• Title/Summary/Keyword: Soil temperature change

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Temperature Dependence of PCBs in Urban Area of Seoul City (서울 대기 중 PCBs의 온도 의존성)

  • 여현구;최민규;천만영;김태욱;선우영
    • Journal of Korean Society for Atmospheric Environment
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    • v.18 no.3
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    • pp.193-204
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    • 2002
  • To investigate the relationships between the atmospheric concentrations of PCBs and temperature, quantity of both parameters was performed at an urban site in Korea from July 1999 to January 2000. The strength of correlations between total PCB and temperature was found to be significant (r = 0.752, p < 0.001). It hence indicates that total PCB contents were affected sensitively by temperature change during the sampling period. The ratio of PCB homologs and Deca-CB(PCB 209) also behaved quite similarly to the change of temperature (r>0.60, p<0.05). This may be inferable with the progress of the gas/particle partitioning to the gas phase, especially for fri-and tetra-CBs. Because they have high vapor pressure, they generally exist in the gas phase. The Clausius-Clapeyron equation was applied to the atmospheric PCB data, relating PCB partial vapor pressure to inverse temperature. This may essentially represent the temperature-controlled transition between condensed phase and atmospheric gas phase. The slopes of the resulting plot with International Council for the Explanation of the Seas (ICES) congener ranged from -2810 to -5887, with significantly steep slope and $R^2$(p< 0.005) It was inferred that the PCB atmospheric concentration was also affected by change in the surrounding conditions such as soil, lakes and trees.

Implementation of Complex Growth-environment Control System in Greenhouse (온실 복합생장환경 관제 시스템 구현)

  • Cho, Hyun Wook;Cho, Jong Sik;Park, In Gon;Seo, Beom Seok;Kim, Chan Woo;Shin, Chang Sun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.1
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    • pp.1-9
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    • 2011
  • In this paper, Wireless sensor network technology applied to various greenhouse agro-industry items such as horticulture and local specialty etc., we was constructed automatic control system for optimum growth environment by measuring growth status and environmental change. existing monitoring systems of greenhouse gather information about growth environment depends on the temperature. but in this system, Can be efficient collection and control of information to construct wireless sensor network by growth measurement sensor and environment monitoring sensor inside of the greenhouse. The system is consists of sensor manager for information processing, an environment database that stores information collected from sensors, the GUI of show the greenhouse status, it gather soil and environment information to soil and environment(including weather) sensors, growth measurement sensor. In addition to support that soil information service shows the temperature, moisture, EC, ph of soil to user through the interaction of obtained data and Complex Growth Environment information service for quality and productivity can prevention and response by growth disease or disaster of greenhouse agro-industry items how temperature, humidity, illumination acquiring informationin greenhouse(strawberry, ginseng). To verify the executability of the system, constructing the complex growth environment measurement system using wireless sensor network in greenhouse and we confirmed that it is can provide our optimized growth environment information.

Color Change in and Soil Removal from Cocoa Soiled Cloth in Hard Water

  • Kim, Hyo-Jeong;Seok, Hye-Joon;Chung, Hae-Won
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2009.03a
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    • pp.81-82
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    • 2009
  • IEC 60456 declared the cocoa soiled cloth to be one of the standard soiled test cloths for measuring the performance of the clothes washing machines. Researchers for textile washing have known that cocoa soiled cloth has shown unpredictable washing performance. The color of cocoa mainly comes from flavonoids, and flavonoids reversibly change color with alkalinity from pH 1 to pH 7 as food colorants. The color change of flavonoids under various washing conditions, in the alkali solution, has not yet been confirmed. In this study, we have investigated the color change and the soil removal of the cocoa soiled cloth which were washed with alkaline washing liquids of various hardnesses. The cocoa soiled cloth which was washed in the water which was 60ppm or higher became darker than the soiled cloth. When the cloth was washed in the detergent solution, the cloth was slightly darker only when the washing condition was $20^{\circ}$ and 250ppm. As the water hardness increased, the soil removal decreased and the higher washing temperature was more effective.

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Studies on the fluctuation of aerobic free-living nitrogen fixation bacteria in soil beneath the plant covers (식피별 비공생성 호기성 질소고정세균의 변동에 관하여)

