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Lignocellulosic Architecture and Bioconversion Potential of Arundo Donax and Zea Mays: A Fluorescence Approach
No full textArundo donax and Zea mays L. are increasingly recognized as valuable lignocellulosic
feedstocks for second-generation biofuels due to their high biomass yield, renewability, and
rich content of cellulose and hemicelluloses. While maize provides high digestibility and
methane yield per ton, giant reed thrives on marginal land with minimal inputs and offers
significantly higher biomass per hectare. However, its dense structure and higher lignin content
require more intensive pretreatment for effective bioconversion. The aim of this study was to
compare the structural properties of A. donax and Z. mays using fluorescence spectroscopy and
fluorescence-detected linear dichroism (FDLD) microscopy as complementary, non-destructive
methods. These techniques enabled detailed analysis of cell wall architecture and
lignocellulosic composition, providing insights into the distribution of wall components and
their response to pretreatment. In addition, mathematical modeling was applied to deconvolute
spectroscopic data and identify key structural features relevant to biomass conversion. The
results highlight distinct advantages of both crops in biogas production—Z. mays for higher
digestibility and A. donax for long-term sustainability—and underscore the importance of
structural characterization for optimizing biomass conversion efficiency. By integrating
fluorescence-based methodologies into biomass research, this work contributes to the
development of sustainable bioenergy strategies and advances the broader goals of the circular
economy
The contribution of organic agriculture to preservation and protection of genetic resources
No full textConservation genetics as an interdisciplinary scientific field has become almost compulsory in biodiversity preservation and in providing sustainable and successful farming, particularly in terms of global changes in climate and considerable increase in food demand. In Serbia, with the great potential of agroecology, organic cropping and breeding is a very useful approach to the preservation and protection of genetic resources. Organic agriculture, which disallows the application of any chemicals, including artificial manures and fertilisers, and which promotes natural procedures and processes, contributes to the preservation of plant and animal landraces that are commonly adjusted to specific local agroecological conditions. The present paper focuses on the performed studies related to organic farming, which significantly contributed to the conservation of genetic resources. This was done through the analyses of practices including the preservation of landraces (indigenous varieties), alternate cropping (crop rotation), the application of compost and green manure, and the prevention of the use of GMO technologies. Thanks to the application of these techniques, organic agriculture improves the soil fertility, decreases risk of the depletion of genetic resources, provides better resistance of flora and fauna to changes in climate. In comparison with the conventional production, putting organic farming into practice is confronted with many obstacles including higher investments, lower yields, technical and educational limitations. In order to cope with these problems, agricultural legislation has to be improved, education of farmers should be supported in order to motivate them to transfer from conventional to organic farming
Biowaste as a Resource: Challenges and Opportunities for Biowaste Management and Sustainable Infrastructure in Serbia
No full textBiowaste, as a renewable and biodegradable fraction of municipal solid waste, represents
about 40% of household waste in Serbia. Despite the availability of treatment technologies such as
composting and anaerobic digestion, most biowaste still ends up in landfills, contributing to methane
emissions and water pollution. This paper analyzes the management of biowaste in Serbia through
the lens of legislation and standards, comparing national regulations with the EU Waste Framework
Directive and examining the applicability of international standards (ISO 14001 and ISO 37101)
with the aim of improving waste management systems and supporting strategic infrastructure
planning. The study highlights the lack of separate collection systems, limited processing capacities,
and low public awareness regarding the potential of biowaste as a resource. The research applies a
theoretical approach based on qualitative analysis of legal documents, scientific literature, and
international standards. The aim is to define key principles for aligning biowaste management
