• Title/Summary/Keyword: a-and b-value

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Studies on the Development of Bearing Capacity Reinforcement for the Foundation of Soil (기초지반의 지지력보강공법에 관한 연구)

  • 유동환;최예환;유연택
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.1
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    • pp.38-49
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    • 1988
  • This paper presented as follows results of laboratory model tests with various shaped footings on soil bed reinforced with the strips on the base of behaviour of soil structure according to the loads and triaxial test results reinforced with geotextiles. Their parameters studied were the effects on the bearing capacity of a footing of the first layer of reinforcement, horizontal and vertical spacing of layers, number of layers, tensile strength of reinforcement and iclination load to the vertical 1.Depending on the strip arrangement, ultimate bearing capacity values could be more improved than urreinforced soil and the failure of soil was that the soil structure was transfered from the macrospace to microspase and its arrangement, from edge to edge to face to face. 2.The reinforcement was produced the reinforcing effects due to controlling the value of factor of one and permeable reinforcement was never a barrier of drainage condition. 3.Strength ratio was decreased as a linear shape according to increment of saturation degree of soil used even though at the lower strength ratio, the value of M-factor was rot influenced on the strength ratio but impermeable reinforcement decreased the strength of bearing capacity. 4.Ultimate bearing capacity under the plane-strain condition was appeared a little larger than triaxial or the other theoretical formulars and the circular footing more effective. 5.The maximum reinforcing effects were obtained at U I B=o.5, B / B=3 and N=3, when over that limit only acting as a anchor, and same strength of fabric appeared larger reinforcing effects compared to the thinner one. 6.As the LDR increased, more and more BCR occurred and there was appeared a block action below Z / B=O.5, but over the value, decrement of BCR was shown linear relation, and no effects above one. 7.The coefficient of the inclination was shown of minimum at the three layers of fabrics, but the value of H / B related to the ultimate load was decreased as increment of inclination degree, even though over the value of 4.5 there wasn't expected to the reinforcing effects As a consequence of the effects on load inclination, the degree of inclination of 15 per cent was decreased the bearing capacity of 70 per cent but irnproved the effects of 45 per cent through the insertion of geotextile.

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Antioxidation Activities of Bottled Mustard Leaf Kimchi during Fermentation (병포장 갓김치의 항산화 효과에 대한 연구)

  • Kim, Bog-Nam
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.6
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    • pp.950-957
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    • 2009
  • Mustard Leaf Kimchi (MLK) is a traditional fermented Korean vegetable food. This study was conducted to investigate the effects of part vacuum treatment on MLK packed in a glass bottle during fermentation. There have been a few previous studies that examined the chemical and microbial changes during MLK fermentation. However, the major object of this study was to investigate the antioxidative activities of vacuum treated MLK. In this study, the antioxidative activity of vacuum treated mustard leaf Kimchi (VM) and control mustard leaf Kimchi (CM) were examined. VM and CM were fermented at $5^{\circ}C$ for 8 weeks. A model system was designed to evaluate the antioxidative activity of crude chlorophylls and carotenoids (CCC) extracts from Mustard leaf Kimchi. The oxidative reaction of the linoleic acid mixture system at $30^{\circ}C$ in the dark was quantified determining the peroxide value and conjugated dienoic acid content. The effect of the CCC extracts on lipid peroxidation in a rat liver homogenate was examined. Formation of lipid peroxides was estimated by the TBA value, and the CCC extracts were found to inhibit the TBA value. Chlorophyll a and b, and carotenoids, Which are the major components in the CCC extracts of Kimchi were isolated on a DEAE-sepharose CL-6B and Sepharose CL-6B column and TLC. The effects of chlorophyll a and b, caroteins on linoleic acid autoxidation were measured by determining the peroxide value. In addition, their effects on free radical scavenging were investigated by DPPH. In this assay, chlorophyll a showed the greatest antioxidative activity followed by chlorophyll b, and carotenoids. MLK contains a sufficient content of chlorophyll a and b, and carotenoid which have strong antioxidative activities.

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THE GROWTH OF SOLUTIONS OF COMPLEX DIFFERENTIAL EQUATIONS WITH ENTIRE COEFFICIENT HAVING FINITE DEFICIENT VALUE

  • Zhang, Guowei
    • Bulletin of the Korean Mathematical Society
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    • v.58 no.6
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    • pp.1495-1506
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    • 2021
  • The growth of solutions of second order complex differential equations f" + A(z)f' + B(z)f = 0 with transcendental entire coefficients is considered. Assuming that A(z) has a finite deficient value and that B(z) has either Fabry gaps or a multiply connected Fatou component, it follows that all solutions are of infinite order of growth.

