Search Results (405)

Self-fluxing Ni-based coatings (NiCrFeBSiC) were deposited through gas-flame spraying and evaluated in three conditions: as-sprayed, flame-remelted, and furnace-heat-treated (1025 °C/5 min). Phase analysis (XRD) revealed FeNi₃ together with strengthening carbides/borides (e.g., Cr₇C₃, Fe₂₃(C,B)₆); post-treatments increased lattice order. Cross-sectional image analysis showed progressive densification (thickness ~805→625→597 µm) and a drop in porosity from 7.866% to 3.024% to 1.767%. Surface roughness decreased from Ra = 31.860 to 14.915 to 13.388 µm. Near-surface microhardness rose from 528.7 ± 2.3 to 771.6 ± 4.6 to 922.4 ± 5.7 HV, while adhesion strength (ASTM C633) improved from 18 to 27 to 34 MPa. Wettability followed the densification trend, with the contact angle increasing from 53.152° to 79.875° to 89.603°. Under dry ball-on-disk sliding against 100Cr6, the friction coefficient decreased and stabilized (0.648 ± 0.070 → 0.173 ± 0.050 → 0.138 ± 0.003), and the counterbody wear-scar area shrank by ~95.6% (0.889 → 0.479 → 0.0395 mm²). Wear-track morphology evolved from abrasive micro-cutting (as-sprayed) to reduced ploughing (flame-remelted) and a polishing-like regime with a thin tribo-film (furnace). Potentiodynamic tests indicated the lowest corrosion rate after furnace treatment (CR ≈ 0.005678 mm·year⁻¹). Overall, furnace heat treatment provided the best structure–property balance (lowest porosity and Ra, highest HV and adhesion, lowest and most stable μ, and superior corrosion resistance) and is recommended to extend the service life of NiCrFeBSiC coatings under dry sliding. Full article

Biofouling on offshore wind farm substructures threatens operational reliability and raises maintenance demands, underscoring the need for effective antifouling strategies. This study presents a 27-month evaluation of fouling development on a conventional non-antifouling coating and self-polishing copolymer (SPC) systems at a South Korean offshore wind farm. Biofouling coverage was assessed through long-term image analysis, and surface energy was characterized via contact angle measurements. Species analyses identified successional communities dominated by barnacles, coralline algae, and bryozoa. The conventional coating showed rapid colonization, exceeding 90% coverage within 10 months, whereas the SPC systems exhibited superior performance by suppressing settlement, though their effectiveness declined over time. Quantitative analysis revealed a clear relationship between higher surface energy and increased fouling rates, highlighting material properties as a key factor in colonization. This study provides one of the first long-term quantitative datasets from South Korean waters, advancing understanding of biofouling dynamics and informing antifouling strategies for offshore wind infrastructure. Full article

Social perception of fishing is dichotomous and is perceived through the prism of stereotypes or intuitive ideas. Popularity of angling and its importance for the environment and the economy force the necessity to examine this issue to improve public acceptance of anglers and optimalisation of sustainable recreational area management. The study is based on a survey of Polish anglers and other people who undertake recreational activities on inland waters. Research aimed to assess the prevalence of stereotypes regarding angling and to verify them based on the preferences and self-reported behaviors indicated by anglers. Most non-anglers (88.6%) do not have a negative opinion of anglers. People with neutral attitudes are more like those with positive opinions. Part of the public (21.7–39.7%), despite associating anglers with negative connotations, does not have a negative opinion of them. Negative opinions are mainly related to concerns about sustainability and other environmental impacts from overharvesting, plus welfare of the captured fish, which was expressed as “torture”. Many of the stereotypes examined were verified as untrue; however, stereotypes concerning the costs and time spent are accurate and show the positive impact of fishing on the economy. Full article

