• Title/Summary/Keyword: accumulation

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Three-dimensional Numerical Simulation of Driftwood Accumulation and Behavior Around Bridge Piers (교각 주변 유목 집적 및 거동 특성 3차원 수치모의)

  • Park, Moonhyeong;Kim, Hyung Suk
    • Ecology and Resilient Infrastructure
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    • v.7 no.4
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    • pp.336-344
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    • 2020
  • The prediction and evaluation of driftwood accumulation around river-crossing structures are essential because driftwood accumulation increases during flood disasters. In this study, the driftwood accumulation and behavior around bridge piers were evaluated via a numerical model that could be employed to analyze three-dimensional turbulent flow and driftwood motion. The moving particle semi-implicit-based model for driftwood motion was sensitive to the number of spheres. The numerical results showed that the approach velocity and the ratio of driftwood length to pier width were the key factors influencing driftwood accumulation, whereas the driftwood density had only a minor influence. Overall, it is expected that this study will contribute to the development of improved risk evaluation indexes for assessing driftwood accumulation around river-crossing structures.

A Review on the Absence of Accumulation Point in the Governer, Conception, Thoroughfare, Belt Vessel of Extra Meridian (기경팔맥 중 독맥, 임맥, 충맥, 대맥에 극혈이 없는 이유에 대한 연구)

  • Lee, Bong Hyo;Park, Ji Ha;Kim, Hee Young;Kim, San Deul;Yang, Hyun Dong;Lee, Ho Jung;Choi, Jae Won;Lim, Sung Chul;Kim, Jae Su;Lee, Yun Kyu;Lee, Hyun Jong;Jung, Hyun Jung;Jung, Tae Young
    • Korean Journal of Acupuncture
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    • v.30 no.2
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    • pp.81-87
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    • 2013
  • Objectives : Accumulation point is a useful acupoint for acute pain diseases. Among the eight extra meridians, only four (Yin Heel, Yang Heel, Yin Link, Yang Link vessel) have accumulation point and the others (Governor, Conception, Thoroughfare, Belt Vessel) do not. However, there is no explanation why these four meridians do not have it. So, the authors researched the literature to look for the reasons. Methods : We investigated 10 books and 1 paper about the 'accumulation point of extra meridians' using several search engines and researched reason why the other 4 meridian do not have it. Results : All of the 16 accumulation points are located on the 4 limbs. The four limbs have more Yang energy than the trunk. The governor, conception, thoroughfare, and belt vessels do not flow in the limbs. It seems that there is no acupoint located on deep gap enough to be the accumulation point among the four vessels. When it comes to the functions of these vessels, they are little related with the acute pain that is the main target of the accumulation point. Conclusions : From the results of this study, it seems to be reasonable that the four vessels do not have accumulation point.

Verification on Debris Reduction Ability of the Sweeper by Real Scale Experiment (실규모 실험검증을 통한 스위퍼의 유송잡물 저감능력 검토)

  • Kim, Sung-Joong;Jung, Do-Joon;Kang, Joon-Gu;Yeo, Hong-Koo;Kim, Jong-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.34-44
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    • 2016
  • This study is an experimental study about a facility for preventing the accumulation of floating debris at a bridge by flooding at a small river. Generally, structures installed at a small river are damaged frequently by floating debris during typhoons or localized rainfall events. On the other hand, there is no method available for preventing such damage. The facilities used in other countries to prevent such damage by the accumulation of floating debris include debris fins, deflectors, and sweeper. Among these facilities, the present study was conducted with a sweeper to investigate the damage-reducing capability through a real-scale accumulation experiment. A sweeper was installed in front of a bridge to bypass floating debris by self-rotation so that the floating debris may not be accumulate at the bridge. A small bridge model was prepared in a real-scale for the real-scale experiment. The accumulation reducing capability was compared through an accumulation experiment before and after the sweeper installation depending on the length of the debris and flow conditions. The result showed that the accumulation rate increased with increasing length of the debris or decreasing flow rate. The installation of a sweeper decreased the debris accumulation rate by a minimum of 55% to a maximum of 88% compared to the case without an installed sweeper. The result of the present study showed that the installation of a sweeper at a small river having a high potential of generating floating debris may help secure the stability of a bridge in the case of floating debris accumulation.

