Articles

Found 9 Documents
Search

IRON CHELATING AND ANTIRADICAL ACTIVITY OF KAYU MANIK LEAVES (TREMA ORIENTALIS) Yudha S., Salprima; Angasa, Eka; Ningsih, Sri; Manaf, Syalfinaf; Murni, Suli Anggria; Umbara, Fatan
Indonesian Journal of Chemistry Vol 11, No 2 (2011)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (202.288 KB) | DOI: 10.22146/ijc.21410

Abstract

A methanol soluble fraction extracted from Kayu Manik leaves (Trema orientalis) from Seluma, Bengkulu, exhibited an antiradical activity 69.73% (scavenging activity of the stable 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical) that was almost similar to that of 1 mM ascorbic acid. On the other hand, the iron chelating activity was 40.74%. We believe that it would be useful to take the results as an alternative for processing industries and can be observed as a good source of new agent for iron chelator.
PELATIHAN PEMBUATAN DAN PENGOPERASIAN INSTALASI BIOGAS SISTEM KONTINU PADA KELOMPOK TANI KARYA BERSAMA, RT 15 KANDANG LIMUN KOTA BENGKULU Angasa, Eka; Ghufira, Ghufira; Asteria, Marisadonna
DHARMA RAFLESIA Vol 14, No 2 (2016): DESEMBER
Publisher : Universitas Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (587.205 KB) | DOI: 10.33369/dr.v14i2.4306

Abstract

Kegiatan pengabdian dilaksanakan dikarenakan sering terjadi kelangkaan gas sehingga harga gas menjadi tinggi. Kelangkaan dan tingginya harga gas menyebabkan masyarakat kembali beralih ke kayu untuk keperluan memasak sehari-hari. Sementara Kelonpok Tani Karya Bersama mempunyai potensi yang besar berupa limbah kotoran sapi yang dapat digunakan sebagai penghasil biogás. Biogas dapat dimanfaatkan untuk memasak sehari-hari. Pemanfaatan kotoran sapi menjadi biogás belum dilakukan karena tidak ada sumber daya manusia yang mampu mengolah kotoran sapi tersebut. Untuk itu, dilakukan pelatihan embuatan dan pengoperasian instalasi biogás sistem kontinu pada Kelompok Tani Karya Bersama, RT 15 Kandang Limun, Kota Bengkulu. Pelatihan dilaksanakan pada Kelompok Tani ini sebagai contoh bagi masyarakat lainnya. Kelompok tani ini telah berhasil membuat dan mengoperasikan instalasi biogas, sehingga ke depan diharapkan menjadi fasilitator munculnya instalasi-instalasi baru dan masyarakat peternak sapi tidak bergantung lagi pada gas dan minyak tanah. Keywords: Biogas, Instalasi biogás, digester  
COMPARISON THE PHYSICOCHEMICAL PROPERTIES OF BUNCH PRESS FIBRE CELLULOSE AND CYCLONE FIBRE CELLULOSE OF WASTE FROM INDUSTRY CRUDE PALM OIL (CPO) Gustian, Irfan; Angasa, Eka; Ghufira, G; Miliani, M; Hairulumah, H
International Journal of Science and Engineering Vol 6, No 1 (2014)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (336.896 KB) | DOI: 10.12777/ijse.6.1.47-51

Abstract

Study on comparison the physicochemical properties of bunch press fibre cellulose (Bpfc) and cyclone fibre cellulose (Cfc) wastes from industry Crude Palm oil (CPO) have been performed. The physicochemical properties both of celluloses have been done such as the average degree of polymerization (DP), solubility properties, functional group analysis, thermal properties and X-ray diffraction patterns. The average degrees of polymerization (DP) have been obtained 2195 and 567 for Bpfc and Cfc. Bunch press fibre cellulose and cyclone fibre cellulose were soluble in cupriethylenediamine (CED). FT-IR analysis showed the same pattern of spectrum but different intensities. Thermal stability of bunch press fibre cellulose and cyclone fibre cellulose remains stable up to a temperature of 250 °C. Glass transition bunch press fibre cellulose greater than the glass transition cyclone fibre cellulose and X-ray diffraction pattern shows the same pattern and intensity varies.
PREPARATION OF FE-INTERCALATED GRAPHITE BASED ON COAL TAILINGS, DIMENSIONAL STRUCTURE Gustian, Irfan; Angasa, Eka; Agustini, Dwi; Maryanti, Evi; Fitriani, Dyiah
Aceh International Journal of Science and Technology Vol 4, No 3 (2015): December 2015
Publisher : Graduate School of Syiah Kuala University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (669.343 KB) | DOI: 10.13170/aijst.4.3.3017

