• Journal of Korean Society of Environmental Engineers
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• v.33 no.2
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• pp.120-131
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• 2011

A pilot-scale experiment of floodplain filtration with a filtration depth of 3.6m was performed employing flood/rest type raw-water supply system in an effort to find ways to improve river water quality by additional treatments of discharged effluent from sewage treatment plant. Soil samples were taken from 3 sites including Gumi, Daegu and Gimhae along the Nakdong river. Reductions of infiltration rates following increases in operating time was investigated in each soil sample, along with the analysis of removal efficiencies of various pollutants according to different depths and infiltration rates. The results show incremental development of clogging on the soil surface with increases in operation time, and illustrate exponential decrease in the infiltration rate. The time required for the removal of the clog from the soil surface was longer than 2 weeks for all soil samples analyzed. The stable infiltration rates for soils were 5 m/day for Gumi and for Daegu and Gimhae was 1 m/day. In unsaturated soils dissolved oxygen levels increased following the increase of filtration depth, suggesting that alternating application of flood and rest for raw-water supply effectively keeps the soil environment aerobic. For all soils, the nature of pollutant removal depending on the depth of filtration remained the same regardless of the infiltration rate. Most of the BOD and turbidity were removed within 1.2 m, about 30% of COD was removed within 3.6m and was expected to be removed further with increases in filtration depth. Nitrification occurred near the surface of all soils; however there was no significant removal of nitrogen in the filtration depths tested in this study. Although removal rate of phosphorus was low for Gumi's soil, it was high enough for other soils, suggesting that the method developed in this study could significantly improve river water quality.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.369-380
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• 2017

Objectives: The purpose of this study is to investigate the effect of preventive treatment experience on scaling fear level. Methods: A total of 259 adults who had visited the dental clinic were analyzed. The results were summarized as follows. Statistical analysis of the collected data was performed using the SPSS WIN 20.0 statistical program. The general characteristics, scaling experience, and the characteristics of the subjects were analyzed. Frequency of scaling according to general characteristics was analyzed by independent sample t-test, Scaling fears according to treatment experience were tested by t-test. Correlation analysis was performed for scaling fears according to the reliability of dental hygienist. Regression analysis was carried out to investigate factors affecting scaling fear. Results: Level of fear during scaling was higher in females (3.03) than in males (2.54) and that after scaling was scored higher in females (2.68) than in males (2.34) by general characteristics (p<0.001). The adults who were not healthy in oral health showed the highest levels of fear during (3.29) and after (3.00) scaling by oral health status (p<0.001). Adults who had brushing education experience showed lower fear level than those who did not after scaling (p<0.01) according to the experiences of preventive treatments. With respect to the correlation of trust level to the dental hygienists with the scaling fears, it showed higher in the trust level (-0.688) as lower level of scaling fear (-0.642) in the scaling (p<0.01). Confidence level of dental hygienist (-0.661), brushing education experience (-0.121), and oral health status (-0.121) were influenced upon the regression analysis. Conclusions: Oral health education and dental hygiene education are increasing. It is thought that active efforts are needed to promote and maintain oral health.

• Journal of the Korean Wood Science and Technology
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• v.41 no.6
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• pp.535-543
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• 2013

The objective of this study was to analyse the residual stress in Larix kaempferi board during and after kiln-drying. The boards were primarily intended for using as laminar of cross laminated timber (CLT). In this study, the equivalence of moisture content by equalizing treatment was proved and reduction of residual stress by conditioning treatment was quantified. Prong test and slice test were carried out to analyse the residual stress in wood during drying. Transverse casehardening was measured immediately after making prong sample. Residual stress of four parts in wood from surface to center was analyzed quantitatively based on elastic deformation after just cutting slices from board. Tensile stress and compressive stress on the surface of board during drying did not exceed 2.2 MPa when boards were dried by kiln-drying schedule of T10-C4 and T12-D5. Because the tensile strength and compressive strength of transverse direction of Larix kaempferi lumber are 2.65 MPa and 4.60 MPa, application of more severe drying schedule can be recommended. Cup and twist were reduced by about 40% by equalizing and conditioning treatments after drying.

