Dissolved uranyl complexed species in artificial seawater     

Renata Djogi&#x;  Marko Branica 《Marine Chemistry》1991,36(1-4)

The distribution of dissolved uranyl species was calculated on the basis of the stability constants published elsewhere and compared with the results obtained from the experiments performed in artificial seawater. According to the distributions calculated and electrochemical and spectrophoto-metrical measurements performed in model electrolytes and artificial seawater (pH=8.2) in the presence of sufficient hydrogen peroxide, uranium most probably predominates in the form of a mixed uranyl-dicarbonato-hydrogenperoxo complex. The results obtained could be applied to the natural marine photic zone.The mixed complex has to be taken into account as an additional form of dissolved uranium species influencing their cycle in natural water systems. Recent discovery of the presence of hydrogen peroxide in the surface waters of seas has challenged a long-held notion of the prevalence of uranyl-carbonato complexes in seawater.  相似文献   

Metal pollution assessment of the marine environment by determination of metal-binding proteins in Mytilus sp.     

J Pavi i   M &#x;kreblin  B Raspor  M Branica  M Tu&#x;ek-Z&#x;nidari   I Kregar  P Stegnar 《Marine Chemistry》1987,22(2-4)

Adult mussels (Mytilus galloprovincialis) (shell length 5–7 cm) exposed to elevated concentrations of Cd (0.1–1.3 mg l⁻¹), in a flowing seawater aquarium under laboratory conditions, responded by elevated synthesis of metal-binding proteins in a digestive gland. Response depended on the Cd concentration level as well as on duration of the exposure time. Results obtained show that inducible proteins (isolated by gel-filtration column chromatography and characterized by electrochemical and spectrophotometric methods) should be considered metallothionein-like proteins.The induced metal-binding proteins of mussels in specific organs or tissues are considered to be a potential biological indicator of metal pollution, taking into account specific qualities of the mussel response to different metals. The advantages of the analytical methods applied (gel-chromatography and polarography) and the relevance of the laboratory data when transferred to environmental conditions are discussed. Previously reported results dealing with metal-binding proteins of Mytilus species are also summarized.  相似文献   

Marine sampling by scuba diving. 3. Sampling procedures for measurement of mercury concentrations in estuarine waters and seawater     

Goran Kniewald  &#x;eljko Kwokal  Marko Branica 《Marine Chemistry》1987,22(2-4)

A method for sampling estuarine waters and seawater by scuba diving is described. Samples taken from the Krka River Estuary on the eastern Adriatic coast were analysed for mercury content using cold vapour atomic absorption spectrometry (CVAAS). Mercury levels as low as 1 ng dm⁻³ were determined and these are among the lowest values reported to date. A simple contamination free procedure for the preconditioning of sample containers in the sea was applied. Sampling of water by divers is particularly useful when the intermediate layer in an estuary has to be identified and sampled, as well as for obtaining detailed vertical concentration profiles for mercury and other trace elements.  相似文献   

Petrological, organic geochemical and geochemical characteristics of coal from the Soko mine, Serbia   总被引：1，自引：1，他引：0  

Dragana ivoti&#x;  Herman Wehner  Olga Cvetkovi&#x;  Branimir Jovan i&#x;evi&#x;  Ivan Greti&#x;  Georg Scheeder  Angelika Vidal  Aleksandra &#x;ajnovi&#x;  Marko Ercegovac  Vladimir Simi&#x; 《International Journal of Coal Geology》2008,73(3-4):285-306

A petrological, organic geochemical and geochemical study was performed on coal samples from the Soko Mine, Soko Banja basin, Serbia. Ten coal and two carbonaceous clay samples were collected from fresh, working faces in the underground brown coal mine from different parts of the main coal seam. The Lower Miocene, low-rank coal of the Soko Mine is a typical humic coal with huminite concentrations of up to 76.2 vol.%, liptinite less than 14 vol.% and inertinite less than 11 vol.%. Ulminite is the most abundant maceral with variable amounts of densinite and clay minerals. Sporinite and resinite are the most common macerals of the liptinite group. Inertodetrinite is the most abundant maceral of the inertinite group. The mineral-bituminous groundmass identified in some coal samples, and carbonaceous marly clay, indicate sub-aquatic origin and strong bacterial decomposition. The mean random huminite reflectance (ulminite B) for the main coal seam is 0.40 ± 0.05% Rr, which is typical for an immature to early mature stage of organic matter.The extract yields from the coal of the Soko Banja basin ranges from 9413 to 14,096 ppm, in which alkanes constituted 1.0–20.1%, aromatics 1.3–14.7%, asphaltenes 28.1–76.2% and resins 20.2–43.5%. The saturated hydrocarbon fractions included n-C₁₅ to n-C₃₂, with an odd carbon number that predominate in almost all the samples. The contents of n-C₂₇ and n-C₂₉ alkanes are extremely high in some samples, as a contribution of epicuticular waxes from higher plants. Acyclic isoprenoid hydrocarbons are minor constituents in the aliphatic fraction, and the pristane/phytane (Pr/Ph) ratio varies between 0.56 and 3.13, which implies anaerobic to oxic conditions during sedimentation. The most abundant diterpanes were abietane, dehydroabietane and 16α(H)-phyllocladane. In samples from the upper part of the coal seam, diterpanes are the dominant constituents of the alkane fraction. Polycyclic alkanes of the triterpane type are important constituents of alkane fractions. The occurrence of ββ- and αβ-type hopanes from C₂₇ to C₃₁, but without C₂₈, is typical for the Soko Banja coals.The major and trace elements in the coal were analysed using X-ray fluorescence (XRF), and inductively coupled plasma-mass spectrometry (ICP-MS). In comparison with world lignites, using the geometric mean value, the coal from the Soko Banja Basin has a high content of strontium (306.953 mg/kg). Higher values than the world lignites were obtained for Mo (3.614 mg/kg), Ni (8.119 mg/kg), Se (0.884 mg/kg), U (2.642 mg/kg) and W (0.148 mg/kg). Correlation analysis shows inorganic affinity for almost all the major and trace elements, except for S, which has an organic affinity.  相似文献   

