Steglich reaction between cholesterol and 6

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Unformatted text preview: d H-NMR spectroscopic techniques while the thermal behavior and texture observation of the mesogen was investigated by means of polarizing optical microscopy (POM). The experimental results indicate that this compound exhibits monotropic chiral smectic C (SmC*) phase upon super-cooling where broken-fan textures are observed under the polarized light. 142 3rd ICYC 2010 Universiti Sains Malaysia 23rd-25th June 2010 ORAL PRESENTATION (MATERIAL) MAT-O1 DIELECTRIC PROPERTIES OF NIOBIUM SUBSTITUTED BISMUTH TANTALATE A. Manshor and *K.B. Tan Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia E-mail: tankb@science.upm.edu.my A series of bismuth tantalate electroceramics, Bi3Ta1-xNbxO7 with different doped amounts of niobium ranging from 0.2 to 1.0 was synthesized by conventional solid -state method. The phase pure samples o were pelletized and densified at 900 C. A fluorite δ-Bi2O3 type phase was obtained and solid solutions limit ended at 0.6, i.e. 60 mol % of doped niobium. All doped samples showed good reproducible Arrhenius conductivity plots for heat-cool cycles. These samples were resistive with activation energy in the range of 0.9 - 1.1 eV. The dielectric properties study revealed an increase in permittivity values as x increase from 0.2 to 0.6. On the other hand, the temperature coefficient of capacitances (TCC) of all o doped samples were found nearly zero in temperature range 25 – 300 C. This interesting electrical properties making niobium substituted bismuth tantalates a promising candidate in dielectric applications. MAT-O2 THE POTENTIAL OF UNCARIA GAMBIR AND CATECHIN HYDRATE AS GREEN CORROSION INHIBITOR: A COMPARITIVE STUDY M. Hazwan Hussin and *M. Jain Kassim Material Chemistry and Corrosion Laborato ry, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia E-mail: mjain@usm.my Uncaria gambir, a native Southeast Asia herbal plant has been widely used as an astringent medicine for treatment of spongy gums, tooth acne, diarrheas and sore throat. Previous studies hav...
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