• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1760-1765
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• 2008

A total of 60 one-day-old Yellow-feather broiler chickens were allotted into treatment and control groups. The treatment group was fed with the diet supplemented with 3% conjugated linoleic acid (CLA) for 48 d, while control group was fed with the diet supplemented with 3% rapeseed oil. Chickens were slaughtered in each group at the age of 49 d, and the blood and the abdominal adipose tissue were sampled. Serum cLeptin and serum cAdiponectin were measured by ELISA. The total RNA was extracted from adipose tissue to measure the abundance of the chicken growth hormone receptor (cGHR), insulin-like growth factor 1 (cIGF-1), insulin-like growth factor I receptor (cIGF-IR), peroxisome proliferator-activated receptor gamma ($cPPAR{\gamma}$), cAdiponectin and cAdipoIR mRNA by RT-PCR using ${\beta}$-actin as an internal standard. Results showed that the CLA decreased the abdominal fat index by 20.93% (p<0.05). The level of serum cLeptin but not serum cAdiponectin was significantly increased by CLA treatment (p<0.05). CLA down-regulated the relative abundance of cGH-R mRNA and $cPPAR{\gamma}$ mRNA in abdominal adipose tissue by 24.74% (p<0.05) and 66.52% (p<0.01) respectively. However, no differences were found between CLA treatment group and control group (p>0.05) in the relative abundance of cIGF-1, cIGF-IR, cAdiponectin, and cAdipoIR mRNA in abdominal adipose tissue. The data suggested that CLA inhibited abdominal fat deposition in broiler chicken may be determined by decreasing the GHR available for GH, and by inhibiting the differentiation of preadipocytes via down-regulation of $PPAR{\gamma}$, but independent of IGF and (or) GH-IGF pathway or adiponectin action.

• Journal of Forest and Environmental Science
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• v.38 no.1
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• pp.64-73
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• 2022

Increasing carbon and PM_2.5 concentrations have been emerging as serious environmental issues worldwide. The purpose of this study was to quantify carbon and PM_2.5 reduction by urban parks in Gangneung, Korea. A total of 35 parks were sampled by applying a random sampling method to survey tree planting structures and the areal distribution of land cover types of urban parks. These survey data and the Green Evaluation Technique (GET) computer program were used to estimate carbon and PM_2.5 reduction by trees. Mean tree density and cover in the study parks were 3.5±0.2 tree/100 m² and 44.5±3.0%, respectively. Annual carbon uptake and PM_2.5 deposition per unit area by trees averaged 2.8±0.2 t/ha/yr and 30.2±2.8 kg/ha/yr. Gangneung's urban parks annually offset the carbon emissions by 3.4% and the PM_2.5 emissions by 3.5%. Thus, urban parks played a significant role in reducing atmospheric carbon and PM_2.5 concentrations. Total annual carbon uptake and PM_2.5 deposition of urban parks in Gangneung were about 1,338.2 t/yr and 14,433.2 kg/yr. This study is expected to contribute to raising awareness of the role and importance of urban parks regarding carbon and PM_2.5 reduction.

• Geomechanics and Engineering
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• v.33 no.1
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• pp.11-18
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• 2023

This study explores a new energy partitioning approach to determine the fracture toughness of 3-D printed pristine/recycled high density polyethylene (HDPE) blends employing the essential work of fracture (EWF) concept. The traditional EWF approach conducts a uniaxial tensile test with double-edge notched tensile (DENT) specimens and measures the total energy defined by the area under a load-displacement curve until failure. The approach assumes that the entire total energy contributes to the fracture process only. This assumption is generally true for extruded polymers that fracture occurs in a material body. In contrast to the traditional extrusion manufacturing process, the current 3-D printing technique employs fused deposition modeling (FDM) that produces layer-by-layer structured specimens. This type of specimen tends to include separation energy even after the complete failure of specimens when the fracture test is conducted. The separation is not relevant to the fracture process, and the raw experimental data are likely to possess random variation or noise during fracture testing. Therefore, the current EWF approach may not be suitable for the fracture characterization of 3-D printed specimens. This paper proposed a new energy partitioning approach to exclude the irrelevant energy of the specimens caused by their intrinsic structural issues. The approach determined the energy partitioning location based on experimental data and observations. Results prove that the new approach provided more consistent results with a higher coefficient of correlation.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1683-1685
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• 1999

ITO films on plastic substrate were prepared by DC magnetron sputtering method using powdery target and their properties were investigated as a function of the deposition conditions. As the sputtering power and total pressure were higher, the resistivity of ITO films increased. The optical transmittance deteriorated with increasing sputtering power and thickness. As the total pressure increased, however, the optical transmittance improved at visible region of light. From these results, we could deposited ITO films with $8{\times}10^{-3}{\Omega}-cm$ of resistivity and 80% of transmittance at optimal conditions.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.332-342
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• 2010

