The aim of the study was to determine how the temperature and gaseous environment of annealing affect the morphological and luminescent properties of nanostructured zinc oxide (Zn) -based materials. The study was carried out in Ukraine at the National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute". The methodology included chemical deposition from aqueous solutions followed by thermal annealing at 300, 500, and 700 °C in air, nitrogen, and argon. The morphology was analysed by scanning electron microscopy (SEM), the crystal structure by X-ray diffraction (XRD), and the luminescence spectra by photoluminescence (PL) spectroscopy. The results showed an increase in particle size with increasing temperature, regardless of the atmosphere, with a minimum (~45 nm) at 300 °C in argon and a maximum (~112 nm) at 700 °C in air. With increasing temperature, the coverage density decreased, especially under inert conditions, due to nanoparticle aggregation. Correlation analysis showed a strong negative relationship between particle size and emission intensity (r=-0.89) and a positive correlation between coverage density and PL brightness (r=0.76). Thus, it was established that high-temperature annealing in an oxygen atmosphere most effectively improves the luminescent characteristics of ZnO for optoelectronic and sensor applications. The results are of practical significance for the development of high-efficiency optoelectronic and sensing devices.
Sustainable development in modern industry is crucial for balancing environmental, economic, and social factors. This is a key challenge for Ukraine, which must adapt international sustainable practices and integrate Industry 4.0 and 5.0 principles into its production processes. A study analyzes sustainable development in the Ukrainian industry, identifying barriers and opportunities through a mix of quantitative data from the EU, the U.S., and Ukraine, and a qualitative review of academic publications. The findings show significant progress between 2020 and 2024. The food, metallurgy, and machine-building sectors experienced a considerable decrease in energy intensity (18.9-22.6%) and CO2 emissions (15.7-23%). Waste recycling also increased by 13-18%. Economically and socially, these sectors experienced a 17-20% rise in labor productivity and new job creation, demonstrating the positive "multiplier effect" of sustainable practices. Digital technologies like digital twins and augmented reality were found to be key drivers of this transformation. The study concludes by emphasizing the importance of adaptive leadership and employee training. The findings offer practical guidance for enterprise strategies and government programs, though further research is needed to fully understand long-term impacts.
The aim of the study was to evaluate the effectiveness of applying robotics for automating livestock feeding and farm management in Ukraine. The methodology was based on a comprehensive approach combining time recording, energy auditing, and economic analysis methods at four agricultural enterprises in the Kyiv, Cherkasy, Vinnytsia, and Poltava regions. Computer modelling (MATLAB Simulink), biosensor monitoring of animals, and advanced statistical methods (GPower, Shapiro-Wilk criterion) were used. The study found that the introduction of robotic feeding systems increased the accuracy of feed component dosing by 20.7%, feed mixing uniformity by 24.8%, reduced energy costs by 53.9%, and increased animal productivity by 12.3-13.7%. The economic feasibility is confirmed by an average payback period of 4.3 years with an internal rate of return of 27.5%, a return on investment of 34.7%, and a profitability index of 1.85. It has been determined that the most cost-effective solution is to introduce robotic systems on farms with a livestock population of 100 to 150 heads, where the use of suspended rail systems provides the best ratio of investment costs to economic benefit. The results of the study are of direct practical importance for the modernisation of livestock farms in Ukraine and can be used as a basis for the development of state programmes to support technological modernisation in the agricultural sector.
This study investigates the influence of controlled preload magnitude and duration on the mechanical properties of 15 tex viscose yarn. A central composite experimental design was used to examine how preload parameters (preload magnitude and duration) affect the breaking force, tenacity, and breaking elongation of the yarn. The results show that preload magnitude is the dominant factor governing yarn behavior, whereas preload duration has only a minor effect. Moderate intermediate preloading (preload magnitude, Fn = 84.8 cN/thread, for a preload duration of Tn = 2.0 hours) increased the yarn's breaking force and tenacity by approximately 30-34% compared with the unloaded state. This improvement is attributed to increased fiber alignment and structural consolidation within the yarn. However, the enhanced mechanical properties were accompanied by a reduction of approximately 24% in breaking elongation, indicating decreased extensibility. These findings demonstrate that preload application can be used as a practical process parameter to tailor yarn performance for textile applications, particularly where higher mechanical properties are required, such as in knitting. The outcomes provide useful guidance for optimizing yarn preparation and improving the mechanical reliability of viscose-based textile products.