  • 이태우;심재국
    • Korean Journal of Microbiology
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    • v.21 no.2
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    • pp.71-78
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    • 1983
  • The number of aerobic free-living nitrogen fixation bacteria and factors in soil at different stands covered with Pinus rigida, Quercus acutissima and Zoysia japonica in Cheongju area were investigated from Feb. to Sept 1981. 1. The numbers of $N_2-fixation$ bacteria, according to the seasonal changes, increased gradually from winter to spring and summer. But the growth pattern revealed some differences in accordance with plant cover stands : the numbers increased abruptly in May at Pinus, May-June at Quercus and Apr. May at Zoysia stand. The pick of numbers represented in Aug. Sept, at Pinus, Jul-Aug. at Quercus and May-Jun. at Zoysia stand, respectively. 2. The interrelationship between the monthly changes of enviotnmental factors and numbers of $N_2-fixation$ bacteria at different stands, mainly depends upon the soil temperature than other soil factors (r=0.71-0.84). The numbers of $N_2-fixation$ bacteria may increase 5-7 times according to increase $10^{\circ}C$ of soil temperature, and optimal range was $20{\sim}30^{\circ}C$ for growth. Equation of the interrelation between soil temperature and numbers could be stated as follows : log y=ax+b. 3. In the case of high soil temperature, the bacterial numbers presented high level in drought periods. Therefore, the $N_2-fixation$ bacterial species in these soil seem to consist of resistant to desication. 4. The influence of soil organic matter for growth of $N_2-fixation$ bacteria indicated low conrelation. The reason may seen the content of organic matter in these soil existed abundantly above the quantities of limitation for growth. 5. In artifical gradients, the $N_2-fixation$ bacteria were predominated at $20{\sim}30^{\circ}C$ same as natural condition, pH7-8, and 20-30% of soil water contents. 6. The vertical distribution of bacteria marked decreasing trends from surface to lower layers, and the decreasing degree was shown well in Zoysia, Quercus and Pinus stand in order. But in the trees, the numbers increased at 30cm layer estimated the region of root than 20cm layer. 7. Both catalase megative and positive group of $N_2-fixation$ bacteria in soil increased according to the rise of the soil temperature. Catalase positive group was revealed as dominant group in winter, and catalase negative group revealed in summer. The change of dominant pattern was shown during Feb. to Apr.

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Influence Factor on Remediation of PAHs-Contaminated Soil by Using Flowing Subcritical Water (흐름식 아임계수를 이용한 PAHs 오염토양 정화 영향인자)

  • Jo, Young-Tae;Islam, Mohammad Nazrul;Park, Jeong-Hun
    • Journal of Soil and Groundwater Environment
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    • v.18 no.4
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    • pp.1-7
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    • 2013
  • Subcritical water which acts as organic solvent with increasing temperature and pressure because dielectric constant and viscosity decrease can be used to remediate PAHs-contaminated soil. Factors influencing on extraction were studied with varying the water temperature $200{\sim}275^{\circ}C$, extraction time 0~90 min, flow rate 10~100 mL/min and pressure 3.9~10MPa. 300 g of soil sample which was contaminated with PAHs(naphthalene, phenanthrene, fluoranthene and pyrene; 423, 420, 539 and 428 mg/kg of initial concentration) was packed into the cell and placed to reactor and then the subcritical water was pumped through the cell for PAHs extraction. Naphthalene was removed almost 100% at relatively low temperature ($200^{\circ}C$). The removal rate of phenanthrene, fluoranthene, and pyrene increased by 8, 26, and 23% when the temperature increased from 200 to $275^{\circ}C$; and it was gradually increased as extraction time increased from 0 to 90 min. Decreasing removal rate when water flow rate increased from 10 to 30 mL/min, but there was no significant change after 30 mL/min. This is supposed due to channeling phenomenon. The pressure was not an effective factor for extraction of PAHs in this study. Based on the results, the importance of effective factor was in following sequence: temperature >> time > flow rate.

An Fundamental Study of on Freezing Characteristics of Antarctic Soil (남극 대륙기지 건설지에서 채취한 흙시료의 동결특성에 관한 기초연구)

  • Hong, Seung-Seo;Kim, Young-Seok;Bae, Gyu-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.1030-1038
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    • 2010
  • In order to design and construction of the Antarctic Continental Station at the Terra Nova Bay in the East Antarctic, ground characteristics for soil samples taken from the Antarctic. A series of laboratory tests were performed to investigate the variations of the thermal conductivity, the unfrozen water content according to the temperature change of the soil taken from the Antarctic. The temperature were low down below zero.

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Monitoring soil respiration using an automatic operating chamber in a Gwangneung temperate deciduous forest

  • Lee, Jae-Seok
    • Journal of Ecology and Environment
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    • v.34 no.4
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    • pp.411-423
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    • 2011
  • This study was conducted to quantify soil $CO_2$ efflux using the continuous measurement method and to examine the applicability of an automatic continuous measurement system in a Korean deciduous broad-leaved forest. Soil respiration rate (Rs) was assessed through continuous measurements during the 2004-2005 full growing seasons using an automatic opening/closing chamber system in sections of a Gwangneung temperate deciduous forest, Korea. The study site was an old-growth natural mixed deciduous forest approximately 80 years old. For each full growth season, the annual Rs, which had a gap that was filled with data using an exponential function derived from soil temperature (Ts) at 5-cm depth, and Rs values collected in each season were 2,738.1 g $CO_2$ $m^{-2}y^{-1}$ in 2004 and 3,355.1 g $CO_2$ $m^{-2}y^{-1}$ in 2005. However, the diurnal variation in Rs showed stronger correlations with Ts (r = 0.91, P < 0.001 in 2004, r = 0.87, P < 0.001 in 2005) and air temperature (Ta) (r = 0.84, P < 0.001 in 2004, r = 0.79, P < 0.001 in 2005) than with deep Ts during the spring season. However, the temperature functions derived from the Ts at various depths of 0, -2, -5, -10, and -20 cm revealed that the correlation coefficient decreased with increasing soil depth in the spring season, whereas it increased in the summer. Rs showed a weak correlation with precipitation (r = 0.25, P < 0.01) and soil water content (r = 0.28, P < 0.05). Additionally, the diurnal change in Rs revealed a higher correlation with Ta than that of Ts. The $Q_{10}$ values from spring to winter were calculated from each season's dataset and were 3.2, 1.5, 7.4, and 2.7 in 2004 and 6.0, 3.1, 3.0, and 2.6 in 2005; thus, showing high fluctuation within each season. The applicability of an automatic continuous system was demonstrated for collecting a high resolution soil $CO_2$ efflux dataset under various environmental conditions.

