• 제목/요약/키워드: PM mass ratio

검색결과 303건 처리시간 0.024초

서울.아산지역 호흡성먼지의 금속함량에 관한 연구 (Comparison of Metal Contents in Respirable Particulate Mass by Particle Size and Season in Seoul and Asan City)

  • 최윤나;전용택;장봉기;양원호;염윤기;손부순
    • 환경위생공학
    • /
    • 제23권1호
    • /
    • pp.33-48
    • /
    • 2008
  • The purpose of this study was to characterize background mass concentration of $PM_{10},\;PM_{2.5}$ and metallic composition from June 2004 to June 2005 in comparison with Seoul and Asan city. The results were as follows: 1. Annual mean of $PM_{10}$ concentrations in Seoul and Asan were $56.95({\pm}25.63){\mu}g/m^3,\;57.02({\pm}27.22){\mu}g/m^3$ respectly. 2. Annual mean of $PM_{2.5}$ concentrations in Seoul and Asan were $46.97({\pm}40.36){\mu}g/m^3,\;42.16({\pm}21.79){\mu}g/m^3$ respectly. 3. The average $PM_{2.5}/PM_{10}$ ratio was 0.82 in Seoul and 0.74 in Asan city. 4. The concentration of $PM_{10},\;PM_{2.5}$ were the highest in spring and the lowest in summer. Asan was higher than Seoul in spring and summer. 5. The results showed that average $PM_{10}$ composition order as Si>Fe>Pb>Zn>Mn in Seoul and Si>Fe>Zn>Pb>Mn in Asan. The concentration of metals in $PM_{10}$ of Seoul that Cr, Cu, Fe, Mn were high in spring and Zn was low in Fall. Fe, Mn were high in spring of Asan. 6. The results showed that average $PM_{2.5}$ composition order as Si>Pb>Fe>Zn>Mn in Seoul and Si>Fe>Pb>Zn>Cr in Asan. The concentration of metals in $PM_{2.5}$ of Seoul that Cr was high in spring. 7. The result showed that relation between Cr and Cu, Cu and Fe, Fe and Mn, Mn and Zn, Zn and Si in Seoul, Cr and Zn, Cu and Pb, Zn and Pb, Pb and Mn in Asan. The result showed that $PM_{10}$ concentration exceeding $50{\mu}g/m^3$(US-EPA Standard) and $PM_{2.5}$ concentration exceeding $15{\mu}g/m^3$(US-EPA Standard). In urban area, the monitoring of $PM_{2.5}$ permits the anthropogenic sources and the interference of natural sources with respect to $PM_{10}$ measurements.

측방가압충전시 Heated Spreader 사용유무가 근관밀폐에 미치는 영향 (INFLUENCE OF HEATED SPREADER ON THE SEALING ABILITY OF LATERAL CONDENSATION)

