The behavior of arsenic and antimony at Pezinok mining site,southwestern part of the Slovak Republic     

Renata Flakova  Zlatica Zenisova  Ondra Sracek  David Krcmar  Ivana Ondrejkova  Martin Chovan  Bronislava Lalinská  Miriam Fendekova 《Environmental Earth Sciences》2012,66(4):1043-1057

Arsenic and antimony contamination is found at the Pezinok mining site in the southwest of the Slovak Republic. Investigation of this site included sampling and analysis of water, mineralogical analyses, sequential extraction, in addition to flow and geochemical modeling. The highest dissolved arsenic concentrations correspond to mine tailings (up to 90,000 μg/L) and the arsenic is present predominately as As(V). The primary source of the arsenic is the dissolution of arsenopyrite. Concentration of antimony reaches 7,500 μg/L and its primary source is the dissolution of stibnite. Pore water in mine tailings is well-buffered by the dissolution of carbonates (pH values between 6.6 and 7.0) and arsenopyrite grains are surrounded by reaction rims composed of ferric iron minerals. Based on sequential extraction results, most solid phase arsenic is in the reducible fraction (i.e. ferric oxyhydroxides), sulfidic fraction, and residual fraction. Distribution of antimony in the solid phase is similar, but contents are lower. The principal attenuation mechanism for As(V) is adsorption to ferric oxide and hydroxides, but the adsorption seems to be limited by the competition with Sb(V) produced by the oxidation of stibnite for adsorption sites. Water in mine tailings is at equilibrium with gypsum and calcite, but far from equilibrium with any arsenic and antimony minerals. The concentrations of arsenic and antimony in the surrounding aquifer are much lower, with maximum values of 215 and 426 μg/L, respectively. Arsenic and antimony are transported by ground water flow towards the Blatina Creek, but their loading from ground water to the creek is much lower compared with the input from the mine adits. In the Blatina Creek, arsenic and antimony are attenuated by dilution and by adsorption on ferric iron minerals in stream sediments with resulting respective concentrations of 93 and 45 μg/L at the site boundary south of mine tailing ponds.  相似文献   

Requirements Elicitation for Geo-information Solutions     

Claudia Robbi Sluter  Corné P. J. M. van Elzakker  Ivana Ivánová 《The Cartographic journal》2017,54(1):77-90

Geo-information solutions can achieve a higher level of quality if they are developed in accordance with a user-centred design that requires definition of the user requirements in the first step of solution construction. We treat a geo-information solution as a system designed to support human-based activities in a specific context through which solutions to contextual problems can be achieved via geographic knowledge. Geographic knowledge is a result of geo-data exploration, analysis, interpretation and dissemination with a given geo-information system. Taking the characteristics of geo-information systems into account, existing methods and techniques of requirements engineering may be applied for the design and implementation of geo-information solutions. Based on these considerations, here we present a generic framework that can aid geo-information experts, geo-informaticians and cartographers in the design and construction of more efficient, effective and satisfactory solutions.  相似文献   

Geochemical history of a Lower Miocene lake,the Cypris Formation,Sokolov Basin,Czech Republic     

Bohdan Kříbek  Ilja Knésl  Petr Rojík  Ivana Sýkorová  Karel Martínek 《Journal of Paleolimnology》2017,58(2):169-190