practices with EU requirements and to propose recommendations for strengthening the legal and
technical framework, with particular emphasis on the role of standards in strategic planning of
sustainable infrastructure as a fundamental precondition for building the capacity of local
communities in implementing the concept of smart, sustainable, and resilient communities
Evaluation of Fermentation Effect on Antioxidants Amplification in Dandelion Root Extracts
No full textIntroduction: Fermentation is a process of partial decomposition of the fermented substrate due to the activity of various microorganisms involved. It is one of the most useful biocatalytic processes that may beneficially improve the bioactivity of plant extracts. Accordingly, this study investigates the fermentation effects of underutilized dandelion root dust (Taraxacum officinale L.) on phenolic content and antioxidant activity potential in the produced extracts. The dandelion root was collected as dust remaining after the processing for the industrial tea blends preparation, thus is classified as a second-rank raw material, possessing low or no commercial value. Regarding the fermentation effects, the focus was on the contributions of various microorganisms, including the yeasts Saccharomyces cerevisiae and Saccharomyces cerevisiae var. boulardii, a yeast-like fungus Aerobasidium pullulans, and lactic acid bacteria (LAB) Lactobacillus rhamnosus ATCC® 7469™. Experimental: Fermentation is a process of partial decomposition of the fermented substrate due to the activity of various microorganisms involved. It is one of the most useful biocatalytic processes that may beneficially improve the bioactivity of plant extracts. Accordingly, this study investigates the fermentation effects of underutilized dandelion root dust (Taraxacum officinale L.) on phenolic content and antioxidant activity potential in the produced extracts. The dandelion root was collected as dust remaining after the processing for the industrial tea blends preparation, thus is classified as a second-rank raw material, possessing low or no commercial value. Regarding the fermentation effects, the focus was on the contributions of various microorganisms, including the yeasts Saccharomyces cerevisiae and Saccharomyces cerevisiae var. boulardii, a yeast-like fungus Aerobasidium pullulans, and lactic acid bacteria (LAB) Lactobacillus rhamnosus ATCC® 7469™. Results: During the fermentation of dandelion root, a single yeast culture demonstrated the highest efficiency in enhancing the levels of antioxidants in the resulting extracts, significantly outperforming the control sample. Specifically, the probiotic yeast S. boulardii induced a substantial increase in TPC, with a 2.5-fold rise to 68.4 mg GAE/g dm. Additionally, TFC levels increased 2.8 times, reaching 44.9 mg QE/g dm, while the FRAP showed a 3.9-fold increase, totalling 417.2 μmol Fe2+/g dm, when compared to the control. Following S. boulardii, S. cerevisiae emerged as the next most effective yeast for dandelion root fermentation. A combination of L. rhamnosus and S. cerevisiae also showed good performance, although the fermentation with L. rhamnosus alone led to only a negligible increase in the content of bioactive compounds and antioxidant activity. The results of this study are valuable in promoting the value-added fermentation effect in the utilization of dandelion root extracts as supplements in food and pharmaceuticals that offer enhanced health benefits. The approach taps into readily available industrial residues to be creatively exploited in useful and profitable ways
Fish as bioindicators of reservoir pollution
No full textIn this study we investigated the bioindication potential of the European perch (Perca fluviatilis) [1,2,3], European chub (Squalius cephalus) [4], and common roach (Rutilus rutilus) from reservoirs in Serbia with different anthropogenic influences and uses: water supply (Garaši) and power generation (Vlasina, Perućac, Zaovine, and Međuvršje). We determined the concentrations of 26 elements - PTEs (Ag, Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Se, Si, Sr, and Zn) in the muscle, gills, and liver using inductively coupled plasma optical emission spectrometry (ICP-OES), and 17 organochlorine pesticides – OCPs (Aldrin, α-HCH, β-HCH, γ-HCH, δ-HCH, 4.4′-DDD, 4.4′-DDE, 4.4′-DDT, Dieldrin, Endosulfan I, Endosulfan II, Endosulfan sulfate, Endrin, Endrin aldehyde, Heptachlor, Heptachlor epoxide, and Methoxychlor) in muscle using gas chromatography–mass spectrometry (GC-MS). These results were compared with histopathological (HP) analyses in gill and liver, and the potential health risks to humans from the consumption of fish meat were assessed. The