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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
Unlocking bioactive potential of peppermint seeds: fatty acids, phenolics, antioxidant and cytotoxic activity of supercritical CO2 extracts
No full textBACKGROUND: This is the first study aiming to investigate the yield and kinetics of supercritical CO2 extraction of peppermint (Mentha piperita L.) seeds, as well as to evaluate fatty acid and phenolic composition, antioxidant activity and cytotoxic properties against human lung adenocarcinoma (A549 cells) and normal fetal fibroblast (MRC-5 cells) of the obtained extracts. Applied conditions of pressure and temperature for extraction were in the range of 10–30 MPa and 40–50 °C. RESULTS: A significant increase in the yield was revealed at higher conditions of pressure and temperature. More than 80% of detected fatty acids belong to unsaturated fatty acids, with a predominant content of polyunsaturated fatty acids. With increasing pressure and temperature, the percentage of saturated and polyunsaturated fatty acids increased, whereas the amount of monounsaturated fatty acids decreased. The prenominal compounds in all tested samples were salvianolic acid, followed by rosmarinic acid and eriodictyol. Due to the highest content of individual phenolic compounds, optimal treatment for the phenolic compound extraction was 20 MPa and 40 °C. The sample extracted at the lowest pressure and the lowest temperature exhibited the most potent cytotoxicity against A549 cells. CONCLUSIONS: Peppermint seeds represent a high-value material that should be more extensively studied and encouraged for application in the food industry sector
Sustainable Reinforcement: Advancing Nanocellulose Modification for Biobased Unsaturated Polyester Resins
No full textIn this study, biocomposite materials were developed by reinforcing a biobased unsaturated polyester resin with cellulose nanofibers to meet the demand for sustainable, high-performance materials. The inherent hydrophilicity and abundant surface functionalities of nanocellulose pose challenges for integration with hydrophobic polymer matrices, such as unsaturated polyester resins. To address this, a purification-free, one-step modification method was introduced in which dimethyl itaconate acts simultaneously as an esterification agent and solvent. The resulting reaction mixture was used directly as a reactive diluent, eliminating hazardous solvents and additional purification steps. Incorporation of modified nanocellulose resulted in notable
performance enhancements, including a 23% increase in tensile strength at 0.3wt% of modified nanocellulose compared to the neat resin and elevated glass transition temperatures across all
samples. These findings emphasize the potential of the developed modification strategy to improve performance and sustainability, helping bridge the gap between sustainable polymer composites and their wider industrial application
Alkali-activated material: a sustainable approach for adsorbing heavy metals and rare earth elements from water
No full textThis study investigates the development of a geopolymer, synthesized by alkali-activation
of a ternary blend of fly ash, wood ash, and metakaolin, as a sustainable adsorbent for removing
heavy metal ions and rare earth elements (REEs) from water. Characterization of geopolymer surface
by Fourier transform infrared spectroscopy and scanning electron microscopy confirmed the
formation of an aluminosilicate polymeric network, and revealed a porous, heterogeneous surface
morphology favourable for adsorption. Adsorption experiments were conducted to evaluate the
removal efficiency of lead, zinc, and cadmium ions, and REEs (scandium, yttrium, and gadolinium)
under varying operational parameters. Pseudo-first order kinetics well described the adsorption of
cadmium and zinc ions, while the adsorption of lead ions and REEs follows the pseudo-second-order
model. Equilibrium adsorption data for heavy metal ions and selected REEs can be well described
by Langmuir isotherms, suggesting monolayer adsorption on a homogeneous surface.
