• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.297-302
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• 2017

Recently, building materials and air purification filters with eco-friendly charcoal are actively studying to reduce the concentration of radon gas in indoor air. In this study, radon reduction performance was assessed by designing and producing new panel-type activated carbon filter that can be handled more efficiently than conventional charcoal filters, which can reduce radon gas. For the fabrication of our panel-type activated carbon filter, first the pressed molding product after mixing activated carbon powder and polyurethane. Then, through diamond cutting, the activated carbon filter of 2 mm, 4 mm and 6 mm thickness were fabricated. To investigate the physical characteristics of the fabricated activated carbon filter, a surface area and flexural strength measurement was performed. In addition, to evaluate the reduction performance of radon gas in indoor, the radon concentration of before and after the filter passes from a constant amount of air flow using three acrylic chambers was measured, respectively. As a result, the surface area of the fabricated activated carbon was approximately $1,008m^2/g$ showing similar value to conventional products. Also, the flexural load was found to have three times higher value than the gypsum board with 435 N. Finally, the radon reduction efficiency from indoor gas improved as the thickness of the activated carbon increases, resulting in an excellent radon removal rate of more than 90 % in the 6 mm thick filter. From the experimental results, the panel-type activated carbon is considered to be available as an eco-friendly building material to reduce radon gas in an enclosed indoor environment.

• Culinary science and hospitality research
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• v.18 no.2
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• pp.182-196
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• 2012

This study investigates the optimal application of perilla leaves to fresh noodles in terms of a variety of beneficial effects and functions such as the anti-microbial function of the leaves. First, we measured the water contents of the fresh noodles and found that the ones added with 7% lyophilized perilla leaf extract showed the maximum water contents whereas the control noodles without perilla leaf extract the minimum. Increasing amount of raw perilla leaf extract or lysophilzed perilla leaves in the fresh noodles elevated the L value and significantly reduced the A value. The mass and volume of the fresh noodles were gradually decreased with raw perilla leaves added. Addition of raw perilla leaf extract and lyophilized perilla leaves decreased the turbidity of the fresh noodles. Hardness of the fresh noodles was increased by the addition of lyophilized Perilla leaves. Next, we tested the effect of the addition of sesame leaves on microbial growth. No microbes were found in the fresh noodles in the absence or presence of sesame leaves at day 0. When the noodles were stored for 3 days, the greatest number of bacteria was detected in the noodles without perilla leaves while addition of perilla leaves lowered the amount of bacteria in the noodles. We then performed the sensory test. For the raw perilla leaf extract addition, the noodles with 9% of extract exhibited the highest in appearance, flavor, color (6.47), texture (6.60), and overall acceptability (7.67). Texture was the highest in the ones with 3% (6.87) and 5% (6.20) of extracts added. Overall acceptability (7.07) was the best when 3% perilla leaves were added. Overall, 9% addition of raw perilla leaf extract or 3% addition of lysophilized perilla leaves showed optimal tastes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.730-738
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• 2017

In this study, we investigated the physicochemical properties of coffee brews according to coffee bean grinding grade. We also examined the effect of grinding grade on amounts of volatile flavor compounds. Coffee brew samples were separated using standard sieves (with pore sizes of 850, 600, and $425{\mu}m$), making particle sizes of ground beans as follows: whole bean (control), $850{\mu}m$ or more (coarse), $850{\sim}600{\mu}m$ (medium), $600{\sim}425{\mu}m$ (fine), and $425{\mu}m$ or less (very fine). For each particle size category, pH, total acidity, brown color intensity, chromaticity, total phenolic content, caffeine content, chlorogenic acid content, and total amounts of volatile flavor compounds generated were compared and analyzed. As grinding grade decreased, pH and brown color intensity increased from 4.84 to 5.18 and from 0.257 to 0.284, respectively, whereas total acidity decreased from 0.31 to 0.17%. As grinding grade decreased, the $L^*$ and $a^*$ color values decreased; however, $L^*$ value did not exhibit a significant difference depending on the grinding grade. The $b^*$ value was 15.75 in the very fine size category, which showed the highest yellowness. There was an 11 or higher color difference between the control and ground coffee powder, indicating a remarkable color difference. The total phenolic, caffeine, and chlorogenic acid contents of the coffee brewed from ground beans with a very fine size were 4.54 mg gallic acid equivalent/mL, $733.0{\mu}g/mL$, and $383.7{\mu}g/mL$, respectively, which were high values. The total amounts of volatile compounds in the very fine size category were found to be greater than 100 mg/kg. In this study, we suggest the basis for coffee quality evaluation, which involves evaluating changes in the physicochemical properties and amounts of flavor compounds of coffee relative to the grinding grade of the beans (basic step of coffee extraction).

