• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.115-130
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• 2004

Plant-based cultural assets using straw and grass as household goods of our people's have been used as indispensable tools for practical living for a very long time. However, only a limited number of artifacts were unearthed so far due to tile fragility of the material. For this reason, research on plant-based cultural properties had close to no progress, and the appropriateness of the PEG method, high-grade alcohol method, alcohol--ether-resin method, and Paraloid B-72 used in preserving plant-based cultural properties has not been sufficiently investigated. Therefore, this study examined the weight change rate by applying the methods of Primal MC-76 and vacuum freeze-drying used mostly as a earth-layer hardening material among PEG and acrylic resin, which are applied widely for preservation of waterlogged archaeological wood, as a means to preserve plant-based cultural properties along with the examination of the subject material, and an experiment was also performed on moisture absorption. The findings as a result were, first, the plant-based material being studied was found to be Typha (Typha orientalis Presl). Secondly, the weight change experiment applying $PEG\#400$ and $PEG\#4000$ confirmed a steady increase of weight if PEG -2Step is used for treatment. Third, in preserving all subject materials with soil, treatment with $PEG\#4000$, Primal MC-76, and vacuum freeze-drying showed that tile vacuum freeze-drying method resulted in the largest or $20\%$ reduction in weight, while Primal MC-76 resulted in $18\%$ and $PEG\#4000$ in $8\%$ of weight reduction. It was concluded that, considering the stability of soil measurement, this came to be because resin permeation was carried out along with tile drying process. Fourth, the weight changes were found to be around $10\%$ in various humidity conditions after the preservation treatment. The greatest weight change rate was seen in the case of $PEG\#4000$, particularly having chemicals gush out in a high humidity (RH $84\%$ or higher) environment. In the case of Primal MC-76 and vacuum freeze-drying methods, $6\~8\%$ weight changes were detected, and the lowest weight change was found in the case of the vacuum freeze-drying method. Fifth, as for color changes after treatment, blackening occurred most strongly with $PEG\#4000$, while Primal MC-76 and vacuum freeze-drying manifested colors closest to dry straw or grass. However, the texture of straw was not very evident in the case of Primal MC-76, due to a glossy surface, but vacuum freeze-drying was found to offer tile best result in terms of texture. Putting together the results of the above experiments, vacuum freeze-drying presented after being treated with PEG2-Step the most stabilized changes in weight, while it offered the smallest change in color as well.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.56-61
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• 1985

The mass balances of calcium salts during the manufacturing processes of Tofu were established by conductometric method and chemical analysis method. During the manufacturing processes of soy milk and Tofu, 66% of solid and 63% of calcium was transfered from soy-bean to the soy milk, and 47.8% of total solid from soybean was transfered to the Tofu, respectively. When the $CaCl_2$ was used as coagulant, calcium contents in Tofu $(Y_{Tofu},\;mg{\cdot}Ca/g{\cdot}Tofu,\;wet\;basis)$ and drained solution $(Y_{drained\;soln},\;mg{\cdot}Ca/ml{\cdot}drained\;soln.)$ were linearly increased with the amounts of $CaCl_2(C,g{\cdot}CaCl_2/ml{\cdot}soy\;milk)$ added in soy milk, and correlative equations between them were obtained as $Y_{Tofu}=0.3369\;C+1.2689$ for Tofu$(moisture\;content:\;81.5{\pm}0.5%)$ with r=0.9898, and $Y_{drained\;soln}= 0.2899C+0.0399$ for drained solution with r= 0.9991. It was proved that conductometric method was reasonably applicable to the measurement of calcium contents of the products from every processes of Tofu manufacture except soy-bean. However the conductometric method was not recomendable in the case of $CaSO_4$ as coagulant due to its low solubility ana uneven distribution in soy milk and Tofu tissue.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.90-99
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• 2014