target hazard quotient (THQ) and target cancer risk factor (TR) are used to calculate the human health risk associated with the non-carcinogenic and carcinogenic contaminants, respectively [7]. The results showed that the accumulation of PTEs varied by reservoir, species and tissue. Reservoirs used for power generation were under the highest anthropogenic pressure, and those at lower elevations were more polluted compared to reservoirs at higher elevations. Chub and roach were not good indicators of Pb pollution. In addition, roach were not good indicators of Cd and Cr pollution. The muscle tissue of all species showed the lowest metal contamination, while the highest was found in the gills. The concentrations of 14 OCPs were below the detection limit in all studied reservoirs. Heptachlor, 4.4′-DDD and 4.4′-DDE were seldom detected in the sampled fish. In all species, low to moderate HP alterations were detected in both the gills and the liver, which were not due to the accumulation of PTEs in these tissues. The concentrations of As, Cu, Pb, Zn, 4.4′-DDD, 4.4′-DDE, 4.4′-DDT, heptachlor, and heptachlor epoxide were below the maximum allowable concentrations in food [5,6]. The THQ and TR values showed a low and acceptable risk to consumers. The reservoir designated as a drinking water source can be considered the safest in terms of fish consumption
Computational microscopy with the PERCIVAL detector 6 system at TwinMic beamline
No full textPERCIVAL is a novel soft X-ray detection system designed for the needs of modern
microscopy. By integrating it into the TwinMic end-station at Elettra Sincrotrone Trieste, we conducted
an exploratory computational microscopy experiment on biological samples, aiming at evaluating
the entire system in a real use-case scenario. We present the methodology to convert the RAW data
and our high-resolution image reconstructions
Durable Composite Ni-MoOx Catalysts Electrodeposited on High Surface Nickel Substrates for Low-Cost Green Hydrogen Production
No full textThe growing number of systems using fuel cells instead of internal combustion engines has increased the need for sustainable green hydrogen production. The high cost of catalysts for hydrogen evolution reaction (HER) has been considered as a significant challenge addressed by the novel Ni-MoOx catalyst developed in this study. Unlike commercially used platinum-group metals, the proposed composite coating consisted of earth-abundant elements, with the key innovation being the synthesis of a powder composed of MoO2.8, H2MoO4, MoO3, MoO2 and (NH4)2Mo2O7, that was confirmed by XRD analysis. The electrodeposition was carried out under severe hydrodynamic conditions and optimized to ensure that the coating composition on both substrates (Ni foam and Ni mesh) was identical. XPS analysis revealed that Mo6+ and Ni2+ species were placed on the surface, while Mo4+, Mo5+ and Ni0 were detected deeper within the coating.
The electrocatalytic performance of Ni-MoOx composite catalyst for HER was evaluated in 30 wt.%
KOH at 70˚C, with the lowest overpotential at j = -1000 mA cm-2 being only -86 mV for the coating
electrodeposited on Ni foam. To ensure a realistic comparison with industry standards, stability tests were performed on the coating electrodeposited on Ni mesh, commonly used substrates by De Nora for their HER catalysts. The procedure, obtained directly from De Nora, simulated five years of real-world operating conditions. The results showed that the electrode investigated in this study was more stable than commercially available ones, and exhibited nearly identical activity after five years of operation, if compared to a new commercial electrode (Figure 1). The amorphous structure of the Ni-MoOx coatings electrodeposited on both Ni foam and Ni mesh was confirmed by SAED analysis.
A modified approach to Electrochemical Impedance Spectroscopy (EIS) analysis, based on Nyquist plots, determined the exchange current densities for charge transfer (j0,ct), intermediate adsorption (j0,ads), and overall HER (j0.tot). These results revealed that any of the partial reactions could be the rate-determining step, providing deeper insight into the catalytic mechanism of the Ni-MoOx composite catalysts
Synthesis and Characterization of Cross-linked Poly(N-(2-hydroxyethyl)acrylamide)
