• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.4
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• pp.172-183
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• 2009

For the effects of the nonlinear temperature profiles and reduced-gravity conditions we conduct a two-dimensional numerical modeling and simulations on the physical vapor transport processes of $Hg_2Cl_2-Xe$ system in the horizontal orientation position. Our results reveal that: (1) A decrease in aspect ratio from 5 to 2 leads to an increasingly nonuniform interfacial distribution and enhances the growth rate by one-order magnitude for normal gravity and linear wall temperature conditions. (2) Increasing the molecular weight of component B, Xenon results in a reduction in the effect of solutal convection. (3) The effect of aspect ratio affects the interfacial growth rates significantly under normal gravity condition rather than under reduced gravitational environments. (4) The transition from the convection-dominated regime to the diffusion-dominated regime ranges arises near at 0.1g$_0$ for operation conditions under consideration in this study.

• Journal of Magnetics
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• v.11 no.4
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• pp.182-188
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• 2006

The search for high-density recording materials has been one of most active and vigorous field in the field of magnetism. $FePt-L1_{0}$ nanoparticle has emerged as a potential candidate because of its high anisotropy. In this paper, we provide an overview of recent work at Argonne National Laboratory that contributes to the ongoing dialogue concerning the relation between structure and properties of the FePt nanoparticle system. In particular we discuss the ability to control structure and properties via dosing with Cr. Cr-dosed FePt films were grown via molecular beam epitaxy and annealed at $550^{\circ}C$ in an ultrahigh vacuum chamber, and were studied with the surface magneto-optic Kerr effect (SMOKE), scanning electron microscopy (SEM) and x-ray magnetic circular dichroism (XMCD). We found that small dosage of Cr helps to generate $L1_{0}$ phase FePt magnetic nanoparticles with small size, defined shape and regular spatial distribution on MgO (001) substrate. The nanostructures are ferromagnetic with high magnetic coercivity (${\sim}0.9T$) and magnetic easy axis in the desired out-of-plane orientation. We also show that controlling the lateral region where nanostructures exist is possible via artificial patterning with Cr.

• The Korean Journal of Rheology
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• v.8 no.2
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• pp.103-118
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• 1996

변형된 Maxwell 모델을 모의 데이터와 폴리스티렌의 동적 실험 데이터인 G＇과 G ＂에 적용하여 연속 완화시간 스펙트럼을 결정하였고, Maxwell 모델을 사용했을 때 얻어지 는 불연속 완화시간 스펙트럼과 비교하였다. MGMM과 GMM 모두 선형회귀 방법과 비선 형회귀 방법을 사용하여 완화시간 스펙트럼을 결정하였는데 비선형 방법을 사용했을 때 선 형방법에 비해 좀 더 만족스러운 결과를 얻을수 있었다. 모의 데이터의 경우 사용한 완화시 간의 수가 많은 경우에는 MGMM과 GMM 모두 원래의 스펙트럼을 잘 재현했으나 완화시 간의 수가 작은 경우에는 MGMM이 GMM에 비해 원래의 완화시간 스펙트럼을 보다 잘 나 타내었다. 또 단분산성폴리스티렌의 경우 MGMM과 GMM의 완화시간 스펙트럼이 모두 작 은 완화시간 영역에서는 분자량에 무관했고 큰 완화시간 영역에서는 분자량이 커질수록 스 펙트럼이 완화시간이 커지는 쪽으로 이동하였다. 또 두드러진 terminal 완화시간을 볼수 있 었다. 그러나 다분산성 폴리스티렌의 경우에는 단분산성의 경우와는 달리 두드러진 terminal 완화시간을 볼수 없었다. 그리고 MGMM의 파라미터 m은 분자량 분포에 크게 의존함을 알 수 있었으며 연속 완화시간 스펙트럼에서 계산된 불연속 완화시간 스펙트럼이 GMM에서 얻어진 불연속 완화시간 스펙트럼과 잘 일치함을 볼수 있었다.

• Journal of Environmental Science International
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• v.21 no.11
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• pp.1361-1369
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• 2012

A biological assessments of fish community structure were carried out in the lower reach of Seomjin River from May 2009 to November 2010. The collected fish from the six surveyed sites were 63 species belonging to 24 families, and 10 orders. Although species was different depending on sites, the numbers of individuals were not shown significance on sites. Locational dominant species were different. For example, the dominant species on May were Zacco platypus at W-1, Zacco temminckii at W-2, Acanthogobius flavimanus at W-3 and W-4, and Leiognathus nuchalis at W-5 and W-6. There is no seasonal differences in species. Species diversity was the best up to 2.64 on May at W-1 from 1.33 on November at W-6. As a result of an analysis about environmental factors for the numbers of fish species and individuals in each surveyed sites, the most effective groups were DO, BOD, and COD. The proportional difference was high on May than November between transient and asymptotic projections for population size and population growth rate for simulations starting at the current or theoretical stage distribution.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1323-1336
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• 2010

