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1.
Preparation of filter aids based on diatomites   总被引:1,自引:1,他引:1  
Two major deposits of diatomaceous earth (diatomite) in the region of the Balkan Peninsula, the Kolubara basin (Serbia and Montenegro) and the Vesje deposit (Former Yugoslav Republic of Macedonia), were selected for detailed investigation of their possible application in preparation of beer filter aids. Chemical, mineralogical and structural properties of diatomite samples were analyzed with the aim of predicting the filtration efficiency. Results of beer filtering compounds preparation are presented in this paper. The parameters of crushing, drying, calcination and classification are also defined. Beer filtration tests proved diatomites to be satisfactory and not causing any degradation of filtration process or beer quality. Technological flow scheme for obtaining the beer filter aids is proposed in the paper.  相似文献   
2.
On February 20th, 1979, 142 inhabitants of Dieng Plateau (Indonesia) were asphyxiated by poisonous gases during a mild phreatic eruption. From later fields gas collection and analysis, the casualties are considered to be due to CO2 rich volcanic gases.  相似文献   
3.
This paper provides insight into the quality of groundwater used for public water supply on the territory of Kikinda municipality (Vojvodina, Serbia) and main processes which control it. The following parameters were measured: color, turbidity, pH, KMnO4 consumption, TDS, EC, NH4 +, Cl?, NO2 ?, NO3 ?, Fe, Mn, total hardness, Ca2+, Mg2+, SO4 2+, HCO3 ?, K+, Na+, As. The correlations and ratios among parameters that define the chemical composition were determined aiming to identify main processes that control the formation of the chemical composition of the analyzed waters. Groundwater from 11 analyzed sources is Na–HCO3 type. Intense color and elevated organic matter content of these waters originate from humic substances. The importance of organic matter decay is assumed by positive correlation between organic matter content and TDS, HCO3 content. There is no evidence that groundwater chemistry is determined by the depth of captured aquifer interval. The main processes that control the chemistry of all analyzed water are cation exchange and feldspar weathering.  相似文献   
4.
Alexandrium catenella (group IV) and Alexandrium tamarense (group III) (Dinophyceae) are two cryptic invasive phytoplankton species belonging to the A. tamarense species complex. Their worldwide spread is favored by the human activities, transportation and climate change. In order to describe their diversity in the Mediterranean Sea and understand their settlements and maintenances in this area, new microsatellite markers were developed based on Thau lagoon (France) samples of A. catenella and A. tamarense strains. In this study twelve new microsatellite markers are proposed. Five of these microsatellite markers show amplifications on A. tamarense and ten on A. catenella. Three of these 12 microsatellite markers allowed amplifications on both cryptic species. Finally, the haplotypic diversity ranged from 0.000 to 0.791 and 0.000 to 0.942 for A. catenella and A. tamarense respectively.  相似文献   
5.
Water Resources - This paper presents the results of the groundwater quality assessment, on the Serbian Danube, Sava and Morava River water area, for irrigation purposes. The analysis was done at...  相似文献   
6.
This study presents a review of recently recorded instability phenomena on the flysch slopes of Istria, Croatia. The northeastern part of the Istrian Peninsula, the so-called Gray Istria, is built of Paleogene flysch deposits, where instability phenomena are frequent and where a large number of landslides, with significant consequences, have been recorded over the past 35 years. Based on field investigations conducted for the purpose of remedial study design, a database of these landslides was created. An investigation of the documented landslides and their elements found some common features that enabled general conclusions about the conditions and causes of landslide occurrence. In total, 19 documented landslides have been analyzed as individual phenomena, and from the results of these analyses, general conclusions were drawn about sliding conditions and the main triggering factors. Geological conditions and processes on slopes where landslides occurred are shown in detail, and geotechnical properties have been systematically represented. The sliding conditions and dimensions of four recent landslide occurrences, specifically by type, have been described in detail and analyzed.  相似文献   
7.
