• Title/Summary/Keyword: Seasonal effects

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Tuberculous Cervical Lymphadenitis (경부 결핵성 임파선염)

  • Kim Joong-Kyu;Lee Choong-Han
    • Korean Journal of Head & Neck Oncology
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    • v.11 no.1
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    • pp.3-8
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    • 1995
  • Tuberculous cervical lymphadenitis is one of common cause of neck mass in young adult in Korea. Tuberculous cervical lymphadenitis known as scrofula was being treated by the 'Royal Touch' in the 5th century and by surgery in the 17th century, yet the principle of the treatment is still controversal. We report the clinical evaluation and therapeutic result about 121 tuberculous cervical lymphadenitis. The result were as follows: 1) The annual incidence(1985-1994) was 30.5 % (37 cases: 1985-1986), 17.7 % (21 cases: 1990-1992). 19.8%(24 cases: 1994). 2) The age of highest incidence was 20-29 year old age group in 41.3% (50 cases) and female predominated over male by 1.8 : 1. 3) The duration of disease was less than 6 months, in 85.9% (104 cases). 4) The most commonly involved LN group was superficial cervical group in 69.4% (84 cases), and difference between Rt & Lt, was not significant. 5) The most common symptom and local finding(P/E) were, painless swelling of LN in 74.3 % (90 cases) and single mass in 59.5 % (72 cases). 6) In seasonal variation, 85.9% (104 cases) was spring and summer. 7) Procedures except biopsy for evaluation were chest PA, AFB smear & culture(sputum), Mantoux test, USG, CT and, Associated extracervical tuberculous lesions were lung, axilla, breast. 8) In operation method (involving biopsy), Excision was 68.5 % (83 cases), neck dissection was 6.6% (8 cases). 9) The Modality, Duration and side effect of antituberculous medication: INH-Rifampin­Ethambutol was 66.1 % (88 cases), duration was 1 year in 84.3% (102 cases), side effects were severe GI trouble (24.8%), liver function damage (3.3%). 10) 3 cases recurred on the same site after 2 yrs(2 cases) and 4 months(1 case) and its treatment was curretage or I & D, with antituberculous medication.

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A Study for Joint Freezing in Concrete Pavement (콘크리트포장의 줄눈의 잠김에 대한 연구)

  • Lee, Seung-Woo
    • International Journal of Highway Engineering
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    • v.3 no.1 s.7
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    • pp.165-176
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    • 2001
  • Joints in jointed concrete Pavement are designed to control against randomly occurred cracks within slabs, which may be caused by temperature or moisture variation. The advantage of these artificial cracks (joints) over naturally occurred cracks are easy access of protections, such as installation of joint seal and load transfer mechanism. The potential benefits of joint seals are to prevent infiltration of surface water through the joint into underlying soil and intrusion of incompressible materials (debris, fine size aggregate) in to the joint, which may prevent weakening of underlying soils and spallings due to excessive compressive stress, respectively. For the adequate design of joint seal, horizontal variation of joint widths (horizontal joint movements) are essential inputs. Based on long-term in-situ joint movement data of sixteen jointed concrete pavement sections in Long Term Performance Pavement Seasonal Monitoring Program (LTPP SMP), it was indicated that considerable Portion of joints showed no horizontal movements with change in temperature. This Phenomenon is called 'Joint Freezing'. Possible cause for joint freezing is that designed penetrated cracks do not occur at a joint. In this study, a model for the prediction of the ratio of freezing joints in a particular pavement sections is proposed. In addition, possible effects of joint freezing against pavement performance are addressed.

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A Time-Series Study of Ambient Air Pollution in Relation to Daily Mortality in Incheon, 1998-2001 (인천시 대기오염과 일별 사망의 상관성에 관한 시계열적 연구 (1998년${\sim}$2001년))

