Search

The nuclear industry generates significant radioactive waste (RW) amounts, with its safe disposal being a primary safety and environmental issue. RW management involves solidification and disposal, often in deep underground facilities. Cement mortar is commonly used for liquid RW solidification due to its cost-effectiveness and simplicity. However, Portland cement concrete production raises environmental concerns, such as CO2 emissions and natural resource depletion. Additionally, RW storage and disposal costs drive research into low-cost matrices, especially those made from final waste products. The main requirements for matrix materials for liquid RW immobilization, which accept the role of primary barrier, are compatibility with RW material, good mechanical properties, and resistance to chemical and biological agents. However, partially substituting cement with waste materials can reduce strength and durability, increase susceptibility to cracking, porosity, and corrosion, further leading to harmful substance release. The matrix material must demonstrate longterm stability under various environmental conditions, including changes in temperature, humidity, and exposure to radiation ensuring that RW remains stable and safe within the matrix for decades or centuries. In addition, factors such as groundwater infiltration and seismic activity should also be considered when evaluating the long-term effectiveness of a protective structure. To manage these hazards, the selection, treatment, and preparation of recycled waste are crucial, alongside with proper design and utilization of such concrete. Monitoring concrete performance over time and implementing maintenance measures are necessary to ensure the long-term durability and reliability of structures. This work aims to assess the overall impact of recycled materials utilized in liquid RW solidification matrix.

Praseodymium doped calcium hydroxyapatite (PrHAP) nanopowder was synthesized by the co-precipitation method and characterized by X-Ray Diffraction, Fourier Transform Infrared, and Fluorescence Spectroscopy. Characterization studies from XRD and FTIR spectra showed that obtained crystals are monophase hydroxyapatites and that the sample particles are of nano size. A fluorescence study has shown that PrHAP particles have fluorescent emission under UV‐ Visible excitation. These results may open new avenues for developing bioactive materials for bone regeneration and fluorescent probes for bio-imaging applications.

Linden honey represents a unique honey variety valued for its nutritional benefits, distinctive taste and aroma. Phenols, polyphenols, flavonoids, ascorbic acid and phenolic acids in honey have antioxidant activities. This study aimed to investigate the effects of linden honey on the activities of antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPx), as well as on the concentration of malondialdehyde (MDA) in individually housed animals. The investigated parameters were quantified using spectrophotometric method for determination of enzyme activities and MDA concentration in the blood. We found that treatment with linden honey in the socially isolated animals significantly increased the enzyme activities of CAT and GPx, and significantly decreased the concentration of MDA. The modulation of CAT and GPx activities in socially isolated animals treated with linden honey may be very important for understanding the role of honey in the capacity of antioxidant defense system to increase and maintain its stability in psychosocial stress conditions. Our results may be important in biomedical research for understanding the role of honey in the amelioration of oxidative stress.

Lanthanide-doped apatite biomaterials are highly promising in medicine because of their excellent chemical and optical properties. In this study, Eu(III)-doped fluorapatite particles have been successfully synthesized by a wet method at room temperature. The characterization study from XRD showed that obtained powder is monophasic fluorapatite. Biomaterials based on fluorapatite (Ca10(PO4)5F2) doped with lanthanide elements are ideal contrast agents for a variety of biomedical applications, e.g. detection, imaging, cell tracking, and therapy [1]. Eu(III) received a great deal of interest because of several desirable properties like emission in the visible region, long luminescent lifetime, and less sensitivity to quenching by singlet oxygen [2].

The applicability of solid bricks waste in geopolymerization technique was considered. Waste samples were characterized in terms of mineralogical composition by XRD prior to mechanical testing. XRD analysis showed that both brick samples contained anorthite, wollastonite, and mullite as the main components. The compressive strength investigation was carried out by screening method with three geopolymer mixtures. Geopolymer mixtures were prepared with alkaline activators; the mixtures were poured into molds and air-dried for 28 days. The compressive strength of samples was measured according to the standard SRPS EN 12390-3:2010 for cubic samples. The compressive strength values ranged from 9.8 MPa for the newer solid brick, 10.2 MPa for the older solid brick, and 10.5 MPa for the solid brick mix waste geopolymer sample. The most likely underlying reason for the higher compressive strength results of the older solid brick and the mixed sample is their mineral composition, i.e. higher proportion of aluminosilicate. However, all samples showed satisfactory compressive strengths, and it represents an excellent basis for further research.

Gabrovnica, uranium mine near Kalna in the Eastern Serbia was a natural ore with uranium content. Exploitation of the uranium ore in this region was started in the 1960s and it was terminated in 1996. The aim of this work was to analyze radiological characterization of environmental samples around uranium mine Gabrovnica. Soil samples were taken in the autumn of 2022 and spring 2023, while surface soil samples (Gabrovnička River) were taken continuously for six month (July-December 2022 and January-June 2023). All samples were analyzed in order to determine gross alpha and gross beta activities and measured on ultra low level gas proportional counter Thermo-Eberline FHT 770T.

