Polyvinylpyrrolidone (PVP; poly(N-vinylpyrrolidone)) is a versatile water-soluble polymer widely used in pharmaceuticals, coatings, and nanocomposites due to its solubility, biocompatibility, and film-forming properties. Despite its extensive applications, systematic kinetic data describing its thermal degradation remain limited. In this study, non-isothermal thermogravimetric analysis (TGA) of PVP was performed under nitrogen and air atmospheres at heating rates of 5, 10, 20, and 40 °C min⁻¹. Thermal profiles revealed three degradation stages: moisture loss (30–150 °C), main-chain scission and depolymerization (150–450 °C), and carbonaceous residue formation (>450 °C), with the principal decomposition peak at 370–410 °C. Activation energies (Eₐ) determined using Kissinger, Flynn–Wall–Ozawa (FWO), and Kissinger–Akahira–Sunose (KAS) methods ranged from 179 to 186 kJ mol⁻¹ and were validated using the Coats–Redfern model-fitting approach. Reaction orders (n ≈ 1.1–1.3) indicate random chain scission as the dominant mechanism. The resulting kinetic dataset provides reliable insight into PVP thermal stability and supports optimization of processing, recycling, and composite fabrication.

Thermal decomposition analysis is fundamental for evaluating the stability, degradation pathways, and safety profile of materials exposed to elevated temperatures. Thermogravimetric analysis (TG) provides quantitative information on mass loss, while Fourier-transform infrared spectroscopy (FTIR) identifies evolved gaseous products. The coupling of TG with FTIR (TG–FTIR) offers a comprehensive analytical platform capable of correlating weight-loss events with chemical species released during thermal degradation. This integrated technique has gained increasing importance in polymer science and pharmaceutical research. Selected polymeric and pharmaceutical samples were subjected to TG–FTIR analysis under a nitrogen atmosphere. Approximately 8–10 mg of each sample was heated from 25°C to 800°C at a constant heating rate of 10°C/min. The evolved gases were transferred through a heated interface to the FTIR gas cell to prevent condensation. TG and DTG curves were recorded and synchronized with FTIR spectra to identify volatile degradation products and correlate them with specific thermal events. Distinct multi-stage decomposition patterns were observed for all samples. Polymeric materials demonstrated higher onset degradation temperatures compared to pharmaceutical compounds. FTIR analysis revealed the evolution of CO₂, CO, H₂O, and volatile organic compounds at characteristic temperatures corresponding to dehydration, bond cleavage, and oxidative degradation phases. The integration of TG and FTIR data enabled accurate identification of decomposition pathways and estimation of kinetic parameters. TG–FTIR coupling provides a robust and informative technique for comprehensive thermal characterization. The method enhances mechanistic understanding of degradation behavior and supports the development of thermally stable materials in industrial and pharmaceutical applications.

Abstract

Developing reading proficiency is essential for mastering English as a Foreign Language (EFL), yet many learners encounter difficulties due to restricted vocabulary and a lack of contextual understanding. To mitigate these issues, educators often suggest using picture books, which integrate visual imagery with text to help students decode meaning through multiple channels.

This study examines the influence of illustrated books on EFL reading comprehension using a quasi-experimental framework. The research involved 30 primary school pupils, divided into an experimental group using picture books and a control group receiving standard instruction. Results from pre- and post-test evaluations showed that students in the experimental group made significantly more progress than those in the control group.

These outcomes suggest that picture books are a powerful resource for enhancing comprehension and learner interest. Based on these findings, this study recommends EFL teachers incorporate  illustrated materials into their lessons  to enhance students’ understanding and engagement.

Keywords: picture books, reading comprehension, EFL learners, visual learning, young learners, language teaching.

This paper presents a comprehensive analysis of load expansion planning through the integration of photovoltaic systems at the Bir Alganame 220/30 kV substation. An electrical planning system serves as a crucial tool for designing electrical systems that effectively meet evolving energy demands. The study investigates the impact of load expansion on hybrid photovoltaic system design, focusing on system reliability and total project cost as primary design objectives. The research methodology encompasses a detailed load flow study conducted in 2024, coupled with load forecasting for 5 and 10-year horizons at an 8% load increase rate. The investigation includes analyzing the optimal parameters of the PV system integration with the existing grid to ensure proper functionality. Additionally, the study addresses the probabilistic scenario set of load demand and natural characteristics of renewable energy, which is crucial for power system planning studies. The research emphasizes the importance of proper transmission system network development to reliably and securely evacuate the generated power to meet future domestic load demand. Through simulation and analysis, this study demonstrates an integrated approach to improving power system performance while considering geographical and environmental factors affecting PV output. The findings provide valuable insights into optimal electrical network planning procedures, incorporating both long and short-term perspectives through PV system integration.

Abstract

Vocabulary acquisition is a cornerstone of foreign language development, yet traditional instructional methods often fail to engage young learners or support long-term retention. This study investigates the effectiveness of using songs as a pedagogical tool for teaching English vocabulary to young English as a Foreign Language (EFL) learners. Employing a quasi-experimental quantitative design, the research compares the vocabulary acquisition of a group of primary school students (aged 6–10) instructed through songs with a control group receiving conventional instruction. Data were collected through pre- and post-tests, classroom observations and teacher feedback. The findings reveal that the experimental group demonstrated significantly greater improvement in vocabulary retention and recall compared to the control group. Furthermore, students in the song-based group exhibited higher levels of motivation, engagement and improved pronunciation. The study concludes that integrating songs into EFL instruction creates an interactive, stimulating and low-anxiety learning environment, making it a highly effective strategy for enhancing vocabulary acquisition among young learners.

Keywords: vocabulary acquisition, songs, young EFL learners, music-based instruction, vocabulary retention