• Journal of Powder Materials
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• v.22 no.3
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• pp.187-196
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• 2015

With the stabilization of Korea's industrialization, it has become interested in the efficient use of rare metals, climate change and industrial environment and safety etc. It is thus making efforts to implement economic policies that address such issues. Therefore it is necessary to understand the demand, supply and use of metal materials. Since 2010, the Korean government has developed the integrated material flow methodology and has been trying to examine the demand, supply and use of metal materials. In 2013, the Korean government surveyed the material flow of chromium. Material flow analysis and environment emission of chromium were investigated 8 steps; (1) raw material, (2) first process, (3) Intermediate product, (4) End product, (5) Use/accumulation, (6) Collection, (7) Recycling, (8) Disposal. Chromium was used for stainless steel, alloy steel, coated sheets, refractory material and coating materials. Recycling was done mainly in use of stainless steel scrap. To ensure efficient use of chromium, process improvement is required to reduce the scrap in the intermediate product stage. In the process of producing of the products using chromium, it was confirmed that chromium was exposed to the environment. It requires more attention and protection against environment emission of chromium.

• Nuclear Engineering and Technology
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• v.34 no.4
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• pp.396-405
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• 2002

An experimental study on counter-current flow limitation phenomena in narrow annular passages was carried out The gap sizes tested were 1, 2 and 3 mm. This is very small compared with the outer diameter of the annular passage, 500 mm. It was visually observed that a CCFL might occur in some part of the periphery while the other part is remained in a counter current flow pattern. That is, non-uniform behaviour of fluids due 4o a 2-dimensional effect appear in a large diameter facility. Because of this non-uniformity, a CCFL is defined in the present work as the situation where net water accumulation is sustained. That is, some amount of water should not be allowed to penetrate the gap and accumulate over the gap at CCFL criterion. The measured data are presented in the form of Wallis＇type correlation with characteristic length of gap size. It was found that the present correlation is in good agreement with other empirical correlation based on measurements whose test section diameter is close and the gap size is much larger than that of the present test section.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.973-979
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• 2010

The objective of this study was to determine the effect of electrical conductivity (EC) of nutrient solution on the growth, nutrient uptake of potted kalanchoe plants ($Kalanchoe$ $blossfeldiana$ 'New Alter') and the nutrient accumulation at the growing media with growth stage in ebb and flow subirrigation systems. Significant differences in leaf area, plant height, and dry weight of the plants were found among the different ECs of nutrient solution of 0.8, 1.6, 2.4, and $3.2dS{\cdot}m^{-1}$. Particularly the difference in plant growth became significantly greater from 5 weeks after treatment. The overall growth was the highest at EC $1.6dS{\cdot}m^{-1}$. Leaf area, plant height, and dry weight were maintained higher when EC increased to $2.4dS{\cdot}m^{-1}$, but rapidly decreased after EC $3.2dS{\cdot}m^{-1}$. The uptake of NO3-N was the greatest while that of $Mg^{2+}$ was the lowest at EC $1.6dS{\cdot}m^{-1}$, even though small differences were found among macro elements. The EC at the top layer of the growing media was 1 to 3 times higher than that at the bottom layer. Nutrient accumulation was accelerated in both the top and bottom layers with growth stage. At EC $3.2dS{\cdot}m^{-1}$, the growth of the plants was suppressed due to higher nutrient accumulation at the growing media. From the results, the strength and composition of nutrient solution should be determined by considering nutrient accumulation at the growing media in addition to EC of nutrient solution in ebb and flow subirrigation systems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.465-471
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• 2012

To compare the accumulation of paralytic shellfish poison (PSP) in different marine organisms, the occurrence and variation of PSP were surveyed in blue mussel Mytilus edulis, oyster Crassostrea gigas, short neck clam Ruditapes philippinarum, bay scallop Argopecten irradians, and warty sea squirt Styela clava collected from Jinhae Bay, Korea, in 2005 and 2006 year. We also investigated the ability of the blue mussel to detoxify PSP by relaying and depuration (via the water flow or water circulation system). In the marine organisms examined, PSP levels were the highest in blue mussel, followed in order by bay scallop, oyster, short neck clam, and warty sea squirt. Comparing the maximum PSP levels in the bivalve species examined in 2005 and 2006, PSP in blue mussel was 1.6-2.0, 4.0-5.9, and 5.1-6.0 times higher than in bay scallop, oyster, and short neck clam, respectively. Therefore, blue mussel could be useful as a bioindicator for PSP monitoring. With the increasing PSP levels in blue mussel in 2006, the proportion of PSP in its digestive gland increased to 95.1% when the maximum level was detected from the whole tissues of blue mussel on May 29. Subsequently, the PSP proportion in the digestive gland decreased as the PSP level in whole tissue decreased. The detoxification of PSP in blue mussel was greatest with relaying, followed by the water flow, and water circulation systems. Relaying decreased the PSP level below the regulatory limit of $80{\mu}g$/100 g after 2 days in low toxic sample with $124{\mu}g$/100 g, and after 7 days in high toxic sample with $401{\mu}g$/100 g. During depuration in the blue mussel with $401{\mu}g$/100 g via the water flow system, the PSP amounts in the digestive gland decreased by about 50% after 1 day, and about 77% after 7 days. In contrast, the PSP amounts in the soft body, gill, and mantle did not change significantly with depuration.