  • 정원균;홍찬의
    • Restorative Dentistry and Endodontics
    • /
    • 제24권1호
    • /
    • pp.222-232
    • /
    • 1999
  • The purpose of this study was to evaluate the effect of heated spreader on the sealing ability of lateral condensation, compared with regular cold spreader. Forty two extracted human teeth with single canal were randomly placed into 3 experimental groups, and four additional teeth were used as positive and negative controls. Each group was prepared with Ni-Ti Profile #40 using step-down technique and obturated with standardized colored gutta-percha cone by standard(cold) lateral condensation technique, warm lateral condensation technique with Endotec and hot spreader soaked in glass bead sterilizer, each with Sealapex sealer. Control groups were not obturated, but prepared. After 2 days in 2% methylene blue, the teeth were invested and made into transparent resin blocks. And then, each block was sectioned horizontally with microtome at 1, 2, 3, 4, 5 mm levels from the apex. The linear extent of dye penetration was examined with stereomicroscope at ${\times}$20 magnification. At each of 5 levels, ratio of the area of gutta-percha was obtained by calculating the area of gutta-percha to the total area of the canal. The data collected were then analyzed statistically using an analysis of variance(ANOVA) and Scheffe test. The results were as follows ; 1. All experimental groups produced the apical microleakage. 2. The mean leakage was 1.57${\pm}$0.76mm for cold spreader group, 0.86${\pm}$0.95mm for Endotec spreader group, and 0.64${\pm}$0.93mm for hot spreader group. The difference between hot spreader group and cold spreader group was statistically significant(p<0.05). 1. At the 1 mm level, the mean ratio of area of gutta-percha was 74.58${\pm}$13.15(%) for cold spreader group, 65.42${\pm}$14.62(%) for Endotec spreader group, and 80.72${\pm}$14.63(%) for hot spreader group. There was statistically significant difference between hot spreader group and Endotec spreader group(p<0.05). 2. At the 2mm level, the mean ratio of area of gutta-percha was 87.86${\pm}$11.22(%) for cold spreader group, 66.55${\pm}$14.02(%) for Endotec spreader group, and 92.93${\pm}$7.24(%) for hot spreader group. There was statistically significant difference between Endotec spreader group and other two spreader groups(p<0.05). 3. At the level 3, 4, 5 mm, there was no statistically significant difference between each group. Within the limits of the results of this experiment, warm lateral condensation technique with hot spreader soaked in a glass bead sterilizer demonstrated favorable apical sealing effect and improved density of gutta-percha mass. Thus, it is thought that this obturation technique is effective for clinical use and beneficial to reduce condensation forces, also economical and easy. Lateral condensation, Heated spreader, canal sealing, Microleakage.

  • PDF

수도권 지역의 탄소 성분 에어로졸 측정 연구: KORUS-AQ 2016 캠페인 기간을 중심으로 (A Study of Carbonaceous Aerosols Measurement in Metropolitan Area Performed during KORUS-AQ 2016 Campaign)

  • 정병주;배민석;안준영;이정훈
    • 한국대기환경학회지
    • /
    • 제33권3호
    • /
    • pp.205-216
    • /
    • 2017
  • Carbonaceous aerosols such as the equivalent black carbon (eBC), the elemental carbon (EC) and the organic carbon (OC) were monitored at the Seoul Olympic Park site ($37.521^{\circ}N$, $127.124^{\circ}E$) during the KORUS-AQ 2016 campaign using a Multi Angle Absorption Photometer (MAAP) and an OCEC Analyzer. Averaged mass concentrations of eBC, EC and OC were presented as $2.46{\pm}1.52{\mu}g/m^3$, $1.01{\pm}0.60{\mu}g/m^3$ and $4.85{\pm}2.60{\mu}g/m^3$, respectively. OC/EC ratio and mass absorption cross-section (MAC) of light absorbing aerosols were calculated as 2.32 and $14.8m^2/g$, respectively. Diesel OC concentrations were estimated from a source profile of diesel vehicles as well. eBC mass concentrations measured from May $26^{th}$ to May $27^{th}$, 2016 showed 40% higher than averaged eBC mass concentrations during campaign period. $PM_{2.5}$ concentrations measured in this period were also higher than average $PM_{2.5}$ concentrations. High eBC concentrations were observed from May $29^{th}$ to May $31^{st}$, 2016 and from June $9^{th}$ to June $11^{th}$, 2016, possibly due to morning rush hour and the effect of temperature inversion at night. Diurnal variations of eBC, EC and Diesel OC showed a typical pattern of metropolitan area. In the weekend, however, diurnal variations of eBC, EC and Diesel OC mass concentrations were different from those measured in the weekday. It is expected that this study can help to understand the relationship between carbonaceous aerosols in a metropolitan area.

