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Unveiling the paleosalinity constraints on southern peri-Pannonian lower Miocene lacustrine systems in Serbia and Bosnia and Herzegovina: Lopare (Dinaride Lake System) versus Toplica basin (Serbian Lake System)
No full textEarly Neogene saline lakes were widely developed across Central Paratethys, particularly across its „Dinaride-Anatolide landbridge" (area of Dinarides, Balkans). The constraints on Lopare (western part of Jadar block; eastern Bosnia and Herzegovina) and Toplica (Jastrebac Mt., central Serbia) Neogene paleolakes provide a better understanding of deep-time climate evolution. The study focused on early Neogene paleolacustrine configuration, paleogeography, and the factors affecting a considerable paleosalinity increase. The study integrated available records on the predominantly Lower Miocene sedimentary sequence by analyzing and interpreting several paleosalinity markers (inorganic geochemical proxies, mineralogical data). The constraints on paleosalinity markers are afterward coupled with rather complex tectonic inferences. The two wellbores drilled in the Lopare and Toplica basins expose Neogene sections from which the critical paleosalinity markers are extracted (drillhole depths up to 350 and 1000 m, respectively). The mineral searlesite (NaBSi2O5(OH)2), and high B/Ga, markers of alkaline and arid paleoenvironmental lacustrine conditions, suggested intense evaporation (frequent drought periods). The evaporation was associated with paleoclimatic conditions during the Miocene Climatic Optimum. The Early Neogene arid climate and frequent evaporation episodes resulted in significant salinization of the Lower Miocene Lopare lacustrine sequence. The salinity in the Lopare sequence changed its character between brackish and saline, as evidenced by S/TOC and Ca/(Ca + Fe) ratios (TOC—Total Organic Carbon). At the same time, the salinity in the early Toplica basin was significantly lower and characterized by freshwater and brackish environments. The salinity variations between Toplica and Lopare were further exposed by Fe/(Ca + Mg), (Al + Fe)/(Ca + Mg), and C-value, yielding the change in the (paleo)water column. These markers further indicated the influence of warm climate conditions, consistent with the Miocene paleoclimatic record. Regarding paleogeography and Early Neogene tectonics, the results showed that before the Middle Miocene Badenian transgression, the Paratethyan Sea had no interference with the investigated intramontane lacustrine basins
Seasonal trends in water quality and their implications for water treatment technology in drinking water production - abstract
No full textGlavni fokus u cilju zaštite vode je plansko i naučno zasnovano iskorišćavanje vodnih resursa, kao i primena i optimizacija tehnoloških postupaka za pripremu pitke vode. Proizvodni pogon „Makiš“, preradom sirove savske vode Degremon (franc. Degremont) tehnologijom, zadovoljava skoro 60% potreba grada Beograda za pitkom vodom. Upotreba koagulanta, flokulanta i hlora je neophodna kako bi kvalitet vode bio u skladu sa Pravilnikom o higijenskoj ispravnosti vode za piće (Službeni glasnik RS, br. 28/2019). Cilj istraživanja bio je da se analiziraju sezonski trendovi u kvalitetu sirove vode reke Save i njihove implikacije na tehnologiju prerade površinske vode, kroz ispitivanje korelacije između fizičko-hemijskih parametara sirove vode i utroška hemikalija (koagulant, flokulant i hlor). Korišćenjem Pirsonove korelacione matrice, utvrđena je međusobna povezanost kvaliteta sirove vode i količine primenjenih hemikalija, što omogućava optimizaciju tehnološkog procesa prerade i efikasnije upravljanje resursima.The primary objective of water protection is the planned and scientifically based management of water resources, along with the implementation and optimization of technological processes for drinking water treatment. The "Makiš" water treatment plant, utilizing Degremont technology, meets nearly 60% of Belgrade's drinking water requirements by processing raw water sourced from the Sava River. The application of coagulants, flocculants, and chlorine is critical to ensuring that water quality adheres to the standards outlined in the Book of Rules regarding the hygienic safety of drinking water (Official Gazette of the RS No. 28/2019). This study aims to analyze seasonal variations in the quality of raw water from the Sava River and their implications for surface water treatment technology by investigating the correlation between the physicochemical parameters of raw water and the consumption of treatment chemicals (coagulants, flocculants, and chlorine). By employing Pearson's correlation matrix, we can ascertain the relationship between raw water quality and the amount of chemicals used, facilitating the optimization of the treatment process and enhancing resource management efficiency