• Applied Biological Chemistry
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• v.32 no.2
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• pp.91-97
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• 1989

For the effective use of soymilk residue (SR), by-product of soymilk production, barley Doenjang was manufactured. As the results, the contents of reducing sugar increase3 for 50 days in all samples and decreased thereafter. The contents of amino nitrogen increased prominently for 50 days, but increasing ratio was slightly slowdowned thereafter. The higher mixing ratio of SR, the less were the contents of reducing sugar and amino nitrogen. The contents of total acid also increased prominently for 30 days, but were slowdowned thereafter and the differences among all treatments were negligible. As the mixing ratio of SR was increased, the lightness and the yellowness increased and the redness decreased in 80days aged samples. In sensory evaluation of 90 days aged samples, the control was the best in soy sprout Doenjang soup. As the mixing ratio of SR increased, the taste was dropped slightly but no significant differences were obtained among sample A(barley koji 100, soybean 75, SR 25), B(barleykoji 100, soybean 50, SR 50) and C(barley koji 100, soybean 25, SR 75). In the original taste of Doenjang, the control was the best and as the mixing ratio of SR was increased, the point was dropped but these were no significant differences among control, A and B, and among A, B and C, and among B, C and D(barley koji 100, soybean 0, SR 100).

• Applied Biological Chemistry
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• v.32 no.2
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• pp.98-103
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• 1989

For the effective use of soymilk residue (SR), by-product of soymilk production, rice Doenjang was manufactured. As the results, the contents of reducing sugar were increased till $40{\sim}50days$ in all samples and decreased thereafter during aging of the mash. The contents of amino nitrogen were prominently increased till 50days, but increasing ratio was slightly slowdowned thereafter. The higher mixing ratio of SR, the less were the contents of reducing sugar and amino nitrogen. The contents of total acid were also prominently increased till 30days, but were slowdowned thereafter and the differences among all treatments were small. As the mixing ratio of SR was increased, the lightness and the yellowness were increased and the redness was decreased in 80days aged samples. In sensory evaluation of 90days aged samples, control was the best in soy sprout Doenjang soup. As the mixing ratio of SR was increased, the taste was dropped slightly but no significant differences were obtained between control and sample A (rice koji 100, soybean 75, SR 25), and among A,B(rice koji 100, soybean 50, SR 50). C(rice koji 100, soybean 25, SR 75) and D(rice koji 100, soybean 0, SR100). In the original taste of Doenjang, the control was the best and as the mixing ratio of SR was increased, the point was dropped but there were no significant differences between control and A, and among A, B and C, and among B, C and D.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.39-46
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• 2020

This study evaluated the nitrogen oxide (NO_x) removal efficiency by air purification concrete blocks with titanium dioxide (TiO₂). The concrete in the mixtures had a 30% water:cement ratio, to which TiO₂ was added at 0%, 5%, and 10% of cement weight. The compressive strength reduction rate and removal efficiency of NO_x were investigated. The result of the compressive strength test in the study indicated that addition rate of TiO₂ did not lead to signifcant effect. In terms of the average removal efficiency of NO_x, mix No. 1 using a TiO₂ mixing ratio of 0% had a removal efficiency of 0.57% on average; thus, the removal effect w as not significant. For the other samples prepared by mixing, the average removal efficiencies for mix No. 2 (5% TiO₂) were 58.86% and 62.05% for normal and washing surface treatments, respectively, and those of sample No. 3 (10% TiO₂) were 59.94% and 67.61%. mixs No. 4 (5%) and No. 5 (10%), in which TiO₂ diluted with distilled water was sprayed onto the block surface, had an average NO_x removal efficiency of 61.72% and 68.48%, respectively. In terms of NOx removal efficiency, Mixs No. 3 and No. 5 with 10% TiO₂ were better than Mixs No. 2 and No. 4 with 5% TiO₂. In addition, analyzing the NO_x removal efficiency results from the fixing method, it was capable to apply mixing (washing) and the diluted spray methods. Therefore, it was found that the diluted spray method applied in this study can be employed in any manufacture of air purification concrete blocks.

