• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1539-1544
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• 2007

1-Phenyl-3-p-fluorophenyl-5-p-chlorophenyl-2-pyrazoline has been synthesized and characterized by elemental analysis, IR, UV-Vis and X-ray single crystal diffraction. Density functional calculations show that B3LYP/6-311G** method can reproduce the structural parameters. The electronic absorption spectra have been predicted based on the optimized structure by using 6-311G** and 6-311++G** basis sets and compared with the experimental values. The results indicate that TD-DFT method can only predict the electronic absorption spectra of the system studied here approximately. On the basis of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between ,C0p,m,S0m,H0m and temperature.

• Journal of the Korean Society of Combustion
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• v.11 no.1
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• pp.19-26
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• 2006

Structure of edge flame established in a mixing layer, formed between two uniformly flowing pure $CH_4$ and pure $O_2$ streams, is numerically investigated by employing a detailed methane-oxidation mechanism. The numerical results exhibited the most outstanding distinction of using pure oxygen in the fuel-rich premixed-flame front, through which the carbon-containing compound is found to leak mainly in the form of CO instead of HC compounds, contrary to the rich $CH_4-air$ premixed flames in which $CH_4$ as well as $C_2H_m$ leakage can occur. Moreover, while passing through the rich premixed flame, a major route for CO production, in addition to the direct $CH_4$ decomposition, is found to be $C_2H_m$ compound formation followed by their decomposition into CO. Beyond the rich premixed flame front, CO is further oxidized into $CO_2$ in a broad diffusion-flame-like reaction zone located around moderately fuel-rich side of the stoichiometric mixture by the OH radical from the fuel-lean premixed-flame front. Since the secondary CO production through $C_2H_m$ decomposition has a relatively strong reaction intensity, an additional heat-release branch appears and the resulting heat-release profile can no longer be seen as a tribrachial structure.

• Korean Journal of Plant Resources
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• v.20 no.6
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• pp.530-539
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• 2007

Genetic variation and structure of 9 subpopulations of Symplocarpus renifolius Schott ex Tzvelev on Mt. Cheonma, in Korea, were determined via starch-gel electrophoresis. The genetic diversity at 10 loci for 8 isozymes ($P_{99}=66%,\;A=2.26,\;H_o=0.212,\;H_e=0.230$) was found to be considerably higher than that seen in other long-lived perennial plants. On the whole, the genotype frequencies were in accordance with Hardy-Weinberg expectations. Approximately 5%($\theta=0.049$) of the total variability was among subpopulations. The high levels of observed genetic diversity in S. renifolius were attributed to a universal outcrossing system and other specific factors like differences in age classes and widely scattered individuals around the main distribution. Heterozygosity was highest at a mid-range of elevation($450m{\sim}600m$). The lowest heterozygosity at lower elevation was attributed to the possible origin of seeds transported by water from upstream regions during the monsoon season. Spatial structure in a subpopulation evidenced a strong autocorrelation between closer individuals within $3{\sim}4m$ of distance. This was assumed to be attributable to the restricted seed dispersal characteristics of S. renifolius. In accordance with the findings generated in this study, some implications regarding the conservation of S. renifolius at the Mt. Cheonma were also presented.

• Korean Journal of Environment and Ecology
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• v.7 no.2
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• pp.164-171
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• 1994

To investigate the structure of natural forest at Nature Conservation Area in Tokyusan National Park, 29 plots (400$m^2$) set up with random sampling method. Four groups were classified by cluster analysis. High positive correlations was proved between Quernus mongolica and Fraxinus mandshurica, and Symplocos chinensis for. pilosa, and Lespedeza bicola, Acer tschonoskii var. rubripes and Taxus cuspidata, Magnolia sieboldii and Callicarpa japonica, Taxus cuspidata and Abies koreana, and high negative correlations was proved between Quercus mongolica and Acer tschonoskii var. rubripes, Taxus cuspidata, and Lonicera maackii. Species diversity(H') of investigated area was calculated 0.9969~1.2217.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1383-1387
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• 2013

The surface structure and electrochemical behavior of self-assembled monolayers (SAMs) prepared from benzenethiol (BT), cyclohexanethiol (CHT), and cyclopentanethiol (CPT) on Au(111) surface were examined by scanning tunneling microscopy (STM) and cyclic voltammetry (CV) to understand the influence of thiol molecular backbone structure on the formation and reductive desorption behavior of SAMs. STM imaging showed that BT and CPT SAMs on Au(111) surface formed at room temperature were mainly composed of disordered domains, whereas CHT SAMs were composed of well-ordered domains with three orientations. From these STM results, we suggest that molecule-substrate interaction is a key parameter for determining the structural order and disorder of simple aromatic and alicyclic thiol SAMs on Au(111). In addition, the reductive desorption peak potential for BT SAMs with aromatic rings was observed at a less negative potential of -566 mV compared to CHT SAMs (-779 mV) or CPT SAMs (-775 mV) with aliphatic cyclic rings. This reductive desorption behavior for BT SAMs is due to the presence of p-orbitals on the aromatic rings, which promote facile electron transfer from the Au electrode to BT as compared to CHT and CPT. We also confirmed that the reductive desorption behavior for simple alicyclic thiol SAMs such as CHT and CPT SAMs on Au electrodes was not significantly influenced by the degree of structural order.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.6
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• pp.328-334
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• 2000

