• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.69-80
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• 2007

Among the photoactive semiconductors such as $TiO_2,\;ZnO,\;Fe_2O_3,\;WO_3,\;and\;CdSe,\;TiO_2$ is the most widely used as photocatalyst in different media, because of its lack of toxicity and stability. In this study, the effects of titanium dioxide were investigated to obtain the information of physiological change in rice plant. Light-adapted Chlorophyll flourescence index decreased and relative electron transport rate of rice leaves was activated by titanium dioxide under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}$ PAR (Photosynthetic active radiation). Relative electron transport rate of rice leaf treated with titanium dioxide 10 ppm was high in order of $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;2,200\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;450\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$ and titanium dioxide 10 ppm (45.1%), control (32.4%), diuron 10 ppm (15.3%) under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$. Titanium dioxide increased photosynthesis of the rice leaf under $13.6\;KJ\;m^{-2}\;day^{-1}$ UV-B only. With titanium dioxide 20 ppm, reduced UV-B ($0.15\;KJ\;m^{-2}\;day^{-1}$) intensity changed the induction of proteins and twenty-five proteins were identified. Among them, seventy proteins were up-regulated, four proteins were down-regulated and four proteins were newly synthesized. Function of these proteins was related to photosynthesis (52%), carbohydrate metabolism (4%), stress/defense (8%), secondary metabolism (4%), energy/electron transport (4%), and miscellaneous (28%).

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.77-82
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• 1999

Three floating islands have been constructed for water quality improvement for a polluted irrigation reservoir. Each floating island consists of 10 segments. Each segment hay an area of $16m^2$(4×4m) and is made of wood frames and floats(polystyrene foam). We planted three species of aquatic macrophytes(Typha angustifolia, Zizania latifolia, and Phragmites australis) in floating island on June, 1998. They grew very well without death. We would like to evaluate Phragmites australis is the most suitable aquatic macrophyte that could be planted in a floating island because it maintained the best balance of its root and shoot among them. During their grown period, net primary productivity of Typha angustifolia was $962gDM/m^2$, Zizania latifolia was $1,115gDM/m^2$, and Phragmites australis was $523gDM/m^2$. From these data, it would be estimated to 5.0Kg uptake of nitrogen by aquatic macrophytes and phosphorus 0.8Kg in 3 floating islands. The floating islands worked well as a habitat of fish and prawns. Many kinds of insect lived on the floating islands. The floating island has not only the function of water quality treatment but also several advantages: improvement of landscape and species diversity; low cost of maintenance; low technology; unnecessary of energy; less susceptible to variations in pollutant loading. It could be evaluated a good measure of water quality improvement for an irrigation reservoir. However, it should be intensively studied to develop more light, strong, durable and low-priced frames for efficient floating islands.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.3
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• pp.430-446
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• 2018

To improve understanding of the sources and chemical properties of particulate pollutants on the Korean Peninsula, An Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) measured non-refractory fine particle ($NR-PM_1$) from 2013 to 2015 at Baengnyeong Island and Seoul metropolitan area (SMA), Korea. The chemical composition of $NR-PM_1$ in Baengnyeong island was dominated by organics and sulfate in the range of 36~38% for 3 years, and the organics were the dominant species in the range of 44~55% of $NR-PM_1$ in Seoul metropolitan area. The sulfate was found to be more than 85% of the anthropogenic origin in the both areas of Baengnyeong and SMA. Ratio of gas to particle partition of sulfate and nitrate were observed in both areas as more than 0.6 and 0.8, respectively, representing potential for formation of additional particulate sulfate and nitrate. The high-resolution spectra of organic aerosol (OA) were separated by three factors which were Primary OA(POA), Semi-Volatility Oxygenated Organic Aerosol (SV-OOA), and Low-Volatility OOA(LV-OOA) using positive matrix factorization (PMF) analysis. The fraction of oxygenated OA (SOA, ${\fallingdotseq}OOA$=SV-OOA+LV-OOA) was bigger than the fraction of POA in $NR-PM_1$. The POA fraction of OA in Seoul is higher than it of Baengnyeong Island, because Seoul has a relatively large number of primary pollutants, such as gasoline or diesel vehicle, factories, energy facilities. Potential source contribution function (PSCF) analysis revealed that transport from eastern China, an industrial area with high emissions, was associated with high particulate sulfate and organic concentrations at the Baengnyeong and SMA sites. PSCF also presents that the ship emissions on the Yellow Sea was associated with high particulate sulfate concentrations at the measurement sites.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.1
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• pp.49-64
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• 2014

