• International Journal of Highway Engineering
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• v.18 no.1
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• pp.13-21
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• 2016

PURPOSES : In this study, we analyzed the compressive strength characteristics of lean base concrete in relation to changes in the outdoor temperature after analyzing the cold and hot weather temperature standards and calculated the minimum and maximum temperatures when pouring concrete. We examined the rate of strength development of lean base concrete in relation to the temperature change and derived an appropriate analysis formula for FRC base structures by assigning the accumulated strength data and existing maturity formula. METHODS : We measured the strength changes at three curing temperatures (5, 20, and $35^{\circ}C$) by curing the concrete in a temperature range that covered the lowest temperature of the cold period, $5^{\circ}C$, to the highest temperature of the hot period, $35^{\circ}C$. We assigned the general lean concrete and FRC as test variables. A strength test was planned to measure the strength after 3, 5, 7, 14, and 28 days. RESULTS : According to the results of compressive strength tests of plain concrete and FRC in relation to curing temperature, the plain concrete had a compressive strength greater than 5 MPa at all curing temperatures on day 5 and satisfied the lean concrete standard. In the case of FRC, because the initial strength was substantially reduced as a result of a 30% substitution of fly ash, it did not satisfy the strength standard of 5 MPa when it was cured at $5^{\circ}C$ on day 7. In addition, because the fly ash in the FRC caused a Pozzolanic reaction with the progress into late age, the amount of strength development increased. In the case of a curing temperature of $20^{\circ}C$, the FRC strength was about 66% on day 3 compared with the plain concrete, but it is increased to about 77% on day 28. In the case of a curing temperature of $35^{\circ}C$, the FRC strength development rate was about 63% on day 3 compared with the plain concrete, but it increased to about 88% on day 28. CONCLUSIONS : We derived a strength analysis formula using the maturity temperatures with all the strength data and presented the point in time when it reached the base concrete standard, which was 5 MPa for each air temperature. We believe that our findings could be utilized as a reference in the construction of base concrete for a site during a cold or hot weather period.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.11
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• pp.925-932
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• 2017

In this study, the analysis of plate under torsion was carried out according to stacking angle at the unidirectional carbon fiber reinforced plastic(UD CFRP) among composite materials. In case of UD CFRP, the material property due to stacking angle becomes different. Also, the stacking angles were designated to 15°, 30°, 45°, 60°, 75° and 90° at the study models. The notch hole was applied at the center part by supposing that rivet or hole was used. The analysis method was used by applying the experimental method at ISO 15310. Two jigs were fixed at the lower part and two jigs were descending at the upper part. As seen by the analysis result values at this study, the shear stress happening at the fracture part was seen with the lowest value in case of the stacking angle of 45°. It is known that the case of the stacking angle of 45°has the structural safety and durability higher than those of the other stacking angles when the torsion applies. It is thought that this result can be applied to the data of basis which can be devoted to the durability when the torsion is applied at CFRP plate.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.2
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• pp.59-66
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• 2008

In the construction site, to improve the man-dependent form work, non-stripping form has been studied but the developed non-stripping form was hard to applied with respect to the cost, form size and performance. This study is for evaluating the adaptability of the developed non-stripping form named as high performance permanent form (HPPF). To do this, the analytical approach and parametric study were performed based on the research for fundamental material characteristic of the HPPF. The target concrete structure is a wall structure because of its effectiveness of HPPF. To evaluate the structural efficiency of the HPPF applied wall structure, FEM analysis was performed to decide the maximum placing height at one time then it was applied to design the wall structure. In the result of the analysis, the HPPF applied wall structure showed the lots of advantages that it can reduce the cost resulted from reducing concrete and steel rebar even if it has same structural performance to the conventional concrete wall structure with same dimension. With this analysis result, it can be evaluated that the HPPF applied concrete structure can be a concrete structure with the long term durability in site.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.2
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• pp.135-139
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• 2018

This study was conducted to evaluate the forage production and feed value of Sasa borealis (S. borealis) in Jeju Island in order to improve the utilization of Sasa borealis and to help mitigate the problem of reduced plant species diversity caused by S. borealis in Hanlla Mountain. To investigate the forage production, three quadrat structures were installed in the S. borealis natural community in the middle part of Hanlla Mountain. From May to October 2017, S. borealis in quadrats was cut at a fixed time of each month, and then forage production and regenerated acidity per kg/ha were evaluated. For the evaluation of feed value, compositional analysis was performed on the monthly samples. In vitro digestion experiments were carried out using cannula mounted Hanwoo. In vitro neutral detergent fiber digestibility(IVNDFD) and in vitro acid detergent fiber digestibility(IVADFD) were measured after the experiment. Forage production of S. borealis showed relatively good regeneration ability in May and June, but the regeneration ability decreased as the cutting was repeated. In order to use S. borealis as a forage, it is considered efficient to feed black goats with good fiber decomposition or horses good palatability to S. borealis and relatively good digestibility.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.807-819
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• 2020

