Trials on the transmission of olfactory information together with audio/visual information are currently being conducted in the field of multimedia. Movies show multiple objects simultaneously, and the emission of multiple scents synchronized with scenes is considered to enhance the sense of reality.
This study examines a presentation technique of scent designed for users to recognize multiple scents in a short time period. Here, pulse ejection was applied for short periods and the olfactory characteristics of scent were measured during the emission of two kinds of scent in a single breath cycle. The minimum interval time in which the subject could discriminate the two individually emitted pulses of scent was defined as the “separable detection threshold”, and the minimum interval time in which they could specify both scents as the “separable recognition threshold”. Further, when a scent was emitted in a pulse, “response time” and “continuous time” were measured.
As a result, a correlation was seen for “separable recognition threshold” and “continuous time”. When the “continuous time” was long, the “separable recognition threshold” was large, and the pulse ejection interval should be set accordingly in order that all users can perceive two kinds of scents in a single breath cycle. It is expected that this presentation technique of scent will better enhance the sense of reality.

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The method of treating residual stench that becomes a problem after the resident was evacuated in the rental apartment houses was examined by the experiment. Three kinds of botanical-oil mist, graft-polymerization polymer paint film and ozone treating were taken up as a treatment method. The screening test performed with odorous paper towel of a pet smell, the cigarette smell, and the aroma smell in bags or chambers, and the processes that are more effective than the others were applied to real houses. The effect of both the paint film and some oil mist processing was not seen in a real house though they were effective in the screening test. The ozone treatment of 10ppm for 14 hours decreased the stench from odor intensity 4 to 2 in the real house. The findings about the process for removing the residual stench were obtained through the study.

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The existence of pyrolysis compounds from hardener of sand in working environment air at a foundry was investigated by quantitative analysis. Also, the concentrations and dilution ratio required until single component threshold of 72 volatile organic compounds (VOCs), 7 aldehydes and 2 ketones were analyzed. Additionally, the changes in air quality via the casting process are discussed in this study. As a result, numerous components such as VOCs and/or pyrolysis compounds were detected. Especially, acetaldehydes and xylene were dominated in the air. They also highly contributed to the dilution ratio required until single component threshold of the air.

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Odors emitted from cooking odors removal filter with the combined manganese oxide and zeolite were investigated. Trimethylsilanol, Acetic acid, Butylacetate, 1-Butanol, and Nonane, Decane, Heptacosane, and Tetracosane were emitted from cooking odors removal filter in high humidity condition. We found an optimal rate of activated carbon mixture for the maximum acetaldehyde removal and the least odor emission to reduce the odors emitted. When the mixing rate of activated carbon and zeolite was 10%, the removal efficiency of acetaldehyde was the maximum and odor emission was the least.

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