Vinča Institute of Nuclear Sciences
Repository of the Vinča Institute of Nuclear Sciences (VinaR)Not a member yet
15953 research outputs found
Sort by
Synthesis, characterization and antioxidative capacity of nickel(II) and zinc(II) complexes with 4-methylpyrazole
No full textIn this paper, the coordination of 4-methylpyrazole (L) to Ni(II) and Zn(II) ions is studied through the reactions of Ni(OAc)2·4H2O and Zn(OAc)2·2H₂O with 4-methylpyrazole in a 1:2 metal-to-ligand molar ratio in ethanol at room temperature. From the reaction mixtures, new complex compounds of formulae: [Ni(OAc)2L4] and [Zn(OAc)2L2] were crystallized. The crystal and molecular structure of the synthesized complexes were determined by single-crystal X-ray structure analysis. The coordination environment of Ni(II) in its complex is octahedral, while that of Zn(II) is tetrahedral. The compounds are characterized by IR spectra and elemental analysis. Their thermal stability, a crucial property, is analyzed by thermogravimetry. To get a better insight into the decomposition mechanism coupled TG-MS measurements were carried out, too. The tests of the antioxidative activity of the new complexes on DPPH radical showed that the Zn(II) complex is more effective than the Ni(II) complex
Low-intensity exercise prevents cardiac inflammation through the NF-κB/TNFα pathway in insulin-resistant male rats
No full textOur previously published results have proven that low-intensity exercise, equivalent to brisk walking, is beneficial in managing cardiac insulin resistance in post-weaning male rats exposed to a fructose-rich diet. Still, its role in protecting against cardiac inflammation is unclear. This experiment was designed to investigate the preventive effect of low-intensity exercise on cardiac inflammation in male post-weaning rats exposed to a fructose-rich diet (10%). Male Wistar rats were randomly assigned to a sedentary control group, a sedentary group with fructose overload, and a fructose overload group subjected to treadmill exercise for nine weeks. Protein expression of cardiac inducible nitric oxide synthase (iNOS), matrix metalloproteinase 9, as well as cellular localization/phosphorylation of nuclear factor kappa B (NF-κB), and α1 and α2 subunits of sodium–potassium ATPase pump (Na/K-ATPase) was determined. Additionally, gene expression of tumor necrosis factor α (TNFα) and suppressor of cytokine signaling 3 (SOCS3) was examined. The results demonstrate that a chronic fructose-rich diet in sedentary rats elevates the expression of key inflammatory markers, including SOCS3, TNFα, NF-κB, and iNOS, as well as the plasma membrane α1 and α2 subunits. Exercise prevented alterations induced by a fructose-rich diet, except iNOS expression. Additionally, exercise increased the protein expression of the α1 and α2 subunits of Na/K-ATPase in the lysate of fructose-fed rats. These findings suggest that low-intensity exercise is an effective non-invasive strategy for cardioprotection, helping to prevent inflammation by modulating TNFα and NF-κB expression in insulin-resistant hearts of post-weaning male rats. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025
Two-dimensional Monte Carlo simulation of source-specific risks from PM2.5-bound polycyclic aromatic hydrocarbons in indoor and outdoor school environments
No full textProbabilistic health risks in school environments from fine particulate matter (PM2.5) bound polycyclic aromatic hydrocarbons (PAHs) emitted from specific sources were evaluated. The sixteen priority PAHs were examined in PM2.5 samples collected indoors and outdoors in the heating and non-heating seasons. The average concentrations of total PAHs (ΣPAHs) bound to PM2.5 were lower indoors than outdoors, with ΣPAH concentrations being notably higher in the heating season (11.1 ± 2.3 ng/m3 indoors and 12.5 ± 4.2 ng/m3 outdoors) than in the non-heating season (8.2 ± 1.6 ng/m3 indoors and 9.9 ± 3.0 ng/m3 outdoors). Acenaphthene, benzo[b]fluoranthene, and benzo[k]fluoranthene were the most abundant PAHs. Diagnostic PAH ratios and positive matrix factorization indicated that vehicular emissions and natural gas, biomass, and coal combustion were the major sources of PAHs during the heating season, whereas traffic was the primary PAH source in the non-heating season. The average total carcinogenicity, estimated using benzo[a]pyrene (BaP) equivalents, was 0.99 ng/m3 indoors and 1.1 ng/m3 outdoors for ΣPAHs, whereas BaP and dibenz[a,h]anthracene were the highest risk contributors. Two-dimensional Monte Carlo simulation revealed the average lifetime lung cancer risk (LLCR) due to exposure to PAHs in school environments of 8.65 × 10−5 indoors and 9.63 × 10−5 outdoors. In addition, the 95th percentile of the LLCR was found to be 8.86 × 10−5 for indoors and 9.91 × 10−5 for outdoors. These results suggest that the inhalation exposure of students to PAHs bound to PM2.5 poses potential health risks but remains below the serious risk level. © 2025 Elsevier Lt
Development and Characterization of Basalt-Based Glass-Ceramic Composites for Extreme Environment
