• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.2
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• pp.95-107
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• 2020

The purpose of this study is to provide the basic data by analyzing and analysing the Growth Conditions of old Trees in Yangdong village. This study investigated about the conducted on tree information, soil information, and tree health. The result are as follows. The trees information in Yangdong Village consists of Juniperus chinensis, Salix chaenomeloides, Salix pseudolasiogyne, Celtis sinensis, Zelkova serrata, Gleditsia japonica, and Gleditsia sinensis trees, The range of height was 4.0~17.0m, and the diameter was 0.51~1.34m, Juniperus chinensis trees of No.17 was most large. In the results of soil analysis, there showed that acidity was pH4.1~6.3, hardness of 5~48mm, organic matter content of 21.2~29.1g/kg, electrical conductivity(EC) of 0.34~1.76dS/m, available P₂O₅ of 79.8~451.6mg/kg, exchangeable K of 0.22~1.71cmol+/kg, exchangeable Ca of 4.98~7.44cmol+/kg, exchangeable Mg of 0.67~2.19cmol+/kg, exchangeable Na of 0.19~1.04cmol+/kg and cation exchange capacity(C.E.C) of 7.23~13.02cmol+/kg. As a result, the highest number of tree health levels is 8 of 11trees of Celtis sinensis, 2 of 7trees of Zelkova serrata, and 3 of Gleditsia sinensis, and 13 of 30 trees of health levels, The Older trees with high infection, spoil and hollowed part were the remaining trees except for the healthy part. Relatively, more than half of the number of targets is infected, decay, and the hollowed site, and it is necessary to perform surgery on the damaged area. In addition, preservation and protection measures should be implemented by supplying root nutrients for trees, controlling nutrients in the body to prevent secondary and tertiary damages that cause the infection site to metastasize to the health site, In order to continually monitor the trees, measures to improve the location environment and management of the trees should be sought.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.11a
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• pp.3-4
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• 2000

Many researchers are interested in the synthesis and characterization of carbon nitride and diamond-like carbon (DLq because they show excellent mechanical properties such as low friction and high wear resistance and excellent electrical properties such as controllable electical resistivity and good field electron emission. We have deposited amorphous carbon nitride (a-C:N) thin films and DLC thin films by shielded arc ion plating (SAIP) and evaluated the structural and tribological properties. The application of appropriate negative bias on substrates is effective to increase the film hardness and wear resistance. This paper reports on the deposition and tribological OLC films in relation to the substrate bias voltage (Vs). films are compared with those of the OLC films. A high purity sintered graphite target was mounted on a cathode as a carbon source. Nitrogen or argon was introduced into a deposition chamber through each mass flow controller. After the initiation of an arc plasma at 60 A and 1 Pa, the target surface was heated and evaporated by the plasma. Carbon atoms and clusters evaporated from the target were ionized partially and reacted with activated nitrogen species, and a carbon nitride film was deposited onto a Si (100) substrate when we used nitrogen as a reactant gas. The surface of the growing film also reacted with activated nitrogen species. Carbon macropartic1es (0.1 -100 maicro-m) evaporated from the target at the same time were not ionized and did not react fully with nitrogen species. These macroparticles interfered with the formation of the carbon nitride film. Therefore we set a shielding plate made of stainless steel between the target and the substrate to trap the macropartic1es. This shielding method is very effective to prepare smooth a-CN films. We, therefore, call this method "shielded arc ion plating (SAIP)". For the deposition of DLC films we used argon instead of nitrogen. Films of about 150 nm in thickness were deposited onto Si substrates. Their structures, chemical compositions and chemical bonding states were analyzed by using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and infrared spectroscopy. Hardness of the films was measured with a nanointender interfaced with an atomic force microscope (AFM). A Berkovich-type diamond tip whose radius was less than 100 nm was used for the measurement. A force-displacement curve of each film was measured at a peak load force of 250 maicro-N. Load, hold and unload times for each indentation were 2.5, 0 and 2.5 s, respectively. Hardness of each film was determined from five force-displacement curves. Wear resistance of the films was analyzed as follows. First, each film surface was scanned with the diamond tip at a constant load force of 20 maicro-N. The tip scanning was repeated 30 times in a 1 urn-square region with 512 lines at a scanning rate of 2 um/ s. After this tip-scanning, the film surface was observed in the AFM mode at a constant force of 5 maicro-N with the same Berkovich-type tip. The hardness of a-CN films was less dependent on Vs. The hardness of the film deposited at Vs=O V in a nitrogen plasma was about 10 GPa and almost similar to that of Si. It slightly increased to 12 - 15 GPa when a bias voltage of -100 - -500 V was applied to the substrate with showing its maximum at Vs=-300 V. The film deposited at Vs=O V was least wear resistant which was consistent with its lowest hardness. The biased films became more wear resistant. Particularly the film deposited at Vs=-300 V showed remarkable wear resistance. Its wear depth was too shallow to be measured with AFM. On the other hand, the DLC film, deposited at Vs=-l00 V in an argon plasma, whose hardness was 35 GPa was obviously worn under the same wear test conditions. The a-C:N films show higher wear resistance than DLC films and are useful for wear resistant coatings on various mechanical and electronic parts.nic parts.

