KONSTAN - JURNAL FISIKA DAN PENDIDIKAN FISIKA

Typology and Cognitive Function of Visual Representations in Android-Based Digital Physics Modules: A Content Analysis Study

2026-06-30T14:23:06+00:00

This study aims to identify the typology, functions, and cognitive appropriateness of visual representations in two Android-based digital physics modules — "Fisika 11 Merdeka" (Linear Studio Apps) and "Fisika Gelombang" (Qreatif) — using Levin’s visual function taxonomy and Mayer’s Cognitive Theory of Multimedia Learning (CTML) as analytical frameworks. Through a descriptive qualitative approach with systematic content analysis, data were collected via high-resolution screenshot documentation and structured coding sheets validated by two expert judges. Results reveal that "Fisika 11 Merdeka" is dominated by static visuals serving decorative (±35%), organizational (±25%), and representational (±30%) functions, with no dynamic or interactive representations found. In contrast, "Fisika Gelombang" optimizes Android’s technological affordances through dynamic simulations, interactive features, and application of the signaling principle, with the majority of visuals serving interpretational and transformational functions (±60%). Evaluation of CTML principles shows that both applications effectively apply spatial contiguity; however, both critically violate the coherence principle due to commercial advertisements that generate extraneous cognitive load. This study concludes that digital modules do not automatically guarantee learning quality; developers should shift from mere text digitization toward the optimal use of interactive visual representations free from distracting elements.

Statistical Analysis of Seismicity in West Sumatra (2015–2025) and Aftershock Decay of the 2009 Padang Earthquake Using Gutenberg–Richter and Omori–Utsu Laws

2026-07-04T00:59:14+00:00

Previous studies on seismicity in West Sumatra have generally focused either on frequency–magnitude distribution or aftershock decay separately, with limited integration of updated earthquake catalogs and combined statistical approaches. This study examines the seismicity of West Sumatra using the Gutenberg–Richter (GR) law and the Omori–Utsu aftershock decay model for the 30 September 2009 Padang earthquake. Earthquake catalogs from the United States Geological Survey (USGS) covering the last ten years and the aftershock sequence of the 2009 event were analyzed. The GR law was applied through cumulative frequency–magnitude distributions to estimate the a- and b-values, which represent seismic activity level and magnitude distribution. The Omori–Utsu model was used to determine the decay parameter p and the initial aftershock activity constant K. The results show a strong linear frequency–magnitude relationship with a relatively high b-value, indicating dominant small- to moderate-magnitude earthquakes and high seismicity. Aftershock activity follows the Omori–Utsu decay pattern with a moderately slow decay rate. These results emphasize the influence of subduction zone dynamics and provide important implications for earthquake hazard mitigation in West Sumatra. These results provide updated seismic parameters for West Sumatra, support regional seismic hazard modeling, and contribute to refining empirical parameter estimation for the Sunda subduction setting.

Validity of a Problem-Based Learning Science E-Module Integrated with Ethnophysics to Support Science Process Skills and Critical Thinking Abilities

2026-07-06T01:24:40+00:00

This study aimed to evaluate the validity of a Problem-Based Learning (PBL)-based science e-module integrated with the ethnophysical context of the Perang Ketupat tradition for teaching temperature and heat to support students' science process skills and critical thinking abilities. The study was motivated by the limited integration of Problem-Based Learning, ethnophysics, science process skills, and critical thinking within a single science e-module, as identified through a review of previous studies. This research employed the Research and Development (R&D) method using the Four-D (4D) model, consisting of the Define, Design, Develop, and Disseminate stages, but was limited to the Develop stage focusing on expert validation. The developed instructional package included the Learning Objectives Flow, teaching module, science e-module, Student Worksheets, science process skills assessment instrument, and critical thinking assessment instrument. Product validation was conducted by five purposively selected experts representing science and physics content, instructional design and Problem-Based Learning, ethnoscience, educational assessment, and language. The validation covered content, presentation, and language aspects and was analyzed using Aiken's V coefficient. The results showed that all developed products achieved valid criteria, with Aiken's V values of 0.93 for the ATP, 0.92 for the teaching module, 0.91 for the science e-module, 0.89 for the LKPD, 0.88 for the science process skills assessment instrument, and 0.89 for the critical thinking assessment instrument. These findings indicate that the developed instructional materials satisfy the required quality standards (valid) and are appropriate for subsequent practicality and effectiveness testing before wider classroom implementation.

Fabrication and Characterization of Eggshell-Derived Nano-CaO Thin Films as Anti-Reflective Coatings: Morphological and Optical Properties

2026-07-06T02:35:22+00:00

Light reflection from glass surfaces reduces the amount of solar radiation transmitted into photovoltaic devices, making transparent thin-film coatings an important approach for improving optical transmission. This study investigated the preparation of calcium oxide (CaO) thin films derived from waste chicken eggshells through a simple and sustainable synthesis route. Eggshell powders were calcined at temperatures ranging from 800 to 1100°C, and the resulting CaO was deposited onto glass substrates by spin coating using five precursor concentrations, followed by post-annealing at 300°C. FTIR and XRD analyses confirmed the gradual decomposition of CaCO₃ into crystalline CaO with increasing calcination temperature. The sample calcined at 1100°C exhibited higher crystallinity (80.86%) and a larger crystallite size (19.24 nm) than that calcined at 1000°C. SEM observations indicated that post-annealing reduced the film thickness and produced a more uniform surface morphology. UV–Vis measurements showed that the 0,05 M precursor concentration and has the average thickness of 18,92 nm yielded the highest optical transmittance. The thin film prepared from CaO calcined at 1100°C and post-annealed at 300°C achieved a maximum transmittance of approximately 88% in the visible region (400–900 nm), which was higher than that of the uncoated glass substrate (85%). These results indicate that thermal treatment and precursor concentration significantly influence the structural and optical properties of eggshell-derived CaO thin films, highlighting their potential as transparent coating materials for photovoltaic glass

Synchronization in Coupled Duffing Oscillators: Numerical Exploration using Exponential Time Differencing

2026-07-06T02:57:27+00:00

The regularity that emerges from the interaction between irregular components is one of the fundamental questions in nonlinear physics. In this study, we examine how two externally driven, coupled Duffing oscillators can achieve synchronization. To analyze the dynamics of this system, we use the second-order Exponential Time Differencing (ETD2) numerical method, which allows us to comprehensively map the parameter space by varying the coupling strength () and the driving force amplitude (). The results show that the synchronization process does not occur simply. The process only appears in a certain synchronization window at weak coupling (). Within this region, the most prominent behavior is Phase Synchronized Chaos, where both oscillators achieve perfect phase locking (Synchronization Index ), but their amplitudes remain chaotic and uncorrelated. We also find that the system is multistable, capable of exhibiting several different final states simultaneously. The boundaries between these basins of attraction are highly complex and exhibit fractal patterns, indicating extreme sensitivity to initial conditions. In other words, even if the system parameters remain constant, the final outcome remains difficult to predict. Overall, these findings provide a comprehensive picture of the dynamics of two coupled Duffing oscillators. The results highlight the balance between external driving forces, coupling strength, and intrinsic chaos that forms the basis for directed synchronization.