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Title: An automated method of ammonia flux measurement for agriculture
Author: Flint, Thomas Anthony
ISNI:       0000 0001 3470 7707
Awarding Body: University of Manchester Institute of Science and Technology
Current Institution: University of Manchester
Date of Award: 2002
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Ammonia emissions arising from intensive methods in agriculture are now recognized as having a considerable impact upon the wider environment. In addition to environmental pollution risks, concerns have been raised over livestock housing conditions with regard to the impact upon the health of employees and animal welfare. The goal was to develop a means of measuring ammonia flux emissions at the periphery of naturally ventilated livestock buildings in near real-time, as the basis for an automated system. Conducting polymer gas-sensors were determined to be the best approach to the problems of low-cost multi-point sampling in a relatively harsh environment. Sampling frequencies dictated an indirect measurement approach, requiring knowledge of wind velocity and ammonia concentration. Initial evaluation of polypyrrole-based sensor arrays located upon AromaScan™ A32S ceramic substrates, in conjunction with a commercially available Honeywell™ AWM3300 airflow sensor, indicated that ammonia concentration could be correlated to the pre-equilibrium rising response curves of a number of sensors. Simulation of a ventilation opening subjected to the vagaries of the UK weather, was undertaken at SRI and this work demonstrated that the gas-sensing arrays were integrating ammonia flux over time. Results for the new method of flux determination were compared with the "gold standard" values calculated from mass-loss values over time for the liquefied gas. Without the benefit of temperature and humidity compensation, there was a good correlation between the two methods although it became apparent that an exposure history compensation algorithm would be needed to adjust for extreme transitions in ammonia flux values.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available