• Journal of Wetlands Research
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• v.13 no.2
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• pp.231-242
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• 2011

Recently, the green spaces in the urban areas were greatly reduced due to urbanization and industrialization. As urban structures such as roads and buildings are built, the amount of impervious area within a watershed increases. High impervious surfaces are the common causes of high runoff volumes as the soil infiltration capacity decreases and the volume and rate of runoff increase thereby decreasing the groundwater recharge. These effects are causing many environmental problems, such as floods and droughts, climate change, heat island phenomenon, drying streams, etc. Most cities attempted to reduce sewer overflows by separating combined sewers, expanding treatment capacity or storage within the sewer system, or by replacing broken or decaying pipes. However, these practices can be enormously expensive than combined sewer overflows. Therefore, in order to improve these practices, alternative methods should be undertaken. A new approach termed as "Low Impact Development (LID)" technology is currently applied in developed countries around the world. The purpose of this study was to effectively manage runoff by adopting the LID techniques. Small Constructed Wetland(Horizontal Subsurface Flow, HSSF) Pilot-scale reactors were made in which monitoring and experiments were performed to investigate the efficiency of the system in removing pollutants from runoff. Based on the results of the Pilot-plant experiments, TSS, $COD_{Cr}$, TN, TP, Total Pb removal efficiency were 95, 82, 35, 91 and 57%, respectively. Most of the pollutants were reduced after passing the settling tank and the vertical filter media. The results of this study can contribute to the conservation of aquatic ecosystems and restoration of natural water cycle in the urban areas.

• Tuberculosis and Respiratory Diseases
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• v.40 no.6
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• pp.730-735
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• 1993

BOOP is a clinopathologic entity consisting of a flu-like illness, late inspiratory crackles, and pathologically granulation tissue plugs within lumens of small airways sometimes with complete obstruction of small airways and granulation tissue extending into alveolar ducts and alveoli with a variable degree of interstitial infiltration of mononuclear cells and accumulation of foamy macrophages in alveolar spaces in a patch distribution, and preservation of background architecture of the lung. It has patch infiltrates roentgenographically, and restrictive ventilatory defect pysiologically such as decreased vital capacity. and diffusing capacity. The BOOP has been observed in the context of collagen vascular disease, and other autoimmune disease secondary to treatment with penicillamine, bleomycin, acebutolol and amiodarone, following the inhalation of toxic fumes, after several infections including measles, pertussis and influenza and idiopathic. Clinically, response to coricosteroid therapy is good and relapse dose not occur if sufficient theraphy is good. A flu-like illness occurs in one third, cough in one third, cough with dyspnea in the remaining patients. Hemoptysis are rare. The physical examination reveales dry crackles in the majority of the patients with BOOP but rarely associated with wheezing. The duration of illness is less than 2 months in 75% of patients. With a brief review of literature, we report a case of the BOOP which is good response to steroid, but frequent relapse and assoicated with wheezing.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.2
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• pp.123-129
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• 1995

For the propose of increasing the value added, zeolite powder was granulated by adding Polyvinyl Alcohol (PVA) as cementing material. The optimal concentration of PVA for granulation and the physical properties of the prepared granule were investigated. Four percent PVA stock solution was made by adding distilled water at $90^{\circ}C$ water bath and incorporated with zeolite. The contents of water stable granule above 2.0mm in diameter was 98.0% in the case of 0.3% PVA addition and almost 100% in the case of 0.6% PVA addition. Increasing PVA concentration of granules increased the hardness and decreased the infiltration rate and the maximum water holding capacity of granules, However, the drying method hardly affected the physical properties of granules. With the increase in the mixing ratios of kaolinite or bentonite to zeolite, the hardness of granules increased but high water contents of granules resulted in rapid decrease in the hardness of granules. However, when smectite or perlite was mixed with zeolite, the increase in mixing ratios to zeolite resulted in the decrease in hardness, the increase in the infilteration rate and maximum water holding capacity of granules.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.204-208
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• 2012

Water repellency which affects infiltration, evaporation, erosion and other water transfer mechanisms through soil has been observed under several natural conditions. Water repellency is thought to be caused by hydrophobic organic compounds, which are present as coatings on soil particles or as an interstitial matter between soil particles. This study was conducted to evaluate the characteristics of the water repellent soil and transport characteristics of trace elements within this soil. Capillary height of the water repellent soil was measured. Batch and column studies were accompanied to identify sorption and transport mechanism of trace elements such as $Cu^{2+}$, $Mn^{2+}$, $Fe^{2+}$, $Zn^{2+}$ and $Mo^{5+}$. Difference of sorption capacity between common and repellent soils was observed depended on the degree of repellency. In the column study, the desorption of trace elements and the spatial concentration distribution as a function of time were evaluated. The capillary height was in the repellency order of 0% > 15% > 40% > 70% > 100%. No water was absorbed in soil indicating >70% repellency. Using trace elements, $Fe^{2+}$ and $Mo^{5+}$ showed higher sorption capacity in the repellent soil than in non-repellent soil. The sorption performance of $Fe^{2+}$ was found to be in the repellency order of 40% > 15% > 0%. Our results found that transfer of $Mo^{5+}$ had similar sorption tendency in soils having 0%, 15% and 40% repellency at the beginning, however, the higher desorption capacity was observed as time passes in the repellent soil compared to in non-repellent soils.

