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SnO2 nanofiber thick films for ethanol sensing: preparation, characterization, and performance
No full textIn this study we report on ethanol sensing properties of tin oxide (SnO2) thick films prepared
from electrospun SnO2 nanofibers. In the preparation process, polyvinylpyrrolidone (PVP) and
tin (II) chloride dihydrate (SnCl2·2H2O) were separately dissolved in a binary ethanol (EtOH)
and dimethylformamide (DMF) solvent mixture. The electrospinning solution was prepared by
mixing and stirring PVP and SnCl2·2H2O solutions at 45 °C. Under controlled electrospinning
parameters and humidity (35-37% RH) the fibers were electrospun onto aluminum foil and
subsequently calcined at 550 °C. The structural and morphological properties of the resulting
SnO2 nanofibers were characterized using X-ray diffraction (XRD), Brunauer–Emmett–Teller
(BET) surface area analysis, scanning electron microscopy (SEM), and field emission scanning
electron microscopy (FESEM). For thick film preparation, the calcined SnO2 nanofibers were
dispersed in terpineol and the obtained paste was screen-printed onto Al2O3 substrates prepatterned
with interdigitated electrodes and integrated microheaters. The printed film was
heated at 160 °C for 1 hour to remove the organic binder and improve adhesion between the
sensing layer and the substrate. The sensor was tested at various ethanol concentrations (100,
10, and 5 ppm) and across a range of humidity levels (0% to 70% RH). The results showed a
significant decrease in sensor response, from 40.1 to 4.2, as ethanol concentration decreased.
Additionally, minimal variation in the sensor response was observed as humidity levels
increased from 30% to 70% RH, indicating the sensor's potential for reliable operation in
practical applications
Photocatalytic degradation of pharmaceuticals by hydrothermally obtained α-Bi2O3
No full textBismuth (III) oxide-based materials have recently garnered immense interest in the field of photocatalysis [1]. Since the occurrence of pharmaceuticals in wastewater has become a global environmental concern, this study aimed to synthesize a highly efficient Bi2O3 photocatalyst for pharmaceuticals removal. To synthesize Bi2O3, bismuth (III) nitrate pentahydrate was initially dissolved in a HNO3 solution (c=5 mol dm−3) and subsequently NaOH solution (c=10 mol dm−3) was added until pH was adjusted to 12. After 24 h of homogenization, the obtained suspension was hydrothermally treated at 120 °C for 12 h. Finally, the yellow product was rinsed with water and ethanol and dried at 100 °C for 1 h. The obtained powder was characterized by XRD, FTIR, FESEM, and UV/Vis methods while its photocatalytic activity was investigated under simulated solar light towards various pharmaceuticals: pantoprazole sodium, propranolol hydrochloride, and diclofenac sodium. XRD results revealed that a single-phased monoclinic α-Bi2O3 was obtained with the crystallite size of 49(1) nm. According to FESEM, the particles formed agglomerates of 2.5 μm. The band gap energy of the prepared α-Bi2O3 was 2.93 eV, particularly suitable for the photocatalytic application under solar light. After 300 min of irradiation, the obtained sample degraded 73.9 % and 56.7 % of pantoprazole sodium and propranolol hydrochloride, respectively. Furthermore, synthesized α-Bi2O3 demonstrated extraordinary photocatalytic activity towards diclofenac sodium by completely degrading it after 180 min of irradiation. This study revealed that, in the near future, the hydrothermally synthesized α-Bi2O3 photocatalyst can serve as an effective tool for pharmaceuticals removal from wastewater.
References
[1] T. Selvamani, S. Anandan, L. Granone, D. W. Bahnemann, M. Ashokkumar, Mater. Chem. Front. 2018, 2(9), 1664-1673
Increase in lipid portion of Phycomyces blakesleeanus biomass induced by vanadate uptake and accumulation
No full textFungi are ubiquitous micro-organisms involved in various environmental processes, with a particularly important role in the
transformation of metals and minerals, bioremediation and biomining. Filamentous fungus Phycomyces blakesleeanus is an
interesting model for investigating the interaction of fungi with various ecological factors, such as heavy metals, due to the
ease of its cultivation and fast growth. The present study deals with the interaction of increasing vanadate [V(V)] concentrations
with the mycelium of P. blakesleeanus in three distinct growth phases: mid-exponential, late exponential and stationary phase.