  • Cho, Yong-Sung;Lee, Jong-Tae;Kim, Yoon-Shin;Hyun, Youn-Joo;Moon, Jeong-Suk
    • Journal of environmental and Sanitary engineering
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    • v.18 no.3 s.49
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    • pp.89-99
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    • 2003
  • This study is peformed to examine the relationship between air pollution exposure and mortality in Incheon for the years of 1998 - 2001. Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of seasonal trend, air temperature, humidity, and day of the week as confounders in a nonparametric approach. Daily death counts were associated with CO(1 day before), O$_3$(2 day before), PM$_{10}$(1 day before), NO$_2$(1day before), SO$_2$(1 day before). Increase of 32.21 ${\mu}$g/m$^3$(interquartile range) in PM$_{10}$ was associated with 1.9 % (95% CI = 0.8 % - 2.9 %) increase in the daily number of death. This effect was greater in children(less than 15 aged) and elderly(more than 65 aged). We concluded that Incheon had 2 - 4 % increase in mortality in association with IQR in air pollutants. Daily variations in air pollution within the range currently occurring in Incheon might have an adverse effect on daily mortality. These findings also support the hypothesis that air pollution, at levels below the current ambient air quality standards of Korea, is harmful to sensitive subjects, such as children or elderly.

Characterization of Air Quality in Various Types of Indoor Environments in Urban Areas - Focusing on Homes, Offices, and Restaurants - (도시지역 실내환경 유형별 공기질 특성 평가 -가정, 사무실 및 식당을 중심으로-)

  • 백성옥;김윤신
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.4
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    • pp.343-360
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    • 1998
  • In this study, comprehensive air quality monitoring was undertaken with a variety of objectives to collect data on the levels of various indoor and ambient air quality parameters in the urban areas of Seoul and Taegu. The sampling sites were comprised of six offices, six residences and six restaurants in each city. The ambient air adjacent to the indoor sites was also simultaneously sampled for the same constituents. The sampling was conducted in two phases: summer of 1994 and winter of 1994/95. A range of air quality parameters were measured simultaneously, which include RSP, CO, COB, NOB, a range of VOC, airborne microbials, temperature, and relative humidity. The indoor and ambient levels of the pollutants measured in this study varied widely between the three types of environments studied. Comparison of median values for the three groups revealed that restaurants had higher indoor levels of most pollutants than homes or offices. There was also a clear pattern of the indoor levels of target pollutants being higher than those outdoors, particularly in restaurants. Concentrations of CO and most of the VOC were found to be significantly higher in the commercial districts, indicating the influence of vehicle exhaust emissions. A very wide range of VOC levels was documented in this study. Although median indoorloutdoor ratios indicated a generally increasing level of VOC indoors when compared to those outdoors, no statistically significant differences were found between indoor and outdoor VOC levels in homes and offices, implying the importance of ambient air quality in determining the quality of indoor air for homes and offices in urban areas. In addition, there was a general pattern of increasing concentrations from summer to winter, and similarly from outdoor to indoor air for nearly all target compounds. The seasonal differences in median levels were very clearly seen for fuel combustion related pollutants such as RSP, CO and VOC, this being attributed to the effects of increased fuel consumption during the cold season and to meteorological factors.

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Characteristics of and Affecting Factors on the Concentrations of Polycyclic Aromatic Hydrocarbons Associated with PM10in the Urban Atmosphere (도시 대기 중 PM10에 함유된 다환방향족탄화수소의 농도분포특성과 주요 영향인자)

  • 최진수;백성옥
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.1
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    • pp.33-44
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    • 2003
  • The atmospheric concentrations of particulate polycyclic aromatic hydrocarbons (PAHs) associated with PM$_{10}$ were determined in Taegu metropolitan area. Sampling was undertaken every five days throughout one year period from 1993 to 1994 at four sites, representing a residential, a commercial, an industrial, and a sub-urban area, respectively. Benzo (e) pyrene, benzo (k) fluoranthene, and chrysene were found to be the most abundant com-pounds during the study period. The concentrations of benzo (a) pyrene, one of carcinogenic PAHs, ranged 2.0~4.8 ng/㎥ in winter and 0.5~1.5 ng/㎥ in summer season, indicating a marked seasonal variation. It was found that there were very similar patterns in the relative profiles of PM$_{10}$-bound PAH concentrations among the four sampling sites, while the absolute levels of each PAH were significantly different from each site. In addition, the patterns of summer to winter concentration ratios for each PAH were almost identical between the different sites. Despite difficulties due to the lack of good markers for specific sources in the target compounds, we were able to evaluate and describe the effects of vehicle emissions and space heatings, using relative profiles of PAHs, winter to summer (W/S) ratios, PAH-to-PAH ratios, and the result of principal component analysis. As a con-sequence, it was concluded that the vehicle emissions in urban and sub -urban areas are likely to be a major contributor for PAH loadings in the ambient atmosphere during the non-heating season, while the contributions of residential heating and local industrial oil burning emissions were highly significant in heating season.son.

