Search

Phosphocalcic apatites have osteoconductive and bioactive properties that make them suitable for bone reconstruction. But, they are inactive against pathogenic microorganisms that can infect bone tissue. To overcome this limitation, we synthesized oxygen-doped phosphocalcic apatites that can release molecular oxygen as a bioactive molecule. We investigated how the calcium-to-phosphorus ratio (Ca/P) gave impacts on the chemical and structural composition of the oxygen-doped phosphocalcic apatites. We here used the double decomposition method, which involved mixing calcium nitrate and diammonium phosphate solutions in an ammonia buffer. We then characterized the products using several analysis, including infrared absorption spectroscopy, X-ray diffraction, thermal analysis, nitrogen adsorption-desorption, and elemental chemical analysis. It was found that the oxygen-doped phosphocalcic apatites were calcium-deficient and had a well-defined crystallinity at room temperature. After calcination at 900°C, the crystallinity improved further. The thermal analysis showed two mass losses: one at 50°C due to water adsorption and another at 450°C due to CO2 release. The specific surface area was about 100 ± 2 m2/g without any change with the Ca/P ratio. The quantity of molecular oxygen increased with the Ca/P ratio and reached an optimal value of the order of 3.6 ×10-4 mol for Ca/P=1/65 with the chemical formula of Ca9.9(PO4)6(OH)1.25(O2)0.74(CO3)0.01. It is important to make further analysis to know more about the properties of oxygenated apatite, and to combine this apatite with polymers purposely to have biomedical composites. It then can be concluded that the oxygen-doped phosphocalcic apatites could be a promising biomaterial for bone infection prevention and treatment. This research highlights an oxygenation treatment of phosphocalcic apatite and brings new ideas and possibilities for future research and development to get better understanding of the behavior of these biomaterials to be more effective, especially in the biological field. As a perspective, improving the biological properties in these biomaterials needs to be further explored, including experimental parameters for the obtainment of more conclusive results.

This research aims to determine the development of the number of scientific publications in the field of particulate matter; the number of publications from each country that publish articles on heat transfer, nanoparticles, and automotive radiators; articles with the highest number of citations; and visualization publication development map based on keywords. To achieve this goal, quantitative descriptive research was carried out using bibliometric analysis with the help of the publish or perish (PoP) application to collect data and VOSviewer to visualize related research topics. The article data taken is limited to 2018-2023. In addition, the terms heat transfer, nanoparticles, and automotive radiators are used as keywords in collecting article data using the pop application. Research on heat transfer, nanoparticles, and automotive radiators has increased in 2020 and India has become one of the countries that has contributed many publications on this topic. From the mapping results, research on heat transfer, nanoparticles, and automotive radiators is still being carried out frequently, especially in early 2020-2021. This research can help academics determine which problems to research and can be used as a reference for further research.

This study aims to determine the knowledge and understanding of elementary school students about nutritious food and fast food, as well as recommendations for balancing them. The method used is a quantitative method with an experimental research design. The intended target is elementary school students in grade 5. The subject is 20 students in one class. The research was carried out in 3 stages, (i) pre-test, (ii) education using lecture and picture methods about fast food and healthy food, and the last one was (iii) post-test were the questions given were the same questions as the pre-test. After being educated about healthy nutritious food and fast food, the results showed quite different results from the previous results, which increased by 9% from 71.25 to 81.25%. The ineffectiveness of this method was influenced by the pretest scores of respondents which are already large enough. Thus, the increase is not so large. With the results obtained from the research that has been carried out, it is hoped that school-age children can be better informed about the importance of a balanced intake of healthy food and fast food consumed by children.

This study aims to develop asbestos-free and environmentally friendly brake pads using apus bamboo powder (Gigantochloa apus). In the experiments, bamboo powder, resin, and catalyst were used as the raw materials and varied to ensure the quality of the prepared brake pads. To analyze the performance of brake pads, the fabricated brake pads are subjected to physicochemical tests (such as microscopic tests and functional group analysis) and mechanical tests (such as puncture tests, compression tests, and friction tests). The research results showed that adjusting the composition of the raw materials allowed a change in the performance of the brake pad, including porosity, morphological structure, and mechanical properties. Indeed, the condition of the low porosity on the inside of the brake pad strategically optimizes the compression strength of the material, making this design ideal for applications that require high resistance to compression loads. This study shows the possibility of apus bamboo powder as an alternative to asbestos in the production of non-asbestos brake pads, offering a safer and environmentally friendly solution as well as giving ideas for supporting current issues in the sustainable development goals (SDGs).