Assessing Climate Change Impact on Hydrological Components of Yongdam Dam Watershed Using RCP Emission Scenarios and SWAT Model (RCP 배출 시나리오와 SWAT 모형을 이용한 기후변화가 용담댐 유역의 수문요소에 미치는 영향 평가)

  • Park, Jong-Yoom;Jung, Hyuk;Jang, Cheol-Hee;Kim, Seong Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.3
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    • pp.19-29
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    • 2014
  • This study was to evaluate the potential climate change impact on watershed hydrological components of evapotranspiration, surface runoff, lateral flow, return flow, and streamflow using Soil and Water Assessment Tool (SWAT). For Yongdam dam watershed (930 $km^2$), the SWAT model was calibrated for five years (2002-2006) and validated for three years (2004-2006) using daily streamflow data at three locations and daily soil moisture data at five locations. The Nash-Sutcliffe model efficiency (NSE) and coefficient of determination ($R^2$) were 0.43-0.67 and 0.48-0.70 for streamflow, and 0.16-0.65 and 0.27-0.76 for soil moisture, respectively. For future evaluation, the HadGEM3-RA climate data by Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios were adopted. The biased future data were corrected using 30 years (1982-2011, baseline period) of ground weather data. The HadGEM3-RA 2080s (2060-2099) temperature and precipitation showed increase of $+4.7^{\circ}C$ and +22.5 %, respectively based on the baseline data. The impacts of future climate change on the evapotranspiration, surface runoff, baseflow, and streamflow showed changes of +11.8 %, +36.8 %, +20.5 %, and +29.2 %, respectively. Overall, the future hydrologic results by RCP emission scenarios showed increase patterns due to the overall increase of future temperature and precipitation.

Cleaning Method for Selective Removal of Stains from Historic Textiles and Stains Change by Long Period Storage -Focused on Blood Soil- (복식유물 오구의 선택적 제거를 위한 세척방법 및 장기간 보관에 따른 오구 변화 -혈액오구를 중심으로-)

  • Roh, Eui Kyung;Ryu, Hyo-Seon;Chae, Jeongmin
    • Journal of the Korean Society of Clothing and Textiles
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    • v.41 no.2
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    • pp.341-351
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    • 2017
  • This study evaluates a cleaning method to maintain and minimize the change of blood soil for the selective removal of stains from textiles with historical significance and special meaning. Cotton and silk fabrics were soiled with blood, aged artificially and then washed by wet cleaning or dry cleaning (water, nonionic surfactant; Triton, natural surfactant; saponin, organic solvent; n-Decane). The washed fabrics were stored at room temperature for four years. The change of the blood soil was evaluated by SEM, weight, thickness, and color differences. Subsequently, the shape and the amount of blood adsorption on the fabric varied depending on fiber type and fabric structure characteristics; in addition, long term storage affected changes to blood soil. It was difficult to remove artificially aged blood soil from fabrics by wet or dry cleaning. However, the changes of the blood soil by these cleanings can be explained by the changes on SEM, weight, thickness and fabric color. The changes (especially color) showed over time. Wet cleaning showed that the changes of those factors were slightly lower than those by dry cleaning.

Analysis of Recent 30-year Climate Characteristics by Natural Geography (자연지형 구분에 의한 최근 30년간 기후특성 분석)

  • Ryu, Yeon-Soo;Park, Mi-Lan;Kim, Jin-Wook;Joo, Hye-Jin
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.256-262
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    • 2011
  • Environmental pollution by Using of a fossil fuel, a reckless and growth-oriented development since the Industrial Revolution has caused global change of environment. An issue largest among this is a climate change. A global mean temperature since 19th century has climbed up $0.4{\sim}0.8^{\circ}C$. After The Kyoto Protocol regarding a greenhouse gas reduction goal took effect, be situations that decrease of greenhouse gas was acutely required. Interest of utilization of the new & renewable energy is increasing every day. This study shows that at first divided a country to nine range by natural geography, and second executed Meteorological data analysis of recent 30 years considering level of significance by nine range. The results of this study are that in heating load calculation of building, periodic temperature data management is required because facility capacity and cost are affected greatly by outdoor temperature, and temperature by climate range needs consideration of pertinent area. Lastly, ground temperature was assumed of the weather in region, the ground and soil.

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