Samudra University (Indonesian: Universitas Samudra, abbreviated Unsam) is an Indonesian public university in the city of Langsa, Aceh. Initially an affiliate of the Syiah Kuala University, the university separated into its own organization in 1985 and was nationalized in 2013. The university possessed five faculties and 9,879 active students in 2014.
This study investigates the catalytic specificity of sulfonated palm kernel shell (PKS)-derived biochar for the esterification of free fatty acids (FFA) in high-acid crude palm oil (HACPO). Biochar was prepared by pyrolysis (500 °C, 5 h, N2), activated with KOH (2 M, 1:4 w/v, 90 °C, 5 h) and HCl (1 M, 1:4 w/v), and sulfonated with concentrated H2SO4 (1:4 mass ratio, 100 °C, 5 h). Comprehensive characterization using FTIR, XPS, XRD, and N2 physisorption revealed that KOH activation generated substantial microporosity (BET surface area 251.85 m2/g), which was subsequently blocked by the grafted –SO3H groups after sulfonation, causing the surface area to collapse to 4.95 m2/g. XPS confirmed the exclusive presence of covalently bound aromatic –SO3H groups (S 2p at 168.7 eV) with no residual sulfate impurities. The resulting catalyst exhibited a competitive acid site density of 2.80 mmol g⁻1 and achieved an 84.44
The high content of free fatty acids (FFA) in vegetable oils, such as oleic acid, requires an effective acid catalyst for the esterification process in biodiesel production. This investigation endeavors to synthesize sulfonated polystyrene-divinylbenzene resin (PS-DVB-S) as a heterogeneous catalyst through the polymerization of styrene and divinylbenzene, succeeded by sulfonation to yield solid acid catalyst properties. Characterization was conducted via Fourier Transform Infrared Spectroscopy (FTIR), which confirmed the successful sulfonation through the detection of the – SO3H group absorption band within the range of 1018–1021 cm⁻¹, in contrast, thermogravimetric analysis (TGA) indicates that increasing the concentration of sulfonic acid groups reduces the thermal stability of the resin at elevated temperatures. The catalytic activity assessment in the oleic acid esterification reaction effectively diminished the acid number of oleic acid from 199.71 mg KOH/g to 20.78 mg KOH/g when utilizing the PS-DVB-S/D catalyst, achieving the highest FFA conversion rate of 89.59
In particle physics, as in many areas of science, parameter inference relies on simulations to bridge the gap between theory and experiment. Recent developments in simulation-based inference have boosted the sensitivity of analyses; however, biases induced by simulation-data mismodeling can be difficult to control within standard inference pipelines. In this work, we propose a Template-Adapted Mixture Model to confront this problem in the context of signal fraction estimation: inferring the population proportion of signal in a mixed sample of signal and background, both of which follow arbitrarily complex distributions. We harness many biased simulations to perform data-driven estimates of each process distribution in the signal region, substantially reducing the bias on the signal fraction due to the domain shift between simulation and reality. We explore different methodological choices, including model selection, feature representation, and statistical method, and apply them to a Gaussian toy example and to a semi-realistic di-Higgs measurement. We find that the presented methods successfully leverage the biased simulations to provide estimates with well-calibrated uncertainties.
This study investigates the index of cultural and civic literacy among elementary school students in Langsa City, one of the most multicultural areas in Aceh Province, Indonesia. Using a mixed-methods, sequential, explanatory design, the research combined quantitative analysis of electronic education reports (e-raports) with qualitative exploration through interviews, observations, and document analysis. The quantitative findings revealed that of the four sample schools, two were categorised as moderate (yellow) and two as low (red), with an average index of 61.94%. These results indicate that students' mastery of cultural and civic literacy remains relatively low. The qualitative analysis highlighted several constraints in implementing the Projek Penguatan Profil Pelajar Pancasila (P5), including limited teacher training, a lack of thematic modules, and insufficient integration of local culture into learning activities. Schools predominantly adopted themes such as Entrepreneurship and Sustainable Lifestyle, while essential themes related to multicultural values, such as Bhinneka Tunggal Ika and Build Body and Soul, were not implemented. This study emphasises that, despite Langsa's rich cultural diversity, schools have yet to leverage local wisdom as a learning resource fully. The findings contribute to the discourse on cultural literacy by revealing paradoxes in multicultural contexts and provide practical recommendations for policymakers, educators, and local stakeholders to strengthen cultural and civic literacy as a foundation for social cohesion and national identity.
Purpose of Study: This study aims to examine the effectiveness of Nearpod-based training in improving the Technological Pedagogical Content Knowledge (TPACK) competence of prospective physics teachers in designing physics learning tools.Methodology: This study employed a quantitative approach with two analytical components. The first component used a One-Group Pretest–Posttest design involving 19 prospective physics teachers who participated in Nearpod-based training and teaching simulations. The second component involved a final TPACK questionnaire administered to 60 prospective physics teachers from four universities. Data were analyzed using N-Gain, the Wilcoxon Signed-Rank Test, and the Rasch Model with Winsteps software. Main Findings: The results showed that the mean TPACK score increased from 76.05 in the pre-test to 91.50 in the post-test, with an N-Gain value of 0.65, indicating moderate improvement. The Wilcoxon test produced a significance value of 0.000, confirming a statistically significant difference between pre-test and post-test scores. Rasch analysis showed that 85% of respondents were in the moderate TPACK category. The Wright Map further indicated that Technological Knowledge, Content Knowledge, and some aspects of Pedagogical Knowledge were relatively easier to master, whereas Pedagogical Content Knowledge, Technological Pedagogical Knowledge, and holistic TPACK remained more challenging.Novelty/Originality of This Study: This study highlights Nearpod not only as a digital learning platform, but also as a pedagogical design space that supports prospective physics teachers in integrating physics content, interactive digital features, formative assessment, student engagement, and feedback within technology-enhanced learning.
