Article Per Year (5 Year)
p-Index From 2020 - 2025
0.562
P-Index
This Author published in this journals
All Journal Jurnal Ilmu Fisika Jurnal Polimesin
GUNAWATI, GUNAWATI
Unknown Affiliation
Astronomy Automotive Engineering Control & Systems Engineering Earth & Planetary Sciences Engineering Materials Science & Nanotechnology Mechanical Engineering Physics

Published : 3 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search

 1 
Physical and Chemical Properties of Gayo Coffee Brewed by Boiling Method with Variation of Particle Coffee Ground Yufita, Evi; Muhammad Shadiq Maula, Teuku; Gunawati, Gunawati; Lloyd Woodfield, Peter; Yusibani, Elin
Jurnal Ilmu Fisika Vol 17 No 1 (2025): March 2025
Publisher : Jurusan Fisika FMIPA Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.17.1.9-18.2025

Abstract

The effect of coffee ground particle size by the boiling method on the values of physical and chemical parameters is studied. The coffee used is Arabica (Luwak, wine, honey) and Robusta from the Gayo Highlands, Aceh Province, Indonesia. Extraction of the coffee brew uses the boiling method with different particle sizes of coffee grounds (fine and coarse). The caffeine content in the coffee brew is identified using the FieldSpec4 Hi-Res Spectrometer. The particle size of coffee grounds affected the coffee brew's physical properties and caffeine content. The physical properties in the form of the pH value of Arabica coffee brew are lower than Robusta in a range from 4.87 to 4.97 and 5.13 to 5.28, respectively. The pH of coffee brew with fine particle sizes is slightly higher than for coarse ones for Robusta coffee brew. The density of the brew is in the vicinity range of 0.99 g/cm3. Arabica and Robusta brews differ in viscosity and caffeine release, influenced by coffee particle size. Coarse particles yield more caffeine in Arabica, while fine particles release more in Robusta, demonstrating the impact of grind size on caffeine extraction in coffee.
Physical and Chemical Properties of Gayo Coffee Brewed by Boiling Method with Variation of Particle Coffee Ground Yufita, Evi; Muhammad Shadiq Maula, Teuku; Gunawati, Gunawati; Lloyd Woodfield, Peter; Yusibani, Elin
Jurnal Ilmu Fisika Vol 17 No 1 (2025): March 2025
Publisher : Jurusan Fisika FMIPA Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.17.1.9-18.2025

Abstract

The effect of coffee ground particle size by the boiling method on the values of physical and chemical parameters is studied. The coffee used is Arabica (Luwak, wine, honey) and Robusta from the Gayo Highlands, Aceh Province, Indonesia. Extraction of the coffee brew uses the boiling method with different particle sizes of coffee grounds (fine and coarse). The caffeine content in the coffee brew is identified using the FieldSpec4 Hi-Res Spectrometer. The particle size of coffee grounds affected the coffee brew's physical properties and caffeine content. The physical properties in the form of the pH value of Arabica coffee brew are lower than Robusta in a range from 4.87 to 4.97 and 5.13 to 5.28, respectively. The pH of coffee brew with fine particle sizes is slightly higher than for coarse ones for Robusta coffee brew. The density of the brew is in the vicinity range of 0.99 g/cm3. Arabica and Robusta brews differ in viscosity and caffeine release, influenced by coffee particle size. Coarse particles yield more caffeine in Arabica, while fine particles release more in Robusta, demonstrating the impact of grind size on caffeine extraction in coffee.
Physical and Thermal Properties of MgCl2 mixed with NaCl at Various Ratios for Solar Thermal Energy Storage Application Gunawati, Gunawati; Setiawan, Adi; Syahputri, Riana; Riskina, Shafira
Jurnal Polimesin Vol 23, No 2 (2025): April
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v23i2.6150

Abstract

Latent heat storage is a system capable of absorbing and releasing heat energy when a material undergoes a phase change. The material often used in this system is referred to as PCM (Phase Change Material). One of commonly used material for heat storage is salt. This type of material was chosen due to its low-cost and better in chemical-physical properties. This study aimed to find out the effect of combining NaCl with MgCl2 on the properties and performance of PCM. For preparation, MgCl2 was added to NaCl followed by manual mixing and grinding to ensure homogeneity. The samples were placed inside the muffle furnace and heated to 600°C. Next, the samples were evaluated for physical properties such as density, specific heat, and thermal conductivity, and tested for charging and discharging performance using a thermal box. The test results suggested that the higher MgCl2 content, the more specific heat capacity and thermal conductivity. However, it is inversely proportional to the density, where the lower the MgCl2 portion, the higher the density value. This caused the rate of thermal energy absorption and energy storage capacity increased significantly
Co-Authors Adi Setiawan Elin Yusibani Evi Yufita Lloyd Woodfield, Peter Muhammad Shadiq Maula, Teuku Riskina, Shafira Syahputri, Riana