Asian Transactions on Basic & Applied Sciences

Volume: 02, Issue: 06, January 2013
ISSN 2221-4291

Title: Effect of heating rate on thermo-stabilization prior to carbonization of soda rice straw lignin and its characterization
Author(s): Lucia Indrarti, Anung Syampurwadi, Yuyun Irmawati, Myrtha Karina, Yukie Saito
Paper ID: ATBAS-20209064
Pages: 1 - 5
Abstract: Carbonization of rice straw lignin has been conducted by thermal treatment at 1000oC under nitrogen atmosphere. Rice straw lignin was isolated from waste of pulp mill and purified by dilute acid chloride.The heating rate during thermo-stabilization was varied at 20, 40, 60, and 80oC h-1, respectively. Low heating rate of 20oC h-1 generates carbon content of 84.19% and crystallinity of 52%, higher than other heating rates as revealed from energy dispersive spectroscopy and X-ray diffraction. In addition, low heating rate shows fiber-like structure, closest to the structure of commercial sample. However, the heating rate had no effect on the development of graphitic structure.

Full Text: PDF (615 KB)

Title: Isolation of Prenylated Flavonoid from Ethyl Acetate Fraction of Artocarpus altilis Leaves using Counter-Current Chromatography
Author(s): Sofa Fajriah, Tjandrawati Mozef, Nina Artanti, Puspa D.N. Lotulung, and Jamilah Abbas
Paper ID: ATBAS-30216065
Pages: 6 - 9
Abstract: A counter-current chromatographic system (CCC) for isolation of prenylated flavonoid from Artocarpus altilis had been done. The two phase of solvent system composed of n-hexane- ethyl acetate-methanol-water (5:5:7:3, v/v/v/v) had been selected by HPLC. About 100 mg amount of ethyl acetate fraction of A. altilis was separated, yielding 5 mg of compound 1. The purity of compound 1 was 98%, determined by HPLC analysis. The chemical structure of compound 1 was identified by ESI-MS, 1H- and 13C-NMR as prenylated flavonoid group, [1-(2,4-dihydroxyphenyl)-3-[8-hydroxy-2-methyl-2-(4-methyl-3-pentenyl)-2H-1- benzopyran-5-yl]-1-propanone].

Full Text: PDF (244 KB)

Title: Simulation of Earth geomagnetic field at An-najaf governorate by using IGRF model
Author(s): Mohammad Jafar Al-bermani, Jamal Nasser Al-Obeidi and Amer Atyah Laftah
Paper ID: ATBAS-40221060
Pages: 10 - 18
Abstract: The 11th generation International Geomagnetic Reference Field (IGRF-11) model has been exploited to predict the geomagnetic elements for An-najaf governorate. The predicted values represent the mean for the year 2012 at different elevations above sea level for different points in the region. The predicted total intensity (F), horizontal intensity (H), declination (D), inclination (I), the north component(X),the east component(Y),and Down component(Z). Contour maps were drawn to these components(X,Y,Z,H,F,D,I), The magnetic anomaly also found in the area known as the Sea of Najaf and confined between latitudes (31° -- 31.9°) , and especially in the contour lines of (D,I,H,F).

Full Text: PDF (525 KB)