화력발전소 굴뚝 미세먼지 측정을 위해 개발한 이젝터-다공튜브 희석장치의 희석비 검증 (Verification of dilution ratio of the newly developed ejector-porous tube diluter for measurement of fine dust in coal-fired power plant stack)

  • 신동호;김영훈;서현수;홍기정;김학준;김용진;한방우;이가영;천성남;황정호
    • 한국입자에어로졸학회지
    • /
    • 제15권3호
    • /
    • pp.105-113
    • /
    • 2019
  • The exhaust emissions from coal-fired power plants have received much attention because coal-fired power plants are the one of the largest sources of particulate matter (PM) emissions in South Korea. To measure the PM10 and PM2.5, we developed the novel diluter which is comprised of ejector and porous tube in series. The dilution ratio must be defined to calculate particle concentrations of the sampled air as well as to probe match for the isokinetic sampling. For this reason, we verified the dilution ratio of the developed diluter by the flow rate, numerical solution, gas concentration and particle concentration. The ejector-supplied flow rates were 10-50 L/min and the porous tube-supplied flow rates were 30, 50 L/min in this study. All methods above showed similar dilution ratios to each other within 10 % error rate. The dilution ratio was confirmed by comparing mass concentrations before and after the dilution process.

서울지역 여대생의 BMI를 기준으로 식생활, 영양섭취상태 및 혈액인자 비교 연구 (Comparison of the Dietary Pattern, Nutrient Intakes, and Blood Parameters According to Body Mass Index (BMI) of College Women in Seoul Area)

  • 최경순;신경옥;정근희
    • 한국식품영양과학회지
    • /
    • 제37권12호
    • /
    • pp.1589-1598
    • /
    • 2008
  • 본 연구는 $20{\sim}24$세의 여대생 대상으로 비만유형에 따라 각 군별로 식습관과 식생활 평가, 영양섭취상태 및 혈액인자가 건강에 어떠한 영향을 주는지를 조사하였다. 체질량지수 (BMI)에 따라 저체중군, 정상군, 비만군으로 분류하였을 때, 신장은 군 간에 유의적인 차이가 없었지만, 체중 골격근량 체지방량 제지방량 체지방률 및 waist-hip ratio는 비만군에서 가장 높았다(p<0.05). 조사대상자의 식습관은 매일 아침식사를 하는 경우는 129명 중 저체중군은 36명 27.9%, 정상군은 88명 68.2%, 비만군은 5명 3.9%로 나타났으며, 전체 조사대상자의 아침 식사의 결식률도 15.3%나 되었다. 아침 결식의 이유로는 아침시간이 바쁘거나, 늦게 일어나서 아침을 거르는 경우가 많았으며, 결식으로 인한 배고픔을 간식으로 대체하고 있어 하루에 $1{\sim}2$회 정도 간식을 한다고 답하였다. 식생활 평가를 보면, 저체중군에 속하는 여대생들은 육류, 생선, 알류 등의 단백질 식품의 섭취(23.4%)와 과일 및 과일주스의 섭취(37.8%)를 많이 하는 경향을 보였으며, 비만군에 속하는 여대생들은 삼겹살, 갈비 등 지방이 많은 육류를 주 2회 이상 먹는 비율(77.8%)과 김치 및 채소를 식사 때마다 먹는 비율(66.7%)이 다른 군에 비해 높았다(p<0.05).그러나 비만군에 속한 여대생의 경우 모든 식품을 골고루 섭취하려고 많은 노력을 하였으며, 저체중군에 비해 오히려 비만군에서 식생활과 건강에 더 많은 관심을 보이고 있는 것으로 나타났다. 영양소 섭취상태 중 콜레스테롤 섭취량은 오히려 다른 군에 비해 비만군에서 낮았고(p<0.05), 전체 여대생의 영양소 섭취상태를 한국인 영양섭취기준과 비교해 볼 때, 철, 칼슘, 섬유소의 섭취는 제시된 기준치에 비해 현저히 낮았으며, 소디움의 섭취는 오히려 기준치에 비해 과다하게 섭취하는 것으로 나타났다. 혈액 검사 결과 혈중 총 콜레스테롤, HDL-cholesterol 및 HDL-C/LDL-C(ratio)는 비만군에서 낮았으며, 중성지방 수치는 다른 두 군에 비해 비만군에서 매우 높은 수치를 나타내었다(p<0.05). 혈중 총콜레스테롤은 각각 HDL-cholesterol 및 LDL-cholesterol과 정의 상관관계를 보였으며, 중성지방은 HDL-cholesterol과 역의 상관관계를 보였다. 따라서 본 연구의 결과를 보면, BMI에 의해서 분류된 세 그룹 모두에서 아침 결식률과 운동부족이 문제가 있는 것으로 나타났다. 저체중군에서는 균형적인 영양섭취가 요구되는 것으로 나타났고, 비만군에서는 너무 본인의 신체적 문제를 의식하여 식품의 섭취에 있어서 균형적인 식사를 무시하고, 체중을 줄이려고 편식을 시도하려는 경향이 있는 것이 문제점으로 지적되었다. 따라서 저체중군, 정상군 및 비만군에 상관없이 여대생의 현실에 맞는 전반적인 식생활의 개선과 건강 증진을 위한 영양교육 강화의 필요성 및 체계적인 식사관리 프로그램이 요구됨을 알 수 있었다. 또한 비만인 뿐만 아니라 저체중의 비율도 높아 자신의 건강상태를 올바르게 판단하여 자신에게 맞는 식생활 계획을 세우는 것이 필요하다고 사료된다.

