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Effect of Na doping and substrates type on structure and properties of La1-xNaxMnO3 thin films
No full textPerovskite-type LaMnO3 has been identified as a promising candidate
for magnetic memory devices due to its unique opto-magnetoelectric
properties. The structure of LaMnO3 enables the substitution of La2+
and/or Mn3+ ions with various cations, allowing for straightforward
manipulation of its opto-magnetoelectric properties. La-site doping
with lower valence cations is of interest, as it leads to the presence of
heterovalent manganese ions (Mn3+ and Mn4+) to maintain charge
neutrality. The so-called double exchange, i.e. electric charge transfer
between Mn3+ and Mn4+ via oxygen anions, is responsible for the
appearance of ferromagnetism, metallic conductivity, and colossal
magnetoresistance.
In this study, we prepared polycrystalline and epitaxial thin films of
La1–xNaxMnO3 (x = 0; 0.05; 0.10; 0.15; 0.30) from acetate solution
deposited by spin coating technique on various substrates (Si, Si/Pt
and SrTiO3 (001)). XRD, FE-SEM, AFM, and Raman spectroscopy
analyzed the films’ structure and properties. XRD analysis showed a
slight shift in the peaks` positions towards high 2?, revealing the
incorporation of Na ions (x?0.10) in the structure of LaMnO3. Magnetic
measurements confirmed the increase of the Neel temperature with Na
substitutions and the decrease of magnetic polarizations. The structure
and morphology of the films were examined and correlated with sheet
resistance and magnetic properties, considering the type and thickness
of the films
ASSESSMENT OF ALKALI ACTIVATED BINDERS BASED ON FLY ASH FOR IMMOBILIZATION OF CESIUM
No full textThe management of radioactive waste is a major challenge in the nuclear industry in order to protect human health and the environment. Radioactive waste has primarily been immobilized in Portland cement-based binders. However, for nuclides that are difficult to immobilize, such as cesium (Cs+), researchers have been studying alternative matrices for immobilization, such as alkali-activated binders. This study investigated the immobilization of Cs in binders based on alkali-activated fly ash (AAFA). The effectiveness of Cs immobilization was assessed by the leaching behavior of Cs according to the ANSI/ANS-16.1-2003 standard test, depending on the concentration of added Cs. The Cs leaching rate for the sample with 5 % Cs was higher than for the sample with 2 % Cs, probably due to a higher percentage of Cs+ ions physically encapsulated within the pores of the gel that formed as the main product of alkali activation reaction of FA. It was also determined that the addition of Cs, had no statistically significant effect on the compressive strength of the AAFA mortars. Based on the calculated leachability indexes of Cs (~ 10), which significantly exceeded the minimum required value of 6, it was concluded that AAFA binders can be utilized as a highly efficient matrix for immobilizing cesium up to 5 % concentration
Polyaniline/TiO2 heterostructure: the efficient photocatalyst for diazepam degradation under simulated solar light
No full textAs pharmaceuticals have become significant wastewater pollutants [1], the objective of
this work was to design efficient PANI/TiO2 photocatalysts for degradation of psychiatric
drug diazepam since both, titanium dioxide (TiO2) and polyaniline (PANI) are highly
appropriate for photocatalytic application. Hence, PANI/TiO2 heterostructures with
different amounts of PANI (0, 1, 3, 5 wt.%) were obtained by mixing TiO2 synthesized
by using hydrothermal method and PANI prepared via chemical oxidative
polymerization. The obtained samples were characterized by XRD, FT-IR, FESEM,
EDS, DLS, and UV/Vis methods, while their photocatalytic efficiency was examined by
UV/Vis and TOC methods. The tetragonal anatase with preserved structure was obtained
in all the samples, with crystallites sized of about 25 nm. EDS analysis revealed that the
PANI/TiO2 heterostructures were successfully formed. According to FESEM, TiO2
created spherical particles with an average size of 23 nm, while PANI consisted of fibers
with an average length of 300 nm. Interestingly, with an increase in PANI content,
particle size distribution was wider. According to the absorption spectra, the absorption
edge of PANI/TiO2 was shifted to the visible light region compared to pristine TiO2. All
the samples showed photocatalytic activity towards diazepam, while 1%PANI/TiO2 was
the most efficient by degrading 95.9% of this drug after 210 min under simulated solar
light. Moreover, this heterostructure showed high mineralization efficiency as well,
which was confirmed by TOC measurements. The performed kinetic analysis revealed
that the photocatalytic degradation of diazepam in this work can be well described by
pseudo-first kinetic order. The highest value of reaction rate constant (0.017(1) min−1)
was obtained for the 1%PANI/TiO2. Finally, based on scavenger tests and
electrochemical calculations, the diazepam photocatalytic degradation in the presence of
1%PANI/TiO2 heterostructure under simulated solar light follow direct Z-scheme type
of mechanism
TRENDS AND DYNAMICS OF THE AUTUMN MIGRATION OF THE SEDGE WARBLER Acrocephalus schoenobaenus OVER A PERIOD OF 30 YEARS
No full textSvake jeseni, širom planete milioni ptica se, kao odgovor na nepovoljne uslove sredine, sele sa
svojih gnezdećih teritorija ka zimovalištima. U proleće se seoba odvija u obrnutom smeru, ka
