• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.466-475
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• 1997

I examined arbuscular mycorrhizal(AM) fungus inoculation effects on the seedling growth of Korean ash tree(Fraxinus rhynchophylla Hance), which distributes in fertile mesic soils, under a seven-day watering cycle of water stress and compost-added fertile conditions. Three Korea-native AM fungi were inoculated : an unidentified Glomus species, Gigaspora margarita Becker & Hall and Scutellospora heterogama(Nicol. & Gerd) Walker & Sanders from disturbed forest soils. The effect of AM fungus inoculation on the seedling varied depending upon fungal species and soil conditions. AM formation was 27 to 65% by the Glomus without forming spores, 47 to 74% with about 10 spores per 20g soil by G. margarita and about 65% with 35 spores by S. heterogama. The soil conditions did not affect either AM or spore formation. The Glomus inoculation increased shoot N and P concentrations, but did not affect seedling growth. G. margarita increased shoot N and P, irrespective of soil conditions, in general, but S. heterogama increased N under water stress and Pin the control soil only. These two fungi significantly increased seedling growth in both control and water stress soils. Compost addition increased the growth of non-mycorrhizal seedlings and offset AM fungus inoculation effects. The relative field mycorrhizal dependency(RFMD) of the seedlings was significant only in control and water stress soils by over 40% in G. margarita or S. heterogama AM plants. Under water stress RFMD was the most evident in S. heterogama AM plants. I conclude that some AM fungi such as G, margarita and S. heterogama can broaden the niche of Korean ash seedlings to a water stress or nutrient poor site but less likely to more fertile sites.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.657-663
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• 2014

This study was conducted to investigate the difference in feeding habits of Red-Tongued Viper Snakes, according to available foods sources and areas. The effects of differences in food sources were found on Red-Tongued Viper Snake inhabited in the Jeju Island and its islet Gapado, from May 2006 to Nov. 2010. The food sources for the Red-Tongued viper snake population in the Jeju Island were found to be as follows: Chinese red-headed centipedes (Scolopendra subspinipes mutilans), Jeju Salamanders (Hynobius quelpaertensis), Japanese tree Frogs (Hyla japonica), Narrow-mouthed Toad (Kaloula borealis), Dybowski's Brown Frogs (Rana dybowskii), Black-spotted Pond Frogs (Rana nigromaculata), Smooth Skinks (Scincella vandenburghi), Asian Keelback Snakes (Amphiesma vibakari), Lesser White-toothed Shrews (Crosidura shantungensis), Hallasan Shrews (Sorex caecutiens hallamontanus), and Jeju Striped Field Mice (Apodemus chejuensis). This implies that Red-Tongued Viper Snakes mainly feed on amphibians, reptiles, and small mammals. Among these, amphibians occupied the highest portion at 55.2% followed by mammals at 20.7%, centipedes at 13.8%, and reptiles at 10.3%. On the contrary, Red-tongued viper snake population in Gapado only feed on Chinese red-headed centipedes and Smooth Skinks (S. vandenburghi). Since only a small amount of nutrient can be obtained from Chinese red-headed centipeds or Smooth Skinks, this feeding habit for Red-tongued viper snake would adversely effect on the growth or regeneration. The reason why Red-Tongued viper snake population in the Gapado mainly feed on Lizard and Centipedes in spite of relatively various available food sources, might be due to the low density of other food sources in the Gapado. Red-Tongued viper snake could be feeding on foods that are low in quality but are easily accessible, to minimize energy consumption on searching for other more nutritious foods. A snake tends to select the size of its food depending on the size of its own head. The positive correlation was found between the size of the heads of Red-Tongued viper snakes from the Jeju island and the diameter of their foods. The head size was larger in the males than females in viper snake population from the Jeju Island, which might effect on their selection of foods. However, no significant difference was found between the sizes of the head and the food in the Red-Tongued viper snake population from the Gapado. The findings of this study would provide meaningful data, which directly shows that even within the same viper species they choose different available food sources according to their inhabitance. This leads to their growth and adaptation to their environment which is beneficial for sustaining of its population.

