Garuda - Garba Rujukan Digital

Simple Investigation on the Optical Properties of Carbon Nanodots Using Lasers and a Lux Meter Febriani Febriani; Athi' Nur Auliati Rahmah; Bian Itsna Ashfa Al Ashfiya; Juli Astono; Wipsar Sunu Brams Dwandaru
Jurnal Fisika dan Aplikasinya Vol 18, No 1 (2022)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat, LPPM-ITS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j24604682.v18i1.11005

Carbon nanodots (Cdots) have excellent optical properties. This study aims to investigate scattering and absorption of Cdots via simple exposure of ultraviolet (UV)/violet, red, and green lasers. The experiment was conducted by preparing the Cdots from cajuput oil distillation wastes as the precursor. The solid wastes were dried under the sun, grounded into powder, filtered, and carbonized inside an oven at 250 oC for one hour. The carbonized powder was then mixed with distilled water, left for a night, and then filtered again so that the Cdots solution was obtained. Here, the mass of the precursor was varied. The Cdots samples were characterized using ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopies, and also particle size analyzer (PSA). The lasers were directly exposed to the Cdots samples. A digital lux-meter was used to measure the intensity of the lasers transmitted from the sample. The angle of the lux-meter was varied on a circular track. The sample was on the center of the track. The UV-Vis characterization showed two peaks at 217 nm and 270 nm, and a tail extending to the visible region. The PL characterization showed an intensity peak at 509.57 nm, which confirms the cyan luminescence of the Cdots. The PSA characterization indicated that the size of the Cdots was 1.04 nm. Moreover, at an angle of 0o, the UV wavelength was strongly absorbed by the Cdots in accordance with the UV-Vis characterization result. The intensity of the green laser also dominates as it was less absorbed and strongly scattered by the Cdots.

The Imaginary Line Across Yogyakarta Land as an Ethnomathemathics Study Febriani Febriani; Aditia Pramudia Sunandar; Ulfa Aulia Syamsuri; Wipsar Sunu Brams Dwandaru
Ethnomathematics Journal Vol 4, No 1 (2023): March
Publisher : Universitas negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/ej.v4i1.59984

In attempt to explore Yogyakarta, the heritage city of Indonesia, the well known landmark, Tugu Pal Putih and the Yogyakarta Imaginary Line is explored. The purpose of this paper is to describe that this cultural context may be used as a reference for geometry learning. The method used in this research is a descriptive qualitative involving two historian experts in interviews. The results are that this line can be explored through ethnomathematics studies based on points, straight lines, comparison of distances between points on the imaginary line and the extension of the imaginary line. This line can be illustrated by an imaginary point located at the Tugu Pal Putih as the starting point to focus on thinking of the mathematical object. This line not only divides Yogyakarta imaginatively but also according to natural boundaries such as rivers. The extension of the imaginary line forms an area called the fertility area. The description of the patterns formed on the Yogyakarta Imaginary Line through ethnomathematics is expected to be used further as materials in the mathematics learning process.

Pengembangan Instrumen Tes Fisika untuk Mengukur Kemampuan Representasi Verbal Siswa SMA pada Materi Alat Optik Pramudya Wahyu Pradana; Febriani Febriani; M. Ibnusaputra; Jumadi Jumadi
Jurnal Penelitian Pendidikan IPA Vol 9 No 10 (2023): October
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v9i10.3775

In the context of Physics learning, verbal representation is very important to foster problem solving skills. However, the role of these representations has not been thoroughly measured and supported by good measurement instruments. In addition, the topic of optical instruments has concepts that can be expressed with verbal representations and is one of the important topics in physics. Therefore, in this study, an instrument was developed to measure students' verbal representation ability on optical instrument topic. The objectives of this research are to (1) determine the instrument's construction and (2) find out the feasibility of the instrument. The instrument was developed following the modified Wilson, Oriondo, and Antonio procedure through three stages: design, testing, and test preparation. The test was piloted on 88 randomly selected students who had studied optical instrument topic. The analysis carried out in this development includes content validity, item-model fit, reliability, and item difficulty level analysis. The development was successful in providing feasible test instrument items for evaluating students' verbal representation of optical instrument topic. This instrument is expected to be used to capture information about students' verbal representation ability, which will then be analyzed to produce more appropriate physics learning instructions.

Pengembangan Instrumen Tes Fisika untuk Mengukur Kemampuan Representasi Verbal Siswa SMA pada Materi Alat Optik Pramudya Wahyu Pradana; Febriani Febriani; M. Ibnusaputra; Jumadi Jumadi
Jurnal Penelitian Pendidikan IPA Vol. 9 No. 10 (2023): October
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v9i10.3775

In the context of Physics learning, verbal representation is very important to foster problem solving skills. However, the role of these representations has not been thoroughly measured and supported by good measurement instruments. In addition, the topic of optical instruments has concepts that can be expressed with verbal representations and is one of the important topics in physics. Therefore, in this study, an instrument was developed to measure students' verbal representation ability on optical instrument topic. The objectives of this research are to (1) determine the instrument's construction and (2) find out the feasibility of the instrument. The instrument was developed following the modified Wilson, Oriondo, and Antonio procedure through three stages: design, testing, and test preparation. The test was piloted on 88 randomly selected students who had studied optical instrument topic. The analysis carried out in this development includes content validity, item-model fit, reliability, and item difficulty level analysis. The development was successful in providing feasible test instrument items for evaluating students' verbal representation of optical instrument topic. This instrument is expected to be used to capture information about students' verbal representation ability, which will then be analyzed to produce more appropriate physics learning instructions.

Title

Found 4 Documents
Search

Abstract

Abstract

Abstract

Abstract

Title Search

Found 4 Documents Search

Abstract

Abstract

Abstract

Abstract

Title

Found 4 Documents
Search