The aim of the study was to investigate the effectiveness of innovative technologies in creating three categories of low-calorie foods based on plant raw materials: meat substitutes, dairy analogues, and bakery products. The study conducted a comparative assessment of the nutrient composition, energy value, glycaemic response, organoleptic characteristics, technological stability, and cost of products manufactured using traditional and innovative approaches. The experiment involved the combined use of wet extrusion, ultrasonic treatment, controlled fermentation, pulsed electric field (PEF) processing, enzymatic hydrolysis, and functional ingredients such as amaranth, inulin, psyllium, soy, and pea isolates. It was found that innovative meat substitutes had a reduced energy value (145 kcal/100 g), high protein concentration (22 g/100 g), and increased texture elasticity by 31%. All samples remained microbiologically safe for 9-12 days. Sensory evaluation showed high consumer acceptance: the average score on the expert scale was between 4.3 and 4.6. Statistical analysis of the results confirmed the reliability of the differences between traditional and experimental products (p<0.05). The cost of producing innovative products increased by 8-13% depending on the category, but due to improved functional characteristics and shelf life, the products have high potential for industrial implementation in the functional, preventive, and dietary nutrition segment.
Wall germander (Teucrium chamaedrys L., Lamiaceae) is an aromatic medicinal plant widely used in folk medicine. Beyond its ethnopharmacological value, it tends to accumulate specific minerals selectively. Consequently, rigorous quality control of its products is essential before they are placed on the market. Monitoring the presence of heavy metals is particularly critical, as these elements can accumulate in human and animal tissues, leading to significant health issues. The goal of the present study was to determine the elemental composition (K, Ca, P , S, Mg, Na, Si, Cu, Zn, Sr, Ba, Fe, Li, Mn, Bi, Ag, B, CE, Cr, Co, Ni, As, Cd, Pb, Tl, and Hg) of wall germander aqueous extracts. These extracts were produced from both the aerial part (herb) and the herbal dust (a by-product of tea processing). Ultrasound-assisted extraction was employed under the following next conditions: distilled water as the solvent, a constant temperature of 50 °C, a liquid-to-solid ratio of 15 mL/g, and an ultrasonic power of 150 W, with varying time intervals (10, 20, and 30 min). Following wet digestion, the elemental concentrations (expressed in mg/L) were evaluated using Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). All extracts exhibited high concentrations of K, followed by P and Ca. The results indicated that aqueous extracts from both the herb and herbal dust obtained after 20 minutes contained the highest mineral content, suggesting that this extraction duration is the most efficient and suitable for producing extracts intended for human consumption.
Siloxanes represent polymers that can occur in several forms, enabling the production of materials with diverse structures. The proportion of organic and inorganic precursor units influences a wide range of siloxane polymer modifications. The immiscibility of different phases leads to microphase separation, which can be mitigated by improving component miscibility through chemical bonding or enhanced physical interactions. In this study, a reactive siloxane polymer containing vinyl groups and silicon(IV) oxide as a reinforcing filler was used to prepare a masterbatch for the crosslinking of liquid silicone rubbers (LSR). The masterbatch was incorporated at concentrations of up to 10 wt% in formulations with varying hydrogen siloxane to vinyl siloxane (H:Vi) ratios (40:60, 50:50, and 65:35). The crosslinking reaction was confirmed by FTIR spectroscopy, while TEM analysis revealed good dispersion of the filler within the polymer matrix. The results showed that the 50:50 H:Vi ratio with 5% masterbatch exhibited the most balanced mechanical properties, achieving a tensile strength of 10.00 MPa and a Shore A hardness of 54. However, FTIR analysis demonstrated that masterbatch addition had a dose-dependent inhibitory effect on crosslinking efficiency, which decreased from 97.0% (in the unfilled 50:50 sample) to 91.4% with 10% masterbatch. TGA analysis revealed that the 65:35 ratio with 10% masterbatch exhibited the highest thermal stability (Tons = 455 °C). The findings suggest that masterbatch composition can be tailored to achieve specific material properties, but its impact on crosslinking kinetics must be considered during formulation design.