Reduction of Fat Accumulation in Broiler Chickens by Sauropus Androgynus (Katuk) Leaf Meal Supplementation

  • Santoso, Urip;Sartini, Sartini
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.3
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    • pp.346-350
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    • 2001
  • The present study was designed to evaluate the usefulness of Sauropus. androgynus leaf (SAL) meal on reducing fat accumulation in broiler chickens. Eighty unsexed broiler chickens were allocated to four treatment groups with five replicates of four chickens each. SAL meal supplementation had no effect on body, leg, back, breast, wing, liver and heart weights, carcass protein, moisture and ash contents (p>0.05). Broilers fed diets supplemented with 30 g of SAL meal had lower feed intake with better feed conversion ratio (p<0.05) than did the control chickens. SAL supplementation at all levels significantly reduced fat accumulation in abdomen region, and liver (p<0.01), and in carcass (p<0.05). Higher SAL supplementation resulted in lower fat accumulation in the carcass ($r^{2}=0.94$; p<0.01), abdomen ($r^{2}=0.99$; p<0.01) and liver ($r^{2}=0.98$; p<0.01). The current study showed that a 30 g supplementation of SAL meal to the broiler diet was effective to improve feed conversion ratio without reducing body weight. SAL meal supplementation to the diet reduce fat accumulation in broiler chickens.

Study on the Correlation between Thermal Characteristics and Heat Accumulation in the Coal Pile (석탄의 열적 특성과 석탄 내부의 승온 특성과의 상관관계 연구)

  • Lee, Hyun-Dong;Kim, Jae-Kwan
    • Journal of the Korean Society of Combustion
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    • v.15 no.4
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    • pp.58-64
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    • 2010
  • Spontaneous ignition tests of five different coals with non-iso-thermal and iso-thermal test method based on the standard test procedure of NF T20-036 were carried. These five coals included the 2 low rank coals and 3 bituminous coals. Test results showed that the ignition temperatures of all coals at the iso-thermal conditions were higher than that of non-isothermal condition, and those of low rank SM and BR coal in both nonisothermal and isothermal conditions were lower than bituminous AN and CN coals. The chemical species of coals such as oxygen and hematite also plays an important role in enhancing the ignition rate that the ignition temperature of SM coal was lowered. The heat accumulation tendency of five coals inside outdoor stack pile was monitored with emphasis on the change in the temperature of the coal depth in stack pile. In case of low rank BR coal, its temperature inside coal stack pile due to the rate of high heat accumulation and oxidation was $59^{\circ}C$ compared to $51^{\circ}C$ for other SW bituminous coal. And the heat accumulation rate inside coal stack piles was increased with increased the Cp value which it was defined as the specific heat of coal at constant pressure, whereas other factors such as thermal diffusivity and conductivity of coal relatively had less effect on heat accumulation.

Accumulation of wind induced damage on bilinear SDOF systems

  • Hong, H.P.
    • Wind and Structures
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    • v.7 no.3
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    • pp.145-158
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    • 2004
  • The evaluation of the accumulation of permanent set for inelastic structures due to wind action is important in establishing a criterion to select a reduced design wind load and in incorporating the beneficial ductile behaviour in wind engineering. A parametric study of the accumulation of the permanent set as well as the ductility demand for bilinear single-degree-of-freedom (SDOF) systems is presented in the present study. The dynamic analysis of the inelastic SDOF system is carried out using the method of Newmark for artificially generated time history of wind speed. Simulation results indicate that the mean of the normalized damage rate is highly dependent on the natural frequency of vibration. This mean value is relatively insensitive to the damping ratio if the damping ratio is larger than 5%. The scatter associated with the accumulation of the permanent set is very significant. The consideration of the postyield stiffness can significantly reduce the accumulation of the permanent set if the ratio of the yield strength to the expected peak response is small. The results also show that the ductility demand due to the wind action over a period of one hour for flexible structures can be much less than that for rigid structures or structures with larger damping ratio if the SDOF systems are designed with a reduced peak response caused by the fluctuating wind.

