• Journal of the Korean Ceramic Society
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• v.23 no.5
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• pp.61-66
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• 1986

The gas mixtures ($H_2$/$N_2$, He/$N_2$) having a high thermal conductivity allow the heat generated by the nitriding exotherm to be dissipated from the compact in to the nitriding atmosphere permitting a more accurate control of temperature and produces a more uniform microstructure. In order to observe the effect of the mixed gas atmosphere on the microsturcture of RBSN. the specimen was nitrided in the mixed gas atmosphere which was containe up to 50vol% $H_2$ or He for 0-12 hrs at 135$0^{\circ}C$. The addition of hydrogen to nitrogen gas resulted in the growth of a-needle at the early stage of nitrding increase of the reaction rate and a finer and more uniform microstructure. in case of the addition of helium the behaviour of reaction was similar to the one with pure nitrogen. As the amount of helium was increased a coarse microstructure was formed.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.662-665
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• 2002

This paper describes a novel converter to implement high-speed binary-to-residue conversion for moduli 2$^{n}$ - 1, 2$^{n}$ , 2$^{n}$ +2$^{\alpha}$/($\alpha$$\in$｛0,1,…,n-1｝) without using look-up table. In our implementation, the high-speed converter can be achieved, because of the modulo addition time is independent of the word length of operands by using the Signed-Digit (SD) adders inside the modulo adders. For a LSI implementation of residue SD number system with ordinary binary system, the proposed binary-to-residue converter is the efficient circuit.cient circuit.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3793-3796
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• 2012

A novel 3D compound $\{[Cu(L)(H_2O)_4][Cu_2(SIP)_2(L)_2]\}{\cdot}2H_2O$ (1) (L = N,N-bis(4-pyridinecarboxamide)-1,4-butane, SIP = 5-sulfoisophthalate) is hydrothermally synthesized. X-ray diffraction analysis reveals that compound 1 is composed of 2D anionic $[Cu_2(SIP)_2(L)_2]_n{^{2n-}}$ double-layers and discrete 1D cationic $[CuL(H_2O)_4]_n{^{2n+}}$ polymeric chains, which represents a rare 3D polypseudo-rotaxane MOF from intercalation of 1D and 2D framework. In addition, the luminescent property and electrochemical behavior of compound 1 have been investigated.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.97.2-97.2
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• 2018

This study formed a hard TiAlSiWN coating layer using Ti, Al, Si and W raw powders that were mechanically alloyed and refined. The TiAlSi and TiAlSiW coating targets were fabricated using a single PCAS process in a short time with the optimal sintering conditions. The coating targets were deposited on the WC substrate by forming coating layers using TiAlSiN and TiAlSiWN nitride nano-composite structures with an AIP process. The properties of the nitride nano-composite coating layers were compared according to the addition of W. The microstructure of the nitride nano-composite coating layer was analyzed, focusing on the distribution of the crystalline phases, amorphous phases ($Si_3N_4$), and growth orientation of the columnar crystal depending on the addition of W. The mechanical properties of the coating layers were exhibited a hardness of approximately $3,000kg/mm^2$ and adhesion of about 117.77N in the TiAlSiN. In particular, the TiAlSiWN showed excellent properties with a hardness of more than $4,300kg/mm^2$ and an adhesion of about 181.47N.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.206-215
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• 2009

This experiment was carried out to evaluate performance and carcass characteristics of 40 crossbred young bulls ($Zebu{\times}European$) finished in a feedlot under two roughage sources (Bermuda grass hay or sorghum silage) with or without the addition of yeast (Saccharomyces cerevisae). The bulls were 20 months old, their initial average weight was 356 kg and they were allocated into four groups of ten animals. The experimental diets were Bermuda grass, Bermuda grass+yeast, sorghum silage and sorghum silage +yeast. Animal performance and carcass characteristics were not influenced by roughage source or yeast addition. The average daily weight gain was 1.50 kg, dry matter intake (DMI) was 11.1 kg/d, DMI as percentage of liveweight was 2.60% and feed dry matter conversion was 7.70. The mean dressing percentage was 52.0% and hot carcass weight was 268 kg. Carcass conformation was classified between good-minus to good. Carcass length (137 cm), leg length (72.9 cm) and cushion thickness (26.6 cm) were not influenced by treatments. The average fat thickness was 3.80 mm and the Longissimus muscle area was 66.9 $cm^{2}$. The classification of color, texture and marbling were slightly dark red to red, fine and slight-minus to light-typical, respectively. The mean percentage of bone, muscle and fat in the carcass was 15.5%, 62.3% and 22.5%, respectively. Yeast addition increased ${\gamma}$-linolenic fatty acid (0.15 vs. 0.11%) deposition. Bermuda grass hay increased deposition of ${\alpha}$-linolenic (0.49 vs. 0.41%), arachidonic (2.30 vs. 1.57%), eicosapentaenoic (0.41 vs. 0.29%), docosapentaenoic (0.80 vs. 0.62%), docosahexaenoic (0.11 vs. 0.06%) and n-3 fatty acids, and reduced n-6: n-3 ratio in meat, when compared to sorghum silage treatments. The treatments had no effect on saturated fatty acids (49.5%), polyunsaturated fatty acids (11.8%), n-6 fatty acids (9.87%), n-3 (1.61%) and PUFA:SFA ratio (0.24). Monounsaturated fatty acid levels were higher on sorghum silage (40.7 vs. 37.7%). The addition of yeast caused higher n-6: n-3 ratio (7.28 vs. 5.70) than treatments without yeast.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.318-323
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• 1992