Seabed beneath and near the coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If the liquefaction occurs in the seabed, the structure may sink, overturn, and eventually fail. Especially, the seabed liquefaction behavior beneath a gravity-based structure under wave loading should be evaluated and considered for design purpose. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using 2-dimensional numerical wave tank. The 2-dimensional numerical wave tank was expanded to account for irregular wave fields, and to calculate the dynamic wave pressure and water particle velocity acting on the seabed and the surface boundary of the structure. The simulation results of the wave pressure and the shear stress induced by water particle velocity were used as inputs to a FLIP(Finite element analysis LIquefaction Program). Then, the FLIP evaluated the time and spatial variations in excess pore water pressure, effective stress and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the analysis, when the shear stress was considered, the liquefaction at the seabed in front of the structure was identified. Since the liquefied seabed particles have no resistance force, scour can possibly occur on the seabed. Therefore, the strength decrease of the seabed at the front of the structure due to high wave loading for the longer period of time such as a storm can increase the structural motion and consequently influence the stability of the structure.

• Development and Reproduction
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• v.14 no.4
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• pp.287-295
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• 2010

It was recently reported that nesfatin-1/NUCB2, which is secreted from the brain, controls appetite and energy metabolism. The purpose of this research was to confirm whether or not the protein and its binding site should have been expressed in the mouse reproductive organs and to know the possible effects of nesfatin-1 on the reproductive function. Using the ICR female mouse ovary and uterus, the expression of NUCB2 mRNA was confirmed with the conventional PCR and the relative amount of NUCB2 mRNA in the tissues was analyzed with real-time PCR. Immunohistochemical staining was performed using the nesfatin-1 antibody to investigate the nesfatin-1 protein expression and the biotin conjugated nesfatin-1 to confirm the binding site for nesfatin-1 in the ovary. Furthermore, in order to examine if the expression of NUCB2 mRNA in the ovary and uterus is affected by gonadotropin, its mRNA expression was analyzed after PMSG administration into mice. As a result, the expression level of NUCB2 mRNA in the ovary and the uterus was as much as the expression level in hypothalamus. As a result of the immunohistochemical staining, nesfatin-1 proteins were localized at the theca cells, the interstitial cells, and some of the luteal cells. However, the granulosa cells in the follicles did not stain. Interestingly, the oocytes in the some follicles were stained with nesfatin-1. On the other hand, nesfatin-1 protein binding sites were displayed at the theca cells and the interstitial cells near the tunica albuginea. After PMSG administration the expression level of NUCB2 mRNA was increased in the ovary and the uterus. These results demonstrate that for the first time the nesfatin-1 and its binding site were expressed in the ovary and NUCB2 mRNA expression was controlled by gonadotropin, suggesting an important role in the reproductive organs as a local regulator. Therefore, further study is needed to elucidate the functions of nesfatin-1 on the reproductive organs.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.189-196
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• 2012

