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Global Market and Standardization in the Biofuels Industry
No full textThe growing global demand for energy, coupled with the limited natural resources and environmental burden of fossil fuels, has accelerated the development of sustainable alternatives, among which biofuels play a key role. This paper analyzes the global market for solid and liquid biofuels, with a specific focus on three regions: Europe, as an energy-dependent market; the United States, as one of the leading producers and consumers; and China, as the fastest-growing market in this field. Particular attention is given to standardization systems and key institutions, with the aim of enhancing regulatory coherence and support future development pathways within the biofuels sector. The obtained results will serve as a foundation for predicting future trends and guiding the strategic development of the biofuels industry
Polydisperse Pt Deposits Over TiO2-Nanotube-Array-Supported Ru Nanoparticles: Harnessing the Interfacial Synergy for Efficient Hydrogen Evolution Electrocatalysis
No full textDeveloping cost-effective precious metal electrocatalysts for the hydrogen evolution reaction (HER) is key to realizing the economic viability of acidic water electrolysis. Herein, galvanic displacement is employed for in situ formation of bimetallic Pt/Ru deposits on H-intercalated TiO2 nanotube arrays. It is found that a two-step procedure yields polydisperse deposits with a dominant fraction of Ru nanoparticles coated with atomic and subnanometric Pt islands. These Pt|Ru nanointerfaces induce charge transfer from Pt to Ru, which modulates the electronic structure of Pt sites for accelerated HER kinetics. By varying the platinization time in the second step, a balance between the exposure of catalytically active Pt|Ru nanointerfaces and the total number of Pt surface sites is achieved. The optimized composite, termed Ru-30min@Pt-30min, requires an overpotential of 58 mV to deliver a current density of 100 mA cm−2 in 1.0 m HClO4 and maintains performance stability and structure integrity under prolonged operation. Moreover, it presents a 3.5-fold increase in precious metal mass activity over Pt/C at η = 80 mV. Theoretical calculations reveal that the electronic interactions generated by Pt-modification of Ru and hydrogenated TiO2 surfaces provide multiple active sites with improved Hads energetics compared to pure Pt and Ru
Oenanthe isabellina (Temminck, 1829), a new bird species for the fauna of Serbia
No full textThe checklists of bird species in certain areas constantly change with time. Herein, we present a previously unknown member of the Serbian avifauna: Isabelline Wheatear – Oenanthe isabellina (Temminck, 1829). The described record with prior data provides valuable insight into the species’ geographical distribution changes in Southeast Europe. It confirms previous assumptions about ongoing range extension in the west-northwest direction. Additionally, it highlights the importance of periodic monitoring of specific areas like Important Bird Areas (IBAs) for documenting the change in bird distributions and abundance
Spectroscopic and Microscopic Study of Silicon-Lignin Interaction: Effects on Plant Cell Walls and Industrial Potential
No full textSilicon (Si) is one of the most abundant elements on Earth and plays a crucial role in plant biology. It is a beneficial element for plants, contributing to their mechanical support, enhancing grain yield, facilitating mineral nutrition, and bolstering stress response mechanisms. Si is present in plant cell walls (CWs), where it is covalently bound to polysaccharides and lignin. This incorporation strengthens CWs, increases mechanical resilience, and mitigates the effects of biotic and abiotic stresses. Despite its importance, the precise interaction between Si and the lignin formation process in CWs remains poorly understood. This study explores the interaction between Si and lignin model compounds during in vitro synthesis, with a particular focus on how Si concentrations modulate lignin polymerization dynamics over time. Fluorescence techniques (microscopy and spectroscopy), combined with FTIR spectroscopy and atomic force microscopy (AFM), proved effective in monitoring the effects of Si on molecular conformation and aggregation