Tarak is our own traditional fermented milk, which is made from lactic acid fermentation by using makgeolli as inoculum for milk or fermented by using Tarak that had already made. we made our own traditional fermented milk and Tarak Pudding by the traditional fermented milk, and then, we investigated the quality characteristics of Tarak Pudding on the addition rates of Tarak. As a result, the more the amount of Tarak, the more the contents of crude protein, crude fat and crude ash of Tarak Pudding according to the percentage of addition of Tarak meaningfully, except for its moisture content (p<0.05). While the pH decreased with more Tarak, the acidity significantly increased. In the case of sugar content, TP 1, 2, and 3 were higher than the control group, and TP 4 showed the higher sugar content(p<0.05). As the result of measurement of chromaticity of Tarak Pudding, the L value of the control group was 38.80. However, it increased with more addition of Tarak, while a value decreased. For the b value, it significantly increased with more Tarak. In the measure of texture, there were significant differences between the control group and the samples in hardness, springiness, cohesiveness, chewiness, and adhesiveness (p<0.05). The sensory evaluation result showed that there were meaningful differences among the samples in their appearance, taste, flavor, texture and overall acceptance. However, due to distinctive sour and odor of Tarak, TP 3 (75% addition) than TP 4 (100% addition) was considered to be desirable.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1035-1040
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• 2005

This study was conducted to investigate the surface spraying effect of materials on the rheological properties of frozen starch with microwave heating. Microwave helps reduce cooking time by high temperature, but swiftly snatches moisture from foods such as frozen starches (buns and noodles etc) and makes surface of foods harder. Four types of maltodextrin materials have been prepared for different concentration solutions and sprayed on surface doughs of sheet type. Sprayed dough samples were Quickly frozen at $-70^{\circ}C$ and wrapped with polypropylene film. All the treated samples were kept at 0, -20 and $-50^{\circ}C$, and then taken out periodically for measurement of the quality during storage. The quality attributes evaluated after heating with microwave energy include sensory quality retrogradation, texture, surface color and microstructure. The quality of frozen starches deteriorated with long term storage even at low temperatures of -20 and $-50^{\circ}C$, and the spray materials were found to improve the textural and physical properties of frozen starches in the microwave heating. Particularly, maltodextrin with D.E value of $9\~12$ had the most desirable effects of quality improvement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.342-347
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• 2008

This study was to develop processed food with the addition of onion powder by investigating the quality characteristics of cookies with various levels (0, 1, 3, 5 and 10%) of hot-air dried yellow and red onion powder. Moisture (11.59%), crude protein (4.56%), and crude ash contents (3.83%) of yellow onion powder showed higher value than red onion powder. Hot-air dried yellow onion powder showed a higher L and b value as compared with red onion powder because of the unique color of the onion. Browning index was lower in red onion powder than red onion powder. Phenolic contents of yellow onion powder appeared to be higher than that of red onion powder. Total sugar contents were higher in red onion powder than yellow onion powder. The pH of the dough significantly decreased with increase of added onion powder contents. Dough density of control had a significantly higher value than the other samples. Hardness measurement showed significantly higher value with increasing additions of onion powder contents; added red onion powder samples were the most highest when compared to added yellow onion powder samples. Results of sensory characteristics showed significantly higher smell, taste, texture and overall acceptability with 3% added red onion sample. Quality characteristics of 5% added yellow onion powder sample and 3% added red onion powder sample indicated possibilities for developments of onion cookies.

• Journal of the Korean Chemical Society
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• v.61 no.6
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• pp.346-351
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• 2017

This study was planned considering the chain length, hydrophilicity, and hydrophobicity of the additives to be used in the polymerization, while various ophthalmic lenses that use various additives with similar water contents were manufactured before their optical and physical properties were compared and analyzed. With regard to the additives required for manufacturing high-, medium-, and low-water content lens groups, HEA (hydroxyethyl acrylate), PVP (polyvinylpyrrolidone), and NMV(N-methyl-N-vinylacetamide) were used as additives for preparing the high-water content lens group, HEMA(2-hydroxyethyl methacrylate), HPMA(hydroxypropyl methacrylate) and BD(1,4-butanediol) were used for the medium-water content lens group. For the low-water content lens group, BMA(buthyl methacrylate), BDDA(1,4-butanediol diacrylate), and Bis-GMA(bisphenol A glycerolate diacrylate) were used, respectively. The average water content of HEA was 40.14%; that of PVP, 39.63%; and that of NMV, 40.52%. The mean of water content was 35.92% for HEMA, 35.74% for BD, and 34.62% for HPMA. For the low-water content lens group, the mean of water content was 26.69% for BMA, 27.76% for BDDA, and 26.14% for Bis-GMA. With regard to the results of the water content measurement using a moisture analyzer, the average water content of the high-water content lens group was 41.34% for HEA, 42.62% for PVP, and 42.73% for NMV. Finally, for the low-water content lens group, the average water content was 28.62% for BMA, 28.82% for BDDA, and 28.32% for Bis-GMA. The measurements of the water contents of the lenses using the two methods showed that the water content and refractive index of the lenses were similar in all the lens groups. The measurements of the contact angles, however, showed a different wettability value for each lens with a similar water content. Also, the change tendency of the lens curvature according to the change of time showed that the change amount became larger and the recovery time became longer from the lens samples with a lower water content to those with a higher water content. Based on these results that will be helpful for the study of ophthalmic lenses.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.413-420
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• 2011

