• Ecology and Resilient Infrastructure
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• v.4 no.3
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• pp.180-185
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• 2017

Restoration of min-impacted arable land is often performed through stabilization of trace elements by amendment treatment combined with (clean) soil covering on the surface. Recently, soil loss problem from sloping remediated agricultural lands has risen as an emerging concern. In this study, efficacy of aggregation formation was assessed by single and binary treatments of four potential amendments (bentonite, lime, organic matter, and steel slag) applied on three cover soils having different clay contents (9.4, 14.7, and 21.2% for A, B, and C soils respectively). In results of single treatments, 5% organic matter for A soil and 5% lime for B and C soils were found most effective for the aggregation formation compared to the respective controls (without amendments). Among nine binary treatments, 3% organic matter + 1% lime for A soil and 1% organic matter + 3% lime for both B and C soils led to the highest formation of aggregation (30.4, 25.0, and 36.5% for A, B, and C soils). For a site-application, the soil erodibility difference between the cover soils (0.045, 0.051, and 0.054 for A, B, and C soils, respectively) and the national average of arable land (0.032) was assumed to be compensated by amendment addition, which is equivalent to 29.1% aggregation formation. To achieve the aggregation goal, 5% lime for A and B soils and 3% lime for C soil were best in the consideration of benefit/cost, thereby effectively and economically reducing soil loss from sloping remediation site. Soil alkalinity induced by lime treatment was not considered in this work.

• Nutrition Research and Practice
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• v.9 no.2
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• pp.137-143
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• 2015

BACKGROUND/OBJECTIVES: Mulberry leaves contain quercetin derivatives, which have the effects of reducing obesity and improving lipid and glucose metabolism in mice with obesity. It is not clear whether or not mulberry leaves can directly affect metabolic disorders, in the presence of obesity, because of the interaction between obesity and metabolic disorders. The aim of the current study was to assess the direct action of quercetin derivatives on metabolic disorders in non-obese conditions in short-term high-fat diet fed mice. MATERIALS/METHODS: C57BL/6N mice were fed a high-fat diet, supplemented with either 0% (control), 1%, or 3% mulberry leaf powder (Mul) or 1% catechin powder for five days. Anthropometric parameters and blood biochemistry were determined, and hepatic gene expression associated with lipid and glucose metabolism was analyzed. RESULTS: Body and white fat weights did not differ among the four groups. Plasma triglycerides, total cholesterol, and free fatty acids in the 1%, 3% Mul and catechin groups did not differ significantly from those of the controls, however, plasma glucose and 8-isoprostane levels were significantly reduced. Liver gene expression of gp91phox, a main component of NADPH oxidase, was significantly down-regulated, and PPAR-${\alpha}$, related to ${\beta}$-oxidation, was significantly up-regulated. FAS and GPAT, involved in lipid metabolism, were significantly down-regulated, and Ehhadh was significantly up-regulated. Glucose-metabolism related genes, L-PK and G6Pase, were significantly down-regulated, while GK was significantly up-regulated in the two Mul groups compared to the control group. CONCLUSIONS: Our results suggest that the Mul quercetin derivatives can directly improve lipid and glucose metabolism by reducing oxidative stress and enhancing ${\beta}$-oxidation. The 1% Mul and 1% catechin groups had similar levels of polyphenol compound intake ($0.4{\times}10^{-5}$ vs $0.4{\times}10^{-5}$ mole/5 days) and exhibited similar effects, but neither showed dose-dependent effects on lipid and glucose metabolism or oxidative stress.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.579-588
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• 2006

In recent years, the availability of high-strength reinforcing and prestressing steels leads us to build economically and efficiently designed concrete structural members. One of critical problems faced to the structural engineers dealing with these types of structural member is controls of crack width that is used as a criterion for the serviceability in the limit state design. Especially, flexural cracking must be controlled to secure the structural safety and to improve the durability as well as serviceability of the load carving members. The proposed method utilizes the results of pure tension test in which tensile loads are applied both side of specimen, done by Ikki. The bond characteristics of deformed reinforcing bar under pure tension is considered by the area of concrete and rib area. The results of proposed method are compared with the test data and the results show that the proposed method can take into account the dimensions, variation of sectional properties, and direction of reinforcing and gives more accurate maximum bond stress and corresponding relative slip than the existing methods. the characteristics of bonding is considered by using dimensionless slip magnitude and effective reinforcement ratio. The validity of the proposed equation is verified by test experimental data.