Abstract

Intercalated graphite from coal tailings have been modified through the intercalation of iron. Coal tailings which is a byproduct of the destruction process and flakes washing results from mining coal. Intercalation of iron goal is to improve the physical properties of graphite and modifying sizes of crystal lattice structure with thermal method. Modification process begins with the carbonization of coal tailings at 500ºC and activated with phosphoric acid. Activation process has done by pyrolysis at 700ºC. The results of pyrolysis was soaked in mineral oil for 24 hours, then pyrolysis again with variations in temperature 800°C and 900ºC for 1 hour and subsequent intercalation iron at 1% and 2%. Material before activated, after activated, and the results of pyrolysis still indicates order nano: 29, 25 and 36 nm respectively. X-ray diffraction characterization results indicate that change in the structure, the sizes crystal lattice structure of the material The greater the concentration of iron was added, the resulting peak at 2? = 33 and 35 also will be more sharply. The results of SEM showed different morphologies from each treatment.
ELECTROCHEMISTRY STUDY ON PVC-LICLO4 POLYMER ELECTROLYTE SUPPORTED BY BENGKULU NATURAL BENTONITE FOR LITHIUM BATTERY Ghufira, Ghufira; Yudha, Sal P; Angasa, Eka; Ariesta, Jhoni
Aceh International Journal of Science and Technology Vol 1, No 1: April 2012
Publisher : Graduate School of Syiah Kuala University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1621.461 KB) | DOI: 10.13170/aijst.1.1.13

Abstract

Abstract ? In this research bentonite was used as filler to produce polymer electrolyte (PVCLiClO4). Some weight variation of bentonite have been made by addition, such as 0% wt/wt; 5% wt/wt ; 10% wt/wt ; 15% wt/wt ; 20% wt/wt ; and 25% wt/wt of bentonite to the mixture of 0,5 gram of PVC and 0,125 gram of LiClO4. Ionic conductivity of polymer electrolyte was tested using impedance spectroscopy. The result of the research was showed that a mixture of PVCBentonite( 10% wt/wt)-LiClO4 gives the highest ionic conductivity (4,86 x 10-3 S.Cm-1). This result indicated that the presence of natural bentonite can be used as a filler in the current composite polymer electrolyte and can increase the ionic conductivity of the polymer electrolyte.
SINTESIS MATERIAL BESI BERPENDUKUNG ZnAl2O4 (Fe/ZnAl2O4) DAN KARAKTERISASINYA Angasa, Eka; Yudha, Sal Prima; Maryanti, Evi; Rahman, Taupik
Jurnal Riset Kimia Vol 4, No 2 (2011): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v4i2.125

Abstract

 ABSTRACT The aims of this work was to synthesize ZnAl2O4-supported iron material (Fe/ZnAl2O4). The Fe/ZnAl2O4 materials were prepared by impregnation of iron ions (FeCl3 and (NH4)2Fe(SO4)2 precursors) in solution to ZnAl2O4. Characterization of products using XRD shows that difractogram of Fe/ZnAl2O4 formed was similar to difractogram of Fe/ZnAl2O4 standard. This mean that ZnAl2O4-supported iron material has been successfully synthesized. Keywords: Iron, ZnAl2O4, impregnation
PHYSICO-CHEMICAL CHARACTERISTICS OF COMPOSITES MATERIAL BASED ON SULFONATED CYCLONE FIBRE CELLULOSE AND BENZOTRIAZOLE Gustian, Irfan; Angasa, Eka; Ghufira, Ghufira
Aceh International Journal of Science and Technology Vol 6, No 2 (2017): August 2017
Publisher : Graduate School of Syiah Kuala University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (526.393 KB) | DOI: 10.13170/aijst.6.2.8438