A study on the Plumbing system noise of closet bowl by water supply pressure (급수압에 따른 대변기 설비소음에 관한 연구)

  • Kim, Hang;Choi, Eun-Suk;Ko, Kwang-Pil;Gl, No-Gab;Lee, Tai-Gang;Kim, Sun-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.11-16
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    • 2006
  • It appraises that use an indoor noise standard, a NC value which is a noise appraisal, a dB(A) value, a N value in foreign country because it doesn't yet ready an appraisal standard in domestic. Also, It appraises that the supply and drainage noise which could change water supply pressure, $4kg/cm^2,\;3kg/cm^2,\;2kg/cm^2,\;1.5kg/cm^2,\;1kg/cm^2$, bring about a noise and inquires how does noise level indicates according to each instruments. In case of a water supply pressure standard, $3kg/cm^2$, a C-605is $3{\sim}5dB(A)$ lower than another instruments in directly overhead stories. It appears that all of them is similar to level in directly under level except c-407(2)Analyzed the NC value, c-605is the lowest level, NC-50, of a water supply pressure, $4.0kg/cm^2$, c-407 is the highest level, NC-55.(3) In case of N value, which is one of water supply methods in Japan, it is the lowest level, N-55, of a water supply pressure, $4.0kg/cm^2$ same as NC value and C-407is the highest level, N-60.(4) In case of water supply that is likely to noise level, It appears 6dB(A) level gap each instruments, and C-605 is the lowest level, 63.9dB(A).

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Clustering of Skin Colors on Korean Adult Males and Their Preference Colors (한국 성인 남성의 피부색 분류와 선호색에 대한 연구)

  • 김구자
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.11
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    • pp.1338-1349
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    • 2003
  • The color of apparels has the close interdependency on the skin colors of the wearers. This study was carried out to group the skin colors of Korean males into several similar skin colors and to analyze their preference colors. The skin colors were measured quantitatively and classified into several clusters that has similar hue, value and chroma with Munsell color system that is internationally used to communicate the colors. Sample size was 420 Korean males. With color spectrometer, JX-777, 4 points of the body were measured. All subjects had been shown with 40 color chips and answered their preference colors. Data were analysed by K-means Cluster analysis, Duncan test, Frequency and Chi square test using SPSS WIN 10 statistical package. Findings were as follows: 1. The skin colors of Korean males were mixed with skin colors of YR, R, and Y. 2. 420 subjects who have YR color were clustered in 3 kinds of skin color groups. 3. The average face color of total subjects was 4.81YR 5.91/4.97 in Munsell color system, 60.74 in L value, 13.71 in a value, 24.54 in b value. 136 observations out of 420 subjects were composed of Type 1: 4.50YR 6.35/4.87 and 192 observations were composed of Type 2: 4.62YR 5.86/5.12 and 92 observations were composed of Type 3: 5.67YR 5.37/4.79. 4. The average skin color of total 420 subjects was 6.26YR 6.07/4.41 and 62.33 in L value, 10.64 in a value, 23.48 in b value. The average skin color of Type 1 was 6.27YR 6.44/4.27 and of Type 2 was 6.15YR 5.91/4.49 and of Type 3 was 6.49YR 5.84/4.43 respectively. 5. 3 groups showed that the most preference color of sport$.$casual was 2.5Y 8/16 and 7.5PB 4/16 and the most preference color to their skins was 7.5PB 4/16 and 7.5YR 7/16.

Effect of Ecklonia cava Powder on Color and Texture of Sugar-Snap Cookies

  • Park, Myeong Ju;Lee, Jun Ho
    • Food Engineering Progress
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    • v.15 no.1
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    • pp.85-89
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    • 2011
  • Freeze-dried Ecklonia cava powder was incorporated into cookie dough at 5 levels (0%, 1.5%, 3%, 4.5%, and 6%, w/w) by replacing equivalent amount of wheat flour of the cookie dough. After aging and sheeting, cookies were baked at $185^{\circ}C$ for 14 min in a convection oven. The baked cookies were cooled to room temperature for 30 min and packed in airtight bags prior to all measurements. Lightness $(L^*)$ decreased significantly as the E. cava powder content increased (p<0.05) and a decreasing trend in both redness ($a^*$-value) and yellowness ($b^*$-value) was observed. On the other hand, firmness increased significantly with an increase in E. cava powder content (p<0.05). Increases in E. cava powder concentration up to 6% in the cookie formulation significantly increased the intensities of all sensory attributes such as color, flavor, taste, and firmness (p<0.05). Correlation analysis indicated that the E. cava concentration correlated significantly with most of the properties except for $a^*$-value (p<0.01, 0.05, or 0.001). Properties such as firmness and sensory color and firmness correlated positively while $L^*$- and $b^*$-value correlated negatively with E. cava concentration. Sensory color correlated negatively with $L^*$- and $b^*$-value. Sensory firmness correlated positively with mechanically measured firmness.

