The purpose of this study is to analyze and demonstrate step-by-step bibliometric data analysis using VOSViewer completely and systematically. Step-by-step analysis was provided to make first-time users easily following the way how to use VOSviewers. This report allows and provides an easy way of data analysis by utilizing mapping tools and provide analysis of research developments regarding digital learning media. The method used in this research is to perform bibliometric analysis to produce network visualization of co-work maps and density maps of co-works. The analysis was carried out with the number of publications obtained, relating to the predetermined topics totaling 88 documents in 2017-2021. As practical examples, we evaluated the analysis of digital learning articles in pre and post covid. We found that VOSviewer can be used to give suggestions in the data analysis results.

This study aims to analyze the scope of research on materials using a bibliometric review and data mapping process. Research data on materials were obtained from databases from selected journals in Indonesia. The search is done using a search engine that contains data on all related journal articles. The search process is based on a topic area with titles, keywords, and abstracts in the study material. The mapping process is done using VOSviewer. A total of 60 relevant articles were found. The results showed that the most studied study material was in the 2016-2021 range. Meanwhile, in the field of chemistry, the “acid” term is the most widely discussed material. Among all contributing countries, Indonesia is the largest country with 43 articles. Indonesia also has the most links with other countries, namely 8 links. Through VOSviewer we analyze how many articles have been published about the material and its relation to the topic area. This review can certainly provide a reference point for further research related to materials.

X-Ray Diffraction (XRD) has been developed to analyze a crystal structure in the material. XRD is then improved for determining and identifying the presence of a compound, crystallinity, and crystal properties. XRD works by observing the ray refraction pattern as a result of the beam being refracted by a material that has an atomic arrangement in its crystal lattice. Until now, there is less information regarding detailed information on how to read the XRD spectrum and peak. This study aims to demonstrate how to calculate and interpret the crystallite size based on the XRD spectra. The step-by-step method in the calculation based on the XRD data is presented, which can help especially students and first-time users in understanding XRD results. This study is prospective to be used as standard information on how to read and interpret XRD spectra.

The purpose of this study was to find out collaborative practicum using conventional learning methods and experimental demonstrations to teach the concept of bioplastics fabrication to vocational students. Understanding bioplastics is good to possess the young generation, especially facing Sustainability Development Goals (SDGs). The subjects of this study were 40 students of class XI in vocational schools which were divided into two classes, namely the control and the experimental classes. Treatment given to experimental class was by providing learning with an experimental demonstration using learning videos, while control class learning was done using conventional teaching method. Learning outcomes of both classes were evaluated from the pre-test and post-test scores as well as the N-Gain value. The data analysis technique used was the analytical technique of descriptive data, including the mean and standard deviation. The analysis requirement test was carried out using a normality test. To test the hypothesis of differences in student learning outcomes, a non-parametric test was used. Based on descriptive analysis, learning outcomes with the experimental demonstration method are more effective than that with the conventional method. This result is evidenced by the experimental class's N-Gain value which is greater than those of the control class. The results were also confirmed by statistical analysis using the Mann-Whitney non-parametric test, showing a significant difference in learning outcomes between the control and the experimental classes. In short, the results of the study showed an increase in achievement and significant student learning using the experimental demonstration method. The experimental demonstrations using available materials make students more interactive because students want to try the process by themselves. Using the experimental demonstration method, students are expected to be able to find, prepare, and carry out the learning process. Thus, students get good learning outcomes. This study is expected to have an impact on the further teaching of experimental demonstration research which is believed to provide good learning success for students.

The objective of this study is to develop a new environmentally-friendly brake pad made from eggshells (Es) and banana peels (BPs) as reinforcement agents. E and BP particles as dual reinforcement with various compositions were combined. The E/BP mixture was then embedded on a polymer matrix composing a resin/hardener mixture in a 1:1 ratio. As a standard, brake pads using a single reinforcement of E and BP particles were also fabricated. Physical properties (i.e. particle size, surface roughness, morphology, and density), as well as mechanical properties (i.e. hardness, wear rate, and friction coefficient properties) were investigated. It was observed that using dual reinforcements was preferable (compared to using single reinforcements) because they had a synergistic effect on the mechanical properties of the brake pad. The best mechanical properties were found in dual reinforcements of brake pad specimens using E/BP particles with a higher BP ratio in which the value of the stiffness test, puncture test, wear rate, and coefficient of friction were 4.5 MPa, 86.80, 0.093×10-4 g/s.mm2, and 1.67×10-4, respectively. A high BP particle ratio played a dominant role in dual reinforcements, increasing the resin's bonding ability and resulting in good adhesion between the reinforcement and matrix. When compared to commercial brake pads, the brake pad specimens fabricated in this study met the standards. The techno-economic analysis also confirmed the prospective production of brake pads from E and BP particles (compared to commercial brake pads). From this research, it is expected that environmentally friendly and low-cost brake pads can be used to replace the dangerous friction materials.