Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Terahertz Time-Domain Spectroscopy and Low-Frequency Raman Scattering of Crystalline and Glassy Pharmaceutical Indapamide

Kobayashi Y., Shibata T., Mori T., Kojima S.

International Letters of Chemistry, Physics and Astronomy

2015

Vol. 46

16--22

We performed terahertz time-domain spectroscopy and low-frequency Raman scattering on crystalline and glassy states of pharmaceutical indapamide (IND). We have determined the real and imaginary part of the complex dielectric constants and the imaginary part of the Raman susceptibility in the THz region. Several phonon peaks have been observed in the crystalline IND and the mutual exclusion principle of infrared and Raman spectroscopy holds in the measured frequency range. In a glassy state of IND, a broad absorption peak has been observed in both the THz and the Raman spectra with different spectral shape, and this disagreement indicates that the far-infrared and Raman lightvibration coupling constants are different in the glassy IND. A clear boson peak has been observed in the Raman spectra of the glassy IND at about 0.5 THz.

Thermoluminescence age of quartz xenocrysts in basaltic lava from oninomi monogenetic volcano, northern Kyushu, Japan

Shitaoka Y., Miyoshi M., Yamamoto J., Shibata T., Nagatomo T., Takemura K.

Geochronometria

2014

Vol. 41, no. 1

30--35

We determined the eruption age of basaltic rocks by application of thermoluminescence (TL) method, which is often used for TL dating, to quartz. Mafic magma only rarely includes quartz because of their mutual disequilibration. The basaltic lavas reported herein include quartz as xeno-crysts, as corroborated by their rounded or anhedral shape.The basaltic lava used for this study is from the Oninomi monogenetic volcano in northern Kyushu, Japan. The volcano eruption was estimated as occurring 7.3–29 ka because the lava exists between two widespread tephras: Aira-Tanzawa ash (26–29 ka) and Kikai-Akahoya ash (7.3 ka). We succeed-ed in collecting ca. 200 mg of quartz by decomposition of 30 kg of the lava samples. TL measure-ments for the lava indicate the eruption age as 15.8 ± 2.5 ka, which is fairly consistent with the strati-graphical estimation. Although the TL method has played a considerable part in constraining the timescale of Quaternary events, its application has been limited to silicic samples. The present result demonstrates the availability of quartz for dating even of mafic rock.