• 분석과학
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• 제30권4호
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• pp.182-193
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• 2017

In order to examine the variation characteristics of chemical compositions in relation to the inflow pathways of Asian dust, $PM_{10}$ and $PM_{2.5}$ aerosols were collected at Gosan site of Jeju Island during the Asian dust days between 2010 and 2015, and their chemical compositions were analyzed. The mean mass concentrations of $PM_{10}$ and $PM_{2.5}$ during Asian dust days were $130.0{\pm}90.2$ and $38.2{\pm}24.7{\mu}g/m^3$, respectively. The composition ratios of major secondary pollutants ($nss-SO_4{^{2-}}$, $NH_4{^+}$, $NO_3{^-}$) were high as 53.7 % for $PM_{10-2.5}$ and 90.6 % for $PM_{2.5}$. When the Asian dusts had been transported to the Korean Peninsula via Loess Plateau of central China, the concentrations of $nss-Ca^{2+}$, $NH_4{^+}$, $nss-SO_4{^{2-}}$, and $NO_3{^-}$ increased more noticeably. Whereas in case when the inflow pathways of Asian dust had been through the Bohai bay, the concentrations of the crustal species such as Al, Fe, and Ca were relatively high in coarse particles. The atmospheric aerosols were acidified largely by sulfuric and nitric acids. They were neutralized mainly by calcium carbonate in coarse particle mode passed through Manchuria area, but by ammonia in fine particle mode passed through Loess plateau and Bohai bay. Ammonium salts are assumed to exist as ammonium sulfate and ammonium nitrate in coarse particles, but mostly as ammonium sulfate in fine particles.

• 대한지하수환경학회지
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• 제3권2호
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• pp.70-79
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• 1996

Friar Turk 폐탄광은 미국중서부의 가장복잡하게 교란된 광산 중의 하나이다. 버럭 및 광미 속에는 고농도의 황철석이 함유되어 있고, 황철석의 산화작용에 의해 토양 및 물이 산성화되고 식물의 성장이 제한되고 있다. 복구기술들에 대한 효과를 정량적으로 평가하기 위한 노력으로, 상세한 관측프로그램이 수행되었다. 물 시료들은 지표수, 지하수 및 불포화대의 간극수에서 5년간에 걸쳐 채취되었다. 그 결과에 의하면, spoil은 미약한 물 오염원이고, 버럭 더미는 지표수 및 지하수를 심각하게 오염시키는 원천이다. 그러나 버럭 더미 하부에 분포하는 loess 및 till은 오염된 물이 이동하는 것을 효과적으로 억제하였다. 버럭 더미 및 광미 표면층들은 수십 년간에 걸쳐 풍화된 결과로 층 내부보다는 독성이 약하였다. 산성광산폐수의 생성은 정점에 달한 상태이며 잠재적인 산성층은 아마도 광산폐기물의 불포화대에 분포하는 것으로 사료된다.

• 한국대기환경학회지
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• 제16권5호
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• pp.487-497
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• 2000

Spring time is a favorable season to be easily observed the Yellow Sand phenomenon in East Asia. In particular most of the phenomenon tend to occur in April. However, Yellow Sand phenomenon was observed from almost the whole country of Korea in winter of 1966, 1977 and 1999. The features of the synoptic weather pattern in the source regions, air stream flow between the source region and Korea, the measurement of TSP concentration, aerosol size distribution, and chemical composition of snow samples associated with Yellow Sand phenomenon were investigated. The result showed the characteristic evolutionary feature of the synoptic system associated with Yellow Sand phenomena, that is, a strong low level wind mobilized the dust within 2 or 3 days before Yellow Sand phenomenon being observed in Seoul. The wind was remarkably intensified in the source region on January 24, 1999 under the strong pressure gradient, A trajectory analysis showed that the Yellow Sand particle could be reached to Korea within 2 days from the source region, Gobi desert, through Loess plateau and Loess deposition region. The TSP concentration at the top of Kwanak mountain during the Yellow Sand phenomenon is abruptly increasing than the monthly mean concentration. The size resolved number concentration of aerosols ranging from 0.3 to 25${\mu}{\textrm}{m}$ was analyzed during Yellow Sand episode. It was evident that aerosols were distinguished by particles in the range of 2-3 ${\mu}{\textrm}{m}$ to result in the abrupt increase in January 1999, After Yellow Sand phenomenon, there was heavy snow in Seoul. By the analysis of snow collected during that time, it was observed that both the Ca(sup)2+ concentration and pH were increased abnormally compared to those in the other winter season.

