• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1839-1844
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• 2012

We have investigated binding between wild-type and mutant Heat Shock Factor (HSF) DNA binding domains (DBDs) with 17-bp HSE containing a central 5'-NGAAN-3' element by equilibrium analytical ultracentrifugation using multi-wavelength technique. Our results indicate that R102 plays critical role in HSE recognition and the interactions are characterized by substantial negative changes of enthalpy (${\Delta}H^0_{\theta}=-9.90{\pm}1.13kcal\;mol^{-1}$) and entropy (${\Delta}S^0_{\theta}=-12.46{\pm}3.77cal\;mol^{-1}K^{-1}$) with free energy change, ${\Delta}G^0_{\theta}$ of $-6.15{\pm}0.03kcal\;mol^{-1}$. N105 plays minor role in the HSE interactions with ${\Delta}H^0_{\theta}$ of $-2.54{\pm}1.65kcal\;mol^{-1}$, ${\Delta}S^0_{\theta}$ of $19.28{\pm}5.50cal\;mol^{-1}K^{-1}$ and ${\Delta}G^0_{\theta}$ of $-8.35{\pm}0.05kcal\;mol^{-1}$, which are similar to those observed for wild-type DBD:HSE interactions (${\Delta}H^0_{\theta}=-3.31{\pm}1.86kcal\;mol^{-1}$, ${\Delta}S^0_{\theta}=17.38{\pm}6.20cal\;mol^{-1}K^{-1}$ and ${\Delta}G^0_{\theta}=-8.55{\pm}0.06kcal\;mol^{-1}$) indicating higher entropy contribution for both wild-type and N105A DBD bindings to the HSE.

• Journal of the Korean Chemical Society
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• v.20 no.2
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• pp.118-128
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• 1976

The significant structure theory of liquids and the Bragg-Williams approximation of phase transition theory have been applied to the calculation of the thermodynamic properties of p-azoxyanisole which exhibits a liquid crystal phase of the nematic type. The isotropic phase was treated as a normal liquid; and for the nematic phase, in addition to its liquidity, the effect due to the arrangement of molecular-dipoles was considered. The liquidity of the p-azoxyanisole was described by the significant structure theory of liquids, and the Bragg-Williams approximation was used to consider the effect due to the arrangement of molecular-dipoles. The molar volume, vapor pressure, heat capacity at constant pressure, thermal expansion coefficient, compressibility, entropy and enthalpy change at the nematic-isotropic phase transition point, absolute entropy, and absolute Helmholtz free energy were calculated over the temperature range of the nematic and isotropic phases. The calculated results of the thermodynamic properties were compared with the experimental data.

• Journal of the Korean Chemical Society
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• v.8 no.2
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• pp.68-74
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• 1964

Water has the melting point, the boiling point, the heat of fusion, and the heat of vaporization all much higher than would be normally expected from the hydrogen compounds of the other members of the oxygen family. Another unique characteristic of ice-Ⅰ is its volume decrease which takes place in its melting. A number of significant efforts have been made in the past to explain these properties quantitatively. The authors, reasoning from the unusually great free surface energy of water and the characteristic volume change on melting, propose the structural model of liquid water as follows. On melting, fluidized vacancies of a molecular size are introduced. Thereupon, for the unusually great surface energy density, molecules surrounding the vacancies become to have close packed arrangement. But molecules not in direct contact with vacancies should still possess the original structure i. e., ice-Ⅰ. When a molecule adjacent to a vacancy jumps into the vacancy, the molecule attains the gaslike degree of freedom. Using the above model, the authors had developed the liquid partition function of water by applying the theory of significant structures in liquids. Molar volume, vapor pressure, entropy of fusion and entropy of vaporization were calculated over a wide temperature range. The results show good agreement with experimental observations.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.40.4-41
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• 2010