Estimation of Plant Seed Dispersal through Artificial Soil Movement in Incheon Urban Area

  • Kim, Kee-Dae
    • 환경생물
    • /
    • 제21권2호
    • /
    • pp.181-188
    • /
    • 2003
  • In this study, soil seed and bud bank analysis were performed to abbess the mass of potential vegetation in soils less than 1 year old after covered and estimate the amount of seed bank transport through construction in urban area. The ratio of exotic species number to total species number in study sites and the landfill control site was 0.29 and 0.39, respectively. All plots pooled, mean species number and total mean seedling density per $\m^2$ in the top 10 cm of soil was 11$\pm$0 (average$\pm$S.E.) and 8037$\pm$221.Total plant seeds by artificial soil trasnsfer were estimated to be 53 thousand million $m^{-2}yr^{-1}$ in 10 cm soil depth. It reveals that soil transfer accelerates seeds and vegetation movement and makes urban vegetation mixed and common.

연무 에어로졸의 조성 및 기류 유입경로별 변화: 2012-2013년 제주도 고산지역 측정 (Compositions of haze aerosols and their variation by inflow pathway of air mass at Gosan site in Jeju Island during 2012-2013)

  • 현동림;송정민;김기주;김원형;강창희;고희정
    • 분석과학
    • /
    • 제27권4호
    • /
    • pp.213-222
    • /
    • 2014
  • 국내 배경지역인 제주도 고산측정소에서 2012~2013년에 대기 미세먼지를 채취하여 분석한 결과로부터 연무와 비현상일의 조성특성을 조사하였다. 연무 시 $nss-SO_4{^{2-}}$, $NO_3{^-}$, $NH_4{^+}$ 농도는 비현상일에 비해 조대입자에서 2.1~3.7배, 미세입자에서 3.1~6.5배로 미세입자에서 더 높게 증가하였고, 특히 $NO_3{^-}$ 농도가 미세입자에서 6.5배 상승하였다. 원소성분들 중에는 S, Zn, Pb, K 등이 비현상일보다 조대입자에서 3.0~5.6배, 미세입자에서 3.2~7.7배 증가하나 Al, Fe, Ca 등은 대부분 조대입자에서 농도가 크게 증가하는 경향을 보였다. 역궤적 분석 결과 연무 시 $nss-SO_4{^{2-}}$, $NO_3{^-}$ 농도는 중국으로부터 유입되었을 때 더 높은 농도를 나타내었고, 특히 기류가 중국남부를 통과했을 때 $NO_3{^-}$ 농도가 더 크게 상승하는 경향을 보였다. 또 $NO_3{^-}/nss-SO_4{^{2-}}$ 농도비는 중국에서 기류가 이동했을 때 조대입자에서 상대적으로 높은 비율을 보이나 미세입자에서는 오히려 한반도를 통과했을 때 더 높은 성분비를 나타내었다.

