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The village of Dubravica is partially located over the western lignite deposits of the Kostolac basin. The examination of the dry residue obtained from drinking water from two individual wells by X-ray diffraction analysis, based on a typical peak, showed the presence of uranium in drinking water. The indirect method by Rajković and associates showed that, in sample I, the concentration of uranium in drinking water was 85.5 percent higher (3.71 mg/L) and that the concentration of uranium in sample II was only 22 percent lower (1.56 mg/L) than the Maximum Allowable Concentration (MAC) values required by the Regulations (2 mg/L). Analysis of the result of the introduction of uranium in the human body has shown that this way brings 0.84 to 2 mg of uranium in the human organism per annum or 0.09 to 0.22 mg of uranium is deposited annually in the kidney. Assessment of the potential health risk due to the presence of uranium in drinking water indicated that the population using drinking water from wells will be threatened by uranium in a short time interval. Regarding the long-term risk, the calculation has indicated that in the first sample of drinking water, about 25 inhabitants, and in the case of the second sample of drinking water, 10 inhabitants out of 1000 inhabitants are endangered. As the kidney is the organ in which uranium is deposited (accumulated) to the greatest extent, its presence causes weakening and failure of kidney function, which can destroy 75 percent of kidney function until the manifestation of the first clinical symptoms. This phenomenon is observed among the population along the rivers the Kolubara, the Drina, the Sava and the Morava and is called endemic nephropathy. The elements found in trace amounts (Pb, Cd, Si), live agents (bacteria and viruses), fungal plant toxins, genetic factors and immune mechanism can be listed as possible causes. However, uranium in drinking water has not been listed so far. The tests performed in this study clearly show the role of uranium in the epidemic, endemic nephropathy, which is growing and which is not at the acute phase of the disease but has already progressed to renal failure and end-stage kidney disease. Official data on the rise of endemic nephropathy and diabetes and increasing their share in diseases, as well as overall mortality rates, which amount to 18.19%, clearly indicate that the role of uranium in the Braničevo district environment should not be ignored. Since there are settlements on the terrain to be investigated, uranium and its migration through the environment must be monitored as all conditions for its migration are unfortunately favourable.

The paper presents the results of testing the effect of pyrophyllite shale (pyrophyllite) on the quality of maize plant silage, primarily on the production of organic acids, pH value, quality assessment and microbiological safety. The ensiling was done in plastic containers which allowed the storage of 10 kg of chopped green mass. Tested pyrophyllite doses were: 0% in the control treatment (I), 0.5 and 1.0% in experimental treatments (II and III, respectively). Granulated pyrophyllite (100 µm), originating from Parsovići, Konjic site, AD Harbi Ltd., Sarajevo, Bosnia and Herzegovina, was manually incorporated. The chopped green mass of the maize plant came from FAO 600 hybrids. The green mass containing 37.17% of dry matter (final waxy ripening phase) was compressed in the same manner in all three treatments during the filling of the vessels. The containers were then covered with nylon foil (0.2 mm) above which a layer of fine sand (approx. 5 cm) was placed in toward the silage protection from air passage. The silages were opened after 7 weeks and organoleptic, chemical and microbiological analyses were performed. The organoleptic properties of silages (colour and odour) were better in silages containing 0.5 and 1.0% pyrophyllite. The silage temperature at the moment of opening of the containers was lower in the treatments with 0.5 and 1.0% added pyrophyllite (13.7 and 13.2 °C, respectively) while in the control treatment it was 14.6 °C. The addition of pyrophyllite to silage affected the production of volatile fatty acids (p ≤ 0.05). The highest amount of lactic acid was found in the silage sample without the addition of pyrophyllite, and acetic acid in the silage treated with 0.5 and 1.0% of pyrophyllite. The lowest amount of butyric acid was determined in the silage with the addition of 1% pyrophyllite. Based on the content and interrelationship of lactic, acetic and butyric acid, as well as the pH values, all three silages were rated as the highest (I) class. The number of aerobic mesophilic bacteria, as well as the number of yeasts, was lower in the silages with the addition of 0.5 and 1.0% pyrophyllite. In future, particular attention should be paid on the possibility of pyrophyllite enrichment (e.g. with nitrogen) and more appropriate physical formulation (e.g. granules) that would allow more efficient practical application.

