• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.311-324
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• 1992

Polymeric substances in organic matter of soils aggregate soil particles into a crumb structure which greatly influences such properties as water movement, aeration and heat transfer. Poorly-structured soils may be improved by the incorporation of synthetic polymers where the main objects are : promoting germination or establishing crops, improving drainage, combating wind and water erosion, and reducing evaporation from the surface of soil under arid condition.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.184-188
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• 1997

To investigate the absorption and transfer factor(TF) of Sr-85 by rice(Oryza sativa L.), experiments were carried out through pot cultivations on a sandy-loam soil treated 74 and 222Bq per gram of soil in a plastic film house. Sr-85 absorption rates of Ilpoombyeo, late maturing variety and Odaebyeo, early maturing variety, at harvesting stage, were 0.39-0.43% and 0.66-0.73%, respectively. Sr-85 absorption rates of Odaebyeo were about 1.5 times higher than those of Ilpoombyeo. Ratios of Sr-85 radiation and Sr-85 concentration in brown rice were much lower compared with those in straw and husk. Sr-85 concentrations in each part of Odaebyeo were remarkably higher than those of Ilpoombyeo. Transfer factor of Sr-85 from soil to plant ranged from 0.037 of brown rice to 4.13 of rice straw at harvesting stage. The order of the Sr-85 transfer factor in plant parts was straw>husk>brown rice. Sr-85 concentrations treated in soil had no effect on the growth and yield of rice.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.201-206
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• 2010

Two male reticulated giraffes (Giraffa camelopardalis reticulata), 21-year-old, died of nutritional deficiency that primarily caused by serious tooth wear at Seoul Zoo in winter. A 970 kg-weighed giraffe showed tooth wear of premolars, molars and incisors at necropsy. A foreign body in the rumen, congestion and ulcer of abomasum and duodenum were also observed. Mild appearance of serous fat atrophy in pericardial sac suggests that lack of nutritional intake caused by tooth wear can become harmful enough to threat life. At the necropsy of a 1,290 kg-weighed giraffe, a large quantity of sandy soil were found in the rumen which would stuck the pathway of well-fermented ruminal contents at esophageal groove. Nutritional deficiency could be suspected to urge this giraffe to graze grass on the ground along with sandy soil. Secondarily, the soil damaged teeth and become a culprit making irregular tooth wear and mild serous fat atrophy. Nutritionally good care of geriatric animals is needed especially for browsing animals like giraffes and critically in winter season.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.391-398
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• 2014

Identifying soil water content as a major factor for evaluating irrigation and water resource is a primary module to develop a prediction model. A variety of PTFs (Pedo-Transfer Functions) are applied in the models to estimate soil water content, the analysis techniques, however, which compare the estimated from models and the measured by instruments, are not reached at the level to demonstrate the effectiveness of the PTFs in Korea. Many soil physicians such as Eom, Peterson, Rawls, Saxton, Bruand, Baties, Tomasella & Hodnett (T&H), and Minasny, have developed analytic models using PTFs. Soil data for the analysis used soil water contents on 347 soil series (10 kPa), 358 soil series (33 kPa), 356 soil series (1,500 kPa) established by NAAS (National Academy of Agricultural Science). A coefficient of determination on soil water content at 10, 33 and 1,500 kPa was the highest as 0.5932 in EM (Eom model), 0.6744 in REM (Rawls model) and 0.6108 in REM, respectively. In conclusion, it is strongly suggested that the use of EM or REM is suitable for estimating soil water content in Korea although SM (Saxton model) has been widely used.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.232-235
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• 1998

Air sparging system is a kind of in-situ bioremediation method in the contaminated ground water. When Air sparging, the both of water circulation and oxygen transfer happend in the same time. The hydraulic differential head is zero at the middle height of well, is negative below the height and is possitive above the height. Hydroraulic head gradient is proportioned to air superficial velocity in the well. But over 24m/min of the superficial velocity, the hydraulic head gradient increase little.

• Proceedings of the Korean Geotechical Society Conference
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• 1997.10a
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• pp.357-364
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• 1997

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.2
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• pp.35-46
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• 2008

Soil moisture is one of the important components in hydrological processes and also controls the subsurface flow mechanism at a hillslope scale. In this study, time series of soil moisture were measured at a hillslope located in Gwangneung National Arboretum, Korea using a multiplex Time Domain Reflectometry(TDR) system measuring soil moisture with bi-hour interval. The Box-Jenkins transfer function and noise model was used to estimate spatial distributions of soil moisture histories between May and September, 2007. Rainfall was used as an input parameter and soil moisture at 10 cm depth was used as an output parameter in the model. The modeling process consisted of a series of procedures(e.g., data pretreatment, model identification, parameter estimation, and diagnostic checking of selected models), and the relationship between soil moisture and rainfall was assessed. The results indicated that the patterns of soil moisture at different locations and slopes along the hillslope were similar with those of rainfall during the measurment period. However, the spatial distribution of soil moisture was not associated with the slope of the monitored location. This implies that the variability of the soil moisture was determined more by rainfall than by the slope of the site. Due to the influence of vegetation activity on soil moisture flow in spring, the soil moisture prediction in spring showed higher variability and complexity than that in early autumn did. This indicates that vegetation activity is an important factor explaining the patterns of soil moisture for an upland forested hillslope.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.535-542
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• 1994

Remote sensing technique is based on the estimation of land surface characteristics from the measurement of the emitted radiation from the earth. The hydrologically related parameters studied using this approach include surface temperature, evapotranspiration, soil moisture, precipitation and snow. This study introduces a method for estimating moisture content of a bare soil from the observed and simulated brightness temperature. In a bare soil, microwave emission depends on moisture content, soil temperature, and surface roughness. The method is based on a radiative transfer model with some modifications of Fresnel reflection coefficient to take into account the effect of surface roughness. One smooth bare field and two fields with different surface roughness are prepared for the study. The results indicate that the effect of surface roughness is to increase the soil's brightness temperature and to reduce the slope of regression between brightness temperature and moisture contents.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.216-219
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• 2006

Water retention curve (WRC), one of soil hydraulic properties, is often approximated by property-transfer models (PTMs). Using the PTMs, we can estimate the WRCs from other physical properties such as particle-size distribution (PSD). The objective of this work was to investigate the performance of two PTMs with different origins for numerical simulations on transport of Benzo[a]pyrene in a soil. To do this, we chose both PTMs with different origins, i.e., (1) the lognormal distribution model (L anti NL models), and (2) the modified $Kov\'{a}cs$ model (MK model). The MK model showed tile worse performance in estimation of the WRCs. When transport of B[a]P was simulated, the MK model predicted to move farther than the L and NL models did, indicating that transport of B[a]P in a soil can be greatly influenced by the choice of PTMs.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.896-901
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• 2009

A Soil Nail is a structural element which provides load-transfer to the ground in excavation reinforcement applications. The nail may simply consist of a steel tendon, but most commonly the tendon is encapsulated in a cement grouted body to provide corrosion protection and improved load- transfer to the ground. For temporary excavation support in a congested urban area, the steel bar of Soil Nails should be removed to get permission of the private land to install Soil Nails. Several removable nail systems were developed and evaluated by pull-out load tests. The Soil Nail pull-out tests were performed on five nails installed in soft and hard rock at a 00 housing-redevelopment area in seoul. Two nails are plastic socket type and two are complex socket type mixed steel and plastic. The nail was 0.1mm in diameter, 4m long. In this study verification tests, and steel bar removing tests of plastic socket type nails and complex socket type nails were performed and presented.