• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.13-21
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• 2002

An extensive tension experiment was carried out to examine the variation of tensile strength in moist sand having moisture contents in the range of 0.5% < w < 4.0% with newly developed direct tension apparatus. It was observed that tensile strength of sand varied as functions of moisture content, relative density, presence of fines, and level of precompression. Tensile strength increases with increasing moisture content and fines, and this trend is more noticeable at increasing relative densities. However, the influences of relative density and fines on the tensile strength are substantially dependent on the water content. These effects are reduced at low moisture levels (w < 0.5%). The precompression effects also depend on the water content but less on the duration and level of the precompression.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.144-148
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• 2005

Kale leaf had similar contents of vitamin C, $NO_3$, p, Ca, Mg, and Fe with reported values. Among these internal quality factors, $NO_3$ content which has been a concern recently, ranged from 139 to 429 mg in 100 g fresh kale leaf, Kale showed high vitamin C content ranging from 106 to 203 mg in 100 g fresh leaf. The relative concentration of chlorophyll and b value color had a high correlation coefficient (r) with vitamin C, $NO_3$, Mg and Fe content. The relationship between $NO_3$ content and the relative concentration of chlorophyll was given by the following linear equation: $NO_3$ content : 21.55 + (5.907 ${\times}$ the relative concentration of chlorophyll) with an r of $0.910^{{\ast}{\ast}}$. Correlation between $NO_3$ content and b value was also very dependable (r = $-0.901^{{\ast}{\ast}}$). Vitamin C content and the relative concentration of chlorophyll showed a high correlation, r = $-0.858^{{\ast}{\ast}}$. Among internal quality factors, vitamin C content increased with decreasing $NO_3$ content and their correlation coefficient was high (r = $-0.795^{{\ast}{\ast}}$). Consequently, $NO_3$ content of kale leaf could be inferred from an external nondestructive method, such as the relative concentration of chlorophyll. We may be able to produce high quality kale leaves containing high amount of vitamin C and low content of $NO_3$ using this method.

• The Korean Journal of Food And Nutrition
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• v.11 no.2
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• pp.221-227
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• 1998

This study was investigate correlation of moisture content, relative humidity, pH, color difference, myoglobin(Myo), oxymyoglobin(Oxy) and metmyoglobin(Met). The moisture content, relative humidity of loin and shank were not changed uniformly during storage, the pH was raised according to storage period. The L value was raised at the closing stage of the storage period, the surface of the b value was higher than interior. Between Myo and Met were positive correlation in common with loin and shank. The surface and interior of loin were negative correlation between Oxy and Met, the surface and interior shank were positive correlation between Myo and L value and were negative correlation between Myo and Oxy. The moisture content, relative humidity, pH and color was not correlation uniformly.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.108-112
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• 1984

The sorption characteristics of red pepper powder stored at various relative humidity and temperature were studied. At low relative humidity below RH 57%, the sorption equilibrium was easily attained, whereas at higher relative humidity above RH 75%, the powder was browned by higher equilibrium moisture content. The moisture content of monolayer value for the powder was ranging from 11.32% to 12.13% with temperature. First order regression equation of equilibrium moisture content for relative humidity was determined.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1458-1465
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• 2010

A lot of dredging and reclaming projects are recently under way in Korea for the efficient use of limiting land space. Saemanguem area is special case of reclaiming by dredged soil. In case of a confined disposal of dredged soils by a pump dredger, generally coarse grained soils are separated from fines with dropping at the near part of the pump dredger. This kind of seperation of fine contents could be a factor of liquefaction by earthquake. In Korea, recently, earthquakes with magnitude of 3.0 or higher are distinctively increasing in 1990. In this study, cyclic shear characterics of Saemanguem Dredged sand depending on fine content were analyzed. A series of undrained cyclic triaxial test with cyclic stress ratio ($\sigma_d/{2\sigma_{{\upsilon}c}}'$) were performed on both isotropic consolidated specimen and sand with fine contents of 0%, 5%, 15%, 30%, 40% under the effective vertical stress of 100kPa and 50% and 60%, 70% of relative density for fine content of 0%, respectively. In the test results, cyclic shear strength increased by increasing of cyclic stress ratio($\sigma_d/{2\sigma_{{\upsilon}c}}'$) with increasing the relative density at the same number of cyclic under the effective confining pressure of 100kPa. It is almost highest the double amplitude(DA) 1%, 3%, 5%, 7.5% and 10% at fine content of 15% between Cyclic stress ratio($\sigma_d/{2\sigma_{{\upsilon}c}}'$) value at cyclic number five and fine content. Number of cyclic is 30 under the effective vertical stress of 100kPa, 70% of relative density for fine content of 15%. when the cyclic stress ratio at each relative density was compared at cyclic number five, the double amplitude(DA) 1%, 3%, 5%, 7.5% and 10%, and the pore-pressure ratio (${\Delta}u/{\sigma'}_c$) 0.95 value were compared; under the relative density of 70% and the effective confining pressure of 100kPa. The pore-pressure ratio (${\Delta}u/{\sigma'}_c$) 0.95 value showed a similar trend to the double amplitude (DA) 5% line.