No full textThis study presents the synthesis and characterization of durable basalt-based glass-ceramic materials and composites tailored for chemically and mechanically aggressive conditions. Utilizing basalt rock from the Vrelo deposit in Serbia as the primary precursor and iron mine tailings from the Bor mining region as a sustainable additive, glass-ceramics were produced via high-temperature melting, quenching, and controlled thermal treatment. Comprehensive analyses, including DTA, XRD, HT-XRD, FTIR, and SEM/EDS, confirmed the formation of fine-grained pyroxene-type silicates, predominantly diopside and augite, with no compromise in microstructural integrity due to tailings incorporation. Chemical durability was assessed through immersion tests in aqueous solutions at pH 3, 7, and 12 for up to 30 hours. ICP-OES analysis revealed minimal elemental leaching, and SEM/EDS verified no surface degradation or compositional changes post-corrosion, underscoring exceptional chemical resistance. These findings highlight the potential of basalt-based glass-ceramics, enhanced by industrial waste, for applications in geotechnical barriers, chemical reactor linings, and waste containment systems, offering a sustainable and high-performance solution for demanding industrial and environmental challenges.26th YuCorr International Conference, November 3-5, 2025, Palić, Serbia
Engineering Charge Transfer in PLD-Grown STO Thin Films on Si(001) by an rGO Interlayer for Photoelectrochemical Hydrogen Evolution
No full textIn order to explore the influence of the crystalline and interfacial properties of the protective layer on the photoelectrochemical hydrogen evolution (HER) by a Si photocathode, a ∼10 nm-thick strontium titanate (STO) film was grown using the pulsed laser deposition (PLD) method on both bare and silicon substrates buffered with reduced graphene oxide (rGO) at 515 and 700 °C. The integration of STO involved a combination of spin coating of graphene oxide and SrO-assisted deoxidation of the silicon substrate. Postgrowth analysis revealed a smoother morphology and reduced roughness of the STO films grown on rGO-buffered regions, in line with the XRR results. The RHEED method revealed textured STO films grown at 700 °C on both bare and rGO-buffered silicon substrates. The best crystallinity of STO was observed for rGO/SrO-deoxidized silicon surfaces at 515 °C, showing sharp RHEED streaks, indicating a well-ordered surface structure and confirming the preferential (002) out-of-plane orientation observed in the XRD measurements. Linear sweep voltammetry (LSV) and chronoamperometry (CA) measurements demonstrated that the epitaxially protected photocathode exhibited superior enhancement of the HER compared to its nonepitaxial counterpart. The epitaxial photocathode exhibited a more positive onset potential and higher photocurrent density. The CA results of the epitaxial STO/rGO/Si sample revealed better stability over prolonged operation compared to the nonepitaxial photocathode, which showed a significant decline of current. The EIS results show that the presence of silicate/silicides hinders HER significantly, especially in the case of samples prepared at 700 °C, where the integrity of the layers may be affected by the solid-state reaction between STO and Si. The obtained results illustrate how the crystalline and interface structures of the STO films influence the HER and the corresponding charge transfer, thus contributing to the engineering of more stable and efficient PEC devices in the future
Tuning Emission Energy by Atomic Substitution in Cr3+-Doped K2ABF6(A = Li, Na; B = Al, Ga, In) Fluorides
No full textWe present results of the first-principles calculations within a density functional theory (DFT) framework of the electronic structure and parameters of the2E →4A2and4T2→4A2optical transitions of Cr3+ions in a series of fluorides with the general chemical formula K2ABF6(A = Li, Na; B = Al, Ga, In). Calculations for the undoped fluorides reveal that the energy band gap gradually decreases in the K2AAlF6→ K2AGaF6→ K2AInF6sequence. The theoretical data reveal for the Cr3+-doped K2ABF6fluorides new spin-up and spin-down electronic states related to the Cr3+3d-orbitals appearing in the host’s energy band gaps. The formation of the Cr–F chemical bonds due to the hybridization of the Cr3+3d- and F 2p-states is characteristic of the K2ABF6:Cr3+phosphors. The emission energy, Eem(2E →4A2), of the spin-forbidden transition increases with increased Cr–F bond lengths, while the crystal field strength 10Dq(4T2→4A2) parameter decreases in the K2AAlF6:Cr3+→ K2AGaF6:Cr3+→ K2AInF6:Cr3+sequence. Such theoretical attempts for the K2ABF6:Cr3+phosphors were performed for the first time, and these data provide a solid background for better understanding the physical properties of nondoped and Cr3+-doped K2ABF6fluorides, which are perspective phosphor materials. The calculations indicate also that in such a family of Cr3+-doped fluorides the emission energy can be successfully tuned by substitution of some kinds of atoms by their counterparts that can be useful also for exploring other related compounds as promising phosphors. From a practical point of view, the obtained relationships will allow obtaining the expected emission parameters through targeted optimization of the chemical composition. The presented computational approach can readily be applied to other optical materials without any restrictions related to the symmetry and chemical composition, providing an opportunity for precise determination of luminescent properties and allowing the targeted synthesis of efficient phosphors with expected properties and desired emission spectral distribution