This study aims at analysing physical, chemical and microbiological properties, and content of macro- and microelements in the water from the Požarevac city public water supply system. Analysis shows an increased content of Ca in drinking water, as a result of the position of Požarevac on the sediments of river terrace of accumulative character of t1 type, predominantly consisting of quartzite. The water from the public water supply is alkaline ('calcic', 'bicarbonate water') and very hard, due to the increased Ca content. Beside Ca, potassium and aluminium exceed the maximum contaminant level, while Pb and Cd are at the very limit. Calculated data show that there are no short-term health risks regarding elements exceeding allowed concentrations found in the public water supply system. Data analysis regarding long-term health risks shows that Cd present in drinking water poses the only relevant threat to human health. Cancer risk is present in 202 out of 1000 inhabitants using this water.

In order to verify the content of macro- and microelements in drinking water in the village of Dubravica in the Branicevo district, which has no centralized water supply system, an analysis of the water sampled from two individual wells was conducted using the indirect method recommended by Rajkovic and associates. Tests on the RDA and AAS showed that: Al, Fe, Cr, Pb and U were in concentrations higher than the values allowed by Regulations on the hygienic quality of drinking water. To determine the risk of the presence of toxic metals in the elevated concentrations, the assessment of short-term and long-term potential carcinogenic risks was conducted. Based on the results obtained in the tested water samples, it is noticed that the value of the coefficient of risk (CR) was less than 1 for all potentially toxic metals that were determined in drinking water, which implies that there is no short-term carcinogenic potential risk to human health. Based on the results of the long-term potential risk for the occurrence and development of cancer, the risk of getting cancer of Cr was identified in the inhabitants of the village that used potable water of the first sample. In case of Pb, a risk of developing cancer, concerning the first sample of drinking water, may occur in 44 out of 1000 people and regarding the second sample, in 183 out of 1000 people. Based on the calculated estimates of the long-term health risk related to the presence of U in drinking water, it can be seen that there is a health risk related to the use of both water samples. On the basis of the calculated estimates of the long-term health risk related to the presence of uranium in drinking water, it can be noticed that the use of both water samples may lead to the potential risk of developing cancer: in 24.5 inhabitants regarding the first water sample and in 10.3 out of 1000 inhabitants in the case of the second water sample. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43009]

This paper presents the application of cognitive radio technology in vehicular ad-hoc networks aimed to improve the communications between vehicles themselves as well as between vehicles and roadside infrastructure. Due to dynamic approach of spectrum access, cognitive radio is a technology that enables more efficient usage of radio-frequency spectrum. We review actual approaches and discuss research challenges related to the use of cognitive radio technology in vehicular ad hoc networks with emphasis on architecture, spectrum management as well as QoS optimization. The researching on cognitive radio application in vehicular networks is still developing and there are not many experimental platforms due to their complex setups. Some related research projects and cognitive radio realizations are provided in this paper.

Aflatoxin B1 adsorption by the concentrate of bentonite clay - montmorillonite and the natural zeolite - clinoptilolite and was investigated at the initial toxin concentration 4 ppm, with different amonunts of solid phase in suspension (10, 5, 2 and 1 mg/10 mL) and different pH values - 3, 7 and 9. Results indicated that for both minerals, decreasing the amount of solid phase in suspension, decrease the amount of active sites relevant for adsorption of aflatoxin B1. Thus, for concentrate of montnorillonite, at the lowest level of solid phase in suspension (1 mg/10 mL), aflatoxin B1 adsorption indexes were 97% at pH 3, 88% at pH 7 and 82% at pH 9, while for the natural zeolite, adsorption of toxin was 9% at pH 3 and 7% at pH 7 and 9. Since inorganic cations in minerals are mainly responsible for aflatoxin B1 adsorption, even the natural zeolite - clinoptilite has much higher cation exchange capacity (the content of inorganic exchangeable cations) compared to the concentrate of montmorillonite, adsorption of aflatoxin B1 by this mineral is much lower. Comparing the molecular dimensions of aflatoxin B1 molecule with the dimension of channels of clinoptilolite and interlamellar space of montmorillonite it is obvious that this toxin is adsorbed only at the external surface of clinoptilolite while in the montmorillonite all active sites are equally available for its adsorption. Thus, the concentrate of montmorillonite posess by higher adsorption capacity for aflatoxin B1. Results presented in this paper confirmed the fact the differences in the structure of minerals led to their different efficiency for adsorption of aflatoxin B1. Mineralogical and chemical composition, determination of cation exchange capacity, etc., are very important parameters influencing the effectiveness of minerals as aflatoxin B1 adsorbents. [Projekat Ministarstva nauke Republike Srbije, br. 451-03-2802-IP Tip1/142, br. 172018 i br. 34013]