The paper presents a linear optimisation model aimed at improving the design and operational efficiency of home energy systems (HESs). It focuses on integrating photovoltaic (PV) installations, hybrid heating systems, and emerging energy storage systems (ESSs). Driven by the EU climate policy and the evolution of the Polish electricity market, which have caused price volatility, the model examines the economic and technical feasibility of shifting detached and semi-detached houses towards low-emission or zero-emission energy self-sufficiency. The model simultaneously optimises the sizing and hourly operation of electricity and heat storage systems, using real-world data from PV output, electricity and gas consumption, and weather conditions. The key contributions include optimisation based on large data samples, evaluation of the synergy between a hybrid heating system with a gas boiler (GB) and a heat pump (HP), analysis of the impact of demand-side management (DSM), storage capacity decline, and comparison of commercial and emerging storage technologies such as lithium-ion batteries, redox flow batteries, and high-temperature thermal storage (HTS). Analysis of multiple scenarios based on three consecutive heating seasons and projected future conditions demonstrates that integrated PV and storage systems, when properly designed and optimally controlled, significantly lower energy costs for prosumers, enhance energy autonomy, and decrease CO₂ emissions. The results indicate that under current market conditions, Li-ion batteries and HTS provide the most economically viable storage options. Full article

The Polish diaspora’s commitment to maintaining its cultural and linguistic heritage in foreign environments not only enriches their communities but also deepens the understanding of diaspora dynamics in cultural preservation. This article analyzes the narrative development of Polish-speaking children as a means of supporting the maintenance of the Polish heritage language (HL) in Finland. The case study focuses on a family with a visually impaired father and three children. The material was drawn from interviews with the parents, books created by the children on their own initiative, and picture book narratives. Using an ecological approach and narrative analysis, the study explores how children naturally expand their competence in Polish through storytelling. By fostering storytelling skills, children strengthen their linguistic, cultural, and emotional connection to their HL. Narratives enable them to use Polish in meaningful, everyday contexts, creating a natural environment for language practice. Through stories that incorporate elements from Polish, Finnish, and international settings, children develop intercultural awareness, adaptability, and a deeper appreciation for their Polish roots. Storytelling between parents and children in Polish also fosters emotional closeness and reinforces the family’s linguistic bond. It encourages children to communicate with Polish-speaking relatives, such as grandparents, thereby supporting intergenerational language transmission. Full article

The global aviation sector underwent an unprecedented shock due to the COVID-19 pandemic, severely disrupting the passenger flows, flight operations, and revenues of Polish airports. In response, the government launched protective measures under the Anti-Crisis Shield and the COVID-19 Counteraction Fund. This study examines the financial impact of such public support on 12 Polish airports between 2016 and 2022, applying a two-step cointegration ECM framework with Driscoll–Kraay inference. Profitability (ROA, ROE, OM), liquidity, debt, and operational activity indicators were analysed, with particular attention to methodological distortions arising from including subsidies in operating revenues. The results indicate a material decline in profitability from 2020 to 2022, albeit with pronounced heterogeneity across airports. Larger hubs (Warsaw–Chopin, Kraków, Gdansk, Katowice, Poznan, and Wroclaw) demonstrated relative resilience, while many smaller, regionally owned airports (e.g., Bydgoszcz, Lodz, Lublin, Olsztyn-Mazury, Zielona Gora) remained structurally unprofitable despite substantial subsidies. In several cases, profitability, liquidity, and operating activity recovered by 2021–2022, yet the improvement was not uniform: for fiscally dependent airports, transfers merely masked persistent inefficiencies. Passenger volumes, flight operations, and employment emerged as the primary performance drivers, while capital expenditure, turnover of current assets, and liquidity were particularly relevant for ROE. The novelty of this research lies in disentangling the stabilising effect of subsidies from underlying profitability, revealing how non-market revenues distort standard performance metrics and accelerate short-run adjustment dynamics once netted out. The findings demonstrate asymmetric impacts of state aid across ownership structures, i.e., central state control at Warsaw versus regional self-government involvement elsewhere, and highlight structural inefficiencies that weaken systemic resilience. These insights underline the importance of subsidy-adjusted financial indicators, more selective allocation of support, and reporting standards that separate operating from non-market revenues to enhance resilience and ensure sustainable airport operations. Full article

