A model of neptune according to the Savić-Kašanin theory

A model of the internal structure of Neptune has been calculated according to the Savi?-Ka?anin theory of behaviour of materials under high pressure.     

High-pressure phase transitions — examples of classical predictability

We present 19 examples of materials whose high pressure phase transition points can be determined within a particular classical theory of dense matter. Theoretical predictions are compared with experimental results, and some possible causes of discrepancies are discussed.     

Evaluation of the Mytilus galloprovincialis Lam. digestive gland metallothionein as a biomarker in a long-term field study: seasonal and spatial variability

A study was made of seasonal and spatial variability of metallothionein (MT) concentrations, determined spectrophotometrically in the soluble fraction of the digestive gland of mussels Mytilus galloprovincialis, collected between 1999 and 2001 from several coastal and estuarine locations along the central Eastern Adriatic coast (Croatia). The seasonal influence on the MT and metal concentrations (higher values in winter-spring season, than in summer-autumn season) is more pronounced than the local site-specific influence. Furthermore, within each season a significant site-specific dependence on the MT and trace metal variations can be detected. An inverse relationship of mussel condition index (CI) and temperature with MT and trace metals levels indicates the influence of food abundance and mussel annual reproductive cycle. Substantially higher concentrations of both MT and Cd were recorded in mussels inhabiting estuarine locations, possibly indicating a markedly higher Cd bioavailability at these locations. The positive correlations obtained between MT and Cd in all seasons except autumn support an argument for application of digestive gland MT as a biomarker of Cd exposure, providing evidence for assessing the most appropriate season for mussel sampling.     

Provenance of Palaeozoic sandstones from the Carnic Alps (Austria): petrographic and geochemical indicators

An integrated approach of petrographic analysis, whole rock geochemistry and microprobe analysis has been applied to obtain information on the geodynamic development and the provenance for Ordovician to Permian siliciclastic successions exposed within the Carnic Alps (Austria). Sandstone detrital mode and geochemical results refine previous geodynamic interpretations. Late Ordovician samples indicate a stable craton and recycled orogenic and, possible, extensional setting. The Early Carboniferous is interpreted to represent a compressional environment, followed by a Late Carboniferous molasse-type foreland basin, and a Permian extensional geodynamic setting. Contrasting geochemical patterns of post-Variscan and Permian sequences suggest a rift setting. Electron microprobe data of detrital white mica also indicate changes in the provenance. Compositional data reflect a shift from low- to medium-grade metamorphic (Ordovician) to high-grade metamorphic (Carboniferous) to low- to medium-grade metamorphic and plutonic source rocks (Permian). Additionally, our data show that various chemical discrimination diagrams do not include all possible ranges of sandstones, and that high contents of detrital mica and ultra-stable heavy minerals may cause misclassification. Consequently, we propose the use of multi-method approach for provenance studies, including the control of geochemical data by modal analysis and heavy mineral investigations.     

Identification of heterogeneous aquifer transmissivity using an AE-based method

Determination of hydraulic head, H, as a function of spatial coordinates and time, in ground water flow is the basis for aquifer management and for prediction of contaminant transport. Several computer codes are available for this purpose. Spatial distribution of the transmissivity, T(x,y), is a required input to these codes. In most aquifers, T varies in an erratic manner, and it can be characterized statistically in terms of a few moments: the expected value, the variance, and the variogram. Knowledge of these moments, combined with a few measurements, permits one to estimate T at any point using geostatistical methods. In a review of transmissivity data from 19 unconsolidated aquifers, Hoeksema and Kitanidis (1985) identified two types of the logtransmissivity Y= ln(T) variations: correlated variations with variance sigma2Yc and correlation scale, I(Y), on the order of kilometers, and uncorrelated variations with variance sigma2Yn. Direct identification of the logtransmissivity variogram, Gamma(Y), from measurements is difficult because T data are generally scarce. However, many head measurements are commonly available. The aim of the paper is to introduce a methodology to identify the transmissivity variogram parameters (sigma2Yc, I(Y), and sigma2Yn) using head data in formations characterized by large logtransmissivity variance. The identification methodology uses a combination of precise numerical simulations (carried out using analytic element method) and a theoretical model. The main objective is to demonstrate the application of the methodology to a regional ground water flow in Eagle Valley basin in west-central Nevada for which abundant transmissivity and head measurements are available.     