Thermodynamic parameters indicated the exothermic adsorption of cadmium and zinc, and
endothermic adsorption of RREs and lead ions were spontaneous processes at temperatures higher
than 25 °C. The synthesized material demonstrates high adsorption capacity for metal ions,
underscoring the potential for reusing waste materials as a low-cost, sustainable alternative to
conventional adsorbents for wastewater treatment
The Technical Drawing Tools in the Legacy of Nikola Tesla
No full textThe legacy of Nikola Tesla contains numerous archival documents, monographic and serial publications, newspaper clippings, as well as personal and technical items. It includes thirteen specimens of technical drawing tools and some correspondence with the manufacturers. The tools were acquired and used by the famous scientist, engineer and inventor to produce technical documentation while designing and constructing numerous machines and devices in various areas of his creative efforts. The aim of this work is to analyze the original drawing tools preserved in the Nikola Tesla Museum in Belgrade, to inspect the corresponding catalogs, and to present a brief history of the relevant manufacturers
Multiple Synthesis Approaches for Terephthalic Acid-Modified g-C3N4 Photocatalysts for Efficient Cr(VI) Reduction
No full textEnvironmental pollution and energy shortages are two of the most pressing challenges humanity faces today. Photocatalysis is a cutting-edge approach to harnessing solar energy that holds significant promise for addressing these critical issues simultaneously [1]. Heavy metal contamination in the environment represents an important threat to life. Hexavalent chromium is considered one of the most toxic heavy metal ions because of its carcinogenic properties [2]. Recently, photocatalytic reduction of Cr(VI) is gaining popularity.
Graphitic carbon-nitride (g-C₃N₄) is a stable polymer photocatalyst activated by visible light, which possesses many promising properties. However, low specific surface area and high recombination rate still remain a challenge for the use of this material. Incorporation of aromatic rings in the network is an effective way to extend its π-conjugated system for visible light harvesting and to improve the charge transfer efficiency for prolonging the lifetime of photogenerated charge carriers in photocatalytic reactions [3]. One of the aromatic compounds used for modifying g-C₃N₄ is terephthalic acid.
In this work, the influence of different synthesis methods of terephthalic acid-modified g-C₃N₄ was investigated. Methods used for synthesis were thermal copolymerization and hydrothermal synthesis. Thermal copolymerization was conducted by heating the mixture obtained by grinding urea and terephthalic acid or by heating the mixture obtained by evaporation of ethanol from urea and terephthalic acid ethanol solution. Hydrothermal synthesis was conducted in teflon-lined autoclave filled with terephthalic acid solution and g-C₃N₄ prepared beforehand. The obtained photocatalysts were characterized by FE-SEM, EDS, XRD, DRS, and FTIR. The photocatalytic reduction of Cr(VI) was investigated under simulated solar irradiation, at pH 3, with citric acid as a hole scavenger. The photocatalytic efficiency of the modified samples were correlated with their structural and optical properties
Valorisation of pumpkin leaf by-product proteins through enzymatic modification in a biorefinery concept for meat emulsion application
No full textThe valorisation of agricultural and industrial side-streams within integrated biorefinery concepts is gaining increasing importance in the context of sustainable protein production and
the circular bioeconomy. In this context, waste green biomass is emerging as an alternative
protein source with potential applications in food formulations. This work investigated the
possibility of improving the techno-functional and antioxidant properties of protein isolated
from pumpkin leaves by partial enzymatic hydrolysis.
The white protein fraction, mainly composed of RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) was isolated from green juice obtained by pressing pumpkin leaves
through thermocoagulation, acid precipitation, subsequent resolubilisation and lyophilisation, and further treated with endopeptidase from Bacillus licheniformis in a stirred batch
reactor under the reported optimal conditions (pH 8, 55 °C). Enzymatic treatment at the optimal enzyme-to-substrate ratio (E/S = 6.5 wt.%, 75 min, degree hydrolysis ~ 15%) markedly
improved protein solubility, emulsifying capacity, interfacial functionality, and antioxidant
activity, supporting the potential application of pumpkin leaf protein as natural emulsifiers
and antioxidants in meat products
Circular Economy: Immobilization of Lactobacillus Acidophilus on Flaxseed Cake
No full textLactobacillus acidophilus has been increasingly studied as a probiotic for allergy treatment. For probiotics to deliver their beneficial effects, they need to be present in adequate numbers, which is often achieved by immobilizing them within protective matrices. A flaxseed cake is rich in fibers, proteins, and bioactive components, which makes it a potential good carrier for probiotics.