• The Korean Journal of Physiology
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• v.20 no.1
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• pp.17-29
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• 1986

The present study was carried out to observe the effect of triiodothyronine on heart, one of the target organ of thyroid hormone. There are many reports that tachycardia, arrythmia, and agumentation of sodium, potassium pump activity are caused in hyperthyroid animal. To examine these cardiac positive chronotropic effects on sinoatrial (SA) node and atrial muscle, hyperthyroid state was induced experimentally by the injecion of 3,3',5-1-triiodothyronine $(T_3)$ in $3{\sim}6$ month-old rabbits. Then intracellular recordings by inserting glass microelectrode into cell were obtained in SA node and atrial muscle. The results can be summarized as follows : 1) Heartbeat was increased from $169.6{\pm}28.0\;to\;264.2{\pm}18.0$ beats per minute, while body weight was decreased to 68f of the initial body weight (Day 1). 2) In experimental group, the duration of action potential at 80% repolarization was decreased from $148.0{\pm}29.1\;to\;107{\pm}13.6msec$. This suggested the increase heartbeat. 3) The firing rate in hyperthyroid group markedly reduced under the 15 mM potassium Tyrode (p<0.005). 4) In hyperthyroid group, depolarization of atrial muscle cell was lowered significantly in 15 mM (p<0.05), 20 mM (p<0.05) potassium Tyrode solution. 5) Sodium-potassium pump activities in experimental group were higher than those in control group in both SA node (p<0. 1) and atrial muscle (p<0.025). 6) In lower concentration of $MnCl_2$, the excitability of SA node in hyperthyroid group was decreased more than that in control group. Effective inhibitory dose $(ID_{50})$ as 0.6 mM in hyperthyroid statd and 1.1 mM in control group.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.411-427
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• 2006

This study aimed to recognize characteristics of groundwater flow in fractured bedrocks based on zonal pump-ing tests, slug tests, water quality logs and borehole TV camera logs conducted on two boreholes (NJ-11 and SJ-8) in the city of Naju. Especially, the zonal pumping tests using sin91e Packer were executed to reveal groundwater flow characteristics in the fractured bedrocks with depth. On borehole NJ-11, the zonal pumping tests resulted in a flow dimension of 1.6 with a packer depth of 56.9 meters. It also resulted in lower flow dimensions as moving to shallower packer depths, reaching a flow dimension of 1 at a 24 meter packer depth. This fact indicates that uniform permissive fractures take place in deeper zones at the borehole. On borehole SJ-8, a flow dimension of 1.7 was determined at the deepest packer level (50 m). Next, a dimension of 1.8 was obtained at 32 meters of packer depth, and lastly a dimension of 1.4 at 19 meters of packer depth. The variation of flow dimension with different packer depths is interpreted by the variability of permissive fractures with depth. Zonal pumping tests led to the utilization of the Moench (1984) dual-porosity model because hydraulic characteristics in the test holes were most suitable to the fractured bedrocks. Water quality logs displayed a tendency to increase geothermal temperature, to increase pH and to decrease dissolved oxygen. In addition, there was an increasing tendency towards electrical conductance and a decreasing tendency towards dissolved oxygen at most fracture zones.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.533-545
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• 2015

Spatial and seasonal variations in hydrogeochemical characteristics and the factors affecting the deterioration in quality of shallow portable groundwater in an agricultural area are examined. The aquifer consists of (from the surface to depth) agricultural soil, weathered soil, weathered rock, and bedrock. The geochemical signatures of the shallow groundwater are mostly affected by the NO₃⁻ and Cl⁻ contaminants that show a gradual downward increase in concentration from the upper area, due to the irregular distribution of contamination sources. The concentrations of the major cations do not varied with the elapsed time and the NO₃⁻ and Cl⁻ ions, when compared with concentrations in background groundwater, increase gradually with the distance from the upper area. This result suggests that the water quality in shallow groundwater deteriorates due to contaminant sources at the surface. The contaminations of the major contaminants in groundwater show a positive linear relationship with electrical conductivity, indicating the deterioration in water quality is related to the effects of the contaminants. The relationships between contaminant concentrations, as inferred from the ternary plots, show the contaminant concentrations in organic fertilizer are positively related to concentrations of NO₃⁻, Cl⁻, and SO₄²⁻ ions in the shallow portable groundwaters, which means the fertilizer is the main contaminant source. The results also show that the deterioration in shallow groundwater quality is caused mainly by NO₃⁻ and Cl⁻ derived from organic fertilizer with additional SO₄²⁻ contaminant from livestock wastes. Even though the concentrations of the contaminants within the shallow groundwaters and the contaminant sources are largely variable, it is useful to consider the ratio of contaminant concentrations and the relationship between contaminants in groundwater samples and in the contaminant source when analyzing deterioration in water quality.