Mid- and late-exponential phase mycelium had a V content of nearly 1% after 24h incubation with 10mM V(V), and the uptake of
V(V) was accompanied by increased phosphorus uptake with both 5 and 10mM V(V). Fourier Transform Infrared spectroscopy
showed the increase of lipid portion in biomass compared to proteins and carbohydrates mainly with ageing, but also with
vanadate treatment. P. blakesleeanus is tolerant to high V(V) concentrations, and this study suggests its potential as V accumulator. In addition, the increase in lipid content calls for a closer examination of lipid content and fatty acid composition after V(V)
treatment and determination of their potential industrial utilization
Uticaj topografskih faktora i različitih tipova zemljišnog pokrivača na reproduktivni uspeh surog orla (Aquila chrysaetos L.) na prostoru jugozapadne i zapadne Srbije
No full textРазумевање различитих фактора који у значајној мери утичу на успех гнежђења птица грабљивица од кључне је важности за њихову дугорочну заштиту. У овом раду испитивано
је како топографске карактеристике и заступљеност различитих станишних типова утичу на успех гнежђења сурог орла у брдско- планинским пределима југозападне и западне Србије. Анализом је обухваћено 126 покушаја гнежђења (96 успешних и 30 неуспешних) на 31 територији сурих орлова у оквиру 11 узастопних репродуктивних сезона. У циљу идентификовања кључних фактора који утичу на продуктивност орлова, примењене су статистичке технике у виду линеарних мешовитих модела (GLMM) са агрегацијом као робусним приступом за избор одговарајућих модела и процену важности испитиваних
параметара. Анализирани су утицаји опсега надморске висине, броја станишних полигона,
те удела пољопривредних, урбанизованих (руралних), шумских површина, као и отворених
каменитих и травнатих терена, на исход гнежђења. Делимично урбанизоване површине,
дефинисане као сеоске заједнице разбијеног типа са пратећом руралном инфраструктуром,
показале су значајан позитиван утицај на успех гнежђења. Такође, присуство различитих
жбунастих заједница и шумских екосистема позитивно је утицало на коначан исход гнежђења. Изузев наведених, остале испитиване променљиве нису показале значајан ефекат на репродуктивни успех. Добијени резултати отварају питања о сложеним интеракцијама популације сурог орла и степена урбанизације на истраживаном подручју, подржавајући идеју интегрисаног приступа управљању стаништима која укључује одрживи
развој руралних подручја и заштиту кључних шумских екосистема као гаранта очувања популационе стабилности сурог орла
Calypso Bird Observatory – The Coming of Age of the Southmost Bird Ringing Station of Europe
No full textGavdos, believed to be Odyssey's mythical Ogygia, is a small, habitat-diverse island at the
southmost boundary of Europe, and the entry point for the northward bound migrants crossing the
open sea from Africa in spring. Its strategic location makes it an exceptional site for studying opensea bird migration along the Aegean flyway, a route that remains understudied despite its
significance for conserving millions of migratory birds breeding across Europe including Russia
and parts of Asia. This presentation highlights the evolution of the University of Crete’s research
station on Gavdos since its inception in 2002, its challenges, achievements and future prospects,
demonstrating its importance within the national as well as international research networks. We
provide an overview of annual ringing statistics of some 20.360 birds of 95 species ringed in 8
years (spring 2002-2004 and spring and autumn passage 2021-2024), phenology and parasite
loads, along with the human potential and currently running research programs. The locations of
the 15 long-distance recoveries are scrutinized with the known population-specific flyways given
in the Euring Bird Migration Atlas. Plans are presented for supporting collaborative research
networks and multidisciplinary programs in the frame of One Health initiatives for the study and
potential establishment of an early warning system regarding emerging zoonotic diseases. The
Calypso Bird Observatory plays an important role in advancing ornithological research in Greece,
emphasizing its contribution to conservation of migratory bird species and protected areas. Funded
by NECCA
Birds Arriving Depleted or Fuelled to Gavdos Island in Spring: The Perils and Advantages of Migratory Flights Over the Libyan Sea
No full textLong-distance flights over freezing altitudes, deserts, and open seas—supported by innate
compasses, learned navigation skills, and favourable weather—offer migratory species significant
fitness advantages. However, these journeys carry substantial risks along difficult stretches like
