Search Results (49)

The rapid growth of electromobility and the increasing deployment of EV chargers emphasize the importance of pulse rectifiers with built-in power factor correction (PFC) filters. The new switching power devices offer higher converter switching frequencies, which enable a decrease in nominal values of passive components, such as inductors and capacitors, and their physical dimensions. Devices like CoolMOS and GaN enable operation with low switching power, but are usually constructed for lower drain-source voltage. From this point of view, the Vienna Rectifier is a prospective type of pulse rectifier with built-in PFC because of its reduced blocking-voltage requirements for the power transistors. Nevertheless, faster switching semiconductor devices with lower switching gate charge require more precise driving circuit tuning and setup. There are many scientific papers focused on the driving setup and techniques of the power transistors applied in H-bridge topologies. The purpose of this paper is to investigate the commutation loop and the related switching phenomena of the Vienna Rectifier topology. This paper evaluates the driver setup for a CoolMOS-based Vienna Rectifier with anti-serial connection of transistors forming a bidirectional switch. The switching transients are analyzed and simulated. Subsequently, the real driver settings are evaluated on the real prototype. Full article

In a short 11 nt dye-labelled oligonucleotide hybrid, we investigated the oxidation of a single guanine, G, to 8-oxo-7,8-dihydroguanosine, 8oG, a reaction proceeding via two reaction pathways. In single-molecule fluorescence traces, we were able to detect the conversion of G to 8oG and assign different reaction pathways. Reactions are initiated by a photoinduced electron transfer to the dye, creating a G radical cation, G^•+, which is in equilibrium with the neutral G radical, G(−H)^•. Results demonstrate that 8oG formation via water addition to G^•+ proceeds within less than the time resolution of 150 ms. The reaction of G(−H)^• with superoxide is more than 1000 times slower due to the formation of an intermediate with a lifetime of minutes. The overall yield of 8oG formation is low but increases considerably upon addition of dithiothreitol, thus preferring water addition over reactions depending on the presence of oxygen. Our results highlight the advantages of single-molecule real-time technology for the investigation of chemical reactions and reaction pathways. The method enables the direct observation of product formation comparable to fast kinetic methods, including flash photolysis and laser spectroscopy, but on much longer timescales. Time-resolved measurements over minutes to hours not only allow monitoring of reaction sequences that show the formation and decay of products and intermediates, but also the order of their appearance, information that is lost in classical analysis. Product yields can be obtained by counting events, in contrast to ensemble measurements that require considerable manipulation, during which intermediates may get lost. Full article

The objective of this paper is to demonstrate the morphometric diversity of 172 Polish Koniks from the largest Polish breeding centers and to assess their genetic diversity by estimating the effective population size (N_e) and heritabilities (h²) of the studied traits. The animals were bred under a stable housing system. Horses of both sexes aged 3 to 24 years were analyzed. Each horse was characterized with 40 metric traits. Multifactorial analyses (PCA, DA) and the REML method were applied to reveal the exterior differentiation and the development of distinct morphometric types. The findings established that the metric traits with high discriminant power include sections constituting segments of limbs. The elongation of segments, especially the pelvic limb—which serves a driving function—may be associated with deliberate breeding efforts aimed at improving the motor abilities of these horses. Estimates of heritability were high for eight traits, including sternal height (h² = 0.81) and withers height (h² = 0.75), while the effective population size was N_e = 651. Although estimated with large standard errors due to the limited number of individuals studied, these results indicate the possibility of effectively conducting the genetic part of the conservation program for this breed. Koniks are a conservative breed, which creates an obligation for a comprehensive assessment of their current suitability for various forms of saddle and light draft use. Research using the methodology presented in this paper is worth repeating regularly to provide particularly valuable insights from a long-term perspective. Full article

The growing volume of fiber-reinforced polymer composite waste creates an urgent need for efficient recycling technologies. While solvolysis effectively breaks down thermoset matrices for fiber reinforcement recovery, the process generates hydrocarbon-rich liquid by-products that require further management. This study validates the use of these liquid recycling streams—derived from the solvolysis of unsaturated polyester and epoxy resins—as sustainable carbon precursors for the growth of carbon nanomaterials. Synthesis was performed via catalytic chemical vapor deposition (CVD) at 850 °C using iron nanoparticles impregnated on a zeolite substrate. Morphological analysis confirmed the production of one-dimensional nanostructures (carbon nanotubes/nanofibers), with average diameters below 100 nm. Raman spectroscopy revealed a high degree of graphitization, with I_D/I_G ratios ranging from 0.25 to 0.58, which is comparable to structures synthesized from conventional precursors. Thermogravimetric analysis (TGA) demonstrated high thermal stability and carbon purity reaching up to 90.3%. These findings demonstrate a viable upcycling pathway that enhances the economic attractiveness of composite recycling by transforming waste into advanced nanomaterials. Full article

