• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.495-505
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• 2006

In order to classify aerosol type, Aerosol Optical Thickness (AOT) and Fine mode Fraction (FF), which is the optical thickness ratio of small particles$(<1{\mu}m)$ to total particles, data from MODIS (MODerate Imaging Spectraradiometer) aerosol products were analyzed over North-East Asia during one year period of 2005. A study area was in the ocean region of $20^{\circ}N\sim50^{\circ}N$ and $110^{\circ}E\simt50^{\circ}E$. Three main atmospheric aerosols such as dust, sea-salt, and pollution can be classified by using the relationship between AOT and FF. Dust aerosol has frequently observed over the study area with relatively high aerosol loading (AOT>0.3) of large particles (FF<0.65) and its contribution to total AOT in spring was up to 24.0%. Pollution aerosol, which is originated from anthropogenic sources as well as a natural process like biomass burning, has observed in the regime of high FF (>0.65) with wide AOT variation. Average pollution AOT was $0.31{\pm}0.05$ and its contribution to total AOT was 79.8% in summer. Characteristic of sea-salt aerosol was identified with low AOT (<0.3), almost below 0.1, and slightly higher FF than dust and lower FF than pollution. Seasonal analysis results show that maximum AOT $(0.33{\pm}0.11)$ with FF $(0.66{\pm}0.21)$ in spring and minimum AOT $(0.19{\pm}0.05)$, FF $(0.60{\pm}0.14)$ in fall were observed in the study area. Spatial characteristic was that AOT increasing trend is observed as closing to the eastern part of China due to transport of aerosols from China by the prevailing westerlies.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1687-1698
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• 2021

This study is to produce multiple layers of liposomes in a supercritical state and encapsulates active ingredients in order to stably encapsulate thermodynamically unstable active ingredients. In order to form a liposome in a supercritical state, a mixed surfactant development including vegetable-derived hydrogenated phosphatidyl choline and their delivative, hydrogenated sucrose distearate was synthesized as high purity. It describes a manufacturing method of injecting liquid carbon dioxide into a reactor to create a supercritical state and stirring to produce a giant liposome, and adding and loading genistein and quercetin. The HLB of the mixed lipid complex (SC-Lipid Complex) was 12.50, and multiple layers of liposome vesicles were formed even at very low concentrations. This surfactant had a specific odor with a pale yellow flake, the specific gravity was 0.972, and the acid value was 0.12, indicating that it was synthesized with high purity. As a result of the emulsifying capacity experiment using 20 wt% capric/capric triglyceride and triethylhexanoin using SC-Lipid Complex, it was found to have 96.2% emulsifying power. SC LIPOSOME GENISTEIN was confirmed that a multi-layer liposome vesicle was formed through a transmission electron microscope (Cryo-TEM) for the supercritical liposome encapsulated with genistein. The primary liposome particle size in which genistein was encapsulated was 253.9 nm, and the secondary capsule size was 18.2 ㎛. Using genistein as the standard substance, the encapsulation efficiency of supercritical liposomes was 99.5%, and general liposomes were found to have an efficiency of 93.6%. In addition, the antioxidant activity experiment in which quercetin was sealed was confirmed by the DPPH method, and it was found that the supercritical liposome significantly maintained excellent antioxidant activity. In this study, thermodynamically unstable raw materials were sealed into liposomes without organic solvents in a supercritical state. Based on these results, it is expected that it can be applied to various forms such as highly functional skincare cosmetics, makeup cosmetics, and scalp protection cosmetics.

• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.184-194
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• 2021

