• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.244-255
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• 2018

Natural extract in liquid phase was adjusted to 0, 0.25, 0.5, 1, 2, and 4% concentration to check microbial changes and to measure 4, 8, $12^{\circ}C$ for refrigeration temperature. In the case of grapefruit extract, the microbial safety was maintained at all the concentrations at $4^{\circ}C$ storage, but the antimicrobial activity was maintained at $12^{\circ}C$ storage and at $8^{\circ}C$ and 21 days storage. In the case of grape seed extract, only the 4% of the culture at $8^{\circ}C$ satisfied the requirement of safety of food distribution for the last 21 days, and the safety criterion was satisfied only at 4% concentration at $12^{\circ}C$ for 18 days. Complex Scutellaria baicalensis extract showed the total number of microbial cells treated by concentration. It was confirmed that microbial flow safety was maintained at low temperature ($4^{\circ}C$). However, at $8^{\circ}C$ and $12^{\circ}C$, Exceeded the distribution limit. When polylysine was applied to brown rice cake, it showed activity in all groups except $4^{\circ}C$, but these properties were not observed at $8^{\circ}C$ and $12^{\circ}C$. At a concentration of 0.5% or more of chitosan, the growth of the microorganism is suppressed by the 21st day very stably, and a similar tendency is observed at 8 and $12^{\circ}C$, so that it may be an antimicrobial material that inhibits microorganisms. At the first day, the distribution standards for general bacterial counts were exceeded.Ethyl-pyruvate showed that microorganism safety was maintained at $4^{\circ}C$ and 1% concentration, and food safety was stable even at 2 or 4%. Glycine showed very good and stable distribution stability at $4^{\circ}C$. However, at $8^{\circ}C$ and $12^{\circ}C$, the shelf life of 14 days could not be maintained as with the addition of other antimicrobial active substances.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.73-81
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• 2018

Purpose : The aims of this study were to compare and assess the effectiveness of Volumetric Modulated Arc Therapy(VMAT) using jaw tracking(JT) and fixed jaw(FJ) in radiation therapy of multiple brain metastasis. Methode and material : Among the patients with Multiple Brain Metastasis treated with jaw tracking, 10 patients with more than 6 tumors and with the size of radiation field $14{\times}14cm^2$ or more were included. Each Treatment plans with jaw tracking(JT) and fixed jaw(FJ) was established with Eclipse (Ver. 13.6 Varian, USA). Gamma Index (3 mm, 3 % confidence interval - 95 %) and maximum dose difference were measured with an electronic portal imaging device(EPID). The $D_{max}$ and $D_{mean}$ of Organ At Risk(OAR) were assessed and compared, and the Conformity Index(CI) and Homogeneity Index(HI) were evaluated. Result : Evaluating jaw tracking(JT) and fixed jaw(FJ) outcomes, in all cases, Gamma Index met the permissible standard of 3 mm, 3 % confidence intervals of 95 %. The maximum dose difference value from the areas with leaf end transmission was measured at a maximum of 98.4 % and an average of 43.6 % in clockwise(CW), and 67.9 % and 41.0 % for each in Counter-Clockwise(CCW). With jaw tracking, the maximum value of $D_{max}$ for each normal organ in OAR decreased in 15.36 %~74.59 % with the average value decreasing in 2.84 %~39.80 %. The maximum value of $D_{mean}$ in OAR decreased in 27.90 %~65.23 %, with the average value decreasing in 7.70 %~41.71 %. No change has been found in Conformity Index and Homogeneity Index values. Conclusion : When Jaw tracking is used in treating patients with multiple brain metastasis with VMAT, the unnecessary exposure due to leakage and transmission of radiation in unspecified areas was reduced, without affecting the dose distribution of the planning target volume(PTV), and the availability of radiation therapy with lower doses in normal organs is expected.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.339-344
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• 2006

