Article Per Year (5 Year)
p-Index From 2019 - 2024
0.444
P-Index
This Author published in this journals
All Journal Jambura Physics Journal Jurnal Teori dan Aplikasi Fisika
Lydia Rohmawati
State University Of Surabaya
Education Energy Materials Science & Nanotechnology Physics

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

 1 
Sintesis Magnesium Oksida (MgO) dari Dolomit Bangkalan dengan Metode Leaching Devi Saputri; Lydia Rohmawati
Jurnal Teori dan Aplikasi Fisika Vol 9, No 2 (2021): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v9i2.2808

Abstract

Magnesium oxide (MgO) is a ceramic material that has potential in the medical and industrial fields, where MgO can be obtained from natural dolomite which has a composition of 21.9% MgO and 54.3% CaCO3. However, MgO from dolomite has not been studied much so that this study was conducted with the aim of analyzing the effect of the holding time of calcination on the synthesized MgO phase. The MgO synthesis method uses the Leaching method, which is dissolving dolomite with HCl and stirring it at 75 ° C for 45 minutes. After that, it is filtered where the results of the filtrate are added with ammonia until the solution reaches pH 12 and a precipitate is formed. Furthermore, the precipitate was filtered and dried at 90 ° C for 6 hours, and calcined at a temperature of 800 ° C with a variation of the holding time of 4, 8, 12, 16, and 20 hours. The calcined powder was characterized by XRD and FTIR. The results showed that the optimum MgO periclase main phase was formed at a holding time of 8 hours at a calcination temperature of 800 ° C and had a nanocrystalline size of 20.12 nm. FTIR results show that the MgO synthesized with a holding time of 8 hours has functional groups Mg-O, Mg-O-Mg, C = O, alkene groups, and H-O-H in the wave number range of 4000 cm-1 - 500 cm-1.
PROTOTYPE DESIGN OF 4 PROBE METHOD BASED ON MICROCONTROLLER WITH MEMORY CARD STORAGE MODULE Imam Sya'roni; Nugrahani Primari Putri; Lydia Rohmawati
Jambura Physics Journal Vol 4, No 2 (2022): October 2022
Publisher : Universitas Negeri Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34312/jpj.v4i2.15840

Abstract

The goal of this study is to create a prototype that uses a microcontroller to determine the physical phenomenon worth of a fabric victimisation, method by four-point probe. The amendment in resistance of a material once an electrical current flow through it's wont to quantify electrical conductivity. The example took measurements and saved them as data.txt. Using IC 741 100X gain amplifier circuit, prototype amplifies the output voltage and current for convenient monitoring. The source flag value is used in prototype calibration; the tolerance value for the measurement uncertainty of voltage is 2.1 percent and tolerance value of uncertantanty of current is 2.1 percent, respectively, based on comparisons with the calibration output. For voltage readings, prototype's measurement accuracy is 97.89 percent, and for current assignments, it's 97.64 percent. The output values will be saved and analyzed before being graphed to determine the material's conductivity value. Pani, a substance with a composition of 0.25 M anilin + 0.5 M HCL, was used to test the electrical conductivity of prototype Four Point Probe. The experiments were carried out by varying the voltage from 1 to 5 until the value of material conductivity Pani was between 0.9 and 1,25 x 107 (m)-1. Range 73.47 percent linearity value.
Co-Authors Devi Saputri Imam Sya'roni Nugrahani Primari Putri