Jurnal Pendidikan Teknologi Kejuruan

Revolutionizing polymethyl methacrylate toughness: Achieving 190% improvement with nanocellulose reinforcement while maintaining optical clarity

2024-10-22T10:16:23+00:00

Polymethyl methacrylate (PMMA) is widely used in applications requiring high transparency and durability, such as optical lenses and protective coatings. However, its inherent brittleness limits its application in high-impact environments. This study investigates the incorporation of cellulose nanocrystals (CNCs) into PMMA to significantly enhance its toughness without compromising its optical clarity. By reinforcing PMMA with CNCs, the nanocomposites exhibited a remarkable 190% increase in toughness while maintaining 90% optical transparency. The innovation lies in achieving a balance between toughness and transparency through controlled CNC dispersion within the PMMA matrix, which minimizes excessive bonding that could lead to brittleness. Proper CNC dispersion was achieved through in-situ polymerization, allowing the nanocrystals to interact with the polymer matrix through van der Waals forces rather than covalent bonds. This approach reduces stress concentration and mitigates the formation of defects in the polymer matrix, ultimately leading to a tougher, more flexible material. In addition to enhancing mechanical properties, this study underscores the importance of controlling CNC content to preserve the intrinsic optical transparency of PMMA. These findings open new possibilities for CNC-reinforced PMMA in advanced applications that demand high mechanical performance coupled with excellent optical properties, extending its use in fields such as medical devices, protective coatings, and transparent structural materials.

Modified sorbents based on natural mineral and its mechanical properties

2024-10-01T05:10:35+00:00

The use of modified sorbents based on natural minerals, widely distributed in Kazakhstan, is a promising direction. This direction is related to the development of domestic ion-exchange materials. The republic lacks its own production of synthetic sorbents. The environmental situation in the regions of uranium ore mining and processing is also important. Moreover, the application of synthetic sorbents is not always justified due to their high cost, while the use of natural sorbents is limited by their low sorption capacity. The development of modified ion-exchange materials based on a combination of these is a pressing issue for various industries. Research has been conducted on the choice of modification methods for natural sorbents and the evaluation of their sorption capacity after modification. The modification of natural minerals zeolite and shungite using the "solid-phase extractants" method was carried out in two stages. At the first stage, the modification was performed with organic extractants and compositions based on them, and at the second stage with phosphoric acid in combination with polyacrylamide. The natural sorbents used were zeolite from the Kusmuryn deposit and shungite from the Koksu deposit, following preliminary flotation. The mechanical strength of sorbents modified by different methods was compared with the original ion-exchange materials. Studies of the sorption process have shown that the best results for uranium sorption were obtained with modified sorbents: zeolite modified with a mixture of extractants Di-2-Ethylhexyl phosphoric acid (Di-2-EHPA), Tributyl phosphate (TBP), kerosene, and shungite modified with phosphoric acid in the presence of Polyacrylamide (PAA).

The freedom to learn-independent campus curriculum for shielded metal arc welding: A teaching module development

2024-11-03T04:27:07+00:00

This study was triggered by the existing teaching modules for the Shielded Metal Arc Welding (SMAW) subjects taught at vocational high schools, which do not align with the Freedom to Learn-Independent Campus (FLIC) learning objectives, and do not provide a systematic organization. In order to enhance the learning experience, this research developed a new learning module that integrated Problem-based Learning (PBL), promoting critical thinking, and the practical application of theoretical concepts, following the FLIC curriculum. Utilizing a Research and Development (R&D) approach with the Instructional Design Institute (IDI) model, this study involved two welding instructors and four lecturers as validators to assess the content and usability of the module. The IDI model comprised three steps: instructional (define), development (develop), and institute (evaluate). The research findings regarding the validity assessment by subject matter experts yielded a final validity score of 0.924, while media and language experts provided a score of 0.936, meeting the valid criteria. The practical usability test of the learning module resulted in a score of 94%, indicating that it is highly practical for students to use as learning media. Based on the validity and practicality assessments of the developed module, it can be concluded that the SMAW learning module is highly practical to use as teaching media, aligning with FLIC curriculum.

Integrating e-module craft and wedding gifts course; the effect on creative thinking and attitudes student in vocational education students

2024-10-22T09:52:26+00:00

Society 5.0 envisions a future that emphasizes the integration of advanced technologies with human life to foster a more human-centered, sustainable, and inclusive community. A key skill in this context is found in the craft and wedding gift course. This course not only equips students with comprehensive knowledge of crafting techniques for wedding gifts but also prepares them to engage in the rapidly expanding field of entrepreneurship. The objective of this study is to develop an e-module focused on teaching wedding gift-making skills for vocational students. This e-module will be tailored to fulfill students' needs for an interactive, engaging, and flexible learning experience. The research employs a development research (R&D) approach, aiming to enhance the quality of education by implementing the ADDIE model. The developed e-module received a very valid assessment, with 90.67% from the media validator and 90.25% from the material validator In addition, this e-module was also considered very practical by lecturers with a score of 85% and by students with a score of 92%. The decision-making criteria were if the sig value (2-tailed) <0.05, then the proposed hypothesis was accepted.

Learning media development of lighting simulator in electrical maintenance training course for vocational education

2024-11-04T14:35:25+00:00

This research aims to develop learning media for lighting systems in the form of lighting simulator to support learning in electrical maintenance training subjects. This research was conducted at the Motorcycle Engineering Department of SMKN 1 Pancung Soal. The main focus of this research is to assess the feasibility of learning media which is a lighting system simulator. It is a Research and Development, adopting the Four-D models introduced by Thiagarajan. The steps taken include define (defining or analysing problems to formulating development objectives), design (designing the media to be produced), develop (development is carried out after going through expert and user trials), and disseminate (dissemination which is introducing the media in training). The results of this research are in the form of learning media, supporting learning electrical maintenance training courses. The results of the feasibility testing on this lighting simulator in terms of media aspects scored 88% with the category ‘Very Decent’ and in the material aspect scored 84% with the category ‘Very Decent’. For the feasibility level, practitioners or users scored 89% which falls in the ‘Very Decent’ category. Based on the data from the feasibility test results conducted by experts, it can be concluded that this lighting system simulator is very feasible and can be used as a medium to support the implementation of the practicum of electrical maintenance training courses.