Among such constrained circumstances the best method to get useful information about location and direction of fissures in the subsurface limestone is to use jointly corresponding traditional and null-arrays. While the location is given best by traditional three-electrode array measurement, the direction of the fissures is given from the joint interpretation of the Schlumberger null-array and the traditional Schlumberger array. In this way it is to separate several fissure directions.

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The ionosphere region plays an active role in the complex space weather relationships. So a permanent monitoring of the ionospheric state on global scale is required. The world-wide use of Global Navigation Satellite Systems (GNSS) such as GPS and GLONASS offer the unique chance for a permanent monitoring of the total ionization (Total Electron Content -- TEC) of the global ionosphere/plasmasphere up to about 20000 km height.  In this paper we focus on space weather phenomena on 6--7 April 2000 in the ionosphere based on GPS, GLONASS and ionosonde measurements over Europe and over the northern polar cap. Depending on the density of the actual ground station distribution the horizontal resolution of the derived TEC maps is in the order of 500--1000 km. While discussing the special space weather event on 6--7 April 2000 it will be shown that TEC is very sensitive to perturbation induced dynamic forces such as particle precipitation, electric fields and meridional thermospheric winds. We suppose that the strong impact on the magnetosphere/ionosphere systems is due to the southward direction of the interplanetary magnetic field in the evening hours of 6 April. The ionosphere impact on navigation signals is demonstrated by analyzing 1Hz sampled data of GPS and GLONASS satellites. The derived signal phase irregularities due to ionospheric irregularities that degrade navigation and positioning applications indicate highly variable horizontal  structures.

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In addition to the original equipment, a new measuring set has been constructed for observing the atmospheric electric potential gradient (PG) at Nagycenk station. The study describes this new set and reports on PG variations derived from data obtained by the two simultaneous measurements. Both runs of the mean diurnal variations determined on the basis of the two data sets are quite similar, as well as they resemble the appropriate diurnal variation derived from earlier Nagycenk data, or fairly the `Carnegie Curve'. Nevertheless, the measured PG level is somewhat higher in the case of the new equipment (PG 2) than that measured with the original set (PG 1). This is also true in the case of single days diurnal variations, however, the daily runs derived from the individual measurements are hardly different. Whichever of the two data sets is applied, the PG's seasonal (annual) variation shows a distinct maximum in winter, even if this maximum is again higher for PG 2 than that for PG 1. Certain ideas on this behaviour are also suggested by the study

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Our data verified the relationship between meteorological factors and the fluctuation of the groundwater level. The rate of evaporation dominantly affected the rise and depth of the groundwater level. It is characteristic for the study site that there is an inverse relationship between the elevation of the groundwater observation wells and the depth of groundwater, and the difference between the levels of groundwater in the separate wells reflected the differences in the elevation between the wells. Our observations refuted our previous assumptions, as in the wells not only the concentration of salts changed but also the chemical type of the water. This can be attributed with great probability to the lateral flow of the groundwater, which is caused by the vertical fluctuation, but can be caused by other geological factors as well. We reached the conclusion that the vertical and sometimes lateral movement of the groundwater affects the development of soils in a given area. It means that the reason behind the mosaic-like appearance of the soil cover of a given area can be searched in the local differences of the chemical composition of the groundwater, which is a major factor of the spatial variability of the salt accumulation of soils. The observations and analytical results point to that the soils of the study site have developed under the effect of fluctuating groundwater and the elevation is a dominant factor of the spatial variability of the soil salt accumulation. The level of groundwater, the flow of groundwater and its composition show relationship with the surface elevation, and their effect is modified by the geological stratification, which results in a variable appearance of soil salt accumulation and native vegetation.