• Asian Journal of Turfgrass Science
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• v.18 no.3
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• pp.149-163
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• 2004

Physical and chemical properties of root zone mixes and methods of green construction are important considerations for improving turf grass quality for putting greens. This study compared Penncross creeping bentgrass (Agrostis palustris Huds.) performance as affected by three root zone construction systems with three amendments (sand, peat, and zeolite). The objective of this study was to determine if an amended California construction system would improve green performance during establishment (1998-1999) and maturation (2000-2001). Three treatments were tested: California ($100\%$ sand), USGA($90\%$ sand and $10\%$ peat, v/v), and California-Z ($85\%$ sand and $15\%$ zeolite, v/v). Treatments were arranged in a randomized complete block with four replicates. Physical and chemical properties of the root zone and bentgrass performance were compared for the treatments. The California-Z treatment had the highest saturated hydraulic conductivity, field infiltration rate and the lowest bulk density. It also had the highest cation exchange capacity and plant available nutrient concentrations among the three treatments. The California-Z treatment produced bentgrass quality and color during green establishment and maturation that were equal to or higher than the California treatment, and consistently higher than the USGA treatment. The addition of an inorganic amendment to the California system improved physical and chemical properties of the root zone and improved quality and color of bentgrass during green establishment. During green maturation, creeping bentgrass in the California-Z treatment was equal (6 of 15 sampling dates) or $20\%$ higher (9 of 15 dates) in quality compared to the California system.

• Journal of Korea Water Resources Association
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• v.49 no.6
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• pp.565-577
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• 2016

The objective of this study is to propose a method for computing the Natural Drought Index (NDI) that does not consider man-made drought facilities. Principal Component Analysis (PCA) was used to estimate the NDI. Three monthly moving cumulative runoff, soil moisture and precipitation were selected as input data of the NDI during 1977~2012. Observed precipitation data was collected from KMA ASOS (Korea Meteorological Association Automatic Synoptic Observation System), while model-driven runoff and soil moisture from Variable Infiltration Capacity Model (VIC Model) were used. Time series analysis, drought characteristic analysis and spatial analysis were used to assess the utilization of NDI and compare with existing SPI, SRI and SSI. The NDI precisely reflected onset and termination of past drought events with mean absolute error of 0.85 in time series analysis. It explained well duration and inter-arrival time with 1.3 and 1.0 respectively in drought characteristic analysis. Also, the NDI reflected regional drought condition well in spatial analysis. The accuracy rank of drought onset, termination, duration and inter-arrival time was calculated by using NDI, SPI, SRI and SSI. The result showed that NDI is more precise than the others. The NDI overcomes the limitation of univariate drought indices and can be useful for drought analysis as representative measure of different types of drought such as meteorological, hydrological and agricultural droughts.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.1
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• pp.63-79
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• 1993

To repair bony defects with tansplanted bone in the body, fresh autogenous bone is undoubtly, the most effective bone graft for clinical applications. But the demineralized bone has the matrix-induced bone formation which was suggested by Urist in 1965. Many authors assisted that demineralized bone powder induces phenotypic conversion of mesenchymal cells into osteoblasts, with high-density bone formation. The process of inducing differentiated cells becomes osteogenic properties. The purpose of this study was to evaluate the osteoinductive capacity of allogenic freeze-dried demineralized bone block (FDD, $7{\times}7mm$) and to compare FDD with the same sue of deep-frozen allogenic bone(DF), fresh autogenous bone (A) after implantation. The histological and ultrastructural features of tissue responses were examined after 1, 2, 4, 6, 8 weeks implantation of each experimental groups in the operative site of the New Zealand white rabbits. The results were as follows : 1. Inflammatory cell infiltration generally has appeared at 1 week, but reduced at 4 weeks in each group, but most severe in DF group. 2. Osteoblastic activity has increased for 4 weeks, but decreased at 6 weeks in each group and there was no significant difference among experimental groups. 3. New bone formation has begun at 1week, least activations in A groups, and showed the revesal line of bone formation among each group at 6 to 8 weeks. 4. Bone resorption has appeared at 1 week, but disappeared at 4 weeks in both A and DF groups, but more severe in DF than A groups. 5. In ultrastructural changs, the DF group have showed the most remarkable osteoclastic activities among experimental groups. 6. Osteoid or tangled collagen fibrils near the implanted sites were replaced by more mature, lamellated bony trabeculae during bone remodeling. There was little difference among each experimental groups. 7. During the convertion osteoblasts to osteocytes which embedded within the bone matrix, there was organ-less-poor cytoplasm, increased nuclear chromatin, abundant rough endothelial reticulum (RER) in each groups. From the above the findings, the DF group shored more bone resorption and foreign body reaction than FDD and A groups, and FDD group showed more new bone formation or osteoblastic activity than DF and A groups in early stage. There was no significant difference of cellular activities among the FDD DF, and A groups according to the time.