The geothermal waters of the first and the shallowest groundwater system of the Province of Vojvodina in northern Serbia, south part of the Pannonian Basin, are characterized by elevated temperatures (between 25 and 85 °C) and elevated gas content (above 1 Nm3/m3) with a high methane content (average about 94% of total gases). These methane-containing waters are particularly abundant in the Central part of the province between Danube and Tisa rivers. Dominant ions in these waters are sodium and bicarbonate, but the waters also contain significant amounts of calcium, magnesium, potassium, chloride, and ammonium. Components that are of balneological significance include iodine, bromine, fluorine, strontium, lithium, barium, and metasilicic and metaboric acids. Based on statistical analysis, a strong positive correlation is generally observed in about 9.2% cases. A slightly lower correlation appears in about 42.2%, and negative correlation coefficient appears in about 48.6% cases. The dendrogram of the cluster analysis built on the wells shows three main groups. There is the cluster of (Na+)aq, (Cl)aq and (HCO3)aq. The second aggregation is (NH4+)aq/(NH3)aq. The third group includes (Mg2+)aq, (Ca2+)aq, (Fe3+)aq, (Sr2+)aq, (Pb2+)aq, and (Zn2+)aq.  相似文献   
8.
Desert varnish of pristine sandstone and petroglyph surfaces from Takabart Kabort (Naturalistic Bubaline Art School) and Alamas (Tanzina Art School) can be well classified by their (SiO2+Al2O3):MnO2, Al2O3:SiO2, and P2O5:CaO ratios. Specific ratios are due to the occurrence of clay minerals like illite, kaolinite, smectite, and feldspar, quartz, carbonates like calcite and dolomite, manganese oxyhydroxides, and apatite. Their occurrence corresponds to the local origin and composition of the primary aeolian material.

In general, the analyzed desert varnish shows lamination patterns characterized by alternating MnO2-rich and -poor layers (25 wt% MnO2) at rather constant iron oxyhydroxide content (6 wt% Fe2O3). Varnish on non-engraved surfaces exhibits three MnO2-rich layers, whereas varnish-coated petroglyphs reveal minor lamination patterns corresponding to the dating of petroglyphs by rock art. The older Naturalistic Bubaline Art School petroglyphs (about 6–4 ka BP) and the younger Tazina Art School petroglyphs (about 3.8–3 ka BP) contain only two and one MnO2-rich layer, respectively. It is assumed that the occurrence of such microlaminations is caused by climate changes in North Africa. Three humid periods are discerned from the Terminal Pleistocene to Holocene in the literature. Such periods are suitable to induce manganese accumulation by biotic and abiotic processes. Accordingly, the distinct lamination patterns gained from this study verify the dating of petroglyphs by rock art. From another point of view, classification of the above petroglyphs may be provided by analyses of microlaminations independently on cultural historical aspects.  相似文献   

9.
In order to explain the origin of the Lake Nyos Disaster, a three-dimensional model for carbon dioxide flow has been calculated. The boundary conditions were based on the field observations. Calculations show that CO2 tends to flow down slope by gravity and velocity tends to increase on steep slopes. The results of calculation are in good agreements with the effects observed in the field. The initial velocity of the gas jet should have been 28 m/s, the volume of pure CO2 0.6 km3 and the gas release should occur in a very short time (a few minutes). The gas was released as a jet half way from the center on the south-south west side of the lake.  相似文献   
10.
The paper presents the assessment of emission sources and health risk of 16 PAHs in the city of Novi Sad, Serbia, with developed oil, food, chemical and cement industry. Although the observed region has been previously studied with regard to the occurrence of PAHs in ambient air, the sources of emission and health risk using multivariate statistical methods have never been studied before. The research was conducted during the heating and non-heating periods at three sampling sites located in industrial, residential and high-traffic area. The samples were collected by high-volume air sampler and analysed using the GC/MS system. The data were processed using the positive matrix factorization (PMF) and cluster analysis. To assess the cancer-risk of PAHs, potency equivalency factor approach was used. The results of PMF analysis have indicated that significant sources of PAH emissions are industrial processes and diesel combustion during the non-heating, and coal combustion, heating plants and diesel combustion during the heating season. Cluster analysis of experimental data has confirmed the results obtained using the PMF method. Estimated values of lifetime lung cancer risk were higher than those set by the World Health Organization and US Environmental Protection Agency which indicates that cancer risk due to exposure to PAHs in ambient air exists in both time periods on the territory of Novi Sad.  相似文献   
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