Background/Objectives: Sensory properties of food, such as taste and smell, are the main factors influencing the preference or rejection of a given food product, especially among children. The aim of this study was to compare the food preferences of teenagers with diabetes to those of a group of healthy children. Additionally, we assessed the influence of children’s taste perception on food preferences. Methods: The study involved 102 adolescents with type 1 diabetes aged 11–15, including 55 girls and 47 boys. We used a questionnaire that consisted of 63 photos of various food products, dishes, and drinks. For the taste evaluation, we used paper strips impregnated with four basic tastes (sweet, sour, bitter, and salty). Results: Healthy teenagers were more likely to self-report preferences for sweet foods. The overall preference score for sweet products included in the study was higher in the control group. The median score for this group was 4.21 (3.92–4.42), and for the diabetes group, the median score was 4.03 (3.68–4.26) (p = 0.0008). Preferences for bitter-tasting vegetables and fruits were clearly higher in teenagers with type 1 diabetes. The overall preference score for bitter taste products included in the study was higher in the diabetes group. The median score for this group was 3.71 (3.00–4.14), and for the control group, the median score was 2.86 (2.14–3.50) (p < 0.0001). Conclusions: Adolescents with diabetes showed greater acceptance of certain bitter-tasting foods compared to their healthy peers. Lower preferences for sweet and higher preferences for bitter foods can be taken into account in establishing nutritional plans for adolescents with type 1 diabetes. Full article

Despite widespread implementation, current waste management practices—such as landfilling and incineration—are associated with significant environmental drawbacks, including greenhouse gas emissions and resource loss. Consequently, the search for more sustainable and environmentally friendly waste valorization methods has highlighted oxidative liquefaction as a promising pathway. This study focused on two critical waste streams: personal protective equipment (PPE) and municipal solid waste (MSW). These categories were selected due to the significant increase in PPE waste generated during the recent pandemic, as well as the need to develop effective strategies to address potential future surges in such waste streams. Experiments were carried out at 200–300 °C, with waste-to-liquid ratios of 3–7% and oxidant concentrations of 30–60 wt.%. The aim was to demonstrate the potential of oxidative liquefaction as a thermochemical conversion route for resource recovery, enabling the breakdown of the organic matrix of PPE and MSW into valuable liquid products such as fine chemicals or a source of carbon in biotechnological processes. Chromatographic analyses, combined with chemometric methods, revealed how temperature, waste-to-liquid ratio, and oxidant concentration affected the yield and composition of oxygenated chemical compounds (OCCs). Using raw chromatographic data directly in optimization eliminated the need for manual gas chromatography (GC) signal processing and provided a faster approach to process evaluation. The results confirmed distinct differences in degradation behavior and OCC formation between PPE and MSW, with maximum yields of 183–212 gOCC/kg for PPE and 51–69 gOCC/kg for MSW. These findings highlight the strong influence of physicochemical waste properties on degradation and product composition. Overall, oxidative liquefaction shows significant potential as a waste-to-value strategy, supporting renewable fuels, chemical precursors, and circular economy development within the framework of biomass, biofuels, and waste valorization. Full article

Carbon fiber is essential in many industries. Since primary production is highly energy-intensive, recycling technologies are being sought. A goal of the research was to develop at a laboratory scale a chemical recycling method aimed at recovering carbon fiber. Two variants of the method have been established and environmentally compared with a primary production version. Methods: The life cycle assessment methodology has been used to assess and quantify the environmental impacts. The cradle to gate analysis was performed with the functional unit defined as a production of 1 kg of carbon fiber. Results: The best environmental option turned out to be a developed chemical recycling technology named Scenario 1. It is a solvolysis performed using an ambient-pressure-operated batch reactor connected to a reflux condenser and an inert gas supply tank, using an ethylene glycol and potassium hydroxide solution. The worst case appeared to be the second variant of the chemical recycling, named Scenario 2 (plasma-enhanced nitric acid solvolysis). Conclusions: In Scenario 1, a production of the ethylene glycol was recognized as a key environmental driver, while in Scenarios 2 and 3 the energy-related impact was the most influential. Full article

