Mineralogy,alteration patterns,geochemistry, and fluid properties of the Ag-Au epithermal deposit Nová Baňa,Slovakia     

Majzlan  Juraj  Berkh  Khulan  Kiefer  Stefan  Koděra  Peter  Fallick  Anthony E.  Chovan  Martin  Bakos  František  Biroň  Adrián  Ferenc  Štefan  Lexa  Jaroslav 《Mineralogy and Petrology》2018,112(1):1-23

Mineralogy and Petrology - In this contribution, we report new data on mineralogy, alteration patterns, geochemistry, fluid properties and source of fluids for the deposit Nová Baňa, one...  相似文献   

Evaluation of Pumping Induced Flow in Observation Wells During Aquifer Testing     

Ferenc Székely 《Ground water》2013,51(5):762-767

The vertical variation of drawdown around pumping wells generates an induced flow in the observation wells. A set of governing equations is presented to couple the drawdown variation and the vertical flux distribution in observation wells. A numerical example is performed to justify the governing equations and to verify the solution methods used by the simulation software WT. The example analyzes the effect of skin loss, wellbore storage, and vertical segmentation on the drawdown and induced flow in observation well during pumping. The evaluation of the Fairborn pumping test involves a vertically homogeneous and anisotropic water table aquifer, uniform well‐face drawdown conditions in the pumping well and simulation of the drawdown evolution in the observation well with and without the effect of induced flow. The computer calibrations resulted in small differences between the measured and simulated drawdown curves.  相似文献   

Short Time Lyapunov Indicators in the Restricted Three-Body Problem     

Zsolt Sàndor  Róbert Balla  Ferenc Téger  Bálint Érdi 《Celestial Mechanics and Dynamical Astronomy》2001,79(1):29-40

We applied the method of the short time Lyapunov indicators to the planar circular and to the planar elliptic restricted three-body problem in order to study the structure of the phase space in some selected regions. In the circular case we computed the short-time averages of the stretching numbers to distinguish between regular and chaotic domains of the phase space. The results obtained in this way are in good agreement with the corresponding Poincaré's surface of sections. Using the short time Lyapunov indicators we determined the detailed structure of the phase space in the semi-major axis-eccentricity plane of the test particle both in the circular and in the elliptic restricted problem (in the latter case for some values of the eccentricities of the primaries) and we studied the main features of the phase space.This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

Assessment of Regional Variations in Biomass Production Using Satellite Image Analysis between 1992 and 2004     

Ferenc Kovàcs 《Transactions in GIS》2007,11(6):911-926

As a consequence of the increasing aridity experienced in Hungary in the past decades, any future spatial planning decisions should consider the threat of an arid environment. For identifying sensitive and endangered areas, suitable methods should be developed. These could help those responsible for decision making in providing quick and suitable actions in planning. Through the investigation of vegetation, regional scale variations in the landscape along with the responses of forests to climatic changes can be easily detected. Our primary aim was the evaluation of the natural water supply on the Danube Tisza Interfluve by studying the forests, meadows and pastures of the area in the summers of 1992 and 2004. We investigated with the help of remote sensing the short‐term response of vegetation to the altered environmental conditions. According to the spatial and temporal analyses of vegetation indices (NDVI) based on AVHRR and MODIS images, a considerable decrease in the activity of vegetation can be observed throughout the entire vegetation period. Due to the suspected climatic changes, 33% of the studied vegetation might be endangered.  相似文献   

The land-surface flux model PROGSURF     

Ferenc cs  Michael Hantel 《Global and Planetary Change》1998,19(1-4)

The land-surface flux model (PROGSURF) designed jointly at the Universities of Vienna and Budapest is reviewed; it belongs to the broad spectrum of PILPS¹ models. PROGSURF comprises one vegetation layer and three soil layers. Temperature prediction is made by the heat conduction equation in conjunction with the force-restore method. Turbulent heat fluxes are parameterized by gradient laws using the resistance concept. The formula for the canopy surface resistance involves both a parameter describing atmospheric demand and one describing moisture availability. Soil moisture prediction is made with Richards' equation. PROGSURF is tested in off-line mode for the Cabauw data set. The observed annual mean values of the state and flux quantities at the earth's surface are well reproduced. For example, the model yields latent and sensible heat fluxes of −35.3 and −2.4 W/m², respectively; evapotranspiration and runoff is −449 and 326 mm/yr; and root zone soil moisture content is 0.344 m³/m³. Further, the seasonal changes of water and energy balance components are well simulated. The sensitivity of PROGSURF to the canopy resistance formulation is analysed. We find that the atmospheric demand is largely represented by the saturation value of the evapotranspiration/soil moisture curve with maximum summer impact upon the annual value and further that the moisture availability is represented by the slope of the evapotranspiration curve. Both saturation value and slope control the amplitude of the seasonal fluctuation of the water balance components; at Cabauw site the saturation value is the governing parameter. These results fit satisfactorily into the other PILPS models. In particular, we are able to reproduce with PROGSURF the total variability of most other PILPS models by simply changing the atmospheric demand and soil moisture availability parameters. PROGSURF presently serves to simulate observed surface fluxes for an atmospheric diagnostic model.  相似文献   

