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.

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:

This study aimed to evaluate stress distribution around two and four implants supporting maxillary implant overdentures retained by locator attachments, comparing full and partial palatal coverage designs. Four identical acrylic models representing completely edentulous maxillary arches were fabricated and covered with polyvinyl siloxane impression material to simulate the oral mucosa overlying the residual ridge. The models were divided into two main groups according to the number of installed implants (two or four), and each group was further subdivided based on palatal design (full or partial palatal coverage). Locator abutments (female components) were secured to the implants using an abutment driver, after which the prosthetic frameworks were constructed. Four strain gauges were bonded to each implant fixture using strain gauge cement to record strain values. A LLOYD digital loading device was employed to apply controlled compressive loads, and the resulting stresses around the implants were measured for each configuration.

Statistical analysis revealed a significant difference in stress values between two-implant overdentures with full palatal coverage (30.64 ± 17.47 N/m × 10²) and those with partial palatal coverage (49.72 ± 23.17 N/m × 10²), with higher stresses observed in the partial coverage design. In contrast, although four-implant overdentures with partial palatal coverage (8.77 ± 4.54 N/m × 10²) demonstrated higher mean stress values than those with full palatal coverage (5.51 ± 3.83 N/m × 10²), this difference was not statistically significant.

Within the limitations of this in vitro study, full palatal coverage design resulted in lower stress values compared to partial palatal coverage in two-implant-supported maxillary overdentures. For four-implant-supported overdentures, full palatal coverage also showed lower stress values; however, the difference was not statistically significant.

This study compared the retention of polyamide clasps engaging porcelain-fused-to-metal and zirconia retainers with identical 0.50 mm undercuts in posterior free-end saddle maxillary removable partial dentures. Four standardized acrylic resin models simulating maxillary bilateral posterior edentulous with first premolar abutments were prepared to receive either porcelain-fused-to-metal or zirconia crowns incorporating mesial occlusal rest seats. Polyamide RPA clasps were fabricated using an injection molding technique and tested for retention using a universal testing machine at a crosshead speed of 5 mm/min. The mean retention force of polyamide clasps was 6.68 ± 2.59 N for zirconia crowns and 5.47 ± 2.27 N for porcelain-fused-to-metal crowns. The results demonstrated minimal loss of retention for polyamide clasps against both ceramic materials, with no significant difference in retention related to the type of ceramic retainer.

Abstract:

This study aimed to compare the amount of stress generated on two versus four implants with equator attachments in maxillary implant overdentures with palatal coverage and palateless designs. Four standardized educational edentulous maxillary models simulating bone type II were used. The models were divided into two main groups according to palatal design (palatal coverage and palateless), and each group was further subdivided based on the number of implants (two or four implants). In the two-implant subgroup, implants were placed bilaterally in the canine regions perpendicular to the residual ridge using a surgical stent, whereas in the four-implant subgroup, implants were installed bilaterally in the canine and second premolar regions. Equator attachments with appropriate cuff heights were selected, and framework patterns were constructed. Four strain gauges were cemented to each fixture using strain gauge cement. A LLOYD digital loading device was used to apply compressive loads to measure the resulting stresses around the implants for each attachment configuration. The results demonstrated a statistically significant difference between stresses on two implants with equator attachments (74.53 ± 35.9 N/m × 10²) and four implants with equator attachments (10.85 ± 10.81 N/m × 10²) within the same palatal coverage design. Similarly, a statistically significant difference was found between stresses on two implants with equator attachments (123.75 ± 44.60 N/m × 10²) and four implants with equator attachments (14.51 ± 14.60 N/m × 10²) within the same palateless design. It was concluded that stress on two implants with equator attachments was markedly greater in the palateless design compared with the palatal coverage design, whereas stress on four implants with equator attachments was slightly greater in the palateless design than in the palatal coverage design, with no statistically significant difference.