A Two-Stage Method of Localization of Sources of Harmonics in Current in a Power System

The paper deals with localization of sources of harmonics in a power system. At the beginning, the reasons for undertaking investigations are outlined. Then, the theoretical background of the presented method is presented. The method uses examination of the so-called voltage rate to localize the dominant harmonic source. During this examination it is assumed that (i) the voltage and current at the point of common coupling are measured, (ii) at the first stage internal impedances of equivalent sources representing the customer and utility sides are known, (iii) at the second stage only approximate knowledge of the mentioned impedances is possessed. After the principle of the method is described, features of the method are analyzed. At the end, the attention is paid to the main advantages of the method

Moral Disengagement and Risk Prototypes in the Context of Adolescent Cyberbullying: Findings From Two Countries

Cyberbullying is associated with a wide range of mental health difficulties and behavioral problems in adolescents and research is needed to better understand psychological correlates of this behavior. The present study used a novel model that incorporated Social Cognitive Theory and the prototype/willingness model to identify the correlates of behavioral willingness to engage in cyberbullying in two countries. Adolescent students were randomly selected from secondary schools in Italy (n = 1710) and Greece (n = 355), and completed anonymous measures of moral disengagement, descriptive norms, risk prototype evaluations and behavioral willingness to engage in cyberbullying. Hierarchical linear regression analyses showed that willingness to engage in cyberbullying was associated with moral disengagement, prototype evaluations and descriptive social norms in Italy, and with gender, moral disengagement and descriptive social norms in Greece. Regression-based multiple mediation modeling further showed that the association between moral disengagement and cyberbullying willingness was mediated by prototype evaluations in Italy and by descriptive norms in Greece. The implications of our findings are discussed in the context of self-regulating cyberbullying perpetration in adolescents and informing school-based policies and interventions to prevent cyberbullying behavior

Adolescents' involvement in cyber bullying and perceptions of school: the importance of perceived peer acceptance for female adolescents

Young people are spending increasing amounts of time using digital technology and, as such, are at great risk of being involved in cyber bullying as a victim, bully, or bully/victim. Despite cyber bullying typically occurring outside the school environment, the impact of being involved in cyber bullying is likely to spill over to school. Fully 285 11- to 15-year-olds (125 male and 160 female, M age = 12.19 years, SD = 1.03) completed measures of cyber bullying involvement, self-esteem, trust, perceived peer acceptance, and perceptions of the value of learning and the importance of school. For young women, involvement in cyber bullying as a victim, bully, or bully/victim negatively predicted perceptions of learning and school, and perceived peer acceptance mediated this relationship. The results indicated that involvement in cyber bullying negatively predicted perceived peer acceptance which, in turn, positively predicted perceptions of learning and school. For young men, fulfilling the bully/victim role negatively predicted perceptions of learning and school. Consequently, for young women in particular, involvement in cyber bullying spills over to impact perceptions of learning. The findings of the current study highlight how stressors external to the school environment can adversely impact young women's perceptions of school and also have implications for the development of interventions designed to ameliorate the effects of cyber bullying

youth Digital Skills Indicator:Polish questionnaire

The youth Digital Skills Indicator was developed as part of the ‘Youth Skills (ySKILLS)’ project and added to the ‘From Digital Skills to Tangible Outcomes’ digital skills measurement toolkit.Please read the accompanying document on the underlying rationale for these scales and on how to create and use composite scales in the following document: Helsper, E.J., Schneider, L., van Deursen, A.J.A.M., van Laar, E. (2021). The youth Digital Skills Indicator: Report on the conceptualisation and development of the ySKILLS digital skills measure. KU Leuven, Leuven: ySKILLS. Available at: https://yskills.eu

Utilizing Fuel and Energy SectorWaste as Thermal Insulation Materials for Technical Buildings

О. Antoniuk: ORCID 0000-0001-6497-3061ENG: The growing demand for sustainable construction materials has prompted intensive research into the potential reuse of waste from the fuel and energy sector as effective thermal insulation materials. This study examines the feasibility of utilizing ash–slag mixtures, fly ash, and aluminosilicates as insulation materials for technical buildings. These materials were selected due to their availability and potential to improve energy efficiency in construction. Practical tests were carried out to determine the thermal conductivity coefficients of various samples, which were produced using different cement mixtures as binders to ensure adequate structural strength. The results demonstrated that the use of industrial waste-derived materials not only provides satisfactory thermal insulation properties but also contributes to environmental sustainability by reducing the challenges associated with the disposal of industrial by-products. The study highlights the crucial role of cement as a binder, enhancing the mechanical strength and durability of the insulation samples. The integration of ash–slag mixtures, fly ash, and aluminosilicates into the construction sector may foster the adoption of more environmentally friendly building practices, thereby supporting a circular economy and mitigating the environmental impact of construction activities. The study showed that the lowest thermal conductivity coefficient (0.24 W/m·K) was achieved for mixtures containing fly ash and cement, while the highest value (0.30 W/m·K) was recorded in samples incorporating aluminosilicates. The obtained results confirm the effectiveness of fly ash as a cost-efficient additive that improves the thermal insulation properties of the material.Dnipro University of Technology, Dnipro, Ukraine; AGH University of Krakow, Kraków, Polan

