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All Journal Natural B Momentum: Physics Education Journal
Ratri Andinisari
National Central University, Taiwan
Environmental Science Physics

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Preliminary Study on the Determination of Volcanic Tremor Epicenter Using Semblance Method (Case Study of Sakurajima Volcano) Ratri Andinisari; Sukir Maryanto; Ahmad Nadhir
Natural B, Journal of Health and Environmental Sciences Vol 2, No 2 (2013)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1878.07 KB) | DOI: 10.21776/ub.natural-b.2013.002.02.12

Abstract

Volcanic tremor is one of the most important volcanic activities due its strong connection to magma movement and impeding eruption. Therefore, the determination of volcanic tremor epicenter becomes very important. The absence of apparent P and S wave arrival of volcanic tremor is the main constraint of its epicenter determination. The use of semblance method is required because semblance method requires no information about P and S wave arrival in epicenter determination. A preliminary application of semblance method has been done to determine the epicenter of 100 s length volcanic tremor of Sakurajima volcano. In this research we use the recorded seismic signal from 5 different volcano observatories, which are KOM, KAB, HIK, ARI, and HAR. The recorded tremor signal is then analyzed by using semblance method. The analysis is carried out by calculated semblance coefficient in every 30 s moving window along the signal. The resulting semblance coefficient varied from 0,25 to 0,42. The epicenter of observed volcanic tremor is located in the north-east part of Minamidake crater by -18,66o to 54,10o of azimuth counted from the east, while the epicentral distance of the observed volcanic tremor varied from 608,28 to 948,68 m from Minamidake crater.
JITT with assessment for learning: Investigation and improvement of students understanding of kinematics concept Akhmad Jufriadi; Ratri Andinisari
Momentum: Physics Education Journal Vol 4 No 2 (2020)
Publisher : Universitas PGRI Kanjuruhan Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21067/mpej.v4i2.4669

Abstract

This study aims to investigate and explore students' understanding of the concept of Kinematics, particularly in the concepts of acceleration, velocity, distance and displacement. This research used a mixed-method approach with an embedded experimental design. The research was conducted by involving 21 students consisting of 7 men and 14 women. This research used reasoned multiple-choice questions and short interviews to determine the students' initial and final understanding. The results showed that, before the intervention was carried out, as much as 42.86% of students did not understand the concept of distance and displacement correctly, as much as 26.99% of students did not understand the concepts of instantaneous velocity and average speed, as much as 45.6% did not understand the concepts of position, velocity and acceleration and as much as 87.31% did not understand about the direction of velocity and acceleration. In addition, the results showed that the application of JITT with assessment for learning could significantly improve students' understanding of concepts, with N-gain = 0.56 and effect size = 2.38. This study explains the difficulties and general understanding of students on the concepts of distance and displacement, and the direction of object acceleration. In addition, the integration of assessment for learning to JITT is an option in the learning process to improve understanding of Kinematics concepts.
High impact on students’ understanding of atomics radius on crystals geometry concept through implementation of JITT with 3D animation Hena Dian Ayu; Akhmad Jufriadi; Ratri Andinisari
Momentum: Physics Education Journal Vol 5 No 2 (2021)
Publisher : Universitas PGRI Kanjuruhan Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21067/mpej.v5i2.5557

Abstract

This study was conducted to analyze the students 'initial and final understanding after the application of JITT with 3D animation, to identify students' responses and arguments, and to determine the impact of using JITT with 3D animation. This research involved 43 students of the 6th semester of the 2019-2020 academic year of the Physics Education study program of the Universitas PGRI Kanjuruhan Malang who took solid state physics course. Students' initial and final understanding was analyzed through responses and arguments presented during the pretest, while the impact of JITT application with 3D animation was analyzed based on the results of the pretest and posttest as well as student responses during the learning process expressed through short interviews and discussions. The qualitative and quantitative data generated from the mixed-method approach were analyzed simultaneously. The results show that the students understand that the atomic radius for all the different crystal lattices is the same, namely a/2. This was awakened by an early understanding of the general definition of the radius. However, after following the JITT stages with 3D animation, their understanding changed that the atomic radius of each crystal lattice is different in length. In addition, the results of statistical analysis showed that there was a very significant increase in the students' mastery of concepts from an average of 26.9 to 96.7. Meanwhile, the N-gain value is very high, namely 0.96 in the very effective category, which illustrates that JITT with 3D animation has had a high impact on students' understanding of atomic radius in the concept of crystal geometry.
Co-Authors Ahmad Nadhir Akhmad Jufriadi Akhmad Jufriadi Hena Dian Ayu Sukir Maryanto