• Magazine of the Korea Concrete Institute
• /
• v.11 no.1
• /
• pp.89-97
• /
• 1999

In this study, fifteen reinforced high-strength lightweight concrete(HLC)beams were tested to investigate shear behavior of specimens according to shear reinforcement ratio. Test variables are shear span to effective depth ratio(a/d=2.5, 3.5, 4.5) and shear reinforcement ratio(0~1.0${\rho}_{v,ACI}$). Concrete compressive strength and tensile steel reinforcement ratio are constantly 439kg/$cm^2$ and 0.0203, respectively. Test results for the HLC beams showed that ACI code equation underestimates the shear strength of concrete($V_c$), and overestimates the shear strength of shear reinforcements($V_s$). It is revealed that the effectivenesses of shear reinforcements of reinforced HLC beams are lower than those of normal weight concrete beams. Then, the shear strengths of shear reinforcements are increased in proportion not to first degree of shear reinforcement ration but to square root of them.

• Membrane Journal
• /
• v.25 no.3
• /
• pp.268-275
• /
• 2015

Effects of aeration intensity on local fouling were investigated in submerged membrane modules. Higher liquid velocities were observed at the section with the lower fiber packing density. The liquid velocity is increased with increasing the gas-liquid injection factor. The high shear stress coincided with the high liquid velocity. The shear stress increases with the increasing of gas-liquid injection factor and the liquid velocity improves with the increasing of gas-liquid injection factor. Irreversible fouling resistance ($R_{ir}$) of the fiber position is significant in a local region of high suction pressure near the suction point of the fiber (position 1). The ratio of $R_{ir}/R_m$ and $R_{ir}/R_r$ of position 1 was highest compared to the position 2 and 3. Irreversible fouling resistances results confirmed the preferential deposition of foulants near the suction part of the fiber where the local suction pressure is the highest and correspondingly, more particles are accumulated to the membrane surface. The effects of local fouling along the fiber length are significant factors to optimize the design of submerged modules.

• Korean Journal of Food Science and Technology
• /
• v.22 no.3
• /
• pp.255-260
• /
• 1990

The effects of different concentrations of tocopherols on the oxidation stability of evening primrose oil (EPO) in the dark $(35{\pm}2^{\circ}C)$ were evaluated by some physicochemical characteristics such as peroxide, conjugated diene value and fatty acid composition. The results of the present study were as follows; Alpha-tocopherol at all concentrations (0.02%, 0.05%, 0.10%) showed a prooxidant effect during autoxidation of EPO. This prooxidant activity of alpha-tocopherol increased as its concentration increased rapidly. Delta-tocopherol showed antioxidant activity as its concentration increases at an early stage of storage. But the activity was fairly poor antioxidant activity and was not greater than antioxidant activity of BHT. However, the antioxidant effect of delta-tocopherol and BHT showed no apparent differences as compared with result of none.

• Food Science and Preservation
• /
• v.8 no.4
• /
• pp.393-398
• /
• 2001

Changes in physicochemical and microbiological properties of seafood bun containing kimchi were investgated during storage at 20$^{\circ}C$. pH of seafood bun tended to decrease and titratable acidity tended to increase during storage, as the kimrhi added more the pH was higher and titratable was lower. Acidity of seafood bun tended to increase during storage, the acidity was lower in seafood added kimchi than in control. Peroxide value of seafood bun added kimchi was lower than that of control, the value decreased with kimchi content. VBN and TBA values increased during storage, as the kimchi added more the value was lower. Viable colony and E. coli count significantly increased during 2 days of storage and tended to slightly increase afterward. The seafood bun added 20% kimchi obtained higher scores than other samples.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.32 no.2
• /
• pp.167-178
• /
• 2008

Despite the fact that chogakpos are part of our wonderful Kyubang(the women's quarters in the Chosun Dynasty) culture with their own unique beauty and artistic values, there has been no scientific and objective proof of their aesthetic values. Once they are proved for their beauty through scientific analysis, they will be recognized worldwide along with our unique culture. The methodology included a review of related literature and theses along with magazines, periodicals, and Internet books. The analysis of lines parting, the dimensions of chogakpos were carried out over 108 pieces introduced in Old Pojagis by Heo Dong-hwa. As for line parting, the dimensions of chogakpos were measured to see if the golden and Geumgang ratio could be applied and to discover their unique partition ratio. As a result, there was the presence of the golden ratio applied to them with the golden curves from golden triangles and rectangles also found therein. The Yeoijumunbo confirmed that there was the golden ratio between the radius of a circle and a side of a regular decagon inscribed in the circle. The common line ratio among the squares, isosceles triangles, wanes, and overlapping rectangles was around 1:1.31, which means that there was a unique line ratio in the traditional chogakpos. Furthermore, the ratio of 1:1.31 was close to the Geumgang ratio commonly used in the traditional buildings of Korea.