Perspektive veštačke inteligencije u osnaživanju osoba sa invaliditetom u Srbiji
No full textThe integration of artificial intelligence (AI) into assistive technologies represents a transformative advancement in enhancing the quality of life for persons with disabilities. This paper explores the multifaceted applications of AI, from aiding daily activities and providing personalized medical care, to improving social and emotional well-being. By examining AI-powered tools such as text readers, robotic assistants, and communication aids, the study high-lights how these technologies facilitate independence and better healthcare outcomes. A survey from 2022 focusing on Serbia explores how many basic digital literate persons with disabilities use AI-based communication aids, and how many are aware that AI is following their everyday activities. The study reveals a possibility of future high usage rates and positive impacts on persons with disabilities in Serbia. About 24.32% of them already utilize AI-based communication tools, mostly audio and text processing tools. In this paper we underscore AI’s potential to foster inclusivity and independence, which is an important topic that should be emphasized in the society today.Napredak veštačke inteligencije (VI) može dovesti do značajnog poboljšanja života osoba sa invaliditetom, a njena primena obuhvata dve glavne oblasti: medicinsku negu i personalizovane alate za svakodnevnu podršku. Roboti i aplikacije zasnovane na VI počeli su da se koriste kao pomoć u nezi i tretmanima pacijenata, posebno onima sa neurodegenerativnim bolestima te fizičkim i senzornim oštećenjima. U kontekstu medicinskih usluga, VI analizira zdravstvene podatke, prati stanje pacijenata i prilagođava planove lečenja. Ona može optimalno da dozira lekove i preporuči terapiju u skladu sa individualnim potrebama, što olakšava brigu o pacijentima. Njena pravovremena reakcija i efikasnost intervencije utiču na kvalitet života osoba sa invaliditetom. VI ima potencijal da transformiše pristup obrazovanju i kulturi, i da personalizuje obrazovne resurse, te prilagodi obrazovne materijale kako bi odgovarali jedinstvenim potrebama osoba sa invaliditetom. Tehnologija emocionalne VI omogućava robotima da tumače izraze lica, gestove i emocije, pružajući sveobuhvatnu podršku koja odgovara kako praktičnim tako i emocionalnim potrebama korisnika. U Srbiji je prepoznat potencijal VI za osobe sa invaliditetom, što se vidi u Etičkim smernicama za razvoj VI koje je usvojila Vlada Srbije. U radu je pokazano da 24,32% korisnika pomagala među digitalno pismenim osobama sa invaliditetom već koristi komunikacione alate zasnovane na VI. Većina ovih alata spada u grupe Mobilne i tablet aplikacije, i Konvertori teksta i zvuka, dok su ostali iz grupa Specijalizovani softver, i Hardver i druga fizička pomagala. Istraživanje je pokazalo da skoro dve trećine osoba sa invaliditetom koje koriste komunikacione alate koriste one zasnovane na VI, što ukazuje na to da je tehnologija VI prepoznata kod osoba sa invaliditetom u Srbiji. Istražena je i upoznatost sa zaštitom podataka, gde se pokazalo da su ispitivane osobe sa invaliditetom delimično upoznate sa tim na koji način algoritmi zasnovani na VI utiču na njihove online aktivnosti, kao što je rangiranje sadržaja na društvenim mrežama. Sa obzirom na sve navedeno, primena VI za potrebe osoba sa invaliditetom u Srbiji ima veliki potencijal, što prati trendove u razvijenim zemljama. Integrisanje VI u zdravstvo, obrazovanje i socijalnu zaštitu može značajno doprineti nezavisnosti, poboljšanju kvaliteta života i zadovoljenju složenih potreba osoba sa invaliditetom. Ujedno, ovakva perspektiva VI ukazuje na to da ona može postati transformišuća sila u promovisanju inkluzivnosti i nezavisnosti osoba sa invaliditetom u Srbiji, kao i u svetu
High efficiency solar light photocatalytic degradation of mordant blue 9 by monoclinic BiVO4 nanopowder
No full textThe research presented in this paper focuses on the influence of solution pH on the photocatalytic activity of
single-phase monoclinic BiVO4 nanopowder degrading highly toxic textile dye Mordant Blue 9 (MB9) under the
simulated solar irradiation. BiVO4 nanopowder was synthetized using a sonochemical route. The catalyst was
confirmed to be single-phase and have relatively high surface area with mesoporous nanoparticles with 50 nm in
diameter on average. Band gap was estimated to be 2.38 eV, proving high absorbance of the visible light.