The aim of this study was to investigate the anatomical characteristics of Quercus mongolica infested by oak wilt disease. To analysis the anatomical characteristics of the wood specimens infested by the oak wilt, the anatomical structures of an infected wood, a dead wood, and sound wood were observed at 10-year-old intervals from 10 to 50 annual rings using both an optical and a scanning electron microscope. The fiber length was measured in units of 5 annual rings from the pith, and the diameter of the vessel element and the ratio of the vessel including the tyloses were measured for each 10 annual ring. In the cross section, on the infected and dead wood specimens, mycelium was also observed with the tyloses in the vessel. There was no signification difference between the wood specimens in the fiber length and the vessel diameter of the vessel element. The fiber length was not difference after 20-30 annual rings which is a part of juvenile wood. The average of the vessel ratio including tyloses in the infected wood was the highest. Especially, the ratio of tyloses was the highest 40-50 annual rings in the infected wood and the dead wood. Therefore, the large difference between the infested wood by oak wilt and the sound wood was the ratio of tyloses. This result can be used as a basic data to utilize the infested wood.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1634-1639
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• 2010

The purpose of this study is to determine the possibility of using Kalopanax pictus leaf as natural health food source. The contents of proximate and antioxidative nutrients of Kalopanax pictus leaf were measured. The contents of carbohydrate, crude protein, crude lipid and ash were 41.42%, 45.23%, 3.29% and 10.07%, respectively. The calories of Kalopanax pictus leaf was 401.52 kcal/100 g and total dietary fiber was 30.37%. The percentages of water soluble dietary fiber to insoluble dietary fiber were 9.16% and 21.21%, respectively. The protein contained a total of 18 different kinds of amino acids. The contents of essential and non-essential amino acids were 10.51 g/100 g and 17.69 g/100 g. The K was the largest mineral followed by P, Ca, and Mg, which means Kalopanax pictus leaf is alkali material. The contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were 1.56 g/100 g, 0.11 g/100 g and 1.84 g/100 g, respectively. The antioxidant activity of 70% ethanol extract and fractions of the Kalopanax pictus leaf has been determined by the scavenging of the stable radical DPPH; the result showed that the ethyl acetate fraction was the most active, as the amount required for 50% reduction of DPPH after 30 mins ($RC_{50}$) was $105.7\;{\mu}g$, followed by 70% ethanol extract ($247.3\;{\mu}g$), hexane fraction ($120.7\;{\mu}g$), chloroform ($107.3\;{\mu}g$), butanol fraction ($110.1\;{\mu}g$) and aqueous fraction ($491.9\;{\mu}g$).

• Korean journal of food and cookery science
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• v.10 no.4
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• pp.363-368
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• 1994

The study was carried out to investigate the proximate composition, amino acids, dietary fiber, ascorbic acid and minerals contents of seven edible wild vegetables; an Evening Primerose($S_1$), a Spiderwort($S_2$), the Flower of a Convolvulus($S_3$), So Ru Jaeng Yi($S_4$), Shoe Bi Rum($S_5$), O Yi Pul($S_6$), Jip Sean Na Mul($S_7$). Results as summarized as follows: 1. The moisture contents of samples were determined as 64.43~88.30% The largest amount of them was contained in a Spiderwort($S_2$) and the smallest was in a Jip Sean Na Mul($S_7$), 2. The crude protein contents of samples were determined as 2.71~8.10%. The largest amount of them was contained in a O Yi Pul($S_8$), the smallest was in the Spiderwort($S_z$). 3. A relatively large amount of total amino acids were determined in samples. The abundant amino acids existed in the samples were Glutamic acid(10%), Lysine(8%), Leucine(8%) and the content of Methionine was very low. The highest level of them was found in the Convolvulus($S_3$), 4,419.6 mg% and the lowest was Shoe Bi Rum($S_5$), 2,393.1 mg% 4. The Ascorbic acid contents of samples was determined as 55.99~31.8O mg. The highest level of them was found in the Jip Sean Na Mul($S_7$) and the smallest was in the Primerose($S_1$) 5. The mineral contents of samples were determined. A relatively large amount of K, Ca and Mg were found in the samples. Especially the level of Iron was higher than that of any other vegetables. 6. The contents of dietary fiber were determined as 31.8~79.9%. The highest level of them was found in the Convolvulus($S_3$) and the lowest was in the Spiderwort($S_2$). The highest level of them was found in the Convolvulus($S_3$) and the lowest was in the Spiderwort($S_2$). From the above mention, we can say that the contents of protein, fat, fiber, total amino acids and iron were abundant in wild grasses than that of any other wild and cultured vegetables. The contents of ascorbic acid, potassium, calcium and magnesium were similar and the moisture is significantly low compared with any other vegetables.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.166-176
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• 2009

