• Title/Summary/Keyword: air-spring

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Atmospheric Aerosol Optical Properties in the Korean Peninsula

  • Oh, Sung-Nam;Sohn, Byung-Ju;Chung, Hyo-Sang;Park, Ki-Jun;Park, Sang-Soon;Hyun, Myung-Suk
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.423-423
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    • 2003
  • The radiative properties of atmospheric aerosol are determined by the mass and chemical characteristics, and optical properties such as aerosol optical depth (AOD), ngstr m parameter ( $\alpha$) and single scattering albedo (SSA). In particular these aerosol optical properties also determine surface temperature perturbation that may give some information in understanding the regional atmospheric radiative forcing. For understanding the radiative forcing and regional surce of aerosol, this paper summarizes and compares the aerosol optical properties results from and compares the atmospheric aerosol optical properties results from two different experiments: Anmyeon 2000 and Jeju 2001. Korea Global Atmosphere Watch Observatory (KGAWO) at Anmyeon island and ACE-Asia super-site at Gosan Jeju island have measured the radiations and aerosols since the year of 2000. The sites are located in the mid-west and south of Korea peninsula where it is strongly affected by the Asian dust coming from China region in every spring. Aerosol optical properties over both sites were measured through the ground-based sun and sky radiometers were analyzed for understanding the radiation and climate properties. Number concentration and chemical components of aerosol were additionally analyzed for the source estimation in the transportation. The frequency distributions of aerosol optical depth are rather narrow with a modal vaiue of 0.38 at both sites. However, the distributions of show one peak (1.13) at Jeju but two peaks (0.63 and 1.13) at Anmyeon. In the cases of Anmyeon, one peak around 0.63 corresponds to relatively dust-free cases, and the second peak around 1.13 characterizes the situation when Asian dust is presented. The correlation between AOD and resulted high correlation on the wide range with high values of optical depth at Anmyeon, otherwise a narrow range of with moderate to low AOD at Jeju. In dust free condition SSA decrease with waveleneth while in the presence of Asian dust SSA either stays neutral or increases slightly with wavelength. The change of surface temperature shows the stronger positive correlations with aerosol optical depth increase at Anmyeon than Jeju. In the chemical properties the aerosol are related to high concentrations in inorganic matters, SO$^4$, NO$_3$, CA2+ in fine and coarse.

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Method of Decreasing Cracking Index by Different Mix Conditions for Separated Placement and its Field Application (콘크리트 배합요인별 상·하부 분리타설에 의한 수화열 균열지수 저감방안 및 현장적용)

  • Kim, Min-Ho;Han, Cheon-Goo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.3
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    • pp.292-298
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    • 2016
  • In this research, considering the practical situation of separated placing method for mass concrete structure, an efficient method of controlling the heat of hydration is suggested by comparing between the simulated values and actual measurements conducted with the optimum mix design obtained from the various mix conditions with different types and amount of supplementary cementitious materials(SCMs). As the result of the research, firstly, the optimum mix designs for top and bottom layers were determined by Midas gen as OPC to FA of 85 to 15, and OPC to FA to BS of 50 to 20 to 30, respectively. The concrete mixtures prepared with the mix designs determined from the simulation satisfied the target performance range in slump, air content and compressive strength. Additionally, from temperature measurement for the actual mass concrete placed during spring, the maximum temperature difference between surface and core was about $10^{\circ}C$ with 59 and $49^{\circ}C$ for top and bottom layers, respectively, and 1.4 of cracking index was obtained. Therefore, considering the practical conditions of mass concrete construction, it is considered that the different heat of hydration method using different mix designs with SCMs can be an efficient method for controlling thermal cracking and settling cracking of mass concrete.