The intracontinental Lower Miocene Cypris paleo-lake originated during progressive subsidence in the Sokolov Basin, part of the Cenozoic Oh?e Rift, after the deposition of coal seams. The Cypris Fm. consists almost entirely of lacustrine clays with variable mineral composition and organic matter, where this succession is 70–120 m thick. The main objective of this study was to interpret the geochemical history of the Lower Miocene Cypris Fm. using high-resolution, down-core geochemical records and study of the organic matter. This work revealed that the lower part of the lacustrine sediment sequence was deposited in a freshwater lake, in an open hydrological system. An increase in the K/Zr and K/Ti ratios towards the upper part of the Cypris Fm. indicates a gradual increase in the pelitic fraction of the local sediments and/or a decline in input of volcanic material. Simultaneously, increasing Ca/K and Sr/K ratios indicate the precipitation of carbonates, predominantly dolomite and siderite. In the upper part of the Cypris Fm., there is a significant increase in Na/K, Na/Zr, and Na/Ti ratios, suggesting increasing salinity (alkalinity) of the paleoenvironment in a closed hydrological system. Reaction between the Na-rich water and clastic components of the sediment in an alkaline medium gave rise to the formation of zeolites, mixed-layer clay minerals and smectite. Abundant remains of aquatic organisms, especially algae, increased with greater salinity in the upper part of the Cypris Fm. This is reflected in the greater hydrogen index (HI_{Rock Eval}), and the growing proportion of liptinite group macerals of aquatic origin in the bulk organic matter. During the entire history of sedimentation in the Miocene lake, repetitive changes in the sediment geochemistry occurred at both micro- and macroscales, and fluctuations of K/Ti, K/Zr, and Sr/Ca ratios over meters to tens of meters are observed. These changes probably reflect either long-term climate fluctuations during the Lower Miocene or oscillations caused by changes in the rate of subsidence of the basin floor. Variations in the elemental composition of sediments can be used to correlate individual boreholes across the entire sedimentary basin.  相似文献   

Erratum to: On the Measurement of Turbulence Over Complex Mountainous Terrain     

Ivana Stiperski  Mathias W. Rotach 《Boundary-Layer Meteorology》2016,161(1):223-223

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Circulation weather types and their influence on precipitation in Serbia     

Suzana Putniković  Ivana Tošić  Vladimir Đurđević 《Meteorology and Atmospheric Physics》2016,128(5):649-662

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Understanding the influence of climate elements on traffic: the wind impact approach     

Sentić  Ivana  Đorđević  Tijana  Đorđević  Jasmina  Ljubojević  Mirjana  Čukanović  Jelena 《Theoretical and Applied Climatology》2022,149(1-2):661-681

Theoretical and Applied Climatology - Due to intense highway congestion in Europe, increased percentage of highway accidents, as well as mortality rate, safety is an imperative in highway planning...  相似文献   

Adriatic seiche decay and energy loss to the Mediterranean     

Ivana Cerove?ki  Mirko Orli?  Myrl C. Hendershott 《Deep Sea Research Part I: Oceanographic Research Papers》1997,44(12):2007-2029

A salient feature of sea level records from the Adriatic Sea is the frequent occurrence of energetic seiches of period about 21 h. Once excited by a sudden wind event, such seiches often persist for days. They lose energy either to friction within the Adriatic, or by radiation through Otranto Strait into the Mediterranean.The free decay time of the dominant (lowest mode) seiche was determined from envelopes of handpassed sea level residuals from three locations (Bakar, Split and Dubrovnik) along the Croatian coast during twelve seiche episodes between 1963 and 1986 by taking into consideration only time intervals when the envelopes decreased exponentially in time, when the modelled effects of along-basin winds were smaller than the error of estimation of decay time from the envelopes and when across-basin winds were small. The free decay time thus obtained was 3.2±0.5 d. This value is consonant with the observed width of the spectral peak.The decay caused by both bottom friction and radiation was included in a one dimensional variable cross section shallow water model of the Adriatic. Bottom friction is parameterized by the coefficient k appearing in the linearized bottom stress term _ρ0u (where u is the along-basin velocity and ρ₀ the fluid density). The coefficient k is constrained by values obtained from linearization of the quadratic bottom stress law using estimates of near bottom currents associated with the seiche, with wind driven currents, with tides and with wind waves. Radiation is parameterized by the coefficient f appearing in the open strait boundary condition ζ =auh/c (where ζ is sea level, h is depth and c is phase speed). This parameterization of radiation provides results comparable to allowing the Adriatic to radiate into an unbounded half plane ocean. Repeated runs of the model delineate the dependence of model free seiche decay time on k and a, and these plus the estimates of k allow estimation of a.The principle conclusions of this work are as follows.

1. (1) Exponential decay of seiche amplitude with time does not necessarily guarantee that the observed decay is free of wind influence.

2. (2) Winds blowing across the Adriatic may be of comparable importance to winds blowing along the Adriatic in influencing apparent decay of seiches; across-basin winds are probably coupled to the longitudinal seiche on account of the strong along-basin variability of across-basin winds forced by Croatian coastal orography.

3. (3) The free decay time of the 21.2 h Adriatic seiche is 3.2±0.5 d.