• Progress in Medical Physics
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• v.15 no.4
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• pp.202-209
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• 2004

Flat panel based digital radiography (DR) systems have recently become useful and important in the field of diagnostic radiology. For DRs with amorphous silicon photosensors, CsI(TI) is normally used as the scintillator, which produces visible light corresponding to the absorbed radiation energy. The visible light photons are converted into electric signal in the amorphous silicon photodiodes which constitute a two dimensional array. In order to produce good quality images, detailed behaviors of DR detectors to radiation must be studied. The relationship between air exposure and the DR outputs has been investigated in many studies. But this relationship was investigated under the condition of the fixed tube voltage. In this study, we investigated the relationship between the DR outputs and X-ray in terms of the absorbed energy in the detector rather than the air exposure using SPEC-l8, an X-ray energy spectrum model. Measured exposure was compared with calculated exposure for obtaining the inherent filtration that is a important input variable of SPEC-l8. The absorbed energy in the detector was calculated using algorithm of calculating the absorbed energy in the material and pixel values of real images under various conditions was obtained. The characteristic curve was obtained using the relationship of two parameter and the results were verified using phantoms made of water and aluminum. The pixel values of the phantom image were estimated and compared with the characteristic curve under various conditions. It was found that the relationship between the DR outputs and the absorbed energy in the detector was almost linear. In a experiment using the phantoms, the estimated pixel values agreed with the characteristic curve, although the effect of scattered photons introduced some errors. However, effect of a scattered X-ray must be studied because it was not included in the calculation algorithm. The result of this study can provide useful information about a pre-processing of digital radiography.

• Journal of dental hygiene science
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• v.18 no.4
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• pp.218-226
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• 2018

The aim of this study was to compare fluoride release and surface changes according to different orthodontic bracket adhesives the application of fluoride products. We used non-fluoridated composite resin Transbond fluoridated composite resins Blugloo and LightBond, resin-modified glass ionomer Rely $X^{TM}$ Luting 2, and conventional glass ionomer Fuji $I^{(R)}$. Fluoride release of five orthodontic bracket adhesives and fluoride release ability after application of three fluoride products (1.23% acidulated phosphate fluoride gel, Tooth Mousse $Plus^{(R)}$, Fluor Protector, and a toothbrush with sodium fluoride-containing toothpaste) were measured using a fluoride electrode that was connected to an ion analyzer. After 4 weeks of fluoride application, the surface roughness and surface morphology were examined using a surface roughness tester and field emission scanning electron microscopy. The amounts of fluoride release were observed not only on application of Tooth Mousse $Plus^{(R)}$ and Fluor Protector on resin-modified glass ionomer Rely $X^{TM}$ Luting 2 and Fuji $I^{(R)}$, but also during tooth brushing using fluoride-containing toothpaste. After application of Tooth Mousse $Plus^{(R)}$, except Transbond XT, the surface roughness increased, and all orthodontic adhesives showed a partial drop of micro-particle filler. On application of 1.23% acidulated phosphate fluoride gel on all orthodontic bracket adhesives, their surface roughness increased. To bond the orthodontic bracket, resin-modified glass ionomer Rely $X^{TM}$ Luting 2 and Fuji $I^{(R)}$ adhesives are highly recommended if the amount of fluoride release is considered to confer a preventative effect on dental caries, and among the fluoride products, Tooth Mousse $Plus^{(R)}$ and Fluor Protector are better than 1.23% acidulated phosphate fluoride gel, and these are expected to prevent dental caries even during tooth brushing with fluoride-containing toothpaste.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.635-641
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• 2003

A non-thermal pasteurization technology, high Pulsed Electric Field (PEF) has been thought to be a new alternative processing technology instead of heating. The objective of this study was to examine and compare the effect of PEF and High Temperature Short Time (HTST) treatments on the physicochemical, microbiological and sensory characteristics of citrus juices. Total sugar and titratable acidity values of fresh citrus juice and two treatments were not significantly different each other at p<0.05. The concentration of vitamin C in fresh citrus juice $(31.2{\pm}0.59\;mg%)$ was not significantly different with the value of PEF treatment $(29.4{\pm}0.75\;mg%)$ but was significantly higher than the value of HTST treatment $(27.4{\pm}0.75\;mg%)$. The color values (L, a, and b) in PEF treatment were significantly lower than the fresh citrus juice, but were higher than the values of HTST treatment. Both total bacterial cell counts $(6.65\;{\pm}\;0.08\;log_{10}(cfu/mL))$ and yeast counts $(7.79{\pm}0.07\;log_{10}(cfu/mL))$ in fresh citrus juice were significantly reduced by PEF $(1.39{\pm}0.14,\;2.42{\pm}0.1\;log_{10}(cfu/mL))$ as well as HTST treatment (0, 0). PE activity of fresh citrus juice $(1.3{\pm}0.12\;units/mL)$ was significantly reduced by PEF treatment $(0.11{\pm}0.01\;units/mL)$ and was totally inactivated by HTST treatment. Sensory evaluation scores in flavor, taste and overall acceptability between the fresh and PEF treated citrus juices $(7.2{\sim}7.5)$ were not significantly different but the values of HTST treatment $(5.1{\sim}5.8)$ were lower than others. Consequently, PEF treatment is thought to be a good alternative pasteurization method for fresh citrus juice to HTST treatment due to its strong pasteurization effect, reduced destruction of nutrients and good sensory characteristics.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.137-152
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• 2009