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.236-242
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• 2017

Chia (Salvia hispanica L.) seed, originated from Central America, is a nutritious food especially rich in dietary fiber and protein. In this study, we investigated the quality and sensory characteristics of Yanggang with chia seed powder (CSP). Red bean paste was replaced with CSP at 0% (Control), 1% (CSP1), 2% (CSP2), 3% (CSP3) and 4% (CSP4). The pH values of chia seed Yanggang tended to decrease from Control (6.84) to CSP4 (6.67); whereas, the moisture contents of Yanggang samples tended to increase. The soluble solid contents of CSP4 were the highest ($3.33^{\circ}Bx$), as compared to the Control which showed the lowest values ($2.77^{\circ}Bx$). In the CSP-added groups, the L-value (lightness), a-value (redness) and b-value (yellowness) were increased, while the ${\Delta}E$ (total color difference) was decreased, as compared to the control group. Hardness and springiness were both increased from control ($49.77g/cm^2$ and 464.80%, respectively) to CSP4 ($72.21g/cm^2$ and 532.43%, respectively). However, cohesiveness decreased from control (47.41%) to CSP4 (37.34%). Chewiness and adhesiveness showed no significant group-wise difference (p<0.05). Total polyphenol content ranged from 7.23 to 10.73 mg GAE/100 g, with a lower ABTS $IC_{50}$ of the CSP-added groups than that of the control group. Samples from the CSP-added as well as Control groups showed no significant differences among all items on the sensory evaluation test, except flavor. The results indicated that CSP had significant effects on the soluble solid contents and texture of Yanggang. Thus, the addition of 2% of CSP is desirable for making Yanggang.

• Food Science and Preservation
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• v.17 no.4
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• pp.471-477
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• 2010

We explored the effects of curing and smoking conditions on the shelf life of Dombaeki (shark meat). Dombaeki cured for 12 h in an aqueous solution containing (per 100 ml) salt 5.6 g, sugar 14 g, and garlic powder 0.6 g, showed the best sensory quality among various samples cured for 0, 3, 6, 9, 12 or 24 hours. The optimum conditions for preparation of smoked Dombaeki (SD) were drying at $60^{\circ}C$ for 30 min, followed by cooking at $80^{\circ}C$ for 30 min and smoking at $65^{\circ}C$ for 40 min, as judged by sensory evaluation of taste, color, flavor, texture, and overall acceptability. The volatile basic nitrogen content of air- or vacuum-packed unsmoked Dombaeki (NSD) was above 20 mg% after storage for either 12 days or 5 weeks. However, the nitrogen contents of air- and vacuum-packed SD were less than 20 mg% after either 21 days or 10 weeks of storage at $10^{\circ}C$. The DPPH free radical-scavenging ability of SD (73.9%) was significantly higher than that of unsmoked meat (4.54%). The total polyphenol content of SD (745.6 g/g) was about 4-fold greater than that of unsmoked meat (179.5 g/g).The viable bacterial count of air- or vacuum-packed unsmoked meat was over $10^6\;CFU/g$ after storage for either 12 days or 5 weeks. However, air- or vacuum-packed SD had counts under $10^4\;CFU/g$ at all storage times tested. Changes in coliform bacterial levels paralleled those of total viable cells. The sensory quality (taste, color, flavor, appearance, texture, and overall acceptability) of SD was significantly better than that of NSD.