Purpose: The sufficiency of skin dose and the reemergence of patient set-up position to the success of skin cancer radiation treatment is a very important element. But the conventional methods to increase the skin dose were used to vacuum cushion, bolus and water tank have several weak points. For this reason, we producted Foxtail Millet Vacuum Cushion and evaluated the efficiency of the Foxtail Millet Vacuum Cushion in skin cancer Radiation treatment. Materials and Methods: We measured absolute dose for 3 materials (Foxtail Millet Vacuum Cushion, bolus and solid water phantom) and compared each dose distribution. We irradiated 6 MV 100 MU photon radiation to every material of 1 cm, 2 cm, 3 cm thickness at three times. We measured absolute dose and compared dose distribution. Finally we inspected the CT simulation and radiation therapy planing using the Foxtail Millet Vacuum Cushion. Results: Absolute dose of Foxtail Millet Vacuum Cushion was similar to absolute dose of bolus and solid water phantom's result in each thickness. it Showed only the difference of 0.1~0.2% between each material. Also the same result in dose distribution comparison. About 97% of the dose distribution was within the margin of error in the prescribed ranges ($100{\pm}3%$), and achieved the enough skin dose (Gross Tumor Volume dose : $100{\pm}5%$) in radiation therapy planing. Conclusion: We evaluated important fact that Foxtail Millet Vacuum Cushion is no shortage of time to replace the soft tissue equivalent material and normal vacuum cushion at the low energy radiation transmittance. Foxtail Millet Vacuum Cushion can simultaneously achieve the enough skin dose in radiation therapy planing with maintaining normal vacuum cushion' function. Therefore as above We think that Foxtail Millet Vacuum Cushion is very useful in skin cancer radiation treatment.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.1
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• pp.1-12
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• 1991

An experiment has been carefully designed and performed to verify the theory for the echointergration technique of estimating the density of fish school by the use of steel spheres in a laboratory tank. The spheres used to simulate a fish school were randomly distributed throughout the insonified volume to produce the acoustic echoes similar to those scattered from real fish schools. The backscattered echoes were measured as a function of target density at tow frequencies of 50kHz and 200kHz. Data acquisition, processing and analysis were performed by means of the microcomputer-based sonar-echo processor including a FFT analyzer. Acoustic scattering characteristics of a 36cm mackerel was investigated by measuring fish echoes with frequencies ranging from 47.8kHz to 52.0kHz. The fluctuation of bottom echoes caused by the effects of fish-school attenuation and multiple scattering which occurred in dense aggregations of fishes was also examined by analyzing the echograms of sardine schools obtained by a 50kHz telesounder in the set-net's bagnet, and the echograms obtained by a scientific echo sounder of 50kHz in the East China Sea, respectively. The results obtained can be summarized as follows: 1. The measured and the calculated echo shapes on the steel sphere used to simulate a fish school were in close agreement. 2. The waveform and amplitude of echo signals by a mackerel without swimbladder fluctuated irregularly with the measuring frequency. 3. When a collection of 30 targets/m super(3) lied the shadow region behind another collection of 5 targets/m super(3), the mean losses in echo energy for the 30 targets/m super(3) were about -0.4dB at 50kHz and about -0.2dB at 200kHz, respectively. 4. In the echograms obtained in the East China Sea, the bottom echoes fluctuated remarkably when the dense aggregations of fish appeared between transducer and seabed. Especially, in the case of the echograms of sardine school obtained in a set-net's bagnet, the disappearance of bottom echoes and the lengthening of the echo trace by fish aggregations were observed. Then the mean density of the sardine school was estimated as 36 fish/m super(3). It suggests that when the distribution density of fishes in oceans is greater than this density, the effects of fish-school attenuation and multiple scattering must be taken into account as a possible source of error in fish abundance estimates. 5. The relationship between mean backscattering strength (, dB) and target density ($\rho$, No./m super(3)) were expressed by the equations: =-46.2+13.7 Log($\rho$) at 50kHz and =-43.9+13.4 Log($\rho$) at 200kHz. 6. The difference between the experimentally derived number and the actual number of targets gradually decreased with an increase in the target density and was within 20% when the density was 30 targets/m super(3). From these results, we concluded that when the number of targets in the insonified volume is large, the validity of the echo-integration technique of estimating the density of fish schools could be expected.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.23-30
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• 2007