A model has been developed to investigate in-river sediment and phosphorus dynamics. This advective-dispersive model is coupled with hydrodynamics and sediment transport submodels to simulate suspended sediment, total dissolved phosphorus, total phosphorus, and particulate phosphorus concentrations under unsteady flow conditions. It emphasizes sediment and phosphorus dynamics in unsteady flow conditions, in which the study differs from many previous solute transport studies, conducted in relatively steady flow conditions. The diffusion wave approaximation was employed for unsteady flow simulations. The first-order adsorption and linear adsorption isotherm model was used on the basis of the three-layered riverbed submodel with riverbed sediment exchange and erosion/deposition processes. Various numerical methods were tested to select a method that had minimal numerical dispersion under unsteady flow conditions. The responses of the model to the change of model parameter values were tested as well.

• Journal of the Korean Ceramic Society
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• v.38 no.4
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• pp.388-392
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• 2001

저압 화학증착법으로 등방성 흑연 기판 위에 탄화규소 증착층을 제조하였다. 반응관 내부의 전체 반응압력(이하 반응압력)을 1.5torr-100torr로 변화시켜 증착층의 미세구조에 미치는 영향을 조사하였다. 120$0^{\circ}C$ 이하에서는 전체 반응압력 변화에 상관없이 일정하게 낮은 증착속도를 보였으며, 미세구조는 round-top 구조를 나타내었다. 125$0^{\circ}C$, 10torr를 기준으로 증착온도와 반응압력이 증가함에 따라 미세구조가 round-top 구조에서 angular, faceted 구조로 변하였으며, 이는 반응압력이 증가함에 따라 증착기구가 표면반응에서 물질전달로 전이하였기 때문이다.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.4
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• pp.240-246
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• 1992

During the period from December, 1990 to November, 1991, dustfall samples were collected by deposit jar at 28 sites in Seoul area and the amount of deposits of seven dissolved components$(SO_4^{2-}, NO_3^-, NH_4^+, Na^+, Ca^{2+}, Mg^{2+})$ were measured. The total amount of deposit was in order of Spring > Fall > Winter > Summer, and the amount of soluble components were high in the northeast region (Sanggae and Jangwe) and southwest region (Sangdo, Kuro, Siheung and Oryu). Total amount of major soluble components highly depended on regional air flow rather than emission source characteristic, and showed the regional trend-Residential > Iidustrial > Commercial > Rural, and the seasonal trend-Winter > Fall > Spring > Summer.

• Tribology and Lubricants
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• v.19 no.5
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• pp.251-258
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• 2003

New method and device for the on-line measurement of soot concentration in a diesel engine oil are proposed, where the measurement principle is based mainly on attenuated internal total reflection. The detector were evaluated in various ranges of contaminated oils by carbon black particles. It was found that the proposed detector could be well used to monitor the oil deterioration due to soot contamination. Operational range of the detector was found from 0 to 5 mass percentage of soot content. Test results with water and fuel dilution showed that these effects were not remarkable. However, adsorption of carbon black particles onto the measurement surface was considered to be a critical problem of the detector. Effects of particle deposition on the interface was experimentally evaluated with the oil temperature and flow turbulence and discussed throughout this work.

• Journal of Life Science
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• v.11 no.2
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• pp.153-158
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• 2001

To investigate the effects of soil acidification on growth of Impatiens balsamina L. plants were transplanted to acidified soils with H$_2$SO$_4$ solution. The concentrations of soluble Ca, Mg, K, Al and Mn in the acidified soils increased with increment of H$^{+}$ addition to the soil. In both species, the plant height and root length were inhibited by soil acidification, showing much severer inhibition in Impatiens balsamina L. than in Tagetes patula L., As the soil pH decreases, the growth of underground parts decreased greatly than that of above ground parts in both species. Total dry weight decreased with increased Al concentration as well as lowered soil pH in both plants. There was a strong positive correlation between relative total dry weight and molar (Ca+Mg+K) / Al ratio of the soil. The results suggest that molar(Ca+Mg+K)/ Al ratio of the soil may be useful indicator for assessing the critical load of acid deposition in herb species.s.

• Korean Journal of Optics and Photonics
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• v.9 no.5
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• pp.300-306
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• 1998

We have studied the optical effects in dielectric multilayer due to the interdiffusion formed during the deposition process. We suggest a numerical method to calculate the optical properties of periodical multilayer thin-films with gradient-index profiles. Using this method the spectral transmittance and reflectance were obtained for Fabry-Perot type filters, broad-band total reflectors and antireflection filters with interdiffusion layers. Interdiffusion reduced the spectral band width of high reflectance in total reflectors, and deteriorated the characteristics of multilayer AR-coatings leading to a large variation of reflectance if the number of the layers is large.