• 대한임상검사과학회지
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• 제49권4호
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• pp.337-344
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• 2017

To date, no clear threshold that has been established for defining an adequate store of vitamin D for bone health. Therefore, this study aims to determine the required level of vitamin D to maintain a healthy skeleton based on bone remodelling process among healthy adult population. This was a cross sectional study, involving a healthy adult population in Kota Bharu, Malaysia, aged 18~50 years. We measured serum 25(OH)D (vitamin D), serum parathyroid hormone (PTH), serum C-terminal telopeptide of type 1 collagen (CTX), and Procollagen 1 Intact N-Terminal (P1NP) in 120 healthy adults selected via multi stage sampling (64 males, 56 females) from 6 subdistricts in Kota Bharu. The mean level of 25(OH)D was 23.50 (${\pm}8.74$) nmol/L. There was a significant difference of the vitamin D level between genders ($26.81{\pm}8.3nmol/L$ vs $19.72{\pm}7.68nmol/L$ in males and females respectively) (p value<0.001). More than 50% of female subjects had 25(OH)D less than 20 nmol/L, while only 20.3% of male subjects had 25(OH)D below 20 nmol/L. Based on the LOESS plot, the bone turnover markers showed a plateauing result, at the 25(OH)D level of 35 nmol/L for CTX and 20 nmol/L for P1NP. Contrastingly, PTH showed a step rise in the 25(OH)D level of 20 nmol/L. Based on the LOESS plot for CTX, P1NP and PTH versus 25(OH)D, level of vitamin D between 20 to 35 nmol/L is recommended to maintain healthy skeleton.

• 한국건설순환자원학회논문집
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• 제10권4호
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• pp.498-505
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• 2022

본 연구에서는 Living Concrete의 품질특성 평가결과 유동성은 황토 혼합율 증가에 따라 테이블 플로우가 감소하는 경향이 나타났으며, 압축강도는 황토 혼합율 증가에 따라 감소하는 것으로 나타났다. 경량화를 위하여 밀도 특성 평가를 실시하였으며, 비교군으로 시멘트를 사용한 패널과 비교한 결과 시멘트 패널의 밀도에 비해 약 20 % 낮은 밀도가 측정되어 하중에 영향을 적게 받아 구조물에 설치가 가능할 것으로 판단된다. 패널온도 저감성을 평가한 결과 시간에 따른 온도 저감의 차이가 나타났으며, 이끼가 착근된 패널이 이끼가 착근되지 않은 패널보다 온도의 저감이 나타나 수직형 녹화시스템에 활용이 가능할 것으로 판단된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.325-331
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• 2006

Various environmental conditions affecting total phosphorus removal from farm wastewater in a biofilm filter process were investigated using loess balls and Chromobacterium LEE-38 at a pilot plant. When Chromobacterium LEE-38 was used, the removal efficiency of total phosphorous was approximately 10- or 5-fold higher than that of Acinetobacter CHA-2-14 or Acinetobacter CHA-4-5, respectively. When a loess ball of $11{\sim}14mm$ manufactured at a $960^{\circ}C$ calcining temperature was used, the removal efficiency of total phosphorous was 90.0%. When 70% of the volume fraction was used, the maximum efficiency of total phosphorus removal was 93.1%. Notably, when the initial pH was in the range of 6.0 to 8.0, the maximum removal efficiency of total phosphorus was obtained after 30 days. When the operating temperature was in the range of 30 to $55^{\circ}C$, the maximum removal efficiencies of total phosphorus, 95.6 to 94.6%, were obtained. On the other hand, at operating temperatures below $20^{\circ}C$ or above $40^{\circ}C$, the removal efficiency of total phosphorous decreased. Among the various processes, biofilm filter process A gave the highest removal efficiency of 96.4%. Pilot tests of total phosphorus removal using farm wastewater from the biofilm filter process A were carried out for 60 days under optimal conditions. When Acinetobacter sp. Lee-11 was used, the average removal efficiency in the p-adsorption area was only 32.5%, and the removal efficiencies of chemical oxygen demand (COD) and biological oxygen demand (BOD) were 56.7 and 62.5%, respectively. On the other hand, when Chromobacterium LEE-38 was used, the average removal efficiency was 95.1%, and the removal efficiencies of COD and BOD were 91.3 and 93.2%, respectively.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.343-347
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• 2003

황토볼을 이용하여 폐수처리를 한 결과 다음과 같은 결과를 보였다. 흐름도 A에서는 T-P 0.5ppm이하, T-N 1.0 ppm이하, COD 10ppm 이하였으며, 흐름도 B에서는 T-P 0.3ppm이하, T-N 5.0 ppm이하, COD 15 ppm 이하의 결과를 보여 주었다. 흐름도 C에서는 T-P 0.6ppm이하, T-N 10 ppm이하, COD 15 ppm 이하였으며, 흐름도 D에서는 T-P 1 ppm, T-N 8 ppm이하, COD 20ppm 이하의 결과를 보여 주었다. BOD는 각 흐름도 A, B, C, D에서 COD보다 높은 경우에는 6 ppm, 낮은 경우에는 3 ppm 정도의 차이를 보였다. SS는 각 공정에 따라 그다지 큰 차이를 보이고 있지 않으며, 1.0 처리 용량 Ton/day으로 계산 할 경우에 5 - 20 g/day 정도를 보이고 있다. 이러한 결과치는 하수종말처리장(특별대책지역 및 잠실수중보권지역)의 2 ppm 및 폐수처리시설(농공단지, 오${\cdot}$폐수처리시설 포함)의 T-P 8 ppm, T-N 질소성분 60 ppm이내의 탄소원 COD 40 ppm 이내의 기준에 해당하는 수치의 좋은 결과로 황토볼을 이용한 폐수처리 시스템의 가능성을 보여주고 있다.