• Journal of IKEEE
• /
• v.23 no.2
• /
• pp.370-374
• /
• 2019

It was found that temperature and humidity did not affect the leakage current since the leakage current was irregularly increased or decreased at a temperature of $22^{\circ}C$ to $32^{\circ}C$ and a humidity of 60.0% to 96.0%. The insulation resistance in the vicinity of $26^{\circ}C$ was $10.70M{\Omega}$ to $4,000.00M{\Omega}$ and was low from $9.10M{\Omega}$ to $1,000.00M{\Omega}$ before and after $26^{\circ}C$. As the humidity was increase in a range of 60%~96%, the insulation resistance was reduced from $4,000.00M{\Omega}$ to $4.80M{\Omega}$, which indicates that the temperature and humidity had an influence on the insulation resistance. The leakage current and the insulation resistance of the branch circuit to the cooking facilities were compliant with less than 1.00 mA and more than $0.20M{\Omega}$. Leakage current of 1.89 mA was non-compliant but the insulation resistance was compliant with the value of $65.00M{\Omega}$.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.1C
• /
• pp.41-51
• /
• 2008

The load distribution and deformation of single piles which is embedded in Jumunjin sand and Kimhae clay are investigated, based on small scale model tests. Special attention is given to the consideration of flexural rigidity in laterally loaded piles. To consider the flexural rigidity of the pile, tests are performed with the aluminium piles of three different length under different relative densities and undrained shear strength. The test results indicate that the initial slope from the results of tests is proportional to the depth and pile-soil rigidity in both soils. But the increasing rate of the initial slope in the clay is less than in the sand. In addition, the soil resistance is more related to the depth and soil condition than the pile rigidity. Base on the test results, an empirical formula is proposed, which is good agreement with previously published small scale model test and field lateral load test.

• Korean Journal of Food Science and Technology
• /
• v.47 no.6
• /
• pp.738-743
• /
• 2015

This study was conducted to investigate the quality characteristics and antioxidant activities of jelly prepared with different amounts of aronia juice. Aronia juice was incorporated into jelly at concentrations of 3, 6, and 9%, based on the total weight of water. While the total water content of the jelly in different groups was not significantly different, the sugar content significantly increased with increasing levels of aronia juice. In the chromaticity measurements, $L^*$ and $b^*$ values decreased, whereas the $a^*$ values increased with increasing levels of aronia juice in the jelly. Further, the hardness and chewiness of jelly increased with increasing amounts of aronia juice. On the other hand, resilience, cohesiveness, and gumminess of the jelly were nearly similar for the control and samples treated with aronia juice. The total polyphenols, flavonoids, and anthocyanin contents increased proportionally with increasing levels of aronia juice. In addition, the antioxidant activity measured in terms of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activities of the jelly extracts were significantly higher for the samples containing aronia juice compared to the control and increased proportionally with increasing concentrations of aronia juice. In the sensory evaluation, the sample containing 6% aronia juice was perceived to have the best color, taste, texture, chewiness, flavor, and overall acceptance. These results suggest that aronia juice may be a useful ingredient in jelly for improving its quality as well as sensory and antioxidant potential.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.2
• /
• pp.177-184
• /
• 2017

The objective of this study was to determine the quality characteristics and antioxidant activities of Yaksik prepared with different amounts of turmeric powder. Turmeric powder was incorporated into Yaksik at different levels containing 1.7, 2.8, and 3.9% based on the total weight of ingredients. Moisture contents of Yaksik were 41.45~44.93% and increased with higher amount of turmeric powder. Ash and crude lipid contents did not show any significant differences between control and samples. The control group showed higher sweetness and lower pH than the other groups, and sweetness decreased and pH increased upon addition of turmeric powder. In the chromaticity determination, L value decreased while a and b values increased as turmeric powder increased. The total polyphenol and flavonoid contents proportionally increased with levels of turmeric powder. The antioxidant activities measured by DPPH and ABTS radical scavenging activities as well as reducing power were significantly higher than those of the control and proportionally increased as turmeric powder increased. In the sensory evaluation, control and Yaksik made with 1.7% addition of turmeric powder showed the highest preference in terms of color, taste, texture, and overall acceptance. These results suggest that turmeric powder may be a useful ingredient in Yaksik to improve quality and sensory properties.

• Journal of Korea Water Resources Association
• /
• v.46 no.2
• /
• pp.155-169
• /
• 2013

This study proposes proper forms of empirical formulas for the concentration time and storage coefficient based on their theoretical backgrounds and evaluates several existing empirical formulas by comparing them with the formula proposed in this study. Additionally, empirical formulas for the concentration time and storage coefficient of the Chungju Dam basin were derived using the forms proposed by considering their theoretical backgrounds, and compared with exiting empirical formulas. The results derived are summarized as follows. (1) The concentration time of a basin is proportional to the square of the main channel length, but inversely proportional to the channel slope, as the flood flow is generally turbulent. (2) The storage coefficient is proportional to the concentration time. (3) The comparison results with existing empirical formulas for the concentration time indicates that the empirical formulas like the Kirpich, Kraven (I), Kraven (II), California DoT, Kerby, SCS, and Morgali & Linsley are in line with the form proposed in this study. Among existing empirical formulas for the storage coefficient, the Clak, Russell, Sabol and Jung are found to be well matched to this study. (4) The application results to Chungju Dam basin indicates that among empirical formulas for the concentration time, the Jung, Yoon, Kraven (I), and Kraven (II) show relatively similar results to the observed in this study, but the Rziha shows abnormal results. Among the empirical formulas for the storage coefficient, the Yoon and Hong, Jung, Lee, and Yoon show somewhat reasonable results, but the Sabol shows abnormal results. In conclusion, the empirical formulas for the concentration time and storage coefficient developed in Korea are found to reflect the basin characteristics of Korea better.