• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.99-110
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• 2018

In this study, oil of Platycodon grandiflorum seeds was prepared using supercritical carbon dioxide extraction (SCE) and its physicochemical indices as a new edible oil were investigated. Compared to Soxhlet solvent extraction, SCE under the condition of 6,000 psi at $40^{\circ}C$ produced more oil, especially from the roasted seeds to 32.7%. TLC analysis showed triacylglycerols accounted for most of the oil obtained from roasted Platycodon grandiflorum seeds by SCE similarly to commercial soybean oil or perilla seeds oil. The oil had highly unsaturated lipid with considerable amount of linoleic acid(73.27%) much more than two commercial oils followed by oleic acid(13.16%). Physicochemical properties of the oil were as follows; specific gravity, 0.92; dynamic viscosity, 45.37 cP; refractive index, 1.48; color, L=47.30, a=-3.69, b=25.72; iodine value, 141.57 g $I_2/100g$ oil; saponification value, 191.21 mg of KOH/g of oil; acid value, 2.60 mg of KOH/g of oil. Among those, refractive index, viscosity and iodine value, which were related to unsaturation degree of lipid, were ranged between those of two commercial oils. The oxidation stability of oil(2.03 hr) was also ranged between less stable perilla seeds oil(1.79 hr) and more stable soybean oil(2.94 hr) based on the induction time measured by Rancimat assay. In addition to extraction yield increase, seeds roasting provided further benefits such as reductions of cholesterol ester content and acid value without change in fatty acid composition. In conclusion, oil was extracted from the roasted Platycodon grandiflorum seeds at high yield by supercritical carbon dioxide and it seemed to have proper characteristics as a edible oil.

• Journal of Conservation Science
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• v.21
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• pp.5-20
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• 2007

The stone artifacts in Bronze age from the Hyocheon sites in the Gwangju, Korea were studied on the basis of material characteristics and provenance presumptions. The use and rock names of the artifacts are a stone shovel by andesite, the stone grinding pestle by pyrophyllite, the stone sickle by schist and four stone semifinished artifacts by slates. Andesitic stone shovel could be observed easily around the Hyocheon relic site. But, rocks of the stone grinding pestle, the stone sickle, the stone arrowhead and the stone semifinished artifacts could be confirmed typical occurrences of the all kinds of rocks around the Hwasun coal mine area above 10km from the site. These are made the coupled samples with each stone artifact to the same kinds of raw material rocks based on analysis of the lithology and geochemistry. As a result a geochemical evolution trends of both a stone artifact and the rock showed very similar patterns based on normalization using the behavior, enrichment, compatibility and incompatibility of the elements. Therefore, the source rock of the stone shovel was convey from Mudeung mountain possible interpreted that the domestic-type artifacts are distributed in the vicinity of the Hyocheon site. On the other hand, the stone grinding pestle, the stone sickle, the stone arrowhead and the stone semifinished artifacts were convey from the Hwasun coal mine area possible foreign-type stone artifacts interpreted that the source rocks. Consequently, in the foreign-type stone artifacts are should archaeologic research which it can examine various possibilities clearly that the possibility to coming the introduction with the mankind migration, diffusion to dealings of tribe, the captured enemy equipment through the war and the trade with the behavior of the materials.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.687-693
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• 2006