Flaxseed cake, obtained from the cold-pressed oils industry, was ground, sieved to a diameter of less than 600µm, sterilized, and diluted in distilled water at 10 % (w/v). After L. acidophilus inoculation, one sample was fermented, incubated at 4 °C for 1 h, frozen, and freeze-dried, while the other was subjected to every step but fermentation. The lyophilized probiotic powder was examined for probiotic viability and antioxidant capacity.
The probiotic culture showed a high survival rate in both samples. The fermentation decreased probiotic viability during the lyophilization procedure by 13 % but significantly increased the antioxidant activity of probiotic powder. The results indicate that flaxseed cake is a good probiotic carrier
Impact of carrier composition and probiotic metabolic activity on mechanical properties of extruded spheres
No full textIntroduction: Cold-pressed oil production is a rapidly expanding industry,
though it currently operates with low resource efficiency and generates
significant amounts of waste. Flaxseed cake, a byproduct of this process, is
notably rich in fiber, protein (~35%), and various bioactive or potentially
bioactive compounds. Due to its high fiber and protein content, flaxseed cake
holds promise as an effective carrier for probiotic immobilization - either on
its own or in combination with other materials such as alginate and pectin.
The strength of the support plays an important role in the production process. ..
Uticaj strukture pređe na prenos tečnosti kod glatkih pletenina
No full textLiquid transport is one of the most significant comfort-related properties of
textile fabrics intended for underwear and sportswear. To meet the wearer's
thermophysiological comfort, the textile fabric has to transmit and release sweat away from
the skin. The fabric's capability to transmit liquid sweat is affected by various factors,
including the structure of the yarn it is made from. Due to the limited results available in
the literature regarding the influence of yarn twist on the "liquid permeability" of textile
fabrics, this research aimed to investigate the effect of yarn twist on liquid transfer through
plain knitted fabrics. Additionally, the influence of moisture content in the fabric on the
liquid transport was investigated. Three plain weft knitted fabrics were produced from
three cotton yarns differing in twist. These knitted fabrics were subjected to the Malden
Mills water distribution test, with some modifications. The liquid transfer properties of the
knitted fabrics were evaluated using parameters - water transfer ability and water holding
capacity. The results obtained indicated that varying the yarn twists, which directly
influence the geometry and distribution of the complex pore system in knitted fabrics,
allows for effective design of the liquid transfer properties.Sposobnost prenosa tečnosti predstavlja jedno od najznačajnijih svojstava
komfora tekstilnih materijala namenjenih za izradu rublja i sportske odeće. Kako bi se
obezbedio termofiziološki komfor osobi koja nosi određeni odevni predmet, tekstilni
materijal treba da omogući nesmetani prenos i oslobađanje znoja sa površine kože.
Sposobnost tekstilnog materijala da prenosi tečni znoj uslovljena je nizom faktora
uključujući strukturu pređe od koje je materijal proizveden. Kako je u naučnoj literaturi
prisutan ograničen broj rezultata koji se odnose na uticaj upredenosti pređe na
propustljivost tečnosti kod tekstilnih materijala, cilj ovog istraživanja bio je ispitivanje
uticaja upredenosti pređe na prenos tečnosti kroz glatke DL pletenine. Pored toga, ispitivan
je uticaj sadržaja vlage u materijalu na sposobnost prenosa tečnosti. Tri različito upredene pamučne pređe upotrebljene su za izradu tri glatke DL pletenine. Ove pletenine su
podvrgnute Mallden Mills-ovom testu distribucije vode, uz određene modifikacije. Svojstva
upravljanja tečnošću ovih pletenina ocenjena su pomoću parametara – sposobnost prenosa
tečnosti i sposobnost zadržavanja tečnosti. Dobijeni rezultati su pokazali da se variranjem
upredenosti pređe, čime se direktno utiče na geometriju i distribuciju kompleksnog sistema
pora u pletenini, omogućuje efikasno projektovanje svojstava upravljanja tečnošću
pletenine