Characterization of atmospheric surfactants in the bulk precipitation by electrochemical tools

Characterization of atmospheric surfactants in bulk precipitations was carried out by adsorption study at the mercury electrode/solution interface using phase sensitive AC voltammetry. The structure and permeability of the adsorbed organic films at the mercury electrode was tested using the redox processes of lead and cadmium ions as electrochemical tools. The effects of organic matter from the bulk precipitations (rainwater and melted snow) were compared to those obtained for aqueous solutions of model substances: aromatic hydrocarbon (naphtalene), anionic surfactant (sodium dodecylbenzene sulfonate, NDBS), protein (albumine) and selected model substances suggested to be representative of water soluble organic compounds (WSOC) in atmospheric water (monocarboxylic, dicarboxylic, and polyacidic compounds and levoglucosan). It was found that substances like humic acid and 3-hydroxybutanoic acid may play an important role in atmospheric heterogeneous chemistry because of their surface active potential.     

Gridded Croatian climatology for 1961–1990

In climatology, one of the most important pieces of information about the climate of a place or a region is information about the Climatological Normals (CLINO)—the average values of meteorological elements for a 30-year period. This kind of information usually comes in tables and is available for different observation sites from national meteorological services or from World Meteorological Organisation publications. The key issue, then, becomes how to interpolate these values over the entire area of interest to get reliable and accurate estimates (maps) of climatic elements. Here, the regression kriging framework has been applied for mapping of 20 climatological parameters for the 1961–1990 period for the 56,594 km² of Croatian territory, with a resolution of 1 km. In total, 152 main and climatological and 567 precipitation-measuring stations have been used in the analysis. Extensive pre-processing of metadata on station co-ordinates has been done, as well as completion of missing monthly averages. The final results are 20 climatological maps available in high resolution together with error maps and accuracy assessment measures.     

Improvement of Vertical Diffusion Analytic Schemes Under Stable Atmospheric Conditions

Based on gradient transport theory or K-theory, turbulent transport in the atmosphere has long been parameterized using the eddy diffusivity. Due to its simplicity, this approach has often been applied in many numerical models but rarely tested with observations. Here, the widely used O’Brien cubic polynomial approach has been validated together with an exponential approach against eddy diffusivity profiles determined from measurements and from large-eddy simulation data in stable conditions. Verification is completed by analyzing the variability effects on pollutant concentrations of two different vertical diffusion (K(z)) schemes incorporated in an atmospheric chemical model. It is shown that the analytical, exponential solution agrees better with observations than the O’Brien profile and should be used henceforth in practical applications.     

An analysis of heat waves in Serbia

In this study, heat waves at three meteorological stations in Serbia were analyzed based on the daily maximum temperature during the summer (June, July and August). The warmest summers as regards heat wave duration and severity occurred within the periods 1951–1952, 1987–1998 (especially 1994) and 2000–2007. The longest heat waves were recorded in 1952, lasting 16 days in Smederevska Palanka and 21 days in Ni?, while in 1994 in Belgrade lasting 18 days. The summer of 1994 in Belgrade and Smederevska Palanka, and 2003 in Ni? were characterized with the highest number of consecutive tropical days (21 and 29, respectively).The autoregressive-moving-average models were applied to generate long series of the daily maximum temperature, from which the relative frequencies of heat waves were estimated. The relationships between the longest heat waves, and the circulation conditions were analyzed using the subjective Hess–Brezowsky catalogue of weather types.