behavior. We investigated the interaction of SiO₂ (complexed with NH₄OH) with the peroxidase-catalyzed polymerization of a lignin monomer into a dehydrogenation polymer (DHP) as a model system. Three Si concentrations (0.1 mM, 0.6 mM, and 6 mM) were analyzed and compared with a pure DHP sample. Samples were monitored at three synthesis intervals: 1 minute, 4 hours, and 24 hours. Results demonstrate that lower Si concentrations promote the aggregation of lignin oligomers into larger particles, while higher concentrations increase oligomer repulsion, preventing particle growth. Fluorescence spectroscopy revealed that polymer fragments containing conjugated -C=C- and -C–C- bonds exhibit redshifts in the green region (500–520 nm), with the extent of the shift correlating to Si concentration. Fluorescence microscopy and AFM showed that samples with higher Si concentrations formed more compact structures, with increased rigidity attributed to Si binding. FTIR spectroscopy identified Si-specific bands (967 cm⁻¹ and 1093 cm⁻¹) in the final polymers, indicating Si’s integration into the lignin structure. Notably, Si did not form new intermolecular bonds but interacted with dimers formed during DHP synthesis, inhibiting the formation of larger lignin fragments. Bands above 1200 cm⁻¹ in the FTIR spectra of Si-containing samples became less prominent, suggesting a significant impact of Si on lignin chemistry. These findings provide valuable insights into the complex interaction between silicon (Si) and lignin, demonstrating Si’s role in restructuring lignin, shaping cell wall architecture, and improving stress tolerance—key aspects for advancing research in plant biology. Additionally, the exploration of lignin-silica composites offers significant potential, enabling the development of sustainable materials with diverse applications in industries such as construction, medicine, energy, environmental protection, and advanced technologies
ПРИМЕНА БИОМАСЕ РАЗЛИЧИТИХ КЛОНОВА ИЗ РОДА Salix L. У ПРОЦЕСУ ДЕКАРБОКСИЛАЦИЈЕ ПРИ ПРОИЗВОДЊИ ЕНЕРГИЈЕ
No full textBiomass is increasingly employed in diverse applications to achieve and enhance energy efficiency, owing to its carbon-neutral nature. This is attributed to the fact that the quantity of CO2 released during its combustion corresponds precisely to the amount absorbed by biomass during its growth. The objective of this study is to assess the energy efficiency of biomass derived from analysed clones of fast-growing willow species in co-combustion processes with lignite at varying percentage ratios. The primary goal is to enhance the calorific value of lignite, optimize combustion and mitigate the harmful effects of combustion. The obtained results indicate that the calorific value of willow is higher than the calorific value of coal. The calorific value of coal (lignite) depends on the location of the coal deposit (field), while the calorific value of willows depends on the type of willow. Notably, clones 347 and NS 73/6 of white willow (Salix alba), have the highest energy potential compared to clones B-44 of white willow and basket willow (Salix viminalis).Биомаса се све више користи у разним видовима добијања или повећања енергетске ефикасности јер је карбонски неутрална, односно количина CO2 која се ослободи приликом њеног сагоревања представља исту ону количину коју биомаса апсорбује током свог раста. Циљ овог рада је да се испита каква је енергетска ефикасност биомасе анализираних клонова брзорастућих врста врба у процесима косагоревања са лигнитом у различитим процентуалним односима, а све у циљу повећања калоријске вредности лигнита бољег сагоревања и смањења штетних ефеката сагоревања. Добијени резултати указују да је калоријска вредност врба виша од калоријских вредности угља. Калоријска вредност угља (лигнита) зависи од налазишта угља (поља), док калоријска вредност врба зависи од врста врба. Утврђено је да клонови 347 и NS 73/6 беле врбе (Salix alba), поседују највећи енергетски потенцијал у поређењу са клоновима B-44 беле врбе и кошарачке врбе (S. viminalis)
Bioactivity of the Tree of Heaven Leaf Extracts Incorporated into Biopolymer Matrix Against Spongy Moth Larvae
No full textThe bioactivity of the Ailanthus altissima crude leaf extract (CLE) and a leaf extract
incorporated into a biopolymer matrix (BPM) was tested against Lymantria dispar larvae.