The purpose of this study was to investigate the adsorption properties of locally available lignocelluloses biomaterials as biosorbents for the removal of copper ions from aqueous solution. Materials are generated from juice production (apricot stones) and from the corn milling process (corn cob). Such solid wastes have little or no economic value and very often present a disposal problem. Using batch adsorption techniques the effects of initial Cu(II) ions concentration (Ci), amount of biomass (m) and volume of metal solution (V), on biosorption efficiency and capacity were studied for both materials, without any pre-treatments. The optimal parameters for both biosorbents were selected depending on a highest sorption capability of biosorbent, in removal of Cu(II). Experimental data were compared with second order polynomial regression models (SOPs) and artificial neural networks (ANNs). SOPs showed acceptable coefficients of determination (0.842 - 0.997), while ANNs performed high prediction accuracy (0.980-0.986) in comparison to experimental results. [Projekat Ministarstva nauke Republike Srbije, br. TR 31003, TR 31055]

Environmental pollution with radionuclides, particularly uranium and its decay products is a serious global problem. The current scientific studies estimated that the contamination originating from TENORM, caused by nuclear and non-nuclear technologies, has significantly increased natural level of radioactivity in the last thirty years. During the last decades all the more were talking about the "new pollutant" - depleted uranium (DU), which has been used in anti-tank penetrators because of its high density, penetration and pyrophoric properties. It is estimated that during the Gulf War, the war in Bosnia and Yugoslavia and during the invasion of Iraq, 1.4 million missiles with depleted uranium was fired. During the NATO aggression against the ex Yugoslavia in 1999., 112 locations in Kosovo and Metohija, 12 locations in southern Serbia and two locations in Montenegro were bombed. On this occasion, approximately 10 tons of depleted uranium were entered into the environment, mainly on land, where the degree of contamination ranged from 200 Bq / kg to 235 000 Bq/kg, which is up to 1000 times higher than the natural level. Fourteen years ago there was very little information about the behavior of ecological systems damaged by DU penetrators fired. Today, unfortunately, we are increasingly faced with the ―invisible threat" of depleted uranium, which has a strong radioactive and hemotoxic impact on human health. Present paper provides a detailed overview of the current understanding of corrosion and corrosion behavior of DU and environmental factors that control corrosion, together with indicators of environmental impact in order to highlight areas that need further attention in developing remediation programs.

Evolution towards the next-generation Internet assumes dynamic end-to-end (E2E) quality of service negotiation on the path between the two providers, which are interconnected by a number of transit providers. Negotiation is performed by means of an appropriate signaling protocol. Basic models for E2E service negotiation include: (1) the cascade model, which assumes that a single provider controls service negotiation on the path, and (2) the third-party (3P) model, in which the trusted intermediary performs service negotiation on behalf of all domains on the path. This article presents a comparative study of the aforementioned negotiation models, regarding transport of signaling traffic. The three realistic topologies of interconnected networks have been simulated, using the network simulator NS2. Particularly, we point out the applicability and deployment of the 3P model.

