Biomedical subjects

Jun-De Wang

Publications and source records attributed to Jun-De Wang.

7 recordsLinked to original sources

PubMed2006

[Calibration transfer used for the interpretation of RS-FTIR spectrum].

A technique of analysis for RS-FTIR (Remote Sensing Fourier Transform Infrared) spectrum was built based on the principle of calibration transfer. A system of four-component gas mixtures, whose FTIR spectra were overlapped seriously, was determined as the object in the present research. Its FTIR data from EPA and field measurement were used to set up calibration and prediction models, respectively. With OSC (orthogonal signal correction), the model built with data of EPA predicted values of field measurement. The RMSEP values of acetone, methanol, benzene and chloroform were 0.0085, 0.0180, 0.0640 and 0.0028, respectively, while without OSC correction the corresponding values were 0.0856, 0.0479, 1.0653 and 0.0142, respectively. With optimization, the Kennard-Stone method was used for subset selection, and the iteration in the process of OSC was carried out 3 times, yielding the best performance. The result indicates that this technique can overcome the limitation of background and calibration model, which restricts the application of RS-FTIR in air monitoring.

English Abstract↗

PubMed2005

[Adsorption behaviors of chitosan and the analysis of FTIR spectra].

This paper studied the adsorption behavior of lab-made chitosan for acid dyeing waste water and basic dyeing waste waters, based on the effects of adsorbing time, deacetylation degree of chitosan, and pH of waste water. The results showed that the adsorption of basic fuchsin and saffron by the chitosan almost reached equilibrium state in 20 min. The adsorption capacities of the chitosan for dyes was comparable with activated carbon. Moreover, its dosages were only 2/3 of the latter. The adsorption process for Acid Red presented a dynamics character of first order reaction. FTIR spectroscopy was used to analyze the adsorption mechanisms of chitosan for different kinds of dyes. It was found that a great deal of hydroxide radicals in the chitosan molecule participated in the adsorption of basic fuchsin and saffron.

Acetylation↗

PubMed2004

[Combustion temperature measurement of solid propellant by remote sensing FTIR].

The combustion temperature of solid propellant was measured in this paper. Emission spectra of the combustion flame were collected with remote sensing FTIR at the resolution of 4 cm(-1). The combustion temperatures with the burning time were calculated from the maximum spectral line intensity and the molecular rotation-vibration spectra of HF molecule, respectively. Combustion temperatures at each time were all 1 788.8 K from the maximum spectral line intensity method. For comparison, the temperatures calculated from the molecular rotation-vibration spectra were 1 859.7, 1 848. 3, 1 804.0 and 1 782.7 K, respectively. Results show that the two methods are all dependable in measuring combustion temperature of solid propellant. But the maximum spectral line intensity method is more convenient and rapid than the other when the combustion is relatively stable.

English Abstract↗

PubMed2004

[Using wavelet transform for information extraction from remote sensing FTIR spectra].

How to use wavelet transform technology to extract information from remote sensing FTIR spectra, which were weak or always interfered by others, was described in the present paper. The Mexican hat function was used as a wavelet function to continuously transform the signals of pure chloroform, pure acetone and their mixture. The results indicated that the small scales were the guarantee of the accuracy of corresponding position between maximum module of wavelet transform coefficients and break points of peaks. However, only one scale could not determine the position of break point because of the effect of noise in small scales. On the contrary, maximum module of wavelet transform coefficients was relatively stable in large scales when noise was smoothed. But smoothness always brought deviation of orientation. Therefore, multi-scales should be combined to observe the break points of signals when using wavelet transform technology. All in all, the break points of signals could be determined accurately and stably by the wavelet transform technology and useful information was extracted. The signals were smoothed and magnified at the same time. According to the analysis of maximum module of wavelet transform coefficients and their orientation in different scales, some spectra, such as mixed and non-strongly-overlapped remote sensing FTIR spectra, could be recognized magnificently.

English Abstract↗

PubMed2002

Monitoring leaking gases by OP-FTIR remote sensing.

Measurement of leaking gases using Open Path Fourier Transform Infrared (OP-FTIR) spectroscopy was carried out in this study to acquire Path Integrated Concentration (PIC) data. Three hazardous Volatile Organic Compounds (VOCs) namely methylene chloride, chloroform and acetone were analyzed. For the two-component leaking source, the PIC data were easily obtained through ordinary calculation and compared to those obtained from Artificial Neural Network (ANN). When the leaking source was composed of three VOCs whose characteristic peaks interfere with each other, it was necessary to do spectral correction for multicomponent analysis with ANN. The Absorbance-Wavenumber-Time 3D spectra of the leaking sources and concentration variations with the leaking time were plotted. The results showed that OP-FTIR is a good quantitative analytical method for indoor or field air pollution. Further more, the remote sensing OP-FTIR system could be utilized to continuously monitor many more toxic gases and work as an alert system for the real time monitoring of hazardous gases beyond normal working conditions of various kinds of areas, such as living or industrial areas.

Acetone↗

PubMed2002

Study of isothermal adsorption of albumin on acetate fiber filter rod with dye affinity ligand.

Cibacron Blue F3GA was immobilized onto an acetate fiber filter rod to produce potential affinity matrix. The adsorption isotherms of the prepared matrix for either bovine serum albumin or human serum albumin were investigated. It was experimentally shown that the affinity isothermal adsorption obeyed Freundlich adsorption model. By means of affinity chromatography of human plasma using the prepared matrix, purified human serum albumin was obtained.

Adsorption↗

PubMed2002

[Study of the separation factors of basic compounds in HPLC using a reversed-phase amino-type column].

The chromatographic behaviors of some basic probes and a neutral reference compound were investigated as functions of temperature, buffer cation strength and flow-rate using a novel reversed-phase amino-type column at both pH 3.0 and pH 7.0. The results showed that the retention of basic compounds declined steeply at first, but then slowly when temperature increased continually at pH 3.0 while decreased slowly in the whole range of temperature at pH 7.0. The column efficiency increased and the peak shape improved with increased temperature. The buffer cation strength has a strong effect on the retention of bases. The optimum flow-rate for the highest efficiency is generally lower for basic compounds than neutral compounds, and due to the steepness of the van Deemter curves obtained, high flow-rates appear to be particularly detrimental in the chromatography of basic compounds. All the results indicated that the retention mechanism, was more complex for the analysis of bases on amino-type columns than on traditional reversed-phase columns because of the existence of amino group in the alkyl group of amino-type columns.

English Abstract↗