Concentrations of ammonia, methane, and nitrous oxide were measured as the environmental conditions in the cattle barns and units for pig and poultry, the main domestic livestock. The objectives were to establish a method to calculate the environmental load gases developing from these facilities, which are the production site for livestock, and at the same time to make an environmental estimate here, which is also the farmer’s workplace. In total, 26 livestock houses of measurements had made seasonally, distributed by species as nine dairy cattle, four beef cattle, eight pigs, and five poultry in 2000-2002. The average ammonia concentration in each cattle barn (1 ppm-1.5 ppm) and pig/layer units (0.9-2.9 ppm) showed a great difference and an obvious seasonal variation. The methane emission contribution of the cow accounted for a large part of the methane total. The average methane concentration was in the range of 6.0-26.8 ppm, and the level declined in summer. The majority of the nitrous oxide was an excrement origin. Average Nitrous oxide concentration ranged from 0.306 to 0.650 ppm, and the difference in levels between barns was comparatively small. A high nitrous oxide concentration was observed especially in the beef cattle barns.

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In odor control of fermentation gas (NH₃ : up to 3, 000 ppm) from livestock excrement, we have reported that the combustion method could be the effective system in the practical deodorization methods. However, the use of this method has not spread to the small-scale livestock-breeding farmhouses because a running cost was too high.
A new system for drawing a fermentation odor gas into the diesel engine and burning the odor gas was developed to settle the problem of cost. The deodorization of the gas exhausted from the compulsory fermentation device for livestock excrement was examined using this system. The decomposition of the main odorants was 100% and the deodorization efficiency was over 94% at the generation condition of electric power of 8.6 kW in the practical examination for 30 days. It was recognized that the running cost of the fuel could be offset by the generation of electricity, if the electric power was used effectively. Nitrogen oxide (NOx) concentration in the diesel engine exhaust gas was in the range from 1/10 to 1/3, compared with the emission standard of Air Pollution Control Law in Japan.
Therefore, it would be expected that the proposed system is useful for the odor control of the high concentration sources such as livestock-breeding fermentation facilities, food compost faciliies and painting factorys.

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During olfactory adaptation, the perceived odor intensity has long been thought to decline as an exponential function. It was recently reported, however, that cognitive factors might influence the perceived intensity of odors during experimental exposures. Using triethylamine as an odorant, we continuously measured subjects’ perceived odor intensity over 10 minutes. We classified the resulting perception curves to five typical patterns. In the most common pattern, perception varied in a fluctuating manner, and approximately 30% of all curves were classified as exponential.

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This experiment was aimed to investigate the effect of description about odor on perception of the odor. In this experiment, unfamiliar odor stimulus (anethol) was presented with a description about the odor to participants. Half of the participants received a positive description about odor, and the other half received a negative description about the odor. As a positive description, the experimenter sharpened a positive aspect of the odor description, such as used as spice and used in aromatherapy. On the other hand, as a negative description, the experimenter sharpened a negative aspect of the odor description, such as used as pesticide and had a harmful for organisms. Then participants smelled anethol for 20 minutes, and were asked to evaluate intensity for the odor using an apparatus which had real time recorder. There were no significant differences in averaged intensity ratings in every 5 minutes between the groups. However, there were differences among intensity curves which were made on real-time recordings of intensity ratings. Significant differences in hedonic ratings were found between the groups. Participants in the positive group rated the odor as more pleasant than those in the negative group.

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