The correlation analysis between odor sensor and air dilution olfactometry method with odor emission facilities was performed for the real-time evaluation of odor emitted from the 13 facilities. The total correlation was less significant for all facilities due to various emission characteristics of odor. The correlation for the individual facility, however, showed a higher correlation coefficient (R=0.7371~0.9897). Especially, the strong correlation (above 0.9) was observed for the industry type with the odor characteristics like tobacco, styrofoam, acetic acid, and burning smell. The repeated odor measurements using the odor sensor showed good reproducibility with the mean relative standard deviation of 5.06%. The odor sensor could be useful tools for identifying and evaluating odor with an olfactometry in field, if the use and proofreading of the odor sensor are improved by a standardized method.

The object of this study is to investigate the relationship between the air dilution sensory test and the threshold odor number (TON) method for evaluating the odor of domestic wastewater, plating plant wastewater, food plant wastewater and lake water. The dilution factor of raw wastewater evaluated by the air dilution sensory test was in the order of food plant > plating plant > domestic > lake, and that evaluated by the threshold odor number method was in the order of food plant > domestic > plating plant > lake. The same results were obtained when the raw wastewater and lake water were diluted 2 and 5 times with pure water. The relative geometric standard deviation determined from the threshold values of each panel on the air dilution sensory test was much larger than that calculated from results derived from the threshold odor number method. The relative geometric standard deviation obtained from samples with a low dilution factor was greater. There was a very good linear correlation (correlation coefficient = 0.968~1.000) between the air dilution sensory test and the threshold odor number method. But, the reduction in odor intensity (the slopes of regression curves) by dilution was dependent on the types of the odor-emission sources.

2011년에 전국 79개 악취검사기관을 대상으로 공기희석관능법에 대한 숙련도 시험을 실시하였다. 악취방지법의 부지 경계선과 악취 배출원의 배출허용기준을 모사한 2개의 합성복합악취를 숙련도 시험물질(proficiency testing materials, PTM)로 사용 하였다. 부지 경계선 시료는 7ppm의 톨루엔과 7ppm m-자일렌의 복합악취로 구성하였으며, 배출구 시 료는 10ppm DMS (dimethyl sulfide)와 10ppm DMDS (dimethyl disulfide)의 복합악취로 구성하였다. 숙련도 시험 결과는 기준값으로 평균과 중간값을 사용하고, 목표표준편차로 일반 표준편차, 로버스트 표준편차 및 변동계수를 사용하여 Z-점수를 평가하였다. 시험결 과의 변동계수는 PTMs의 냄새강도가 증가함에 따라 감소하였다. 복합악취에 대한 숙련 도 시험 결과는 악취희석배율보다 로그 스케일의 악취지수를 사용하여 평가하는 것이 적 절했다. 두 PTMs에 대한 참여기관의 Z-점수를 변동계수, 표준편차, 그리고 로버스트 표 준편차를 사용하여 평가할 때, 참여기관의 95%가 숙련도 기준을 만족하였다. 목표 표준 편차를 변동계수의 20%로 설정하였을 때 참여기관의 만족도 비율은 부지경계와 출구 PTM 시료에 대해 각각 90%와 95%로 양호하였다. 이러한 결과들로부터 부지경계와 출 구의 복합악취를 모사한 두 합성 PTMs 모두 복합악취의 숙련도 시험물질로 적합하였다.

In this study, odors in N industrial complex in Incheon city were measured by using air dilution olfactory method, odor sensor and instrumental analysis method. Three industry categories which are plating industry, equipment manufacturing industry and petrochemical manufacturing industry were classified and the correlation of data was evaluated based on the measurement result. The correlation coefficient between the air dilution olfactory method and the odor sensor device utilizing method in 69 points was 0.562. The correlation coefficients in the classified industry categories were observed 0.889 in the plating industry, 0.723 in the equipment manufacturing industry and 0.832 in the petrochemicals manufacturing industry. It shows that when the correlation coefficient is over 0.75, they have a strong correlation. In this result, we could identify the ease of availability of the correlation using industry classification.

Since 2011, proficiency test for the air dilution olfactory method started in Korea for the evaluation of the authorized odor inspection agencies’ analysis skill. For this purpose, sulfur compounds of PTMs (proficiency test materials) were made and investigated for the application to the proficiency test as a complex malodor sample. Time stability and homogeneity between samples were analysed for the PTM which was made with 10 ppm of DMS and 10 ppm of DMDS. As the results, the stability of sample concentration with GC analysis was shown around 6%RSD through the time of 6~48 hr. In addition, dilution number during the same test period appeared almost stable, less than 6%RSD in air dilution olfactory method. The reproducibility results of four laboratories showed very similar results except one lab which was caused by the elder panel characteristics.

Recently, a Multi-Walled Carbon Nano Tube(MWCNT) is widely used to increase mechanical strength of the cementitious composite material. In this study, a dilution of MWCNT aqueous solution(from wt 2.0%, 1.5% to wt 1.0%) is a main parameter. A compressive strength of diluted CNT cement mortar is maximum 4.7% larger than that of a pure CNT cement mortar. The result indicates that the diluted MWCNT aqueous solution of the MWCNT cement mortar makes very little differences of the compressive strength.

Oil-in-ethanol (O/E) 마이크로에멀젼을 물에 희석하여 얻은 O/W 나노에멀젼의 성질에 대하여 다른 희석 과정의 영향을 연구하였다. 물/에탄올/비이온성계면활성제/실리콘 오일 계를 모델 계로 선택하였다. 희석과정은 물(또는 마이크로에멀젼)을 마이크로에멀젼(또는 물)에 단계별로 첨가하는 방법으로 구성되었다. O/E 마이크로에멀젼을 물에 첨가하여 혼합하면 30 nm 정도의 입경을 가진 나노에멀젼을 얻을 수 있었다. 반면에 물을 O/E 마이크로에멀젼에 첨가하면 400 nm의 입경을 가진 에멀젼을 얻을 수 있다. 희석 방법이 얻어지는 에멀젼의 성질에 중요한 역할을 하였다.시간에 따른 나노에멀젼의 입자 변화는 관찰되지 않았으나 입자가 큰 에멀젼은 시간에 따라 입경이 증가하였으며 불안 정화 기작은 오스트왈드 라이퍼닝으로 추정되었다.

In this study, the Dilution Method is used to measure river discharge through the hydraulic model test. the dilution method is divided into Constant-Rate-Injection Method and Slug-Injection Method in the river discharge measurement techniques. When the dilution method is applied in the hydraulic model flume, it is analyzied that the estimated error of constant-rate-injection method is less than that of the slug-injection method, and the result shows that floodflow analysis is more efficient than lowflow analysis as compared observed discharge with calculated discharge. The result of statistical error analysis shows that the constant-rate-injection method is appropriate technique for the measurement of the river discharge. Therefore, the dilution method among the river discharge measurement techniques can be applied for the river basin which can`t be measured with current meter or unsteady-flow regime in the urban-small drainage or hydraulic structure equipment area and can be obtained more exact results than any other discharge measurement techniques.