The recycling of Carbon Fibre-Reinforced Polymers (CFRPs) is becoming increasingly crucial due to the growing demand for sustainability in high-performance industries such as automotive and aerospace. This study investigates the impact of two chemical recycling techniques, chemically assisted solvolysis and plasma-enhanced solvolysis, on the morphology and properties of carbon fibres (CFs) recovered from end-of-life automotive parts. In addition, the effects of fibre sizing are explored to enhance the performance of the recycled carbon fibres (rCFs). The surface morphology of the fibres was characterised using Scanning Electron Microscopy (SEM), and their structural integrity was assessed through Thermogravimetric Analysis (TGA) and Raman spectroscopy. An automatic analysis method based on optical microscopy images was also developed to quantify filament loss during the recycling process. Mechanical testing of single fibres and yarns showed that although rCFs from both recycling methods exhibited a ~20% reduction in tensile strength compared to reference fibres, the application of sizing significantly mitigated these effects (~10% reduction). X-ray Photoelectron Spectroscopy (XPS) further confirmed the introduction of functional oxygen-containing groups on the fibre surface, which improved fibre-matrix adhesion. Overall, the results demonstrate that plasma-enhanced solvolysis was more effective at fully decomposing the resin, while the subsequent application of sizing enhanced the mechanical performance of rCFs, restoring their properties closer to those of virgin fibres. Full article

This paper investigates the impact of product-related experience on consumers’ perception of their knowledge about extended warranties for automobiles in Germany and its implications for sustainability. Utilizing a structural equation model and analyzing data from 467 participants, the study explores the influence of general self-confidence and product-related experience on both subjective and objective knowledge. The empirical findings highlight that while high general self-confidence and product-related experience significantly shape participants’ subjective knowledge, they do not have a similar impact on objective knowledge. Notably, previous possession, representing the highest level of product-related experience, emerges as the primary influencing factor on participants’ subjective knowledge. Surprisingly, subjective and objective knowledge does not significantly influence participants’ willingness to pay. The analysis presented in this paper underscores the importance of understanding the distinction between self-perceived knowledge and objective knowledge, particularly concerning extended warranties for automobiles and the need for accurate knowledge dissemination to inform sustainable consumer choices. Full article

Various waste streams including municipal solid waste (MSW), polymer waste from personal protective equipment (PPE) used in medical fields, and composite waste from wind turbine blades (WTBs) demand modern waste management and recycling approaches. Ultimate and proximate analysis of mentioned samples revealed a higher content of carbon—28.2 ± 8.0, 80.1 ± 2.3, and 50.3 ± 2.3, respectively—exhibiting sufficient potential to be converted into secondary carbon-based compounds. For this purpose, oxidative liquefaction of selected waste materials was carried out following a detailed experimental plan, a centred composite design for WTBs, and a central composite face-centred plan for MSW and PPEs. Temperature, pressure, oxidant concentration, reaction time, and waste-to-liquid ratio were the parameters of key interest, and their values were tested at a range of 200–350 °C, 20–40 bar, 15–60%, 30–90 min, and 3–25%, respectively, depending upon the type of waste. As a result, total polymer degradation (TPD) was recorded for three types of waste and the results were satisfactory, encouraging the decomposition of primary waste in liquid oxygenated chemical compounds (OCCs). Gas Chromatography with Flame Ionisation Detection (GC-FID) helped us quantify the number of OCCs for each waste sample. Energy consumption during the process was also recorded and optimisation of the experimental plan based on maximum TPD and OCCs yields against the minimum energy consumption was performed to make the process tech-economic. Full article

This work aims to assess the effect of the operating parameters of the gasifying agent preheating temperature and equivalence ratio (ER) on the conversion of sewage sludge (SS) to syngas through gasification and combined heat and power (CHP) generation. A novel gasification model was simulated in Aspen Plus to represent a fixed-bed updraft gasifier to generate syngas from SS through an equilibrium approach restricted by temperature. The novelty of this work is that the model was developed by applying the gasifying agent preheating temperature as an operating variable instead of the gasification temperature. It was calibrated by using a set of experimental values and then validated by comparing the numerical results with the experimental outcomes related to nine different operating conditions of air preheating temperatures and ER. A good agreement between the simulation and experimental results was observed. The optimum gasification process parameters of the air preheating temperature and ER were predicted to be 150 °C and 0.2, respectively. The CHP generation potentiality of SS was assessed to be 2.54 kW/kg SS as dry solids (DS), of which 0.81 kW was electrical and the remainder was thermal power. The conversion of SS to CHP through the proposed treatment can reduce 0.59 kg CO₂/kg SS as DS emissions compared with that of natural gas combustion to generate a similar quantity of energy. Full article

