• Title/Summary/Keyword: ${\L}C$

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Ring-Opening Polymerization of $\varepsilon$-Caprolactone and Cyclohexene Oxide Initiated by Aluminum $\beta$-Ketoamino Complexes: Steric and Electronic Effect of 3-Position Substituents of the Ligands

  • Liu, Binyuan;Li, Haiqing;Ha, Chang-Sik;Kim, Il;Yan, Weidong
    • Macromolecular Research
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    • v.16 no.5
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    • pp.441-445
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    • 2008
  • A series of aluminum complexes supported by $\beta$-ketoamino, ligand-bearing, 3-position substituents $LAlEt_2$ ($L=CH_3C(O)C(Cl)=C(CH_3)NAr\;(L_1)$, $L=CH_3C(O)C(H)=C(CH_3)NAr\;(L_2)$, $L=CH_3C(O)C(Ph)=C(CH_3)NAr\;(L_3)$, and $L=CH_3C(O)C(Me)=C(CH_3)NAr\;(L_4)$, $Ar=2,6-^iPr_2C6H_3$) were synthesized in situ and employed in the ring-opening polymerization (ROP) of $\varepsilon$-caprolactone ($\varepsilon$-CL) and cyclohexene oxide (CHO). The 3-position substituents on the $\beta$-ketoamino ligand backbone of the aluminum complexes influenced the catalyst activity remarkably for both ROP of $\varepsilon$-CL and CHO. Aluminum $\beta$-ketoamino complexes displayed different catalytic behavior in ROP of $\varepsilon$-CL and CHO. The order of the catalytic activity of $LAlEt_2$ was $L_1AlEt_2$>$L_2AlEt_2$>$L_3AlEt_2$>$L_4AlEt_2$ for ROP of $\varepsilon$-CL, being opposite to the electron-donating ability of the 3-position substituents on the $\beta$-ketoamino ligand, while the order of the catalytic activity for ROP of CHO was $L_1AlEt_2$>$L_3AlEt_2$>$L_4AlEt_2$>$L_2AlEt_2$. The effects of reaction temperature and time on the ROP were also investigated for both $\varepsilon$-CL and CHO.

Studies on the Chemical Structure of the New Polysaccharide C - (The New Polysaccharides of Gum Tragacanth. II) - (Tragacanth gum 의 신다당류(新多糖類) C 의 화학구조(化學構造) - Tragacanth gum의 신다당류(新多糖類)에 관(關)한 연구(硏究) 제2보(第二報) -)