Increased presence of chromium in water resources represents a significant environmental and public health concern due to its high mobility, toxicity, and carcinogenic nature. Biosorption using microbial biomass has emerged as a sustainable alternative to conventional physicochemical treatment methods. In this study, the biosorptive potential of dead Pichia kluyveri K-1 biomass was investigated for the first time for chromium removal from aqueous solutions. Process optimization was performed using response surface methodology based on a Box-Behnken experimental design evaluating the effects of solution pH (2-7), initial chromium concentration (20-100 mg/L), and biosorbent dosage (2-10 g/L). Chromium removal efficiency ranged from 7.8% to 42.0%, while final chromium concentrations after biosorption varied between 11.6 and 88.5 mg/L depending on process conditions. Lower initial chromium concentrations and a strongly acidic environment resulted in substantially reduced residual chromium levels, indicating improved biosorption performance under conditions favoring protonation of biomass surface functional groups. Analysis of variance showed that the initial chromium concentration was the dominant factor governing final chromium concentration, whereas pH had the strongest influence on removal efficiency. Response surface analysis confirmed significant nonlinear effects and identified optimal operating conditions at pH 2, an initial chromium concentration of 20 mg/L, and a moderate biosorbent dosage. Under these conditions, predicted removal efficiency was 42.8%, which was also confirmed experimentally. These findings provide a foundation for further optimization and biomass modification for water treatment applications using novel, environmentally safe biosorbents.
Biomass combustion waste ash, such as wood ash, represents a promising low-cost raw material for the biodiesel industry, as it predominantly consists of alkali and alkaline earth metal oxides. In this study, biodiesel production from sunflower oil via methanolysis was investigated using waste wood ash as a catalyst. This is the first study to integrate detailed physicochemical characterization, catalytic performance evaluation, and a preliminary economic assessment for the valorization of waste wood ash as a catalyst in sunflower oil methanolysis. The catalyst was comprehensively characterized to determine its thermal behavior, chemical and phase composition, textural properties, morphology, and base strength. The catalyst composition indicated Ca (43 wt.%) and K (18 wt.%) as the major elements, consistent with the XRD results, which identified their oxides as dominant phases. The catalytic performance of wood ash was evaluated under atmospheric pressure in batch mode. The influence of catalyst loading (5-15 wt.%, based on the oil mass) and methanol-to-oil molar ratio (9:1-15:1) on the fatty acid methyl esters (FAMEs) content was investigated at a reaction temperature of 60 °C. The rapid conversion of triacylglycerol (TAG) into FAME was observed, indicating negligible TAG mass transfer limitations. Increasing catalyst loading significantly enhanced FAME formation with 15 wt.% as the optimal value within the investigated range. While the methanol-to-oil molar ratio had a slight positive effect on the final FAME content, higher ratios reduced the reaction time required to achieve FAME contents above 95% from 40 to 20 min at the highest catalyst loading. Despite the high feedstock cost indicated by preliminary cost analysis, the results demonstrated that waste wood ash is an effective low-cost catalyst for biodiesel production, although its catalytic activity is limited to a single reaction cycle.