gnezdećim teritorijama. U Srbiji se jesenja seoba ptica prati u kontinuitetu već više decenija na
Ludaškom jezeru, gde su podaci o seobi trstenjaka rogožara Acrocephalus schoenobaenus
prikupljani u periodu od 30 godina (1993-2022). Upotrebom standarnih ornitoloških mreža,
postavljenih u trsci, ptice su hvatane od sredine jula do kraja avgusta. Dinamika jesenje seobe
prikazana je kroz frekvenciju broja uhvaćenih juvenilnih i adultnih jedinki u petodnevnim
intervalima, dok je migratorni trend izražen ukupnim brojem prstenovanih jedinki tokom
istraživanog perioda. U tridesetogodišnjem periodu ukupno je obeleženo 26.268 jedinki
trstenjaka rogožara od čega 20.604 juvenilnih i 5.664 adultnih. Selidbeni trend za ukupan
uzorak je pozitivan i statistički značajan (β = 0.008, t = 2.23, p = 0.03), ali sa slabom
varijabilnošću (R² = 0.161). Usled male varijabilnosti, na koju utiču faktori poput vremenskih
uslova, selidbenih putanja, faktora izazvanih ljudskim aktivnostima poput gubitka staništa i
svetlosnog zagađenja, broj jedinki uhvaćenih tokom jesenje seobe ne može se koristiti kao
pouzdan pokazatelj veličine i trenda gnezdeće populacije. Uprkos fluktuacijama uhvaćenih i
prstenovanih jedinki trstenjaka rogožara, u ispitivanom periodu je ustanovljeno da se jesenja
seoba odvija u jednom talasu za sve starosne kategorije, dostižući vrhunac seobe oko 10.
avgusta. Dobijeni rezultati doprinose boljem razumevanju selidbenih obrazaca trstenjaka
rogožara i ukazuju na značaj dugoročnog monitoringa za očuvanje ove vrsteEvery autumn, millions of birds across the globe migrate from their breeding grounds to
wintering areas in response to adverse environmental conditions. On the contrary, in spring,
they return to their breeding territories. In Serbia, autumn bird migration has been continuously
monitored at lake Ludaš for several decades, with data on the migration of the Sedge Warbler
Acrocephalus schoenobaenus collected over a 30-year period (1993–2022). From mid-July to
the end of August, birds were captured using standard ornithological mist nets placed in reed
beds. Autumn migration dynamics were analysed based on the frequency of captured juvenile
and adult individuals in five-day intervals, while the migratory trend was assessed using the
total number of ringed individuals over the study period. Over 30 years, 26,268 Sedge Warblers
were ringed, including 20,604 juveniles and 5,664 adults. Although the overall migratory trend
was positive and statistically significant (β = 0.008, t = 2.23, p = 0.03), it showed low variability
(R² = 0.161). This variability, influenced by factors such as weather, migration routes, and
anthropogenic pressures (e.g. habitat loss and light pollution), suggests that the number of birds
ringed during autumn migration cannot reliably indicate breeding population size or trends.
Despite yearly fluctuations, the results indicate that autumn migration occurs in a single wave
for all age groups, peaking around 10 August. These findings contribute to a better
understanding of Sedge Warbler migration patterns and underscore the importance of longterm
monitoring for the conservation of this species and its habitats
Assessment of the productive potential of field elm for ex situ conservation in the protected area ”Zvezdarska šuma” (Belgrade, Serbia)
No full textIn Serbia, Ulmus minor Mill. (field elm) is categorized as a rare and endangered species, being
impacted by Dutch elm disease. Within the protected area ”Zvezdarska šuma” (Belgrade,
Serbia), remaining individual trees and small groups (59 georeferenced trees in total) persist
in a fragmented spatial pattern, representing gene pool potentially valuable for the future
species’ adaptive potential. This study aimed to assess the productive potential of field elm
trees in the protected area ”Zvezdarska šuma” as a basis for ex situ conservation of the
endangered gene pool. Hardwood cuttings were collected from 18 phenotypically healthy
trees during February March 2025. The experimental setup for propagation was conducted
in March 2025 under controlled glasshouse conditions, using containers (35x25x14 cm) filled
with peat and perlite (1:4 ratio) as substrate and treated with rooting hormone (dry-dip
method, 0.4% IBA). Following root initiation observed in May 2025, the plants were
transferred to a controlled nursery environment for acclimatization. Preliminary data
collected in June 2025 indicated significant variation in rooting success among 18 genotypes,
with an average rooting rate of 18.44%, ranging from 10.00% to 45.31%. The productive
potential of the test trees will be further assessed in a green cuttings clonal trial and a
generative progeny test, both established in the nursery of the Faculty of Forestry in
Belgrade. The results presented herein represent only the initial phase of ex situ
conservation, which should be further expanded through the integration of in situ
conservation methods and continuous monitoring of the existing gene pool
Development of a biopolymer-based biopesticide with with Ailanthus altissima extract for sustainable control of Lymantria dispar in forest ecosystems