Background: Dietary habits are key determinants of physical and mental health, yet large-scale, contemporary data on these behaviors and their health correlates are crucial for effective public health policy. This study leverages a uniquely large dataset to quantify the eating behaviors of Polish adults and examines how these behaviors relate to socio-demographic characteristics, health status, and subjective well-being. Methods: We analyzed data from 1,196,102 adult respondents who participated in the National Poles’ Health Test, a recurring online survey, between 2019 and 2024. The study used self-reported data on dietary habits, socio-demographic variables, chronic conditions, and self-assessed physical and mental health. Descriptive statistics and comparative analyses, such as the chi-square test, Student’s t-test, or ANOVA, were used. Results: Our findings reveal stark socio-demographic disparities in nutrition. Younger respondents and lower educational attainment were strongly correlated with more frequent consumption of fast food and sugar-sweetened beverages. Crucially, these unhealthy eating patterns were significantly associated with poorer self-rated physical and, notably, mental health (among people who consumed fast food every day, as many as 16.6% rated their mental health as bad, and 6.7% as very bad). In contrast, higher vegetable and fruit consumption correlated with markedly better health outcomes and greater subjective well-being. Conclusions: This large-scale study provides evidence of the profound link between diet and both physical and mental well-being in Poland. The results underscore the urgent need for targeted public health strategies aimed at improving dietary behaviors, particularly among younger and less-educated populations. The strong associations between diet, health status, and well-being highlight the importance of integrating nutritional education into both general healthcare and mental health services. Full article

Background: Adolescence is a particularly vulnerable period for experiencing loneliness. According to the latest statistics, there are worldwide increases in adolescents’ social isolation caused by different psychosocial challenges. A number of different studies have linked a strong belief in being successful at doing something to lower levels of feeling lonely. Objectives: Because we know less about the potential mediators of this relationship, the aim of the current study was to assess: (1) the association between self-efficacy and loneliness; (2) the mediatory role of peer communication. Methods: A total of 191 primary and high school students (M_age = 16.22; SD = 1.44) completed the General Self-Efficacy Scale, the De Jong Gierveld Loneliness Scale, and the Scale of Communication of Adolescents with Peers. Results: The results of the correlation analyses revealed that self-efficacy was negatively associated with loneliness and difficulty in adolescents’ communication with peers. Conversely, self-efficacy was positively associated with openness in adolescents’ communication with peers. Moreover, the outcomes of the PROCESS macro for SPSS (model number 4; Hayes, 2013) showed that openness in adolescents’ communication with peers and difficulty in this communication were mediators in this relationship. Conclusions: Young people who strongly believe in their abilities to achieve success may be more willing to share ideas and personal experiences with others and have less difficulty in communicating with peers, which may lead to a reduced sense of loneliness. Full article

Background/Objectives: Adolescence is a critical period for identity development and self-perception, increasingly shaped by digital media. This study aimed to examine how gender, body mass index (BMI), and Internet use influence body esteem and global self-esteem among adolescents aged 15–18 years old, with particular focus on the psychological impact of digital exposure. Methods: A three-wave online study was conducted using the Computer-Assisted Web Interview (CAWI) technique. The final sample consisted of 500 Polish adolescents (251 girls, 249 boys). Participants completed the Body Esteem Scale (BES) and Rosenberg Self-Esteem Scale (SES) at three time points. The study explored gender differences, the role of BMI, and the impact of time spent online. Results: Girls reported significantly lower BES and SES scores than boys (p < 0.001), despite no significant gender differences in BMI. Time spent online was negatively associated with both body esteem and self-esteem (p < 0.01), with the most pronounced effects among girls using the Internet for more than 4 h daily. Regression analyses identified gender and Internet use as significant predictors of self-perception, while BMI did not. Conclusions: Digital media use, particularly prolonged exposure, appears to be a stronger predictor of adolescent self-perception than objective body measures such as BMI. Girls are especially vulnerable to its adverse effects on both body esteem and global self-esteem. These findings underscore the need for gender-sensitive interventions focused on media literacy, emotional resilience, and healthy digital habits among adolescents. Full article