Hemp (Cannabis sativa L.) is a versatile crop used across multiple industries, and its seed oil has potential application as a renewable raw material for biodiesel production. This study investigates the kinetics of biodiesel production via quicklime-catalyzed methanolysis of hemp seed oil (HSO). Owing to the moderately high concentration of free fatty acids, HSO was first subjected to esterification. The methanolysis of the esterified HSO was performed at methanol-to-HSO molar ratios of 6:1, 9:1, and 12:1, with quicklime amounts of 3%, 5%, and 7% of HSO mass, at 60 oC under atmospheric pressure. The kinetics of the methanolysis reaction was evaluated using two different kinetic models: a pseudo-first order model and a model involving a changing reaction mechanism coupled with triacylglycerol (TAG) mass transfer limitations. The pseudo-first order model effectively described the reaction kinetics within two distinct regimes, initially controlled by TAG mass transfer, followed by a chemical reaction-controlled regime. The second model provided a continuous description of the reaction kinetics over the whole reaction course. The volumetric TAG mass transfer coefficient and the parameter defining the affinity of TAG to the active sites of the catalyst were found to be independent of methanol concentration but increased with catalyst amount. Both models yielded the same apparent reaction rate constant (0.155 min-1) and demonstrated very good agreement with experimental TAG conversion degree data (MRPD = ±10.8%, 81 data points). Despite comparable accuracy, the model involving the changing reaction mechanism and TAG mass transfer limitations is recommended due to its computational simplicity and consistent applicability.
The pedunculate oak (Quercus robur L.) is rich in extractives, especially in its heartwood, stumps, and bark, making it valuable to bio-based industries. Due to this reason and the increasing demand for efficient wood utilization, this study investigated the extractives of stumps remaining after freshly cut trees and Q. robur trees cut two years prior. During these two years, the stumps were exposed to various weather conditions (precipitation, UV radiation, and others) and the action of fungi, bacteria, and other pathogenic organisms. These factors contributed to the natural degradation of the wood and the disruption of the original chemical structure of the stumps. Water extracts from the xylem and bark of freshly cut and biodegraded Q. robur stumps were analyzed for total phenols, activity against H2O2, and free radical scavenging activity. Total phenol content was higher in degrading Q. robur stumps, with 71.70 and 59.17 mg gallic acid equivalents/g dry wood in bark and xylem, respectively. Degrading Q. robur stump bark and xylem showed higher antioxidant activity, with IC50 values against H2O2 of 682.39 µg/mL and 923.90 µg/mL, and free radical scavenging activity of 91.97% and 83.98%, respectively. High-performance thin-layer chromatography fingerprinting profile of xylem and bark extracts revealed different chemical profiles, while the HPTLC-DPPH scavenging assay evaluated antioxidant activity in extracts. This research showed that extracts from the bark and xylem of the degrading stump are stronger radical scavengers and have a richer phenolic profile than extracts from a freshly cut stump. Degrading Q. robur stumps may represent a valuable source of polyphenols.
This research paper describes the utilization of experimental measurement and an information system based on an ATmega328P microcontroller and a 16-bit A/D converter for application in the process of measuring and determining the pH value and temperature of the grape must during wine production. The system also contains a WiFi module enabling the measurement values to be monitored wirelessly via a local WiFi network or the Internet. Measurement of the pH value and temperature of grape must represents the basic steps in wine production. During the wine fermentation process, the pH value changes, while the temperature is maintained at 16 degrees, and this process was monitored in the wine cellar of the agricultural farm Milosavljević in Svrljig, Serbia. In addition to the proposed system, a professional pH meter was used as a reference measuring device, Eutech CyberScan pH 510, which was calibrated in a national laboratory. Measurements over the period of 10 days are presented. A comparison of the obtained measurement results with those obtained from a professional pH meter is also presented.
This study introduces a novel comparative analysis of three commercially produced flax-based yarn types - cotton/flax (70/30), PAN/flax (70/30), and pure flax - with a focus on breaking force and breaking elongation under varying preload magnitudes and durations. The preload magnitude was expressed as a percentage of the breaking force for each yarn type and ranged from 10% to 50%. The preload duration was between 0.5 and 3.5 hours for all types of yarn. The results demonstrate that yarn behavior is strongly influenced by raw material composition. Cotton/flax and PAN/flax yarns exhibited structural stability under different preloading conditions, with minimal variations in breaking force (1-2%) and breaking elongation (1-2% for PAN/flax), whereas pure flax yarn showed higher sensitivity, particularly to preload magnitude, with changes of up to 10-11% in elongation. Preloading reduced breaking force and elongation across all yarns, with the most pronounced reductions observed for blended yarns. PAN/flax yarn consistently achieved the highest breaking elongation, approximately three times that of cotton/flax yarn, highlighting the reinforcing effect of PAN fibers. Breaking time was largely unaffected in cotton/flax and flax yarns, but PAN/flax yarn exhibited a decrease of up to 10% with increasing preload magnitude. These findings emphasize the critical role of fiber composition and preloading conditions in optimizing yarn performance, reducing breakage, and improving knitting efficiency.