Present experiment was conducted at the field of Gyeongnam Agricultural Research and Extension Services in Jinju city for two continuous cropping seasons to develop several adaptable and valuable year-round forage-producing system for elevating self-sufficiency and dollar-saving by reduced importing of crude forage. Twenty cropping systems were tested in experiment using whole crop barley (WCB), oat, rye, Italian ryegrass (IRG), and triticale in winter season and com, sorghum, sorghum ${\times}$ sudangrass hybrid, and oat in summer time. Sorghum ${\times}$ sudangrass hybrid showed highest fresh forage yield among experimented summer season crops, and followed com. Com produced the most dry matter yield, and followed sorghum${\times}$sudangrass hybrid, sorghum and oat in order. There was no significant effect of former winter crops on fresh and dry matter production succeeding summer time crops. Among winter season forage crops tested, oat showed the highest fresh and dry matter when clipped on mid-May, and followed triticale, IRG, rye and WCB. Winter-time cultivated crops showed no clear effect on the growth and forage (fresh and dry matter) producing ability of following summer crops. There was the most protein content in oat plant among summer season planted crops, and in sorghum for acid detergent fiber (ADF) and in sorghum ${\times}$ sudangrass hybrid for neutral detergent fiber (NDF), respectively. While, com showed highest value of relative feed value (RFV) and total digestive nutrients (TDN) among those crops. Among winter crops, the highest crude protein was in oat plant showing no significant differences of ADF and NDF, while, relatively higher value of RFV was recognized with rye and triticale. Also, triticale contained more TDN as compare to other forage crops. The cropping combinations such as com followed by (fb) rye and maize fb triticale were regarded as promising systems having higher dry matter producing ability among tested combinations. Considering TDN producing potential, the combinations with sorghum ${\times}$ sudangrass hybrid fb triticale andlor rye were would be suitable ones, coincidently. There was a tendency which elevating pH, electric conductivity (EC) and organic matter (OM) contents in soil after experiment comparing to before planting. More crude protein content in plant was shown at mid-May clipping as compared to the forage at April cut in all winter season grown crops. ADF and NDF contents were increased by delayed clipping showing decreased tendency of RFV and TDN in plant. In conclusion, many cropping systems would be available using above mentioned forage crops according to farmer's conditions and scale, etc.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.367-370
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• 2007

To make the soil moisture proper is the important factor in the seedbed cultivation of Yangjik for producing a good quality of ginseng seedling. This study was carries out to investigate the effect of soil moisture on photosynthesis and yield of ginseng seedling under the different condition of the soil moisture, such as $100{\sim}400$ mbar. Photosynthesis rate was decreased gradually by the reduction of soil moisture, and in particular it was decreased distinctly under the lower condition of soil moisture, such as $300{\sim}400$ mbar. Photosynthesis rate in air temperature of $30^{\circ}C$ was decreased more distinct than that of $25^{\circ}C$, Light saturation point of leaves was at the quantum of $600{\mu}mol/m^3/s$ at $25^{\circ}C$ while it was decreased by $300{\mu}mol/m^3/s$ at $30^{\circ}C$ according to the increase of air temperature. Respiration rate was increased by the increase of quantum, and decreased by the reduction of soil moisture. Respiration rate under the condition of high quantum was increased regardless of air temperature, but it was decreased distinctly under the condition of low soil moisture and high air temperature, such as 400 mbar at $30^{\circ}C$. There were a gradual decrease by the reduction of soil moisture in leaf length, leaf width, chlorophyll content, and water content of leaves, but heat injury ratio was increased distinctly by the reduction of it. Total root weight, root weight per plant, the yield of usable seedling were decreased by the reduction of soil moisture, and optimal content of soil moisture to produce a good quality of seedling was 63% of field capacity or 18.9% in absolute soil moisture content.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.783-789
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• 2011

