Deski Beri
Jurusan Kimia FMIPA, Universitas Negeri Padang, Padang, Indonesia

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Sintesis Keramik Refraktori Al2O3.MnO2.SiO2 Dengan Metoda Sol-Gel dan Sifat Fisikanya Dalam Berbagai Temperatur Kalsinasi Muthia, Rahmi; Beri, Deski; Amran, Ali
Periodic Vol 2, No 1 (2013)
Publisher : Jurusan Kimia FMIPA UNP

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Abstract

Ceramic oxide Al2O3.MnO2.SiO2 ceramics has relatively high strength, tough electrical capacitance and temperature resistant. It’s synthesized by sol-gel methods using raw materials Tetraethyl Orthosilicates (TEOS), Al (NO3) 3.9H2O and Mn (NO3) 2.4H2O with calcination temperature variation of 900-1100oC. XRD (X-Ray Diffraction) analysis of ceramic Al2O3.MnO2.SiO2 showes peak °2Th=33.2875 intensity relatif=100%, °2Th=55.8688 intensity relatif 24,28%,°2Th=26.1289 intensity relatif 13,22%,°2Th=66.4815 intensity relatif 12,84%,°2Th=35.4375 intensity relatif 11,39%. Ceramic Al2O3.MnO2.SiO2 morphology by SEM (Scanning ElectronMicroscopy) showed that the ceramic at a temperature of 1100oC was homogeneous microscopic. Capacity as measured by the LCR meter instrument empirical equation F (C, T) = 0.01625 T - 11.0833 can be explained that the higher the calcination temperature the higher the value of the capacitor capacity.
STUDI ab-initio MEKANISME PEMBENTUKAN TRANSISI REAKSI OKSIDASI CO OLEH NO2 DI UDARA Beri, Deski
Jurnal Sains dan Teknologi Vol 4, No 2 (2012)
Publisher : Jurnal Sains dan Teknologi

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Abstract

The transition state formation’s mechanism of CO oxidation reaction by molecule of NO2 has been done using ab-initio computation by Density Functional Theory (DFT). Geometry optimation was done by B3LYP and 6-31G* basis set using HyperGauss and HyperDFT computer software. The result is we hypothese that there was three transition state takes place, therewere trans-Transition State (KTt), cis-Transition State (KTc) and cyclic-Transition State (KTs). All of three was gradually takes place in a very short time intervals. Keywords: density functional theory (DFT), geometry optimation, intermediate, transition state