The contents of this paper is to develop a passive sampler for H2S measurement. When the H2S gas exists in the air, AgNO3 solution coated filter of white used phenomenon which is exchanged with black. If the H2S gas concentration increased, the color of AgNO3 solution coated filter is discolored more black. H2S passive sampler measures the H2S gas concentration by changed color of AgNO3 solution coated filter. The reproducibility of the H2S passive sampler is very stable to within an error 5%RSD. The black color of AgNO3 solution coated filter showed a linear relationship with the H2S gas concentrations. In addition, correlation of the developed CDM and CR-10(Minolta, Japan) showed a high correlation to 0.99. Manufactured H2S passive sampler must be kept refrigerated, stability and reactivity was observed for up to 20 days

The milling characteristics of rice using different milling methods (dry and wet) were investigated. Generally, average particle sizes of dry-milling flours were bigger than those of wet-milling flours due to low moisture content. Three theoretical models for milling, such as the Rittinger, Kick, and Bond model, were applied to characterize the milling process of rice. The wet-milling method showed higher value milling constants including Bond’s work index. Baeksulgi was used to study the effect of the milling method and particle size on rice flour’s physicochemical property (water content, color value, and texture). Moisture content and hardness of Baeksulgi were smaller as the particle size became smaller. L value of Baeksulgi was greater as the particle size became smaller. The energy requirement for the milling of grains to obtain a suitable size of particles was estimated by the grinding models. The results of our study might provide a systematic way to estimate the energy requirement to obtain a suitable particle size by milling

본 연구에서 Tokyo-MOU의 정보시스템 APCIS와 해양수산부 항만국통제 정보관리시스템의 PSC 실태를 분석한 결과, 2009년을 기준으로 결함지적률(DFR)과 출항정지율(DTR) 모두 감소 추세를 보였다. 그러나 선령 30년 이상 선박과 편의치적 선박, Ro-Ro 여객선과 일반화물선, 총톤수 1,000톤 이하의 소형선박은 높은 DFR과 DTR을 보였다. 항만별로는 제주항을 제외한 전체 항만의 평균 DFR은 82.5 %, 평균 DTR 5.1 %로 나타났으며, 항만별로 큰 편차를 보였다. 각 항만별 PSCO가 점검해야 할 선박의 척수도 심한 지역 불균형을 보였다. 항만국통제관(PSCO)이 지적하는 우리나라 항만국통제의 가장 큰 문제점으로는 인력부족과 1인에 의한 단독점검으로 밝혀졌다. 우리나라의 PSC 점검 내실과 강화를 위해서는 고위험선박을 대상으로 한 집중점검, 4개 구역으로 한 권역별 인적 네트워크(협력체) 구축, 항만별 점검 할당량 재산정, PSCO 인력확보 등의 개선책이 필요하다.

This research determined the threshold value of 10 specified offensive odor substances based on the 3 point comparison sensory method. The panelist's thresholds were calculated by taking the arithmetic, geometric mean, and 50th percentile. Three methods of calculating the odor thresholds from the same data are compared. For 10 odor substances, the panelist's thresholds revealed a logarithmically normal distribution. The 50th percentile was the best method among the three methods of calculating the odor threshold from the 270 thresholds of 18 panels. As a result, the threshold values of individual odor substances, including i-valeric acid, n-valeric acid, n-butyric acid, and butyl acetate ranged between 0.0001~0.006 ppm, while the values of methyl ethyl ketone and toluene were relatively higher than that of other substances at 0.7107 ppm and 1.2139 ppm, respectively. The threshold values of the 10 specified odor substances were compared in Korea and overseas, which showed that the characteristics of sensory response varied by substance and nation.

The aim of this study is to analyze error cases induced during the proficiency test of certified odor measurement agencies. In the case of the homogeneity test performed in three panel groups, the geometric mean dilution factor of the site boundary PTMs(proficiency testing materials) was 1.4 ± 0.2, 1.7 ± 0.2, 1.8 ± 0.1 and that of the outlet PTMs was 3.7 ± 0.2, 3.7 ± 0.3, 3.7 ± 0.3, respectively. In the case of the stability test for 72 h, the geometric mean dilution factor of the site boundary PTMs was 1.6 ± 0.1 and that of the outlet PTMs was 3.6 ± 0.1. Among error cases induced during the proficiency test of certified odor measurement agencies, the proportion of error cases was in the order of case II(discontinuance of estimation)(40.0%) > case I(error on estimation procedure by panelist)(33.3%) > case III(miswriting of estimation result)(13.3%) > case IV(miswriting of dilution factor) and V(writing of wrong estimation result)(6.7%). Therefore, it seems likely that additional education related to error cases II and I is required.