The crude leaf extracts and those incorporated into a chitosan–gelatin polymer matrix
were examined in choice and non-choice assays at 0.01, 0.05, 0.5, and 1% concentrations
for feeding deterrent activity, contact, and digestive toxicity. The CLE exhibited moderate
deterrent activity at all concentrations, whereas the BPM showed a very strong deterrent
effect at 0.5% and 1% and a strong effect at 0.1% and 0.01%. No significant differences in
digestive or contact toxicity were observed between the CLE and BPM groups and the
control groups. The BPM also influenced larval behavior after digestion, decreasing consumption and growth and increasing development time. The higher bioactivity of the CLE
compared to the control group is attributed to its high content of total phenols, flavonoids,
and tannins, whereas the enhanced bioactivity of the BPM is due to its incorporation into
the biopolymer matrix. Given its very strong deterrent activity, and absence of contact and
digestive toxicity, the BPM can be recommended as a potential environmentally friendly
bioproduct for forest pest control after field evaluation
Anthelmintic Activity of Winter Savory (Satureja montana L.) Essential Oil against Gastrointestinal Nematodes of Sheep
No full textBackground:
The increasing difficulties in combating anthelmintic resistance in gastrointestinal nematodes (GINs) of sheep worldwide, and the residues of chemical drugs in animal products and the environment, necessitate the search for alternatives. Previous studies have shown that plant essential oils (EOs) could be valuable anthelmintic agents, due to their numerous advantages. The present study aimed to evaluate the possibility of using winter savory (Satureja montana L.) EO against sheep GINs. The chemical composition of the tested oil was determined by gas chromatography-mass spectrometry (GC–MS). The efficacy of the tested oil was determined in vitro using the egg hatch test (EHT), and in vivo using the faecal egg count reduction test (FECRT) performed in two farms. Preliminary toxicity studies including clinical observation, haematological and biochemical blood analysis were also performed to evaluate the safety of the tested oil to the hosts. In addition, a coproculture study was carried out in the tested farms using the appropriate morphological keys.
Results:
Main compounds of the S. montana oil identified by GC–MS analysis were p-cymene (42.8%), carvacrol (28.1%) and y-terpinene (14.6%). The in vitro EHT showed a dose-dependent (R2 = 0.94) anthelmintic potential of the tested oil, with ovicidal activity varying from 17.0–83.3% and determined IC50 value of 0.59 mg/ml. The field efficacy reached 33% (at group level) and 50% (at individual level) at D14 after treatment. In vivo efficacy was significantly higher in farm 2 (FEC above 65% at group level, p 0.05) in the percentage representation of GIN genera were observed in the coproculture study, indicating that the treatment agent was not specific to a single genus.
Conclusion:
The anthelmintic potential showed on EHT and FECRT, without adverse effects on the sheep, suggests that S. montana EO is suitable for the control of sheep GINs as part of an integrated parasite management. However, further studies should be conducted to increase efficacy in field conditions
Declining productivity in two warbler species at CES site over a seven-year period
No full textThe Constant Effort Site (CES) Scheme was established in the UK in the late 1960s and adopted by 15 other European countries in the mid-1980s. The method involves using standardised, identical mist-nets at the same locations and times, set at regular intervals throughout the breeding season. It allows the monitoring of various common breeding bird species to assess the abundance, productivity and survival of these populations. In Serbia, the CES Scheme was introduced in 2018 at a single site in a reed bed. Our data, collected over seven years, using standardised CES method, includes five reed-breeding bird species: Moustached Warbler
(Acrocephalus melanopogon), Common Reed Warbler (Acrocephalus scirpaceus), Sedge Warbler (Acrocephalus schoenobaenus), Bearded Reedling (Panurus biarmicus) and Savi’s Warbler (Locustella luscinioides). The highest breeding success occurred in 2018, followed by a significant decrease in productivity in 2021. There is evidence of a decline in breeding adults between 2018 to 2021, possibly due to reduced adult survival in previous winters or during migration. Additionally, results indicate that two species —Common Reed Warbler and Sedge Warbler— produced fewer fledglings per breeding season, possibly due to adverse weather conditions (cold, rain) during the incubation period, repeated nesting or increased fledgling mortality. Additionally, research has
shown that low water levels in early spring hinder reed regeneration, limiting the availability of young shoots that certain warbler species require for nesting, which may contribute to their delayed reproduction
ELECTROSPUN SnO2 NANOFIBERS FOR ADVANCED GAS SENSING: FROM MORPHOLOGICAL DESIGN TO FUNCTIONAL PERFORMANCE
No full textThis work focuses on the fabrication of tin dioxide (SnO2) nanofibers using an electrospinning approach, aimed at producing nanostructured materials with potential gas-sensing applications. To enable the synthesis, an ethanol (EtOH)/dimethylformamide (DMF) solvent system was employed as the medium for precursor formulation. A polyvinylpyrrolidone (PVP) solution was prepared by dissolving PVP in the EtOH/DMF mixture under magnetic stirring, while, in parallel, tin(II) chloride dihydrate (SnCl2·2H2O) was dissolved in a separate portion of the same solvent system. The PVP solution was then added dropwise into the SnCl2 solution under continuous stirring, followed by thermal treatment in an oil bath at 45 °C for 2 h and cooling overnight. Electrospinning was performed under optimized conditions: an applied voltage of 20 kV, a needle-to-collector distance of 18 cm, a flow rate of 0.7 mL/h, and a collector rotation speed of 1000 rpm, using aluminum foil as the substrate. Nanofibers were collected over multiple electrospinning cycles, and after each cycle, the fiber-coated foils were dried to remove residual solvent. The dried nanofibers were then carefully removed and subjected to a specific thermal treatment regime, which included a final calcination step at 550 °C for 1 h to induce complete crystallization.