4. (4) A one dimensional shallow water model of the seiche damped by bottom stress represented by Godin's (1988) approximation to the quadratic bottom friction law ρ₀C_Du|u| using the commonly accepted drag coefficient C_D = 0.0015 and quantitative estimates of bottom currents associated with wind driven currents, tides and wind waves, as well as with the seiche itself with no radiation gives a damping time of 9.46 d; radiation sufficient to give the observed damping time must then account for 66% of the energy loss per period. But independent estimates of bottom friction for Adriatic wind driven currents and inertial oscillations, as well as comparisons between quadratic law bottom stress and directly measured bottom stress, all suggest that the quadratic law with C_D=0.0015 substantially underestimates the bottom stress. Based on these studies, a more appropriate value of the drag coefficient is at least C_D=0. In this case, bottom friction with no radiation leads to a damping time of 4.73 d, radiation sufficient to give the observed damping time then accounts for 32% of the energy loss per period.

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Paleoenvironmental reconstruction of Holocene coastal depositsfrom the Southeastern Buenos Aires Province, Argentina     

Marcela Espinosa  Claudio De Francesco  Federico Isla 《Journal of Paleolimnology》2003,29(1):49-60

An estuarine sequence outcropping at La Ballenera Creek (BuenosAires Province), dated between 6,800 and 4,100 ¹⁴C years BP, wasinvestigated for diatoms and molluscs. The sea level history along the BuenosAires coastline has been reconstructed from discrete beach ridge sequencesalong low-lying plains. The La Ballenera profile is located on a cliffcoast where a sequence recorded environmental changes. Fifty-eightdiatom species were grouped based on their salinity and life formcharacteristics. Cluster analysis allowed the division of the sequence intothree diatom zones. Mollusc tolerances were also used to discern theenvironmental changes induced by sea-level fluctuations. The base of thesequence recorded the initiation of the marine influence about6,790–6,200 years ago. Diatom assemblages consist ofbrackish-freshwater tychoplankton accompanied by brackish benthicdiatoms. Among the molluscs, the freshwater-brackish species Heleobiaparchappii dominates. Between 6,200 and ca. 4,800 ¹⁴C years BP, anestuarine lagoon environment is indicated by benthic and epiphyticmarine-brackish diatoms, as well as by the estuarine snail Heleobiaaustralis. After 4,800 ¹⁴C years BP, the diatom assemblages and therelative abundance of freshwater molluscs indicate a marshy environment withlower salinity content. The La Ballenera records the salinity changes thataffect an estuary that infilled during the 2,700 years after the maximum sealevel reached in mid-latitudes of South America.  相似文献   

Seyfert Galaxies: A Perspective with the Infrared Space Observatory (ISO)     

A.M. Pérez García  J.M. Rodríguez Espinosa 《Astrophysics and Space Science》1998,263(1-4):103-106

We present data from the Infrared Space Observatory (ISO) of a complete set of Seyfert galaxies (Seyfert 1 and Seyfert 2) in a wavelength range seldom explored so far. These data allow a detailed study of the far IR Spectral Energy Distribution of these sources. A Bayesian inversion method has been used to invert the Spectral energy Distribution (SED) of these sources yielding two fundamental results, namely that the far IR SED of Seyfert Galaxies can be explained solely through thermal reradiation of high energy photons by dust. And, that this thermal emission is made up of two or three independent components. Comparisons between the parameters obtained from the analysis of the IR SEDs and the emission in other wavelengths ranges (radio and X-rays) show that the host galaxies are key elements in the understanding of the IR emission of Seyferts. Besides, the nuclear properties seem to be adequately explained with the Unified Models of AGN, that state that the differences seen between the broad (Seyfert 1) and narrow (Seyfert 2) line objects are due to geometrical orientation effects. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Influence of atmospheric pressure variations on measurements made with Sharpe and Worden gravimeters     

Ladislav Gargalovič  Ludmila Kubáčková  Ivana Jakubcová  Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1978,22(1):93-98

Summary The paper deals with the influence of the atmospheric pressure variations on Sharpe gravimeters CG 2 No. 226 and 280 and on the Worden gravimeter No. 978, equipped with a thermostat.Dedicated to RNDr. Jan Pícha, CSc., on his 60th Birthday  相似文献