Papers by Yudhiakto Pramudya
Proceedings of the 2014 International Conference on Advances in Education Technology, 2014
Introductory Astronomy course for undergraduate physics education students is usually lack of han... more Introductory Astronomy course for undergraduate physics education students is usually lack of hands-on activities in the teaching process. In this paper, we discuss different strategies to get more interaction between the students and teacher. The active learning strategies were the review assignment, group presentation, battle game, and moon observation. The final project was writing popular articles about astronomy topics because the students should be ready to become science communicators as a part of physics teacher's duties. The technology role became important to share ideas, assignments and browsing the materials for the articles. The students gave positive responses in the motivation and understanding of particular topics. However, we will discuss some factors that have to be considered as potential problems to deliver active learning.
Journal of Physics: Conference Series, 2009
... sound in 4He Y Pramudya and FM Ellis Department of Physics, Wesleyan University, Middletown, ... more ... sound in 4He Y Pramudya and FM Ellis Department of Physics, Wesleyan University, Middletown, CT 06459 USA E-mail: [email protected] Abstract. ... We also work in one dimension with all variables appropriately film-averaged. ...
We have investigated alignment of self-assembled InAs quantum dot grown on an InGaAs buffer. The ... more We have investigated alignment of self-assembled InAs quantum dot grown on an InGaAs buffer. The density of the dots on the step-up is higher than on the step-down and the valleys of the height profile of the cross-hatch pattern. We deduce that the step-up position of the height profile is a preferential place for dot nucleation. Hence, the InAs QDs grown on an InGaAs buffer align on the cross-hatch pattern. We also characterized the dimension of the dots. The dot base length in the [011] direction is (180 ± 50) nm and the dot base length in the [011] direction is (80 ± 20) nm. We can conclude that the dots are elongated in the [011] direction. The dot height is (3.6 ± 1.9) nm. Surface chemical characterization of the InGaAs buffers was obtained by XPS using Mg K α (hν = 1253.6 eV) as light source. The Indium concentration at the surface within 4.2 nm depth is (16.3 ± 0.5)%. XRD measurements give the Indium concentration in the bulk to be 20 %. We can interprets this fact as an Indium desorption during annealing of the InGaAs buffer necessary for the growth of the InAs dots. This Indium desorption during annealing, which has not been reported in this context so far, needs to be considered when modeling InAs QD growth on InGaAs buffers. iv Acknowledgment The first of all, I would like to express my sincere thanks to my supervisors, Lucia Sorba and Stefan Heun (TASC, INFM) for their kind guidance and instructions throughout the period of the project. I also would like to express my sincere gratitude to ICTP, UNESCO, and IAEA for their kindness to give me opportunity to study at Diploma Course ICTP. Finally, I appreciate the cooperation of all of my colleagues at ICTP and TASC especially and helpful attitude toward me.
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Papers by Yudhiakto Pramudya