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School Connectedness Impact on Adolescent Weekly Depression and Anxiety: Based on the Self-Acceptance
No full textAdolescent mental health has become a growing public health concern, with depression and anxiety emerging at increasingly younger ages. This study investigates the protective role of school connectedness in alleviating adolescent psychological distress and explores the mediating mechanism of self-acceptance. A weekly diary method was employed over seven weeks with 463 middle school students in China. Using multilevel mediation analysis, results indicated that higher levels of school connectedness significantly predicted lower levels of both depression and anxiety. Moreover, self-acceptance partially mediated these associations, suggesting that the psychological benefits of a supportive school environment operate through improved self-concept. The study’s 2-2-1 multilevel model demonstrated good model fit and robust indirect effects. These findings highlight the importance of fostering a sense of belonging and self-worth within school contexts to promote adolescent mental well-being. The use of ecological, time-sensitive methods also underscores the need for dynamic approaches in developmental mental health research. Implications for school-based interventions are discussed
The Rhetoric of “Catiline” in Cicero and Sallust: Plural Authenticities in Roman Crisis
No full textCatiline became a portable paradigm for Roman arguments about law, virtue, and emergency power. This essay reads Cicero’s in Catilinam I alongside Sallust’s Bellum Catilinae to show how genre - live oratory versus retrospective historiography - governs what can be seen, said, and silenced. In Cicero, a politics of vision structures authority: the consul claims to “see” the conspiracy and performs guardianship in the moment of crisis. In Sallust, two internal threads organize the history: the narrator’s moral frame, which situates the revolt within a longer arc of Republican decay; and the staged debate in the Senate, where “Caesar” and “Cato” appear as Sallust’s constructed exempla - lenity and legality versus austere virtue. Read together, these texts yield not one Catiline, but plural authenticities performed under pressure: Cicero enacts custodial vigilance; Sallust’s narrator models moral historiography; his Caesar rehearses clementia as precedent; his Cato insists on severitas. Across both, three recurring features structure crisis-talk: bad precedents, manufactured emergencies, and exemplary violence
Research on gear fault diagnosis for nuclear power circulating water pump based on deep neural network
No full textIn nuclear power circulating water pump systems, gears, as critical transmission components, operate in low-speed, heavy-load environments and are crucial for maintaining the stable operation of the pump. To significantly enhance the efficiency and accuracy of fault diagnosis, this paper proposes a gear fault diagnosis technology based on deep neural networks. Efficient Fast Fourier Transform (FFT) techniques are employed to extract frequency domain samples containing rich fault information. Subsequently, a deep neural network model is designed and trained to automatically extract deep features from the frequency domain signals and accurately identify different fault types. By comparing the performance of various deep neural network models, precise diagnosis of gear faults in nuclear power circulating water pumps is achieved. This method is of significant importance for improving nuclear power safety, optimizing plant operational efficiency, and enhancing economic benefits
Regulating the electronic structure of two-dimensional boron arsenide via deep elastic strain: A first-principles study
No full textTwo-dimensional boron arsenide (2D-BAs) represents an emerging III–V semiconductor with substantial potential for high-frequency electronic and optoelectronic applications. However, its physical properties under applied strains remain largely unexplored. Employing first-principles calculations, we systematically investigate the mechanical strength of 2D-BAs and the influence of uniaxial tensile strain on its electronic band structure. Our findings reveal significant anisotropy in the band gap response: it decreases monotonically along the zigzag direction, while along the armchair direction, it first increases to a maximum of 1.46 eV at 7% strain before declining. Furthermore, a direct-to-indirect band-gap transition occurs at critical strains of 9% (zigzag) and 14% (armchair). This work demonstrates that strain engineering serves as an effective strategy for tuning the electronic properties of 2D-BAs
EPL 40th anniversary highlight: Dynamics of Dzyaloshinskii domain walls in ultrathin magnetic films by André Thiaville et al.
