• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.100-101
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• 2012

The plasma damage free and room temperature processedthin film deposition technology is essential for realization of various next generation organic microelectronic devices such as flexible AMOLED display, flexible OLED lighting, and organic photovoltaic cells because characteristics of fragile organic materials in the plasma process and low glass transition temperatures (Tg) of polymer substrate. In case of directly deposition of metal oxide thin films (including transparent conductive oxide (TCO) and amorphous oxide semiconductor (AOS)) on the organic layers, plasma damages against to the organic materials is fatal. This damage is believed to be originated mainly from high energy energetic particles during the sputtering process such as negative oxygen ions, reflected neutrals by reflection of plasma background gas at the target surface, sputtered atoms, bulk plasma ions, and secondary electrons. To solve this problem, we developed the NBAS (Neutral Beam Assisted Sputtering) process as a plasma damage free and room temperature processed sputtering technology. As a result, electro-optical properties of NBAS processed ITO thin film showed resistivity of $4.0{\times}10^{-4}{\Omega}{\cdot}m$ and high transmittance (>90% at 550 nm) with nano- crystalline structure at room temperature process. Furthermore, in the experiment result of directly deposition of TCO top anode on the inverted structure OLED cell, it is verified that NBAS TCO deposition process does not damages to the underlying organic layers. In case of deposition of transparent conductive oxide (TCO) thin film on the plastic polymer substrate, the room temperature processed sputtering coating of high quality TCO thin film is required. During the sputtering process with higher density plasma, the energetic particles contribute self supplying of activation & crystallization energy without any additional heating and post-annealing and forminga high quality TCO thin film. However, negative oxygen ions which generated from sputteringtarget surface by electron attachment are accelerated to high energy by induced cathode self-bias. Thus the high energy negative oxygen ions can lead to critical physical bombardment damages to forming oxide thin film and this effect does not recover in room temperature process without post thermal annealing. To salve the inherent limitation of plasma sputtering, we have been developed the Magnetic Field Shielded Sputtering (MFSS) process as the high quality oxide thin film deposition process at room temperature. The MFSS process is effectively eliminate or suppress the negative oxygen ions bombardment damage by the plasma limiter which composed permanent magnet array. As a result, electro-optical properties of MFSS processed ITO thin film (resistivity $3.9{\times}10^{-4}{\Omega}{\cdot}cm$, transmittance 95% at 550 nm) have approachedthose of a high temperature DC magnetron sputtering (DMS) ITO thin film were. Also, AOS (a-IGZO) TFTs fabricated by MFSS process without higher temperature post annealing showed very comparable electrical performance with those by DMS process with $400^{\circ}C$ post annealing. They are important to note that the bombardment of a negative oxygen ion which is accelerated by dc self-bias during rf sputtering could degrade the electrical performance of ITO electrodes and a-IGZO TFTs. Finally, we found that reduction of damage from the high energy negative oxygen ions bombardment drives improvement of crystalline structure in the ITO thin film and suppression of the sub-gab states in a-IGZO semiconductor thin film. For realization of organic flexible electronic devices based on plastic substrates, gas barrier coatings are required to prevent the permeation of water and oxygen because organic materials are highly susceptible to water and oxygen. In particular, high efficiency flexible AMOLEDs needs an extremely low water vapor transition rate (WVTR) of $1{\times}10^{-6}gm^{-2}day^{-1}$. The key factor in high quality inorganic gas barrier formation for achieving the very low WVTR required (under ${\sim}10^{-6}gm^{-2}day^{-1}$) is the suppression of nano-sized defect sites and gas diffusion pathways among the grain boundaries. For formation of high quality single inorganic gas barrier layer, we developed high density nano-structured Al2O3 single gas barrier layer usinga NBAS process. The NBAS process can continuously change crystalline structures from an amorphous phase to a nano- crystalline phase with various grain sizes in a single inorganic thin film. As a result, the water vapor transmission rates (WVTR) of the NBAS processed $Al_2O_3$ gas barrier film have improved order of magnitude compared with that of conventional $Al_2O_3$ layers made by the RF magnetron sputteringprocess under the same sputtering conditions; the WVTR of the NBAS processed $Al_2O_3$ gas barrier film was about $5{\times}10^{-6}g/m^2/day$ by just single layer.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.343-350
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• 2007