Electromagnetic wave shielding effectiveness of the cotton fabrics functionalized with rGO and rGO-SmVO4
No full textDue to a high permanent magnetization and the stability of the permanent state, the samarium (Sm) based materials can be a potential novel class of electromagnetic shielding (EMI) materials [1]. In this work, the dispersions of graphene oxide (GO) reduced (rGO) by L-ascorbic acid (AA), and nanoparticles of samarium vanadate (SmVO4 ) were used for the continuous dyeing of cotton fabrics into 20 layers. A Keysight P5008A vector network analyzer was used to investigate the electromagnetic wave shielding effectiveness (EMW SE) of the cotton fabrics functionalized with rGO and rGO-SmVO4 . Measurements were conducted with a microwave coaxial probing set-up in the 6.5 GHz - 40 GHz frequency range. Previous testing showed that cotton fabric cannot block the propagation of EMW in the 8-12 GHz range. In the 6.5 - 40 GHz range, EMI SE of both textiles is above 77%. An average EMI SE for cotton-rGO is 14.1±1.9 dB, and cotton-rGO-SmVO4 is 14.7±2.0 dB. Results indicated that cotton functionalized with rGO showed outstanding shielding effectiveness in the wide frequency range. Furthermore, functionalization with magnetic rare-earth-based nanoparticles enhanced the ability of the fabric to block EMWs in the tested range.Twenty-sixth annual conference on material science (YUCOMAT 2025), Herceg Novi, Montenegro, 1-5 September 2025
Унапређење скретних, усмеравајућих и дистрибуционих елемената електрофилтерског постројења на блоку А2 ТЕ Никола Тесла
No full textTransportni procesi čvrstih čestica pepela u otpanom gasu postrojenja za sagorevanje mogu biti prirodni (usled dejstva gravitacione sile) i veštački (usled dejstva centrifugalne i elektrostatičke sile).Broj: TR 01/202
A Simple Virtual Sensor Approach for Black Carbon Estimation in Sensor Networks
No full textThis paper presents a simple virtual sensor predictive model based on multiple linear regression for the estimation of the equivalent black carbon concentration in an air quality automatic monitoring sensor network. The predictive model uses selected pollutants concentration and meteorological parameters as predictor variables, and equivalent black carbon concentration as target variable. Virtual sensor model is assessed for several different training/test periods. Dataset for training and validation of the model is derived using a vast dataset collected in WeBaSOOP project on Ada Marina, Belgrade supersite
Influence of iron on the mullite formation
No full textInfluence of iron on the crystallization mechanism of mullite obtained from the hybrid gels and doped with different concentrations of iron was examined. DTA analysis showed that iron addition had a beneficial effect on the mullite formation leading to the temperature decreasing as the amount of iron increased. X-ray diffraction and Mössbauer spectroscopy confirmed the increased iron content in the mullite lattice, which led to an increase in the unit parameter and was related to the higher iron content in regular octahedra, disordered octahedra, and tetrahedra with oxygen vacancies. Plate-like morphology observed by SEM suggests the two-dimensional crystal growth (n = 2). The most prominent kinetic models were used to estimate n and Ea from the DTA curves. Ea values increases as iron content increase, indicating that mullitization slows down due to iron incorporation. The Ea values for the undoped mullite sample ranged from 820 to 860 kJ/mol, from 820 to 890 kJ/mol for the iron-doped mullite sample containing 6.0 wt% of Fe2O3, and from 960 to 1060 kJ/mol for the iron-doped mullite sample containing 12 wt% of Fe2O3.Утицај гвожђа на механизам кристализације мулита додијеног из хибридних гелова допираних различитим концентрацијама гвожђа испитивани су методом диференцијалне термијсе анализе (ДТА). ДТА метода је показала да додатак гвожђа има позитиван утицај на формирање мулита што се потврђује смањењем температуре формирања са повећањем концентрације гвожђа. Рендгенском дифракцијом и Мезбауеровом (Mössbauer) спектроскопијом потврђено је повећање садржаја гвожђа у кристалној решетки мулита, што доводи до повећања параметара решетке, а у вези је са већим сарджајем гвожђа у регуларним октаедрима, октаедрима нарушене структуре и тетраедрима са кисеоничним вакансијама. Морфологија плочастих честица, која је потврђена скенирајућом електронском микроскопијом, указује на дводимензионални раст (n = 2). За одређивање Аврамијевохг коефицијента (n) и енергије активације (Eа) из резултата ДТА коришћене су најпознатији кинетички модели. Вредности енергије активације процеса формирања мулита расте са повећањем сарджаја гвожђа, што указује да се процес мулитизације успорава због уградње гвожђа у кристалну решетку мулита. Енергије активације за узорка недопираног мулита варирају у опсегу 820 до 860 kJ/mol, за узорак са 6.0 mas % Fe2O3 820 до 890 kJ/mol, док су за узорак са 12 mas % of Fe2O3 у опсегу 960 – 1060 kJ/mol