Correlation between a Soil Respiration and Environmental Factors, Air Temperature and Precipitation in Pinus densiflora Community in Namsan and Meaning on an Urban Forest Management (남산 소나무군락의 토양호흡과 환경요인인 기온과 강수량과의 상호관계 및 도시림 관리의 의미)

  • Lee, EungPill;Lee, SooIn;Park, JaeHoon;Kim, EuiJoo;Hong, YoungSik;Lee, SeungYeon;You, YoungHan
    • Journal of Korean Society of Forest Science
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    • v.109 no.2
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    • pp.136-144
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    • 2020
  • To prepare the management plan for reduction of the organic carbon emission caused by soil respirations, the amount of organic carbon emission from the pedosphere in Pinus densiflora community within metropolis park was quantified and then the correlations between quantified values and climate factors were analyzed. To this study, we investigated the amount of emitted organic carbon through soil respirations of Pinus densiflora community within Mt. Nam in Seoul-si, Korea, and identified correlationship with environmental factors. As a result, the average amount of organic carbons, included in soil respirations of P. densiflora community in Mt. Nam, was 7.978 ton C ha-1 yr-1. Also, precipitation of spring (March to May) was one of the environmental factors explaining the increase and decrease of soil respiration. This results suggest a drainage management to keep the low water content in understorey soils is important to an ecological management of metropolitan forests.

Studies on the Mulberry Variety Yongchonppong I. Physico-chemical Properties of Yongchonppong and Differencies of Leaf Value for Food in Growing Silkworm through Different Feeding Period. (용천뽕에 관한 연구 I. 용천뽕의 이화학성과 상잠기간 급여시기에 따른 사료가치의 차이)

  • 박광준;양성열
    • Journal of Sericultural and Entomological Science
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    • v.32 no.2
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    • pp.94-100
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    • 1990
  • Yongchonppon, one of the native varities, is the highest clod resistant. For its practical use, feeding test has been implemented in the ordinary rearing and in the branch rearing 1987 through 1988. The results are summarized as follows. 1. The feeding of Yongchonppong at the 4th and 5th instar made 5% decrease in spring and 10% decrease of cocoon yield in autumn, respectively, while cocoon shell ratio was a little less and percentage of raw silk was a little high, as compared to the feeding of Kaeryangppong. 2. The feeding of Yongchonppong at the 4th instar only showed nearly same nearing result as the feeding of Kaeryangppon. 3. In case of the feeding of yongchonppong at the 4th instar and early stage of the 5th instar, cocoon yield and percentage of raw silk marked 96% and 97-98% of Kaeryangppong. 4. The total nitrogen and crude protein of Yongchonnppong was less, while the total carbohydrate, crude ash and crude fat were high, as compared to those of Kaeryangppong. It had more phosphate and boric and less manganese than Kaeryangppong. 5. The leaf aereal weight of Yongchonppong was 1.57g/dcm2 and the leaf thickness was 113$\mu$. The moisture reducing rate marked 41.3% after three hour exposure to the air.

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Effect of Drying Temperature on High Quality Functional Processed Products of Chinese Matrimony Vine (가공용 소재로서 구기자나무 잎의 건조온도 조건)

  • Ju, Jung Il;Lee, Jeong;Paik, Seung Woo;Yun, Tug Sang;Park, Young Chun;Lee, Bo Hee;Kim, Hyun Ho;Lee, Hee Bong
    • Korean Journal of Medicinal Crop Science
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    • v.23 no.6
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    • pp.468-472
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    • 2015
  • Background : Chinese matrimony vine (Lycium chinense Mill.) is a deciduous shrub belonging to the Solanaceae. The leaves are used as an alternative raw material replacing dried fruits associated with high production costs in many industires. The aim of this experiment was to determine the effect of drying temperature on the leaves used in the manufacture of functional products. Methods and Results : The leaves of Chinese matrimony vine were harvested when the plant height reached 60 - 70 cm in the spring and treated at four different temperatures ($40^{\circ}C$, $50^{\circ}C$, $60^{\circ}C$ and $70^{\circ}C$). The time to reach the desiccation state of 20% was 63 h at $40^{\circ}C$, 37 h at $50^{\circ}C$, 17 h at $60^{\circ}C$ and 11 h at $70^{\circ}C$. The drying rate per hour was 1.28% at $40^{\circ}C$, 2.25% at $50^{\circ}C$, 4.94% at $60^{\circ}C$ and 7.60% at $70^{\circ}C$. No significant difference were observed in ash, crude fat, polyphenol or rutin content of treated samples. Crude protein and betaine content decreased with higher dry temperatures. Nitrogen free extract of the treated samples increased with higher drying temperatures. Conclusions : Taking into consideration drying time, drying rate, color value, energy consumption and functional ingredients is advantageous to dry the leaves of the Chinese matrimony vine at $60^{\circ}C$ using a hot air agricultural dryer.