Abstract

Composites material based on sulfonated cyclone fibre cellulose (SCFC) and benzotriazole (Btri) have been prepared. Cyclone fibre cellulose (CFC) was sulfonated with trimethylsilyl chlorosulfonate (TMSCS), with high degree of sulfonation (150%). The composites material, SCFC-Btri were prepared by doping of benzotriazole in various mole ratios (0.125, 0.25 and 0.5). FTIR spectrum has confirmed the ionic interaction between sulfonic acid from sulfonated cyclone fibre cellulose and benzotriazole units. Thermogravimetric analysis (TGA) showed that the composites material was thermally stable up to 150 °C. The results showed that methanol permeability of the composite material was lower than pristine Nafion112. Activation energy obtained for the materials are 0. 106 eV, 0.144 eV and 0.137 eV for SCFC-Btri mole ratios 0.125, 0.25 and 0.5 respectively, composites material was expected to be used as raw material in the fuel cell.
Pengaruh Boraks, Asam dan Basa Terhadap Pergeseran Panjang Gelombang Ekstrak Air Bunga Rosella (Hibiscus sabdariffa Linn.) Oktiarni, Dwita; Khasanah, Siti Nur; Adfa, Morina; Nesbah, Nesbah; Angasa, Eka
GRADIEN : Jurnal Ilmiah MIPA Vol 12, No 2 (2016): (Juli 2016)
Publisher : Universitas Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (378.521 KB)

Abstract

Tujuan penelitian ini adalah untuk mengkaji pemanfaatan ekstrak air bunga rosella (Hibiscus sabdariffa Linn.) terhadap pergeseran panjang gelombang, yang ditambahkan dengan larutan boraks, asam (HCl), dan basa (NaOH) dengan menggunakan spektrofotometer UV-Vis. Adanya penambahan pereaksi boraks pada larutan bunga rosella mampu menggeser panjang gelombang dari 517 nm menjadi 558 nm. Penambahan pereaksi NaOH mampu menggeser dari 517 nm menjadi 583 nm. Sedangkan pada saat penambahan pereaksi HCl hampir tidak terjadi pergeseran panjang gelombang. Berdasarkan hasil analisis semikuantitatif dengan menggunakan spektrofotometer UV-Vis, larutan ekstrak air bunga rosella yang ditambahkan dengan larutan boraks pada konsentrasi 1%, memberikan puncak serapan pada panjang gelombang 558 nm, NaOH pada 583 nm, dan HCl pada 517 nm
Preparasi Polimer Elektrolit PVC/PEG – LiClO4 : Efek Surfaktan Dan Filler Hidroksiapatit Tulang Sapi Terhadap Konduktivitas Ionik Ghufira, Ghufira; Angasa, Eka; Fatimah, Shafaa Bhrenasj; Elviyanti, Sutra
GRADIEN : Jurnal Ilmiah MIPA Vol 12, No 2 (2016): (Juli 2016)
Publisher : Universitas Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (498.601 KB)

Abstract

Hidroksiapatit dari limbah tulang sapi telah berhasil di preparasi dan digunakan sebagai filler pada polimer elektrolit padat PVC/PEG-LiClO4. Jumlah hidroksiapatit divariasikan terhadap % berat total PVC/PEG-LiClO4 yaitu 2,5 %, 5,0 %, 7,5 %, 10,0 % dan 12,5 %. Nilai konduktivitas ionik tertinggi didapatkan dengan variasi hidroksiapatit 10 % sebesar  1,494 x 10-6 S/cm. Polimer elektrolit padat PVC/PEG-LiClO-HAP(10 %) digunakan untuk melihat pengaruh penambahan surfaktan deterjen dan surfaktan alami dari lidah buaya. Polimer elektrolit padat PVC/PEG-LiClO4-HAP(10 %) dengan penambahan surfaktan deterjen 0,04 g memberikan nilai konduktivitas ionik sebesar 3,56 x 10-5 S/cm. Sedangkan dengan penambahan surfaktan lidah buaya 0,10 g diperoleh nilai konduktivitas ionik sebesar 8,59 x 10-6 S/cm.