Background/Objectives: Proper nutrition is crucial for the growth, development, and performance of young football players. Despite higher nutritional needs, physically active adolescents often have a suboptimal diet. This study assessed the diet quality of youth football players aged 11–16 from Poznań, Poland, focusing on the frequency of consuming health-promoting and non-healthy food groups. Methods: Participants were Football Championship School students. A total of 78 boys were analyzed and divided into early (11–13 years) and middle adolescence (14–16 years) groups. Dietary behaviours, nutritional knowledge, physical activity, screen time, and family affluence were assessed using a validated questionnaire (SF-FFQ4PolishChildren). The pro-Healthy Diet Index (pHDI) and non-Healthy Diet Index (nHDI) were calculated based on the frequency of food consumption. Results: The key predictors of the pro-Healthy Diet Index (pHDI) were the Cole index (β = −0.39; p < 0.001), subjective self-assessment of dietary habits (β = 0.23; p = 0.023), and the level of nutritional knowledge (β = 0.22; p = 0.030), explaining 25% of the variance in pHDI. In early adolescence, the Cole index was the main predictor (β = −0.51, p < 0.001, R² = 32%), whereas in middle adolescence, self-assessment of dietary habits (β = 0.49, p = 0.002) and nutritional knowledge (β = 0.34, p = 0.03, R² = 30) were the strongest predictors. Despite high levels of physical activity and positive self-assessment, only 1.28% of participants met all key criteria for a healthy diet. Screen time was negatively correlated with physical activity and positively associated with energy drink consumption. Conclusions: The results highlight a discrepancy between declared knowledge and actual behaviours, emphasizing the need for targeted, multi-level interventions involving families and coaches to improve dietary practices in young athletes. Full article

The aim of this study was to explore the use of neural networks as a decision-support tool for sustainable oilseed processing. The investigation focused on how different production profiles (crude vegetable oil, refined oil, hydrogenated oil and margarine) affect electricity and water use in selected Polish processing plants. The collected data were first grouped with cluster analysis to identify similar operational cases. The clusters were then visualized with a Self-Organizing Map (SOM), producing a two-dimensional topological feature map. This analysis indicated a subset of data for which it was appropriate to build predictive models of electricity and water consumption. Multi-layer perceptron (MLP) neural networks yielded highly accurate predictions of electricity (R² = 0.967 on the test set) and water (R² = 0.967 on the test set) use in oilseed processing. The resulting models can assist in selecting the most energy- and water-efficient processing configuration. Full article

Environmental awareness and sustainability are essential for city development. Therefore, the study examined the attitudes of 1023 Polish Generation Z students from WULS-SGGW in Warsaw, Poland, toward urban trees and willingness to support tree planting. The findings revealed that 75% care about the environment, 93% value nature, and 92% enjoy seeing new trees. Additionally, 74% support funding tree planting, 51% would volunteer, and 39% donate money. However, 54% believe that property owners should be free to cut trees. The Agglomerative Hierarchical Clustering (AHC) method was applied to divide students into clusters. Clusters differed first in students’ attitudes toward trees, from “Tree Lovers” to “Tree Sceptics”, and second in students’ anthropocentric vs. environmental orientation: opposing (“Trees First”) vs. supporting (“People First”) the right to freely cut private trees. An additional questionnaire allowed us to link students’ clusters with importance assigned to positive and adverse tree attributes, like “Attractiveness,” “Usefulness,” and “Danger”. The study results do not provide a clear answer regarding the issue of Polish Generation Z students and the future sustainable development of urban greenery. They want to support trees for practical qualities, beauty, and utility. However, many place an even greater value on their right to self-determination regarding their property, including tree removal. Full article