The Stone Powder Sludge(below SPS) is the by-product from the process that translates stone power of 8mm under as crushed fine aggregate. It is the sludge as like cake that has average particle size of $7{\mu}m$, absorbing water content of 20 to 60%, and $SiO_2$ content of 60% over. Because of high water content of SPS, it is not only difficult to handle, transport, and recycle, but also makes worse the economical efficiency due to high energy consuming to drying. This study is aim to recycle SPS as it is without drying. Target product is the lightweight foamed concrete that is made from the slurry mixed with pulverized mineral compounds and foams through hydro-thermal reaction of CaO and $SiO_2$. Although in the commercial lightweight foamed concrete CaO source is the cement and $SiO_2$ source is high purity silica powder with $SiO_2$ of 90%, we tried to use the SPS as $SiO_2$ source. From the experiments with factors such as foam addition rate and replacement proportion of SPS, we find that the lightweight foamed concrete with SPS shows the same trends as the density and strength of lightweight foamed concrete increases according to decrease of foam addition rate. But in the same condition, the lightweight foamed concrete with SPS is superior strength and density to that with high purity silica. This trends is distinguished according to increase of replacement proportion of SPS, also the analysis of XRF shows that the hydro thermal reaction translates SPS to tobermorite. Although SPS has low $SiO_2$ contents, the lightweight foamed concrete with SPS has superior strength and density, because it reacts well with CaO due to extremely fine particles. We conclude that it is possible to replace the high purity silica as SPS in the lightweight foamed concrete experimentally.

• Journal of Korean Society of Forest Science
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• v.67 no.1
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• pp.42-49
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• 1984

The elderberry was known to the ancients for its medicinal properties, and in Europe the inner back was formerly administered as a cathartic. The flowers contain a voletile oil, and serve for the distilation of elder-lower water, used in confectionery, perfumes and lotions. The leaves are employed to impart a green colour to fat and oil, and the leaves and bark emit a sickly odour, believed to be repugnant to insect. With its unique flavor and natural food colour, commercial processing companies used the fruit mainly in the making for jam, jelly, pies, juice, and wines. Its vitamin-C content is reported by Andross (1941) as 25-30mg/100g. Harvesting and processing have been mechanized to some extent. However, the cotains with nutritional value has not been reported yet. In the present study the various contains with nutritional value in the fresh elderberry juice is reported by the quantitative analysis. In this study results obtained can be summarized as follows. 1) The fresh elderberry juice contained following mineral elements; calcium 0.012%, magnesium 0.023%, potassium 0.10%, sodium 0.0019%, iron 0.0009%, cobalt 0.0002%, zinc 0.0004%, copper 0.0001%, phosphorus 0.036%, manganese 0.0006%, iodide $1{\mu}g/g$. 2) Five kinds of vitamines were also found ; vitamin-$B_1$ $0.1{\mu}g/g$, vitamin-$B_2$ $0.5{\mu}g/g$, vitamin-C 0.3mg/g, niacin $14{\mu}g/g$, choline chloride 0.3mg/g. 3) Fresh elderberry juice also contains crude protein 1.10%, fat 0.26%, carbohydrate 6.9%, pectin 0.76%, tannin 0.89%, ash 0.80%, water 90.9% and 34.3 cal/100g. 4) The absorption spectrum of the purplishblack color of fresh elderberry juice has a peak between 523-530mm.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.143-150
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• 2009

High salt concentration is one of the most important limit factor on plant growth at a disused saltpan for golf course construction site. The control of salt in soil is definitely required and the monitoring of salt concentration in soil and ground water also required to amend soil physiochemical properties. This research was carried out to monitor the pH and salt concentration changes by the height of ground water. By the physiochemical analysis test, the soil contains a high salt concentration and classified as a slight alkaline clay soil. The height of ground water table changed to 1.3m, 3.3m and 2.8m at dry season(mid-late June, 2005), monsoon season(early-mid July) and after monsoon(late July), respectively. Compare to the average ground level of 2.9m, the ground water was over flooded about OAm at monsoon season. The electrical conductivity(ECe) was measured above $4.0dS{\cdot}m^{-1}$ over all areas and however, some areas showed over $20dS{\cdot}m^{-1}$. During a monsoon season, ECe was lowered to $1.2{\sim}15.0dS{\cdot}m^{-1}$, compared with those of the dry season. Therefore, the interception of the capillary connection between planting layer and ground water which contains high salt concentration should be adapted when golf courses are constructed on disused saltpan. The phytotoxicity caused by salt damage may be controled by the interception of capillary fringe of salt flow to the topsoil profile at the upper layer of the ground water table.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.227-231
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• 2010