Since the construction of a dike in 1983, the water quality in the Bunam Lake has continued to deteriorate due to algal bloom caused by agricultural nutrient loading. Therefore, we evaluated the change in water quality and phytoplankton ecological characteristics in Bunam Lake and Cheonsu Bay, Korea. Water temperature, salinity, dissolved oxygen, chemical oxygen demand (COD), chlorophyll, and phytoplankton community were surveyed in April during the dry season and in July during the rainy reason. As a result, during the dry period, phytoplankton proliferated greatly and stagnated in the Bunam Lake while a very high population of cyanobacteria Oscillatoria spp. (8.61×10⁷ cells L^-1) was recorded. Most of the nutrients, except, nitrate and nitrite, were consumed due to the large growth of phytoplankton. However, during the rainy period, concentrations of ammonia, phosphate, silicate, nitrate, and nitrite, were very high towards the upper station due to the inflow of fresh water. Cyanobacteria Oscillatoria and Microcystis spp. were dominant in the Bunam Lake during the rainy period. Even in the Cheonsu Bay, cyanobacteria dominated due to the effect of discharge and diatoms, such as, Chaetoceros spp. and Eucampia zodiacus, which also proliferated significantly due to increased levels of nutrients. Since the eutrophication index was above 1 in Bunam Lake, it was classified as eutrophic water and the Cheonsu Bay was classified as eutrophic water only during the rainy season. In addition, a stagnant seawater-derived hypoxia water mass was observed at a depth of8m in the Bunam Lake adjacent to the tide embankment and the COD concentration reached 206 mg L^-1 in the bottom layer at B3. Based on this result, it is considered that the water quality will continue to deteriorate if organic matters settle due to continuous inflow of nutrients and growth of organisms while the bottom water mass is stagnant.

• Journal of the Korean Geosynthetics Society
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• v.20 no.4
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• pp.85-93
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• 2021

The seventy percentage of Korean Peninsular is covered by the mountainous area, and the depth of west sea and south sea is relatively shallow. Therefore, a large scale land reclamation from the sea has been implemented for the construction of industrial complex, residental area, and port and airport facilities. The common problem of reclaimed land is consisted of soft ground, and hence it has low load bearing capacity as well as excessive settlement upon loading on the ground surface. The hollow concrete block has been used to reinforce the loose and soft foundation soil where the medium-high apartment or one-story industrial building is being planned to be built. Recently the earthquakes with the magnitude of 4.0~5.0 have been occurred in the west coastal and southeast coastal areas. Lee (2019) reported the advantages of hollow concrete block reinforced shallow foundation through the static laboratory bearing capacity tests. In this study, the dynamic behavior of hollow concrete block reinforced sandy ground with filling the crushed stone in the hollow space has been investigated by the means of shaking table test with the size of shaking table 1000 mm × 1000 mm. Three types of seismic wave, that is, Ofunato, Hachinohe, Artificial, and two different accelerations (0.154 g, 0.22 g) were applied in the shaking table tests. The horizontal displacement of structure which is situated right above the hollow concrete block reinforced ground was measured by using the LVDT. The relative density of soil ground are varied with 45%, 65%, and 85%, respectively, to investigate the effectiveness of reinforcement by hollow block and measured the magnitude of lateral movement, and compared with the limit value of 0.015h (Building Earthquake Code, 2019). Based on the results of shaking table test for hollow concrete block reinforced sandy ground, honeycell type hollow block gives a large interlocking force due to the filling of crushed stone in the hollow space as well as a great interface friction force by the confining pressure and punching resistance along the inside and outside of hollow concrete block. All these factors are contributed to reduce the great amount of horizontal displacement during the shaking table test. Finally, hollow concrete block reinforced sandy ground for shallow foundation is provided an outstanding reinforced method for medium-high building irrespective of seismic wave and moderate accelerations.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.2
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• pp.79-85
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• 2016

Purpose: This study aimed to analyze genetic mutations, clinical manifestations, and treatment of patients with benign HPA in Korea. Methods: This case series study involved ten HPA patients who were referred to our hospital because of high phenylalanine concentration. We investigated their demographic features, clinical manifestations, and mutations of the PAH gene through direct DNA sequencing. Results: Among ten patients with benign HPA, two pairs of patients were related (father-daughter, mother-daughter relationship) cases, and all of them showed no specific clinical manifestations or notable past history. Their plasma phenylalanine levels ranged between 1.2 and 4.2 mg/dL. In the tetrahydrobiopterin (BH4) loading test, all patients were nonresponsive to BH4. In the confirmation test of PAH mutation analysis, we identified eleven different alleles out of twelve. The most common allele was R53H (c.158G> A). In addition, two novel PAH gene mutations, V423A (c.1268T>C) and V51A (c.152T>C), were identified. Although the patients did not receive any pharmacologic treatment or continuous phenylalanine restriction dietary therapy, their neurocognitive development was normal. Moreover, on serial outpatient follow-up tests, all patients maintained phenylalanine levels below 6 mg/dL. Conclusion: This study is the first in Korea to analyze benign HPA patients. All patients with benign HPA could maintain phenylalanine levels below 6 mg/dL with normal neurocognitive development, without continuous therapy. Therefore, performing mutation analysis and distinguishing benign HPA from phenylketonuria (PKU) are important to help improve life quality in patients with benign HPA by avoiding unnecessary lifelong therapy.