A lithium ion secondary battery using carbon as a negative electrode has been developed. Further improvements to increase the cell capacity are expected by modifying the structure of the carbonaceous material. There are hopes for the development of large capacity lithium ion secondary batteries with long cycle, high energy density, high power density, and high energy efficiency. In the present paper, needle cokes from petroleum were examined as an anode of lithium ion secondary battery. Petroleum cokes, MCL(Molten Caustic Leaching) treated in Korea Institute Energy Research, were carbonized at various temperatures of 0, 500, 700, $19700^{\circ}C$ at heating rate of $2^{\circ}C$/min for lh. The electrolyte was used lM liPF6 EC/DEC (1:1). The voltage range of charge & discharge was 0.0V(0.05V) ~ 2.0V. The treated petroleum coke at $700^{\circ}C$ had an initial capacity over 560mAh.g which beyond the theoretical maximum capacity, 372mAh/g for LiC6. This phenomena suggests that carbon materials with disordered structure had higher cell capacity than that the graphitic carbon materials.

• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.432-436
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• 1994

Monomeric rhodium and iridium-diaryltetrazene complexes $Cp^*$M(RNN=NNR)($Cp^*$=1,2,3,4,5-pentamethylcyclope ntadienyl; M=Rh, Ir; R=Ph, 4-tolyl) have been synthesized from [$Cp^*MCl_2]_2$(M=Rh, Ir) and 2 equiv. of $[Li(THF)_x]_2(RN_4$R) in benzene. We have determined the crystal structure of (${\eta}^5$-pentamethylcyclopentadienyl)diphenyltetrazene iridium by using graphite-monochromated Mo-$K_a$ radiation. The compound was crystallized in the monoclinic space group $P2_{1/c}$ with a=13.781(3), b=9.035(l), c=17.699(3) ${\AA}$, and ${\beta}=111.93(l)^{\circ}$. An X-ray crystal structure of complex 1 showed a short N(2)-N(3) distance ($1.265 {\AA}$) consistent with the valence tautomer A with Ir(III) rather than Ir(I). All complexes are highly colored and decompose on irradiation at 254 nm. Electrochemical studies show that complex 1 displays a quasi-reversible reduction.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1199-1209
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• 2023

Where concrete structures are designed to have a service life of over 100 years, their performance must be monitored, for the prediction models available are fraught with uncertainties that need to be eliminated. The present study was conducted to meet that need by monitoring a pilot structure for low and intermediate radioactive waste storage. Long-term operation of the sensors was observed to be adequate to determine the value of the parameters that characterise structural durability, such as corrosion current density. The parameters analysed were correlated to calculate their reciprocal impact: where applied in conjunction with artificial intelligence tools, temperature, for instance, was found suitable for finding activation energy and expansion coefficients and detecting outliers. The results showed the pilot structure to perform satisfactorily.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.68.1-68.1
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• 2021

We study galaxy evolution with the large-scale environment with confirmed galaxy clusters from multi-object spectroscopy (MOS) observation. The observation was performed with Inamori Magellan Areal Camera and Spectrograph (IMACS) mounted on the 6.5 m Magellan/Baade telescope in Las Campanas Observatory. With the MOS observation, we spectroscopically confirm 34 galaxy clusters, including three galaxy clusters discovered in Kim et al. (2016) and 11 of them have halo mass of > 10^14.5 M_◉. Among the confirmed clusters, 12 galaxy clusters are part of large-scale structure at z ~ 0.9, and their size stretches to 40 Mpc co-moving scale. In this study, we checked the 'web feeding model,' which postulates that more linked (with their environment) galaxy clusters have less quenched populations by investigating the correlation between properties of confirmed galaxy clusters and the large-scale structure environment. Lastly, we found that galaxy clusters that make up the large-scale structure have larger and widely spread values of total star formation density (ΣSFR/M_halo) than typical clusters at similar redshifts.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.1059-1066
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• 2011

We introduce the concept of fuzzy S-weakly r-M-continuous functions on fuzzy r-minimal spaces, and investigate some characterizations of such functions and the relations between the continuity and fuzzy r-minimal compactness on fuzzy r-minimal spaces.