본 연구에서는 현행 악취공정시험방법에 나타나있는 공기희석 관능법을 사용하여 물질농도와 희석배수와의 관계를 살펴보기 위해 프로피온산, 뷰틸산, 발레르산, i-발레르산 및 i-뷰틸알코올에 대한 물질농도와 희석배수를 측정하였다. 또한 상관관계식을 이용하여 지정악취물질의 농도 규제치의 적정성을 검토하였다. 1. 판정인에 의해 측정된 대상물질의 물질농도와 희석배수의 상관관계는 식 Log C = Af·Log D + 0.5에 의해 적절하게 나타났으며, 총 22종의 지정 악취물질별 상관관계식의 기울기 값의 범위는 0.9023~1.2012으로 이소발레르알데하이드가 가장 작고, 뷰틸알데하이드가 가장 큰 것으로 나타났다. 2. 물질별 관계식으로부터 산출된 희석배수 15와 20에 해당되는 물질농도와 최소감지농도와의 비를 구한 결과, 각 물질의 농도비가 희석배수 15 및 20과 유사한 수치를 나타내 물질별 관계식이 의미가 있는 것으로 추정되었다. 3. 물질별 관계식으로부터 산출된 희석배수 15와 20에 해당되는 물질농도와 현행 물질농도 기준치와 의 비교를 통하여 기준치의 적정 수준 여부를 검토 해본 결과, 프로피온산과 뷰틸산의 경우는 기준치가 상대적으로 낮게 설정된 것으로 판단되며, 발레르산, 이소발레르산과 뷰틸알코올의 경우 물질농도 기준치가 적정 수준인 것으로 추정된다. 본 연구결과는 현행 악취방지법의 부지경계선에서 복합악취 농도 규제기준에 대한 개선방안 및 지정악취 물질들의 물질농도와 악취강도, 희석배수간의 상관관계 및 특성연구 등의 기반 자료로 사용될 수 있을 것이다.

This study was aimed to evaluate the relationship between the concentration and dilution factor (ratio) using the Air Dilution Olfactory Method, which is suggested in the Standard Method of Odor Compounds, by measuring dilution factor for 5 types of aldehyde compounds and styrene. For the measurement, 13 panelists were selected by several criteria through panel test. Panelists chosen for their closely similar sensitivities provide more reproducible values. The estimation showed that the correlation of the concentration with dilution factor for the 12 compounds including the sulfur compounds, ammonia, and trimethylamine can be reasonably expressed by the equation log C=Af∙logD+F(Af: material constant, F: constant). The result of this study is suggested to be used as a base data for research on measures to improve the regulation standards for complex odor concentration on site boundary in operation, as well as a correlation between the concentration and dilution factor for the designated foul odor substances, and their characteristics.

This study aims to evaluate the relationship with the concentration and dilution factor using the Air Dilution Olfactory Method, which is suggested in the Standard Method of Odor Compounds, by measuring dilution factor for 4 types of sulfur compounds, ammonia, and trimethylamine. For the measurement, 13 panelists were selected by several criteria through a panel test. Panelists chosen for their closely similar sensitiviyies provide more reproducible values. The estimation showed that the correlation of the concentration with dilution factor for the 6 compounds can be reasonably expressed by the equation logC=AfㆍlogD+F (Af: material costant, F: constant). The result of this study is suggested to be used as a base data for research on measures to improve the regulation standards for complex odor concentration on site boundary in operation, as well as a correlation between the concentration and dilution factor for the designated foul odor substances, and their characteristics.

Critical nitrogen concentration (Nc), which is defined as the minimum % N in shoots required to maintain the maximum growth rate of top dry weight (W) at any time, was determined for rice plant. Using two rice varietal groups, japonica varieties and an indica ~times japonica "Dasanbyeo", 18 data points fulfilling the statistical criteria for determining Nc were obtained through eight N-fertilization experiments over two years at Suwon (37~circ 16'N), Korea. Nc dilution curve for each variety was obtained by fitting the Nc-W relationship to power function. However, The critical nitrogen curves for the two variety groups were not different statistically. Thus, a Nc dilution curve was fitted for the Nc data points pooled over the two variety groups and proposed in rice as: Nc=4.08, where W＜1.73 t h a-1 , Nc=5.197 W0.425 3/ (R2 =0.964), where 1.73 t h a-1 ＜W＜12 t h a-l . The Nc for W＜1.73 t h a-l were estimated as a constant value of 4.08%, the mean value of the maximum N concentration for N-limiting condition and the minimum N concentration for N non-limiting condition. The model for Nc is applicable to diagnosing the nitrogen nutrition status during the rice growth period from emergence to heading stage. The Nc curve well discriminated the 144 data points between the N limiting and the N non-limiting groups regardless of varieties, cultural methods, and years.-limiting groups regardless of varieties, cultural methods, and years.