• Title/Summary/Keyword: Seasonal effects

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Effect of the Freshwater Discharge on Seawater and Sediment Environment in a Coastal Area in Goheung County, South Korea

  • Nguyen, Hoang Lam;Jang, Min-Seok;Cho, Hyeon-Seo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.3
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    • pp.270-276
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    • 2014
  • Seasonal characteristics of water and sediment qualities and potential effects of the freshwater discharge from a small tide embankment interior in a coastal area in Goheung county were investigated from May to September in 2012. Chemical oxygen demand values (COD) were mostly higher than 2 mg/L in summer ebb tide, which exceed the standard value of water quality criteria II of acceptable level for aquaculture activities. Nitrogen and phosphorus were found as the limiting nutrients for algae growth in summer and fall and in spring, respectively. Nitrogen was the limiting nutrient for diatom growth in the whole studied period. The sudden high values of COD, ammonia, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) were found in water sample collected from station 5 which located in front of the tide embankment sluice gate during spring ebb tide. The freshwater discharge form the tide embankment interior maybe affected the survey areas during a short time interval. Mean values of eutrophication index of the surveyed coastal region in spring, summer and fall were all bigger than 1. Water quality was mostly considered at level II which acceptable for aquaculture activities. Sediment quality in this study was generally in the range of standard for fisheries environment.

Effectiveness and safety of seasonal influenza vaccination in children with underlying respiratory diseases and allergy

  • Kang, Jin-Han
    • Clinical and Experimental Pediatrics
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    • v.57 no.4
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    • pp.164-170
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    • 2014
  • Influenza causes acute respiratory infections and various complications. Children in the high-risk group have higher complication and hospitalization rates than high-risk elderly individuals. Influenza prevention in children is important, as they can be a source infection spread in their communities. Influenza vaccination is strongly recommended for high-risk children with chronic underlying circulatory and respiratory disease, immature infants, and children receiving long-term immunosuppressant treatment or aspirin. However, vaccination rates in these children are low because of concerns regarding the exacerbation of underlying diseases and vaccine efficacy. To address these concerns, many clinical studies on children with underlying respiratory diseases have been conducted since the 1970s. Most of these reported no differences in immunogenicity or adverse reactions between healthy children and those with underlying respiratory diseases and no adverse effects of the influenza vaccine on the disease course. Further to these studies, the inactivated split-virus influenza vaccine is recommended for children with underlying respiratory disease, in many countries. However, the live-attenuated influenza vaccine (LAIV) is not recommended for children younger than 5 years with asthma or recurrent wheezing. Influenza vaccination is contraindicated in patients with severe allergies to egg, chicken, or feathers, because egg-cultivated influenza vaccines may contain ovalbumin. There has been no recent report of serious adverse events after influenza vaccination in children with egg allergy. However, many experts recommend the trivalent influenza vaccine for patients with severe egg allergy, with close observation for 30 minutes after vaccination. LAIV is still not recommended for patients with asthma or egg allergy.

High Performance of Temperature Gradient Chamber Newly Built for Studying Global Warming Effect on a Plant Population

  • Lee, Jae-Seok;Tetsuyuki Usami;Takehisa Oikawa;Lee, Ho-Joon
    • The Korean Journal of Ecology
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    • v.23 no.4
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    • pp.293-298
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    • 2000
  • To study the effect of global warming on the growth of plants and plant populations throughout their life cycle under a field-like condition, we constructed a Temperature Gradient Chamber (TGC) in Tsukuba, Japan. The chamber had slender shape : 30 m long. 3 m wide, and 2.5 m high. That satisfactory performance was confirmed by a test throughout all seasons in 1998: the projected global warming condition in the near future was simulated. That is, independent of a great daily or seasonal change in ambient meteorological conditions, air temperatures at the air outlet were warmed 5$^{\circ}C$ higher than those at the ambient (the annual mean was 14.3$^{\circ}C$) with precision of ${\pm}$0.2$^{\circ}C$ (the annual means were 19.2$^{\circ}C$) with a rising rate of approximately 1$^{\circ}C$ every 5 m. This chamber will enable us to study the effects of global warming on growth of plants and plant populations because their abilities to control air temperature are excellent. TGC is expected that it would be utilized for studying the effect of global warming on plant growth under natural weather conditions.