Slurry composting biofiltration(SCB) is considered as a treatment to produce a better fertilizer resource than raw pig slurry as it reduces odor and improves nutrients imbalance. For the agricultural use of SCB slurry as a nutrient source with minimum environmental impact, it is important to investigate the effect of different rate of SCB slurry application on nutrient (particularly for nitrogen) uptake and growth of crops. This study was conducted to investigate the influence of fertigation using pig slurry(PS) on growth and yield of red pepper and to evaluate the appropriate PS concentration in fertigation for soils with different nitrate concentration. To evaluate the effects of fertigation applied PS as a substitute of chemical fertilizer(CF), a single application of three different concentrations of PS: $N_{0.5}$ (43 mg/L), $N_{1.0}$ (86 mg/L) and $N_{1.5}$ (131 mg/L) were compared with CF $N_{1.0}$ (89 mg/L) as a control nitrogen fertilizer. Statistical analysis showed that the growths of red pepper were not affected by treatments. In addition, the yields were no significant difference among treatments, though the highest yield was obtained in PS $N_{1.0}$ by 20,580 kg/ha. In soil chemical properties, nitrate nitrogen on soil of between PS N1.0 and CF $N_{1.0}$ treatment showed similar patterns although they were higher than the preplant nitrogen content. Also, there was no significant difference in yield of red pepper between PS and CF treatment applied as fertigation on soils where nitrate nitrogen contents of each soil contains 10, 100 and 200 mg/kg respectively. Consequently, the application of PS, such as SCB, as a substitute of CF is available for growth and yield of red pepper, there could be accordingly estimated the optimal fertigation concentration of PS for red pepper cultivation.

• Journal of Educational Research in Mathematics
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• v.21 no.4
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• pp.327-344
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• 2011

This study is the first step for us toward improving high school students' capability of statistical inferences, such as obtaining and interpreting the confidence interval on the population mean that is currently learned in high school. We suggest 5 underlying concepts of 'discretion of contingency and inevitability', 'discretion of induction and deduction', 'likelihood principle', 'variability of a statistic' and 'statistical model', those are necessary to appreciate statistical inferences as a reliable arguing tools in spite of its occasional erroneous conclusions. We assume those 5 concepts above are to be gradually developing in their school periods and Korean mathematics textbooks of grades 1-12 were analyzed. Followings were found. For the right choice of solving methodology of the given problem, no elementary textbook but a few high school textbooks describe its difference between the contingent circumstance and the inevitable one. Formal definitions of population and sample are not introduced until high school grades, so that the developments of critical thoughts on the reliability of inductive reasoning could not be observed. On the contrary of it, strong emphasis lies on the calculation stuff of the sample data without any inference on the population prospective based upon the sample. Instead of the representative properties of a random sample, more emphasis lies on how to get a random sample. As a result of it, the fact that 'the random variability of the value of a statistic which is calculated from the sample ought to be inherited from the randomness of the sample' could neither be noticed nor be explained as well. No comparative descriptions on the statistical inferences against the mathematical(deductive) reasoning were found. Few explanations on the likelihood principle and its probabilistic applications in accordance with students' cognitive developmental growth were found. It was hard to find the explanation of a random variability of statistics and on the existence of its sampling distribution. It is worthwhile to explain it because, nevertheless obtaining the sampling distribution of a particular statistic, like a sample mean, is a very difficult job, mere noticing its existence may cause a drastic change of understanding in a statistical inference.

• Applied Microscopy
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• v.38 no.4
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• pp.279-284
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• 2008