Characteristics of TSP Concentrations Measured at Gosan: Statistical Analysis (고산에서 측정한 TSP 농도 특성: 통계적 해석)

  • 박민하;김용표;강창희;김원형
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.1
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    • pp.93-100
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    • 2003
  • In this technical information, the long-term measurement data at Gosan between 1992 and 2001 are analyzed with various statistical methods. First. it was confirmed that the basic assumption of t-test is important to classify data correctly. Second, it was founded that the difference of the number of data per month can affect the averaged concentration. Third, by using a non-parametric statistical method long term trend of aerosol composition free from seasonal effects is obtained.

Sewage Treatment Using Natural Systems and Effluent Reuse for Crop Irrigation in Small Communities

  • Ham, Jong-Hwa;Yoon, Chun-G.;Jeon, Ji-Hong;Hwang, Ha-Sun
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.7
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    • pp.70-82
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    • 2003
  • A pilot study was performed from July 1998 to December 2002, including winter performance, to examine seasonal performance of a constructed wetland and subsequent pond system for treatment of sewage in small communities of Korea. Pond was operated as a intermittent-discharge pond during winter period, and continuous flow system during growing season; its effects was evaluated from December 2001 to April 2003. The subsurface flow (SSF) wetland was satisfactory for treating sewage with good removal efficiency even during the winter period. The wetland effluent concentrations of $BOD_5$ and TSS were often higher in winter than in the growing season, but this was explained by the higher loading rates, rather than lower removal efficiency. The relatively poor-quality wetland effluent was further polished during winter in the pond. The upper layer of the pond water column became remarkably clear immediately after ice melt. In the growing season, ponds could be operated as a continuous flow system to remove nutrients and pathogens, and the effluent of pond could be reused as a supplemental irrigation water without risk of infection by sewage-borne pathogens as well as causing adverse effect on growth and yield. Overall, the wetland system was found to be adequate for treating sewage with stable removal efficiency, and the intermittent-discharge pond was found to be effective for further polishing if necessary. Therefore, the combination of a wetland and subsequent pond system and reuse of effluent as crop irrigation water is recommended as a practical alternative to treat sewage in Korean small communities, and partial discharge of pond water in March is suggested.

A Study on the Curing of Concrete in field (콘크리트의 현장양생효과에 관한 연구)

  • 윤충섭;조병진
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.26 no.3
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    • pp.46-58
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    • 1984
  • This study was carried out to investigate the compressive strength and the other effects varying to seasons and curing days on the wet curing conditions of the plain concrete. The results obtained are summarized as follows; 1. The longer the wet curing days and the higher the temperature, the greater the compressive strength was expected. 2.。$_2$8, compressive strength of concrete at 28 days under the dry curing conditions showed a range in 64-76% of that under the wet curing conditions. 3. The seasonal variations in the compressive strength under the wet curing showed in order of summer>spring=autumn>winter, and that under the dry curing were in order of spring ≒autumn> summer> winter. 4. In order to obtain 90% of the design compressive strength, 7 days in spring or autumn and 2 weeks of the wet curing in summer were required. 5. The compressive strength of concrete under the wet curing by using wet straw bag cover was almost the same as that of water curing method. 6. Under the wet curing conditions, the higher the temperature, the greater the effect of the curing of concrete was obtained, however, the compressive strength of concrete was decreased under relatively higher (over 15$^{\circ}$ C) and lower temperature (below 4$^{\circ}$C). 7. Freezing damage was occured when temperature was below 0$^{\circ}$ C and humidity was relatively high. 8. A considerable differnce between estimation of $^{\circ}$$_2$8 from $^{\circ}$7 and measured one was appeared in case of the dry curing conditions. Oregon formula was appeared to be acceptable under the wet curing conditions. 9. In relationship between $^{\circ}$$_2$8 and $^{\circ}$7~, $^{\circ}$28=1. 52 $^{\circ}$7 under the wet curing conditions except winter season, and $^{\circ}$$_2$8 =(1.39-1, 48)$^{\circ}$7 under the dry curing conditions were shown.