• Journal of Biomedical Engineering Research
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• v.25 no.3
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• pp.171-182
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• 2004

This study investigates the biomechanical efficacies of vertebroplasty which is used to treat vertebral body fracture with bone cement augmentation for osteoporotic patients using image and finite element analysis. Simulated models were divided into two groups: (a) a vertebral body, (b) a functional spinal unit(FSU). For a vertebral body model, the maximum axial displacement was investigated under axial compression to evaluate the effect of structural integrity. The stiffness of each FE model simulated was normalized by the stiffness of intact model. In the case of FSU model, 3 types of compression fractures were formulated to assess the influence on spinal curvature changes. The FSU models were loaded under compressive pressure to calculate the change of spinal curvature. The results according to the various factors suggest that vertebroplasty has the biomechanical efficacy of the increment of structural reinforcement in a patient who has relatively high level of BMD and a patient with the amount of 15％, PMMA injection of the cancellous bone volume. The spinal curvatures after compression fracture simulation vary from 9$^{\circ}$ to 17$^{\circ}$ of kyphosis compared to that the spinal curvature of normal model was -2.8$^{\circ}$ of lordosis. These spinal curvature changes cause the severe spinal deformity under the same loading. As the degree of compressive fracture increases the spinal deformity also increases. The results indicate that vertebroplasty has the increasing effect of the structural integrity regardless of the amount of PMMA or BMD and the restoration of decreased vertebral body height may be an important factor when the compressive fracture caused the significant height loss of vertebral body.

• Journal of the Korea Concrete Institute
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• v.19 no.1
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• pp.121-130
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• 2007

To investigate the enhancement in strength and deformation capacities of concrete confined by FRP composites, tests under axial loads were carried out on three groups of thirty six short columns in circular section with diverse GFRP confining reinforcement. The major test variables considered include fiber content or orientation, wrap or tube type by varying the end loading condition, and continuous or discontinuous confinement depending on the presence of vortical spices between its two halves. The circumferential FRP strains at failure for different types of confinements were also investigated with emphasis. Various analytical models capable of predicting the ultimate strength and strain of the confined concrete were examined by comparing to observed results. Tests results showed that FRP wraps or tubes provide the substantial increase in strength and deformation, while partial wraps comprising the vertical discontinuities fail in an explosive manner with less increase in strength, particularly in deformation. A bilinear stress-strain response was observed throughout all tests with some variations of strain hardening. The failure hoop strains measured on the FRP surface were less than those obtained from the tensile coupons in all tests with a high degree of variation. In overall, existing predictive equations overestimated ultimate strengths and strains observed in present tests, with a much larger scatter related to the latter. For more accuracy, two simple design- oriented equations correlated with present tests are proposed. The strength equation was derived using the Mohr-Coulomb failure criterion, whereas the strain equation was based on entirely fitting of test data including the unconfined concrete strength as one of governing factors.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.170-174
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• 1997

Constructed wetland system was studied to treat wastewater from industrial complex in rural area. Pilot plant at the Baeksuk Nongkong Danzi in Chunahn-City was used for field study. For the DO, the effluent concentration was higher than the influent concentration and it implies that natural reaeration supplies enough oxygen to the system. For the SS, the effluent concentration was consistently lower than the water quality standard even though the influent concentration varied significantly, which showed that SS was removed by the system effectively which is consist of soil and plants. For the BOD and COD, the average removal rate of them were 56% and 43%, respectively, therefore, the effluent concentration could not meet water quality standards when influent concentration was high. The removal rate of BOD and COD can be improved by supplemental treatment in addition to this system if necessary. For the T-N and T-P, the influent concentration of them were lower than the water quality standards than no further treatment was needed. Overall, the result showed that constructed wetland system is a feasible alternative for the treatment of wastewater from industrial complex in rural area. For actual application of this system, further study on design factors including loading rate, removal mechanism, and temperature effects is required to meet water quality standard consistently. Compared to existing systems, this system is quite competitive because it requires low capital cost, almost no energy and maintenance, and therefore, very cost effective.

