Narrow Results

High sensitivity sensing and in-situ monitoring of the ammonia concentration in feedlots could allow for quick acquisition of ammonia information and effective breeding. A laser monitoring system for ammonia was designed based on open-path Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology. The system has a millisecond time resolution, and the detection limit is about 5ppm-m. The ammonia concentration of a dairy feedlot in Changshu, Jiangsu Province was monitored in summer. Based on the results, ammonia concentration had a diurnal trend such that it was higher in the daytime than at night. The ammonia concentration increased during the activities of cow feeding and feedlot arranging. It peaked at a value of 5.3ppm at 9:00. In sum, optical technology for ammonia detection with high sensitivity, high time resolution without sampling was used and found to be an effective method for ammonia monitoring in dairy feedlots which provides technical support for scientific breeding.

Cellulose nanocrystals were extracted from cellulose raw material through hydrothermal process, and then polyaniline layer was coated on the surface of cellulose nanocrystals via in-situ chemical oxidative polymerization of aniline monomers. The resulting nanocomposite was investigated by scanning electron microscopy, Fourier transform infrared spectrometry, thermal gravimetric analysis, and gas sensing measurement. The results show the nanocomposite with good core-shell structure exhibited high thermal stability. For ammonia gas detection, high sensitivity, relative fast response, short recovery time, and good reproducibility can be achieved for the nanocomposite.