Gasni proporcionalni brojač koristi se za određivanje ukupne alfa i ukupne beta aktivnosti u različitim matriksima kao i za određivanje aktivnosti antropogenog radionuklida 90Sr koji je čist beta emiter. Ovaj rad predstavlja pregled kontrole kvaliteta gasnog proporcionalnog brojača Thermo-Eberline FHT 770T i određivanja efikasnosti, koja se sprovodi sa sertifikovanim standardima 241Am i 90Sr. Brojač ima mogućnost simultanog merenja na 6 detektora i određivanja aktivnosti reda mBq. U radu su prikazani i rezultati sprovedene eksterne kontrole kvaliteta učešćem u interkomparativnom merenju 90Sr, ukupne alfa i ukupne beta aktivnosti u uzorcima vode, organizovanom od strane Međunarodne Agencije za Atomsku Energiju tokom 2022. godine.

Sprovedeno istraživanje je usmereno na analizu trenda promene ukupne alfa i ukupne beta aktivnosti u poljoprivrednom zemljištu i usevima višegodišnjeg oglednog polja. Analiza je urađena primenom akreditovane metode za određivanje ukupne alfa i ukupne beta aktivnosti u čvrstim matriksima. Merenja su obavljena u Laboratoriji za zaštitu od zračenja i zaštitu životne sredine Instituta za nuklearne nauke “Vinča” na niskofonskom gasnom proporcionalnom brojaču Thermo Eberline FHT 770T. Izmerene vrednosti ukupne alfa aktivnosti variraju od 158 Bq/kg do 324 Bq/kg i ukupne beta aktivnosti od 600 Bq/kg do 1324 Bq/kg za uzorke zemljišta. Za uzorke biljnih kultura vrednosti ukupne alfa aktivnosti su u intervalu od 5 Bq/kg do 167 Bq/kg suve materije, dok su vrednosti ukupne beta aktivnosti u intervalu od 180 Bq/kg do 584 Bq/kg suve materije. Rezultati istraživanja su značajni, jer daju osnovne radiološke informacije od vitalnog značaja za ispitivano područje. Ovo je prvi pokušaj generisanja osnovnih podataka o radijacionom opterećenju zemljišta i biljnih kultura poljoprivrednog ekosistema alfa i beta emiterima, koji su određeni skrining metodom za monitoring životnog okruženja., The conducted research is focused on the analysis of the trend of changes in gross alpha and gross beta activity in agricultural soil and crops of perennial experimental fields. The analysis was performed using an accredited method for determining gross alpha and gross beta activity in solid matrix. The measurements were performed in the Radiation and Environmental Protection Department in Vinča Institute of nuclear Sciences on a low-level gas proportional counter Thermo Eberline FHT 770T. The measured values of gross alpha activity varied from 158 Bq/kg to 324 Bq/kg, and from 600 Bq/kg to 1324 Bq/kg for the gross beta activity in soil samples. For plant samples, values ranged from 5 Bq/kg to 167 Bq/kg of dry matter, and from 180 Bq/kg to 584 Bq/kg of dry matter for gross alpha and gross beta activity, respectively. The results of the research are significant, because they provide basic radiological information of vital importance for the investigated area. This is the first attempt to generate data base on the radiation load of soil and crops of the agricultural ecosystem with alpha and beta emitters, which were determined by the screening method for environmental monitoring.

Brzi napredak elektronske industrije doveo je do generisanja velike količine električnog otpada pre isteka njegovog odgovarajućeg životnog veka. Nelegalno odlaganje starih monitora i TV ekrana, odnosno njihovih katodnih cevi (Cathode-Ray Tubes, CRT), predstavlja veliki problem po životnu sredinu iz razloga što je CRT otpad klasifikovan kao opasan zbog visokog sadržaja olova. Stoga, konačnom zbrinjavanju navedenog otpada mora da prethodi tretman u topionici kako bi se olovo odvojilo od stakla. Dosadašnju praksu u Republici Srbiji (RS) dodatno komplikuje nedostatak takvih postrojenja, što zahteva izvoz CRT-a u Zapadnu Evropu uz dodatni trošak. Dosadašnja istraživanja ukazuju na mogućnost primene CRT stakla u izradi opeka, keramičkih pločica, specijalnih prostorija za odlaganje nuklearnog otpada ili kao agregata u građevinarstvu. Takođe, delimična supstitucija cementa fino mlevenim CRT staklom smanjuje količinu njegove potrošnje povećavajući nivo održivosti ovakvog procesa. Ovaj rad se bavi istraživanjima upotrebe CRT stakla u cementnim materijalima, kako bi se procenila mogućnost njegove upotrebe u malter-matriksima za imobilizaciju tečnog radioaktivnog otpada., The rapid progress of the electronic industry has led to the generation of a large amount of electrical waste before the end of its useful life. Illegal disposal of old monitors and TV screens, i.e. their Cathode-Ray Tubes (CRT), represents a major concern for the environment being CRT waste is classified as hazardous due to its high lead content. Therefore, the final disposal of this waste must be preceded by treatment in a smelter in order to separate the lead from the glass. The current practice in the Republic of Serbia (RS) is additionally complicated by the lack of such facilities, which requires the export of CRT to Western Europe at an additional cost. Previous research indicates the possibility of CRT glass utilization in the production of bricks, ceramic tiles, and special rooms for the disposal of nuclear waste or as an aggregate in construction. Also, the partial substitution of cement with fine ground CRT glass reduces the amount of its consumption, increasing the level of sustainability of this process. This paper deals with the investigation of CRT glass usage in cement materials, in order to evaluate the possibility of its use in mortar-matrix for the immobilization of liquid radioactive waste.