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New, quantitative methods and data sources for characterizing small scale soil resources have been demonstrated. AVHRR and coarse spatial resolution DEM were designed for mapping large areas of the world quickly and cost effectively. The method combines digital elevation data, “ground truth” information, including the soil taxonomic class for measured soil locations, and a time series of satellite images to form a digital soil database. The results show that using ancillary information such as AVHRR data and DEM derivatives from the national to continental level surveys is among the most promising tools for geographers and soil surveyors. The AVHRR data is often used for land cover studies but its usefulness in soil studies has not yet been proven. This study is a representative example of the usefulness of AVHRR data in characterizing the soil-forming environment and delineating soil patterns, particularly when integrated with other data for describing the soil landscape, such as the DEM, slope, curvature and PDD. The predictive power of AVHRR and similar low spatial resolution satellite data sources could be further improved with the development of soil sensitive filters. Mention should be made of the potential improvement of the products derived from these data sources with the use of better quality data provided by satellites that have been launched recently. Neither the AVHRR nor the DEM-derivatives show high correlation with the soil classes, but both represent a great portion of the environmental variability. In general, the more uncorrelated information is extracted from DEM and AVHRR, the better explanation of the spatial soil variability is achieved with an integrated use of them. The images of AVHRR time series show a relatively low correlation, thus each of the new dates adds much potential information on the soils. The studies also highlighted the great help of surface vegetation in soil remote sensing, as indicated by the high R² value of Band 1 and NDVI. The importance of the short-term weather history of the study area was also demonstrated.  Terrain information and terrain variables were primarily developed for large scale local studies. Small scale mapping of large regions presents different issues, like over-generalization and over-smoothing of the soil information. The terrain features with smaller extents are dissolved into a larger neighborhood. As a smoother terrain map is created, a lot of detail is lost and less variability is observable. Many of the terrain attributes are useless with this approach. Elevation, slope, relief intensity, potential drainage density and the curvature variables are the most informative digital variables for characterizing the soil-landscape in small scale inventories.  The resulting soil databases will have all the advantages of quantitatively derived databases, including consistency, homogeneity, and reduced data generalization and edge-matching problems. Although the results from the above procedures are believed to be accurate enough to serve as a basis for global and regional studies, they should be checked and further revised by local and regional experts to ensure quality. Research should continue on improving the procedures, augmenting the pedon data with new field sampling, and incorporating new image and DEM data sources. One of the most important results of these studies is the demonstration of the usefulness of these data sources for small scale soil mapping and the overall validity and representatitivity of the AVHRR-terrain/soil correlation within the temperate region of the world. Further studies will need to be performed to test the use of AVHRR and terrain data for other climate zones of the World, where potential problems, like continuous cloud cover, may occur.

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Soil texture is an important input parameter for many soil hydraulic pedotransfer functions (PTFs) of the day. Common soil particle-size classes are required to be able to uniformly determine the texture of soils. However, it is not always possible - due to different national classification systems - and much valuable information is disregarded while either deriving or applying PTFs. One way to get common particle-size class information is to interpolate the particle-size distribution (PSD) curve. Advanced interpolation solutions are becoming available, but there is always uncertainty associated with these techniques. Another possibility is to measure all PSD curves in such a way that it is compatible to the commonly used classification systems. A new automated measurement technique is introduced that can easily provide PSD data compatible to any (and all) of the existing national and international classification systems at the same time, without the burden of extra labour. A computerized measurement system has been developed to record density changes in a settling-tube system in any discretional (small) time steps, which in turn allows the derivation of a quasi-continuous PSD curve. The measurement is based on areometry (Stokes-law), thus the system is compatible to the most commonly applied settling-tube measurements. The new evaluation method of measured values takes into consideration the density changes along the areometer-body so it avoids the problem of reference point determination. The theory and setup of the system are explained and measurement examples are given. The presented comparative measurements show good correspondence with conventional settling-tube results, and the reproducibility of the measurement shows to be very high. This technique does not require more sample preparation than past methods. The automated reading requires less manpower to perform the measurement - which also reduces human error sources. However, it provides very detailed PSD data that has advantages, like revealing multi-modality in the particle-size distribution or providing data that complies with any of the classification systems.

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Agrokémia és Talajtan
Authors: Barbara Simon, E. Michéli, G. E. van Scoyoc, and et al.

