• 한국포장학회지
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• 제24권3호
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• pp.107-112
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• 2018

납, 카드뮴 및 비소의 폴리카보네이트 기구류에서 식품으로의 이행 수준을 ICP-MS로 조사하였다. 분석법을 확립 및 검증(검량선, 검출한계, 정량한계, 회수율, 정밀성 및 측정불확도)하고 식품모사용매(4% 초산)로 용출시켜 이행량을 분석하였다. 폴리카보네이트 재질 기구인 컵 63종, 용기 62종, 물병 55종, 스푼 9종, 국자 6종 및 집게 5종으로 총 200종의 시료를 $70^{\circ}C$와 $100^{\circ}C$에서 30분간 용출한 결과, 납, 카드뮴 및 비소가 각각 $ND{\sim}4.67{\mu}g/L$, $ND{\sim}0.49{\mu}g/L$및 $ND{\sim}2.91{\mu}g/L$수준으로 용출되었다. 또한, 온도에 따른 이행량 차이를 관찰한 결과, $70^{\circ}C$보다는 $100^{\circ}C$에서 용출되는 이행량이 다소 높았다. 결론적으로 현재 국내에 유통 중인 폴리카보네이트 기구류 중 납, 카드뮴 및 비소는 식품용 기구 및 용기 포장 공전에 명시된 용출규격 이하로서 안전하게 관리되고 있는 것으로 판단되었다.

• 대한지하수환경학회지
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• 제3권2호
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• pp.51-59
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• 1996

지하 LPG 저장시설과 같은 지하수에 의존하는 시설물 인접지역에 폐기물매립장이 설치될 경우, 침출수 누출로 인한 지하수오염 예측 및 오염방지 대책수립이 요구되고, 이를 위한 지하수유동 및 용질 이동(Mass Transport) 해석을 실시하게 된다. 본 연구에서는 현재 U 지역 석유화학공단내에서 발생된 상기 와 같은 내용의 문제점을 해결하기 위하여 해석학적 해석 및 수치해석에 의한 침출수이동 예측을 실시하였으며 침출수제어 공법을 검토하였다. 해석학적 해석은 입력요소를 이송(Advenction)요인과 분산 (Dispersion)요인으로 구분하여, Peclet 수로 부터 각 요인의 침출수이동에 미치는 영향을 분석 검토하였으며, 보존성용질 이송확산 방정식으로부터 입력요소 변화율과 침출수이동속도 변화율의 관계를 함수식으로 도출하여, 입력요소 변화에 따른 침출수 이동속도 변화를 간단히 예측할 수 있었다. 수치해석은 지하수유동 및 용질이동 해석용 FEM 프로그램인 AQUA2D를 이용하여 침출수이동 예측을 위한 수치모의를 실시하였다. 침출수제어공법 검토를 위해서 3D 불연속체모형을 모의하고 모의된 모형을 대상으로 지하수유동해석을 실시하여 암반내 열극(Fracture)의 상호 연결성 분석을 통한 수벽(Water Curtain) 시스템의 타당성을 분석하였다. 해석학적 해석 및 수치모의 결과, 폐기물매립장으로 부터 지하 LPG 저장기지로 침출수가 30년 이내로 유입되는 것으로 예측되었으며, 이를 방지하기 위한 침출수 제어공법으로는 수직수벽 시스템이 효율적인 것으로 예측되었다.

• Clinical and Experimental Pediatrics
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• 제48권6호
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• pp.580-587
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• 2005

New evidence is emerging that airway smooth muscle(ASM) may act as an immunomodulatory cell by providing pro-inflammatory cytokines and chemokines, polypeptide growth factors, extracellular matrix proteins, cell adhesion receptors and co-stimulatory molecules. ASM can promote the formation of the interstitial extracellular matrix, and potentially contribute to the alterations within the extracellular matrix in asthma. In addition, extracellular matrix components can alter the proliferative, survival, and cytoskeletal synthetic function of ASM cells through integrin-directed signaling. Increased ASM mass is one of the most important features of the airway wall remodeling process in asthma. Three different mechanisms may contribute to the increased ASM mass : cell proliferation, increased migration and decreased rate of apoptosis. The major signaling pathways of cell proliferation activated by ASM mitogens are those dependent on extracellular signal-regulated kinase and phosphoinositide 3'-kinase. The key signaling mechanisms of cell migration have been identified as the p38 mitogen-activated protein kinase and the p21-activated kinase 1 pathways. ASM cells contain ${\beta}2$-adrenergic receptors and glucocorticoid receptors. They may represent a key target for ${\beta}2$-adrenergic receptor agonist/corticosteroid interactions which have antiproliferative activity against a broad spectrum of mitogens.