Photodegradation was observed in different pH values (pH = 1, 6, 8, 9, 11, 13) and the mechanism was proposed.
Influence of catalyst concentration and its reusability at pH = 13 are also reported, showing no activity loss after
four cycles
Genetic diversity and virulence traits of Pseudomonas syringae pv. syringae isolated from various hosts in Serbia
No full textIn this study, we assessed the genetic relatedness of 11 representative Pseudomonas
syringae pv. syringae (Pss) strains isolated in Serbia from different herbaceous and
woody plant species, as well as one reference Pss strain, using various molecular tools
such as repetitive element palindromic PCR, arbitrarily primed PCR, insertion
sequences 50 PCR (IS50-PCR) and multilocus sequence analysis (MLSA). Their virulence
traits were also assessed by inoculating detached pear and lilac leaves, as well
as immature cherry fruitlets. The results indicated genetic heterogeneity among the
strains, which formed a complex network with prominent clustering patterns. While
four distinct groups could be recognised when comparative Pss strains from the database
were included in the analyses, the strains in focus of this study segregated into
two distinct genetic groups labelled PssG-2 and PssG-3. MLSA findings mostly
matched the IS50-PCR results, while virulence assays helped distinguish sweet cherry
(RE05, RE3) and pumpkin (PS-T71) strains as the most virulent. Only strain Pss25,
originating from pear, exhibited host specificity
FLEXIBLE AND BIODEGRADABLE PRESSURE SENSORS BASED ON CHITOSAN-GLYCINE REINFORCED WITH MXENE
No full textAs the demand for sustainable and eco-friendly electronics grows, biodegradable materials are receiving increasing attention for their potential in flexible sensing applications. This study focuses on the development of film composites based on chitosan (CH) and glycine (Gly), synthesized through a simple solution-casting method. Chitosan was first dissolved in a 1% v/v aqueous acetic acid solution, followed by the incorporation of glycine at varying weight ratios (CH:Gly = 1:0.2, 1:0.6, and 1:0.8). The thin films were characterized using optical imaging, atomic force microscopy (AFM), and X-ray diffraction (XRD) to assess their morphology and phase composition. Local mechanical and piezoelectric properties were evaluated through AFM-based techniques, including AM-FM viscoelastic mapping, PFM DARTSS, and PFM lateral DARTSS. These analyses confirmed that the CH:Gly compositions of 1:0.6 and 1:0.8 were suitable for use in pressure sensor applications, with potential for further modification.
The resulting solution was cast and dried in a desiccator for 48 h, producing uniform, free-standing films. Additionally, free-standing films from CH:Gly = 1:0.6 and 1:0.8 compositions were further modified by incorporating low concentrations of Ti3C2Tx (MXene) sheets (5 and 25 μg/ml). While MXene is not a piezoelectric material itself, it offers unique properties such as a large specific surface area, high conductivity, excellent hydrophilicity, and adjustable surface functional groups. These characteristics make MXene an ideal candidate for enhancing the performance of flexible pressure sensors. Specifically, MXene was used as a
8th Conference of the Serbian Society for Ceramic Materials
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nucleating agent to induce the β-phase polarity and enhance the piezoelectric output during compression by promoting electron transfer.