the Libyan Sea, where survival depends on critical staging sites. Trapping surveys reveal
emaciated birds and high mortality due to irreversible metabolic collapse caused by fuel reserve
depletion. Identifying and protecting such stopover sites is vital for conservation. Targeted
measures, such as habitat enhancement can provide life-saving food, water, and shelter. Despite
their importance, the role of Greece’s ~6,000 islands and islets remain largely understudied, even
under the Natura 2000 network. To address this, we investigated Gavdos—the southernmost point
of Europe, located 260 km north of Libya—as a stopover site for spring migratory birds. Using
fuel load data from 17,512 birds ringed over seven years, we replicated the analyses of a recent
study on energy-depleted migrants on Gavdos and two other southern Greek islands. We observed
significantly higher percentages of birds with depleted fuel reserves, with average fat and muscle
scores of 1.87 and 1.83, respectively, among newly ringed birds. Importantly, we correlated daily
energy status with the wind direction, underscoring the critical role of tailwinds in preserving the
metabolic integrity required for open-sea crossings. Our findings highlight the importance of longterm monitoring and comprehensive datasets for effective conservation strategies. Gavdos’
function as a critical stopover site reinforces the need for continued research and targeted action
to protect these sites. Funded by NECCA
Can’t Fly Upwind: Catastrophic Mortality of Migratory Birds on Gavdos Island in Spring 2024
No full textOn April 24th, 2024, an unseasonal shift in wind direction and strength from SE to NW across the
eastern Libyan and western Levantine Basin persisted for 13 days, until May 7th. These
unfavourable conditions forced migratory birds to extend their stay in North African staging sites
and/or endure prolonged, energy-draining flights over the sea. Waves of exhausted birds started
arriving on Gavdos Island from April 25th with individuals mist-netted for ringing carrying fat and
muscle scores below the metabolic threshold of 1, indicating severe energy depletion and potential
physiological collapse. Compounding the crisis, the scarcity of food and water caused by an
exceptionally dry winter and spring resulted in unprecedented mass die-offs through early May.
Additional factors included intensive cat and rat predation, traffic collisions and diseases caused
by immune-suppressive exhaustion. Locals described this event as the worst bird die-off in
decades, with gardens and orchards littered with carcasses, prompting some residents to bury
dozens of birds. The bird ringing team carried out a 2-hour carcass survey on May 3rd after ceasing the trapping efforts, recovering 105 complete carcasses of 21 species, along with dozens of partial
remains suggesting widespread cat/rat predation. The most heavily affected species included
Sylvia borin, Muscicapa striata, Hirundo rustica, Phylloscopus sibilatrix, and Merops apiaster.
This event highlights the severe impact of extreme weather on migratory species and underscores
the urgent need to improve habitat quality and protection at critical stopover sites like Gavdos.
Funded by NECCA
VARIATION AND MORPHOLOGICAL MANIFESTATION OF GERMLINE RESTRICTED CHROMOSOMES IN CLOSELY RELATED SPECIES OF LEAF WARBLERS OF GENUS PHYLLOSCOPUS IN ARMENIA
No full textThe family Phylloscopidae, commonly known as leaf warblers, represents a diverse group of small
insectivorous passerine birds. Over the past three decades, the family has undergone significant
taxonomic revisions, with the number of recognized species increasing by approximately 50%.
We focused our study in Armenia on the three species: Phylloscopus sindianus lorenzii, Phylloscopus collybita menzbieri and Phylloscopus nitidus. Two species Phylloscopus sindianus lorenzii and Phylloscopus collybita menzbieri diverged approximately 0.435 million years ago. In contrast, P. nitidus belongs to a different basal clade within Phylloscopidae, which diverged 11.7 million years ago.
The aim of this work was the first comparative study of meiotic karyotypes in closely related species of the genus Phylloscopus: Ph. collybita menzbieri, Ph. sindianus lorenzii, Ph. nitidus, which have significant differences in the morphology of the germline restricted chromosomes (GRCs) - an obligate element of the germ cell genome that can only be found in spermatocytes and oocytes but is eliminated in somatic tissues. These new avian marker chromosomes are of great interest to geneticists because they are highly variable but have been preserved in most passerines.