• Journal of the Korea Society of Computer and Information
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• v.24 no.12
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• pp.135-141
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• 2019

In this study, the "Insect Smart Farm Air Conditioning System" is designed and proposed for the control of breeding environment of Protaetia brevitarsis seulensis larvae. The proposed "Insect Smart Farm Air Conditioning System" separates the breeding room from the air conditioning room. It is a system that creates an environment optimized for breeding and distributes it into a breeding room. When controlling the environment through air-conditioning and humidifiers in insect farms, temperature and humidity vary from part of the breeding room to part. The solution to the problem can be suggested as a solution to the difficulty of producing white-spotted flower mounds of uniform size and weight when selling edible insects. By using the "Insect Smart Farm Air Conditioning System," the temperature difference can be reduced by 6℃ and the humidity difference by 24.7% compared to the environmental control of existing insect farms. The temperature and humidity of different parts of the breeding room were improved. Provide the optimal environment of Protaetia brevitarsis seulensis larvae at all times and ensure uniform CO₂ concentration. It can be expected to increase output through annual production and increase income for insect farmers. The proposed "Insecting Smart Farm Air Conditioning System" also controls the set temperature, humidity and CO₂. Environmental control of the breeding of other edible insects and the reproduction of mushrooms that require environmental control in breeding or breeding will also be possible.

• Geophysics and Geophysical Exploration
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• v.21 no.1
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• pp.15-25
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• 2018

Seismic inversion is a high-resolution tool to delineate the subsurface structures which may contain oil or gas. On the other hand, marine controlled-source electromagnetic (mCSEM) inversion can be a direct tool to indicate hydrocarbon. Thus, the joint inversion using both EM and seismic data together not only reduces the uncertainties but also takes advantage of both data simultaneously. In this paper, we have developed a simultaneous joint inversion approach for the direct estimation of reservoir petrophysical parameters, by linking electromagnetic and seismic data through rock physics model. A cross-gradient constraint is used to enhance the resolution of the inversion image and the maximum likelihood principle is applied to the relative weighting factor which controls the balance between two disparate data. By applying the developed algorithm to the synthetic model simulating the simplified gas field, we could confirm that the high-resolution images of petrophysical parameters can be obtained. However, from the other test using the synthetic model simulating an anticline reservoir, we noticed that the joint inversion produced different images depending on the model constraint used. Therefore, we modified the algorithm which has different model weighting matrix depending on the type of model parameters. Smoothness constraint and Marquardt-Levenberg constraint were applied to the water-saturation and porosity, respectively. When the improved algorithm is applied to the anticline model again, reliable porosity and water-saturation of reservoir were obtained. The inversion results indicate that the developed joint inversion algorithm can be contributed to the calculation of the accurate oil and gas reserves directly.

• Journal of the Korean Geotechnical Society
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• v.27 no.3
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• pp.85-94
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• 2011

Mixtures of sand and rubber particles ($D_{sand}/D_{rubber}=1$) are investigated to explore their characteristics under different stain level. Mixtures are prepared with different volumetric sand fractions ($sf=V_{sand}/V_{total}$). Experimental data are gathered from a resonant column, an instrumented oedometer, and a direct shear tests. Results show that sand and rubber differently control the behavior of the whole mixture with strain level. Non-linear degradation of small strain stiffness is observed for the mixtures with $sf{\geq}0.4$, while the mixtures with low sand fraction ($sf{\leq}0.2$) show significantly high elastic threshold strain. Vertical stress-deformation increases dramatically when the rubber particle works as a member of force chain. The strength of the mixtures increases as the content of rubber particle decreases, and contractive behavior is observed in the mixtures with $sf{\leq}0.8$. Rubber particle plays different roles with strain level in the mixture: it increases a coordination number and controls a plasticity of the mixture in small strain; it prevents a buckling of force chain in intermediate strain; it leads a contractive behavior in large strain.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.2
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• pp.35-46
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• 2008