An experiment was conducted to suggest the road pavement material combining wooden chip crushed from little useful roots and branches from logging sites or wood waste from construction sites with urethane resin. For the specimen, the mass ratio of urethane resin to construction wood waste chip/lumber waster chip was set to three different levels of 0.5, 0.75, and 1.0, which was measured, mixed with mixer, and molded; 7 days after, tensile strength test, elasticity test using golf balls and steel balls, permeability coefficient measurement, and flammability test were executed. As the result, the tensile strength of the specimen at the dry state in the air exhibited the range of 0.2-1.1MPa, and there was no change after 7 days of aging. When submerged in water, however, the strength was partially diminished; the diminishing rate was greater for less urethane resin usage, and therefore it appears desirable to set the mass ratio of resin to the wood waste chip over 0.75 to consider the moisture intrusion by precipitation and such. As the result of elasticity test, the GB and SB coefficients of the specimen using wood waste chips and urethane resin were measured to be low at below 20%, exhibiting excellent elasticity as road pavement material. Also, the permeability coefficient was over 0.5mm/sec for specimens of all combinations, exceeding the standard value required after construction for permeable pavement material, and the flammability of wood-type pavement material was evaluated to have no practical issues.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.121-141
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• 2017

The thermal analysis of an underground power conduit for electrical cables is essential to determine their current capacity with an increasing number of demands for high-voltage underground cables. The temperature rises around a buried cable, caused by excessive heat dissipation, may increase considerably the thermal resistance of the cables, leading to the danger of "thermal runaway" or damaging to insulators. It is a key design factor to develop the mechanism on thermal behavior of backfilling materials for underground power conduits. With a full-scale field test, a numerical model was developed to estimate the temperature change as well as the thermal resistance existing between an underground power conduit and backfill materials. In comparison with the field test, the numerical model for analyzing thermal behavior depending on density, moisture content and soil constituents is verified by the one-year-long field measurement.

• Food Science and Preservation
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• v.22 no.1
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• pp.56-62
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• 2015

In this study, the quality characteristics of different drying methods of Aronia melanocarpa, which contains large amounts of bioactive substances, were investigated for the improvement of their practical use. During the drying period, the weight reduction was the highest with vacuum freeze drying (81.6%). The water content was reduced to the maximum level when vacuum freeze-drying was used. With regard to the color value measurement results, there were no significant differences in the $L^*$ value. Values of $a^*$ and $b^*$ were increased in vacuum freeze drying and cold air drying, but decreased in hot air drying. The hardness was increased dramatically after 36 hours of hot air drying, while with cold air drying, it increased slowly until 132 hr and increased rapidly after 132 hr. The dried yield was the highest with cold air drying (24.2%). As for the general component analysis results of Aronia melanocarpa, the moisture content was the lowest, and the crude protein and crude fat contents were the highest with vacuum freeze drying. No difference in pH value was shown among the dried Aronia melanocarpa obtained from the different drying methods, but the sugar content was the highest with vacuum freeze drying. The mineral content was the highest with cold air drying, and K, Ca, Mg, and Na were the major minerals. The free sugar content of dried Aronia melanocarpa was found to be 5.92~20.59 g/100 g, and the highest free sugar content was found with vaccum freeze drying.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.181-186
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• 2000

This study was conducted to investigate various components and aflatoxin of sigumjang during fermentation time. The contents of moisture were decreased during fermentation time. The contents of protein, fat and ash were $19.8{\sim}20.8%,\;1.3{\sim}1.6%$ and $3.1{\sim}3.2%$, respectively. The pH was gradually acidized. The result of measurement of surface color showed: L-value, $29.45{\sim}30.94\;a-value,\;+3.01{\sim}+3.63;\;b-value,\;+5.39{\sim}+6.34$. Aflatoxin was not detected during fermentation. Among 81 kinds of flavor components identified in sigumjang, esters was most in number followed by acids, aldehydes, alcohols and phenols.