Temperature and Salinity Distribution in Deukryang Bay in Summer of 1992-93 (1992-93년 하계 득량만의 수온과 염분의 분포)

  • KIM Sang-Woo;CHO Kyu-Dae;RHO Hong-Kil;LEE Jae Chul;KIM Sang-Hyun;SHIN Sang-Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.28 no.1
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    • pp.7-14
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    • 1995
  • As a part of the multidisciplinary oceanographic study for the productivity enhancement in Deukryang Bay, temperature and salinity were observed from 1992 through 1993. From the results, only the data in summer of two years are compared. Owing to the contrary meteorolgical conditions in both summers both of temperature and salinity had the patterns of horizontal distributions quite different from each other. In 1992 with low precipitation, there was a tendency of temperature increase and salinity decrease from the bay mouth towards the bay head. In 1993 when the air temperature was abnormally low, isotherms and isotherms tended to be parallel to the local u3s of the bay where the warmer and less saline water distributed along the western coast. Reduced solar radiation and increase in the relative importance of the distribution of properties along the current that was parallel to the axis of the bay could be responsible for this result. Vertical structures of both temperature and salinity were dependent on the stirring effect of tidal current. Stratification was destroyed during the spring tide while it was formed during the neap tide.

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Comparison of Nitrogen Dioxide Retrieved by MAX-DOAS and OMI measurements in Seoul (지상원격측정 MAX-DOAS 시스템과 위성 OMI센서로 서울에서 산출된 이산화질소 층적분농도의 비교연구)

  • Lee, Hanlim
    • Korean Journal of Remote Sensing
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    • v.29 no.2
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    • pp.235-241
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    • 2013
  • $NO_2$ vertical column densities were retrieved via ground based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements for the first time for 6 months over the spring season in 2007 and 2008 in Seoul, one the megacities in the Northeast Asia. The retrieved $NO_2$ vertical column densities were compared with those obtained from space borneOzone Monitoring Instrument (OMI). Over the entire measurement period, the $NO_2$ vertical column densities measured by MAX-DOAS ranged from $1.0{\times}10^{15}molec{\cdot}cm^{-2}$ to $6.0{\times}10^{16}molec{\cdot}cm^{-2}$ while those obtained by OMI ranged $1.0{\times}10^{15}molec{\cdot}cm^{-2}$ to $7.0{\times}10^{16}molec{\cdot}cm^{-2}$. The correlation coefficient between $NO_2$ vertical column densities obtained from MAX-DOAS and OMI is 0.73 for the entire measurement period whereas the correlation coefficient of 0.85 is found for the dates under the clear sky condition. The cloudy condition is thought to play a major role in increase in uncertainty of the retrieved OMI $NO_2$ vertical column densities since air mass factor may induce high uncertainty due to the lack of cloud and aerosol vertical distribution information.

Qualitative Research on Wearing Conditions and Health-Related Wearing Perception of Older Women (고령 여성의 착의 실태와 건강 관련 착의 인식에 대한 질적 연구)