A lot of organic wastes have been produced from diverse industries, they must be tested by the regulation of fertilizer control act if reuse the organic wastes for agricultural utilization. The regulation has had only two criteria; the content of organic matter and 8 heavy metals. This study was conducted to evaluation trace element (boron, cobalt, molybdenum, and selenium) and distribution of organic compounds with different classification for complement the regulation in 16 organic waste materials(62 samples) collected from different regions and industries. Contents of boron(leather industry sludge, $154.2mg\;kg^{-1}$; food company sludge, $57.1mg\;kg^{-1}$), cobalt(industrial area sewage sludge, $95.2mg\;kg^{-1}$; metropolitan sewage sludge, $22.9mg\;kg^{-1}$), molybdenum(metropolitan sewage sludge, $40.1mg\;kg^{-1}$; food company sludge, $16.8mg\;kg^{-1}$), selenium (fiber industry sludge, $28.1mg\;kg^{-1}$; leather industry sludge, $16.9mg\;kg^{-1}$; food company sludge, $15.9mg\;kg^{-1}$) were highest compare to the other organic wastes. Total PAHs contents were the highest in paper-mill manufacture($3,462ug\;kg^{-1}$), and among the 16 PAHs, naphthalene, phenanthrene, pyrene, fluoroanthene, Anthracene and acenaphthene were detected more clearly than others in all kinds of organic resources.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.163-179
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• 2003

Multifunctionality of agriculture which is not traded on the market now has been an important international issue in that it environmental and public benefits. We carried out to modify and to update the function of upland farming on flood prevention and fostering water resources. Economic values of environmental benefits were evaluated by replacement cost methods. Models to evaluate the function of preventing flood were selected as: (1)precipitation(flood-inducing) - runoff(A), (2) soil depth ${\times}$ soil air phase, (3) precipitation (flood-inducing) - runoff(B), (4) soil depth ${\times}$ effective porosity of soil. Models to estimate the function of fostering water resources were (1) saturated hydraulic conductivity (Ks) ${\times}$ duration of saturation(days) ${\times}$ (1-ratio of water flow directly into river), (2) precipitation ${\times}$ ratio of water fostered by rain resources ${\times}$ (area of upland/total land area), and (3) soil water retention quantity(under standing crop or tree) - SWRQ(in bare soil). Function of preventing flood was $883Mg\;ha^{-1}$ of water per year and 645 million Mg for the whole upland area. Function of fostering water resources was $94.1Mg\;ha^{-1}$ of water per year and 69 million Mg for the whole upland area. The value of flood-preventing function evaluated by replacement cost methods was estimated 1,428 billion won per year as compared to the cost for dam construction. The value of water resource fostering were estimated 8.6 billion won in the price of living water.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.267-271
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• 2010

A new black seed coat soybean cultivar, 'Daeheug', was developed at the National Institute of Crop Science (NICS) in 2007. The breeding goal for black seed coat soybean is to develop the cultivar with large seed size, high yield, lodging tolerance, and resistance to disease such as soybean mosaic virus (SMV), and bacterial pustule. 'Daeheug' was selected from the cross between 'Daehwang' which had yellow seed coat, large seed size, and late maturity, and 'Milyang 79' which was lodging tolerant, and SMV resistant with medium seed size, black seed coat, and yellow cotyledon. The preliminary, advanced and regional yield trials for evaluation and selection of this cultivar were carried out from 2003 to 2007. It has determinate growth habit, purple flower, brown pubescence, brown pod color, black seed coat, yellow cotyledon, spherical flattened seed shape, oval leaf shape and large seed size (34.3 g/100 seeds). In maturity, 'Daeheug' was 2 days later than the check cultivar 'Ilpumgeomjeongkong'. In the seed quality such as isoflavone contents ($635{\mu}g/g$), and anthocyanin contents ($11.2m{\ell}/g$ of seed coat), 'Daeheug' was better than the check cultivar. It has good adaptability for cooking with rice in ratio of water absorption and seed hardness. Specially, it has good processability for soybean tea with 2.13 absorbance at 530 nm, scavenge activity of DPPH radical was high, and contents of total phenolics was $1,263{\mu}g/m{\ell}$. The average yield of 'Daeheug' was 2.26 ton per hectare in the regional yield trials (RYT) carried out in six locations of Korea from 2005 to 2007.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.503-508
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• 2019