No full textThis work presents the development of a novel biopesticide formulation based on natural biopolymers (chitosan and gelatin) and plant extract from the invasive species Ailanthus altissima. The use of this extract is economically and environmentally justified, as it supports sustainability by utilizing a widespread weed. A key challenge with plant-based biopesticides is the instability of active compounds when exposed to environmental factors. This was overcome by incorporating the extract into a chitosan-gelatin biopolymer matrix, both of which are GRAS (Generally Recognized As Safe)-certified by the FDA (Food and Drug Administration). The resulting formulation enables controlled release and prolonged activity of the bioactive compounds. Laboratory testing against the spongy moth (Lymantria dispar L.) showed improved efficacy compared to the pure extract. Since A. altissima extract is not commercially available and such a formulation has not been previously tested for spongy moth control, this approach offers an innovative, non-toxic, and eco-friendly alternative with great potential for forest pest management
Plant Essential Oils as Biopesticides in Organic Agriculture
No full textTherapeutic Potential of Medicinal Plants: The Science Behind Natural Remedies, investigates the bioactive compounds and functionality of medicinal plants and herbs which are recommended to help certain health conditions and overall well-being while highlighting cultivation that can be done sustainably to promote biodiversity conservation
Pseudomonas syringae Population Recently Isolated from Winter Wheat in Serbia
No full textThe aim of this study was to identify the causative agent of bacterial blight and basal glume
rot of winter wheat that appeared in Serbia in 2023. To characterize the isolated bacteria
(eight isolates in total), their cultural, biochemical, pathogenic, and genetic characteristics
were examined. Based on the results of the LOPAT test, the isolates were classified into
Pseudomonas Group Ia. The syrB and syrD genes were simultaneously detected in six
wheat isolates—P0123, P0223, P0323, P0423, P0523, and P0823—while two isolates, P1123
and P1323, lacked both genes. Multilocus sequence typing (MLST) of the gapA, gltA, gyrB,
and rpoD genes identified six isolates (P0123, P0223, P0323, P0423, P0523, and P0823)
as Pseudomonas syringae pv. atrofaciens, whereas the remaining two isolates (P1123 and
P1323) were most closely related to P. poae. Phylogenetic analysis revealed three genetically
heterogeneous subgroups of P. syringae pv. atrofaciens among the wheat isolates from Serbia.
Pathogenicity tests demonstrated that wheat isolates are able cause disease on wheat
seedlings using three different inoculation methods: spraying the entire seedling, trimming
the leaves before spraying, and wounding the leaves with multiple needles followed by
spraying. Overall, isolates P0123 and P0423 were identified as the most virulent, inducing
pronounced blight symptoms on wheat seedlings. In contrast, isolates P1123 and P1323
were weakly virulent and are therefore considered to be secondary or accompanying factors
in plants already infected with more aggressive isolates, rather than primary pathogens
responsible for disease development. This study contributes to a deeper understanding
of the ecology, distribution, and pathogenic potential of bacterial communities associated
with wheat blight disease in Serbia
Screening for polysaccharide producers among four different natural isolates of fungi
No full textIntroduction: The traditional medicine of many cultures uses mushrooms to maintain and improve vitality and health. Their application as food is spreading even more around the globe. Of the many biologically active compounds present in them, the most abundant are polysaccharides, terpenes, phenols, lectin, etc. Polysaccharides are complex carbohydrates that play a key role in various biological processes. They are found in diverse forms across the natural world, with higher fungi being a notable source. The polysaccharides and mycelium biomass derived from these fungi have attracted considerable interest due to their various applications in the food and pharmaceutical sectors. Mycelial growth is greatly dependent on fermentation media and physical conditions. The present study aims to test the ability of four new isolates of higher fungi to produce intracellular (IPS) and extracellular (EPS) polysaccharides during submerged fermentatio
Application of Fluorescence Spectroscopy for Contaminants Determination in Food
No full textFood contamination can occur due to various factors, including the presence of residues from agrochemicals, toxins from microorganisms, and unintended leaching of packaging components into food. Numerous food contami-nants are carcinogenic, mutagenic, and toxicogenic, found in low concentrations, requiring selective detection methods. Fluorescence spectroscopy enables rapid, non-destructive and sensitive determination of contaminants in food samples. The advanced chemometric methods improve the accuracy of the obtained spectral results. This book chapter reviews the potential use of fluorescence spectroscopy for screening contaminants in various food products. The fluorescence spectroscopy based methods used for the detection of contaminants in crop seeds, meat, fish and milk products, beverages, etc. are presented. The advantages and drawbacks of the methods are designated. It also discusses how fluorescence spectroscopy can be utilized for in-line, on-line, and at-line analysis in industrial-scale process control. By integrating fluorescence spectroscopy into industrial processes, continuous mon-itoring and detection of changes, contaminants and process performance indicators can be achieved, enhancing food safety