Search

Supercapacitors can be called electrostatic double-layer capacitors (EDLCs) or pseudo-capacitors based on their energy storage mechanism. Pseudo-capacitors with metal oxide electrodes that transmit electric charge offer great application power but low stability. This study aims to characterize trisodium citrate (TSC) modified NiCo2O4/rGO electrodes as a preliminary study for the NiCo2O4 nanoparticle pseudo-capacitor. The materials were characterized using SEM (Scanning Electron Microscopy), XRD (X-Ray Diffractometer), FT-Raman (Fourier Transform Raman Spectroscopy), and FTIR (Fourier Transform Infrared Spectroscopy). All of these analyses confirmed that NiCo2O4 was manufactured successfully using TSC. At XRD, the angles of 2????, namely 45.04 and 53.34°, matched the plane of the cubic phase nanorod crystals of NiCo2O4 with values of 400 and 511, respectively. In the Raman examination, the presence of rGO, which increased the crystallinity of NiCo2O4 nanoparticles, was confirmed. FTIR analysis indicated that the 1550-1600 cm−1 corresponds to a C=C functional group in an aromatic ring or a C=O ????-???? structure, and the wavenumber of 2300 cm−1 corresponds to the OH group in TSC, an alkanoate derivative. SEM analysis determined that NiCo2O4 nanoparticles with 1 mmol TSC are the ideal material for supercapacitor electrodes, as the structure is the most uniform, soft, and tidy. Further analysis is needed to confirm the stability of the modified material.

Implementing online learning in a higher education environment requires an analysis of learning outcomes and their impact on students, lecturers, and the institutions that administer the learning. The implementation of online learning shows that the learning process takes place and the readiness of lecturers and students to implement online learning. The impact given by online learning is in the form of GPA and student perceptions of the learning process they experience. Based on the research results, various findings were obtained, including that mastery of online learning LMS was not optimal, learning outcomes in the form of GPA were relatively high, students' perceptions of online learning were still low, especially in terms of lecturer readiness and students' confidence in their competence after participating in learning.

This study aims to determine the effect of using practicum tools with diferentiated learning strategies on student learning outcomes. The research method used is quasi-experimental design. The population in this study was all of class X MIA, totaling 212 students, of SMA Negeri 8 Medan. The research sampling technique is purposive sampling technique. Non-equivalent control group design is the type of the research design. The sample in the study consisted of an experimental class, namely class X MIA 6, and a control class, namely class X MIA 5. The experimental class was treated with differentiated learning strategies, while the control class was treated with conventional learning. The research instruments used were multiple-choice questions and student observation sheets. The average score of the posttest for the experimental class was 76.28 with a standard deviation of 6.9, and that of the control class was 72.08 with a standard deviation of 6.7. The pretest and posttest data obtained have been analyzed and met the prerequisites for testing the hypothesis, namely, the data is normally distributed and is homogeneous. The result of the right-tailed t-test on the hypothesis obtained the value of tcount > ttable, namely 2.608 > 2.002 whit = 0.05. Based on the testing criteria, the accepted hypothesis is H, which means that there is an effect of the treatment that is the use of practicum tool with different learning strategies on student learning outcomes at SMA Negeri 8 Medan for the 2022/2023 academic year. The result of the simple linear regression equation is Y = 65.9 + 0.34X.