No full textMechanical Performance of Palm Shell Ash-Based Geopolymer Mortar with Silica Fume as Cement Substitute
No full textThe increasing demand for cement in the construction industry has contributed significantly to environmental degradation and global carbon emissions due to the energy-intensive clinker production process. In response, this study investigates a sustainable alternative in the form of geopolymer mortar synthesized from palm shell ash (PSA) a waste material from the palm oil industry that is rich in silica and alumina as a partial or full replacement for Portland cement. The research aims to evaluate the influence of silica fume additions (0%, 5%, 10%, 15%, and 20%) on the mechanical properties of geopolymer mortar, particularly flexural strength and compressive strength. The geopolymer paste was activated using a combination of 10 M sodium hydroxide (NaOH) and sodium silicate (Na2SiO3), with the addition of 1% superplasticizer to enhance workability. A total of 45 prism-shaped specimens (4×4×16 cm) were cast and tested at three curing ages: 3, 7, and 28 days, under standard laboratory conditions. The results demonstrate a clear positive correlation between the increase in silica fume content and the development of mechanical strength over time. At 28 days, the flexural strength reached a maximum of 10.69 MPa, while the compressive strength peaked at 52.87 MPa with 20% silica fume. This improvement is attributed to the enhanced polymerization reaction and the pozzolanic contribution of silica fume, which refines the pore structure and increases matrix density. The study concludes that palm shell ash, when combined with silica fume and alkaline activation, shows significant potential as an eco-friendly binder for use in geopolymer mortars. These findings support the material's viability as a sustainable cement substitute, offering both environmental benefits and satisfactory mechanical performance for use in green construction applications
Blockchain and Digital Platforms for Transparency and Visitor Management in Sustainable Eco-Tourism
No full textBlockchain and digital platforms are increasingly recognized as having the potential to increase transparency, accountability and trust in visitor management, and to shift from the traditional assumption that "digitalization" will become transformative rather than merely supportive. Applications of digital platforms are becoming more visible in the tourism sector globally, but limited evidence is known about the dynamic interaction between transparency mechanisms in blockchain-enabled systems. In this study, we examine how blockchain integration within digital visitor management platforms can help to understand transparency dynamics, along with the governance, trust and engagement dimensions of this digital transition. The interaction of governance variables through longitudinal platform and visitor data is also examined, and feedback effects help to improve the understanding of sustainable accountability mechanisms. We combine a quantitative time-series analysis of the current digital governance framework around eco-tourism platforms, in Uzbekistan. We support our analysis of major governance variables in transparency and visitor engagement with econometric modeling using Vector Auto Regression. The findings in the empirical analysis explain why transparency mechanisms in blockchain-enabled platforms moved beyond the linear adoption logic but also affected differently those stakeholder groups. Our results show that blockchain does not only give greater visibility to governance processes that are institutionally embedded and what can be done to stabilize this transition. We believe these findings have important implications in the governance of eco-tourism platforms, and the policy debate on transparency, trust, and sustainable visitor management
Analyzing solar panel power based on light intensity at different wavelengths
No full textThe performance parameters of a photovoltaic (PV) solar system are investigated in this study at different light wavelength, irradiance levels and temperature conditions. The electrical performance of a monocrystalline silicon solar panel, employed as the main energy conversion element, was investigated under laboratory controlled light. The characteristics are open circuit voltage (Voc), short circuit current (Isc), maximum power output, and efficiency. Spectrum fluctuations were simulated using red, blue and yellow high brightness LEDs. The irradiance was measured with a calibrated solar power meter and it was set by neutral density filters. By observing the panel surface using a thermocouple sensor and changing surrounding conditions, temperature effects were examined. Experimental results show that the PV output was strongly depending on both irradiance and spectral wavelength, shorter wavelength (blue light) contributed a higher voltage but longer wavelength (red light) generated a higer current but worse efficiency. Furthermore, the negative temperature coefficient of silicon cells meant that when the panel was heated, a significant decrease in voltage and overall performance occurred. The investigations provide valuable information in designing solar energy systems over different climatic conditions and demonstrates the influence of spectral- as well as temperature-induced effects relevant to the performance of PV