Adolescent well-being and learning in times of COVID-19-A multi-country study of basic psychological need satisfaction, learning behavior, and the mediating roles of positive emotion and intrinsic motivation

The sudden switch to distance education to contain the outbreak of the COVID-19 pandemic has fundamentally altered adolescents' lives around the globe. The present research aims to identify psychological characteristics that relate to adolescents' well-being in terms of positive emotion and intrinsic learning motivation, and key characteristics of their learning behavior in a situation of unplanned, involuntary distance education. Following Self-Determination Theory, experienced competence, autonomy, and relatedness were assumed to relate to active learning behavior (i.e., engagement and persistence), and negatively relate to passive learning behavior (i.e., procrastination), mediated via positive emotion and intrinsic learning motivation. Data were collected via online questionnaires in altogether eight countries from Europe, Asia, and North America (N = 25,305) and comparable results across countries were expected. Experienced competence was consistently found to relate to positive emotion and intrinsic learning motivation, and, in turn, active learning behavior in terms of engagement and persistence. The study results further highlight the role of perceived relatedness for positive emotion. The high proportions of explained variance speak in favor of taking these central results into account when designing distance education in times of COVID-19.Peer reviewe

The Effect of Biological Corrosion on the Hydration Processes of Synthetic Tricalcium Aluminate (C3A)

This paper presents a study related to the biological degradation of a tricalcium aluminate (C3A) phase treated with reactive media from the agricultural industry. During one month of setting and hardening, synthetic C3A was subjected to corrosion in corn silage, pig slurry and chicken manure. The hardening process of the C3A phase in water was used as a reference sample. The phase composition and microstructure of the hydrating tricalcium aluminate slurries were characterised by X-ray diffraction (XRD), thermal analysis (DTA/TG/DTG/EGA), scanning microscopy (SEM, EDS) and infrared spectroscopy (FT-IR). In the samples studied, it was observed that the qualitative and quantitative phase composition of the synthetic tricalcium aluminate preparations changed depending on the corrosion exposure conditions. The main crystalline phases formed by the hydration of the examined samples in water as well as in corrosive media were the catoite (Ca3Al2(OH)12) and hydrocalumite (Ca2Al(OH)7·3H2O) phases. Detailed analysis showed the occurrence of secondary crystallisation in hydrating samples and the phases were mainly calcium carbonates (CaCO3) with different crystallite sizes. In the phase composition of the C3A pastes, varying amounts of aluminium hydroxides (Al(OH)3) were also present. The crystalline phases formed as a result of secondary crystallisation represented biological corrosion products, probably resulting from the reaction of hydrates with secondary products resulting from the metabolic processes of anaerobic bacterial respiration (from living matter) associated with the presence of bacteria in the reaction medium. The results obtained contribute towards the development of fast-acting and bio-corrosion-resistant special cements for use in bioenergetics

Electronic Aggression among Adolescents

The chapter is focused on the problem of electronic aggression (conducted via the Internet or mobile phones) in the context of young people as potential victims and perpetrators of such aggression. The text addresses two main issues: the potential novelty of electronic aggression and its potential distinctive features and the diversity of electronic aggression acts (with a proposal of typology). The first aspect is analyzed through the new model – ABACUS that could be used to compare electronic and traditional aggression. The chapter presents also a typology of electronic aggression based on the victim’s identity and his/her relationship with a young person who is a perpetrator. The presented theories and discussions are illustrated with new data from two Polish projects on students and teachers experiences with electronic aggression.</jats:p

A Two-Stage Method of Localization of Sources of Harmonics in Current in a Power System

The paper deals with localization of sources of harmonics in a power system. At the beginning, the reasons for undertaking investigations are outlined. Then, the theoretical background of the presented method is presented. The method uses examination of the so-called voltage rate to localize the dominant harmonic source. During this examination it is assumed that (i) the voltage and current at the point of common coupling are measured, (ii) at the first stage internal impedances of equivalent sources representing the customer and utility sides are known, (iii) at the second stage only approximate knowledge of the mentioned impedances is possessed. After the principle of the method is described, features of the method are analyzed. At the end, the attention is paid to the main advantages of the method