Metal concentration and particle size distribution of stream and river water polluted from copper rolling mill industry

Concentrations of heavy metals, pH, and particle size distribution parameters were measured in Dragica stream and Djetinja River water receiving wastewaters from copper rolling mill industry, Sevojno. The concentrations of copper, zinc, lead, and mercury were determined for water samples collected in summer 2009. It was found that Copper Rolling Mill Sevojno was the significant source of water pollution with copper and zinc. Considering that copper rolling mill industry, one of the larger emitters of sulfur dioxide, pollutes the area, the water pH was surprisingly alkaline. The particle size analysis results showed that particles from oil-in-water emulsion evidently got into stream water in spite of the purification devices used. In order to assess the possible relations between the measured parameters, a correlation analysis was performed. The correlation analysis showed a significant positive correlation between the total metal concentrations of copper and zinc, as well as between particle size distribution parameters and the concentration of lead and copper.     

On the supernova remnants with flat radio spectra

A considerable fraction of Galactic supernova remnants (SNRs) characterize flat spectral indices (α<0.5). There are several explanations of the flat radio spectra of SNRs in the present literature. The most of models involve a significant contribution of the second-order Fermi mechanism but some of them also discuss high compressions (>4), contribution of secondary electrons left over from the decay of charged pions, as well as the possibility of thermal contamination. In the case of expansion in high density environment, intrinsic thermal bremsstrahlung could theoretically shape the radio spectrum of an SNR and also account for observable curved—“concave up” radio spectra of some Galactic SNRs. This model could also shed a light on the question of flat spectral indices determined in some Galactic SNRs. On the other hand, present knowledge of the radio continuum spectra (integrated flux densities at different frequencies) of SNRs prevent definite conclusions about the significance of proposed models so the question on flat spectral indices still remains open. New observations, especially at high radio continuum frequencies, are expected to solve these questions in the near future. Finally, as there is a significant connection between the majority of Galactic SNRs with flat integrated radio spectrum and their detection in γ-rays as well as detection of radiative recombination continua in their X-ray spectra, the analysis of high energy properties of these SNRs is very important.     

Aridity in Vojvodina, Serbia

For investigating aridity in Vojvodina, two parameters were used: the De Martonne aridity index and the Pinna combinative index. These indices were chosen as the most suitable for the analysis of climate in Vojvodina (a region in northern part of Serbia). Also, these indices were calculated from data obtained from 10 meteorological stations for the period from 1949 to 2006. The spatial distribution of the annual and seasonal De Martonne and the Pinna combinative indices as well as the mean monthly values of the De Martonne index and aridity trends of these indices are presented. There were two, four, and five types of climate on a yearly, seasonal, and monthly basis in Vojvodina, according to the De Martonne climate classification which consists of a total of seven types. In addition, semi-humid and humid climate types were represented in the region, on a yearly basis. The winter season was dominated by wetter types of climate, while the summer season was characterized by drier ones. During the spring and autumn seasons, there were types of climate which range between both aforementioned types. Two out of three climate types, which can be identified using the Pinna combinative index, were registered in Vojvodina region. The most dominant climate type was the semidry Mediterranean with formal Mediterranean vegetation, while the humid type was only identified in one small part of southwestern Vojvodina. The calculated values of both aridity indices showed that there were no annual trends. Therefore, it can be considered that there were no recent aridity changes during the observed period. For paleoclimate, the general story is more complex. The lack of aridity trends in the recent period from 1949 to 2006 supports the fact that Vojvodina has very well preserved loess–palaeosol sequences from the Middle and Late Pleistocene, which indicates that crucial point for their preservation was caused by the weak aridity variability in the region.     

Enabling geosimulations for global scale: Spherical geographic automata

Several complex dynamic spatial systems are operating on the global scale. Their representation with existing geosimulation models is limited to planar level and do not consider the curvature of the Earth's surface. Thus, the objective of this study is to propose and develop a spherical geographic automata (SGA) modeling approach to represent and simulate dynamic spatial processes at the global level. The proposed SGA model is implemented for three case studies including simulations of: (1) Game of Life as population dynamics; (2) urban land-use growth; and (3) deforestation all operating on the spherical Earth's surface. Simulation results indicate that the proposed SGA modeling approach can represent spatial processes such as expansion and shrinkage dynamics on the Earth's surface. The proposed approach has the potential to be adopted to represent different complex systems such as ecological, epidemiological, socioeconomic, and Earth systems processes to support environmental management and policymaking at the global level.     