Three different experiments were carried out to investigate the runoff and erosion losses of endosulfan from sloped-field by rainfall. The mobility of endosulfan and which phase it was transported by were examined in adsorption study, the influence of rainfall pattern and slope degree on the pesticide loss were evaluated in simulated rainfall study, and the pesticide losses from soybean-grown field comparing with bare soil were measured in field lysimeter study. Adsorption parameter (K) of endosulfan ranged from 77 to 131 by adsorption method and K values by the desorption method were higher than those by the adsorption method. By the SSLRC's classification for pesticide mobility endosulfan was classified as non-mobile class ($K_{oc}>4,000$). Runoff and erosion loss of endosulfan by three rainfall scenarios ranged from 3.4 to 5.6%and from 4.4 to 15.6%of the amount treated. Endosulfan residues were mainly remained at the top 5 cm of soil depth after the simulated rainfall study. Pesticide loss in case of 30%-slope degree ranged from 0.6 to 0.9 times higher than those in case of 10%-slope degree. The difference of pesticide runoff loss was related with its concentration in runoff water and the difference of pesticide erosion loss would related closely with the quantity of soil eroded. Endosulfan losses from a series of lysimeter plots in sloped land by rainfall ranged from 5 to 35% of the amount treated. The erosion rate of endosulfan from soybean-plots was 66% of that from bare soil plots. The effect of slope conditions was not great for runoff loss, but was great for erosion loss as increasing to maximum $4{\sim}12$ times with slope degree and slope length. The peak runoff concentration of endosulfan in soybean-plots and bare soil plots ranged from 8 to 10 and from 7 to $9{\mu}gL^{-1}$ on nine plots with different slope degree and slope length. Therefore the difference of the peak runoff concentrations between bare soil plots and soybean-plots were not great.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.230-240
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• 2017

BACKGROUND: To evaluate residues of environmentally concerned pesticides in water system, this monitoring was conducted over three rivers. The residual characteristics and discharging condition of these residues on water system was investigated. METHODS AND RESULTS: Total twenty nine sampling sites were selected through main streams and branch streams of Keum, Mangyung and Dongjin rivers, and the water samples from them were regularly collected one month interval, especially biweekly from May to August in 2002. Of the pesticides monitored, six fungicides which include hexaconazole, isoprothiolane and iprobenfos were detected with frequencies of 0.3-50.9% and in their residue level of $0.1-4.7{\mu}g/L$. Sixteen insecticides which include nine organophosphoruses, three carbamates, endosulfan, cypermethrin, buprofezin and fipronil were detected with frequencies of 0.3-32.5% and in their residue level of $0.01-2.8{\mu}g/L$. Nine herbicides which include alachlor molinate, anilofos, butachlor, dimepiperate, metolachlor, oxadiazon, pretilachlor and thiobencarb were detected with frequencies of 0.8-22.9% and in their residue level of $0.01-9.07{\mu}g/L$. CONCLUSION: Detection frequencies and residue levels of insecticides and herbicides were the highest in waters sampled in May and June. Almost pesticides detected were for the paddy rice and their residue levels were very low to compare with standard values.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.281-292
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• 2004

This pot experiment was conducted to investigate the effects of systematic variation appling of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover, The treatments of systematic variation were 0/100. 25/75, 50/50. 75/25, and $100/0\%$ in the Fe/Cu, Mn/Zn, and Fe+Cu/Mn+Zn trials, respectively. The treatments of Fe/Mn/Cu/Zn trial were $70\%$ in main-element and $10\%$ in other 3sub-elements. 1 . General differences had been showed in the relative contents, uptake amounts, and mutual ratios of Fe, Mn, Cu, and Zn between orchardgrass and white clover. The effects of Fe application on the all traits were generally insignificant. The Mn and Cu applications, however, showed consistent differences in the all traits. At the high relative content of Mn in the forages influenced by the Mn application, the relative contents of Fe, Cu and Zn were greatly decreased without the significant differences in common content. 2. The increase of uptake amount of each micronutrient was not positively correspond to the yield increase. In some cases, the uptake amount of micronutrient was greatly increased without the significant increase of yield. At the Mn application, the Mn uptake amount was relatively much more increased than increase of the yield. The uptake amount of each element was significantly increased by the application with Mn and Cu. However, it was not in the case of Fe and Zn. 3. The mutual ratios of micronutrients were more influenced by the applications of Mn and Cu, especially Mn, than those by the applications of Fe and Zn. In the Fe/cu trial, the ratios of Fe/Cu showed 6.0~ 10.5 in orchardgrass and 10.2~ $16.4\%$ level of difference in white clover. In the Fe+Cu/Mn+Zn trial, the ratios of Mn/Cu, Mn/Zn, and Fe/Mn were greatly influenced by the treatments. It has been also found that the poor growth of white clover was caused by the unbalanced ratios of Fe/Mn, and it tended to be enhanced by the good applications and mutual ratios of other elements.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.841-848
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• 2003