Proline Accumulation in Vigna angularis Seedlings Under Salt Stress

  • Lee, Hee-Kyung;Hong, Jung-Hee
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.4 no.1
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    • pp.51-57
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    • 2000
  • Changes in the proline accumulation of ten-day-old seedlings of Vigna angularis in response to NaCl treatment were monitored. The proline content increased gradually both with an increase in the exposure time to salt stress and in a concentration-dependent manner. The increased proline accumulation was stronger in the shoots than in the roots. The salt stress by itself resulted in a significant inhibition of the chlorophyll content. Pre-treatment with proline before salinization lasting 48 h did not significantly affect the endogenous proline level in the roots, in contrast, a considerable increase of proline was observed in the shoots. The application of exogenous proline to the seedlings increased the endogenous proline content and improved the root and shoot growth under saline conditions. Detached leaves also exhibited an increased proline level in response to the applied NaCl, however, at a lower magnitude than in the intact seedlings. The proline alleviated the inhibitory effect of the NaCl in a concentration-dependent manner, thereby suggesting that salinity is a strong inducer of proline accumulation. In addition, abscisic acid eliminated the inhibitory effect of the salt salinity, thereby indicating a protective role on salinity stress and a regulatory role in proline synthesis. Accordingly, it would appear that proline may be involved in salt tolerance.

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Cadmium Accumulation and Elimination in the Tissues of the Manila Clam, Ruditapes philippinarum, after Sub-chronic Cadmium Exposure

  • Jang, Seok-Woo;Kim, Seong-Gil;Choi, Ok-In;Kim, Seong-Soo;Kang, Ju-Chan
    • Fisheries and Aquatic Sciences
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    • v.12 no.4
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    • pp.324-330
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    • 2009
  • Cadmium (Cd) accumulation and elimination were assessed in the tissues of the clam R. philippinarum at four experimental concentrations (control, 10, 20, 100, and $200\;{\mu}g/L$) over an exposure period of 2 weeks and an elimination period of 1 week. Cd accumulated in the digestive gland, gill, and residual clam tissues, and accumulation increased with time of exposure and concentration (100 and $200\;{\mu}g/L$). After 2 weeks of Cd exposure, the order of Cd accumulation in tissues was gill > digestive gland > residual tissues. An inverse relationship was observed between concentration factor (CF) and exposure level, but the CF showed an increase with exposure time. During the depuration period, Cd concentrations in the digestive gland, gill, and residual tissues decreased immediately on the cessation of exposure, except in individuals at the $200\;{\mu}g/L$ concentration. The Cd elimination rate from tissues decreased in the order of digestive gland > gill > residual tissues during the depuration period.

Inhibitory Effects of Lactobacillus plantarum Q180 on Lipid Accumulation in HepG2 Cells

  • Chu, Jaeryang;Joung, Hyunchae;Kim, Byung-Kook;Choi, In-Suk;Park, Tae-Sik
    • The Korean Journal of Food And Nutrition
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    • v.32 no.6
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    • pp.738-744
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    • 2019
  • Recently, the prevalence of hyperlipidemia has been increasing, and consequently, the need to identify safe and effective treatments to control this chronic disease has also increased. The beneficial effects of probiotics have been revealed by several studies over the past few years, including their effects on hypertriglyceridemia. However, the mechanisms of action of probiotics are still unclear. The anti-obesity effects of Lactobacillus plantarum Q180 on lipid accumulation have already been demonstrated using an in vitro HepG2 cell model, and therefore, we investigated its efficacy and mechanism of action. Lipid accumulation was induced in HepG2 cells by palmitic acid treatment and then the cells were incubated with L. plantarum Q180 lysate or supernatant to investigate changes in lipid accumulation and expression of lipid metabolism-related genes. The results showed that the L. plantarum Q180-treated group exhibited significantly lower levels of lipid accumulation and mRNA expression of lipid synthesis- and adipogenesis-related genes than the palmitic acid-treated group did. These results indicate that L. plantarum Q180 may contribute to alleviating hypertriglyceridemia by inhibiting lipid synthesis.