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Filling in Water Temperature Data of Aquatic Environments using a Pre-constructed Relationship

  • Lee, Khil-Ha
    • Journal of Environmental Science International
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    • v.26 no.10
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    • pp.1125-1133
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    • 2017
  • In this study a method for filling in missing data of river water temperature using a pre-constructed mathematical relationship between air and water temperatures is presented. A regression between water temperatures at individual stations and ambient air temperatures at nearby weather stations can provide a practical method for representing missing water temperature data for an entire region. Air and water temperature data that were collected from two test sites (one coastal and, one inland) were individually fitted to a nonlinear regression model. To consider seasonal hysteresis effects, separate functions were fitted to the data in the rising and falling limbs. A single-criterion, multi-parameter optimization technique was used to determine the optimal parameter sets. This method minimizes the differences between the time series of the measured and estimated data. The constructed air-water temperature relationship was subsequently applied to represent missing water temperature data. It was found that the RMSEs(MBEs) were in the range of $1.843-1.976^{\circ}C(-0.329-0.201^{\circ}C)$ and the coefficient of determination were in the range of 0.92-0.96. The results demonstrate that the predicted water temperatures using the regression equations were reasonably accurate.

Effect of Vertical Mixing Scheme on Upper Ocean Simulation of the East Sea (연직혼합모수화가 동해 상층 모사에 미치는 영향)

  • Jang, Chan-Joo;Lim, Se-Han
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.6
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    • pp.1034-1042
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    • 2010
  • This study investigates effects of three different parameterizations of vertical mixing scheme on upper ocean simulation of the East Sea, focusing on the seasonal variations of the sea surface temperature(SST) and the mixed layer depth(MLD) using an ocean general circulation model(GFDL MOM1.1). The considered vertical mixing schemes are the Laplacian scheme(L scheme) that use a constant eddy coefficient, the Mellor-Yamada scheme(MY scheme), and a new scheme(Noh scheme). The Noh scheme, a second-order turbulence closure, was developed considering recent observational evidences such as the enhancement of turbulent kinetic energy near the sea surface. During summer L scheme underestimates the SST, while MY scheme overestimates the SST, compared to climatological SST. Noh scheme produces the SST in better agreement with climatological one. During winter all schemes overestimate the SST up to $4^{\circ}C$ compared to climatological SST. Vertical profiles of the basin-mean temperature show that L scheme produces higher temperature below the thermocline than those of other schemes. The winter MLD simulated from L scheme is rather large compared to that from other schemes, but the differences in MLD during summer are not significant.

A Numerical Analysis on the Outside Pressure Distribution by Outdoor Wind Effect in a High-rise Residential Building (수치해석을 이용한 초고층 주거건물에서 외풍영향에 의한 외벽 압력 분포 분석)

  • Kim, Chi-Wan;Yang, Soon-Chang;Ahn, Young-Chull
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.10
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    • pp.639-645
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    • 2011
  • The object of this study is to analyze and evaluate outdoor wind pressure effect in a high-rise residential building when seasonal wind blow on coast area. The target building consists of 3 tower buildings over 250m in height. For the evaluation of the outdoor wind effect, CFD simulation was performed. The results of the simulations are as follows : 1) In that case of high-rise building, horizontal stream is more affected than vertical stream. 2) In case of summer season northeasterly wind, building pressure distributions are unstable and surface pressures of outside are effected respectively. 3) In case of winter season westerly wind, building preassure differentiations are not so much because of screening effects of the B, and the C buildings. 4) In case of winter season northwesterly wind, front wind affects on the A building directly because of no obstacles.

