Article Per Year (5 Year)
p-Index From 2018 - 2023
1.037
P-Index
This Author published in this journals
All Journal Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Omega: Jurnal Fisika dan Pendidikan Fisika Jurnal Pendidikan Fisika dan Keilmuan (JPFK) Indonesian Review of Physics (IRiP) Makara Journal of Science
wipsar sunu brams dwandaru
Yogyakarta State University,
Astronomy Earth & Planetary Sciences Education Materials Science & Nanotechnology Physics

Published : 7 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search
Journal : Makara Journal of Science

 1 
Morphological and Structural Studiesof ZnO Micro-Nanorod Structures Synthesized Using a Low-Cost Hydrothermal Method Alfarisa, Suhufa; Toruan, Parmin Lumban; Atina, Atina; Dwandaru, Wipsar Sunu Brams; Safitri, Rika Noor
Makara Journal of Science
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Micro-nanorod structuresof zincoxide (ZnO) have been successfully synthesized via a simple and low-cost hydrothermal method. ZnO solutions with different concentrations of 0.05 and 0.1 M were prepared using zinc nitrate tetrahydrate and hexamethylenetetramine precursors. They were dissolved inaquadesand stirred before the hydrothermal process at 95 °C for 4 hours in an oven. Extensive characterizations using scanning electron microscope (SEM) and X-ray diffraction (XRD) were conductedon ZnO powder samples. SEM results showed that hexagonally shaped ZnO micro-nanorods were formed with diameters ranging from hundreds of nanometers to several micrometers. The ZnO sample synthesized at 0.05 M was observedto have a better surface morphological structurethan the 0.1 M sample. In addition, XRD measurements confirmed that samples exhibited a hexagonal crystal structure of ZnO. Moreover, the calculated crystallite sizes of ZnO using the Debye-Scherrer equation using the full-width half maxima of the XRD peaks were 25.153 nm for the 0.05 M sample and 28.707 nm for the 0.1 M sample. The most prominent growth of ZnO had 101 plane orientation or nonpolara-plane followed by nonpolar 100 m-plane and 002 polar c-plane orientations.This studyoffersa simple andlow-costroute to producehigh-quality ZnO micro-nanorods for use in various electrical and optical devices.
Density Profiles, Energy, and Oscillation Strength of a Quantum Dot in Two Dimensions with a Harmonic Oscillator External Potential using an Orbital-free Energy Functional Based on Thomas–Fermi Theory Alfarisa, Suhufa; Dwandaru, Wipsar Sunu Brams; Darmawan, Denny
Makara Journal of Science
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

This research aims i) to determine the density profile and calculate the ground state energy of a quantum dot in two dimensions (2D) with a harmonic oscillator potential using orbital-free density functional theory, and ii) to understand the effect of the harmonic oscillator potential strength on the electron density profiles in the quantum dot. This study determines the total energy functional of the quantum dot that is a functional of the density that depends only on spatial variables. The total energy functional consists of three terms. The first term is the kinetic energy functional, which is the Thomas–Fermi approximation in this case. The second term is the external potential. The harmonic oscillator potential is used in this study. The last term is the electron–electron interactions described by the Coulomb interaction. The functional is formally solved to obtain the electron density as a function of spatial variables. This equation cannot be solved analytically, and thus a numerical method is used to determine the profile of the electron density. Using the electron density profiles, the ground state energy of the quantum dot in 2D can be calculated. The ground state energies obtained are 2.464, 22.26, 90.1957, 252.437, and 496.658 au for 2, 6, 12, 20, and 56 electrons, respectively. The highest electron density is localized close to the middle of the quantum dot. The density profiles decrease with the increasing distance, and the lowest density is at the edge of the quantum dot. Generally, increasing the harmonic oscillator potential strength reduces the density profiles around the center of the quantum dot.
UV-Visible Optical Absorbance of Graphene Oxide Synthesized from Zinc-Carbon Battery Waste via a Custom-Made Ultrasound Generator based on Liquid Sonication Exfoliation Method Wisnuwijaya, Rhyko Irawan; Purwanto, Agus; Dwandaru, Wipsar Sunu Brams
Makara Journal of Science
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The objectives of this study are i) to synthesize graphene oxide (GO) from the waste materials of zinc-carbon (ZnC) batteries via the liquid sonication exfoliation (LSE) method using tweeter piezoelectric probes as speakers, and ii) to study the optical absorbance of the GO produced using a UV-Vis spectrophotometer by varying the mass of the graphite materials obtained from ZnC battery waste. The graphite materials are obtained from the carbon rods of the ZnC batteries, which are ground into powder. The powder is then mixed with distilled water, with powder mass variations of 0.4, 0.6, 0.8, and 1.0 grams. The solutions obtained are sonicated with a frequency of 30 kHz for six hours using a custom-made ultrasound generator based on piezoelectric probes. The effect of graphite material mass variation is studied by observing the UV-Vis spectrophotometer data before and after sonication. The results of this study show absorbance peaks at wavelengths of 221 nm to 227.5 nm, and shouldering peaks at 260 nm to 270 nm, indicating the presence of GO materials for all graphite mass variations. The best GO performances based on the UV-Vis results are obtained in samples with 0.8 and 1.0 grams of graphite powder, which undergo a red shift from 223.5 nm to 227.5 nm, respectively. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) are conducted upon the sample of 1.0 grams of graphite powder before and after sonication treatment. The SEM results before sonication show graphite materials forming in large chunks, whereas after sonication smaller islands of GO materials consisting of thin, transparent flakes are observed. The EDX results reveal that the sample material after sonication consists of 88% carbon, 11% oxygen, and a remaining 1% of aluminum, silicon, sulphur, ferrum, and zinc
Co-Authors AGUS PURWANTO Alfarisa, Suhufa Anak Agung Gede Sugianthara Andriani, Nur Baeity Atina, Atina Denny Darmawan Elisabeth Pratidhina Fauzi, Fika Hastuti, Irnawati Widya IMAN SANTOSO Nurohman, Yosi Pratama, Buki Wahyu Pujianto Pujianto Rahmatullah Rahmatullah Safitri, Rika Noor Sari, Dyah Silviana Sari, Emi Kurnia Suhendar, Haris Surya Jatmika Toruan, Parmin Lumban Wisnuwijaya, Rhyko Irawan