• 한국주거학회논문집
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• 제18권4호
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• pp.79-88
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• 2007

The purpose of the this study was to provide the basic information about the formation background of urban squatter and their housing state in Korea. This study was progressed on the basis of socio-historical point of view from after the Korean War to the present time. Therefore, this study considered the meaning of housing for urban squatter in the Korean housing history. For this study, the formation background of urban squatter was divided into five periods. The first one was the period of the policy on the mass migration (1955-1960) after the Korean War. The second period was the period of reproduction of deteriorated residential area (1960-1970) for the continuing mass migration policy. The third was the period of disbanding of deteriorated residential area (1970-1980) for redevelopment. The forth period was before the IMF (1980-1997) broke up the deteriorated residential area. The fifth period was after the IMF (1997-) produced the new poverty due to the unemployment and the business failure. Thus, such social change increased the number of urban squatter and created the new type urban poor.

• 방사성폐기물학회지
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• 제21권4호
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• pp.465-479
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• 2023

To ensure the safety of disposal facilities for radioactive waste, it is essential to quantitatively evaluate the performance of the waste disposal facilities by using safety assessment models. This paper addresses the development of the safety assessment model for the underground silo of Wolseong Low-and Immediate-Level Waste (LILW) disposal facility in Korea. As the simulated result, the nuclides diffused from the waste were kept inside the silo without the leakage of those while the integrity of the concrete is maintained. After the degradation of concrete, radionuclides migrate in the same direction as the groundwater flow by mainly advection mechanism. The release of radionuclides has a positive linear relationship with a half-life in the range of medium half-life. Additionally, the solidified waste form delays and reduces the migration of radionuclides through the interaction between the nuclides and the solidified medium. Herein, the phenomenon of this delay was implemented with the mass transfer coefficient of the flux node at numerical modeling. The solidification effects, which are delaying and reducing the leakage of nuclides, were maintained the integrity of the nuclides. This effect was decreased by increasing the half-life and the mass transfer coefficient of radionuclides.

• Advances in nano research
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• 제6권3호
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• pp.243-255
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• 2018

Polystyrene granules were combined with nanosilver to form a nanocomposite film. One-side migration was conducted to test into three food simulants (3% acetic acid, 10% ethanol and 95% ethanol) at $40^{\circ}C$ temperature on different period of time (2, 4, 6, 8 and 10 days). It was found that, among the simulants, the highest migration amount was obtained with 3% acetic acid, while the 95% ethanol revealed the least migration level. Diffusion coefficients of nanosilver particles into simulants were estimated by inverse simulation using experimental data of concentration variation in the simulants. The finite element method used to solve the mass transfer equation and the numerical results indicates the sameresponse with the experimental data. The numerical results confirmed that the highest diffusion coefficient for acetic acid 3% (1.82E-10 to $1.76E-9m^2\;s^{-1}$) and the lowest diffusion coefficient for ethanol 95% from 2 to 10 days were obtained, respectively. Also, results of diffusion coefficient - concentration relation showed, the diffusion coefficient had in direct correlation with time and concentration. The results indicated that, in the 3% acetic acid, due to the increasing of diffusion coefficient of silver nanoparticles, they are released faster and distributed uniformly.