• Journal of Korea Water Resources Association
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• v.50 no.4
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• pp.223-232
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• 2017

The ability to defend against floods in urban areas was weakened, because the increase in the impervious rate of urban areas due to urbanization and industrialization and the increase in the localized torrential rainfall due to abnormal climate. In order to reduce flood damage in urban areas, various runoff reduction facilities such as detention ponds and infiltration facilities were installed. However, in the case of domestic metropolitan cities, it is difficult to secure land for the installation of storm water reduction facilities and secure the budget for improving the aged pipelines. Therefore, it is necessary to design a storage system (called the detention pond in trunk sewer) that linked the existing drainage system to improve the flood control capacity of the urban area and reduce the budget. In this study, to analyze the effect of reducing runoff amounts according to the volume of the detention pond in trunk sewer, three kinds of virtual watershed (longitudinal, middle, concentration shape) were assumed and the detention pond in trunk sewer was installed at an arbitrary location in the watershed. The volume of the detention pond in trunk sewer was set to 6 cases ($1,000m^3$, $3,000m^3$, $5,000m^3$, $10,000m^3$, $20,000m^3$, $30,000m^3$), and the installation location of the detention pond in trunk sewer was varied to 20%, 40%, 60%, and 80% of the detention pond upstream area to the total watershed area (DUAR). Also, using the results of this study, a graph of the relationship and relational equation between the volume of the detention pond in trunk sewer and the installation location is presented.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.119-128
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• 2008

Sewer rehabilitation is performed to improve the problem for urban drainage sewer system recently. However the data for the sewer system is not stored enough so that the sewer system is difficult to be managed systematically. In this study, a maintenance management system for urban drainage system is developed to store the data efficiently and manage the system systematically. In the developed system, a hydraulic and hydrologic analysis module is included to test the carrying capacity of a sewer pipe and estimate the amount of combined sewer overflows. The I/I and superannuation evaluation module is included in this system. The module distribute the total inflow/infiltration observed at the several sampling points in a drainage area to the individual pipes of the entire sewer system. Then the superannuation of a sewer pipe is evaluated according to the amount of I/I of the pipe. And in the developed system, the optimal rehabilitation priority module is included to determine the optimal priority and support the decision making for the sewer rehabilitation. The maintenance management system which is developed in this study is constructed by the association with the developed modules and the system is formed as graphical user interface system.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.1
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• pp.1-16
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• 2004

The use of artificial nerve conduit containing viable Schwann cells is one of the most promising strategies to repair the peripheral nerve injury. To fabricate an effective nerve conduit whose microstructure and internal environment are more favorable in the nerve regeneration than existing ones, a new three-dimensional Schwann cell culture technique using $Matrigel^{(R)}$. and dorsal root ganglion (DRG) was developed. Nerve conduit of three-dimensionally arranged Schwann cells was fabricated using direct seeding of freshly harvested DRG into a $Matrigel^{(R)}$ filled silicone tube (I.D. 1.98 mm, 14 mm length) and in vitro rafting culture for 2 weeks. The nerve regeneration efficacy of three-dimensionally cultured Schwann cell conduit (3D conduit group, n=6) was assessed using SD rat sciatic nerve defect of 10 mm, and compared with that of silicone conduit filled with $Matrigel^{(R)}$ and Schwann cells prepared from the conventional plain culture method (2D conduit group, n=6). After 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were examined using image analyzer and electromicroscopic methods. The SFI and ankle stance angle (ASA) in the functional evaluation were $-60.1{\pm}13.9$, $37.9^{\circ}{\pm}5.4^{\circ}$ in 3D conduit group (n=5) and $-87.0{\pm}12.9$, $32.2^{\circ}{\pm}4.8^{\circ}$ in 2D conduit group (n=4), respectively. And the myelinated axon was $44.91%{\pm}0.13%$ in 3D conduit group and $13.05%{\pm}1.95%$ in 2D conduit group to the sham group. In the TEM study, 3D conduit group showed more abundant myelinated nerve fibers with well organized and thickened extracellular collagen than 2D conduit group, and gastrocnemius muscle and biceps femoris tendon in 3D conduit group were less atrophied and showed decreased fibrosis with less fatty infiltration than 2D conduit group. In conclusion, new three-dimensional Schwann cell culture technique was established, and nerve conduit fabricated using this technique showed much improved nerve regeneration capacity than the silicone tube filled with $Matrigel^{(R)}$ and Schwann cells prepared from the conventional plain culture method.