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Effects of Nutrient Property Changes on Summer Phytoplankton Community Structure of Jangmok Bay (장목만에서 여름철 영양염 특성 변화가 식물플랑크톤 군집구조에 미치는 영향)

  • Jang, Pung-Guk;Jang, Min-Chul;Lee, Woo-Jin;Shin, Kyoung-Soon
    • Ocean and Polar Research
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    • v.32 no.2
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    • pp.97-111
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    • 2010
  • Phytoplankton production is affected by various physico-chemical factors of environment. However, one of the most critical factors generally accepted as controlling primary production of phytoplankton is nutrients. It has recently been found that the succession of phytoplankton groups and species are closely related to the chemical properties of ambient water including nutrient limitation and their ratios. In Jangmok Bay, silicate and nitrate are primarily supplied by rainfall, while phosphate and ammonia are supplied by wind stress. Typhoons are associated with rainfall and strong wind stress, and when typhoons pass through the South Sea, such events may induce phytoplankton blooms. When nutrients were supplied by heavy rainfalls during the rainy season and by summer typhoons in Jangmok Bay, the dominant taxa among the phytoplankton groups were found to change successively with time. The dominant taxon was changed from diatoms to flagellates immediately after the episodic seasonal events, but returned to diatoms within 3~10 days. Pseudo-nitzschia spp. were dominant mainly in the presence of low phosphate levels during the first of the survey which included the rainy season, while Skeletonema costatum was dominant when phosphate concentrations were high due to the strong wind stress during the latter half of the survey as a result of the typhoon. The competition between S. costatum and Chaetoceros spp. appeared to be regulated by the silicate concentration. S. costatum preferred high silicate and phosphate concentrations; however, Chaetoceros spp. were able to endure low silicate concentrations. These results implied that, in coastal ecosystems, the input patterns of each nutrient supplied by rainfall and/or wind stress appeared to contribute to the summer succession of phytoplankton groups and species.

Seasonal and Spatial Variations of Nutrient Fluxes in the Intertidal Flat of Keunso Bay, the Yellow Sea (서해 근소만 갯벌에서 영양염 플럭스의 계절 변화)

  • Kim, Kyung-Hee;Kim, Dong-Seon
    • Ocean and Polar Research
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    • v.30 no.3
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    • pp.225-238
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    • 2008
  • In order to investigate the effects of intertidal sediments on the nutrient cycle in coastal environments, the benthic fluxes of ammonium, nitrate, nitrite, phosphate, and silicate at two stations on the intertidal flat of Keunso Bay were determined during each season. The efflux of ammonium was observed at S1 and resulted from the diffusion of remineralized ammonium and acceleration caused by the bioirrigation of macrofauna. The influx of ammonium at S2 was probably due to nitrification in the water column. The influx of nitrate was observed at both stations during all seasons, indicating that the nitrate in the pore water was removed by denitrification. Vigorous bioirrigation led to the efflux of dissolved inorganic nitrogen (DIN) at S1, whereas the influx of DIN at S2 was predominantly caused by denitrification. Contrary to the diffusive and bio-irrigated release of remineralized phosphate from the sediment at S1, the influx of phosphate was observed at S2, which may be attributable to adsorption onto iron oxides in the aerobic sediment layer. Silicate, which is produced by the dissolution of siliceous material, was mostly released from the sediment by molecular diffusion and bioirrigation. However, the influx of silicate was observed at S2 during spring and winter, which was ascribed to adsorption by particulate matter or assimilation by benthic microphytes. The annual fluxes of DIN were 328 mmol $m^{-2}yr^{-1}$ at S1 and -435 mmol $m^{-2}yr^{-1}$ at S2. The annual fluxes of phosphate were negative at both sites (-2.8 mmol $m^{-2}yr^{-1}$ at S1 and -28.9 mmol $m^{-2}yr^{-1}$ at S2), whereas the annual fluxes of silicate were positive at both sites (843 mmol $m^{-2}yr^{-1}$ at S1 and 243 mmol $m^{-2}yr^{-1}$ at S2).