Using magnetic field and plasma moment data obtained by THEMIS satellites(A, D, and E), we selected 203 fast flow events accompanied by dipolarization in the near-Earth region( X(GSM) = -7 ~ -12 RE) and statistically examined their properties. It was found that most of the fast flows show the maximum velocity between 1 minute before dipolarization onset and 2 minutes after onset and proceed earthward and duskward. We also found that only the flows with low velocity of less than 400 km/s are observed at X > -8 RE, while the high velocity flows(as well as low velocity flows) are observed at the further tailward region(X < -8 RE). And most of the tailward flows are slow regardless of distance at X(GSM) = -7 ~ -12 RE. On the other hand, if we consider the fast flow as a bubble (Pontius and Wolf, 1990), the entropy parameter, PV5/3 is an important factor to describe the plasma sheet dynamics. Thus we investigated the relationship between the flow velocity and the amount of change in PV5/3 before and after dipolarization onset and found out that the dipolarizations with more depleted entropy parameter tend to show higher flow velocity. Also we examined how the magnetic field at geosynchronous orbit responds to the fast flow accompanied by dipolarization in the near-earth plasma sheet, using the measurements from GOES 11 and 12 statellites. We found that most of the fast flows do not reach geosynchronous orbit as suggested by Ohtani et al. (2006).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.1
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• pp.67-74
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• 2002

A phosphor for Plasma Display Panel, BaMgAl$_{10}$ O$_{17}$ :Eu$^{2+}$, showing a blue emission band at about 450nm was prepared by a solid-state reaction using BaCO$_3$, $Al_2$O$_3$, MgO, Eu$_2$O$_3$ as starting materials wish flux AlF$_3$. The study of the behaviour of Eu in BAM phosphor was carried out by the photoluminescence spectra and the Rietveld method with X-ray and neutron powder diffraction data to refine the structural parameters such as lattice constants, the valence state of Eu, the preferential site of Mg atom and the site fraction of each atom. The phenomenon of the concentration quenching was abound 2.25~2.3wt% of Eu due to a decrease in the critical distance for energy transfer of inter-atomic Eu. Through the combined Rietveld refinement, R-factor, R$_{wp}$, was 8.11%, and the occupancy of Eu and Mg was 0.0882 and 0.526 at critical concentration. The critical distance of Eu$^{2+}$ in BAM was 18.8$\AA$ at 2.25% Eu of the concentration quenching. Furthermore, c/a ratio was decreased to 3.0wt% and no more change was observed over that concentration. The maximum entropy electron density was found that the modeling of $\beta$-alumina structure in BaMgAl$_{10}$ O$_{17}$ :Eu$^{2+}$correct coincided showing Ba, Eu, O atoms of z= 1/4 mirror plane.e.ane.e.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.15-15
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• 2015

기존 기후변화 영향평가 불확실성 연구들은 거의 대부분 GCM의 불확실성이 가장 크다고 결론내리고 있으나, ES 불확실성과의 정량적 비교는 하지 못했으며, 기존 접근방법은 민감도 분석 수준에 머무르고 있다. 이에 본 연구에서는 기후변화 영향평가 각 단계별 불확실성을 포괄적으로 정량화하고 수행단계별 불확실성의 전파정도를 추정할 수 있는 새로운 approach를 제안하였다. 첫째, 전체 불확실성, 각 단계별 불확실성 증가 정도, 각 단계별 불확실성의 비율을 제시할 수 있는 새로운 approach를 제안하였다. 또한 불확실성을 정량적으로 추정할 수 있는 방법으로 maximum entropy(이하 ME)를 선정하였으며, 이를 본 연구에서 제시한 approach에서 적용성을 살펴보았다. 둘째, 본 연구에서는 기후변화 영향평가 불확실성 단계별 정량화를 위해 2개 배출시나리오, 4개 GCM 시나리오, 2개 상세화기법, 2개 수문모형을 사용하여 기본적 기후변화 영향평가 단계를 모두 수행하였다. 기존 approach에서는 GCMs의 변화율(89.34)이 가장 커 GCMs의 불확실성이 가장 큰 것으로 나타났으나 제시한 approach에서는 배출시나리오의 불확실성이 전체 대비 58.66 %로 기후변화 영향평가에서 가장 큰 불확실성 발생 원인으로 파악되었다. 모형 불확실성에서는 GCMs의 불확실성(전체 대비 33.57 %)이 가장 높게 나타났다. 또한 배출시나리오의 ME는 3.32, GCMs의 ME는 5.22, 상세화기법의 ME는 5.57, 수문모형의 ME는 5.66으로 단계적으로 불확실성이 증가하였다. 다음으로 유량과 강수를 이용하여 불확실성 정량화를 수행하였으며, 강수를 이용한 불확실성 정량화에서는 유량을 이용한 결과와 다르게 배출시나리오 다음으로 상세화기법의 불확실성이 큰 것으로 나타나 어떤 수문변수에 초점을 두느냐에 따라 불확실성 정량화저감 노력 대상이 달라질 수 있음을 제시하였다. 마지막으로 자연변동성에 의한 불확실성이 기후변화 전체 불확실성의 45.47 % 정도로 나타났으며, 이는 미래 기후변화에 의해 발생하는 불확실성이 과거 자연변동보다 2배 이상으로서, 기후변화에 의한 미래전망의 불확실성이 매우 크게 증가한다는 매우 중요한 결과를 제시하였다.

