• Journal of Preventive Medicine and Public Health
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• 제41권3호
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• pp.195-199
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• 2008

Objectives : Malondialdehyde (MDA), a lipid peroxidation by-product, has been widely used as an indicator of oxidative stress. Urinary 2-naphthol, a urinary PAH metabolite, is used as a marker of ambient particulate exposure and is associated with lung cancer and chronic obstructive pulmonary disease. However, the stability and intra-individual variation associated with urinary MDA and 2-naphthol have not been thoroughly addressed. The objective of this study was to assess the stability and intra-individual variation associated with urinary MDA and 2-naphthol. Methods : Urine samples were collected from 10 healthy volunteers (mean age 34, range $27{\sim}42$ years old). Each sample was divided into three aliquots and stored under three different conditions. The levels of urinary MDA and 2-naphthol were analyzed 1) just after sampling, 2) after storage at room temperature ($21^{\circ}C$) for 16 hours, and 3) after storage in a $-20^{\circ}C$ freezer for 16 hours. In addition, an epidemiological study was conducted in 44 Chinese subjects over a period of 3 weeks. The urinary MDA and 2-naphthol were measured by HPLC three times. Results : There was no difference in the levels of urinary MDA and 2-naphthol between the triplicate measurements (n=10, p=0.84 and p=0.83, respectively). The intra-class correlation coefficients (ICC) for urinary MDA and 2-naphthol were 0.74 and 0.42, respectively. However, the levels of PM2.5 in the air were well correlated with the levels of both MDA and 2-naphthol in the epidemiological study. Conclusions : These results suggest that urinary MDA and 2-naphthol remain stable under variable storage conditions, even at room temperature for 16 hours, and indicate that these markers can be used in epidemiological studies involving various sample storage conditions. The intra-CC of urinary 2-naphthol and MDA were acceptable for application to epidemiological studies.

• 한국응용곤충학회지
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• 제40권3호
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• pp.235-243
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• 2001

파밤나방(Spodoptera exigua(Hubner))의 유전변이가 다형 동위효소를 이용하여 분석되었다. 집단들은 다른 기주, 지리적 위치, 그리고 시기에 따라 세분화되었다. 평균 이형접합자빈도($0.443\pm$0.013)는 파밤나방 전체 집단의 높은 유전변이를 나타냈다. 각 소집단들은 모두 Hardy-Weomberg 균형에서 벗어난 뚜렷한 동계교배 양식을 보였다. 이러한 높은 동계교배 효과는 지역고립에 의한 집단간 분화보다는 대부분 소집단 내 표본 추출 효과에 기인된 비임의교배에 의해 야기되었다. Wright($F_{ST}$ ) 와 Nei의 유전거리(D)는 소집단들간 유전적 분화가 낮음을 나타내지만, 일부 남쪽지역의 소집단들(해남과 사천)은 상대적으로 북쪽의 소집단들(안동과 군위)과 차이를 보였다. 유전적 거리를 기초하여 추정된 세대당 이주 개체수는 서로 다른 기주 집단간 5.9마리, 지역 집단간 10.6마리, 시기 집단간 31.8마리였다. 이러한 유전분석 결과들을 보아 국내 파밤나방은 이들의 탁월한 집단간 이주 능력 때문에 집단간 유전분화가 적은 것으로 나타냈다.

• 한국의상디자인학회지
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• 제15권1호
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• pp.75-89
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• 2013

The purpose of this study is to verify the mediating effect of store benevolence for impact on store loyalty of store environment and store personality. For this study, data were collected through questionnaires. The survey ran from March to May, 2011, the total of 330 respondents was used in analysis. The subjects consisted of adults living in the Daegu and Gyeongsangbuk-do region, and convenience sampling. For statistical analysis, SPSS 19.0 were used to verify the study model. The major results of the study show that store benevolence may play a linkage role of store environment, store personality on store loyalty. The store benevolence variable has the effect of partial mediation. The analysis of relationship between the variables of store environment (convenience, information service accessibility, accessibility, variation) and the store type show significant differences store environment (convenience, information service and the store type). The analysis of relationship between the variables of store personality(warm, fun, sophisticated, forward-looking) and the store type show significant differences store personality (warm, fun, sophisticated, forward-looking) and store type. The analysis of relationship between the variables of store environment(convenience, information service accessibility, accessibility, variation), and the demographic variables show significant differences in store environment (information service accessibility) regarding only age. The analysis of relationship between the variables of store personality(warm, fun, sophisticated, forward-looking) and the demographic variable show significant differences in store personality(warm) regarding only age (accessibility, accessibility, variation).

