Spontaneous emission from a three-level atom placed in three-dimensional photonic crystals in the long-time limit

The paper describes the spontaneous emission from a three-level atom placed in a periodic dielectric microstructure which exhibits a complete three-dimensional photonic band gap. By using the Euler approach, the upper level population of the atom is calculated for a wide range of relationships between the Rabi frequency and the detuning of the atomic transition frequency from the upper band edge. The results indicate that there are three cases of the relationship between Rabi frequency and detuning, which determine distinctive states of the atomic population in the long-time limit. When the detuning is greater than the Rabi frequency, the upper level has a zero steady-state atomic population, which leads to enhancement of spontaneous emission. When the magnitude of the detuning is less than the Rabi frequency, the upper level has a nonzero steady-state atomic population, which leads to suppression of spontaneous emission. When the negative detuning is greater than the Rabi frequency, the upper level has a nondecaying oscillatory-state atomic population due to long-time atomic splitting. These three properties of the spontaneous emission are relevant to several optical devices on an atomic scale, such as optical memories, switches and clocks.     

Isolation of methyl ferulate from rice bran oil

An unknown ferulate in rice bran oil was isolated by column chromatography. The ferulate was identified as methyl ferulate by TLC, GLC, UV, IR, NMR and mass spectrometry.     

On the structure of highly unsaturated fatty acids of fish oils by high resolution nuclear magnetic resonance spectral analysis

Methyl esters of highly unsaturated fatty acid concentrates were prepared from fish oils by the urea-adduct method. The nuclear magnetic resonance spectra of the mixed esters and some related pattern compounds were analyzed. As a result, it was concluded that the structure of highly unsaturated fatty acids has divinylmethane arrangement of the ethylenic bonds and no divinylethane arrangement, and that one methylene group is present between the terminal methyl group and the double bond located at the remotest position from a carboxyl group in the acids.     

Hemodialyzability of ionizable fluoride in hemodialysis session

The fluoride ion content in serum and in dialysate medium was determined by means of a fluoride ion-selective electrode in 29 patients undergoing hemodialysis treatment. Abnormally high serum fluoride of 65.9 +/- 28.3 microg l(-1) at the beginning and 46.5 +/- 26.7 microg l(-1) at the completion of the hemodialysis session was observed. Results showed that 60.0 +/- 23.9% of the serum fluoride at the beginning of the session was theoretically filterable, and 80.8 +/- 42.4% of this fraction was actually filtered throughout the hemodialysis session. The dialysis procedure is considered to be safe and adequate for serum fluoride removal. The high serum fluoride at the completion of the hemodialysis session was thought to originate from the fraction of unfilterable binding fluoride. To make further progress towards improvements in serum fluoride removal during HD, attention to the binding fraction of serum fluoride is required.