Square samples (2.3 cm × 2.3 cm) were fabricated and equipped with copper electrodes (2 cm × 2 cm) on both sides, connected via wires and encapsulated in Kapton for mechanical and thermal protection. The electrical output of the films was measured using a custom-built laboratory apparatus under mechanical stress induced by finger taps. To ensure a more uniform distribution of mechanical stress, additional tests were performed using a Quartz Impulse Hammer (KISTLER, Italy) with a 2 cm rubber end. The CH-0.6Gly-25MXene film demonstrated strong and reproducible responses in both finger tapping and hammer impact tests, with a sensitivity of 40 mV/N.
These results underscore the promising potential of CH-Gly-MXene composites as high-performance, flexible, biodegradable pressure sensors. They offer an optimal combination of high sensitivity, mechanical robustness, and environmental sustainability
Root exudates differently mobilize silicon from soil pools under low nutrient conditions
No full textThe availability of silicon (Si) to plants is often limited, as most soil Si is bound in primary (e.g., feldspar) and clay minerals, occluded in aluminium (Al) and iron (Fe)/manganese (Mn) oxides and hydroxides, or occurs in less soluble forms such as amorphous biogenic SiO₂ (e.g., phytoliths) and crystalline SiO₂ (e.g., quartz). A common plant response to nutrient deficiency is enhanced root exudation of low-molecular-weight (LMW) compounds. Recent evidence suggests that both rhizosphere acidification (Kostic Kravljanac et al., Plant and Soil 511:209-222, 2025) and root released carboxylates can mobilize soil Si (de Tombeur et al., Trends in Plant Science 26: 1116 1125, 2021), but the role of other LMW root exudates in Si mobilization remains unclear. To investigate this, we conducted a series of experiments using Si-accumulating crops (barley, wheat, and cucumber) subjected to phosphorus (P), iron (Fe) or zinc (Zn) deficiency to stimulate root exudation. Root exudates were collected over time and characterized: Fe-deficient cucumber exudates mainly contained carboxylates and riboflavin, while P/Zn-deficient barley root exudates mainly contained carboxylates and phytosiderophores. These exudates were used to extract Si from four soils varying in pH and clay content, with the findings further validated using individual components of the exudates. We also tested their ability to solubilize two forms of SiO₂, amorphous biogenic SiO₂ (phytoliths isolated from equisetum) and crystalline SiO₂ (quartz), which, together with mineral-bound Si, represent major soil Si pools. Our results demonstrate that root exudates can significantly mobilize Si, and that mobilization depended on soil pH and clay content. Moreover, exudates enhanced the solubility of amorphous SiO₂, particularly from phytoliths. In addition to carboxylates, both riboflavin and phytosiderophores contributed to Si mobilization, with phytosiderophores being particularly effective in mobilizing Si from quartz
Using comprehensive two-dimensional gas chromatography-mass spectrometry for screening of semi-volatile compounds in plants
No full textObjective
Plants emitted around 1700 semi-volatile organic compounds (semi-VOCs) [1]. The effect of
cerium oxide nanoparticles (nCeO2), widely used in cosmetics, electronics, pharmacy, fuel
additives [2], and paints due to their redox properties, on semi-VOCs in plants is unknown. Thus,
the presence of nCeO2 in the environment is inevitable, so it is necessary to analyze their
ecotoxicity. The aim of this research was the screening of semi-VOCs in wheat and pea using
comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS) to
investigate their qualitative changes after the plant treatment with uncoated (CeO2) and glucose-,
levan-, and pullulan-coated nCeO2 (G-CeO2, L-CeO2, and P-CeO2) [3].
Methods
During three weeks of plants’ growth, the nCeO2 were applied at a concentration of 200 mg/L
through the hydroponic solution. Methylene-chloride extracts of dried plant shoots were directly
analyzed by a GC×GC-MS spectrometer GCMS-QP2010 Ultra (Shimadzu, Kyoto, Japan) equipped
with ZX2 thermal modulation system (Zoex Corp.) as total ion chromatograms (TIC). The MS data
were collected using Shimadzu GC/MS Real-Time Analysis. Nonlinear principal component
analysis with optimal scaling was used for the evaluation of wheat and pea GC×GC chromatograms
and the confirmation of differences in chemical composition between untreated and treated plants.