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.

This study was carried out to investigate the response characteristics of a hydrogen sulfide electrochemical gassensor for several wastewater odors. At first, it was found that bubbling sampling method was superior toheadspace sampling method in terms of sensor sensitivity. High correlation between odor concentration and sensorresults was shown for two wastewater which were r=0.977 for food-waste recycling wastewater and r=0.997for food industry wastewater. On the other hand, no correlation (r=0.258) was found for plating wastewater,because hydrogen sulfide was not the main odorant for that.

Metallic Cr film coatings of 1.2μm thickness were prepared by DC magnetron sputter deposition method on c-plane sapphire substrates. The thin Cr films were ammoniated during horizontal furnace thermal annealing for 10-240 min in NH3 gas flow conditions between 400 and 900˚C. After annealing, changes in the crystal phase and chemical constituents of the films were characterized using X-ray diffraction (XRD) and energy dispersive X-ray photoelectron spectroscopy (XPS) surface analysis. Nitridation of the metallic Cr films begins at 500˚C and with further increases in annealing temperature not only chromium nitrides (Cr2N and CrN) but also chromium oxide (Cr2O3) was detected. The oxygen in the films originated from contamination during the film formation. With further increase of temperature above 800˚C, the nitrogen species were sufficiently supplied to the film's surface and transformed to the single-phase of CrN. However, the CrN phase was only available in a very small process window owing to the oxygen contamination during the sputter deposition. From the XPS analysis, the atomic concentration of oxygen in the as-deposited film was about 40 at% and decreased to the value of 15 at% with increase in annealing temperature up to 900˚C, while the nitrogen concentration was increased to 42 at%.

This research is carried out to investigate the odor emission characteristics in a sewage treatment plant. The plantwas divided into four areas (boundary areas, sewage treatment processes, sludge treatment processes and odortreatment plants), and measured around 27 sampling points. Odor characteristics from each areas were evaluatedby air dilution olfactory method and NH₃/SO₂/VOCs passive sampler, mainly in terms of spatial distribution. Themain odor emission sources were found out to be dewatering plant (S-4) of sludge, sludge transshipment place(S-5), and the outlet of odor treatment plant (B-2, B-3). The correlation between dilution number (OU) and ammoniaconcentration of passive sampler appeared to be low; correlation coefficient 0.49, but correlation coefficient for theresults of sulfur dioxide and toluene were very high, 0.95 and 0.93, respectively. These results indicate that odorcompounds form sewage treatment facility are mainly due to sulfur compounds and volatile organic compounds.

This study evaluated the concentration(OU/m3) of a complex odor being discharged from tire, feedstuff, bakery, paper, casting and painting manufacturing process, correlation between odor concentration(OU/m3) and the odor sensor was investigated. 4 type(A, B, C, D) gas sensors of metal oxide compounds are used in this study. Each odor sample of manufacturing process is diluted with odorless air and diluted odor samples were prepared for five different concentrations. Correlation results(R) of odor sample of tire, feedstuff, bakery, paper manufacturing process ware 0.86~0.99, and odor sample of casting, painting manufacturing process ware more than 0.93. Thus the odor concentration(OU/m3) evaluation by odor sensor was to determine the possible. In particular odor sensor B and D are likely to be effective for evaluation of odor concentration. However, odor samples before evaluation is needed the calibration process depending on the field odor sample to field apply.

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.

