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Fractal Analysis of Doped Strontium Titanate Photocatalyst
No full textIn this research, the doping of SrTiO3 with Mn4+ was performed in order to evaluate the potential application as a photocatalyst for the degradation of organic dye pollutants. Since photocatalytic activity depends on grain microstructure, fractal analysis was used to estimate the Hausdorff dimension to provide a more thorough investigation of Mn@SrTiO3 morphology. Structural
analysis by infrared spectroscopy indicated the incorporation of Mn4+ into the SrTiO3 lattice, while by using x-ray diffraction, the crystallite size of 44 nm was determined. The photocatalytic activity test performed on complex ethyl violet organic dye revealed potential for Mn@SrTiO3 application in water treatment. Based on fractal regression analysis, a good estimate was obtained for the reconstruction of grain shape, with a Hasudorff dimension of 1.13679, which was used to find the best kinetics model for the photodegradation reaction. The experimental data showed a nearly linear fit with fractal-like pseudo-zero order. These findings and applications of fractal dimensions could contribute to future characterizations of photocatalysts, providing a deeper understanding of surface properties and their influence on photocatalytic activity
Ru-doped TiO2: Novel photocatalyst for Reactive Orange 16 dye degradation
No full textContamination of wastewater and hence water in general has become a major concern
especially because of the immense use of highly toxic synthetic dyes. Stable,
environmentally friendly, and low-cost titanium dioxide has already been widely applied
in photocatalysis, which is an advanced water purification treatment. However, TiO2 is
poorly active in the visible light region but this issue can be overcome by doping with
transition metal ions [1]. Hence, this work aimed at preparing Ru-doped TiO2
photocatalyst for dye degradation which will be highly active under simulated solar light.
To synthesize Ru-doped TiO2, the suspension containing TiO2 (anatase) and RuO2 in
mole ratio 5:1 was hydrothermally treated at 180 °C for 48 h. The pH value of the
suspension was adjusted to 13 by adding the potassium hydroxide solution
(c=0.4 mol dm–3
). The obtained powder was dried at 25 °C for 24 h and characterized by
XRD and TG/DTA while its photocatalytic activity was examined towards the
degradation of Reactive Orange 16 dye.
XRD results showed that the prepared sample consisted of the single-phased anatase
(PDF #64-0863). Calculated unit cell parameters and volume (a=3.8028(2) Å,
c=9.5046(7) Å, V=137.45(1) Å
3
) were higher than expected for the undoped anatase
meaning that Ru4+
-ions were likely incorporated into TiO2 lattice. Namely, the
octahedrally coordinated Ru4+ is larger (r=0.620 Å) than the octahedrally coordinated
Ti4+ (r=0.605 Å) so the lattice had to be expanded to accommodate a larger cation. The
crystallite size of the obtained Ru-doped TiO2 was sufficiently small, i.e. around 25 nm,
which is important for photocatalytic application. Photocatalytic activity tests confirmed
that the Ru-doped TiO2 could be used as a photocatalyst since 61 % of the dye was
degraded after 180 min under simulated solar light
Variation in Chemical, Textural and Sensorial Traits Among Remontant Red Raspberry (Rubus idaeus L.) Cultivars Maintained in a Double-Cropping System
No full textRemontant raspberry cultivars originally produce fruit in the upper part of primocanes in the fall, but if retained over winter, they can produce a second crop in the lower part of the floricanes the following spring. Maintaining remontant cultivars to yield twice during the cane’s growth cycle corresponds to a double-cropping system, which enables an increase in the total yield and the extension of the fruiting season. To date, there is little information on changes in fruit quality
between primocane and floricane crops. The aim of this study was, therefore, to investigate variations in the content of sugars and organic acids, fruit weight, color and textural and sensorial attributes among five newly introduced remontant raspberry cultivars (‘Dafne’, ‘Kokanee’, ‘Paris’, ‘Versailles’ and ‘Primalba’) and the control cultivar ‘Enrosadira’. The specific aim was to evaluate how a double cropping system in each cultivar may affect the variability in quality traits between primocane and