• Journal of the Korean Society of Radiology
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• v.3 no.2
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• pp.27-31
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• 2009

Now a days, the Medical X-ray equipments has become digitalized from analog type such as film, cassette to CR, DR. And many scientists are still researching and developing the Medical X-ray equipment. In this study, we used the Bismuth tri-iodide to conversion material for digital X-ray equipments and we couldn't get the satisfying result than previous study, but it opened new possibility to cover the disadvantage of a-Se is high voltage aplly and difficultness of make. In this paper, we use $BiI_3$ powder(99.99%) as x-ray conversion material and make films that have thickness of 200um and the film size is $3cm{\times}3cm$. Also, we deposited an ITO(Indium Tin Oxide) electrode as top electrode and bottom electrode using a Magnetron Sputtering System. To evaluate a characteristics of the produced films, an electrical and structural properties are performed. Through a SEM analysis, we confirmed a surface and component part. And to analyze the electrical properties, darkcurrent, sensitivity and SNR(Signal to Noise Ratio) are measured. Darkcurrent is $1.6nA/cm^2$ and sensitivity is $0.629nC/cm^2$ and this study shows that the electrical properties of x-ray conversion material that made by screen printing method are similar to PVD method or better than that. This results suggest that $BiI_3$ is suitable for a replacement of a-Se because of the reduced manufacture processing and improved yield.

• Journal of the Korean Society of Food Culture
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• v.1 no.3
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• pp.267-278
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• 1986

The evolution of Korean fish fermentation technology was reviewed from the old literatures and the on-going processes were surveyed. The principles involved in the traditional fermentation methods were explained by the recent scientific findings. The fish fermentation technology be classified into two groups; jeot-kal process, where. salt is the only material added to the fish for fermentation, and sik-hae process, where cooked cereals, garlic and red pepper powder are added to the salted fish. A total of 46 kinds of jeot-kal was identified in a survey, depending on the raw materials used. The characteristic feature of Korean jeot-kal process is to produce fermented products which still has original shape after 2-3 months of fermentation to be used for side-dishes of rice meal, as well as fish sauce by keeping these products for longer time (over 6 months) for severe ansymematic hydrolysis to be used for the subingredient of Kimchi (Korean fermented vegetable food). The taste of jeot-kal is formed by the protein hydrolymates due to the action of salt-tolerant Pediococcus, Bacillus, Halobacterlum etc. When the taste of jeot-kal deteriorates, yeasts appear to dominate. In ski-hae fermentation, the safety of preserved fish is kept by the rapid decrease in pH resulting from the acid fermentation of added cereals. The roles of cid forming bacteria and proteloytic bacteria are important. The fermentation is completed in 2 weeks and the excess production of acid during prolonged storage limits the taste acceptability. The fish fermentation technology in Korea stands at important position in Korean food science and technology. since the processes of jeot-kal and soysauce have same root in the principle of microbial proteolysis and the processes of sik-hae and Kimchi in the microbial acid production principles.

• Journal of Conservation Science
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• v.23
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• pp.11-24
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• 2008

A physical characteristics and chemical compositions change by weathering on the granite were examined for the conservation treatment of the Mireuksaji temple stone pagoda. The natural weathered granite was collected from the Mt. Mireuk, and divided into the classification standards based on weathering degrees and strength measured by rock-test hammer. The results from comparison of the strength measured by undestructive rock-test hammer and the strength values converted from ultrasonic velocity showed that each strength measurement value was proportionate. The water absorption of the sample was 1.68 to 0.20%. The F-type of fresh rock was not naturally saturated and the WW-type was naturally saturated but took quite a long time. The water absorption was increased gradually in order of SW-type, the MW-type and the HW-type according to weathering condition. The CW-type samples showed the highest water absorption among the weathered classification samples. Through dyeing test, it was found out that only the feldspar was dyed out of the F-type and the WW-type. The SW-type and the MW-type were distinguished by the fact that plagioclase being dyed. And dyed area was expanded to quartz crack in HW-type and CW-type. Physical change by weathering of the rock-forming minerals could be classified with 3 grades. Through the XRD analysis, albite among the rock-forming mineral showed remarkable decrease. SEM-EDX analysis of the component change in the rock-forming minerals such as biotite, plagioclase, and orthoclase, showed that in case of highly-weathered grade samples compared with fresh samples, contents of the $Al_2O_3$, $K_2O$, $Na_2O$ increase and CaO, MgO decrease in the biotite, the CaO, $K_2O$ increase and $Na_2O$ decrease in the plagioclase, the $Al_2O_3$ a little increase and $K_2O$, $Na_2O$ decrease in the orthoclase. The results of extracted cation analysis using the powder samples of each weathering grade, the CaO, $Na_2O$, $K_2O$ and MgO are highly chemical variations in rock forming minerals and positive variation show high in the weathering grade of the WW-type and CW-type. This research will be used as an importance data to establish a plan for conservation treatment of composed stone in the Mireuksaji temple stone pagoda.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.3
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• pp.281-290
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• 2018