• 자원환경지질
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• 제41권4호
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• pp.393-403
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• 2008

이 연구는 우리나라의 농촌지역에서 유기비료로 살포되는 축산 분뇨가 농경지 지하수의 수질과 오염에 미치는 영향을 시공간적 변화를 중심으로 규명하기 위하여 수행되었다. 연구는 경기도의 한 농경지에서 200길 2월, 4월, 6월, 10월에는 관측정을 통한 지하수위 관측과 함께 지하수질 모니터링을 수행하였다. 그 결과 봄-여름-가을로 이어지는 계절과 축분을 뿌리는 시기에 따라서 지하수의 수질과 오염현상의 변화는 축분을 가장 많이 뿌리는 시기인 4월에 질산성 질소 농도가 가장 높게 나타났다. 그리고 지하수 내 Mn, Fe 등의 농도와 용존 유기물함량(DOC) 등을 모니터링 함으로써 천부 지하수의 산화-환원상태와 대수층 내 미생물의 활성도가 연구부지 지하수 내 질산성 질소의 농도변화에 가장 중요한 요인으로 작용하는 것으로 유추할 수 있다.

• Journal of Forest and Environmental Science
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• 제39권1호
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• pp.13-19
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• 2023

We investigated Soil respiration in Bluepine forest of western Bhutan, in relation to soil temperature, moisture content and soil pH and it was aimed at establishing variability in space and time. The Bluepine forest thrives in the typical shallow dry valleys in the inter-montane Bhutan Himalaya, which is formed by ascending wind from the valley bottom, which carries moisture from the river away to the mountain ridges. Stratified random sampling was applied and the study site was classified into top, mid, low slope and further randomized sample of n=20 from 30 m×30 m from each altitude. The overall soil respiration mean for the forest was found 2248.17 CO₂ g yr^-1 and it is ~613.58 C g yr^-1. The RS from three sites showed a marginal variation amongst sites, lower slope (2,309 m) was 4.64 μ mol m^-2 s^-1, mid slope (2,631 m) was 6.78 μ mol m^-2 s^-1 and top slope (3,027 m) was 6.33 μ mol m^-2 s^-1 and mean of 5.92 μ mol m^-2 s^-1, SE=0.25 for the forest. Temporal distribution and variations were observed more pronounced than in the space variation. Soil respiration was found highest during March and lowest in September. Soil temperature had almost inverse trend against soil respiration and dropped a low in February and peak in July. The moisture in the soil changed across months with precipitation and pH remained almost consistent across the period. The soil respiration and soil temperature had significant relationship R²=-0.61, p=0.027 and other variables were found insignificant. Similar relationship are reported for dry season in a tropical forest soil respiration. Soil temperature was found to have most pronounced effect on the soil respiration of the forest under study.

• Asian Journal of Atmospheric Environment
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• 제7권2호
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• pp.65-71
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• 2013

Japanese cedar (Cryptomeria japonica) pollinosis is the most popular pollinosis in Japan. It has been reported that Cryptomeria japonica pollen allergenic species are suspended as fine particles in the urban atmosphere. These allergenic fine particles are responsible for inducing asthma by breaking into the lower respiratory tract. It has also been found that pollinosis symptoms on the sufferers appear mainly at night-time by the results from epidemiological studies. However, the exact reason for these phenomena is not yet clarified. In this study, the diurnal and nocturnal behaviours of Cryptomeria japonica pollen grains and their allergenic species in the urban area of Saitama city of Kanto Plain were investigated. Airborne pollen grains and allergenic Cry j 1 concentrations in total suspended particulate matter (TSP) were investigated at two sampling sites, a heavy traffic road (roadside site) and at the balcony of the $10^{th}$ floor of the Building of Research and Project of Saitama University (general urban site). The latter sampling site where located about 300 m away from the roadside site was used as a general urban site unaffected by automobile traffic. The airborne pollen counts were measured with a real-time pollen monitor. Cry j 1 particles were collected with two high volume air samplers, and these concentrations were measured by surface plasmon resonance method with a Biacore J system. The diurnal variation of the airborne pollen counts was similar to the trends of temperature and wind speed during the day-time; whereas its tendency with wind speed trend was not observed during the night-time. Airborne pollen counts were lower with northern wind than with southern wind because the pollen comes from the mountainous areas, and the mountains in the south are closer, about half the distance to the northern mountains. It is suggested that the peaks of airborne pollen counts during night-time in the sampling site occurred by transport of pollen grains released during day-time in the mountainous forest areas, located c.a. 100 km away from the sampling site. On the roadside site the allergenic Cry j 1 concentrations were higher than at the general urban site, nevertheless pollen grains counts were lower. These results suggested that worsening of pollinosis symptoms during night-time in urban area was caused by transport of pollen grains during day-time in the mountainous forest areas. Moreover, pollen allergenic species become different morphology from pollen grain at roadside site, and the subsequent pollen grains re-suspension by automobile traffic.