floricane crops. The results showed a significant increase in fruit weight and individual and total
sugar content in primocane crops, while significantly brighter red-colored and firmer fruits were
observed in floricane crops. Cultivars did not differ from the control regarding total sugar content
and sweetness index, while the content of individual sugars caused greater variations. The highest
content of citric, malic and total acid (9.74, 1.42 and 11.25 mg 100 g−1 FW, respectively) were recorded in ‘Paris’, by which this cultivar was the only one distinguished from the control. ‘Dafne’ and ‘Versailles’ exhibited better internal and external fruit quality on primocanes, having significantly larger fruits (6.83 g and 6.37 g, respectively) and twice the increased sugar content. The lowest fruit weight was observed in ‘Kokanee’ for both primocane (4.63 g) and floricane (3.65 g) crops. ‘Kokanee’ and ‘Primalba’ also performed worse than the control for most sensory attributes in both seasons. Based on the analysis of the overall fruit quality linked to the appearance, texture- and taste-related attributes that affect consumer preference, cultivars ‘Enrosadira’, ‘Versailles’ and ‘Dafne’ stood out, while ‘Paris’ showed high uniformity in fruit quality between crops, but scored the worst according to the total quality index
Ammonium nutrition enhances rhizosphere mobilization and uptake of silicon in white lupin grown in low phosphorus soil
No full textBackground and Aims
While nitrogen (N) supply can enhance plant silicon (Si) accumulation, the mechanisms by which different forms of N affect Si mobilization in the rhizosphere are not well understood. This study aims to elucidate how pH changes induced by ammonium (NH4+) and nitrate (NO3−) affect Si availability in the rhizosphere, especially under low phosphorus (P) conditions.
Methods
White lupin (Lupinus albus) plants were grown in non-fertilized low-P soil, supplied with a low dose of N, either as NH4+ or NO3−, with or without supply of monosilicic acid. We measured Si levels in various rhizosphere soil pools, along with different plant and rhizosphere soil parameters.
Results
The addition of NH4+ significantly lowered rhizosphere pH and decreased both Si adsorbed to pedogenic Fe/Mn oxides and amorphous phytogenic Si, resulting in higher concentrations of plant available Si in the white lupin rhizosphere. This led to greater Si uptake and improved plant growth compared to both the –N and + NO3− treatments. The supply of Si further enhanced these effects, with NH4+ showing a consistently different pattern of influence compared to NO3−. Additionally, –N white lupin plants accumulated more P than those treated with N, while Si supply significantly improved P acquisition across all treatments.
Conclusions
Our study demonstrates that rhizosphere acidification induced by NH4+ nutrition can significantly enhance Si mobilization from the rhizosphere soil in the absence of Si supply and reduce Si adsorption when Si is applied. These findings may have practical implications for improving both Si mobilization in the rhizosphere and the effectiveness of Si fertilizers
Contribution of the assessment of the genetic potential of wild pear mother trees from the Landscape of outstanding features "Kosmaj"
No full textAutohtone vrste šumskih voćkarica predstavljaju važnu komponentu biodiverziteta, ali su često ugrožene, usled delovanja različitih biotičkih i abiotičkih
faktora. Na području Predela izuzetnih odlika „Kosmaj” evidentirane su sledeće šumske voćkarice: divlja trešnja, divlja kruška, brekinja i oskoruša, koje pripadaju
kategorijama ugroženih ili ranjivih vrsta na ovom području. U cilju procene genetičkog potencijala materinskih stabala divlje kruške sa područja Kosmaja, osnovan je
generativni test potomstva u rasadniku Šumarskog fakulteta. Analizirana je varijabilnost morfoloških svojstava jednogodišnjih sadnica 14 linija polusrodnika, evidentirano je preživljavanje sadnica, izmerene su im visine i prečnici u korenovom
vratu. Materinska stabla DK4, DK22 i DK23, na osnovu procenta preživljavanja i visokih vrednosti visina i prečnika u korenovom vratu sadnica linija polusrodnika,
izdvojila su se kao potencijalno superiornija. Genetički potencijal ovih materinskih stabala i njihovih linija polusrodnika, treba proveriti u narednim godinama, u