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). Thick films were fabricated by screen-printing a paste composed of calcined nanofibers dispersed in terpineol onto Al2O3 substrates pre-patterned with interdigitated electrodes and integrated microheaters. The printed films were subsequently heated at 160 °C for 1 h to remove the organic binder and improve adhesion between the sensing layer and the substrate.
The sensors were then evaluated for NO2 detection using a dynamic gas-sensing measurement system, in which the NO2 concentration was precisely regulated via mass flow controllers, with a total flow rate maintained at 100 mL/min. The sensing response was assessed across different NO2 concentrations and operating temperatures. The unique nanofibrous architecture and high surface area significantly enhanced sensing performance, revealing pronounced sensitivity and clear temperature dependence, thereby highlighting the material's strong potential for gas sensor applications.
The sensor processed from SnO2 nanofibers, with a specific surface area of 75 m²/g, a pore radius of 4.5 nm, and an average crystallite size of 15 nm, exhibited a superior sensor response (S = 367%) toward 20 ppm of NO2 at an operating temperature of 300 °C, suggesting it could be operative even at sub-ppm NO2 concentrations
Silicon enhances carbon bio-sequestration in wheat under elevated CO₂
No full textAtmospheric carbon dioxide (CO₂) is the most significant greenhouse gas contributing to global
warming. According to high-emission scenarios, CO₂ concentrations may exceed 1000 ppm by 2100 and rise above 2000 ppm by 2250. Carbon (C) occluded within phytoliths (PhytOC) is highly resistant to decomposition and can remain in soils for a long time. Since PhytOC originates from atmospheric CO₂ fixed through photosynthesis, it represents a potential long-term C sink. To investigate the C biosequestration potential of wheat, a hydroponic experiment was conducted under controlled environmental conditions. The study combined elevated CO₂ (eCO₂; 1000 ppm) with two silicon (Si) concentrations (0.5 mM and 1.5 mM H₄SiO₄), alongside a Si-free control. Parallel treatments were implemented at ambient CO₂ levels (aCO₂; approximately 400 ppm), using the same Si treatments. This experimental setup enabled assessment of the interactive effects of CO₂ enrichment and Si supply on wheat growth and its capacity for carbon stabilization via phytolith formation. At eCO₂, shoot dry biomass increased in all treatments, with the highest value (0.81 g plant⁻¹) recorded at 1.5 mM Si. Silicon supply enhanced total plant Si content across both CO₂ regimes. Silicon supply did not affect the maximum quantum efficiency of photosystem II (Fm/Fv) indicating undisturbed photosynthetic performance. However, C concentration in shoot tissue slightly decreased with higher Si, possibly due to a dilution effect or changes in C allocation. The combination of Si addition and elevated CO₂ concentration significantly increased phytolith formation and PhytOC accumulation in wheat, whereas no detectable phytoliths were found in plants grown without Si supply. However, the C concentration in phytoliths was lower in the 1.5 mM Si treatment than in the 0.5 mM Si treatment under both aCO₂ and eCO₂ conditions. The C/N ratio in phytoliths also decreased with increasing Si supply and was consistently lower under eCO₂ compared to aCO₂. Nevertheless, the highest PhytOC content (1.15 mg plant⁻¹) was observed at eCO₂ with 1.5 mM Si, approximately 50% more than in the same Si treatment at aCO₂. These findings indicate that Si supply at elevated CO₂ levels not only enhances Si accumulation and phytolith-based C sequestration but also promotes greater biomass production and physiological performance. This highlights the potential of Si fertilisation in climate-resilient crop cultivation and long-term atmospheric CO₂ mitigation