The ultimate objective of this study is to develop oxygen-enriched combustion techniques applicable to the system of practical industrial boiler. To this end the combustion characteristics of lab-scale LNG combustor were investigated as a first step using the method of numerical simulation by analyzing the flame characteristics and pollutant emission behaviour as a function of oxygen enrichment level. Several useful conclusions could be drawn based on this study. First of all, the increase of oxygen enrichment level instead of air caused long and thin flame called laminar flame feature. This was in good agreement with experimental results appeared in open literature and explained by the effect of the decrease of turbulent mixing due to the decrease of absolute amount of oxidizer flow rate by the absence of the nitrogen species. Further, as expected, oxygen enrichment increased the flame temperatures to a significant level together with concentrations of $CO_2$ and $H_2O$ species because of the elimination of the heat sink and dilution effects by the presence of $N_2$ inert gas. However, the increased flame temperature with $O_2$ enriched air showed the high possibility of the generation of thermal $NO_x$ if nitrogen species were present. In order to remedy the problem caused by the oxygen-enriched combustion, the appropriate amount of recirculation $CO_2$ gas was desirable to enhance the turbulent mixing and thereby flame stability and further optimum determination of operational conditions were necessary. For example, the adjustment of burner with swirl angle of $30\sim45^{\circ}$ increased the combustion efficiency of LNG fuel and simultaneously dropped the $NO_x$ formation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.195-201
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• 2014

Body fluid has been studied for diverse fields like Ringer's solutions, artificial joint fluids, cell growth culture media because it plays a crucial role in controlling body temperature and acts as a solvent for diverse metabolite processes in the body and delivery media of mineral, energy source, hormone, signal and drug from and to cell via blood or lymphatic vessel by osmotic pressure or active uptake. Stratum corneum containing extracellular lipids and NMF (natural moisturizing factor) absorbs atmospheric water residing outside of cells and utilize it to hydrate inside of their own. This process is related to skin barrier function. In this study, we conducted the cell viability test with Cell Bio Fluid $Sync^{TM}$, which mimicks body fluids including amino acids, peptides, and monosaccharides to strengthen skin barrier, and the clinical skin improvement test with cosmetics containing Cell Bio Fluid $Sync^{TM}$. In the cell viability test, HaCaT cell was treated with PBS for 3 hours, followed by the treatment of a cell culture medium (DMEM) and isotonic solution (PBS) and Cell Bio Fluid $Sync^{TM}$ for 3 hours each. Then, MTT assay and image analysis were conducted. In the clinical skin improvement test, twenty-one healthy women participated. Participants applied cosmetics containing Cell Bio Fluid $Sync^{TM}$ on their face for a week and evaluated the skin hydration, skin roughness, brightness and evenness. All measurements were conducted after they washed off their face and took a rest under the constant temperature ($22{\pm}2^{\circ}C$) and constant humidity conditions ($50{\pm}5%$) for 20 minutes. All the data were analyzed by SPSS (version 21) software program. Results showed that Cell Bio Fluid $Sync^{TM}$ improved both the cell viability and in vivo skin conditions such as skin hydration, roughness, brightness and evenness.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.130-137
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• 1999

Background: In cardiac surgery, hypothermia is associated with a number of major disadvantage, including its detrimental effects on enzymatic function, energy generation and cellular integrity. Warm cardioplegia with normothermic cardiopulmonary bypass cause three times more incidence of permanent neurologic deficits than the cold crystalloid cardioplegia with hypothermic cardiopulmonary bypass. Interruptions or inadequate distribution of warm cardioplegia may induce anaerobic metabolism and warm ischemic injury. To avoid these problems, tepid blood cardioplegia was recently introduced. Material and Method: To evaluate whether continuous tepid blood cardioplegia is beneficial in clinical practice during valvular surgery, we studied two groups of patients matched by numbers and clinical characteristics. Warm group(37$^{\circ}C$) consisted of 18 patients who underwent valvular surgery with continuous warm blood cardioplegia. Tepid group(32$^{\circ}C$) consisted of 17 patients who underwent valvular surgery with continuous tepid blood cardioplegia. Result: Heartbeat in 100% of the patients receiving continuous warm blood cardioplegia and 88.2% of the patients receiving continuous tepid blood cardioplegia converted to normal sinus rhythm spontaneously after removal of the aortic cross clamp. There were no differences between these two groups in CPB time, ACC time, the amount of crystalloid cardioplegia used and peak level of potassium. During the operation, the total amount of urine output was more in the warm group than the tepid group(2372${\pm}$243 ml versus 1535${\pm}$130 ml, p<0.01). There were no differences between the two groups in troponin T level measured 1hr and 12hrs after the operation. Conclusion: Continuous tepid blood cardioplegia is as safe and effective as continuous warm blood cardioplegia undergoing cardiac valve surgery in myocardial protection.