• Journal of Environmental Impact Assessment
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• v.31 no.3
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• pp.161-172
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• 2022

This study attempts to understand urban evolution characteristics through suburban development cases considered as a contemporary urban issue. Methods are (1) Urban Expansion Intensity Index (UEII) for the 9 cities in the Korea (1980-2010) & 49 cities in the US, (2) Morphological Spatial Pattern Analysis(MSPA) and Entropy for the developed areas in the Chicago Metro (2019). Results are (1) a suburban development could be understood the universal characteristics, (2) the characteristics of the whole region might be appeared to be in a different direction from the characteristics of its sub-cities. Implications are (1) Suburban expansion can be understood as a functionally well served urban change phenomenon and it is important to focus on the functions of sub-level cities, (2) the urban evolutionary perspective makes a difference from the developmental growth perspective. The extensive empirical studies will be beneficial for better understating of urban evolution.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.5
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• pp.13-24
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• 2023

Due to recent climate change, the amount of rainfall during the summer season in South Korea has been decreasing, leading to an increase in areas affected by frequent droughts. Droughts have the characteristic of occurring over a wide area and being unpredictable in terms of their onset and end, necessitating proactive research to cope with them. In this study, we conducted an assessment of agricultural drought vulnerability in Taean-gun, Chungcheongnam-do, focusing on irrigation facilities and paddy fields. The assessment criteria were meteorological impact, drought occurrence status, supplementary water supply capacity, and drought response capability, with nine specific indicators selected. The drought response capability was analyzed by applying a scoring system as a key component of the agricultural drought vulnerability assessment, while the other indicators were quantified using an entropy weighting technique. The results of the assessment showed that Anmyeon-eup and Taean-eup were the safest areas, while Wonbuk-myeon, Nam-myeon, and Gonam-myeon were the most vulnerable. It is expected that the findings can be utilized to enhance understanding and proactive measures for coping with agricultural drought, and to determine the priority of drought response in different regions.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.6
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• pp.1260-1271
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• 2001

The simulation program which predicts the gas behavior in a spark ignition engine has been developed and verified by the comparison with the experimental results foy the MPI engine, naturally aspirated and turbochared engines with a carburettor. First paper describes the calculations of the behavior of gas in the intake and exhaust system. The generalized method of characteristics including friction, heat transfer, area change and entropy gradients was used to analyse the pipe flow The constant-Pressure model was applied for the analysis of the flow through engine valved, and the constant-pressure perfect-mixing model was applied for the flow at manifold junction. The concept of the sudden area change was used for the muffler and catalytic convertor. Fer the plenum chamber in an MPI engine, constant-pressure model and constant-volume model were both examined. Through the comparison of predicted results with experiments, the simulation program was verified by showing good prediction of the behavior of IC engine qualitatively and quantitatively under wide range of operating conditions.

• Korean Journal of Materials Research
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• v.30 no.3
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• pp.136-141
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• 2020

The magnetocaloric effect (MCE), which is the reversible temperature change of magnetic materials due to an applied magnetic field, occurs largely in the vicinity of the magnetic phase transition temperature. This phenomenon can be used to induce magnetic refrigeration, a viable, energy-efficient solid-state cooling technology. Recently, Metal-organic frameworks (MOFs), due to their structural diversity of tunable crystalline pore structure and chemical functionality, have been studied as good candidates for magnetic refrigeration materials in the cryogenic region. In cryogenic cooling applications, MCE using MOF can have great potential, and is even considered comparable to conventional lanthanum alloys and magnetic nanoparticles. Owing to the presence of large internal pores, however, MOF also exhibits the drawback of low magnetic density. To overcome this problem, therefore, recent reports in literature that achieve high magnetic entropy change using a dense structure formation and ligand tuning are introduced.