The Typic Haplustalfs soils (Karád and Oltárc) and the Typic Ustochrepts (Gödöllő) are developed on loess, and on aeolian sand parent material, under forest vegetation, resp. The Dystric Ustochrepts (Velem) soil formed on metamorphic schist parent material and had forest vegetation, while the Typic Medisaprists (Zalavár) soil developed on peat parent material and had marsh vegetation.   Based on this study the spatial variability of surface pH samples indicate that the TIM sampling procedure should be improved. Ten to thirty samples must be collected at each site to be able to monitor changes of 0.2 pH units. If only one sample is taken at each site yearly, spatial difference in pH or other parameters are likely to obscure differences which may be occurring over time.  The colloidal composition (organic matter and clay minerals), influenced by parent material, vegetation, and precipitation, showed a close relationship with the acidity factors, such as pH, HAC 1 and EAC 1 values. The pH values were the lowest in the Velem and Oltárc soils where the annual precipitation was the highest (750-800 mm), and in the Karád soil, where the annual precipitation was 650-700 mm. The Gödöllő soil had the highest pH values, probably due to the lowest amount of rainfall (550-600 mm) and the disturbance. The Zalavár soil had fairly high pH throughout the profile probably due to a fluctuating water table.   The HAC 1 and EAC 1 values were the highest in the Velem soil when compared to the other mineral soils.  The pH values were the lowest at this site. The HAC 1 and EAC 1 values were lower in the other three forest soils, at the Karád, Oltárc, and Gödöllő sites. The Zalavár soil had fairly high HAC 1 values in the H3, H4 and H5 horizons, probably due to the very high OM content, which provided a lot of H + ions that can dissociate from the exchange sites.   The E4/E6 ratios were closely related to the decomposition or humification rate in the upper and the subsurface horizons with accumulation of low molecular weight soluble fraction in the deeper horizon.   The mineralogical analysis showed similar compositions for the soils developed on loess (Karád and Oltárc), or aeolian sand (Gödöllő), where the major minerals were vermiculite, mica, kaolinite, and chlorite. A different mineral composition (mica, vermiculite, clintonite, and kaolinite) was observed for the Velem site, where the parent material was metamorphic schist. The four mineral soils are forest soils, with a predominant downward water movement, thus with fairly intensive leaching process. However, there was a distinct difference among the soils formed on loess (Karád and Oltárc), or aeolian sand (Gödöllő), and the soil (Velem) developed on metamorphic schist parent material.  The soils at the Karád, Oltárc, and the Gödöllő sites were less acidified, with higher pH, and lower HAC 1 , and EAC 1 values as compared to the Velem soil, even if the precipitation was very high. The calcareous loess parent material probably compensated for the higher precipitation and the resulting leaching process at the Karád and the Oltárc sites. The Gödöllő soil received a very low amount of precipitation, which resulted in a low degree of weathering, with higher pH, and lower HAC 1 , and EAC 1 values. However, the metamorphic schist parent material probably contributed to a lower pH and lower buffering of the developing soil.   Based on the chemical and physical analyses, we concluded that among the soil forming factors, precipitation and parent material had the greatest influence on the acidity characteristics of the examined soils. The parent material influenced the mineralogy of the developing soil, which then influenced the pH, HAC 1 , EAC 1 , and CEC values of the soil. In order to substantiate these tendencies more samples from a wider array of geological regions are needed.   

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Authors studied the effect of copper nutrition on the yield, kernel weight and raw protein content of winter wheat. Copper was applied in the form of copper tetramine hydroxide that was produced from a clean copper containing waste originating from microelectronical industry. After suitable chemical transformation this waste can be used as an excellent secondary raw material for the preparation of copper fertilizer. The foliar application of copper tetramine hydroxide complex at the phenological phase of tillering significantly increased the yield, kernel weight and raw protein content of winter wheat. The calculated copper doses that gave the maximum yield, raw protein content and kernel weight were 1.04, 1.12 and 0.77 kg ha -1 respectively.

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