• Toxicological Research
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• v.26 no.1
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• pp.29-35
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• 2010

The present study was conducted to investigate the antimutagenic potential of the methanolic extract from the leaves of sweet potato (Ipomea batatas, IB) with the SOS chromotest (umu test) and Salmonella typhimurium TA 98 and TA 100. The anticarcinogenic effects were also studied by calculation of the $IC_{50}$ on human cancer cell lines and investigating the function of gap junction in rat liver epithelial cells. The IB extract inhibited dose-dependently the ${\beta}$-galactosidase activity induced spontaneously at concentration of more than 200 mg/ml in S. typhimurium TA 1535/pSK 1002, and decreased significantly (p < 0.01) the ${\beta}$-galactosidase activities induced by mutagen 6-chloro-9-[3-(2-chloroethylamino)proylamino]-2-methoxyacridine dihydrochloride (ICR) at dose of more than 0.4 mg/0.1 ml. The IB extract showed no effect on the spontaneous reversions of S. typhimurium TA 98 and 100 but benzo(${\alpha}$)pyrene (BaP)-stimulated reversions were decreased dose-dependently (p < 0.01) at the concentration of more than 100 mg/ml. The $IC_{50}$ value of stomach cancer cells was lower than that of normal rat liver epithelial cells, but the values of colon and uterine cancer cell lines were similar to those of normal rat liver epithelial cells. The transfer of dye through gap junctions was not affected by treatment of the IB extracts at any concentration during treatment periods. The simultaneously treatment of IB extract and 12-O-tetradecanoylphorbol-13-acetate (TPA) effectively prevented the inhibition of dye transfer induced by TPA 1 hour after treatment at all exposed concentrations. The number of gap junctions was significantly (p < 0.01) increased by the treatment with IB extract at concentrations of more than 40 ${\mu}g$/ml. The inhibition of the expression of gap junction proteins by TPA (0.01 ${\mu}g$/ml) was recovered dose dependently by the simultaneous treatment of IB extracts. Our data suggest that Ipomea batatas has antimutagenic and anticarcionogenic activity in vitro.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.356-360
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• 2007

Fuel sloshing in a vehicle fuel tank generates a reluctant low frequency noise, called slosh noise. To reduce slosh noise, whilst many approaches have used the Computational Fluid Dynamics method to first identify fuel behavior in a fuel tank, this paper applies the Transfer Path Analysis method. It is to find contribution of each transfer path from noise transfer function, vibration transfer function and acceleration. Then the final goal is to attenuate slosh noise by controlling them. To this aim, two types of models are studied. One is the decoupled model in which some of connection points of the fuel tank with the vehicle underbody are separated. The other is the modified model which is created by changing noise transfer function and acceleration from the original model. The analysis and validation test results show that the transfer path analysis can be an approach to enhancing slosh noise.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.8
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• pp.766-770
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• 2007

Fuel sloshing in a vehicle fuel tank generates a reluctant low frequency noise, called slosh noise. To reduce slosh noise, whilst many approaches have used the Computational Fluid Dynamics method to first identify fuel behavior in a fuel tank, this paper applies the Transfer Path Analysis method. It is to find contribution of each transfer path from noise transfer function, vibration transfer function and acceleration. Then the final goal is to attenuate slosh noise by controlling them. To this aim, two types of models are studied. One is the decoupled model in which some of connection points of the fuel tank with the vehicle underbody are separated. The other is the modified model which is created by changing noise transfer function and acceleration from the original model. The analysis and validation test results show that the transfer path analysis can be an approach to enhancing slosh noise.

• Culinary science and hospitality research
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• v.21 no.2
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• pp.230-242
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• 2015

The purpose of this study is to investigate the quality characteristics of bread added with different levels of Pu'er tea. The overall effects of Pu'er tea on white pan bread were examined through mixograph, fermentation rates, TPA, volumes, crumbScan, color value, moisture content, and sensory evaluation. The result of the mixogram showed that all samples were found to be adequate between 3 and 5 minutes of peak time and their peak values were at 60%. Among the samples, PRaw15 had the highest fermentation rate, and it showed the lowest hardness in TPA. In addition, PRaw15 had the highest specific volume and moisture content. The results of the crumbScan showed that there were significant differences in crumb fineness, volume, and thickness between the samples. Color value also exhibited significant differences between the samples. The acceptance test showed that PRipe15 had the best overall acceptance. In conclusion, Pu'er tea affects the quality of dough and bread. Therefore, Pu'er tea could be added when bread is baked for improved health and better quality of the bread.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.117-133
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• 2016

This study was to investigate the quality characteristics of sourdough bread made with 4 kinds of kamut sour starter. Kamut sour starters were made according to dough yield of sour starter and yeast adding on sour starter. We exmanined pH level, fermentation rate, specific volume, CrumbScan, moisture content, color value, texture analyzer, shelf-life test and sensory evaluation for observing quality characteristics of sourdough bread. From the results of pH measurement, kamut sourdough breads had lower pH value in dough and crumb pH than CON. In the experiment of dough's fermentation rate, CON had the rapidest fermentation rate among the samples initially, but the experimental groups also expanded as much as CON grew in spite of its slow fermentation. Specific volume and CrumbScan results suggested that CON had the largest volume. In addition, CM and TM had smaller volume than Pool and Biga. The sample that had the highest moisture content was Pool because its sour starter had the most amount of water. In color value test, CON had lighter crumb and crust color than other specimens. As a result of the TPA and shelf-life tests, CON had the softest hardness after 24 hours. However, Pool had similar hardness with CON after 72 hours. The result of the acceptance test of sourdough breads indicated that people prefered Pool and Biga to TM and CM. Difference test showed similar results with prior experiments. As the final outcome, Poolish was chosen as the optimal formula for kamut sour starter.