Errors in One-Dimensional Heat Transfer Analysis in a Hollow Cylinder Feedwater Pipe (속이 빈 원관에서 1차원적인 열전달 해석의 오차)

  • Gang, Hyeong-Seok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.2
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    • pp.689-696
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    • 1996
  • A comparison is made of the heat loss from a hollow cylinder, computed using an one-dimensional analytic method and a two-dimensional separation of variables scheme. For a two-dimensional analysis, the temperature of the inner surface as a boundary condition can be varied along the length of the cylinder by varing the temperature variation factor, b. Comparisons of the heat loss from the hollow cylinder using these two methods are given as a function of non-dimensional cylinder length, the ratio of the outer radius to the inner radius, temperature variation factor and Biot number. The result shows that the value of the heat loss from the hollow cylinder obtained using the one-dimensional analytic method becomes close to the value given by the two-dimensional separation of variables scheme as the value of Biot number and the non-dimensional hollow cylinder length increase and as the ratio of the outer radius to the inner radius decreases.

The Effects of Void Ratio on Extrudability and Buildability of Cement-based Composites Produced by 3D Printers (3D 프린터용 시멘트 복합체의 간극비가 출력성과 적층성에 미치는 영향)

  • Seo, Ji-Seok;Lee, Bong-Chun;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.7
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    • pp.104-112
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    • 2019
  • The material properties of the 3D printing cement composite mortar were evaluated, and the performance range in which printing was possible was calculated using the void ratio in a fresh state as a single index. As a results of the tests, as the water-binder ratio (W/B) increased, the mortar flow value increased and the density and strength decreased. As the sand-binder ratio (SS/B) increased, the mortar flow value decreased. However, strength and density increased and decreased up to a certain SS/B. As admixture-binder ratio (Ad/B) increased, mortar flow value, density, and strength decreased. These trends make it difficult to mix-design to meet the target performances of 3D printing mortars, represented by extrudability and buildability. The value of mortar flow increased proportionally with the void ratio, while the density and strength apparently decreased as the void ratio increased. This indicates that void ratio can be utilized as a single index for controlling the material properties in the design of mortar mixtures. It was found that mortar mixture could be printed by a 3D printer when the void ratio was in the range from 0.6 to 0.7. This was verified by printing a mortar which has the void ratio of 0.634. The mortar was produced with the mixture design of W/B 35.0%, SS/B 60.0%, and Ad/B 0.1%. Further research applying diverse admixtures is needed to improve the quality of 3D printing output mortars.

Potent Inhibition of Monoamine Oxidase B by a Piloquinone from Marine-Derived Streptomyces sp. CNQ-027

  • Lee, Hyun Woo;Choi, Hansol;Nam, Sang-Jip;Fenical, William;Kim, Hoon
    • Journal of Microbiology and Biotechnology
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    • v.27 no.4
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    • pp.785-790
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    • 2017
  • Two piloquinone derivatives isolated from Streptomyces sp. CNQ-027 were tested for the inhibitory activities of two isoforms of monoamine oxidase (MAO), which catalyzes monoamine neurotransmitters. The piloquinone 4,7-dihydroxy-3-methyl-2-(4-methyl-1-oxopentyl)-6H-dibenzo[b,d]pyran-6-one (1) was found to be a highly potent inhibitor of human MAO-B, with an $IC_{50}$ value of $1.21{\mu}M$; in addition, it was found to be highly effective against MAO-A, with an $IC_{50}$ value of $6.47{\mu}M$. Compound 1 was selective, but not extremely so, for MAO-B compared with MAO-A, with a selectivity index value of 5.35. Compound 1,8-dihydroxy-2-methyl-3-(4-methyl-1-oxopentyl)-9,10-phenanthrenedione (2) was moderately effective for the inhibition of MAO-B ($IC_{50}=14.50{\mu}M$) but not for MAO-A ($IC_{50}$ > $80{\mu}M$). There was no time-dependency in inhibition of MAO-A or -B by compound 1, and the MAO-A and -B activities were almost completely recovered in the dilution experiments with an excess amount of compound 1. Compound 1 showed competitive inhibition for MAO-A and -B, with $K_i$ values of 0.573 and $0.248{\mu}M$, respectively. These results suggest that piloquinones from a microbial source could be potent reversible MAO inhibitors and may be useful lead compounds for developing MAO enzyme inhibitors to treat related disorders, such as depression, Parkinson's disease, and Alzheimer's disease.