The paper describes in vitro model for the evaluation of ability of peach shell (unmodified and modified), prepared at the Institute for Technology of Nuclear and Other Mineral Raw Materials, Belgrade, to adsorb different mycotoxins. Peach stones were obtained from “Vino Župa” Company from Aleksandrovac, where they have been disposed of as by-products from their Juice Factory. After proper preparation, two sorts of peach shell particles were used: one as unmodified peach shell particles (PS) and another one obtained by acid modification, denoted as MPS. Adsorption of six mycotoxins: aflatoxin B1 (AFL), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZON), diacetoxyscirpenol (DAS) and T-2 toxin by PS and MPS was tested in vitro. Crude extracts of mycotoxins, produced at the Department of Microbiology of Bio-ecological Center, Zrenjanin, were used for adsorption experiments. The ability of binding mycotoxins was evaluated in the electrolyte 0.1 M K2HPO4, which pH value was adjusted to 3.0 and 7.0, respectively. Mass ratio of individual mycotoxin and peach shell samples was 1:5000. The experimental mixtures were incubated for 1 hour on a rotary shaker (185 rpm) at room temperature (22-25ºC). After incubation, the extractions of non-adsorbed mycotoxins from the filtrates were performed with organic solvents, and their quantification was done by thin-layer chromatography (TLC). [Projekat Ministarstva nauke Republike Srbije, br. TR 31003: Development of technologies and products based on mineral raw materials and waste biomass for protection of natural resources for safe food production i br. TR 31023: Reduction of toxigenic Fusarium species and their mycotoxins in production of safe cereal-based foods]

In the last decade, the pollution made by anthropogenic sources has reached large amounts with special attention on heavy metals because of their high toxicity, persistence and bioaccumulation tendency. Since the conventional methods for their removing are either too expensive or create large quantities of toxic sludge, the great attention has been paid to the new technologies such as biosorption, technology that use cheap, abundant, organic waste for sequestering pollutants from contaminated mediums. Among the other factors that affect biosorption process, pH value is one the most important because it directs both the metal solution chemistry as well as the activity of the biomass functional groups. In this paper the influence of pH value on biosorption of Cu (II) by unmodified low-cost lignocellulose biosorbent - peach shell (PS) particles, have been studied. The chemical composition of PS, point of zero charge (pHPZC) as well as its surface morphology is also presented. Results have showed that this biosorbent contains mainly cellulose and lignin, the components that carry the functional groups responsible for metal binding. Its multilayer surface contains many pores and channels that help diffusion in deeper layers and force biosorption process. Point of zero charge determination was performed with three different KNO3 ionic strengths: 0,1M, 0,01M and 0,001M. The obtained value for pHPZC was 4,75±0,1 and showed that this biosorbent is non-sensitive to ionic strength of electrolyte applied. Biosorption experiments were done with peach shell particles whose diameter was -0,5+0,1mm at 25oC . The initial copper (II) concentration was 50 mg/dm3 while the biosorbent concentration was 10g/dm3. Experiments were done with and without keeping pH constant. The influence of pH on biosorption process was examined in 2-6 pH range. The percentage of Cu (II) removed by PS, reaches its maximum at pH 6, with the 90,43% removing but this percentage can also be attributed to precipitating of metal at this pH value. However, under the same operational conditions, but at pH 2, the retention of copper is equal to 2,62%. The results also indicate that it is necessary to lead the biosorption process with keeping pH constant all the time, since the copper removal was about 46 % less when the pH value was not kept constant during the biosorption process. The pH value obtained as optimal was slightly higher than pHPZC value which indicates that electrostatic attraction is one of the possible binding mechanisms in biosorption process. The results have showed that the removal of Cu (II) with peach shell particles is very sensitive to solution pH and that this parameter should be thoroughly investigated and strongly controlled during the whole removal process.