Application of run-off model as a contribution to the torrential flood risk management in Topčiderska Reka watershed,Serbia     

Ana M. Petrović  Jelena Kovačević-Majkić  Marko V. Milošević 《Natural Hazards》2016,82(3):1743-1753

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Seismic response analysis using characteristic ground motion records for risk‐based decision‐making (3R method)          下载免费PDF全文

Matjaž Dolšek  Marko Brozovič 《地震工程与结构动力学》2016,45(3):401-420

The concept of intensity‐based assessment for risk‐based decision‐making is introduced. It is realized by means of the so‐called 3R method (response analysis, record selection and risk‐based decision‐making), which can be used to check the adequacy of design of a new building or of the strengthening of an existing building by performing conventional pushover analysis and dynamic analysis for only a few ground motions, which are termed characteristic ground motions. Because the objective of the method is not a precise assessment of the seismic risk, a simple decision model for risk acceptability can be introduced. The engineer can decide that the reliability of a no‐collapse requirement is sufficient when collapse is observed in the case of less than half of, for example, seven characteristic ground motions. From the theoretical point of view, it is shown that the accuracy of the method is acceptable if the non‐linear response history analyses are performed at a low percentile of limit‐state intensity, which is also proven by means of several examples of multi‐storey reinforced concrete frame buildings. The 3R method represents a compromise between the exclusive use of either pushover analysis or dynamic analysis and can be easily introduced into building codes provided that its applicability is further investigated (e.g. asymmetric structures and other performance objectives) and that the procedure for the selection of characteristic ground motions is automated and readily available to engineers (www.smartengineering.si).  相似文献   

Land degradation analysis of mine-impacted zone of Kolubara in Serbia     

Miško Milanović  Milisav Tomić  Veljko Perović  Milan Radovanović  Saumitra Mukherjee  Darko Jakšić  Marko Petrović  Ana Radovanović 《Environmental Earth Sciences》2017,76(16):580

This paper presents the effect of land-use changes on land degradation by utilization of remote sensing methods and the Gavrilovi? erosion potential method, due to surface mining activities in the period 2001–2011. Studied area includes the zone of influence of the Rudarski basen Kolubara, which covers the exploitation area of the Kolubara coal basin in the Republic of Serbia. The analysis is based on the processing of Landsat 5 satellite images from 2001 and 2011. In the analysis of satellite images, the supervised classification method was used. The results suggest that the observed spatial–temporal area is exposed to erosion as a result of land-use changes. Preliminary conclusion is that the dominant anthropogenic factor, responsible for changes in land use, is pronounced through the mining activity, industrialization, construction as well as agricultural activities. Very small changes in land use that occurred in the period 2001–2010 have led to relatively small amount of change from the aspect of land degradation. Also, due to the planned exploitation of the mine which included into account the sustainability of ecosystems, primarily through appropriate conservation measures, RB Kolubara is not in danger of a possible erosion processes that could undermine the stability of the basin.  相似文献   

ASSESSMENT OF MACCORMACK SCHEME IN UNSTEADY SEDIMENT LADEN FLOW COMPUTATION     

Shaohua Marko HSU  Tzu Ming LIU  and Chih Kang WEN 《国际泥沙研究》1999,(1)

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Regional Flood Frequency Analysis Based on L-Moment Approach (Case Study Tisza River Basin)     

Igor Leščešen  Urošev  Marko  Dolinaj  Dragan  Pantelić  Milana  Telbisz  Tamás  Varga  György  Savić  Stevan  Milošević  Dragan 《Water Resources》2019,46(6):853-860

Water Resources - Floods are one of the most common natural hazards and as such, they are causing a great loss of human life as well as great economic damages. Flood frequency analysis (FFA) is...  相似文献   

Coupling of GPS/GNSS and radar interferometric data for a 3D surface displacement monitoring of landslides   总被引：2，自引：1，他引：1  

Marko Komac  Rachel Holley  Pooja Mahapatra  Hans van der Marel  Miloš Bavec 《Landslides》2015,12(2):241-257

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