• 대한환경공학회지
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• 제28권8호
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• pp.878-883
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• 2006

망간코팅모래(MCS)와 철코팅모래(ICS) 21.5 kg씩 동량을 하부 및 상부층으로 2단 충진시킨 파일럿 규모의 여과시스템을 구성하여 3가 비소 함유 인공오염수 처리효율을 조사하였다. 파일럿 장치는 높이 200 cm와 내경 15 cm로 구성되어 있으며, 3가 비소함유 인공 오염수의 반응기 칼럼내 유입은 peristaltic pump를 사용하여 선속도 $5{\times}10^{-3}$ cm/s로 상향류로 시켰으며 148일 동안 여과실험을 실시하였다. MCS 통과지점(중간유출수)과 ICS 통과지점(최종 유출수)에서의 총 비소의 파과는 각각 18일 및 44일 경과 후에 이루어졌고 그 이후 파과가 급격히 진행되었으며 148일이 지났을 때 완전파과가 발생하였다. 비록 MCS 층을 통과한 유출수에서의 총 비소파과는 18일 경과 후에 나타났지만 유출수내의 3가 비소 농도는 61일 동안 50 ppb 이하로 나타났으며 이후에는 급격히 증가되어 나타났다. 이것은 칼럼에 충진된 MCS가 61일 동안 효과적으로 3가 비소에 대한 산화력을 나타내기 때문에 기인한 것이며 MCS 1 kg당 3가 비소 92 mg을 산화처리 함을 나타낸다. 그리고 완전파과가 발생할 때 까지 MCS에 의해서 흡착된 총 비소의 양은 MCS 단위 kg 당 79.0 mg에 해당하였다. 운전기간 동안 반응탑내의 각 지점에서의 시간에 따른 수두의 변화는 크게 나타나지 않아서 ICS 및 MCS를 갖춘 여과시스템은 큰 수두손실 없이 오염수를 장기간 처리할 수 있음을 알 수 있었다.

• 한국대기환경학회지
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• 제22권2호
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• pp.259-266
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• 2006

A dual-channel glass coil sampling technique was used to measure hourly formaldehyde concentration in the ambient air. The dual-channel coil sampling assembly consists of three parts; an all-pyrex 28-turn coil made of 0.2-cm internal diameter glass tubing for gas-liquid contact and scrubbing of soluble gases, an inlet section upstream of the coil for introducing sample air and scrubbing solution, and a widened glass section downstream of the coil for gas-liquid separation. The scrubbing solution used was a dilute aqueous DNPH (dinitrophenylhydrazine) solution. Hourly concentration of formaldehyde was determined at a Gwangju semi-urban site during two intensive studies between September and October using the dual channel glass-coil/DNPH sampling technique and HPLC (High Performance Liquid Chromatography) analysis. The mean concentration was 1.7($0.4{\sim}4.7$) and 3.0($0.5{\sim}19.1$) ppbv for the September and October intensives, respectively, which are considerably low, compared to those measured in polluted urban areas around the world including several urban areas of Korea. The diurnal variation showed significant increase of formaldehyde in the daytime suggesting the dominance of formation of formaldehyde due to photochemical oxidation of methane and other hydrocarbons. An increase in the formaldehyde sometimes in the night might be due to an increase in primary source, i.e. traffic emissions. It was also found that rapid increase in formaldehyde levels from 3.0 to 19.1 ppbv in the afternoon on October 20 was due to plumes from burning of agricultural wastes such as rice straw and stubble. It is expected from the measurement data that the constructed dual-channel glass coil sampling system can be utilized for measuring atmospheric concentration of the formaldehyde with high time resolution.

• 한국통신학회논문지
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• 제32권7A호
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• pp.672-677
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• 2007

전광 EO-MZ 광변조기의 바이어스를 안정화함으로써 버스트 모드 패킷 트래픽 조건에서도 스위칭 소광비를 최대화하는 방법을 제안하고 입증하였다. 광변조기의 오프 레벨 출력 전력을 샘플링하고 최소화함으로써 패킷 트래픽 밀도의 변화에 무관하게 높은 소광비를 갖는 광 게이트로서 동작한다.

• 한국산업보건학회지
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• 제20권4호
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• pp.241-247
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• 2010

Recently, indoor air quality (IAQ) has been one of the major concerns of people. Indoor parking lots are subject to be exposed to high concentrations of air pollutants emitted from vehicles. This study was performed to investigate indoor air quality (IAQ) at indoor parking lots. Sampling sites were selected 5 indoor parking lots. Target indoor air quality parameters include a number of criteria pollutants such PM$_{10}$, CO, CO$_2$, and HCHO. In addition, a variation of IAQ according to ventilation system operating was measured at C site (underground parking lot). In general, all pollutants were maintained below indoor air quality maintenance standards. The indoor air quality at indoor parking lots was affected by the availability of the ventilation facility and their operation frequency. At the underground parking lot (C site) with ventilation system, TVOC concentration according to ventilation system operating were found to be lower operating (488.2 ${\mu}g/m^3$) than non-operating (1,401.2 ${\mu}g/m^3$).