• Culinary science and hospitality research
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• v.19 no.4
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• pp.147-160
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• 2013

This research investigates the quality characteristics of bread added with honey. The overall effects of honey on white pan bread were examined in terms of mixograph, fermentation rates, pH levels, TPA, colorimeter, water activity, hardness and moisture content of bread through different storage periods(1, 2, 3 days) using sensory evaluation. According to mixograph, all the samples were found to be proper between 3 and 5 minutes of peak time and their peak values were at the level of 60%. Also, HL100 had the highest fermentation rate and fermentation persistence from 60 min to 135 min. HL100 showed the lowest pH level in ingredient, dough, fermentation and crumb, and the highest specific volume. TPA analysis showed that HL100 had the lowest hardness and the highest springiness of all. And HL100 was the lowest in hardness(i.e. highest in softness) and had the highest moisture content after storage of 72 hours. Preference test showed that HL100 got the best texture, flavor, mouth feel, taste and overall acceptance. In these results of experiment, honey affects the quality of dough and bread, and liquid honey could be used as a substitute for sugar in breadmaking.

• Culinary science and hospitality research
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• v.21 no.3
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• pp.1-12
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• 2015

The purpose of this study was to investigate the quality characteristics of muffins prepared with saccharin. The effect of saccharin was evaluated in terms of height, weight, volume, specific volume, baking loss rate, image analysis, color, texture, moisture contents and acceptance test. Height, weight, volume and specific volume of muffins increased with the addition of saccharin. The baking loss rate of the samples containing saccharin was lower than those of the control group. Crust thickness of muffins containing saccharin evaluated with crumbScan decreased as the content of saccharin increased. Lightness of crust decreased significantly as contents of saccharin decreased, whereas lightness of crumb increased. Control without saccharin showed the most hardness by TPA. During storage, moisture contents increased significantly as the amount of saccharin increased. According to the acceptance test, muffins with saccharin exhibited higher scores than muffins with sugar except for color of crust and flavor. In particular, Samples 1 and 2 had the highest scores. Based on the above results, the addition of saccharin would be appropriate for making muffins.

• Food Engineering Progress
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• v.23 no.3
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• pp.217-222
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• 2019

The purpose of this study is to investigate the effect of ultra-fine powder kelp powder as a natural food additive for fast rehydration on the quality of freeze-dried fish cake noodle with soft and elastic texture properties during or after cooking. The average moisture content and water activity ranges of freeze-dried fish cake noodle were 3.71±0.12% (dry basis) and 0.185-0.332, respectively. The water activity of freeze-dried fish cake noodle decreased upon increasing the kelp powder content at the same moisture content. The rehydration ratios of fish cake noodle with 1, 3, and 5% (w/w) of kelp powder were 1.39, 1.49, and 1.77 g water/g solid, respectively. The hardness of the 5% (w/w) kelp powder-enhanced fish cake noodle after rehydration had the lowest value among the three samples upon using a texture profile analysis test (TPA). In the sensory hedonic test results, 5% (w/w) kelp powder added to fish cake noodle after rehydration produced the highest values in texture, flavor, and overall quality.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.56.4-57
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• 2017

The Schwarzschild-Chang off-axis telescope is a "linear astigmatism-free" confocal system. The telescope comprises two pieces of aluminum-alloy freeform mirrors that are fabricated with diamond turning machine (DTM) process. We designed optomechanical structures where optical components in the telescope system can be adjustable on a linear stage. Optomechanical deformation caused by the weight of system itself and its temperature variation is analyzed by the finite element analysis (FEA). The results show that the deformation is estimated in the tolerance range. For the optic-axis alignment of telescope system, three-point alignment (TPA) method is chosen. The TPA method uses three parallel lasers and a plane mirror. Point source images were taken from collimated light and field observation. The performance of optical system was tested by point spread function and aberration measurement of the point sources.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.425-433
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• 1999

Dr. Youn-Sic Chun and coworkers invented the new machine for getting information about the relative effectiveness of the orthodontic appliances and we named it Calorific machine. The author and colleagues used this machine to compare with tooth moving mechanism by 3 types of the insertion method of precision-TPA for derotating the posterior teeth. We measured the distance of tooth movement and found out the rotational center on the occlusal X-ray film and the tooth movement on the occlusogram and then processed paired t-test by SAS program, The results were as follows : 1. In the intermolar width, the mesial insertion method showed the loss oi distance, and the other methods(-distal insertion method, mesial expansion method-) showed the increase of distance. 2. In the arch length, the distal insertion method was exhibited as most recommandable way for increasing the arch length .3. The rotation center of the mesial insertion method for derotating the molar, was located between mesial pit and central pit of the lower End molar. And, in the distal insertion method, it was located between distal pit and distolingual cusp, and in the mesial expansion method was located at distal pit.