Pre-filtering Effect in an Iterative Deconvolution Method and Its Application to Signal Recovery in Fiber-Optic Distributed Temperature Sensors

The signal quality of a fiber-optic distributed temperature sensor based on optical time domain reflectometry (OTDR) is improved using a pre-filtering technique in the iterative deconvolution method. Investigation of the performance is proposed using iteration conditions in which recovery rate of the signal-component is equal to that of the unfiltering technique. The recovered signal in the pre-filtering technique gives a good signal-to-noise ratio (SNR), 3 times of the unfiltered signal. Consequently, improvements in the OTDR signal with SNR of from 10 to 100 are obtained under the iterations for both distance and temperature resolutions.     

Quantitative determination of amorphous nicardipine hydrochloride in long acting formula (NIC-LA) using light anhydrous silicic acid

We investigated a method to quantitatively determine amorphous nicardipine hydrochloride (NIC) in the NIC-long acting formula (LA) model formulas prepared using NIC, light anhydrous silicic acid (LASA) and carboxymethylethylcellulose (CMEC). Consequently, since the quantity of total NIC in the formula can be determined by means of HPLC and crystal NIC can be determined by the differential scanning calorimetry (DSC) method because the heat of fusion (85.08 J/g) of NIC is constant and unaffected by excipients, we developed the HPLC-DSC method by which the quantity of amorphous NIC is calculated as the difference between the quantity of total NIC determined by HPLC and the quantity of crystal NIC determined by DSC. This practical HPLC-DSC method was confirmed to have good accuracy and reproducibility.     

Poly(thiaheterohelicene): a stiff conjugated helical polymer comprised of fused benzothiophene rings

A novel helical aromatic polymer comprised of fused benzothiophene rings, poly(thiaheterohelicene), was synthesized via an intramolecular ring-closing reaction with a controlled helicity to one-sided bias. The synthetic helicity control involved the induction of the helical conformation and its fixation. The ladder polymer showed both an extended pi-conjugation and planarity and a very stiff helical structure. [structure: see text]     

Topographic Analysis of Ocular Fundus Using the Fourier Transform Method for Projected Grating Images

In topography measurements of a local ocular fundus of the human eye using a grating-pattern projection technique, a pre-processing method to detect fringes accurately and a generalized Fourier transform method to analyze the fringe deformations are proposed. The method of analysis compensates for fringe deformations caused by instrumental characteristics. By combining the two methods, depth information can be determined with high accuracy. It is shown that the topographic parameters of the optic disc and the fundus slopes in the rim area are obtained with good reproducibility.