In order to understand the long-term behavior of radionuclides in granite environments, geochemical behavior characteristics of uranium in granitic host rock of KURT (KAERI Underground Research Tunnel) were investigated by dissolution experiment with different reaction time and solutions. In the dissolution experiment, significantly increased dissolution levels of uranium from granite powder samples were identified during the reaction time of 0~10 days for reaction solutions ($UD-CO_3$ and UD-Bg) containing a large amount of $CO_3{^{2-}}$. On the other hand, significantly increased dissolution levels of uranium were also identified for reaction solutions containing Na and Ca after 60 days. Dissolution of uranium continuously increased in reaction solutions of $UD-CO_3$ ($44.61{\mu}g{\cdot}L^{-1}$), UD-Bg ($41.01{\mu}g{\cdot}L^{-1}$), UD-Na ($26.87{\mu}g{\cdot}L^{-1}$), UD-Ca ($20.26{\mu}g{\cdot}L^{-1}$), UD-CaSi ($17.03{\mu}g{\cdot}L^{-1}$), and UD-Si ($10.47{\mu}g{\cdot}L^{-1}$) in the experimental period of ~270 days. However, after day 270, dissolution of uranium showed a decreasing tendency. This is thought to have occurred because existing uranium in granite samples reached the limit of dissolution by interaction with reaction solutions. Concentrations of dissolved uranium and points of maximum concentration value were found to differ depending on the $CO_3{^{2-}}$ presence in the mixed reaction solution and on the geochemical type of the water. It is estimated that differences in the reaction rate between the granite sample and the reaction solution are due to the influence of dissolved ions in the reaction solution.

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.521-532
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• 2006

An in vitro study was conducted to examine the effect of addition level of carbohydrates on fermentation characteristics, and bio-hydrogenation of unsaturated fatty acids by mixed rumen bacteria when incubated with soybean oil or flaxseed oil. Four levels(0%, 0.3%, 0.6% and 0.9%, w/v) of the mixed carbohydrates(glucose, cellobiose, soluble starch, 1:1:1, in weight basis) and oil sources(soybean or flaxseed oil, 60mg in 150ml culture solution) were added to the mixed solution of strained rumen fluid with artificial saliva(1:4, v/v), and incubated anaerobically for 12 hours at 39℃. pH and ammonia-N concentration were lower by increasing the substrate levels at all incubation periods(P<0.05～P<0.001). The propionate proportion increased(P<0.001), but acetic acid and butyric acid decreased(P<0.001) with the substrate level at 6 and 12 h incubations. Oil sources did not influence the proportions of individual VFA. At the end of incubation, the proportions of C18:0(P<0.01), C18:1(P<0.001) and trans-11C-18:1(P<0.01) were reduced but those of C18:2(P<0.001) and C18:3(P<0.01) were enhanced by the addition of flaxseed oil compared to addition of soybean oil. The proportions of C18:0 and total CLA were reduced(P<0.01) but those of trans-11-C18: (P<0.05) and C18:2(P<0.01) were increased with the substrate level when incubated with soybean oil or flaxseed oil. There were interactions(P<0.05) in the proportions of C18:1, C18:2 and C18:3(P<0.01) between oil source and substrate level. The proportions of cis-9, trans-11-CLA and trans-10, cis-12-CLA tended to reduce with substrate level, although there was no significant difference between treatments.