pogledu otpornosti na biotičke i abiotičke faktore, u testovima potomstva u rasadniku i na terenu.Native species of forest fruit trees represent an important component of biodiversity, but are often threatened by the effects of various biotic and abiotic factors. In the
Landscape of outstanding features “Kosmaj”, the following forest fruit trees were recorded: wild cherry, wild pear, wild service tree and service tree, which are among the endangered
or vulnerable species in this area. In order to assess the genetic potential of wild pear mother
trees from the Kosmaj area, a generative progeny test was established in the nursery of the
Faculty of Forestry. The variability of morphological characteristics of one-year-old seedlings
from 14 half-sib lines was analyzed, the survival of seedlings was recorded, and their height
and root collar diameter were measured. The mother trees DK4, DK22 and DK23 stood out as
potentially superior due to the percentage of survival and the high values for height and root
collar diameter of the seedlings of the half-sib lines. The genetic potential of these mother
trees and their half-sib lines should be tested in the coming years, with regard to resistance
to biotic and abiotic factors, in nursery progeny test and field trials
Looking Into How Nickel Doping Affects the Structure, Morphology, and Optical Properties of TiO2 Nanofibers
No full textIn this paper, we have systematically studied the structural, morphological, and optical properties of Ni-doped TiO2, synthesized via a simple, cost-effective electrospinning method followed by calcination at 500 C. The nanofibers with a core-shell structure were relatively homogeneous, smooth and randomly oriented, and there were no significant differences in fiber diameters due to Ni2+ content. Core loss mapping using electron energy loss spectroscopy confirmed an even distribution of titanium and relatively uniform nickel in the fibers. It was found that doping with 0.5 mol.% Ni2+ decreased the rutile content, while doping with 1 mol.% Ni2+ resulted in a pure anatase phase with a significantly increased specific surface area (36.6 m2/g). Further increase in Ni2+ content (3-10 mol.%) not only prolonged the response of TiO2 nanofibers to visible light, but also increased the specific surface area (49.5 m2/g), decreased crystallite size (7 nm), and increased rutile content in TiO2 (33 wt.%). Photoluminescence analysis revealed that doping TiO2 with different amounts of Ni2+ leads to a gradual decrease of emission spectra intensity and red shift in the maxima positions. The XPS results confirmed that as the Ni2+ content enlarged, the Ti2+ and Ti3+ content increased significantly, effectively promoting the formation of oxygen vacancies. Raman analysis showed that an increase in nickel content (3-5 mol.%) led to a decrease and shift in peak intensity due to Ti3+ formation and also the possible presence of NiTiO3 phases. HRTEM analysis showed that Ni was doped into the substitution sites of both the anatase and rutile TiO2 lattice but had a stronger influence on the distortion of the anatase phase. The photocatalytic activity of Ni-doped TiO2 nanofibers was explored by analyzing the degradation of an antibiotic, oxytetracycline, monitored in laboratory conditions under visible light irradiation. After 60 minutes of irradiation, the degradation of OTC with 1Ni-TiO2 reached 76.4% and with 10Ni-TiO2 70.5%
Multidoped CeO2 single-phase as electrolyte for IT-SOFC
No full textThis paper explores the application of nanosized, sintered, non-stoichiometric CeO2 with six dopants Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-δ (CNSGDY), synthesized via modified glycine-nitrate procedure (MGNP) and room temperature self-propagating reaction (SPRT) for fuel cells. The composition, microstructure, and morphology of CNSGDY samples were analyzed using XRD, Raman spectroscopy, SEM, and EDS. The concentration of O2− vacancies, enabling the improvement of ionic conduction, was measured by the deconvolution procedure of additional Raman modes (250 cm−1 (2TA), 560 cm−1 (2LA) and 610 cm−1 (2TO)) and total values for MGNP and SPRT CNSGDY were 15.89% and 16.06%, respectively. Electrochemical performance assessed through EIS ((Electrochemical Impedance Spectroscopy) in the 550–700 °C range revealed a maximum power density of 55 mWcm−2 at 700 °C with SPRT electrolyte. Additionally, the ionic conductivity of the samples was calculated, with the SPRT sample showing superior performance due to higher ionic conductivity values. Differences in power densities between Pt/SPRT/Pt and Pt/MGNP/Pt cells suggest electrode-electrolyte interface and film thickness impacts, guiding future research
