Due to high water content, chokeberries (Aronia melanocarpa L.) are perishable. Therefore, energy-saving, combined drying technologies have been explored to improve the chokeberry drying. The combined microwave and the traditional convective drying method (MCD) have significantly enhanced the drying effectiveness, efficiency, and energy utilization rate and improved product quality. The MCD method, which implies the microwave power (MD) of 900 W for 9 s and the convective dehydration (CD) at 230 °C for 12 s, has the shortest dehydration time t (24 ± 2 min), has the maximum coefficient of diffusion (Deff = 6.0768 × 10−9 ± 5.9815 × 10−11 m2 s−1), and represents the most energy effective for dehydration process (Emin = 0.382 ± 0.036 kWh). A higher water-holding capacity (WHC) characterized the chokeberries obtained by the MCD method compared to the regular microwave method (MD). The mildest MCD (15 s of MD on 900 W, 7 s of CD on 180 °C) could dehydrate chokeberries with the highest WHC (685.71 ± 40.86 g H2O g−1 d.m.) and the greatest evaluations for sensory attributes in terms of all properties. The results of this study provide the drying behavior of chokeberries that can help develop efficient drying methods and improve existing ones.

The efficiency of wastewater treatment is not only measured by the quality of treated wastewater, but also by the efficiency of treatment and permanent disposal of sludge that is separated. In addition to harmless, the sludge also contains hazardous substances that are released from wastewater during treatment. This work aims to obtain a neutral and harmless product by treating waste sludge with a stabilization and solidification process using modified MID-MIX technology. Physico-chemical analysis has shown that the obtained solidification or neutral, completely inert material, which has a use-value, can be safely disposed of in a sanitary landfill following EU (European Union) regulations. In terms of chemical composition, it is a mixture of crystal-bound organo-calcium, hydrophobic salts with a low moisture content of 5.8%. The results show that the method is the most environmentally friendly and most economical for the treatment of sludge, which can be applied to other types of waste with minor modifications.

Hidroelektrana Pirot, koja je izgrađena 1990 godine, je akumulaciona elektrana derivacionog tipa, koja se sastoji od dva nadzemna vertikalna agregata sa Francis turbinama nominalne snage 41,5 MW, proizvedene u Češkoj Republici, tunela i ukopanog cevovoda ukupne dužine 2030 m i prečnika od Ø 3000 mm do Ø 3500 mm. Cevovod debljine lima 22 mm je izrađen od čelika kvaliteta S275J2G3 (stara oznaka Č.0462). Maksimalni pritisak u njemu ispred turbinskog zatvarača je 2,5 MP.Cevovod je projektovan i izgrađen bez ankernih blokova na prelomima, što pretstavlja retkost u svetu. Na cevovodu se u kontinuitetu od završetka izgradnje i puštanja u rad sprovode geodetska merenja kada je cevovod prazan i neopterećen hidrostatickim pritiskom i kada je cevovod pun. Pregledom i analizom dobijenih podataka o pomeranjima duz trase cevovoda utvrđeno je da od 2003-2004 godine postoje znatno veće razlike u pomeranjima za pun i prazan cevovod, nego u prethodnom periodu. Te razlike se prvenstveno odnose na tangencijalna pomeranja za temena oznake 6, 7 i 8, koja se u odnosu na period do 2002 godine kreću od 3 mm za teme 8 do 5 mm za teme 6. Pored geodetskih merenja u kontinuitetu se, sa unutrašnje strane cevovoda, sprovode i merenja promena horizontalnih i vertikalnih prečnika. Iz tih podataka se moze videti da u periodu 2003-2004 godine postoji i značajan trend povečanja horizontalnih, kao i manje izraženo smanjenje vertikalnih prečnika.U radu je izvršena analiza trenutnog stanja i ocena integriteta cevovoda kao celine na osnovu rezultata ispitivanja vitalnog sučeonog zavarenog spoja metodama bez razaranja u zoni preloma na stacionaži -dužini cevovoda 1+263 m (vizuelno ispitivanje, ispitivanje magnetnim česticama, ispitivanje penetrantima, ispitivanje ultrazvukom, radiografsko ispitivanje, metalografsko ispitivanje metodom replika).

Soil is one of the most important natural resources. Measurement of natural radioactivity in soil is very important to determine the amount of change of the natural background activity with time as a result of any radioactivity release. Coal mine and thermal power plant in Gacko field is a very important industrial facility. The content of radionuclides of the soil was examined at Gacko area, slag, ash and mullock dumps in thethermal power plant Gacko and soils of dumps in the process of re-cultivation. The gamma – spectrometric measurements were done in the Institute of Nuclear Sciences “Vinča” in Belgrade.Soil samples were collected in 2010/2014 at more locations in eastern part of Republic of Srpska. After removing the stones and vegetation, all soil samples for Gama spectrometric measurements dried up to 0 105 C, sieved, placed in the plastic 500 mL Marinelli beakers and left for four weeks to reach radioactive equilibrium. Given that there are no specific regulations in the Republic of Srpska, the concentration of natural and produced radionuclides in samples from the working and living environment of thermal power plants, comparison with literature data from the region and the world is one way of evaluating the impact of the plant's operation on the soils. The results point to the necessity of regular monitoring of radioactivity in eastern Herzegovina in order to assess the impact of the technologically increased natural radioactivity.

As part of the paper, an abbreviated technical analysis of coal in the Kolubara basin for three coal-bearing fields: "Veliki Crljeni Field", "Field B and C", "Tamnava-Western Field" was examined. The results of the technical analysis regarding its possibilities to obtain products with the highest possible calorific value through preparation and processing indicated that this coal is characterized by a high content of ash and coke, and lower values of UCV (upper caloric value) and LCV (lower caloric value). In addition to the high percentage of moisture, a larger amount of inorganic substances is present in some samples. The content of macroelements, of heavy metals, and other microelements were examined by "Veliki Crljeni Field". The chemical composition is dominated by Al, Si, Ca and Fe, and S. are more significant. In terms of geochemical characteristics of coal and complete chemical composition, significant differences are represented, both in their distribution in the vertical profile of the main coal seam and laterally. The results show that the differences are particularly pronounced in the contents of some elements, e.g. chromium, manganese, vanadium, arsenic, etc. An analysis of the impact of coal mining on soil degradation and the environment is given.