This study aimed to evaluate and compare the mechanical properties of Glass ionomer cement (GIC) modified with varying concentrations of Zirconia nanotubes (ZNTs). Different proportions (0.5%, 1.0%, 2.0%, 5.0% by weight) of ZNTs were added to the GIC powder to prepare a total of 200 specimens, divided into five groups of 40 specimens according to modifications. The eight specimens from each group (n=8) were allocated for testing each mechanical property. The mechanical properties investigated were compressive strength (CS), diametral tensile strength (DTS), flexural strength (FS), shear bond strength (SBS), and microhardness. CS, DTS, FS, and SBS were measured using the universal testing machine, while microhardness was assessed using a Vickers hardness tester. The GIC modified with 0.5 Wt% ZNTs exhibited the highest CS, DTS, and FS values. The highest Vickers hardness was observed with the 1.0 Wt% ZNTs group. However, all ZNT-modified groups showed lower SBS values compared to the control group. The findings suggest that incorporating 0.5 Wt% % ZNTs significantly enhances the CS, DTS, and FS of GIC, while 1.0 Wt% ZNTs improves microhardness. However, ZNTs' incorporation negatively affects the SBS.
Every year, more than 5 million end-of-life vehicles (ELVs) in Europe must be properly managed, otherwise, inadequate handling will result in environmental pollution. From an economic perspective, approximately 6 million tonnes of valuable materials are lost annually through ELVs. Platinum (Pt), palladium (Pd), and rhodium (Rh) belong to the platinum-group metals (PGMs) and represent an active component of automotive catalytic converters, which are used for the efficient catalytic conversion of exhaust gases into less harmful compounds. The automotive industry is one of the most resource-intensive sectors. As the number of motor vehicles increases, the global demand for the mentioned precious metals is constant, as they are also listed among the critical ones. Moreover, the PGMs are also required in green technologies related to vehicle electrification, green energy, hydrogen production, etc. Due to their high PGM loadings, spent automotive converters are valuable secondary materials that could be exploited at lower prices and with less ecological impact on the environment compared to the extraction of PGMs from ores. Numerous agents are proposed in the literature for the leaching of PGMs, among which cost-effective, environmentally friendly, and sustainable leaching solutions are preferable. The article aims to emphasise the importance of recycling PGMs from secondary raw materials, primarily spent automotive catalytic converters (ACCs), and to provide an overview of the key aspects of the current supply and demand challenges related to PGMs.
The yield and chemical composition of cow's milk, and consequently the quality of raw milk and its derived products, exhibit significant seasonal variations. These oscillations are largely influenced by factors such as feeding practices and seasonal variations. In recent years, climate changes, including mild winters and hot summers, have increasingly contributed to these fluctuations. This study examined the effects of seasonal transitions, specifically between summer and winter, on key biochemical parameters and physical properties of milk produced in the Nišava and Pirot districts of Southern Serbia. The research analyzed bulk milk samples collected from the "Milk House" dairy in Niš, sourced from nine collection points, primarily from individual households. The average daily milk quantity per collection site was approximately 300 l. Samples, each 0.5 l in volume, were collected daily from January to March and from June to August 2024, ensuring a comprehensive comparison of seasonal effects. Laboratory analyses at the dairy focused on biochemical components such as protein, fat, lactose, and minerals, as well as physical properties like density and pH. For all parameters, average values were calculated for the specified periods. The results provide insights into milk composition changes driven by seasonal factors, which have significant implications for the quality of final dairy products. Moreover, these findings underscore the necessity of adapting processing technologies to align with seasonal variations in raw milk properties.