Following seven new nucleophilic adducts of sulfilimine compounds were prepared by the addition of 1-methyl-5-mercapto-1,2,3,4-tetrazole to vinylsulfilimine derivatives; S-Phenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-tolyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-m-tolyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-chlorophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-bromophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine, S-p-methoxyphenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine and S-p-nitrophenyl-S-2-(1-methyl-1,2,3,4-tetrazole-5-thio)-ethyl-N-p-tosylsulfilimine. The structures of these adducts were confirmed by elemental analyses, MP, UV, IR-and NMR-Spectra.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1128-1133
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• 2004

A comprehensive experimental and numerical study has been conducted to understand the influence of $CH_{3}Cl$ addition on $CH_{4}/O_{2}/N_{2}$ premixed flames under the oxygen enrichment. The laminar flame speeds of $CH_{4}/CH_{3}Cl/O_{2}/N_{2}$ premixed flames at room temperature and atmospheric pressure are experimentally measured using Bunsen nozzle flame technique, varying the amount of $CH_{3}Cl$ in the fuel, the equivalence ratio of the unburned mixture, and the level of the oxygen enrichment. The flame speeds predicted by a detailed chemical kinetic mechanism employed are found to be in excellent agreement with those deduced from experiments. As $CH_{3}Cl$ addition is increased temperature at the postflame is not almost varied but the heat release rate and $EI_{NO}$ are decreased. The function of $CH_{3}Cl$ as inhibitor on hydrocarbon flames becomes weakened as the level of the oxygen enrichment is increased from 0.21 to 0.5.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.306-317
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• 2014

This study has been executed to understand the additional and removal processes of nutrients in the Saemangeum Salt-water Lake, and discussed with other monthly-collected environmental parameters such as water temperature, salinity, dissolved oxygen, suspended solids, and Chl-a from 2008 to 2010. $NO_3$-N, TP, $PO_4$-P, and DISi showed the removal processes along with the salinity gradients at the surface water of the lake, whereas $NO_2$-N, $NH_4$-N, and Chl-a showed addition trend. In the bottom water all water quality parameters except $NO_3$-N appeared addition processes indicating evidence of continuous nutrients suppliance into the bottom layer. The mixing modelling approach revealed that the biogeochemical processes in the lake consume $NO_3$-N and consequently added $NH_4$-N and $PO_4$-P to the bottom water during the summer seasons. The $NH_4$-N and $PO_4$-P appeared strong increase at the bottom water of the river-side of the lake and strong concentration gradient difference of dissolved oxygen also appeared in the same time. DISi exhibited continuous seasonal supply from spring to summer. Internal addition of $NH_4$-N and $PO_4$-P in the river-side of the lake were much higher than the dike-side, while the increase of DISi showed similar level both the dike and river sides. The temporal distribution of benthic flux for DISi indicates that addition of nutrients in the bottom water was strongly affected by other sources, for example, submarine ground-water discharge (SGD) through bottom sediment.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.2
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• pp.157-163
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• 2014

Let {$X_i$, $1{\leq}i{\leq}n$} be a sequence of i.i.d. sequence of positive random variables with common absolutely continuous cumulative distribution function F(x) and probability density function f(x) and $E(X^2)$ < ${\infty}$. The random variables X + Y and $\frac{(X-Y)^2}{(X+Y)^2}$ are independent if and only if X and Y have gamma distributions. In addition, the random variables $S_n$ and $\frac{\sum_{i=1}^{m}(X_i)^2}{(S_n)^2}$ with $S_n=\sum_{i=1}^{n}X_i$ are independent for $1{\leq}m$ < n if and only if $X_i$ has gamma distribution for $i=1,{\cdots},n$.

• East Asian mathematical journal
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• v.31 no.5
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• pp.695-706
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• 2015

Let ${\mathcal{H}}$ be an infinite dimensional complex Hilbert space, and let $B({\mathcal{H}})$ be the algebra of all bounded linear operators on ${\mathcal{H}}$. Recall that an operator $T{\in}B({\mathcal{H})$ has property B(n) if ${\mid}T^n{\mid}{\geq}{\mid}T{\mid}^n$, $n{\geq}2$, which generalizes the class A-operator. We characterize the property B(n) of weighted shifts $S_{\lambda}$ over (${\eta},\;{\kappa}$)-type directed trees which appeared in the study of subnormality of weighted shifts over directed trees recently. In addition, we discuss the property B(n) of weighted shifts $S_{\lambda}$ over (2, 1)-type directed trees with nonzero weights are being distinct with respect to $n{\geq}2$. And we give some properties of weighted shifts $S_{\lambda}$ over (2, 1)-type directed trees with property B(2).