In short a binary value according to a change in the tube voltage by using one of VOLUME AXIAL MODE of scanning techniques of chest CT image quality evaluation in order to obtain high image and to present the appropriate tube voltage. CT instruments were GE Revolution (GE Healthcare, Wisconsin USA) model and Phantom used Pediatric Whole Body Phantom PBU-70. The test method was examined in Volume Axial mode using the pediatric protocol used in the Y university hospital of mass-produced material. The tube voltage was set to 70kvp, 80kvp, 100kvp, and mAs was set to smart mA-ODM. The mean SNR difference of the heart was $-4.53{\pm}0.26$ at 70 kvp, $-3.34{\pm}0.18$ at 80 kvp, $-1.87{\pm}0.15$ at 100 kvp, and SNR at 70 kvp was about -2.66 higher than 100 kvp and statistically significant (p<0.05) In the Lung SNR mean difference analysis, $-78.20{\pm}4.16$ at 70 kvp, $-79.10{\pm}4.39$ at 80 kvp, $-77.43{\pm}4.72$ at 100 kvp, and SNR at 70 kvp at about -0.77 higher than 100 kvp were statistically significant. (p<0.05). Lung CNR mean difference was $73.67{\pm}3.95$ at 70 kvp, $75.76{\pm}4.25$ at 80 kvp, $75.57{\pm}4.62$ at 100 kvp and 20.9 CNR at 80 kvp higher than 70 kvp and statistically significant (p<0.05) At 100 kvp of tube voltage, the SNR was close to 1 while maintaining the quality of the heart image when 70 kvp and 80 kvp were compared. However, there is no difference in SNR between 70 kvp and 80 kvp, and 70 kvp can be used to reduce the radiation dose. On the other and, CNR showed an approximate value of 1 at 70 kvp. There is no difference between 80 kvp and 100 kvp. Therefore, 80 kvp can reduce the radiation dose by pediatric chest CT. In addition, it is possible to perform a scan with a short scan time of 0.3 seconds in the volume axial mode test, which is useful for pediatric patients who need to move or relax.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.65-71
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• 2019

With regard to current Neck CT, Bismuth shielding boards are often being used to reduce exposure to superficial organs such as the thyroid. However, beam hardening often occurs near superficial organs with Bismuth shielding boards and variations in CT Number, Noise, and Uniformity values occur severely. This study looked into the usefulness of shielding boards made from aluminum and silicone that can be easily obtained and have good machinability by comparing them to the existing Bismuth shielding board. An Aluminum 7.3mm and a Silicone 21.5mm were made with shielding ratios similar to that of the Bismuth(0.06 mmPb). TLD (TLD-100) was placed on the thyroid area of the Phantom (RS-108T) and 5 doses were measured for each. To compare image quality, CT Number and Noise variations in axial images of the thyroid area in Neck CT images were compared. Also, variations in CT Number, Noise, and Uniformity were measured in the AAPM phantom images and compared. In the results, when thyroid doses for each shielding board were compared, the Bismuth shielding board showed a 14% reduction, the Silicone 21.5mm showed a 15% reduction, and the Aluminum 7.3mm showed a 13% reduction compared to the Non-Shield. Statistically, there were no significant differences in comparison with the Bismuth shielding board. In CT Number variations of thyroid area images, variations were largest for the Bismuth shielding board. With Uniformity evaluations of the AAPM phantom, the Bismuth shielding board was found unsuitable and the Aluminum 7.3mm and Silicone 21.5mm satisfied the acceptance criteria. Research results show that the Aluminum 7.3mm and Silicone 21.5mm have a similar shielding ratio to the high-priced Bismuth shielding board that is currently being used clinically and in comparison tests of CT Number attenuation coefficient variations, Noise, and Uniformity which are phantom image evaluation items, they proved to be better than Bismuth shielding boards. If various shielding boards are made using aluminum and silicone, sized appropriately for superficial organs, it would be useful in decreasing patient doses.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.127-133
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• 2019