Towards a new methodological framework for the delimitation of rural and urban areas: a case study of Serbia

Abstract: Identification of urban and rural areas has been a widely present topic in the past decades, both in scientific research and in the policy and practice of spatial/regional development and territorial governance. The internationally accepted OECD definition does not produce appropriate results that are able to include the multidimensionality of these territories. In this context, the aim of this paper is the analysis and selection of relevant criteria and indicators of urbanity/rurality that may be significant for the establishment of a methodological framework for identifying urban and rural areas in Serbia. Multivariate analysis (PCA, FA and CA) was used to group local self-government units (LSGU) in Serbia that share similar characteristics. The research resulted in five types of areas which indicate that rural and urban areas in Serbia are very diverse in terms of physiogeographical, socio-economic and functional characteristics. The results of this paper offer a more detailed analysis based on scientifically and empirically selected indicators and can be applied in the practice of spatial and urban planning, and in the adaptation of strategic development documents at the regional or national level.     

Consequences of anthropogenic activity for two remote alpine lakes in NW Slovenia as tracked by sediment geochemistry

Several geological and geochemical parameters were determined in the sediments of the 5th (5 J) and 6th (6 J) Triglav Lakes, Julian Alps (NW Slovenia), in order to study the impact of natural catchment characteristics and anthropogenic activity. Fish were introduced into both lakes in 1991 and a mountain hut lies on the shore of 5 J. Sedimentary grain size (GS) was distinctly coarser in 5 J than 6 J, with arithmetic means ranging between 46 and 60 and 23–36 μm, respectively. In contrast, the mineralogical composition of the two sediments was similar. Calcite predominated strongly, comprising more than 77 % of total minerals, while dolomite and quartz were rare. Organic carbon (OC) and total nitrogen (TN) concentrations were highest in surficial sediments, with levels of 14.4 and 1.8 %, and 19.3 and 2.4 % observed in 5 J and 6 J, respectively. C/N ratios (atomic) were lowest in the same surface sediments, with the two lakes characterized by similar values (9.6 vs. 9.4, respectively), suggesting a predominance of autochthonous organic matter (OM) in both lakes. Contemporary δ¹³C values were lower in 5 J (?21.0 ‰) than 6 J (?18.5 ‰) sediments. Considerable changes in these four parameters were observed in recently deposited material, reflecting a shift in the trophic status of both lakes that was likely induced by the introduction of fish. In addition, the smaller and shallower 6 J seemed to respond to changes faster than the larger and deeper 5 J, indicating the higher sensitivity of the former. δ¹⁵N values in surface sediments of 5 J and 6 J were ?2.9 and ?4.4 ‰, respectively, with levels increasing gradually with depth to approximately +1.0 ‰ in deeper sediments. The observed changes could most likely be attributed to the atmospheric deposition of reactive nitrogen. The mountain hut has seemingly not had a significant enough impact on the lakes to be recorded in their sediments.     

Strontium isotope identification of water mixing and recharge sources in a river system (Oder River,central Europe): A quantitative approach

This study uses Sr isotope composition (⁸⁷Sr/⁸⁶Sr) and Sr content of waters of the Oder, one of the largest rivers in central Europe, to fingerprint natural and anthropogenic contributions to its Sr budget and to evaluate water mixing processes in its hydrological system. It also demonstrates a simple method of quantifying natural and anthropogenic Sr inputs in the watershed. The method has potential for environmental and archaeological research because past Sr geochemistry of river water can easily be reconstructed. For the first time, a catchment‐scale impact of anthropogenic sources on the Sr budget of a middle‐size river is shown in a quantitative way. The water of the Oder is characterized by a relatively uniform Sr isotope composition, from 0.7100 to 0.7108, contrasting with strong variations in Sr concentration, from 0.25 to 1.27 mg/L. There is a general seasonal trend in variability, with waters becoming more radiogenic and dilute with respect to the Sr in the spring time. This Sr systematics differs significantly from the Sr budgets of the majority of the Oder tributaries that exhibit more radiogenic composition and systematically lower Sr concentrations. A mixing scenario in the Oder involves Sr contribution from four principal water sources: (a) shallow ground waters with Sr derived from near‐surface weathering of silicates, (b) moderately radiogenic mine waters from the Upper Silesian Coal Basin, (c) unradiogenic mine waters from the Permian sequence of the copper district, and (d) unradiogenic ground waters from shallow‐seated Palaeogene, Neogene, and Mesozoic aquifers. The Sr budget of the Oder is primarily controlled by inputs of dissolved Sr from anthropogenic sources, which overprint the natural background, controlled by geology. Thus, about 47.5% of Sr originates from agriculture, industrial, and municipal additions, 31.5% from mine water inputs, and only 21% from natural sources, that is, rock weathering and atmospheric precipitation. Reconstruction of the past Sr chemistry of the Oder reveals that its present‐day Sr isotope composition is temporary and significantly different from that of the preindustrial times.     