• Journal of Korea Water Resources Association
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• v.35 no.4 s.129
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• pp.345-358
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• 2002

The flow apportioning algorithms with digital elevation models have been developed to reflect reasonable flow divergence properties but they showed several defects related to the connectivity of channel cells, various divergence features along to local topography and channel cells' size etc. Topographic data used by existing flow apportioning algorithms are flow accumulation area and local slope. However, the size and location of channel cells which play the dominant role in the flow pathway were not properly considered. Therefore, a new flow apportioning algorithm considering various flow divergence characteristics in the complicate terrain is proposed. The GA optimization scheme is used to represent the location and scale of the channel pixel. Improved result can be obtained by using both a new flow apportioning algorithm and optimization.

• Animal Bioscience
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• v.35 no.5
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• pp.763-777
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• 2022

Objective: Excessive lipid accumulation in adipocytes results in prevalence of obesity and metabolic syndrome. Curcumin (CUR), a naturally phenolic active ingredient, has been shown to have lipid-lowering effects. However, its underlying mechanisms have remained largely unknown. Therefore, the study aims to determine the effect of CUR on cellular lipid accumulation in porcine subcutaneous preadipocytes (PSPA) and to clarify novel mechanisms. Methods: The PSPA were cultured and treated with or without CUR. Both cell counting Kit-8 and lactate dehydrogenase release assays were used to examine cytotoxicity. Intracellular lipid contents were measured by oil-red-o staining extraction and triglyceride quantification. Apoptosis was determined by flow cytometry and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling assay. Adipogenic and apoptosis genes were analyzed by quantitative polymerase chain reaction and Western blot. Results: The CUR dose-dependently reduced the proliferation and lipid accumulation of PSPA. Noncytotoxic doses of CUR (10 to 20 μM) significantly inhibited extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and expression of adipogenic genes peroxisome proliferation-activity receptor-γ (PPAR-γ), CCAAT/enhancer binding protein-α, sterol regulatory element-binding protein-1c, adipocyte protein-2, glucose transporter-4 as well as key lipogenic enzymes fatty acid synthase and acetyl-CoA carboxylase, while ERK1/2 activation significantly reversed CUR-reduced lipid accumulation by increasing PPAR-γ. Furthermore, compared with differentiation induced media treated cells, higher dose of CUR (30 μM) significantly decreased the expression of AKT and B-cell lymphoma-2 (BCL-2), while increased the expression of BCL-2-associated X (BAX) and the BAX/BCL-2 expression ratio, suggesting triggered apoptosis by inactivating AKT and increasing BAX/BCL-2 ratio and Caspase-3 expression. Moreover, AKT activation significantly rescued CUR inhibiting lipid accumulation via repressing apoptosis. Conclusion: These results demonstrate that CUR is capable of suppressing differentiation by inhibiting ERK1/2-PPAR-γ signaling pathway and triggering apoptosis via decreasing AKT and subsequently increasing BAX/BCL-2 ratio and Caspase-3, suggesting that CUR provides an important method for the reduction of porcine body fat, as well as the prevention and treatment of human obesity.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.5
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• pp.47-54
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• 1996

본 연구에서는 지표면유출과 중간유출의 수문학적과정을 함께 모의발생 시키는 합성 유역모델이 제시되었다. 본 모델은 디지털지형모델과 상호 연결되도록 하였으며 지형이 복잡한 지역에서도 유출이 시간과 공간적으로 누가계산되어 이 분야의 조사연구에 필요한 정보를 제공할 수 있다. 본모델을 이용 유역의 불투수층 위에 분포해있는 토양의 중간계층과 토양수분의 계산 및 침투/용탈의 과정을 모의 발생시킬 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1340-1345
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• 2001

In this paper, we proposed the method computing the optimal solution of Optical Flow(OF) representing the moving information of moving object and improving the operating speed. In order to do that, we computed the optimal solution of OF using the Combinatorial Hough Transform(CHT) and Voting accumulation and simply searched the moving object compared to conventional method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.291-293
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• 1997

The effect of strain accumulation on the superplastic deformation behavior has been investigated through a series of load relaxation tests. The experimental results were analyzed using the recently proposed inelastic constitutive theory. The superplastic deformation of fine grained materials is confirmed to consist of grain boundary sliding and accommodating grain matrix deformation. However the flow behavior is changed with the plastic strain. It is believed that the microstructural changes such as grain growth and cavitation affect the superplastic deformation behaviors.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.318-320
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• 2011

Numerical study was conducted to simulate the heat transfer on the real launch vehicle base. Three different base temperatures were chosen, to simulate the heat accumulation on the base. Moreover, six different pressure ratio conditions were used to express the different air conditions. As a result, the table that can used to estimate the base heat fox along the base temperature and pressure condition was made.