Abstract:

This study assesses the implementation level of the Occupational Health and Safety Management System (OHSMS) based on ISO 45001:2018 at Brega Oil Marketing Company (BOMC), Libya. A quantitative descriptive methodology was employed using a structured questionnaire derived from ISO 45001 clauses. Data were collected from 60 employees across four operational sites and analyzed using descriptive statistics in IBM SPSS. The results indicate partial compliance with ISO 45001 requirements (mean ≈ 3.82). Strong performance was observed in safety awareness and employee satisfaction, whereas weaknesses were identified in planning, hazard identification, and performance evaluation processes. The study recommends strengthening risk-based planning and internal auditing mechanisms to improve system effectiveness and ensure continual improvement.

Keywords: Occupational Health and Safety, ISO 45001, Gap Analysis, Oil and Gas Industry, Brega Oil Marketing Company. 

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

Polyvinylpyrrolidone (PVP) is a widely used water-soluble polymer with applications in pharmaceuticals, cosmetics, adhesives, and medical devices. Despite its versatility, the thermal stability of PVP remains a concern during processing and high-temperature applications, where degradation can compromise performance and safety. This study aimed to investigate the kinetic parameters of PVP thermal degradation using isothermal thermogravimetric analysis (TGA) over a temperature range of 30–800 °C. PVP samples were analyzed under a nitrogen atmosphere, and weight loss was recorded over time. Kinetic parameters, including activation energy (Ea) and pre-exponential factor (A), were determined, and molecular weight changes were evaluated via gel permeation chromatography. Results indicated multi-stage degradation with increasing Ea at higher temperatures, consistent with backbone scission and pyrrolidone ring decomposition. Molecular weight decreased progressively, and polydispersity increased, reflecting chain fragmentation. The study provides accurate isothermal kinetic data, contributing to better prediction of PVP behavior under thermal stress and guiding the design of thermally stable formulations

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.