Biomedical subjects

Xing-Zhong Yuan

Publications and source records attributed to Xing-Zhong Yuan.

3 recordsLinked to original sources

PubMed2006

[Kinetic of pH control in anaerobic digestion of organic fraction of municipal solid waste in a batch reactor].

Using a material and ionization balance analysis of anaerobic digestion process, a kinetic model of pH control in a batch anaerobic digestion of organic fraction of municipal solid waste was established on the basis of substrate decay and microbial growth kinetics, and a corresponding computer soft ware was created. The optimal pH in different anaerobic digestion can be predicted by this model. Consequently the maximal methane production can be obtained in anaerobic system by controlling the pH in optimal value. Comparative experiments were conducted to validate the model. The experiments demonstrated that the methane production of anaerobic system under optimal pH was steadier than the same condition under uncontrolled pH, and the cumulative methane production had an average increment about 20%.

Bacteria, Anaerobic↗

PubMed2005

A ratiometric fluorescence sensor with broad dynamic range based on two pH-sensitive fluorophores.

This paper describes a novel ratiometric fluorescence sensor for pH measurement. Two pH-sensitive fluorophores, N-allyl-4-(4'-methyl-piperazinyl)-1,8-naphthalimide (AMPN) and meso-5,10,15,20-tetra-(4-allyloxyphenyl)porphyrin (TAPP), which served as referencing indicators for each other, were co-polymerized with acrylamide, hydroxyethyl methacrylate and triethylene glycol dimethacrylate on the silanized glass surface. The proposed sensor is based on the pH-dependent fluorescence intensities of the two fluorophores in different pH ranges. The sensor covers a broad dynamic range of pH 1.5-9.0. It exhibits satisfactory analytical performance in terms of selectivity, reproducibility and stability. The successful fabrication of the proposed sensor provides an alternative concept to utilizing two or more fluorophores for the development of ratiometric sensors covering a broad range of pH.

1-Naphthylamine↗

PubMed2005

[Application of biosurfactant in composting of agricultural waste].

The biosurfactant of rhamonolipid (Rh) obtained from Pseudomonas aeruginosa was used in co-composting of rice straw and wheat bran, the efficiency of the promoter was studied under temperature control during the first stage of composting. Composting was done in an aerobic static bed of composting during which moisture content of mixture materials was controlled between 60% 70%, and the control of aeration adopted the timer by turns of 0.18m3/h for 20 minutes and pause for 40 minutes. Changes were studied including pH, organic matter, dissolved organic carbon (DOC), the biomass of microorganism, hemicellulase activity, carboxymethyl cellulose enzyme (CMCase) activity, hemi-cellulose and cellulose contents. The experimental results show that the degradation rate of organic matter is 13.4% higher than that of the control, and the average of DOC is improved by 2.2g/kg. The degradation contents of hemi-cellulose and cellulose are increased by 5.7%, 10.7% compared with the control. This indicate that the addition of Rh can improve microenvironment, strengthen polymers hydration, accelerate the co-composting process and improve the quality of composting production.

Biodegradation, Environmental↗