Raman spectroscopy was applied to different-impurities-doped 6H-SiC crystals. It had been found that the first-order Raman spectra of N-, Aland B-doped 6H-SiC were shifted to higher frequency when comparing with undoped samples. However, the first-order Raman spectra of V-doped sample was shifted to lower frequency, revealing that there existed low free carrier concentration, which might be ind...

The last decade has brought much technical and commercial advancement in the field of Raman spectroscopy. More than ten years ago, the analytical community was immersed in the “Raman Renaissance” caused by the development and subsequent commercialization of FTRaman spectroscopy. The coupling of interferometry with 1064 nm Nd:YAG excitation enabled new applications of Raman where previous attemp...

The purpose of this study is to develop a method of evaluating the enzymatic activity of trypsin in a solid-state based on Fourier transform infrared (FT-IR) spectra using chemoinformatics and two-dimensional (2-D) correlation spectroscopy. Crystalline trypsin powders are compressed at 0-4000 kg cm-2 by a compression/tension tester. The enzymatic activity of trypsin is assayed by the kinetic de...

Because of the structural complexity of biomass, quantitation of lignin in a variety of wood and plant cell walls is difficult. Consequently, to measure lignin in different plant species, a number of different methods exist. The methods can give different values for the same material samples and such differences result from the nature of the biomass. In the past, although there have been many a...

*sN-substituted bacteriochlorophyll a (BChl a) was extracted from the cells of Rhodobacter sphaeroides 2.4.1 grown in a medium containing 15N-ammonium sulfate and yeast concentrate. The T, Raman spectra of 14Nand “N-BChl a were obtained as the difference spectra of high-power minus low-power of one-color, pump-and-probe measurements using 420 nm, 5 ns pulses. A set of empirical assignments of t...

An FT-IR Spectrometer is an instrument which acquires broadband NIR to FIR spectra. Unlike a dispersive instrument, i.e. grating monochromator or spectrograph, an FT-IR Spectrometer collects all wavelengths simultaneously. This feature, called the Multiplex or Felgett Advantage, is discussed in detail on page 3. FT-IR Spectrometers are often simply called FT-IRs. But for the purists, an FT-IR (...

An optical trap has been combined with a Raman spectrometer to make high-resolution measurements of Raman spectra of optically-immobilized, single, live red (RBC) and white blood cells (WBC) under physiological conditions. Tightly-focused, near infrared wavelength light (1064 nm) is utilized for trapping of single cells and 785 nm light is used for Raman excitation at low levels of incident pow...

We studied temperature dependence of complex capacitance, impedance, and polarized Raman spectra of single crystal Cs2Nb4O11. First, we observed a sharp lambda-shaped peak at 165 degrees C in the complex capacitance, then found drastic changes in the Raman spectra in the same temperature range. Utilizing the pseudosymmetry search of structure space group, we attributed the observed anomalies to...

NIR-FT-Raman as well as ATR-IR and NIR spectroscopy in combination with efficient chemometric algorithms was applied for rapid determination of piperine in black and white ground pepper and green whole pepper berries as well as pepper oleoresins. Most of the well-resolved Raman signals detected in the spectra of pepper and the related oleoresins can be assigned to piperine, which is known to be...

OBJECTIVE This study evaluated the molecular and morphological changes on dentin elements after Er:YAG laser irradiation. BACKGROUND DATA Spectroscopy studies reporting the effects of Er:YAG laser irradiation as an alternative to acid etching are needed to better understand the laser's effects. METHODS The occlusal one-third of the crown of six human third molars was removed. The dentin sur...