Eighteen Korean chestnut cultivars were collected from various places and the proximate compositions, dietary fiber, amino acid and free sugar contents in three parts (whole kernel, white kernel, yellow kernel) of eighteen Korean chestnut cultivars were analyzed. The white kernel of Chukfa and the yellow kernel of Ipyung contained the highest amount of moisture and crude protein, respectively. Carbohydrate content of whole kernel showed a range of $30.8{\sim}52.0%$ and crude ash content of whole kernel showed a range of $0.9{\sim}1.8%$. The amount of crude lipid was the highest in Byunggo. The amount of dietary fiber in Kwangeun, Daebo, Parkmi 1 ho, Yooma and Pyeonggi were higher than that of other Korean chestnut cultivars. Seventeen amino acids were detected. Major amino acids of the various chestnuts were aspartic acid and leucine. The amount of amino acids was higher in Ichui, Ipyung and Pyeonggi but was lower in Dantaek and Sandae than that of other samples. The major free sugar in the chestnuts was glucose. The free sugar amount of yellow kernels was higher than the white kernels.

• Journal of Pharmaceutical Investigation
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• v.39 no.1
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• pp.29-36
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• 2009

Since the quality of final products is significantly affected by the homogeneity of powder mixture, the powder blending process has been regarded as one of the critical pharmaceutical unit processes, especially for solid dosage forms. Accordingly, the monitoring to determine a blending process' end-point based on a faster and more accurate in-line/on-line analysis has attracted enormous attentions recently. Among various analytical tools, NIR (near-infrared) spectroscopy has been extensively studied for PAT (process analytical technology) system due to its many advantages. In this study, NIR spectroscopy was employed with an optical fiber probe for the in-line monitoring of fluid-bed blending process. The position of the probe, the ratio of binary powder mixture, the powder size differential and the back-flush period of the shaking bag were examined as principal process parameters. During the blending process of lactose and mannitol powders, NIR spectra were collected, corrected, calibrated and analyzed using MSC and PLS method, respectively. The probe position was optimized. A reasonable end-point was predicted as 1,500 seconds based on 5% RSD value. As a consequence, it was demonstrated that the blending process using a fluid-bed processor has several advantages over other methods, and the application of NIRS with an optical fiber probe as PAT system for a fluid-bed blending process could be high feasible.

• Journal of the Korean Wood Science and Technology
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• v.33 no.3 s.131
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• pp.45-52
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• 2005

This research was performed to evaluate adsorption behavior of woody charcoals obtained from wood powder, fiber and bark of spruce (Abies sibirica Ledeb). The wood materials were carbonized at various temperatures for 1 hour using experimental rotary kiln without any inert gas. The adsorption capacity of iodine and toluene, specific surface area and removal efficiency of acetic acid and ammonia gas of those charcoals were measured. The higher was the temperature for carbonization, the lower yields of charcoals were. Ash content of bark charcoal was higher than that of wood powder charcoal or fiber charcoal. Elemental analysis of woody charcoal revealed that the content of carbon was gradually lincreased as carbonization temperature was higher. When carbonization temperature was higher, adsorption capacity of woody charcoals for iodine was much improved. Wood powder charcoal and fiber charcoal were more effective for iodine adsorption rather than bark charcoal. Capacity of toluene adsorption was the highest in the charcoal of $600^{\circ}C$. Charcoals produced at high temperature efficiently removed acetic acid gas, while charcoals carbonized at low temperature such as $400^{\circ}C$ were proper to remove ammonia gas. This difference may be explained that the acidity of charcoals depends on the carbonization temperature: charcoals of low temperature indicate acidic property, while those of high temperature turned to alkaline.