Infrared diode laser spectroscopy of the deltanu=2 band of AlF

A vibrational-rotational spectrum of the deltanu=2 transitions of a high-temperature molecule AlF was observed between 1,490 and 1,586 cm(-1) with a diode laser spectrometer. Measurements were made on the nu=3-1, 4-2, 5-3 and 8-6 bands at a temperature of 900 degrees C. Measured spectral lines were fitted to effective band constants nu(0), B(nu) and D(nu) for each band. Present measurements were made with only one Pb-salt laser diode. Physical significance of the effective band constants is discussed.     

Infrared diode laser spectroscopy of the ν = 2 band of AlF

A vibrational–rotational spectrum of the ν = 2 transitions of a high-temperature molecule AlF was observed between 1490 and 1586 cm⁻¹ with a diode laser spectrometer. Measurements were made on the ν = 3–1, 4–2, 5–3 and 8–6 bands at a temperature of 900 °C. Measured spectral lines were fitted to effective band constants ν₀, B_ν and D_ν for each band. Present measurements were made with only one Pb-salt laser diode. Physical significance of the effective band constants is discussed.     

Studies on marine natural products. IV The stereochemistry of 13-membered carbocyclic cembranolide diterpenes from the soft coral lobophytum pauciflorum (Ehrenberg)

The relative and absolute stereochemistry of two 13-membered carbocyclic cembranolides was determined as shown in $\text{1}$ and $\text{2}$ on the basis of NMR spectral evidence.     

Cholesteric liquid crystals as weathering indicators for marble surfaces

Cholesteric liquid crystals have been used to study the weathered surfaces of marble from the Sanctuary of Demeter in Eleusis, near Athens. Previous investigations have shown that when a cholesteric phase is spread across the surface of the stone, the pitch of the mesophase is sensitive to the topography of the surface. The wavelength of the maximum in the reflected spectrum varies therefore with the microtexture of the surface. Small samples of surface stone from the temple which had been weathered in distinctive ways, were investigated in the laboratory. There appears to be a significant correlation between the optical reflectance spectra and the surface microtopography investigated by SEM, as indicated by computer aided analysis (Digital Image Processing). The results point to the development of an effective in situ method of monitoring the weathering of marble surfaces using cholesteric liquid crystals.     

Thermographic studies of plastered mosaics

In this work, different mosaics covered with various plasters (of thickness and composition) were evaluated in lab by means of various thermography approaches with the intention of detecting the tesserae beneath the plastered surface. Thermal images, as well as the thermal contrast curves between plain plastered surfaces and plastered mosaics were recorded. Results from the assessment are presented and discussed, indicating that images seeing through the mortar–plaster on plastered mosaic surfaces can be obtained using numerous thermography approaches.