We conclude the tenfold difference in the sizes of the GRCs between Ph. collybita menzbieri, Ph.
sindianus lorenzii on the one hand and Ph. nitidus on the other. The different sizes of GRCs, apparently a result of deletions or insertions from A-chromosomes in closely related species and even intraspecific variability of GRCs are generally considered by researchers as non-critical changes for the species.
Bird karyotypes are considered to be relatively conservative and evolutionarily stable, while the
evolution of GRCs can occur very intensively even within closely related species, as shown by the
example of the three species of warblers in our study
Stabla "zapisi" Šumadijskog upravnog okruga i potencijal za njihovu zaštitu u kategoriji Spomenika prirode botaničkog karaktera
No full textPrema podacima Centralnog registra zaštićenih prirodnih dobara, pod režimom zaštite je 77 stabala ili grupa stabala u kategoriji Spomenik prirode botaničkog karaktera, od čega je oko 30 stabala „zapisa”. U periodu od marta do jula 2025. godine, metodom građanske nauke, uz aktivno učešće građana u terenskim aktivnostima, registrovano je 116 stabala „zapisa” na području Šumadijskog upravnog okruga, koji nisu pod zaštitom Zavoda za zaštitu prirode Srbije. Analizom prikupljenih podataka, utvrđeno je da 24 stabla poseduju dimenzije i karakteristike uporedive sa već zaštićenim „zapisima”. Ona poseduju ključna prirodna obeležja poput reprezentativnosti, raznovrsnosti bioloških i predeonih vrednosti, kao i estetske, odnosno pejzažne atraktivnosti, u skladu sa Pravilnikom o kriterijumima vrednovanja i postupku kategorizacije zaštićenih područja. Ovi „zapisi” odgovaraju opisu iz Zakona o zaštiti prirode za kategoriju Spomenik prirode botaničkog karaktera u dovoljnoj meri da zavređuju posebnu stručnu ocenu radi mogućeg kandidovanja nekih od stabala za ovu kategoriju. Od 24 stabla, 9 pripada krupnoj granici (Quercus frainetto Ten.), 6 meduncu (Q. pubescens Willd.), 2 ceru (Q. cerris L.), 2 lužnjaku (Q. robur L.), 2 oskoruši (Sorbus domestica L.), i po jedno stablo poljskom jasenu (Fraxinus angustifolia Vahl.) i crnom boru (Pinus nigra JF Arnold). Posebnu konzervacionu vrednost imaju stabla onih vrsta čija sustaništa u Šumadiji degradirana, kao što su izdanačke šume krupne granice i cera ili fragmentisana staništa lužnjaka na šumadijskim aluvijumima. Na osnovu utvrđenih bioloških karakteristika — vrsti drveća, obimu stabala na prsnoj visini, razvijenosti krošnje i prisustva mikrostaništa — „zapisi” Šumadijskog upravnog okruga predstavljaju botanički i kulturni fenomen od posebnog značaja
Protective role of Fe3+ ions against the photodegradation of meloxicam
No full textMeloxicam (4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide), a nonsteroidal anti-inflammatory drug (NSAID) of the enolic acid class was selected for therapeutic use due to its high anti-arthritic activity and broad-spectrum of anti-inflammatory effects in animal and cells models [1]. The widespread use of meloxicam (MLX) has led to its notable accumulation as a pollutant in aquatic and terrestrial environments, highlighting the urgent need for effective water treatment strategies to ensure its degradation and removal [2]. A detailed understanding of the coordination behavior and photochemical properties of MLX in the presence of ferric ions can offer valuable insights for enhancing iron-based advanced oxidation processes (AOPs) in wastewater treatment. In this study, chelation of MLX with ferric ions and effect UV irradiation on MLX in the presence of ferric ions were examined using UV-Vis spectroscopy at pH 5. In the presence of Fe3+ ions at pH 5, a coordination reaction occurs between the Fe3+ ions and MLX, probably resulting in the formation of the Fe3+-MLX complex. UV A and UV-B radiation can lead to the degradation of MLX. Additionally, the results show that in the presence of Fe³⁺ ions, the photodegradation effect is weaker compared to MLX alone. In other words, the Fe³⁺ ions form a complex with MLX and protect it from photodegradation. Therefore, the removal of MLX by Fe(III) photolysis is not the method of choice. The toxicity of MLX and its degradation products was ultimately evaluated using Artemia salina as a test organism, providing valuable insights into the potential environmental impact of the degradation process