Post‐earthquake bridge repair cost and repair time estimation methodology

While structural engineers have traditionally focused on individual components (bridges, for example) of transportation networks for design, retrofit, and analysis, it has become increasingly apparent that the economic costs to society after extreme earthquake events are caused at least as much from indirect costs as direct costs due to individual structures. This paper describes an improved methodology for developing probabilistic estimates of repair costs and repair times that can be used for evaluating the performance of new bridge design options and existing bridges in preparation for the next major earthquake. The proposed approach in this paper is an improvement on previous bridge loss modeling studies—it is based on the local linearization of the dependence between repair quantities and damage states so that the resulting model follows a linear relationship between damage states and repair points. The methodology uses the concept of performance groups (PGs) that account for damage and repair of individual bridge components and subassemblies. The method is validated using two simple examples that compare the proposed method to simulation and previous methods based on loss models using a power–law relationship between repair quantities and damage. In addition, an illustration of the method is provided for a complete study on the performance of a common five‐span overpass bridge structure in California. Intensity‐dependent repair cost ratios (RCRs) and repair times are calculated using the proposed approach, as well as plots that show the disaggregation of repair cost by repair quantity and by PG. This provides the decision maker with a higher fidelity of data when evaluating the contribution of different bridge components to the performance of the bridge system, where performance is evaluated in terms of repair costs and repair times rather than traditional engineering quantities such as displacements and stresses. Copyright © 2009 John Wiley & Sons, Ltd.     

Application of Gravity Gradients in the Process of GOCE Orbit Determination

The possibility of improving the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) mission satellite orbit using gravity gradient observations was investigated. The orbit improvement is performed by a dedicated software package, called the Orbital Computation System (OCS), which is based on the classical least squares method. The corrections to the initial satellite state vector components are estimated in an iterative process, using dynamic models describing gravitational perturbations. An important component implemented in the OCS package is the 8th order Cowell numerical integration procedure, which directly generates the satellite orbit. Taking into account the real and simulated GOCE gravity gradients, different variants of the solution of the orbit improvement process were obtained. The improved orbits were compared to the GOCE reference orbits (Precise Science Orbits for the GOCE satellite provided by the European Space Agency) using the root mean squares (RMS) of the differences between the satellite positions in these orbits. The comparison between the improved orbits and the reference orbits was performed with respect to the inertial reference frame (IRF) at J2000.0 epoch. The RMS values for the solutions based on the real gravity gradient measurements are at a level of hundreds of kilometers and more. This means that orbit improvement using the real gravity gradients is ineffective. However, all solutions using simulated gravity gradients have RMS values below the threshold determined by the RMS values for the computed orbits (without the improvement). The most promising results were achieved when short orbital arcs with lengths up to tens of minutes were improved. For these short arcs, the RMS values reach the level of centimeters, which is close to the accuracy of the Precise Science Orbit for the GOCE satellite. Additional research has provided requirements for efficient orbit improvement in terms of the accuracy and spectral content of the measured gravity gradients.     

Effectiveness of tune mass damper in the reduction of the seismic response of the structure

A shaking table testing of a 16.6 t five storey steel frame structure with and tuned mass damper (TMD) named as Tuned Mass Control System (TMCS) installed at the top has been carried out in the Dynamic Testing Laboratory at the Institute of Earthquake Engineering and Engineering Seismology (IZIIS) in Skopje, Republic of Macedonia. For estimation of the effectiveness of Tuned Mass Control System (TMCS) large number of shaking table experiments have been performed. Simulating different earthquake time histories on the model structure with and without TMCS it has been demonstrated that this system is capable to reduce the responses in order from 10% to more than 50% depending on the frequency content of the seismic input and the corresponding sensitivity of the structure. Given a high quality analytical model of a structure and a dynamic absorber, a series of variant analyses have been performed within the study to investigate the effect of the individual parameters and evaluate the efficiency of the dynamic absorber. The analyses have been performed to define the effect of the location of the absorber, also, upon the dynamic behaviour of the structure in the case the absorber is installed at the different level (storey) of the structure. Comparative analysis of the structure with TMCS having optimally tuned its mechanical properties versus structure that has TMCS having the same mechanical properties as tested specimen showed that the TMCS additionally improves the structural behaviour, depending on frequency content of earthquake excitation.