• Economic and Environmental Geology
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• v.47 no.6
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• pp.611-623
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• 2014

The alluvial aquifer, widely developed near the four major rivers such as Nakdong River, can be used effectively for groundwater artificial recharge and is expected to be the future water resources in Korea. This study is aimed at examining the impact of repeatedly injected river water into the riverside alluvial aquifer on injection rate or efficiency in its system at Changweon area. For this, injection tests were performed two times, first on June 19 and second on September 25 through October 9, 2013, and the mixing ratios of river water to groundwater were used as the tool to compare the efficiency of injection. The mixing ratios were evaluated by using electrical conductivities of injected river water (average $EC=303{\mu}S/cm$) and groundwater ($EC{\fallingdotseq}6,000{\mu}S/cm$) measured at 20 m depth of four observation wells installed 10 m apart from each injection well. The result shows the remarkable differences on two respects. First, in some observation well, detection time for incipient injection effect during $2^{nd}$ injection test was shown to be much slower than that of $1^{st}$ injection test. Second, the hourly increasing rate of mixing ratios in $2^{nd}$ test was revealed to be reduced much more than that of $1^{st}$ test. This means that the efficiency of injection was badly deteriorated by only 1,210 minute injection work. Therefore, injection water needs to be adequately treated beforehand and repeated pumping work and/or resting phase is needed afterwards. To a certain extent, the improvement of water quality in saline aquifer was verified in this system by injection tests.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.394-398
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• 1997

Changes of nutrient material and heavy metals of irrigation water and natural supplies by irrigation water into 1.0ha of paddy field during the rice cultivation was investigated pH of irrigation water ranged 6.458.34 and electrical conductivity showed $110{\mu}S/cm$ in the first irrigation period and commonly showed $90{\mu}S/cm$. The content of T-N, NH4-N and $NO_3-N$were 3.09~12.36, 0.17~1.34 and 2.70~10.72mg/L respectively. The content of T-P was 0.09~0.22mg/L and ortho-P was not detected. The content of $Ca^{++},\;Mg^{++},\;Na^+\;and\;K^+$ showed 0.89~5.12, 1.12~2.76, 1.74~4.52 and 1.34~4.18mg/L regardless of irrigation season respectively. Only Cu and Zn of heavy metals were detected 0.001~0.009 and 0.007~0.091mg/L, but Pb, Cd, Cr and Ni were not detected When supplied $4,250m^3$ of an irrigation water into 1.0㏊ of paddy field, natural supplies of nutrient materials were 29.67㎏ of T-N, 1.80㎏ of $NH_4-N$, 24.57kg of NO3-N and 0.51kg of T-P. Also $Ca^{++},\;Mg^{++},\;Na^+,\;K^+,\;Cl^-\;and\;SO_4\;^{2-}$ were supplied 9.42, 7.09, 13.34, 9.08, 40.27 and 41.38kg respectively. Only Cu and Zn of heavy metals were supplied 0.017kg of Cu and 0.133kg of Zn, Pb, Cd, Cr and Ni were not supplied

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.377-384
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• 2007

Present tooth bonding system can be categorized into total etching bonding system (TE) and self-etching boding system (SE) based on their way of smear layer treatment. The purposes of this study were to compare the effectiveness between these two systems and to evaluate the effect of number of themocycling on microleakage of class V composite resin restorations. Total forty class V cavities were prepared on the single-rooted bovine teeth and were randomly divided into four experimental groups: two kinds of bonding system and another two kinds of thermocycling groups. Half of the cavities were filed with Z250 following the use of TE system, Single Bond and another twenty cavities were filled with Metafil and AQ Bond, SE system. All composite restoratives were cured using light curing unit (XL2500, 3M ESPE, St. Paul, MN, USA) for 40 seconds with a light intensity of $600mW/cm^2$. Teeth were stored in distilled water for one day at room temperature and were finished and polished with Sof-Lex system. Half of teeth were thermocycled 500 times and the other half were thermocycled 5,000 times between $5^{\circ}C$ and $55^{\circ}C$ for 30 second at each temperature. Teeth were isolated with two layers of nail varnish except the restoration surface and 1 mm surrounding margins. Electrical conductivity (${\mu}A$) was recorded in distilled water by electrochemical method. Microleakage scores were compared and analyzed using two-way ANOVA at 95% level. From this study, following results were obtained: There was no interaction between variables of bonding system and number of thermocycling (p = 0.485). Microleakage was not affected by the number of thermocycling either (p = 0.814). However, Composite restoration of Metafil and AQ Bond, SE bond system showed less microleakage than composite restoration of Z250 and Single Bond, TE bond system (p = 0.005).

