Hydroxyapatite (HAp) is a biomaterial containing calcium phosphate with the chemical formula which is similar to the structure of human bone, so it is good for the purpose of healing human bones and teeth. HAp synthesis has several methods that can affect the results of HAp synthesis, such as the method of mixing CaO with phosphate, namely mixing with ultrasonic machines and magnetic stirrers. However, the discussion about the difference of HAp results with the mixing method of ultrasonic machine and magnetic stirrer is still rarely done. Therefore, it is important to examine and compare the characteristics of HAp synthesized by ultrasonic and magnetic stirrer mixing. The result of XRD test shows that HA1 has a purity of weight percentage (wt.%) of HAp crystal of 99.8%, while HA2 has a weight percentage (wt.%) of HAp crystal of 97.7%. For the FTIR test results of both specimens detected the presence of phosphate groups, and hydoxide, where both are the basic form of hydroxyapatite. Carbonate groups were also detected in the test, but it cannot be said to be bad because carbonate is a natural substitute for phosphate. 

A significant challenge in contemporary education is the limited understanding of technical subjects by students, such as the starter system within the Automotive Engineering program. The use of less engaging learning media leads to a decrease in student motivation, which ultimately affects academic performance. This study investigates the impact of an e-module, designed with Flipbook Maker, on student comprehension of the starter system. A quantitative approach was employed, utilizing pretests and posttests, along with surveys distributed to measure changes in understanding and student responses to digital learning media. The collected data was analyzed using simple linear regression through the SPSS software. The study involved a sample of 70 students from the XI grade of the Automotive Engineering program at SMK Negeri 1 Kandeman. The results revealed that the use of the e-module significantly improved student understanding, with a correlation coefficient (R) of 0.469 and an effect size (R Square) of 0.673, indicating that 67.3% of the variance in understanding was explained by the e-module. In conclusion, the e-module effectively enhanced student comprehension of the starter system. Students expressed a preference for digital learning media due to its flexibility in being accessed anytime and anywhere, both online and offline.

The automatic light sensor switch commonly used in the Electrical Power Installation Engineering Department at SMK Negeri 1 Tonjong is a factory-manufactured sensor switch with a complex circuit design, which has led to a decline in student learning motivation. This issue becomes the main reason for conducting research on the development of an instructional model for electrical lighting installations using a TRIAC-based light sensor switch, specifically applied in smart building lighting systems. This study employed a Research and Development (R&D) approach using the ADDIE development model. The findings of the study are as follows: (1) The developed product was deemed suitable for use, with a Content Validity Index (CVI) score of 0.88 from media experts and a Percentage of Agreement (PA) of 88%, and a CVI score of 0.91 and PA of 91% from subject material experts; (2) Product testing results indicated a high level of effectiveness, as shown by the Independent Sample t-Test on the N-gain Score, yielding a significance value (Sig. 2-tailed) of 0.000 < 0.05; and (3) The reproducibility coefficient (Kr) and scalability coefficient (Ks) were 92% and 81.5%, respectively, indicating that the instructional model for electrical lighting installation using the TRIAC-based light sensor switch is highly practical .

Limited understanding of 2D and 3D sketching using Autodesk Inventor Drawing, constrained by conventional teaching methods and the lack of adequate learning modules, remains a significant challenge in the manufacturing design course for Mechanical Engineering students at SMK Negeri 5 Semarang. This issue directly impacts student learning outcomes. This study aims to develop a flipbook-based e-module to improve learning achievements, with its effectiveness analyzed through t-tests and N-gain tests. The research employed the ADDIE development model (Analysis, Design, Development, Implementation, and Evaluation). An experimental method was applied using a pretest-posttest control group design, involving 64 students divided into an experimental class and a control class. The results indicated that the developed e-module, including its content, media, and assessment instruments, was deemed feasible for use. Statistical analysis revealed a significant improvement in the experimental class compared to the control class, as evidenced by a t-value greater than the critical t-table value (7.664 > 1.998). Furthermore, the N-gain test showed a moderate increase in the experimental class (0.56) compared to the control class (0.32), demonstrating an enhancement in student learning outcomes. This study highlights the positive impact of integrating technology into education and emphasizes the importance of innovative teaching methods in advancing student competencies in manufacturing design.