본 연구에서는 악취숙련도 시험을 위한 PTM 물질로 현장시료의 적용가능성을 평가하기 위하여 하수처리장에 채취한 현장시료의 안정성과 채취 균질성을 조사하였다. 또한 현장시료를 PTM으로 사용하여 71개 악취검사기관의 공기희석관능법의 숙련도 시험을 실시하였다. 다양한 설정값(참여기관 또는 기준기관의 악취지수 평균값이나 중위수)를 기준으로 3가지 Z-score 평가법(표준편차 이용한 Z-score, Robust 표준편차를 이용한 Z-score, 목표표준편차를 이용한 Z-score)으로 숙련도의 통계적 분석을 하였다. 하수처리장 농축조에서 채취한 현장시료는 2일 동안 희석배수의 변화 없이 안정적이었고, 참여기관을 4 그룹으로 나누어 순차적으로 채취한 현장시료가 균질한 것으로 평가되었다. 이는 현장악취시료가 악취 숙련도 평가를 위한 PTM 물질로 적용 가능함을 의미한다. 숙련도 시험결과의 통계적 분석을 통해 참여기관의 숙련도 만족비율은 Z-score 평가법이나 설정값의 기준(참여기관 또는 참고기관으로 선택한 3개 대학의 악취지수 평균값이나 중위수) 보다는 목표표준편차(S*ref)값에 의존하였다. 숙련도 만족비율은 S*ref 값이 증가함에 따라 증가하였으며, PTM 시료의 분석결과에 대한 변동계수(CV) 0.13에 해당하는 목표표준편차값에서 숙련도 만족비율은 약 93∼96% 수준이었다.

This study was carried out to provide the stable and homogeneous sample for the proficiency test which was applied for the olfactory dilution method of the offensive odor. For this purpose, the relationship between VOCs concentration and air dilution test results were analysed. As the results, the mixture of 7.1 ppm of toluene and m-xylene were suitable as a low level of PTM(proficiency test material) for air dilution olfactory method. In addition, time stability and homogeneity between samples were investigated through the time of 6 hr ~ 48 hr. As the results, the stability of sample concentration with GC analysis was shown as 5.1% RSD for toluene and 6.8 %RSD for xylene, respectively. The stability of sample was 5.4 %RSD in terms of air dilution olfactory method.

The ZnO thin films were grown on GaN template substrates by RF magnetron sputtering at different RF powers and n-ZnO/p-GaN heterojunction LEDs were fabricated to investigate the effect of the RF power on the characteristics of the n-ZnO/p-GaN LEDs. For the growth of the ZnO thin films, the substrate temperature was kept constant at 200˚C and the RF power was varied within the range of 200 to 500W at different growth times to deposit films of 100 nm thick. The electrical, optical and structural properties of ZnO thin films were investigated by ellipsometry, X-ray diffraction (XRD), atomic force microscopy (AFM), photoluminescence (PL) and by assessing the Hall effect. The characteristics of the n-ZnO/p-GaN LEDs were evaluated by current-voltage (I-V) and electroluminescence (EL) measurements. ZnO thin films were grown with a preferred c-axis orientation along the (0002) plane. The XRD peaks shifted to low angles and the surface roughness became non-uniform with an increase in the RF power. Also, the PL emission peak was red-shifted. The carrier density and the mobility decreased with the RF power. For the n-ZnO/p-GaN LED, the forward current at 20 V decreased and the threshold voltage increased with the RF power. The EL emission peak was observed at approximately 435 nm and the luminescence intensity decreased. Consequently, the crystallinity of the ZnO thin films grown with RF sputtering powers were improved. However, excess Zn affected the structural, electrical and optical properties of the ZnO thin films when the optimal RF power was exceeded. This excess RF power will degrade the characteristics of light emitting devices.

In this study, GaN powders were synthesized from gallium oxide-hydroxide (GaOOH) through an ammonification process in an NH3 flow with the variation of B2O3 additives within a temperature range of 300-1050˚C. The additive effect of B2O3 on the hexagonal phase GaN powder synthesis route was examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transformation infrared transmission (FTIR) spectroscopy. With increasing the mol% of B2O3 additive in the GaOOH precursor powder, the transition temperature and the activation energy for GaN powder formation increased while the GaN synthesis limit-time (tc) shortened. The XPS results showed that Boron compounds of B2O3 and BN coexisted in the synthesized GaN powders. From the FTIR spectra, we were able to confirm that the GaN powder consisted of an amorphous or cubic phase B2O3 due to bond formation between B and O and the amorphous phase BN due to B-N bonds. The GaN powder synthesized from GaOOH and B2O3 mixed powder by an ammonification route through β-Ga2O3 intermediate state. During the ammonification process, boron compounds of B2O3 and BN coated β-Ga2O3 and GaN particles limited further nitridation processes.