No full textThe monomer N-(2-hydroxyethyl)acrylamide is used in many investigations for the synthesis of various copolymers, e.g. block- or graft- copolymers. Polymers based on this monomer have been widely investigated, e.g. as capillary adsorbed coatings, for stimuli-sensitive polymer synthesis, in bioengineering research, for adhesive hydrogels. They have good biocompatibility, stability and durability. This study describes the process of the synthesis of homopolymer hydrogels based on monomer N-(2-hydroxyethyl) acrylamide by the free radical polymerisation method with thermal initiation using 1,2-ethanediol dimethacrylate as a crosslinker. The polymerization process was initiated by 2,2‘-azobis(2-methylpropionamidine) dihydrochloride. The cross-linked homopolymer poly(N-(2-hydroxyethyl)acrylamide) hydrogels were structurally characterized after the purification of unreacted reactants. Structure characterization of the obtained homopolymer was performed using the Fourier transform infrared spectroscopy (FTIR). Analysis of the obtained FTIR spectra confirmed that the polymerization process was successfully completed, by breaking the double bonds from the N-(2-hydroxyethyl) acrylamide and the 1,2-ethanediol dimethacrylate, which resulted in the formation of a new crosslinked homopolymer products. Hydration capacity of synthesised homopolymer hydrogels was examined in the function of pH values and temperatures. Based on the obtained results, these homopolymer hydrogels show great potential for further research opportunitiesand new applications
TEXTILE DYES REMOVAL USING HYDROTHERMALLY SYNTHESIZED LiTiO2
No full textEnvironmentally friendly titanium-based nanomaterials, such as layered
titanates, are increasingly used in nanotechnology due to their excellent properties in
the fields of metal-ion batteries, adsorption, photocatalysis, and sensors [1,2]. In
order to obtain a pure LiTiO2, nanoanatase powder was hydrothermally treated with
3 M LiOH solution at 120 °C for 18 h. The sample was characterized by XRPD,
SEM, TG/DTA, and UV-VIS/DRS analyses. XRPD confirmed the complete
transformation of the starting nanoanatase into the pure LiTiO2 phase with the
average crystallite size around 17 nm. According to SEM, LiTiO2 nanoparticles of
about 40 nm created very soft agglomerates of 2–5 μm size. The thermal stability of
the obtained lithium titanate was confirmed by TG/DTA up to 400 °C. The
adsorption capacity and photocatalytic activity of the LiTiO2 nanopowder were
tested on harmful industrial dyes. The LiTiO2 nanoparticles completely adsorbed the
Ethyl Violet dye within 5 min and 53.2 % of the Methylene Blue dye within 30 min.
On the contrary, the same sample negligibly adsorbed the Mordant Blue 9 dye, but it
photodegraded 66.2 % of this dye within 4 hours under simulated solar light. The
strong adsorption power and photocatalytic activity of LiTiO2 open the possibility of
its multipurpose application in wastewater treatment.
1. B. Simović, A. Dapčević, J. Zdravković, N. Tasić, S. Kovač, J. Krstić, G. Branković,
J. Alloys Compd., 781 (2019) 810.
2. H.-D. Yang, Y.-Y. Kang, P.-P. Zhu, Q.-W. Chen, L. Yang, J.-P. Zhou, J. Alloys
Compd., 872 (2021) 159759
Middle Miocene syn-rift sequence on the central Gulf of Suez, Egypt: Depositional environment, diagenesis, and their roles in reservoir quality
No full textThe middle Miocene sediments, a key oil reservoir within the syn-rift structures of the Gulf of Suez, have received limited research attention despite their geological importance. To bridge this gap, we analyzed well cores and petrophysical data from the middle Miocene sandstone-shale sequence (Sidri Member) in the Belayim field, one of Egypt’s major oil fields, to assess the depositional and diagenetic characteristics and evaluate reservoir quality. It is subdivided into three sandstone units separated by calcareous shale interbeds. The units show distinct lateral and vertical distribution, reflecting an upward change in depositional environment, transitioning from shoreface, deltaic condition, to embayment settings, interrupted by shale deposition during transgression episodes. The sediments originated from uplifted and tilted rift margins along NW-SE trending faults. During the syn- to post-rift burial to depths exceeding 2.5 km, diagenetic processes, including compaction, dissolution, and cementation, altered the sandstones’ primary properties, resulting in significant petrophysical variations. Porosity reaches up to 30% in well-sorted, medium-grained sandstones with dissolution, corresponding to bulk density as low as 2.1 g/cm3 and permeability up to 1000 mD, while cementation reduced porosity in certain intervals, creating heterogeneity in grain density and permeability. Reservoir quality of the sandstones ranges from poor to excellent with variable oil saturation. Notably, the lower sandstone unit, located within an anticline structure, displays good to excellent quality and up to 70% oil saturation. These findings highlight the influences of syn-rift dynamics in shaping the middle Miocene sequence and the potential for optimizing hydrocarbon exploration and production strategies across the region