Accumulated organic matter, litterfall production, and decomposition tell us the status of litter dynamics in forests

  • Kim, Jae-Geun
    • Journal of Ecology and Environment
    • /
    • 제35권2호
    • /
    • pp.99-109
    • /
    • 2012
  • Litterfall dynamics in forests are assessed by estimating biomass production and decomposition. However, there have been few studies on how litter dynamics impact the health and management of ecosystems. Here, a new approach to measure and assess ecosystem function is presented based on conventional methods using littertraps, litterbags, and the mass on the forest floor. To assess the status of litter dynamics, the decay rate (k) was estimated from a litterbag experiment, and removal rates ($k_i$) were determined from mass balance on the forest floor at 21 sites on three mountains in South Korea. The $k_3$ (organic mass ratio of $O_i$ and $O_e+O_a$ + A horizons in November) values in an equilibrium state in South Korea were within the range of $k{\pm}0.174$ when considering the annual variation of litterfall production. This study also suggests that sampling sites for these types of studies should be in the middle, not at the ends, of steady slopes on the forest floor.

중년여성의 체중관리 실태와 성인병 위험도 (Weight Control and Cardiovascular Risk in Middle-Aged Women)

  • 김정아;정승교
    • 재활간호학회지
    • /
    • 제7권1호
    • /
    • pp.33-47
    • /
    • 2004
  • The purpose of this study was to investigate weight control practices and cardiovascular risk in middle-aged women. 304 middle-aged women were selected as subjects from thirties to fifthies living at J city in Chung-Buk Do. Data were collected using a questionnaire, anthropometric measurements, BP & total cholesterol level in serum from April 1, to June 30, 2003. The results of this study were as follows: The middle-aged woman's age is average $43.95{\pm}7.09yr$ and mean BMI(body mass index) was $23.54{\pm}3.09\;kg/m^2$. Underweight, normal weight, overweight, obese women were 3.0%, 39.5%, 27.9% and 29.6%respectively. Subjects perceived own as 'Slim' 5.9%, 'ordinary' 45.7%, 'Fat' 48.4%. Their weight perception coincide their own actual body weight but as many as 41.8% of overweight and 9.0% of obese perceived themselves as being 'ordinary'. Middle age women with past weight control experience were 55.6%, and only 35.5% was doing weight control at present. Of these subjects, 71.4% reported wanting to lose weight and the primary reason of weight control was to improve their appearance(39.53%). The most frequently reported weight control behavior was 'exercise' followed 'dieting', but 39.6% reported using 'diet food', 12.4% 'behavior modification', 12.4% 'fasting', and 'diet-drug'(3.6%) or 'smoking'(3.6%). Effective weight control methods were thought regular exercise(97.1%) & dieting (79.3%). And behavior modification(71.4%) or diet camp(60%) were effective, too. An average waist circumference was $79.80{\pm}9.47cm$, waist/hip ratio was $86.63{\pm}6.78$, waist/height ratio was $50.43{\pm}6.10$. In the index of abdominal obesity, 79.7 % of middle-aged women was waist/height ratio over 0.46, 65.3% was waist/hip ratio over 0.85, 28.4% was waist circumference over 85cm. There were significant differences in the degree of abdominal obesity according to age and BMI. In the index of cardiovascualr risk, 10.9% of middle aged women was systolic hypertension over 140mmHg, 18.7% was diastolic hypertension over 90mmHg and 10.6% was hypercholesterolemia over 200mg/dl. There was significant difference in systolic hypertension ratio according to age. There was significant difference in diastolic hypertension ratio according to age and obesity. There were significant differences in hypercholesterolemia accorting to obesity. The abdominal obesity indices and the levels of T-cholesterol in the serum, systolic and diastolic BP increased significantly according to age. T-cholesterol in serum was predicted 2.6% by waist/height ratio. And systolic BP was predicted 15.2% by waist/height, add BMI to 16.8%. Subject's diastolic BP was predicted 12.1% by BMI. Therefore waist/height ratio and BMI were significant factors for the predictors of cardiovascular risk. There was significant correlation between index of obesity and cardiovascular risk. T-cholesterol in serum had correlation with waist/eight ratio(r=0.174) and waist circumference(r=0.48). Systolic BP had correlation with waist/height ratio(r=0.387), and BMI(=0.371). diastolic BP correlation had correlation with BMI(r=0.343) and waist/height ratio(r=0.327). In conclusion, The prevalence of obesity was 29.6% in 304 cases, and increased as age after menopause increased. Middle-aged women's weight perception and actual BMI coincide but some of them did not. Trial to reduce weight was attempted. But most of them did not actually. Undesirable weight control method such as using drugs, fasting, smoking was used by some women. It is important to educate about health weight control methods and raise their awareness of exact body figures. High frequency of abdominal obesity in middle-aged women had correlation with hypertension and hypercholesterolemia. Abdominal index such as waist/height ratio, waist circumference, waist/hip ratio was used. Women's hypertension, hypercholesterolemia significantly related to body mass index and abdominal obesity.