The sensory characteristics of red wine Gerbong (G), Campbell (C), Moru (M), Gerbong ＋ Moru (70 : 30, GM), Gerbong + Campbell (70 : 30, GC) and French wine (F, Carbernet Sauvignon, 1998) were evaluated. The preferences of color, flavor, taste and total evaluation were determined by a ranking test, and the organoleptic characteristics were evaluated by a quantitative descriptive analysis (QDA) method. The mean color scores of C, GM, F, GC, M and G were 4.74, 3.94, 4.67, 3.70, 2.65 and 1.47, respectively (p<0.001). The order for the mean score for flavor was GM (4.12) = M (3.94) = C (3.76) = F (3.76) ${\geq}$ GC (3.12)>G (2.29) (p<0.01), and the order for taste was F (4.75) ${\geq}$ C (4.25) ${\geq}$ GM (3.37) = GC (3.50) ${\geq}$ G (2.75) = M (2.37) (p<0.001). The total evaluation of mean scores showed G, M, C, GM, GC and F were 237, 2.44, 4.06, 3.87, 3.64 and 4.81, respectively (p<0.001). Influences of sensory characteristics on the total evaluation, in percentages, were 69.3% for taste, 3.7% for color, and 1.5% for flavor. The influences of taste, color, and flavor in red wine were 17% for sweet, acid, bitter and salty taste, 28.9% for purple and red color, and 14.4% for grape flavor. The attributes of the purple and red colors showed a positive correlation with grape flavor, oak flavor, grape taste, and floral tastes, but a negative correlation with $SO_2$, flavor. The attribute of sweet taste showed a positive correlation with grape flavorand floral flavor, but a negative correlation with bitter and astringency tastes, according to Pearsons correlation analysis (p<0.01).

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.327-357
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• 2011

This study compared the species composition and distribution of the forest communities between Korea and Japan using vegetation releve database. The study included the eastern and southern Korean Peninsula, Is. Jeju, Is. Ulreung, northern Kyushu, central part of Japan and Is. Tsushima and divided in fourteen region with major mountain as the center. Seventy-nine forest communities were classified by tabular comparison with the total of 1844 releves. In the composition table, fifty-four groups of plant species were listed. Some grew in one area exclusively, while others were present in multiple locations. This study showed the similarity and heterogeneity of species composition among study areas. We grouped fourteen types showing similar physiognomy for forest communities. The physiognomical features of the vertical vegetation zones in the study area were similar, however, dominant species and species composition were different between the regions. In the lowland zone, Castanopsis-Type dominated by Castanopsis cuspidata var. sieboldii or Castanopsis cuspidata were distributed in the study area except for northern part of the Korean Peninsula and Is. Ulreung. Additionally, Persea thunbergii-Type was distributed widely in the lowest part of the study area, however, it showed the simplification of the species composition in the Korean Peninsula and Is. Ulreung. In the hilly zone, evergreen forest composed by Abies firma-Type distributed in northern Kyushuand Is. Tsushima, but it was absent in the other study region. The difference in forest community was conspicuous, especially in the montane zone. Deciduous broadleaved forests composed Quercus(D)-Type and Fagus-Type widely distributed in the montane of study area. However, forest community dominated by Quercus mongolica and Fagus multinervis flourished in Korea. On the otherhand, forest community dominated by Quercus mongolica var. grosseserrata, Fagus crenata and F. japonica distributed in Japan. In the sub-alpine zone, evergreen coniferous forest composed Abies-Quercus(D)-Type, Abies koreana-Type, and Pinus pumila-Type were distributed in the Korean Peninsula and Is. Jeju. Forests composed Taxus cuspidata var. nana-Type, Abies mariesii-Type, and Pinus pumila-Type distributed in the central part of Japan. As a result of DCA ordination, evergreen broadleaved forests of the whole study area showed the lower scores along the first axis, while deciduous and coniferous forests showed the higher scores. The forest types of western part of Japan were located the higer scores, forest types of the Korean Peninsula were located the lower scores, and forest types of Is. Jeju located in the middle. Warmth index (WI) and Annual range of temperature in climate factor were highly correlated on the first axis. The first axis reflected the gradient from oceanic climatic to continental one. The higher the altitude and further geographically, the lower the similarity among communities and the peculiarity of community appeared stronger. The historical background reflecting local flora has strongly influenced on development of community.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.70-80
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• 2005

