ABSTRACT
The radiative characteristics of char and ash in the pulverized coal furnace at the wavelength of 560 nm are analyzed here. The particles' radiative coefficients are calculated in the exit of the burner and in the upper part of the furnace separately according to the Mie theory. It can be inferred that in the exit of the burner, char has a great effect on the particles' radiative coefficient, which accounts for a percentage of 90%. While in the upper of the furnace, ash dominates the particles' radiative coefficient. The scattering ratio of the ash is calculated to be 91.6 and the scattering ratio of the char is only 50%.
ABSTRACT
The two-dimensional concentration distribution was reconstructed by using algebraic iterative reconstruction algorithm. This paper mainly focused on the effects of multispectral H2O absorptions on condition that the laser beam was less and the temperature was known, i.e. the influence of temperature on spectral line-strength was not considered as to this concentration distribution. Based on ART algorithm, increased spectral lines and increased laser beam were compared under the same concentration model. Three H2O lines were selected to reconstruct two-dimensional distribution of non-uniform gas concentration, and these three transitions were selected within the external cavity diode laser turning range in the simulated system. The interested region was discretized to 10×10 grid points, and the temperature and concentration of the reconstruction model were not evenly distributed, so the unimodal distribution and bimodal distribution were used to describe the concentration distribution. The simulated system also calculated the effective utilization of laser beams and absorption lines. The results showed that the reconstruction quality quickly increased with increasing H2O absorption lines when the laser beams were very few, the increased absorption lines could get more spectral information related to the concentration. The increased laser beam is also effective to improve the accuracy of reconstruction results, but increasing the absorption lines can better reconstruct a two-dimensional concentration distribution. Improving the absorption lines can also effectively reduce the costs of the hardware and the complexity of the measurement system, which shows that the multispectral absorption lines are applicable to in-situ measurements.
ABSTRACT
Headspace solid-phase microextraction HS-SPME) technique was employed to extract the volatile compounds from Pollen Pini. The volatile components were isolated and identified successfully by gas chromatography-mass spectrometry (GC-MS). The volatiles were collected using several SPME parameters (including extraction time and temperature). The best response was obtained using a PA fiber by when the extraction temperature was 70 degrees C, extraction time was 30 minutes and desorption time was 10 time. Analysis was performed by GC-MS. Seventy components were identified by HS-SPME. The main components were fatty compounds. The results showed that the HS-SPME technique could be used to extract the volatile components from HS-SPME-GC-MS.