The main aim of this study was to investigate the impact of the coal mine in Lazarevac, and the coal-fired power stations in Obrenovac, on the activity concentrations of radionuclides 40K, 238U, 232Th, and 137Cs in some parts of human food chain of people living in the surrounding area. The obtained results showed that natural environment around the examined coal mine and the coal-fired power stations are not significantly affected by the emission of primordial radionuclides. The activity concentrations of 238U in the soil around the open coal mine and the coal processing installations (66.4-76.0 Bq/kg) and in the soil around the coal-fired power stations (55.5-61.2 Bq/kg) were not significantly higher than the average values in Serbia. The significant increase in the activity concentrations of natural radioisotopes in the samples of soil, vegetation, and animal products, was not confirmed. Food of animal origin used in human consumption is safe, i. e. not contaminated by radiation. [Projekat Ministarstva nauke Republike Srbije, br. TR 31003 i br. TR34013]

Distribution of natural gamma-emitting radionuclides 238U and 40K were determined in the soil profiles from the peach-trees field on experimental farm Radmilovac, southeast Belgrade. Internal soil morphology has been changed in 1992. when soil rigosol type with deep Ap-horizon (0-80 cm) has been formed by special treatment of parent soil, chernozem type. Gamma-spectrometry method is applied in measurement of radionuclide activities in soil samples by using hyperpure coaxial gamma-ray detector, Canberra type. Investigation results has been shown that the natural activity contents obtained in the experiment are within the range of normal background activity according to UNSCEAR (2000) and that radionuclide activity decreased in the plant root zone. .

In this paper the analysis of strontium and uranium content in drinking water has been done, indirectly, according to the scale which originates from drinking water in water-supply system of the city of Belgrade. Gamaspectrometric analysis showed the presence of free natural radionuclide in low activities. The activity of 90Sr in scale which is 0.72±0.11 Bq/kg was determined by radiochemical. Because of the small quantities of fur in the house heater this activity can be considered as irrelevant, but the accumulation of scale can have intensified influence. In this paper, the analysis of effects of the radioactive isotopes presence (first of all 238U and 235U) in drinking water on human health has been done. .

The concept of fractional extraction from sediment — in our analyses it is scale, is based on the assumption that uranium with a solid substance conform bonds of different strength and that these bonds can be gradually fractionated by the action of reagents of increasing dissolving power whereby the separated phases of extraction are defined according to their function or the type of bond in that substance. The advantage of this analytical procedure is that it enables simultaneous observing of different forms of uranium emergence in sediment (solid substance), which cannot be achieved by using individual extraction methods. Using the method of fractional analysis, it has been found that uranium is mostly connected with mobile fraction - manganese and iron oxides (94.20 and 87.96 wt.%) which represents the fraction that is potentially accessible to human organism.

The analysis of scale originated from drinking water on the house water heater, showed that scale is basically calcium carbonate that crystallizes hexagonally in the form of calcite. Scale taken as a sample from different spots in Belgrade – upper town of Zemun (sample 1) and Pančevo (sample 2) showed different configuration although it came from the same waterworks. That indicates either that the water flowing through waterworks pipes in different parts of the city is not the same or the waterworks net is not the same (age, maintaining, etc). All the elements which are dominant in drinking water (Ca, Mg, K, and Na), and which could be found in water by natural processes, are by their content far below the values regulated by law. The analysis also showed the presence of many metals: Ti, Pb, Zn, Cu Li, Sr, Cd, and Cr in the first sample, which are not found in the scale taken near Pančevo. The results obtained by calculating the mass concentration in drinking water on the basis of scale content, showed that both waters belonged to the category of low mineral waters. Contents of inorganic substances in these waters (117.85 mg/dm3 for sample 1 or 80.83 mg/dm3 for sample 2) are twice lower than the values predicted by the legislation. Gammaspectrometric analysis indicates the presence of radioactive elements – uranium and strontium which can influence human health.

Telekom Srbija is the first operator in the Western Balkan region with its own Internet of Things (IoT) ecosystem. The ecosystem is characterized by the following features: multitenant IoT platform; Long Range Wide Area Network (LoRaWAN) connectivity; technology proven through industry use cases with a large number of sensor devices and the associated application software; platform and application programming interfaces (APIs) for fast implementation and integration of new commercial use cases, and large capacity for fast network deployment. On that way, business partners are provided with a powerful environment for implementation of different use cases. The first use case based on this ecosystem referred to preventing theft of the company's underground telecommunication infrastructure. This article represented the state-of-the-art, the IoT ecosystem of Telekom Srbija, and the use case regarding protection of the underground cable infrastructure. [ABSTRACT FROM AUTHOR]