To evaluate the exposure of molinate in agricultural environment and its effect against the non-target crop in air, this experiment was conducted to elucidate volatilization characteristics of molinate in aquatic condition and to determine critical concentration of molinate in the air causing phytotoxicity to Chili pepper. Cumulative volatilized rate of molinate from water was 22.7% at $35^{\circ}C$ for water temperature and 20 L/min for air velocity while 3.2% at $25^{\circ}C$ and 10 L/min within 47 hour after applied under closed system, respectively. The molinate concentrations in air above 60 cm height from soil surface of valley and open paddy rice field were reached the highest value of 18.17 and $11.59{\mu}g/m^3$, respectively within 24 hours after applying granular formulation at dose rate of molinate 150 g/1,000 $m^2$. However, their concentrations were drastically diminished to around 0.18 and $0.51{\mu}g/m^3$ level in 20 days after application, which volatilization pattern were similar to both regions. Also, the concentration of molinate in air above 60 cm height from soil surface was distributed higher 2 times than that above 180 cm height. Meanwhile, a phytotoxic symptom against the nearby chili pepper was revealed within three days after applied and molinate was detected $0.004{\sim}0.006$ mg/kg level from severe damaged leaves. The dose and exposure relations of molinate in the air against the non-target crop was also investigated in lab trial. The phytotoxic symptom, shriveled leaves, of the chili pepper was encountered by exposing two days with concentration of $13.6{\mu}g/m^3$, three days with $6.8{\mu}g/m^3$ or four days with $3.4{\mu}g/m^3$. The symptom was still recovered within four weeks after the plants had received fresh air. On the other hand, the phytotoxic response through root uptake of the herbicide in water culture was relatively insensitive, in which the symptom is observed ten days with the concentration of 300 ${\mu}g/L$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1343-1348
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• 2006

This study was performed to investigate the effects of silk protein enzyme hydrolysates on blood glucose and serum lipid in db/db diabetic mice. Twelve week-old-male C57BL/KsJ db/db mice were divided into two groups: diabetic control group and 0.25% silk protein hydrolysates solution group, which were fed for 8 weeks. Body weight increased in the silk protein hydrolysates group compared with the diabetic control group. There were no differences in food and water intake between the diabetic control and the silk protein hydrolysates groups. The weight of liver increased in the silk protein hydrolysates group while that of kidney increased in the diabetic control group. The blood glucose level increased about 18.0% in the diabetic control group after 8 weeks while that in the silk protein hydrolysates group increased about 5.8%. Also, silk protein hydrolysates improved the glucose tolerance in C57BL/KsJ db/db mice. There was no difference in total cholesterol and non-HDL cholesterol concentration between the diabetic control and the silk protein hydrolysates group. Triglyceride concentration were lower in the silk protein hydrolysates group than in the diabetic control group (p<0.05) while HDL-cholesterol concentration were higher in the silk protein hydrolysates group than in the diabetic control group (p<0.05). This results suggest that administration of silk protein enzyme hydrolysates reduces significantly an increasing rate of 1]food glucose, decreases triglyceride, and increases HDL-cholesterol in C57BL/KsJ db/db mice.

• Journal of agricultural medicine and community health
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• v.28 no.1
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• pp.29-37
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• 2003

Objectives: This study was performed to evaluate the pesticide exposure status and acute pesticide poisoning symtoms among agricultural workers at Gangwon-do province alpine area. Alpine area was defined as the area higher than 400m. Methods: We analyzed 257 interviwed questionnaire about pesticide exposure, acute pesticide poisoning symptoms and other variables. Results: The result was shown that agricultural workers at alpine area used more pesticide than general agricultural workers for annual usage days(35.9 days vs 14.4 days), daily usage hours(6.7 hrs vs 2.8hrs, p<0.05). But there was no difference between general and alpine agricultural worker's herbicide exposure. Moreover, the alpine agricultural worker's acute pesticide poisoning symtom score was higher than general agricultural worker's. These difference was also found at result of regression analysis, under control the age, sex, monthly income. Most frequently suffered symptom was headache and dermatological problems. The symptom prevalence of dermatological problem, headache, general weakness, eye irritation, nausea were higher among alpine agricultural workers than general agricultural workers. Conclusions: As a result, agricultural workers at alpine area were more exposed to pesticide and suffered from pesticide poisoning symptoms. To prevent the symptoms and disease from pesticide exposure among agricultural workers at alpine area, more research and political effort will be needed.

• Journal of the Korea Concrete Institute
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• v.14 no.1
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• pp.126-135
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• 2002

Plate bonding technique has been widely used in strengthening of existing concrete structures, although it has often a serious problem of premature falure such as interface separation and rip-off. However, this premature failure problem has not been well explored yet especially in view of local failure mechanism around the interface of plate ends. The purpose of the present study is, therefore, to identify the local failure of strengthened plates and to derive a separation criterion at the interface of plates. To this end, a comprehensive experimental program has been set up. The double lap pull-out tests considering pure shear force and half beam tests considering combined flexure-shear force were performed. The main experimental parameters include plate thickness, adhesive thickness, and plate end arrangement. The strains along the longitudinal direction of steel plates have been measured and the shear stress were calculated from those measures strains. The effects of plate thickness, bonded length, and plate end treatment have been also clarified from the present test results. Nonlinear finite element analysis has been performed and compared with test results. The Interface properties are also modeled to present the separation failure behavior of strengthened members. The cracking patterns as well as maximum failure loads agree well with test data. The relation between maximum shear and normal stresses at the interface has been derived to propose a separation failure criterion of strengthened members. The present study allows more realistic analysis and design of externally strengthened flexural member with steel plates.