Diurnal Activity Patterns of Jeju Ponies (Equus caballus)

  • Rho, Jeong-R.;Choe, Jae-C
    • Animal cells and systems
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    • v.6 no.4
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    • pp.293-299
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    • 2002
  • We investigated seasonal variation of diurnal activity patterns in Jeiu ponies (Equus caballus). The data were collected from a semi-natural herd during daylight hours from March to September 1998. Over all months the mean proportion of time spent grazing was 83.7% ( $\pm$29.7 S.D.): that resting was 15.7$\pm$17%, grooming 0.7$\pm$1.2%, and moving 0.56$\pm$5.4%, Activity patterns varied with the seasons. The mean proportion of grazing mares peaked during late winter and early spring (March), when there was not enough food, and declined during other seasons (between May and September), when food was abundant. The mean proportion of mares that were resting and mutual grooming peaked in spring (April and May), at which time the weather was warm and food became abundant. During other seasons when grasses started to grow and the weather was mildly cool, these activities were less common. The mean proportion of mares that were moving peaked in June, although it was a small proportion of the total activity. For those mares without foals, resting periods were longer in older mares than in younger mares, but for the mares with foals this pattern was not evident. From these data, we hypothesize that the dominance hierarchy of the mares effects the diurnal activity pattern.

Seasonal Effects of Livestock Wastewater Treatment by a Constructed Wetland (인공습지에 의한 축산폐수의 처리시 계절적 영향)

  • Park, Jae-Hong;Kwon, Soo-Youl
    • Journal of Wetlands Research
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    • v.7 no.3
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    • pp.33-39
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    • 2005
  • Constructed wetlands are considered as an important tool for wastewater treatment, wastewater management and flooding control. In addition, one of the most promising technologies for application in many countries seems to be constructed wetlands due to their properties such as utilization of natural processes, simple construction, operation and maintenance, process stability, cost effectiveness, etc. This research is performed to find the possibility for treating livestock wastewater using a constructed wetland. The removal efficiencies of CODcr, TN, TP, SS, and color were 97.9%, 97.8%, 97.2%, 99.1%, and 84.9%, respectively. In particular, SS was completely removed. In conclusion, constructed wetlands could be applied to livestock wastewater treatment. Further, it needs time for stabilization to reduce the pollutants accumulated in soil.

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A Study on Air Temperature Difference between Windward and Leeward Side at High-rise Buildings (고층건물 풍상면과 풍하면의 기온차)

  • Jin, Ri;Cui, Hua;Yu, Jin-Hang;Ku, Hee-Yeong;Zheng, Hai-Yan;Jin, Wen-Cheng;Lee, Kyoo-Seock
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.1
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    • pp.63-71
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    • 2012
  • To investigate the air temperature difference between windward and leeward side at high-rise building area, the air temperature and relative humidity data were observed for 10 minute interval from July 9, 2011 to November 30, 2011. The observed data were compared, analyzed and examined to illustrate air temperature between windward side (H Apartment) and Leeward side (W Apartment). The diurnal and seasonal variation of air temperature difference between windward and leeward site were also investigated. After the analysis, the overheat of windward side by $0.4^{\circ}C$ irrespective short distance of two observation positions. It was also lower than those of surrounding air temperature observing stations. It is mainly due to the air temperature decreasing effects of leeward side of high rise buildings.

Changes in the Earth's Spin Rotation due to the Atmospheric Effects and Reduction in Glaciers

  • Na, Sung-Ho;Cho, Jungho;Kim, Tu-Hwan;Seo, Kiweon;Youm, Kookhyoun;Yoo, Sung-Moon;Choi, Byungkyu;Yoon, Hasu
    • Journal of Astronomy and Space Sciences
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    • v.33 no.4
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    • pp.295-304
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    • 2016
  • The atmosphere strongly affects the Earth's spin rotation in wide range of timescale from daily to annual. Its dominant role in the seasonal perturbations of both the pole position and spinning rate of the Earth is once again confirmed by a comparison of two recent data sets; i) the Earth orientation parameter and ii) the global atmospheric state. The atmospheric semi-diurnal tide has been known to be a source of the Earth's spin acceleration, and its magnitude is re-estimated by using an enhanced formulation and an up-dated empirical atmospheric S2 tide model. During the last twenty years, an unusual eastward drift of the Earth's pole has been observed. The change in the Earth's inertia tensor due to glacier mass redistribution is directly assessed, and the recent eastward movement of the pole is ascribed to this change. Furthermore, the associated changes in the length of day and UT1 are estimated.