• Journal of Conservation Science
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• v.33 no.5
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• pp.381-390
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• 2017

Desalination is the main focus of the stabilization of iron artifacts. However, drawbacks such as re-corrosion are noted due to the uncertainty in the elimination of the corrosive factors and artifacts. Several studies have been carried out on the effects of corrosion inhibitors to overcome these shortcomings. In this study, the effects of type 3 water treatment on corrosion inhibitors were investigated. Surfaces of samples that contained film corrosion inhibitors on their surfaces were analyzed. The results revealed that the surface rust was removed from the sample of type 1 No. 2 that was mainly composed of phosphate. The average weight reduction rates of re-corrosion samples were 0.58, 0.03, and 0.07% for type 1 No. 2, type 2 No. 2, and type 3 No. 2 respectively. The changes in the $Cl^-$ ion, a corrosive agent were found to be 28.60, -4.08, and -1.94 ppm for type 1 No. 2, type 2 No. 2, and type 3 No. 2 respectively. The water-treated films were analyzed by X-ray photoelectron spectroscopy (XPS). It was found that type 2 No. 2 had less Fe the basis metal, than that in type 3 No. 2 indicating much better film. Moreover, Si content was higher in type 2 No. 2, based on the silicate content, than in type 3 No. 2. They are speculated to be the reason or the formation of a better film. Type 1 No. 2, which is mainly composed of phosphate, would be inappropriate as a metal artifact conservation treatment. It was determined that type 2 No. 2 and type 3 No. 2 water treatments, which are mainly composed of silicate, provided excellent corrosion inhibiting effects. Corrosion inhibitors could be used as emergency treatment agents during the excavation of iron artifacts.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.183-188
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• 2017

This study investigated the comparative growth characteristics, yield, chemical compositions, and nutritive yield of Italian ryegrass cultivars harvested in a paddy field. The experimental design was a randomized block design with three replicates. The treatments consisted of seven Italian ryegrass cultivars (Kogreen, Kowinmaster, Hwasan 101, Kowinnearly, Kospeed, Sahalie select, and Strike). The planting date was October 21, 2009 and the sample harvest was occurred on May 21, 2010. Dry matter yield was higher in Kowinnerary and Kogreen than in the other varieties (p<0.05). Crude protein and ether extract contents were highest in Hwasan 101 and lowest in Kospeed. The content of total digestible nutrients did not differ among the Italian ryegrass varieties. The amino acid contents were in the order Hwasan 101 > Strike > Kowinnearly > Kogreen > Sahalie select > Kospeed > Kowinnearly (p<0.05). Fructose content was highest in Kospeed, while glucose and sucrose contents were highest in Hwasan 101. The results of this study indicate that Kowinnearly, in terms of dry matter yield, and Hwasan 101, in terms of feed value (chemical composition and free sugar content), may be recommended for forage production in a paddy field.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.329-333
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• 2011

Quality characteristics of tofu as affected by addition time (before or after coagulant) and the amount (0, 3, 6, and 9%) of astringent persimmon fruit (Diospyros kaki T. cv. Cheongdobansi) powder added were investigated. Yield and sensory acceptability were higher in tofu prepared by adding persimmon before than after adding the coagulant. The yield of tofu with added persimmon was higher than that of the control. The L value of the tofu decreased as the amount of added persimmon increased. Hardness, chewiness, and crispness of tofu made with 6% persimmon were higher than those of the others. DPPH radical scavenging activity tended to increase as persimmon concentration increased but no significant difference was observed between the 3% and 6% added persimmon treatments. A sensory evaluation showed no significant differences in aroma, beany, astringency, and texture. However, the 9% sample had the significantly lowest score for overall acceptability. Thus, astringent persimmon powder (3-6%, before coagulant addition) can be utilized as an additive during tofu processing.

• Journal of Animal Science and Technology
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• v.50 no.2
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• pp.237-246
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• 2008

Four different pork loaves were made with two levels, HP/FP-3% and HP/FP-6%, containing 3.0 and 6.0% HP(hot air dried sweet persimmon powder)/FP(freezer dried sweet persimmon powder), respectively. HP and FP(3% and 6%) were added into ground pork loin separately. A control without persimmon powder were used for comparison. Patties were cooked to 74℃ in electric oven, after cooling, the aerobic packaged meat loaves were stored at 5℃. The moisture and crude ash were higher in the FP-6%, and the crude protein and crude fat were no different among the samples. The pH in control sample was significantly higher(p<0.05) than those of treatment group, however no significant difference was found among the 4 treatments. The TBARS(thiobarbituric reactive substance) values of all samples showed a tendency of increasing value along the storage days. The TBARS and a* value increased(p<0.05) as the addition ratio of HP/FP increased, respectively. With regard to microorganisms, the number of total aerobic bacteria were lower than 3.11 log10 CFU/g. In sensory evaluation, meat loaves containing persimmon powder resulted in a high overall acceptability, although they were not significantly different in overall acceptability.