• Pediatric Infection and Vaccine
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• v.21 no.1
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• pp.9-21
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• 2014

Purpose: To determine the clinical significance of voriconazole therapeutic drug monitoring (TDM) in the pediatric population. Methods: Twenty-eight patients with invasive fungal infections administered with voriconazole from July 2010 to June 2012 were investigated retrospectively. Fourteen received TDM, and 143 trough concentrations were analyzed. All 28 patients were assessed for adverse events and treatment response six weeks into treatment, and at the end. Results: Out of 143 samples, 53.1% were within therapeutic range (1.0-5.5 mg/L). Patients administered with the same loading (6 mg/kg/dose) and maintenance (4 mg/kg/dose) dosages prior to initial TDM showed highly variable drug levels. Adverse events occurred in 9 of 14 patients (64.3%) in both the TDM and non-TDM group. In the TDM group, voriconazole-related encephalopathy (n=2, 14.3%) and aspartate aminotransferase (AST) or alanine aminotransferase (ALT) elevation (n=8, 57.1 %) occurred with serum levels in the toxic range (>5.5 mg/L), whereas blurred-vision (n=2, 14.3%) occurred within the therapeutic range (1.18 mg/L and 3.9 mg/L). The frequency of voriconazole discontinuation due to adverse events was lower in the TDM group (0.0% vs. 18.2%, P =0.481). Overall, 57.2% of the patients in the TDM group versus 14.3% in the non-TDM group showed clinical response after 6 weeks (P =0.055), whereas 21.4% in the TDM group versus 14.3% in the non-TDM group showed response at final outcome (P =0.664). In the TDM group, >67.0% of the serum levels were within therapeutic range for the first 6 weeks; however 45.5% were within therapeutic range for the entire duration. Conclusion: Routine TDM is recommended for optimizing the therapeutic effects of voriconazole.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1298-1304
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• 2005

This study was performed to evaluate the characteristics of the competition between two electron acceptors, perchlorate and nitrate, with Citrobacter Amalonaticus strain JB101. In addition, the applicability of membrane bioreactor(MBR) for perchlorate removal was evaluated. The maximum growth rate of strain JB101 on perchlorate and nitrate are 0.27 and 0.58 $hr^{-1}$, and maximum substrate utilization rates were 35.1 mg $ClO_4^-/g$ protein-day and 45.6 mg $NO_3^-/g$ protein-day, respectively. Nitrate was a competitive inhibitor for perchlorate, and strain JB101 prefer nitrate to perchlorate as electron acceptor. Complete removal of perchlorate could be achieved up to the surface leading rate of 4.6 g $ClO_4^-/m^2-day$ with the MBR fed with 20 mg $ClO_4^-/L$(HCMBR). When 5 mg/L of nitrate was added to the same influent, perchlorate removal efficiency decreased to 96.5%, while nitrate was completely removed. For the MBR fed with 0.7 mg/L of perchlorate (LCMBR), the maximum perchlorate removal efficiency was 100% up to the loading rate of 0.23 g $ClO_4^-/m^2-day$. Membrane fouling was found to be a problem at high leading rate for both MBRs. The acetate consumption ratio per perchlorate was $13.7{\sim}51.7\;e^-eq./e^-eq.$ in LCMBR, while the value was $2.5{\sim}3.6\;e^-eq./e^-eq.$ in HCMBR. This difference could be related to the acetate consumption with oxygen as electron acceptor. Therefore, the amount of acetate addition must be determined considering the concentrations of other electron acceptors in the influent.