Results
Results showed 108 semi-VOCs detected in wheat and 77 detected in pea samples. Although wheat
exhibited higher uptake of nCeO2, the coated nanoparticles had a more pronounced impact on the
chemical composition of pea. Most compounds detected in pea after L-CeO2 treatment and in wheat
after the treatment with L-CeO2 and P-CeO2 had significantly higher content compared to the
control plants. Unique fingerprint images were used for inter-cultivar recognition, while a semi-
VOCs profile was presented only as categorical variables.
Conclusions
The presented results showed that GC×GC-MS, as a powerful separation technique that can reach
unique separation resolution, may be useful as a screening method for monitoring the effects of
various abiotic factors on different plant species
Unpacking the link between flexible work arrangements and job stress: The mediating role of Job satisfaction among highly educated employees
No full textThe main objective of this research was to investigate the mediating role of Job satisfaction in the relationship between flexible working arrangements (FWAs) and Job stress. The main research question is: what is the nature of the effect of flexible working arrangements on Job stress and Job satisfaction, the effect of Job satisfaction on Job stress and the role of Job satisfaction as mediation in the relationship between FWAs and Job stress? The methodology consists of theoretical and empirical parts. The empirical research was performed on a sample of 448 highly educated employees who operate in Serbia. Sample collection lasted from April to July 2024 via G-Forms electronic questionnaire. The proposed relationships were tested by applying PLS-SEM method via SmartPLS software. The main findings of the research are that there are positive effects of Flexible work arrangements and Job satisfaction on Job stress, and Job satisfaction has an indirect effect on the relationship between Flexible work arrangements and Job stress. The results indicated a partial mediation; a noticeable reduction of job stress was observed among employees who are sati.sfied with their jobs because of the implementation of flexible work arrangements
Chemical profiling of bioactive metabolites from antagonistic Bacillus velezensis strains
No full textBacillus species are well-known for synthesizing a broad spectrum of secondary metabolites
with antimicrobial properties and plant growth-promoting potential. Among these, volatile
organic compounds (e.g. alkanes, alcohols, carboxylic acids, ketones) and lipopeptides (e.g.
surfactin, iturin, fengycin, kurstakin) are increasingly gaining attention for their potential
applications in biotechnology. In this study, we chemically characterized ethyl acetate extracts
of four Bacillus velezensis strains (P-FC 55, RD-FC 88, R-FC 102, and R-FC 114) with
confirmed antagonistic activity against Xanthomonas campestris pv. campestris, aiming to
reveal bioactive secondary metabolites potentially responsible for their antimicrobial effects.
The analysis was performed using Gas Chromatography/Mass Spectrometry (GC/MS) for the
detection of volatile organic compounds and Ultra-high-performance liquid chromatography
coupled to quadrupole time-of-flight tandem mass spectrometry (UHPLC Q-ToF MS) for
lipopeptide profiling. GC/MS analysis detected 96 compounds in the ethyl acetate extracts of
four tested B. velezensis strains. The most abundant compounds, each with a relative abundance
greater than 1% across all strains, included 2,3-butanediol, urea, phosphoric acid, succinic acid,
thymine, phenylalanine, 9H-purin-6-ol. The analysis also detected several unidentified
compounds (designated as MS 4 – 6, MS 8, MS 12–15, MS 20–24, MS 29, and MS 30), which
could not be matched with spectra from the used MS libraries. UHPLC-QToF-MS analysis
revealed only the presence of different isoforms of surfactin (C12–C17) in all four strains.
However, the exclusive detection of this lipopeptide family may be attributed to the specific
growth conditions applied, and it is likely that additional lipopeptides could be produced under
different cultivation conditions. In both types of analyses, none of the detected metabolites were
unique to any specific strain; all identified compounds were shared among the four B.
velezensis strains. Differences between tested strains were only observed in terms of the
abundance of detected metabolites. The results indicate that the identified compounds, known for their antimicrobial properties, may play a role in the antibacterial activity of B. velezensis
strains against X. campestris pv. campestris, highlighting their potential for development into
biopesticide formulations for use in black rot control