The phase change materials have been extensively used as an optical rewritable data storage media utilizing their phase change properties. Recently, the phase change materials have been spotlighted for the application of non-volatile memory device, such as the phase change random access memory. In this work, we have investigated the crystallization behavior and microstructure analysis of In-Sb-Te (IST) thin films deposited by RF magnetron sputtering. Transmission electron microscopy measurement was carried out after the annealing at $300^{\circ}C$, $350^{\circ}C$, $400^{\circ}C$ and $450^{\circ}C$ for 5 min. It was observed that InSb phases change into $In_3SbTe_2$ phases and InTe phases as the temperature increases. It was found that the thickness of thin films was decreased and the grain size was increased by the bright field transmission electron microscopy (BF TEM) images and the selected area electron diffraction (SAED) patterns. In a high resolution transmission electron microscopy (HRTEM) study, it shows that $350^{\circ}C$-annealed InSb phases have {111} facet because the surface energy of a {111} close-packed plane is the lowest in FCC crystals. When the film was heated up to $400^{\circ}C$, $In_3SbTe_2$ grains have coherent micro-twins with {111} mirror plane, and they are healed annealing at $450^{\circ}C$. From the HRTEM, InTe phase separation was occurred in this stage. It can be found that $In_3SbTe_2$ forms in the crystallization process as composition of the film near stoichiometric composition, while InTe phase separation may take place as the composition deviates from $In_3SbTe_2$.

• Journal of Life Science
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• v.28 no.5
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• pp.517-523
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• 2018

Elevated levels of cortisol caused by chronic stress may lead to neuron damage in the hippocampus by activating the glucocorticoid receptors (GRs). In cortisol-deficient animals, corticosterone is known to function as a stress hormone. In humans however, corticosterone is considered a precursor of aldosterone and a glucocorticoid with similar properties to cortisol. Recently, many studies have been conducted on the role of cortisol and other synthetic glucocorticoids like dexamethasone in humans, but the exact function of corticosterone is unknown. This study examined the viability of human neuroblastoma SH-SY5Y cells treated with various concentrations of corticosterone for 24 and 48 hr via MTT assay. The MTT-assay results showed that corticosterone had an antiproliferation effect on SH-SY5Y cells at higher concentrations (500 and $1,000{\mu}M$), while in lower concentrations ($100{\mu}M$), it showed no antiproliferation effect. Cytotoxicity analysis of extracts from three medicinal crops (Liriope muscari, Schisandra chinensis, and Wolfiporia extensa) revealed that they all possessed deleterious effects on SH-SY5Y cells depending on dosage. However, it was observed that, at a concentration of $500{\mu}g/ml$, Liriope muscari attenuated the corticosterone-induced antiproliferation on SY-SH5Y cells and restored cell growth after 48 hours of treatment. The study examined the synergistic effect of six mixtures each containing $500{\mu}g/ml$ of Liriope and various concentrations of Schisandra (50 or $100{\mu}g/ml$) and Wolfiporia (10, 30, and $50{\mu}g/ml$). The results showed minor growth-restoration activity but less than that of Liriope muscari only, suggesting that Schisandra and Wolfiporia had no additive or synergistic effects.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.259-264
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• 2015

For this experiment, specimen was manufactured by injecting polymer and monomer into silicon mold with volume ratio of 2.5:1 based on ISO 20795-2 so that average thickness, width and length of specimen would be maintained as 3.3 mm, 10.0 mm and 65.0 mm, respectively depending on spray on technique. Specimen was divided into 3 groups ($25^{\circ}C$, $40^{\circ}C$, $70^{\circ}C$) depending on polymerization temperature and 10 specimen was manufactured for each group and it was polymerized in water tank of ${\pm}1^{\circ}C$ under the setting condition of polymerization time of 15 minutes and pressure of 3 bar. After keeping specimen in distilled water of $37^{\circ}C$ for over 48 hours before experiment, flexural strength (FS) and elasticity modulus (EM) of specimen being tested by using Intron (3344; Instron; Instron). SPSS ver. 16.0 was used for analysis and post-hoc test of Scheffe was performed after using one-way ANOVA. When comparing mean value of FS of resin for orthodontics, it was represented in the range of 71.500 MPa for $25^{\circ}C$ group, 74.920 MPa for $40^{\circ}C$ group and 76.880 MPa for $70^{\circ}C$ group and difference was shown in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group but such difference was not significant statistically (p=0.052). Result of EM mean value of resin for orthodontics was more polymerization temperature was high, the more was significant difference represented in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group (p<0.039).