Malondialdehyde (MDA) is the end product of lipid peroxidation and biomarker of free radicals. The aim of this study is to investigate the effect of honey on concentrations of MDA in plasma exposed to a therapeutic dose of radiation. In this experiment animals were divided into two groups: in CONTROL group the animals were given distilled water orally for 28 days, and HONEY group consisted of animals given 1,5 ml/kg honey orally for 28 days. Blood samples of both groups were collected from a rat's tail. All blood samples were exposed to radiation of 2 Gy. Malondialdehyde concentration in plasma was determined using spectrophotometric method. Honey treatment in the blood plasma exposed to a therapeutic dose of 2 Gy significantly decreased MDA level by 30 % compared with control group. The present results indicated that honey had an effect on the levels of MDA in plasma exposed to radiation., Malondialdehid (MDA) je krajnji proizvod peroksidacije lipida i biomarker slobodnih radikala. Cilj ovog istraživanja je bio da se ispita uticaj meda na koncentraciju MDA u krvnoj plazmi izloženoj terapijskoj dozi zračenja. U ovom eksperimentu životinje su podeljene u dve grupe: u kontrolnoj grupi životinje su dobijale destilovanu vodu oralno tokom 28 dana, a drugu grupu činile su životinje koje su tokom 28 dana dobijale oralno 1.5 ml/kg meda. Uzorci krvi obe grupe su sakupljeni iz repa pacova. Svi uzorci krvi bili su izloženi zračenju od 2 Gy. Koncentracija MDA u plazmi određena je spektrofotometrijskom metodom. Tretman medom u krvnoj plazmi izložen terapijskoj dozi od 2 Gy značajno je smanjio nivo MDA (30 %) u poređenju sa kontrolnom grupom.

Nanomaterials based on metal–doped fluorapatite (FAP) have attracted considerable interest as potential next–generation antimicrobial agents. In this study, Cu2+–doped FAP nanocrystals have been successfully synthesized by a neutralization method at room temperature. Their structural, optical, antimicrobial, and hemcompatible properties have been investigated. XRD, FTIR, FESEM, and N2 adsorption–desorption studies indicate the formation of single–phase FAP mesoporous nanopowders, composed of rod–like particles. TEM images confirmed the formation of nanorodes with a length of 60 nm and a width of about 18 nm. Rietveld analysis shows that the Cu2+ ions preferentially substitute Ca2 (6 h) sites in the hexagonal fluorapatite crystal structure. Fluorescence spectroscopy accompanied by MCR–ALS method confirms substitution of Cu2+ ions in FAP crystal lattice with extracting additional d–d band transition at green color from FAP broadband self–activated luminescence in violet–blue color. Antimicrobial studies conducted on Staphylococcus aureus, Escherichia coli and Micrococcus lysodeikticus showed that FAP nanopowder with the highest Cu2+ content have strong bacteriostatic action on Staphylococcus aureus bacterial strain in mediums containing nutrition matters. In addition, this sample in comparison to pure FAP achieved a high percentage of relative reduction of bacterial population for all three species, being >90% in most cases. Fungistatic action is noticed too, throwgh the slowing down mycelium growth of fungus Aspergillus niger, Aspergillus flavus and Penicillium roqueforti and reduction of sporulation of Aspergillus niger species. Cu2+–doped FAP nanocrystals shows a synergistic antimicrobial effect with Cu2+ and F− ions. Concerning the potential biomedical applications, the hemolysis ratios of the Cu2+–doped FAP samples were below 5%. The obtained results pointed out the possible use of the synthesized nanocrystals as broad–spectrum antimicrobial agents for various