The use of spices and medicinal plants in human nutrition has been increasing recently. They have numerous benefits due to their antioxidant and antimicrobial properties, and they are particularly important in the prevention of microbial transmission. Nevertheless, they may also contain environmental pollutants that are introduced during manufacturing, processing, and storage. Spices and medicinal herbs can become contaminated throughout the manufacturing and packaging process, as well as during the cultivation of plant species. The greatest danger comes from heavy metals, which enter plants through soil, air, and water. The operation of various industrial facilities results in contamination. This paper will discuss heavy metals, both essential and non-essential, and their effects on human health. Copper, zinc, manganese, iron, molybdenum, chromium, and selenium are essential, whereas lead, mercury, cadmium, arsenic, aluminum, tin, cobalt, and platinum are non-essential.
Ajvar is a pepper-based relish that represents a mixture of roasted sweet peppers. As a domestic agricultural food product known as vegetable caviar, ajvar is consumed in small portions, cold, in addition to the main meal, or as a spread. This paper investigated the composition of domestic ajvar made of Capsicum annuum L. sweet peppers. Bioactive compounds, mineral matters, moisture, ash, crude protein, and total fat content were analyzed. The identification of bioactive compounds is done using the UHPLC-DAD-ESI-MS/MS method. The content of mineral matters, in the ajvar sample, has been investigated by ICP-OES. Moisture and ash content are determined by using gravimetric methods, while the Kjeldahl method and Soxhlet extraction were used for crude proteins and total fats content determination, respectively. Out of the bioactive compounds several organic acids and flavonoid derivates were successfully identified in the ajvar sample. Investigation of mineral compositions showed high levels of sodium (3571.703 mg/kg) and potassium (2172.695 mg/kg), as well as the presence of some significant microelements such as zinc (10.740 mg/kg) and copper (4.480 mg/kg). The obtained results of moisture content (73.04%), ash (2.53%), crude proteins (1.78%), and total fat content (9.21%), have further confirmed that ajvar is quite nutritious and can fit into various diet plans.
Interest for new strawberry cultivars in the world is increasing due to high demands for nutritionally valuable fruits with good agronomic properties. The aim of this study was to evaluate the fruit quality of three new promising strawberry cultivars - 'Asia', 'Joly', and 'Premy' and to determine their potential for providing high-quality fruits for the market. Among the analyzed parameters physical and biochemical properties of the fruit were measured, followed by a sensory analysis of the fruit attractiveness, taste and aroma. The cultivar 'Joly' had the biggest fruits, with the highest fruit weight, length and diameter. The smallest fruits were present in the cultivar 'Premy'. The highest soluble solids and titratable acidity were present in the cultivar 'Premy', while these parameters were the lowest in the cultivar 'Joly'. The cultivar 'Premy' also had the highest antioxidant capacity, measured by both assays (ABTS and DPPH). The cultivar 'Joly' was superior in comparison to other cultivars regarding the content of phenols and flavonoids, which are important nutritional components of the fruit. Regarding the fruit attractiveness, all the studied cultivars were rated as attractive, but regarding the taste and aroma the cultivar 'Joly' showed the best results and had the highest overall rating. Each of the three analyzed cultivars showed different potential, depending on consumers' preferences towards taste and nutritional value of strawberry fruits.
This study aimed to optimize lavender flower pretreatment, assess the effects of different salt concentrations, and evaluate the use of hydrolat from previous hydro-distillation on essential oil yield and composition. Whole flowers produced as much oil as wet-ground or freshly ground flowers. Contrary to previous studies, NaCl and KCl solutions (3-10%) did not affect maximum oil yield but did alter hydrodistillation kinetics, reducing washing rates and enhancing diffusion by disrupting oil glands and raising the boiling point. Using a mix of recycled hydrolat and fresh water increased oil yield and improved kinetics by enhancing internal oil extraction. The process was successfully modeled using distinct washing and diffusion mechanisms. Both pretreatments of lavender flowers have a significant impact on the essential oil composition. Salt pretreatment enhances the extraction of oxygenated monoterpenes compounds and monoterpenes, while hydrolat addition negatively affects the solubility and volatility of oxygenated monoterpenes. In conclusion, soaking whole lavender flowers in hydrolat-water mixture is an efficient method, reducing both energy and water usage, and lowering operational costs, while simultaneously requiring attention to its impact on the composition.
