Al~tnu:t. Raman and infrared spectra of starch samples from sweet potato and different varieties of cassava (tapioca) are reported. Three regions of the spectra, the OH stretching region (3560-3000 cra-~), the CH stretching region (3000-2800 cm-t) and the finger print region (1600-200cm-1), have been studied. The results are discussed in relation to the hydrogen bonding and the properties of starch samples.

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Zinc borosilicate glass (ZBS) with the formula 60ZnO–30B2O3–10SiO2 was prepared by melt‐quenching method and the effect of addition of 0–15 wt% of α‐alumina (Al2O3) on the spectroscopic, dielectric, and optical properties of ZBS has been studied. Structural and microstructural modifications of ZBS with alumina addition were studied using X‐ray diffraction, spectroscopic (Raman and IR) and scanning electron microscopic techniques. The effect of Al2O3 on the photoluminescence properties of ZBS was also investigated.

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Raman and infrared spectra of NH,HZ(I0,), and KH,(I03), were recorded and analysed. The observed splitting!? of the stretching modes of 10, -are due to the distortion of the 10, octahedra. In NH,H,(IO,), , the ammonium ion can rotate freely and the NH,' group forms only weak hydrogen bonds with the oxygen atom. Owing to Fermi resonance, three stretching bands are observed for the OH vibration in both compounds. The hydrogen bonds are slightly shorter in KH,(I03), than in NH,H,(IO,), .