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Rahmi, Rahmi
Chemical Department, Faculty of Mathematics and Natural Science Universitas Syiah Kuala, Jalan Teuku Nyak Arief, Darussalam Banda Aceh 23111
Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemistry Earth & Planetary Sciences Energy Engineering Immunology & microbiology Neuroscience Physics

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Viscosity Measurement of Blended Patchouli Oil at Atmospheric Pressure and Room Temperature Yusibani, Elin; Woodfield, Peter Lloyd; Ardiah, Lena; Surbakti, Muhammad Syukri; Rahmi, Rahmi
Journal of Engineering and Technological Sciences Vol 51, No 5 (2019)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (310.369 KB) | DOI: 10.5614/j.eng.technol.sci.2019.51.5.6

Abstract

Patchouli is an essential oil used in perfumes, cosmetics, soaps, insect repellents and also a candidate for biodiesel from non-edible oil. Patchouli oil from Aceh Province, Indonesia, is generally produced using a distillation process. The relationships between physical properties, i.e. the viscosity and quality, of patchouli oil from Aceh Province and blends with other oils, were investigated. The mixture oils used were palm oil, kerosene and lubricant oil SAE 40. The mixture compositions were 100:0; 75:25; 50:50; 25:75 and 0:100 (v/v). It was found that mixing palm crude oil (25%) or lubricant oil (25%) with patchouli oil increased the viscosity by about 41% and 72%, respectively, compared with pure patchouli oil. A 53% decrease in viscosity was observed when the patchouli oil blend contained 25% kerosene. Natural variation in patchouli alcohol (PA) and iron (Fe) content in the patchouli oil sample was found to increase the value of viscosity by up to 1.5%.
Isolation and characterization of cellulose from rice husk waste and sawdust with chemical method RIZKI ANDALIA; RAHMI RAHMI; JULINAWATI JULINAWATI; HIRA HELWATI
Jurnal Natural Volume 20 Number 1, February 2020
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (324.486 KB) | DOI: 10.24815/jn.v20i1.12016

Abstract

Cellulose had been isolated from rice husk waste and sawdust with chemical method through hydrolysis with HCl 2.5 N and bleaching process with  H2O23%.The yields were 13,45% and 22,75% (w/w) of cellulose from rice husk waste and sawdust, respectively. The chemical treatment caused partial removal of lignin and hemicellulose from raw material showed by FTIR spectrum.  Structure and morphology of cellulose from rice husk waste and sawdust were investigated using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The XRD patterns showed cellulose structure converted from amorphous to crystalline form after bleaching process while SEM images showed that the isolated cellulose from rice husk waste had rougher surface than cellulose from sawdust. The SEM micrograph also showed that the isolated cellulose from rice husk was in the form of aggregates.
Physical and Chemical Properties of Indonesian Coffee Beans for Different Postharvest Processing Methods Elin Yusibani; Peter Lloyd Woodfield; Adi Rahwanto; Muhammad Syukri Surbakti; Rajibussalim Rajibussalim; Rahmi Rahmi
Journal of Engineering and Technological Sciences Vol. 55 No. 1 (2023)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2023.55.1.1

Abstract

The purpose of this study was to identify the physical and chemical properties of Indonesian coffee beans for different postharvesting methods after being roasted. Several types of Indonesian export coffee, i.e., Gayo Luwak coffee, Wamena coffee, Toraja coffee, Gayo coffee, Flores coffee and Kintamani coffee, were used in the present study. Each coffee has its own aroma and taste according to the location, soil type, and land elevation. The roasting process started with preheating the roasting machine, after which the samples were roasted for about 15 minutes at 215℃ to obtain the medium-to-dark (MTD) roasting level. The physical properties measured included density, mass loss, porosity, water content, and morphology using a scanning electron microscope. The transmittance spectrum was observed by Fourier transform infrared spectroscopy (FTIR). The physical properties of the coffee were successfully measured. The bulk density varied from 0.6 to 0.7 g/cm3, and particle density was about 0.9 g/cm3 for green beans. The roasting process reduced the bulk and particle density to 0.3 g/cm3 on average and 0.8 g/cm3, respectively. The fully-washed condition gave an overlapping spectrum for green and roasted beans, which shows that the roasting process did not affect the spectrum. The results can be used to study the coffee quality resulting from different postharvest processing methods.
Co-Authors ., Julinawati Adi Rahwanto ANDALIA, RIZKI Ardiah, Lena Elin Yusibani HIRA HELWATI Marlina Marlina Nisfayati Juir Peter Lloyd Woodfield Rajibussalim Rajibussalim Surbakti, Muhammad Syukri Woodfield, Peter Lloyd