  • Shim, Huen Sup;Lee, Yun Jung;Kweon, Soo Ae;Chung, Hae Won;Yoo, Shin Jung;Park, Joonhee;Park, Joo Hee;Jeong, Woon Seon
    • The Korean Journal of Community Living Science
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    • v.28 no.1
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    • pp.17-28
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    • 2017
  • The purpose of this qualitative research was to examine the behavior patterns and activities related to the clothing of older women. A total of 31 older women were interviewed regarding indoor/outdoor wearing conditions, thermal sensation indoors, and their clothing perception related to health. The final outcomes were as follows. Firstly, interviewees viewed indoor temperature as neutral in the spring and fall. Many people felt cool or warm in the summer and warm or cold in the winter. Secondly, they controlled indoor temperature with an air conditioner and/or fan and by opening the window and/or wearing less clothing. In winter, most respondents used a heating system and wore more clothing. It seemed that the level of dependence on clothing was higher in winter. Thirdly, the number of garment layer indoors was similar among the four seasons, and many wore underwear. However, there were individual variations. Fourthly, interviewees tended to perceive clothing in relation to health. Textile materials appropriate to the season were firstly viewed as related to health, followed by climate adaptability, clothing pressure, UV protection, and aesthetic satisfaction. Fifthly, respondents showed positive attitudes towards health improvement by clothing even though they lacked information on it. From this research, older women showed positive the perception and attitudes regarding clothing from a health perspective. Since they lacked information, education is needed regarding the bases and ways to improve health through clothing behavior.

Forecasting of Daily Minimum Temperature during Pear Blooming Season in Naju Area using a Topoclimate-based Spatial Interpolation Model (공간기후모형을 이용한 나주지역 배 개화기 일 최저기온 예보)

  • Han, J.H.;Lee, B.L.;Cho, K.S.;Choi, J.J.;Choi, J.H.;Jang, H.I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.3
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    • pp.209-215
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    • 2007
  • To improve the accuracy of frost warning system for pear orchard in a complex terrain in Naju area, the daily minimum temperature forecasted by Korea Meteorological Administration (KMA) was interpolated using a regional climate model based on topoclimatic estimation and optimum scale interpolation from 2004 to 2005. Based on the validation experiments done for three pear orchards in the spring of 2004, the results showed a good agreement between the observed and predicted values, resulting in improved predictability compared to the forecast from Korea Meteorological Administration. The differences between the observed and the predicted temperatures were $-2.1{\sim}2.7^{\circ}C$ (on average $-0.4^{\circ}C$) in the valley, $-1.6{\sim}2.7^{\circ}C$ (on average $-0.4^{\circ}C$) in the riverside and $-1.1{\sim}3.5^{\circ}C$ (on average $0.6^{\circ}C$) in the hills. Notably, the errors have been reduced significantly for the valley and riverside areas that are more affected by the cold air drainage and more susceptible to frost damage than hills.

Survey of Airborne Fungi Levels in 24 Seasonal Divisions and Correlation Analysis with Meteorological Elements (24절기 야외 부유곰팡이 농도 조사 및 기상요소와의 상관성 분석)

  • Kim, Myoung Nam;Hong, Jin Young;Lee, Jeong Min;Park, Ji Hee
    • Journal of Conservation Science
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    • v.35 no.6
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    • pp.652-663
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    • 2019
  • To identify daily and annual changes in outdoor airborne fungi, it is necessary to shorten the collection cycle and increase the number of measurements. In this study, measurements were performed by employing an air sampler and potato dextrose agar media on the rooftop of National Research Institute of Cultural Heritage during a period of one year (August 2018 to July 2019). The collection cycle spanned the twenty-four seasonal divisions and the collection time was 2 p.m. and 11 p.m.. Meteorological elements were collected at intervals of one hour. Furthermore, the concentration of airborne fungi was monitored and correlation analysis with meteorological elements was subsequently conducted. Obtained results indicate that the concentration of airborne fungi is found to be highest in November, autumn, night, followed by autumn, summer, winter, and spring. The concentration, type, and dominant species of airborne fungi can vary depending on factors such as rainfall, typhoons, and yellow dust (fine dust). The concentration of airborne fungi indicates a strong positive linear relationship between precipitation, number of precipitation days, and relative humidity. The concentration of airborne fungi was related to the period of increase of dead plants in terms of nutrition source, and to the high relative humidity conditions including rainfall in terms of meteorological elements.