This study was carried out to determine marine environments and phytoplankton community around Mokpo harbour on March to November during the period of 2004-2009. The remarkable fluctuations of marine environments were shown around Mokpo harbour depending on monthly and yearly. Among seasons, summer was a great that was associated with extremely releasing the freshwater from Youngsan River Weir, contributing to effect the fluctuations of water quality. Nevertheless of monthly and yearly, the molecular ratio of N:P was always shown in above 16 that was mainly attributed to freshwater discharge on March to November. This indicates that phosphorus playes an important role in limiting factor as growth in phytoplankton. During this study, Skeletonema costatum was found to be richer than the other groups of diatoms in terms of abundance and species number. Mokpo harbour, with the presence of a narrow avenue for exchange with offshore waters, has limited growth in phytoplankton, but this species is able to well adapt and fast grow under even high level of suspended solid and low intensity of light compared with other species. The discharge of freshwater is associated with significantly fluctuation of marine environments in this region, but it does not affect the quantitative and qualitative distribution of phytoplankton. It is necessary to persistently monitor based on water quality and phytoplankton community.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.113.2-113.2
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• 2014

Methanol masers are divided into two classes, I and II. Class II methanol masers trace the disk-outflow systems of massive young stellar objects (YSOs), while class I methanol masers appear to trace the interaction regions of outflows with the ambient molecular gas. Class II masers have been extensively studied by single dishes, connected arrays, and VLBIs. Meanwhile, class I masers have been much less studied. They have not been detected by any VLBI facility. Thus they have been believed to have more extended structures than class II masers. We made fringe surveys of 44GHz class I methanol maser emission towards more than 150 massive YSOs with flux densities >10 Jy using the Korean VLBI Network (KVN), and detected fringes in ~10% of the sources. We performed follow-up imaging observations of the detected maser sources with KVN and KVN+VERA (KaVA). The observations aim to investigate the distribution and kinematics of 44GHz methanol maser features in each source at milli-arcsecond resolutions, and to understand what they trace. In this talk we will present the fringe survey and imaging results and our plans for further studies. Additionally, we will also introduce the preliminary results of single-dish polarization observations of water and class I methanol masers.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.121-124
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• 2006

A novel quantum chemical molecular dynamics program, 'Colors' was developed to simulate the electronic structure of rare earth-doped phosphor materials as well as the destruction processes of MgO protecting layer in plasma display panel (PDP). We have also developed a quantitative prediction method based on Monte Carlo simulation technique to evaluate the electrical conductivity of insulators, semiconductors, and metals as well as the spatial distribution of electron density by Colors code. All these original simulators enable us to study theoretically a variety of materials related to PDP.

• BMB Reports
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• v.48 no.8
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• pp.438-444
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• 2015

Lysosomal storage diseases (LSDs) are a group of inherent diseases characterized by massive accumulation of undigested compounds in lysosomes, which is caused by genetic defects resulting in the deficiency of a lysosomal hydrolase. Currently, enzyme replacement therapy has been successfully used for treatment of 7 LSDs with 10 approved therapeutic enzymes whereas new approaches such as pharmacological chaperones and gene therapy still await evaluation in clinical trials. While therapeutic enzymes for Gaucher disease have N-glycans with terminal mannose residues for targeting to macrophages, the others require N-glycans containing mannose-6-phosphates that are recognized by mannose-6-phosphate receptors on the plasma membrane for cellular uptake and targeting to lysosomes. Due to the fact that efficient lysosomal delivery of therapeutic enzymes is essential for the clearance of accumulated compounds, the suitable glycan structure and its high content are key factors for efficient therapeutic efficacy. Therefore, glycan remodeling strategies to improve lysosomal targeting and tissue distribution have been highlighted. This review describes the glycan structures that are important for lysosomal targeting and provides information on recent glyco-engineering technologies for the development of therapeutic enzymes with improved efficacy. [BMB Reports 2015; 48(8): 438-444]

• Parasites, Hosts and Diseases
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• v.56 no.4
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• pp.313-324
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• 2018

This article reviews Leptotrombidium deliense, including its discovery and nomenclature, morphological features and identification, life cycle, ecology, relationship with diseases, chromosomes and artificial cultivation. The first record of L. deliense was early in 1922 by Walch. Under the genus Leptotrombidium, there are many sibling species similar to L. deliense, which makes it difficult to differentiate L. deliense from another sibling chigger mites, for example, L. rubellum. The life cycle of the mite (L. deliense) includes 7 stages: egg, deutovum (or prelarva), larva, nymphochrysalis, nymph, imagochrysalis and adult. The mite has a wide geographical distribution with low host specificity, and it often appears in different regions and habitats and on many species of hosts. As a vector species of chigger mite, L. deliense is of great importance in transmitting scrub typhus (tsutsugamushi disease) in many parts of the world, especially in tropical regions of Southeast Asia. The seasonal fluctuation of the mite population varies in different geographical regions. The mite has been successfully cultured in the laboratory, facilitating research on its chromosomes, biochemistry and molecular biology.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.5
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• pp.596-603
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• 2003

Present study has been conducted to see the relative effects of adding N: to fuel-side and air-side on flame structure, soot formation and NOx emissions. Experiments were carried out to ascertain to what degree chemical kinetics and/or molecular transport effects can explain the differences in soot formation and NOx emission by studying laminar diffusion flames. Direct photograph was taken to see the flame structure. CARS techniques was used to get the flame temperature profiles. And spatial distribution of soot could be obtained by PLII method. CHEMKIN code was also used to estimate the global residence time to predict NOx emissions at each condition. Results from these studies indicate that fuel-side dilution is more effective than air-side dilution in view of NOx emissions. However, air-side dilution shows greater effectiveness over fuel-side dilution in soot formation. And turbulent mixing and heat transfer problems were thought to be considered in practical applications.