Purpose: The purpose of present study was to investigate fracture strength and mode of failure of endodontically treated teeth restored with metal cast post-core system, prefabricated fiber post system, and newly introduced polyetherketoneketone (PEKK) post-core system. Materials and methods: A total of 21 mandibular premolar were randomly grouped into 3 groups of 7 each according to the post material. Group A was for metal cast post core; Group B for prefabricated glass fiber post and resin core; and Group C for milled PEKK post cores. All specimens were restored with metal crown. The fracture strength of each specimen was measured by applying a static load of 135-degree to the tooth at 2 mm/min crosshead speed using a universal testing machine. After the fracture strength measurement, the mode of failure was observed. The results were analyzed using Kruscal-Wallis test and post hoc Mann-Whitney U test at confidence interval ${\alpha}=.05$. Results: Fracture resistance of PEKK post core was lower than those of cast metal post and fiber reinforced post with composite resin core. In the aspect of fracture mode most of the root fracture occurred in the metal post core, whereas the post detachment occurred mainly in the fiber reinforced post. In the case of PEKK post core, teeth and post were fractured together. Conclusion: It is necessary to select appropriate materials of post for extensively damaged teeth restoration and clinical application of the PEKK post seems to require more research on improvement of strength.

• Korean Journal of Heritage: History & Science
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• v.54 no.3
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• pp.150-167
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• 2021

Since the advent of tertiary curriculum, middle school history education has been focused on political history, but many students perceive history as a simple memorization subject and complain about difficulties in abstract learning. The researcher saw this problem as caused by the history curriculum, and carried out this study for the purpose of proposing a revitalization of cultural property education in the middle school history curriculum. First, through the analysis of prior research, the usefulness of cultural property education, such as nurturing creative talent and realizing interactive history classes, was revealed, and the problems of the current political history-centered middle school history curriculum were pointed out. Afterwards, as a result of conducting an opinion survey on middle school 3rd grade students and social studies teachers, it was found that first, both middle school students and their teachers thought that the current political history-centered history had much room for improvement. Second, all groups agreed on the necessity of cultural property education in history education. However, in reality, it was found that it was not easy to sufficiently educate students about cultural property in a political history-centered curriculum. Third, teachers thought that it was necessary to improve the current history curriculum in order to enhance cultural property education. Based on these findings, the researcher suggested an improvement plan for the 2015 revised history curriculum. First, in the 'nature of the subject' section, cultural properties and historical materials should be included, and in the 'objective' section, politics, economy, society, and culture should be included. Contents related to cultural properties should be added to the sub-themes in the 'content system and achievement standards', and cultural properties-related contents should be further reinforced in the achievement standards, 'teaching, learning and evaluation'. It was suggested that this section should include cultural property learning and historical material learning, and guidance on teaching and learning methods of cultural property education should be added. If these aspects are reflected in the 2022 revised curriculum that is currently being developed, cultural property education will be improved, and more lively history education will be provided to students.

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.51-59
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• 2021

In this study we analyzed the elution rates of 11 metals from 82 metallic kitchen utensils purchased in the market. The elution frequency of the 11 types of metals was iron > aluminum > chromium, nickel > zinc > copper > lead > arsenic > antimony > stannum > cadmium. For metallic kitchen utensils, the elution rate of heavy metals was 7.3-93.9%, and the average elution concentration was 0.001-13.473 mg/L. The average elution concentration of heavy metals was ranged between none-detected (N. D.) to 30.473 mg/L for non-coated kitchen utensils and 0.000-10.005 mg/L for coated kitchen utensils. The average elution concentration of metals from domestic kitchen utensils ranged from 0.001-25.145 mg/L, and from 0.000-33.518 mg/L for imported kitchen utensils. In particular, aluminum was found to be high in domestic kitchen utensils while iron was high in imported kitchen utensils. The average elution concentration of heavy metals was N.D.-2.670 mg/L for stainless steel, N.D.- 31.575 mg/L for aluminum, and N.D.-307.737 mg/L for iron. The amount of transition to food after cooking was investigated.