Graphene oxide (GO) based on coconut shell waste was successfully synthesized using a modified Hummers method, and the obtained GO was confirmed using XRD, FTIR, Raman spectroscopy, UV-Vis spectroscopy, and SEM-EDX. The XRD spectroscopy obtained the fractional content of the 2H graphite phase of 71.53%, 14.47% phosphorus, 10.02% calcium, and 3.97% potassium in coconut shell charcoal, where the GO sample tend to forms a phase of reduced graphene oxide (rGO). FTIR spectra shows compound functional groups of hydroxyl (- OH) at peak 1 (3449.92 cm
−1
), carboxyl (-COOH) at peak 2 (1719.42 cm
−1
) and peak 3 (1702.62 cm
−1
), and alcohol (C–OH) at peak 4 (1628.12 cm
−1
) and epoxy (CO) at peak 5 (1158.51 cm
−1
), which is similar to the GO synthesis from pure graphite. Raman spectroscopy analysis shows that the value of the I
D
/I
G
intensity ratio of the GO sample was 0.89 with a 2D single layer, and SEM results showed that surface morphology with an abundance of granular particles were found with different size distribution. The UV-visible results showed sufficient optical properties characterized by the spectrum, which formed because of the light absorption of the energy passed on the sample. The bandgap energy value of the sample obtained by the Tauc plot method was 4.38 eV, which indicates semiconductor properties.
This research was a descriptive case study. The purpose of this research was to describe the student’s ability to interpret the kinematics graph. The subjects of the study were 347 students of class XI science in the even semester of 2018/2019 in Luwu Raya, South Sulawesi Province, Indonesia. The research data were obtained from multiple-choice test results using instruments adapted from Test of Understanding Graph – Kinematics 2.6 and the results of in-depth interviews to find out the reasons learners choose answers and casual factors. The results of the study based on descriptive data analysis were 90 students or 25.94% in the low category, and 257 students or 74.06% were in the very low category. These results indicate the ability to interpret the graphs of students were still low, with the average achievement in answering questions on each of the highest indicators was 20.99 % on indicators identifying graphs based on the description. While the lowest average achievement was11.91%, which is the indicator to identify the graph that has a different variable. Base on the qualitative data analysis, the results are students had difficulties in solving the test, as follows: a) the difficulty in distinguishing symbol of the variables on the graph, b) the difficulty in determining the formula for solving test in graphical form, c) to determine when the curve on the graph v-t decreases then the object will move with speed slowed. The factors causing these difficulties are because students did not understand deeply about how to read graphs, how to solve test in graphical form, and did not understand the formula used to solve the test.
This research aims to examine and analyze the implementers disposition in the implementation of teacher certification policy in Makassar City and to know how is the disposition affects in successful implementation policy. This research is descriptive by using a qualitative approach. Sources of data in this study are primary data from the informants and secondary data using library research. This research used qualitative methods so that researcher as the manager of the research to be one of the instruments for collecting data, and also as the key instrument. Data was gathered by way of interviews, observation, and documentation. The results of research showed that the attitude of the implementer requiring payment of the certification candidate is not in accordance with the rules that apply in the recruitment of candidates for certification, and the issue has an effect of the implementation on successfully teacher certification policy. The implementers policy must follow procedure in accordance with the established guidelines or regulations.
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