Effect of pH on piroxicam interactions with Fe3+ ions in water
No full textPiroxicam (PRX) belongs to the oxicam class of nonsteroidal anti-inflammatory drugs (NSAIDs). It shows analgesic, antipyretic and anti-inflammatory effects [1]. PRX is amphiphilic, containing two ionizable groups (pKa 1.86 and pKa 5.46) [1], and heteroatoms available for coordination with different metal ions. In this study, interactions of PRX with Fe3+ ions were investigated in water at different pH values using UV-Vis spectroscopy and cyclic voltammetry (CV). The formation of a PRX-Fe3+ complex takes place at acidic pH values (pH 2, pH 4 and pH 5). In a neutral solution (pH 7) PRX is present in an anionic form favorable for coordination with metal ions, but its complex with Fe3+ is not formed due to the low solubility of Fe3+. CV measurements were performed at pH 4 and pH 5 to study the redox properties of PRX in the presence of Fe3+ ions. At pH 4, the presence of Fe3+ ions stabilizes PRX towards oxidation, while at pH 5 the interactions with Fe3+ ions make PRX more prone to oxidation, and this difference can be attributed to the presence of a higher amount of doubly deprotonated (anionic form) of PRX at pH 5 (pKa 5.46). The change in Fe3+ reduction potential was also detected, additionally indicating the formation of the PRX-Fe3+ complex. It has been shown that coordination of NSAIDs to metal ions changes the effects of these drugs improving their biological activity [2]. According to this, further characterization of PRX-Fe3+ complexes and examination of their biological activity can be of interest
ACCUMULATION OF HEAVY METALS AND HUMAN HEALTH RISK ASSESSMENT via THE CONSUMPTION OF FRESHWATER FISH Esox lucius
No full textThe aim of this work was to evaluate the impact of anthropogenic pollution on the bioaccumulation of heavy metals in the muscle of the northern pike (Esox lucius L.1758). The specimens were caught at the four sites of the Belocrkvan lakes. The heavy metal concentration was analysed and based on this, the estimated daily intake (EDI), target hazard quotient (THQ) and carcinogenic risk (CR) were calculated to assess the risk to human health. The results showed that the values of the calculated indices were acceptable, so that the consumption of northern pike muscle from the Belocrkvan Lakes should not pose a health risk
Unraveling the nano-biochar mediated regulation of heavy metal stress tolerance for sustaining plant health
No full textHeavy metal (HM) toxicity of agricultural soils poses a major risk to plant health, human life, and global food
chain. Crop output and health are negatively impacted when HM levels in agricultural soils reach hazardous
points. The nano-biochar (nano-BC) mediated stress tolerance has attracted growing scientific interest because
biochar has the potential to be a novel and sustainable solution that may be actively included into the development of sustainable agriculture and food production. At present, biochar is extensively employed as a powerful
tool to enhance sustainable agriculture with minimal impact on ecosystems and the environment. Nano-BC offers
improved surface area, adsorption and mobility properties in soil compared to traditional fertilizers. Furthermore, nano-BC may prove to be the most practical substitute for traditional waste management techniques
because of its affordability, sustainability, and environmental friendliness. In this review, we examine the
application of nano-BC in the regulation of HM stress tolerance for improving plant growth and development. We
focus on the impact of HMs impact on crop productivity, nano-BC amendments, their application, and production. The article also explores the nano-BC risk and toxicity. Through the perspective of multidisciplinary
research, this work highlights the significance of nano-BC as cutting-edge tools in the field of agriculture, igniting
a paradigm shift toward sustainable and stress-resilient farming syste