Anatase is well known for its photocatalytic properties. However, it can be irreversibly transformed into rutile at temperatures above 600–850 °C. This is a major limitation for ceramic tiles with self-cleaning properties, which are usually single-fired at 1100–1250 °C. To avoid this issue, functionalized tiles are often produced by double firing, where the second firing stays below 850 °C. Supporting TiO₂ on kaolinite helps to stabilize the anatase phase even at temperatures above 850 °C. In this study, a photocatalytic coating was specially developed to be suitable for the single-firing ceramic tile process. TiO₂ and TiO₂ with Nb₂O₅ (from 0 to 12 wt.%) were supported on kaolinite. This material was mixed with a glass frit to create a surface texture typical of ceramic tiles. The coated tiles were single-fired at 1185 °C. The self-cleaning performance was evaluated using contact angle (CA) measurements and methylene blue (MB) degradation under UV-A light, on both unpolished and polished surfaces. The polished sample containing 12 wt.% TiO₂ showed the best photocatalytic activity: it degraded 57% of MB and the contact angle decreased from 64° to 30° after UV-A exposure. XPS, FTIR, and FEG-SEM analyses confirmed the effective presence of TiO₂. The results demonstrate that kaolinite-supported TiO₂ is a promising approach for producing self-cleaning ceramic tiles using a single-firing process. Full article

In the past decade, agricultural biogas plants have become one of the key tools driving the energy transition in rural areas. Nevertheless, their development in Poland still lags behind that in Western European countries, suggesting the existence of barriers that go beyond technological or regulatory issues. This study aims to examine how Polish farmers perceive the risks and expected benefits associated with investing in biogas plants and which of these perceptions influence their willingness to invest. The research was conducted in the second quarter of 2025 among farmers planning to build micro biogas plants as well as owners of existing biogas facilities. Geographic Information System (GIS) tools were also used in selecting respondents and identifying potential investment sites, helping to pinpoint areas with favorable spatial and environmental conditions. The findings show that both current and prospective biogas plant operators view complex legal requirements, social risk, and financial uncertainty as the main obstacles. However, both groups are primarily motivated by the desire for on-farm energy self-sufficiency and the environmental benefits of improved agricultural waste management. Owners of operational installations—particularly small and medium-sized ones—tend to rate all categories of risk significantly lower than prospective investors, suggesting that practical experience and knowledge-sharing can effectively alleviate perceived risks related to renewable energy investments. Full article

To address the issue of surface glazing that occurs during prolonged polishing with gel tools, this study employs a triethanolamine (TEA)-based polishing fluid system to enhance the self-sharpening capability of the gel polishing disc. The inhibitory mechanism of TEA concentration on disc glazing is systematically analyzed, along with its impact on the gel disc’s frictional wear behaviour. Furthermore, the synergistic effects of process parameters on both surface quality and material removal rate (MRR) of SiC are examined. The results demonstrate that TEA concentration is a critical factor in regulating polishing performance. At an optimal concentration of 4 wt%, an ideal balance between chemical chelation and mechanical wear is achieved, effectively preventing glazing while avoiding excessive tool wear, thereby ensuring sustained self-sharpening capability and process stability. Through orthogonal experiment optimization, the best parameter combination for SiC polishing is determined: 4 wt% TEA concentration, 98 N polishing pressure, and 90 rpm rotational speed. This configuration delivers both superior surface quality and desirable MRR. Experimental data confirm that TEA significantly enhances the self-sharpening performance of gel discs through its unique complex reaction. During the rough polishing stage, the MRR increases by 34.9% to 0.85 μm/h, while the surface roughness S_a is reduced by 51.3% to 6.29 nm. After subsequent CMP fine polishing, an ultra-smooth surface with a final roughness of 2.33 nm is achieved. Full article