  • PDF

사상체질에 따른 신체적, 심리적 특성의 연구 (A Study on the Physical and Psychological Characteristics in Sasang Constitutional Medicine)

  • 서은희;최애련;하진호;채한;김판준;구덕모
    • 사상체질의학회지
    • /
    • 제21권3호
    • /
    • pp.48-62
    • /
    • 2009
  • 1. Objectives: The purpose of this study was to analyze the physical and psychological characteristics of each Sasang type groups which were classified by Sasang medicine specialist. 2. Methods: The subjects were 115 (85.2% of male) university students with $26.8\pm5.4$ yrs. of age and $12.9\pm1.7$ yrs. of education. We can get 30 of Soyang type, 39 of Taeeum type, 46 of Soeum type after the Sasang type classification. Their physical characteristics were measured with Bioelectrical Impedance Analysis (Inbody 720, Biospace, Seoul), and psychological characteristics with Temperament and Character Inventory (Maumsarang, Seoul). The general linear model (SPSS 12.0, SPSS Inc, Chicago) were used for the analysis with gender and age as covariance. 3. Results and Conclusions: Taeeum type group ($75.64\pm13.01$, $26.12\pm4.16$, $15.74\pm2.42$, $11.30\pm1.80$, $3.93\pm0.62$, $18.43\pm7.70$) showed significantly bigger weight, intra-cellular water, extra-cellular water, protein, mineral, body fat mass than Soeum type group ($61.32\pm8.56$, $22.54\pm3.87$, $13.70\pm2.15$, $9.74\pm1.68$, $3.35\pm0.51$, $10.79\pm3.97$). In obesity degree such as Body Mass Index and Waist-hip ratio, and circumference measures in chest, waist and hip, we found significant differences in the order of Taeeum>Soyang>Soeum. As a psychological perspectives Soyang type group ($41.90\pm13.32$) has higher NS (Novelty-Seeking) score than Soeum type group ($35.22\pm11.22$) with marginal significance (p=0.052). In sub-scale measurements Soeum type group ($10.61\pm3.69$) has significantly lower value than other two groups in P3 (Ambition). The results of present study showed that Taeeum type by specialist has same physical characteristics as previously reported QSCC II based studies. Temperament profile of each Sasang type group will serve as an important evidence for further study showing that the Sasang typology has biological basis.

  • PDF