• 농업과학연구
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• 제41권3호
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• pp.169-175
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• 2014

Objective of this study was to investigate effects of pre-processing method and number of sampling leaves on stability of the reflectance measurement for Chinese cabbage and kale leaves. Chinese cabbage and kale were transplanted and cultivated in a plant factory. Leaf samples of the kale and cabbage were collected at 4 weeks after transplanting of the seedlings. Spectra data were collected with an UV/VIS/NIR spectrometer in the wavelength region from 190 to 1130 nm. All leaves (mature and young leaves) were measured on 9 and 12 points in the blade part in the upper area for kale and cabbage leaves, respectively. To reduce the spectral noise, the raw spectral data were preprocessed by different methods: i) moving average, ii) Savitzky-Golay filter, iii) local regression using weighted linear least squares and a $1^{st}$ degree polynomial model (lowess), iv) local regression using weighted linear least squares and a $2^{nd}$ degree polynomial model (loess), v) a robust version of 'lowess', vi) a robust version of 'loess', with 7, 11, 15 smoothing points. Effects of number of sampling leaves were investigated by reflectance difference (RD) and cross-correlation (CC) methods. Results indicated that the contribution of the spectral data collected at 4 sampling leaves were good for both of the crops for reflectance measurement that does not change stability of measurement much. Furthermore, moving average method with 11 smoothing points was believed to provide reliable pre-processed data for further analysis.

• 방사성폐기물학회지
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• 제16권2호
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• pp.183-193
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• 2018

현재, 한국원자력연구원은 부산 기장에 연구용 원자로(Ki-Jang Research Reactor, KJRR)를 건설 계획하고 있다. 원자로를 운영하면 중 저준위 방사성폐기물이 발생하므로 방사성 폐기물을 안전하게 처리 하는 것이 중요하다. 현재, 다양한 형태의 방사성 폐기물을 처리 할 수 있는 시멘트 고화 방법을 일반적으로 사용하고 있으며, 방사성 폐기물 처분시설 인수 기준(압축 강도, 유리수, 침수 및 침출시험 등)을 만족해야 한다. 특히, 폐기물에 함유된 방사성 세슘이 유출 될 경우 범 국제적인 문제를 야기하므로, 고화체 인수 기준 중에서 침출시험이 가장 중요한 인자이다. 시멘트 고화 방법은 다른 고화 방법 보다 공정이 간단하며 비용이 적게 들지만, 침출 저항성이 낮다. 이에 본 연구는 시멘트 고화체 세슘 침출 저항성 증진을 위하여 기장 연구용 원자로(KJRR) 모사폐액과 대표적인 세슘 흡착제인 제올라이트와 황토를 혼합하여 기장로 모의폐액 시멘트를 제조하였다. 제올라이트와 황토가 시멘트 고화체와 결합되어 있는 것을 SEM-EDS를 통하여 정량적으로 확인하였다. 침출 시험은 ANS 16.1 방법에 의해 90일동안 진행하였다. 기장로 모의폐액 시멘트의 세슘(3000 ppm)을 첨가하여 90일간의 침출시험 후 침출수의 세슘 농도 분석 결과, 제올라이트와 황토가 포함된 모의폐액 시멘트는 제올라이트와 황토를 첨가하지 않은 대조군에 비해 최대 27.90%, 21.08%의 세슘 침출 저항성 정도를 나타내는 것을 확인하였다. 또한, 제올라이트와 황토가 포함된 기장로 모의폐액 시멘트는 인수 기준(압축강도, 유리수 유무, 침수 및 침출 지수)을 통과 하는 것을 확인하였다.

• 응용통계연구
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• 제21권1호
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• pp.169-176
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• 2008

일반화선형모형 에서 추가되는 설명 변수의 비선형성의 존재와 형태를 파악하는데 사용되는 3차원 CBRBS그림의 구조와 유용성에 대해 알아본다. CBRBS그림은 설명변수들 사이에 비선형의 관계가 존재하는 경우 편잔차그림으로는 알아낼 수 없는 비선형성에 대한 탐지가 가능하다. 이를 생성된 자료를 이용하여 확인해 본다.