Pyrolysis is one of the most popular methods for the thermal conversion of biomass-derived materials, which can be applied to produce valuable products such as biochar, bio-oil, and pyrolysis gas. However, this does not change the need for more precise data on the products obtained from such processes under different conditions, using different types of reactors or types of biomass material. Pyrolysis products can have a high energy value and have been extensively studied. In the presented research, three potential energy feedstocks from waste biomass, wheat cereal straw (CS), tobacco waste (TW), and furniture waste (FW) were comprehensively evaluated in terms of product yields, as well as the chemical composition of the volatile products of the pyrolysis process using the pyrolysis–gas chromatography–mass spectrometry technique and the chemical distribution of the products obtained under fixed-bed pyrolysis conditions. The obtained results were compared to data from the literature, which provided thorough information on the pyrolysis of biomass materials in diverse systems. The research identified the primary elements of the liquid fraction, such as N-compounds, furans, phenols, benzene, PAHs, aldehyde-ketone-alcohol, and organic acids, which were the main constituents of the liquid fraction, and the concentration of non-condensable components of gaseous products. The research discussed in this article provides a comprehensive approach to the thermal conversion of biomass materials, which, depending on their origin, processing conditions, and methodologies, can be utilised for more than only energy production. Full article

Hypertension and dyslipidemia are major risk factors for cardiovascular disease. Studies on the association between abnormal levels of lipids and hypertension have yielded inconsistent results. The aim of this study was to examine the prevalence of hypertension and dyslipidemia and its risk factors in young Polish adults. Furthermore, the association between plasma lipid levels and the risk of hypertension was determined. A cross-sectional study was conducted among 115 volunteer participants. Blood pressure was measured using an automated oscillometric sphygmomanometer. Blood lipids were analyzed from a fasting blood sample received by finger prick. Body fat percentage was assessed using a bioelectrical impedance analysis device. Socioeconomic and lifestyle factors (age, date of birth, place of residence, screen time, and tobacco use) were self-reported by the participant. The prevalence of hypertension was higher in men than in women (61.5 vs. 21.3%). The prevalence of elevated TC, TG, high LDL, and low HDL was 22.6%, 7.8%, 38.3%, and 13.9%, respectively. Spending more than 2 h daily in front of a computer was identified as a significant predictor of hypertension and elevated TG levels (p < 0.05). A high number of cigarettes smoked daily was a significant risk factor for hypertension (p = 0.047). Hypertension contributed to a higher risk of abnormal values of TC (OR = 5.89), LDL (OR = 5.38), and TG (OR = 9.75). Participants with hypertension were more likely than normotensive subjects to have elevated levels of TC, LDL, and TG. The prevalence of hypertension was significantly higher in young men than in women. BMI was associated with the prevalence of hypertension and elevated TC levels. Spending more than 2 h per day in front of a computer contributed to the prevalence of hypertension and elevated TG levels. Participants with hypertension smoked a higher number of cigarettes daily compared to those with normotension. Full article

This review comprehensively examines biochar, an essential material in an era of climate change for reducing carbon dioxide (CO₂) emissions into the atmosphere. It is inconspicuous, black, lightweight, and very porous, and is produced through the thermal conversion of biomass. Our literature review highlights biochar’s expansive application possibilities. Firstly, its potential to improve soil quality and sequester CO₂ has been examined, as well as its utilization in iron and steel manufacturing to minimize the quantity of coke and ultimately reduce CO₂ emissions. In industrial manufacturing, the complete elimination of coke can promote environmental neutrality, which is achieved using biochar from biomass for its extrusion. Furthermore, biochar is becoming increasingly significant in modern energy storage technologies and as an important additive in Pickering emulsions, which are also employed in energy storage systems. Additionally, the use of carbon black is a broad topic, and this review illustrates where it can be successfully utilized, especially in environmentally sensitive areas. Full article

A novel diagnosis method based on the rotor slip is proposed in the paper to correctly detect current and speed sensor failures during the induction motor drive (IMD) operation. In order to enhance reliability and avoid confusion in the diagnosis algorithm due to the influence of measured signal quality, each fault type is determined in a priority order defined by the diagnosis method. Based on the features of the IMD applying the field-oriented control (FOC) technique, an innovative model uses the measured currents and reference speed as the input signals to estimate the rotor slip for the current sensor fault detection. After verifying the quality of the feedback of the current signals, a speed sensor fault function is continued, and performs according to relations among the reference speed, estimated speed based on the sliding mode method, and measured rotor speeds. Finally, the estimated quantities are selected to replace the wrong measured current or speed signals. The feasibility of the proposed approach is verified by simulations using Matlab-Simulink software as well as by practical experiments using an IMD prototype with a rated power of 2.2 kW and a DSC-TMS320F28335-based control system. The obtained simulation and experimental results demonstrated the feasibility, effectiveness, and reliability of the proposed diagnosis technique in detecting sensor failures and maintaining the stable operation of the IMD. Full article