Removal of micropollutant from Samaraa drinking water using granular activated carbon: Review
No full textIn Samaraa, Iraq, the quality of drinking water is still getting worse because of micropollutants from drugs like carbamazepine and pesticides like atrazine, as well as PFAS that don't dissolve. This destruction affects the Samaraa dam, which is an important reservoir for the Tigris River and puts millions of lives at risk. Conventional treatments like coagulation, filtration, and chlorination are not very effective since they destroy health-threatening residues and harm the riverine ecology. These treatments only get rid of fewer than 30% of these trace level pollutants (from ng/L to μg/L). With a surface area of more than 1000 m2/g and the ability of granular activated carbon (GAC) to adsorb better, it is a good treatment option. This study consolidates global research initiatives to evaluate the efficacy of the GOU-based GAC technique in addressing Samara's complex high natural organic matter (NOM) and pollution matrix. This work endeavors to address the notable deficiency of customized GAC model research concentrated on this region. The results show that GAC can use Van der Waals forces and adjustable pores to catch both polar and nonpolar PFAS and pharmaceutical medicines. Sadly, the rivalry from DOC and regeneration makes it too expensive for Iraq to use these systems because the country's infrastructure isn't ready for them. Operational optimization, like increasing the empty bed contact time (EBCT), gives more time for removal, but prices and local capacity are still problems. Samara and the surrounding area will be safer for people's health and the environment. Some people even think that GAC could update Samara's facilities, but that's not possible. Sadly, the limits make it clear that we need solutions that are based in the area. Strategic pilot programs combined with prolonged monitoring are set to address deficiencies in data and knowledge. This review not only talks about how GAC can help Samaraa, but it also helps the discourse of using advanced medicines in developing areas that really need clean water and good ways to clean up pollution. This review looks at how granular activated carbon (GAC) can be used to get rid of micropollutants in Samarra's drinking water. The effectiveness of GAC in adsorbing organic pollutants, such as medicines, insecticides, and industrial chemicals, is examined. The study talks about things that affect GAC performance, like contact time, pH, and dissolved organic matter (DOM). It also looks at advanced methods like ozonation and biological activation to make GAC work better, which could lead to better water quality in Samarra
The Effect of Different Service Loads on the Behavior of Full-Scale Precast Concrete Sandwich Panels
No full textThis research aims to develop low-cost and light-weight precast concrete sandwich panels (PCSPs) suitable for the limited loads they may be applied in the future applications, such as lightweight roofing panels. The mixture of concrete was designed to accomplish light weight and ease of workability. Self-compacting concrete (SCC) was used, containing 850 kg/mm of sand and 500 kg/m3 of cement at a water-to-cement ratio of 0.35, with the addition of a superplasticizer at 1% by weight of cement. A full-scale panel was examined with dimensions of 4.5 m length , 1 m in width and thickness of 0.13m The bottom layer of PCSP reinforced with a 2.15 mm steel mesh with 32 × 32 mm openings, the top layer reinforced with chicken wire, and the insulation layer made of expanded polystyrene (EPS) insulation. The two concrete layers were connected using 1.47 mm diameter steel mesh shear connectors grids distributed in five locations along the specimen to ensure composite bonding between the layers. Five major flexural tests were conducted on the panels under graded loads of 250 kg stimulation to examine the behavior of the panel to withstand dead loads, 100 kg, 200 kg of person's weights and 1000 kg to represent different loading levels. Vertical displacements were measured using LVDTs located at specific positions along the specimen span. The results showed that increasing the load resulted in a significant increase in vertical deflections with near-linear behavior up to certain load limits. Then, flexural failure features (cracks) began to appear. The results also established that the mesh connectors performed effectively in maintaining composite behavior up to intermediate loading levels, while the degree of bonding decreased at higher loads (1000 kg). The study shows that the proposed structural system has acceptable proficiency for limited load bearing, with high light weight, making it suitable for economical precast roof applications in low-cost buildings