Soil moisture is one of the important components in hydrological processes and also controls the subsurface flow mechanism at a hillslope scale. In this study, time series of soil moisture were measured at a hillslope located in Gwangneung National Arboretum, Korea using a multiplex Time Domain Reflectometry(TDR) system measuring soil moisture with bi-hour interval. The Box-Jenkins transfer function and noise model was used to estimate spatial distributions of soil moisture histories between May and September, 2007. Rainfall was used as an input parameter and soil moisture at 10 cm depth was used as an output parameter in the model. The modeling process consisted of a series of procedures(e.g., data pretreatment, model identification, parameter estimation, and diagnostic checking of selected models), and the relationship between soil moisture and rainfall was assessed. The results indicated that the patterns of soil moisture at different locations and slopes along the hillslope were similar with those of rainfall during the measurment period. However, the spatial distribution of soil moisture was not associated with the slope of the monitored location. This implies that the variability of the soil moisture was determined more by rainfall than by the slope of the site. Due to the influence of vegetation activity on soil moisture flow in spring, the soil moisture prediction in spring showed higher variability and complexity than that in early autumn did. This indicates that vegetation activity is an important factor explaining the patterns of soil moisture for an upland forested hillslope.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.311-318
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• 2014

PFOS (perfluorooctane sulfonate) is one of the perflourinated organic compound, which persist as a residual compound in the coastal environments. Intertidal mud crab Macrophthalmus japonicus mainly inhabits in coastal and bay ecosystems in Indo-Pacific region including Korea and reflects to environmental changes. In the present study, M. japonicus were exposed to different concentrations of PFOS and various ecotoxicological end-points such as survival rate, elimination of appendages, changes of the crust and internal organ color changes were investigated. Interestingly, the PFOS exposure showed concentration-dependent decrease of survival rate. High PFOS exposure ($30{\mu}gL^{-1}$) showed a low survival rate of 24% at 168 hours. Further, in comparison with the controls, the rate of elimination of appendages was also considerably increased in a time dependent manner upon PFOS exposure. Notably, with progression of time, an increased exposure to PFOS, test species showed whitening effect in a concentration-dependent manner, whereas the crab crust color was unchanged in the control. In addition, change in internal organs color and their visibility (clarity) observed in PFOS exposed crabs compared to control. Taken together, we suggest, eco-toxicology end-points of M. japonicus exposed to PFOS gave important biological information which could be useful to identify toxic contamination in the marine benthic environments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.28-34
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• 2020

A reservoir is defined as an artificial facility that stores and controls water during floods and droughts. Korea has constructed and managed reservoirs all over the country to benefit farming communities. The importance of reservoirs has decreased gradually due to urbanization and the spread of tap water, but the importance of water is increasing because of the recent shortage of water and the resulting rise in the price of water resources. Therefore, this study suggests countermeasures through an analysis of the used threshold for agricultural reservoirs. To this end, the forecast of rainfall up to 2100 was first analyzed using flood estimates and RCP scenarios through rainwater data collection. The increase in the RCP 8.5 scenario, the largest increase in the probability rainfall, was calculated by adding it to the current probability rainfall, and it was predicted that the marginal height of Odong Dam would reach its limit in 2028. Therefore, as a countermeasure against this, the measures to secure effective water storage were suggested through measures, such as lowering the height of Yeosu and installing movable beams. Overall, it is expected that effective management of the reservoirs used for agriculture will be possible in the future.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.42-50
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• 2019

As the industry develops in Korea, the use of hazardous chemicals is increasing rapidly and chemical accidents are increasing accordingly. Most of the chemical accidents are caused by leaks of hazardous chemicals, but there are also accidents in which all the substances are released instantaneously due to sudden high temperature/pressure or defection of the storage tanks. This is called catastrophic failure and its frequency is very low, but consequence is very huge when it occurs. In Korea, there were 15 casualties including three deaths due to catastrophic rupture of water tank in 2013, and 64 instances of failures from 1919 to 2004 worldwide. In case of catastrophic failure, it would be able to overflow outside the bund that reduces the evaporation rate and following consequence. This incident is called overtopping. Overseas, some researchers have been studying the amount of external overflow depending on bund conditions in the event of such an accident. Based on the previous research, this study identified overtopping fraction by condition of bund in accordance with Korea Chemicals Controls Act Using CFD simulation. As a result, as the height increases and the distance to the facility decreases while meeting the minimum standard of the bund capacity, the overtopping effect has decreased. In addition, by identifying the effects of overtopping according to atmospheric conditions, types of materials and shapes of bunds, this study proposes the design of the bund considering the effect of overtopping caused by catastrophic failure with different bund conditions.