• Carbon letters
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• v.10 no.1
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• pp.9-13
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• 2009

We propose an evaluation method of the relative content of single-walled carbon nanotubes (SWCNT) in SWCNT soot synthesized by arc discharge using UV-VIS-NIR absorption spectroscopy. In this method, we consider the absorbance of semiconducting and metallic SWCNTs together to calculate the relative content of SWCNTs with respect to a highly purified reference. Our method provides the more reliable and realistic evaluation of SWCNT content with respect to the whole carbonaceous content than the previously reported method.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.3
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• pp.33-40
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• 2020

Wood is one of the main materials of wooden building. Hanok also uses wood as its main component. Recently, Hanok continues to be built. Wood is affected by the climatic environment. The growth of decay bacteria is activated at more than 80% relative humidity. The microclimate environment and moisture content were measured for architectural cultural properties that have been maintained for a long time as a wooden building. The method analyzed the measured data by distinguishing between cloudy and sunny days. In the case of the old house, Anchae moisture content was higher than that of Sarangchae. This seems to be due to the narrow front yard or the planting of trees. The microclimate environment inside the house began to decrease in humidity from 8 am. According to the survey data, the relative humidity was less than 80% from 9 am when there was wind around 4-6 am. It appeared an hour earlier than in the absence of wind. As a result, the time interval for dehumidifying of wood was widened. Therefore, the wooden building is open to the front so there is airflow under the eaves during the daytime and wind in the morning appear to be alternatives in order to lower the moisture content.

• Journal of Plant Biology
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• v.33 no.2
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• pp.119-126
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• 1990

The content of canavanine was measured and analyzed in leaves, roots and xylem exudate of Canavalia lneata. In non-nodulated plants, the cotyledons were removed after a week of sowing and the plants were grown for 3 weeks. The quantity of canavanine measured by canavanine specific-PCAF colorimetric assay was 9-10 $\mu$mol/g fresh wt. in leaves, 5-6 $\mu$mol/g fresh wt. in roots, and 0.3-0.5 $\mu$mol/ml in xylem exudate. When free amino acids of leaves, roots, and xylem exudate were analysed by HPLC, the relative proportion of asparagine plus glycine was the highest and canavanine was high secondarily. And the relative proportion of canavanine among total free amino acids was 30-35% in leaves and roots, and 12-13% in xylem exudate. In non-nodulated plants grown for 8 weeks, the canavanine content of each part was similar to that of 3-week-old plants. By the formation of nodules, the canavanine content of leaves, roots, xylem exudate, and nodules decreased apparently. In xylem exduate, the nitrogenous compounds were also analyzed. The relative contents of NO3-, free amino acids, and ureides(allantoin and allantoic acid) were 60-80%, 20-30%, and 5%, respectively. From these results, it can be assumed that canavanine is synthesized in the root of plant and nodulation affects the canavanine content. It is obvious that canavanine is considered one of the reduced-N forms transported via xylem.

• Journal of Biosystems Engineering
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• v.30 no.2 s.109
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• pp.95-101
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• 2005

Adsorption and desorption experiments were carried out on rough rice and brown rice (Nampyung) at 5, 15, 25, 35, $45^{\circ}C$ for moisture contents between 8.7 and $25\%$ (db). The method employed was to measure the equilibrium relative humidity (ERH) of air in contact with the grain under static conditions, using an electronic hygrometer The effects of temperature and moisture contents were investigated, and the measured values were fitted to the modified Henderson, the modified Chung-Pfost, the modified Halsey and the modified Oswin model. The ERHs of rough rice and brown rice decreased with an decrease in moisture content and temperature, and the effects of temperature was no significant at moisture content of $25\%$ (db). Equilibrium moisture content (EMC) of brown rice was higher than rough rice at same temperature and relative humidity. Desorption EMC is higher than the adsorption, but there is no significant difference between desorption and adsorption EMC in moisture content near $25\%$ (db) at rough rice and near 9, 21 and $25\%$ (db) at brown rice. The modified Oswin model was the best in describing the adsorption EMC and the modified Chung-Pfost model was the best in describing the adsorption ERH of rough rice. The modified Oswin model was the best in describing the adsorption EMC/ERH of brown rice. The modified Chung-Pfost model was the best in describing the desorption EMC/ERH of rough rice and brown rice.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.947-952
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• 2001

The prediction model is proposed to estimate the variation of compressive strength of fly ash concrete with aging. After analyzing the experimental result with the model, the regression results are presented according to fly ash replacement content and water/cement ratio. Based on the regression results, the influence of fly ash replacement content and water/cement ratio on apparent activation energy was investigated. According to the analysis, the model provides a good estimate of compressive strength development of fly ash concrete with aging. As the fly ash replacement content increases, the limiting relative compressive strength and initial apparent activation energy become greater. The concrete with water/cement ratio smaller than 0.40 shows that the limiting relative compressive strength and apparent activation energy are nearly constant according to water/cement ratio. But, the concrete with water/cement ratio greater than 0.40 has the increasing limiting relative compressive strength and apparent activation energy with increasing water/cement ratio.