• Research in Plant Disease
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• v.21 no.2
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• pp.58-66
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• 2015

This study was conducted to evaluate control efficacy of a fermented food 'Cheonggukjang' against cucumber powdery mildew caused by Sphaerotheca fuliginea in greenhouse. Sterilized Daepung beans were inoculated with the rice straw as natural inoculum and then incubated for 72 hrs at $42^{\circ}C$ in the household cheonggkjang maker. After 72 hrs of cheonggukjang fermentation, white zymogens were grown on the surface of a sterile Daepung beans. The pH of the 72 hrs fermented soybean was not significantly changed and electrical conductivity was found to increase by about 2 times than before fermentation. The population density of soybean zymogen showed a peak of growth at 60 hrs after fermentation and the concentration of zymogen was $8.2{\times}10^7cfu/ml$. Soybean zymogen form of the colony was divided into three kinds of bacteria and a white and a large colony (WL) was predominant bacteria among those up to 60 hrs of fermentation. To control the cucumber powdery mildew, diluted solutions of cheonggukjang was applied from 6.0% to 30.0% on cucumber leaves and they showed injury symptoms on cucumber leaves in more than 15% of them. However, more than 6.0% diluted cheonggukjang solutions showed more than 77.8% control effect of cucumber powdery mildew at 15 days after treatment. The fermented bacteria of Chenggukjang were well established in the cucumber leaf area at 15 days after treatment. The antifungal activity of 10% diluted cheonggukjang solutions was excellent for four species of plant fungal pathogens, Colletotrichum gloeosporioides, Sclerotinia cepivorum, Rhizoctonia sloani and Phytophthora capsici in the dual culture test. Results indicated that foliar application of Cheonggukjang solution could be used for the control of powdery mildews occurring on organically cultivated cucumber.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.827-836
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• 1998

Background: Effective cardiopulmonary resuscitation (CPR) should provide acceptable hemodynamics for the vital organs during cardiac arrest and early restoration of spontaneous circulation that guarantees long-term, neurologically intact survival. CPR using heart-lung bypass has been suggested as an option for that use. This study was designed to determine the effectiveness of standard CPR techniques, closed-vs. open-chest CPR, which could be used in the future study verifying the role of heart-lung bypass CPR. Material and Method: By using adult mongrel dogs, closed-chest CPR (CCCPR, n=4) and open-chest CPR (OCCPR, n=5) were compared with respects to hemodynamics, restoration of spontaneous circulation(ROSC), and survival. Ventricular fibrillation-cardiac arrest (VF-CA) was induced by electrical shock in all animals. After 4 minutes of cardiac arrest, basic life support (BLS) was applied for 15 minutes and followed by advanced life support (ALS). ALS was maintained until achi ving ROSC but not longer than 30 minutes regardless of the recovery. Resuscitation procedures in either group were standardized by adopting the protocol of American Heart Association. Result: Prearrest baseline hemodynamic data was not different between two groups. During resuscitation, substantially higher systolic pressure was maintained in OCCPR group than in CCCPR group (45$\pm$15 vs. 33$\pm$11 mmHg during BLS, 83$\pm$36 vs. 44$\pm$15 mmHg during ALS; p=NS). Mean pulmonary arterial pressure went up to the level of mean systemic arterial pressures in CCCPR group and to half of that in OCCPR group, and had kept higher in CCCPR group throughout CPR (32$\pm$10 vs. 22$\pm$4 mmHg during BLS and 32$\pm$15 vs. 24$\pm$10 mmHg during ALS; p=NS). ROSC was obtained in 4 of 5 dogs receiving open-chest CPR and 2 of 4 closed-chest CPR. Prolonged survival was noted in all dogs in OCCPR group (6 to 1440 hours) but not in CCPR group (p<.05). Conclusion: These findings indicate that open-chest CPR can be more effective t maintain hemodynamics during cardiac arrest and to obtain restoration of spontaneous circulation and survival. Further experiment will be designed to compare heart-lung bypass CPR with open-chest CPR.