The purpose of this study is to investigate that the evaluation of odor analysis is affected by the classification of the agency and the general properties of the odor analysts, including gender, age, smoking behaviour, the number of participation in odor assessment, etc, so as to improve reliability and skills in terms of the result of complex odors by the air dilution methods. The sample for complex odor used the field sample which aimed at the odor analysts in the agency. The general characterizations of the odor analysts have affected the results of the odor analysis. The values of odor evaluation obtained by female odor analysts were more delicate than male, and the value of the result was reduced when above 40 s analysts conducted the evaluation. Moreover, Non-smokers perceived odor more sensitive than smokers. The more experience of odor analysis odor analysts had, The less values of the result were assessed. On the other hand, there are no differences in the value of odor evaluation depending on theclassification of institutions that participate in odor investigation. In conclusion, the selection of odor analysts considered gender, age, smoking behavior, and experience may be required to determine the improved reliability of data in odor evaluation. Ideally, Non-smokers 20~40 years old who have no dysfunction for the olfactory sense can be suitable for being optimal odor analyst.

The purpose of this study is to investigate the crystalline structure and optical properties of (GaZn)(NO) powders prepared by solid-state reaction between GaOOH and ZnO mixture under NH3 gas flow. While ammoniation of the GaOOH and ZnO mixture successfully produces the single phase of (GaZn)(NO) solid solution within a GaOOH rich composition of under 50 mol% of ZnO content, this process also produces a powder with coexisting (GaZn)(NO) and ZnO in a ZnO rich composition over 50 mol%. The GaOOH in the starting material was phase-transformed to α-, β-Ga2O3 in the NH3 environment; it was then reacted with ZnO to produce ZnGa2O4. Finally, the exchange reaction between nitrogen and oxygen atoms at the ZnGa2O4 powder surface forms a (GaZn)(NO) solid solution. Photoluminescence spectra from the (GaZn)(NO) solid solution consisted of oxygen-related red-emission bands and yellow-, green- and blue-emission bands from the Zn acceptor energy levels in the energy bandgap of the (GaZn)(NO) solid solutions.

ZnO thin films were grown on a sapphire substrate by RF magnetron sputtering. The characteristics of the thin films were investigated by ellipsometry, X-ray diffraction (XRD), atomic force microscopy (AFM), photoluminescence (PL), and Hall effect. The substrate temperature and growth time were kept constant at 200˚C at 30 minutes, respectively. The RF power was varied within the range of 200 to 500 W. ZnO thin films on sapphire substrate were grown with a preferred C-axis orientation along the (0002) plan; X-ray diffraction peak shifted to low angles and PL emission peak was red-shifted with increasing RF power. In addition, the electrical characteristics of the carrier density and mobility decreased and the resistivity increased. In the electrical and optical properties of ZnO thin films under variation of RF power, the crystallinity improved and the roughness increased with increasing RF power due to decreased oxygen vacancies and the presence of excess zinc above the optimal range of RF power. Consequently, the crystallinity of the ZnO thin films grown on sapphire substrate was improved with RF sputtering power; however, excess Zn resulted because of the structural, electrical, and optical properties of the ZnO thin films. Thus, excess RF power will act as a factor that degrades the device characteristics.

콩 씨스트 선충은 콩 수량에 가장 심각한 피해를 입히는 선충이며, 콩 씨스트 선충으로 입는 피해가 연 간 전 세계적으로 9백만 메가그램이나 되는 것으로 추정되고 있다. 콩 씨스트 선충은 식물 영양분을 먹어 뿌리의 성장을 지연시키고 근류균의 고정을 억제함으로서 수량의 감소를 가져 오게 된다. 콩 씨스트 선충을 방제하는 근본적인 방법은 저항성 품종을 재배하거나 윤작을 하는 것이다. 유전적으로 콩 씨스트 선충의 다양한 레이스들과 상업적 품종들의 제한된 저항성 품종들이 오랜 시간에 걸쳐 레이스 전환을 가져왔고, 이러한 이유로 콩 씨스트 선충의 방제가 매우 어려운 실정이다. 이 논문은 콩의 중요성, 콩 씨스트 선충, 콩 씨스트 선충 저항성에 대한 연구현황, 그리고 전망에 관해 고찰하였다.

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.