Recently, auto-thermal thermophilic aerobic digestion (ATAD) has a great attention for destruction of wasted sludge biomass in wastewater treatment plant. Reduction of sludge concentration has been successfully achieved with pilot scale ATAD and ceramic filtration process in field condition. However, high concentration of COD, total nitrogen (TN) and total phosphorus (TP) was observed in filtrate, which should be treated before recirculation of filtrate to biological wastewater treatment plant. This study was focused on removal of nitrogen and phosphorus contained in the filtrate of ATAD, using struvite crystallization method. The effect of operational and environmental parameters (such as, N, P and Mg ion concentration and molar ratio, pH, reaction time, agitation strength, seed dosage, and reaction temperature) on the treatment of TN and TP with struvite crystallization were evaluated. Magnesium (as $MgCl_26H_2O$) and phosphorus (as $K_2HPO_4$) ions were, if necessary, added to increase nitrogen removal efficiency by the crystal formation. Average concentration of $NH_4^+-N$ and $PO_4^{3-}-P$ of the filtrate were 1716.5 mg/L and 325.5 mg/L, respectively. Relationship between removal efficiencies of nitrogen and phosphorus and molar ratios of $Mg^{2+}$ and $PO_4^{3-}-P$ to $NH_4^+-N$ was examined. Crystal formation and nitrogen removal efficiencies were significantly increased as increasing molar ratios of magnesium and phosphorus to nitrogen. As molar ratio of $Mg^{2+}:PO_4^{3-}-P:NH_4^+-N$ were maintained to 2 : 1 : 1 and 2 : 2 : 1, removal efficiencies of nitrogen and phosphorus were 71.6% and 99.9%, and 93.8% and 98.6%, respectively. However, the effect of reaction time, mixing intensity, seed dose and temperature on the struvite crystallization reaction was not significant, comparing to those of molar ratios. Settled sludge volume after struvite crystallization was observed to be reduced with increase of seed dose and to be increased at high temperature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2358-2370
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• 2010

This research aims to empirically analyze the factors that affect the success of technology marketing by Korean universities. The total of 207 universities which successfully made technology transfers from 2006 to 2008 was examined to test the nine hypotheses. For the purpose of testing the hypotheses, technology infrastructure (research costs and the number of SCIE papers), the compensation system for the patents (application and registration), the number of patents (application and registration), TLO staff (the number of people in charge of technology transfer and the job experience in industries), the compensation system for technology transfers (researchers and contributors), and attitudes of university management and industries were analyzed with structural equation methods to figure out their effects on the revenues of technology transfer. The results of this research are summarized as follows. First, technology infrastructures of universities were found to have positive effects on securing patents. As the university research costs in the field of science and technology are increases, the research capabilities are enhanced and this a larger number of researchers are conducted. Second, this research shows that compensation systems for patent application and registration in universities have motivated researchers to take out patents for the outputs of their research. Third, the number of patents universities possess was found to have a positive effect on technology transfer. An increase in the number of patents universities possess implies an increase in the diversity and excellence of the target technologies for transfer. Fourth, the number of patents universities possess turned out to have a positive effect on TLO staff. The number of experts in charge of technology transfer including technology dealers, valuation analysis and patent attorneys should be increased as target technologies for transfer increase according to the increase of patents possessed. Because the technologies are transferee from universities to businesses, businesses (job) experience of TLO staff in industries are also important. This research is meaningful because it has identified the factors affecting the results of technology transfer by employing structural equation methods. In particular, an official governmental survey data for the academic-industrial cooperation were analyzed systematically in terms of technology infrastructure, compensation systems related to patents, the number of patents, TLO staff, compensation systems for technology transfer, and attitudes of university management and industries. All these facts might could differentiate this study from the previous studies.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.92-99
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• 2000

To compare the effect of food waste compost(FWC) application on the sodicity of paddy and upland soil, laboratory experiment was conducted. Six kinds of FWC made of various mixing ratio of food waste and pig slurry as raw material were applied to paddy soil under submerged condition and to upland soil in field water capacity, and were kept at $25^{\circ}C$ under laboratory incubation. The higher the mixing ratio of food waste on making FWC, the higher the FWC showed Na content and EC. Mineralized ratio of cations in FWC during incubation showed no difference between paddy and upland soil. It was high in the order of Na>K>Mg>Ca as 99, 94, 71, and 71%, respectively. NaCl contents of FWC applied to soils against SAR and ESP were fitted well to first linear regression with extremely high significance($R^2=0.99$). Increasing rate of SAR and ESP was higher in upland soil than paddy soil by 2.3 times. The difference was considered to be caused by dilution effect which was exerted by the application of more soil to water ratio to paddy soil than to upland soil on SAR analysis in consideration of cultivating condition. The calculated values of $([Ca^{2+}+Mg^{2+}]/2)^{1/2}$ used as a denominator on SAR calculation showed a little difference among FWC treatments by 2.1~2.4, while [$Na^+$] used as a numerator showed much variance by 3.1~9.5. Therefore, as a parameter for the assessment of FWC quality affecting soil sodicity, the use of only Na content in FWC was proposed without regarding Ca and Mg contents. Soil Ex. Na contents showed extremely high correlation($R^2=0.99$) with ESP. Moreover, because the former can be more easily determined than the latter, soil Ex. Na content was proposed as a new sodicity index.