• 한국지반신소재학회논문집
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• 제5권4호
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• pp.49-58
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• 2006

근래에 들어, 복합 라이너 시스템에서 점토차수재를 대신하여 GCL(Geosynthetic clay liner)의 사용이 급증하고 있다. 그러나, 과연 GCL의 수리학적 특성이 점토차수재와 대등하게 매립장 설계규준을 만족 시키는가의 여부는 오래동안 논란이 되어왔다. 실내시험 및 현장조사 결과 여러 가지 원인에 의해 GCL에 응력집중이나 비등방 분포 하중이 생길 때 국부적인 벤토나이트 유실로 팽윤된 GCL의 두께가 감소할 수 있음을 보여준다. 이 논문에서는 현장조사를 통하여 실내시험에서 얻어진 벤토나이트 유실을 확인하고 감소된 GCL 두께에 대한 수리학적 특성을 분석했다.

• Mass Spectrometry Letters
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• 제6권2호
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• pp.31-37
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• 2015

Phosphorylation upon protein is well known to a key regulator that implicates in modulating many cellular processes like growth, migration, and differentiation. Up to date, grafting of multidimensional separation techniques onto advanced mass spectrometry (MS) has emerged as a promising tool for figuring out the biological functions of phosphorylation in a cell. However, advanced MS-based phosphoproteomics is still challenging, due to its intrinsic issues, i.e., low stoichiometry, less susceptibility in positive ion mode, and low abundance in biological sample. To overcome these bottlenecks, diverse techniques (e.g., SCX, HILIC, ERLIC, IMAC, TiO₂, etc.) are continuously developed for on-/off-line enrichment of phosphorylated protein (or peptide) from biological samples, thereby helping qualitative/quantitative determination of phosphorylated protein and its phosphorylated sites. In this review, we introduce to the overall views of enrichment tools that are universally used to selectively isolate targeted phosphorylated protein (or peptide) from ordinary ones before MS-based phospoproteomic analysis.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.183-191
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• 2008

To determine the age structure of a Hynobius leechii breeding population and analyze relationships between the order of entrance to breeding ponds and physical parameters and age, we studied a wild population of the species in the Research Forests of Kangwon National University in Chuncheon, Kangwon, South Korea from March 16 to April 13, 2005. The age of breeding males ranged one to nine years old and that of females ranged from three to nine years old. The asymptotic sizes of males and females were 6.36 and 6.51 cm, respectively, and the growth coefficients of males and females were 0.71 and 0.81, respectively. The snout-vent length (SVL), head length, and body mass of males were all positively correlated with their age, but female age did not show a significant relationship with any physical parameter. The tail depth, body mass, and condition factors (SVL/body mass $\times$ 100) of both males and females were negatively related with the order of entrance to the breeding pond. The head width and SVL of males were also negatively correlated with the order of entrance, but the SVL of females was positively related with the order of entrance. These results suggest that physical parameters are more important determinants of breeding migration patterns than age. We discuss which of two hypotheses, the mate opportunity hypothesis and the susceptibility hypothesis, is better able to explain the order of entrance to breeding ponds for male and female H. leechii.

• 한국패류학회지
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• 제32권4호
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• pp.241-247
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• 2016

Macrophage Migration Inhibitory Factor (MIF) are well-defined role as unique cytokine and critical mediator in acute and chronic inflammatory diseases, autoimmune diseases. In this study, we isolated and characterized a full-length of MIF cDNA from the abalone (Haliotis discus hannai). The full-length cDNA of abMIF was of 1264 bp, consisting of a 5'-terminal UTR of 143 bp, an open reading frame of 360 bp and a 3-terminal UTR of 761 bp. The abalone MIF cDNA encodes a 119-amino acid polypeptide with a calculated molecular mass of 13.4 kDa and isoelectric point of 9.07. Multiple alignments and phylogenetic analysis with the deduced abalone MIF protein and showed strong homology with disk abalone (Haliotis discusdiscus). The deduced amino acid sequence of abMIF exhibited homology with other reported MIFs, such as 80%, with that of other disk abalone H. discus discus MIF gene. Quantitative real-time PCR (qRT-PCR) analysis indicated that abMIF was highly expression observed in hapatopacreas, intestine, foot, and gonad of normal conditioned abalone. Even though AbMIF mRNA level in hemocytes was low under the normal condition, it was sharply up-regulated and reached the maximum at 6 h post-infection with Vibrio parahaemolyticus, and then decreased at 24 h post-infection. This result indicates that abMIF plays an important role in responding in the innate immune system.