Adaptation and the Guardrail Approach to Tolerable Climate Change     

Gary Yohe  Ferenc L. Toth 《Climatic change》2000,45(1):103-128

Windows delineating tolerable or "acceptable" conditions associated with climate change can be defined in terms of a variety of parameters; a preliminary window offered by the Scientific Advisory Council on Global Change of the Federal Government of Germany sets limits on temperature change and the rate of temperature change. Investment in adaptation can alter the size and shape of these windows, and different emissions trajectories are associated with different limiting points on their boundaries. As a result, the value of adaptation depends upon both the underlying structure of the tolerable window and the basecase emissions trajectory. Given uncertainty about both, the best near-term policy should be cast in a sequential decision-making framework. Seen in this light, improved adaptive potential can either reduce the cost of sustaining tolerable climate change or increase the opportunity cost of holding to more restrictive boundaries.  相似文献   

Preliminary analysis on roles of metal–organic compounds in the formation of invisible gold     

Junussov  Medet  Ferenc  Mádai  Ferenc  Kristály  Tivadar  Tóth  Krisztián  Fintor  Gábor  Muránszky  Ádám  Prekob  Mária  Hámor-Vidó 《中国地球化学学报》2021,40(6):1050-1072

The paper comprises new analytical data on the nature and occurrence of gold in solid pyrobitumen, closely associated with the main gold-bearing sulfide arsenic ores of the Bakyrchik gold deposit (Kazakhstan), related to post-collisional magmatic-hydrothermal origin. Gold mineralization of the deposit occurs mainly in the form of an “invisible” type of gold in the structures of arsenian pyrite and arsenopyrite, and the form of gold-organic compounds of pyrobitumen in carbonaceous-terrigenous sequences of Carboniferous formation. Microscopic and electron microscopic analysis, Raman and FT-Infrared analysis, mineralogical and three-step sequential extraction analysis (NH₂OH·HCl, H₂O_2, HNO₃ + HCl) has been carried out using 9 ore samples (from 3 different types of ores) for a comprehensive study of pyrobitumen and sulfide arsenic ores focusing mainly on organic matter. The sequentially extracted precious metal content of pyrobitumen reaches up to 7 ppm gold and other metals like Ag 4 ppm, Pt 31 ppb, and Pd 26 ppb, forming metal–organic compounds, while arsenic sulfide minerals incorporate 11 ppm gold, 39 ppm Ag, 0.49 ppm Pt. The enrichment of gold associating with organic matter and sulfide ore minerals was confirmed in this study. Organic matter was active in the migration of gold and the capture of gold by pyrobitumen. Moreover, the reductive organic matter agent released gold, most likely for the sulfide arsenic ore minerals. Pyrobitumen was a decisive factor in the concentration, transportation, and preservation of gold in the deposit.

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Stochastic-fuzzy multi criteria decision making for robust water resources management   总被引：4，自引：1，他引：3  

Mahdi Zarghami  Ferenc Szidarovszky 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(3):329-339

All realistic Multi Criteria Decision Making (MCDM) problems in water resources management face various kinds of uncertainty. In this study the evaluations of the alternatives with respect to the criteria will be assumed to be stochastic. Fuzzy linguistic quantifiers will be used to obtain the uncertain optimism degree of the Decision Maker (DM). A new approach for stochastic-fuzzy modeling of MCDM problems will be then introduced by merging the stochastic and fuzzy approaches into the Ordered Weighted Averaging (OWA) operator. The results of the new approach, entitled SFOWA, give the expected value and the variance of the combined goodness measure for each alternative, which are essential for robust decision making. In order to combine these two characteristics, a composite goodness measure will be defined. By using this measure the model will give more sensitive decisions to the stakeholders whose optimism degrees are different than that of the decision maker. The methodology will be illustrated by using a water resources management problem in the Central Tisza River in Hungary. Finally, SFOWA will be compared to other methods known from the literature to show its suitability for MCDM problems under uncertainty.  相似文献   

Numerical Modeling of Drainage Schemes in Layered Formations: A Kuwait City Case Study     

Ferenc Székely 《Ground water》1999,37(6):879-883

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The Tolerable Windows Approach: Theoretical and Methodological Foundations   总被引：4，自引：4，他引：0  

Gerhard Petschel-Held  Hans-Joachim Schellnhuber  Thomas Bruckner  Ferenc L. Tóth  Klaus Hasselmann 《Climatic change》1999,41(3-4):303-331

The tolerable windows (TW) approach is presented as a novel scheme for integrated assessment of climate change. The TW approach is based on the specification of a set of guardrails for climate evolution which refer to various climate-related attributes. These constraints, which define what we call tolerable windows, can be purely systemic in nature – like critical thresholds for the North Atlantic Deep Water formation – or of a normative type – like minimum standards for per-capita food production worldwide. Starting from this catalogue of knock-out criteria and using appropriate modeling techniques, those policy strategies which are compatible with all the constraints specified are sought to be identified. In addition to the discussion of the basic elements and the general theory of the TW approach, a modeling exercise is carried out, based on simple models and assumptions adopted from the German Advisory Council on Global Change (WBGU). The analysis shows that if the global mean temperature is restricted to 2°C beyond the preindustrial level, the cumulative emissions of CO2 are asymptotically limited to about 1550 Gt C. Yet the temporal distribution of these emissions is also determined by the climate and socio-economic constraints: using, for example, a maximal tolerable rate of temperature change of 0.2°C/dec and a smoothly varying emissions profile, we obtain the maximal cumulative emissions, amounting to 370 Gt C in 2050 and 585 Gt C in 2100.  相似文献