  • Lee, Sung-Hwan
    • Applied Biological Chemistry
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    • v.3
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    • pp.25-48
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    • 1962
  • The polysaccharide C prepared from gum tragacanth powder (U. S. P. grade) by the precipitation method with 85% ethanol was a neutral polysaccharide, $[{\alpha}]^{30}_D-72.2$. The polysaccharide C consisted of L-rhamnose, D-xylose, L-arabinose and D-galactose in the molar ratio 2:1:17:9 (Table 1, 2, 3, ). The polysaccharide C was methylated with dimethylsulphate and 40% NaOH, and Purdies regent. The hydrolyzate of fully methlated product ($[{\alpha}]^{22}_D-102$ in chloroform, the methoxy content 40.6%) was composed of 2, 3, 5-tri-O-methyl-L-arabofuranose (I), 3,4-di-O-methyl-L-rhamnopyranose (II), 2,3-di-O-methyl-D-xylose (III), 2,3,4-tri-O-methyl-D-galactopyranose (IV), 2,4-di-O-methyl-L-arabopyranose (?), 2,4-di-O-methyl-D-galactose(VI), 2-O-methyl-D-arabinose (VII), and L-arabopyranose(VIII) (Table 4, 5, and Fig. 4). The first partial hydrolysis (A) of the polysaccharide C with 0.05N-HCl for 4.5 hours at $80-85^{\circ}C$ released only L-arabinose: the second hydrolysis (B) with 0.1N-HCl for 5 hours at $80-85^{\circ}C$, L-arabinose and D-galactose; and the third hydrolysis (C) with 0.3N-HCl at $90-95^{\circ}C$ in sealed tube, L-rhamnose, D-xylose, L-arabinose and D-galactose. From the unhydrolyzate A' were found L-rhamnose, D-xylose, L-arabinose, and D-galactose; from B' L-rhamnose, d-xylose, L-arabinose and D-galactose; and from C' D-xylose and D-galactose respectively (Table 6). The periodate consumption and formic acid production of the polysaccharide C were measured at various time intervals. After 120 hours periodat was consumed by 1.23 mole per $C_5H_8O_4$ and formic acid was produced 0.78 mole per $C_5H_8O_4$ (Table 7). Although a definite chemical structure for this polysaccharide C may not be formulated, experimental data, especially, from methylation, partial hydrolysie and determination of its molar ratio, and periodate analysis showed that the polysaccharide C is a highly branched polysaccharide and would be constructed of galactoaraban as a main chain residue and L-arabofuranose, D-galactopyranosyl $(1{\rightarrow}1)$-L-arabofuranose, D-xylopyranosyl $(1{\rightarrow}2)$-L-rhamnopyranosyl $(1{\rightarrow}1)$-L-arabofuranose, and L-rhamnopyranosyl $(1{\rightarrow}1)$-arabofuranose, and D-galactopyranosyl-$(1{\rightarrow}2)$-L-arabopyranosyl-$(1{\rightarrow}1)$-I-arabofuranose as a branch chain or end group (page 21).

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Abstracts of Research Papers in Poultry Science (가금학 분야 연구 논문 초록)

  • 세계가금학회한국지부
    • Korean Journal of Poultry Science
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    • v.4 no.1
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    • pp.66-74
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    • 1977
  • 닭의 혈액상에 관한 발표는 많으나 아직 우리나라에서의 보고는 거의 없다. 이에 산난능력이 우수한 닭과 병계에 대한 앞으로의 혈액학적 연구를 위한 기초적자료를 얻고저 임상적으로 건강한 소위 한국 재내종(LCH)과 백색레그혼 (WLH)암탉의 정상 혈액학치 즉 적혈구, 백혈구, 혈색소, 헤마토크리프. 평균적혈구 용적, 평균 적혈구 혈색소량. 평균 적혈구 혈색소 농도 등을 조사하였다. 1 R.B.C.는 L.C.H.에서 3.18$\pm$0.10million per c$\mu$. mm였으며 W.L.H.는 3.23$\pm$0.05였다. 2. W.B.C.는 L.C.H에서 42.17$\pm$3.35, thousand per. c$\mu$mm였으며 W.L.H.는 35.64$\pm$2.89였다. 3. Hemoglobin치는 L.C.H.에서 11.24$\pm$0.30gm per 100$m\ell$였으며 WL.H.는 38.40$\pm$0.75였다. 4. Hematocrit치는 L.C.H.에서 34.00$\pm$0,98 percent였으며, W.L.H.는 33.40$\pm$0.75였다. 5. M.C.V.는 L.C.H에서 103.66$\pm$1.22 c$\mu$ 였으며, W.L.H.는 103.32$\pm$1.28이였다. 6. M.C.H,는 C.L.H.에서 34.19$\pm$0.41 $\mu$ $\mu\textrm{g}$9였으며. W.L.H,는 34.37$\pm$0.31이었다. 7. M.C.H.C는 L.C.H.에서 33.09$\pm$0.22 percent였으며, W.L.H.는 33.25$\pm$0.36 0.36이었다. (중략)

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Performance Analysis of Wideband DS-CDMA System using Hybrid SC/$MRC-L_c$/L Diversity Received (하이브리드 SC/$MRC-L_c$/L 다이버시티 수신 광대역 DS-CDMA 시스템의 성능 해석)

  • 김영철;조성준
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.489-493
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    • 2004
  • 본 논문에서는 다중경로 페이딩 환경에서의 하이브리드 (Hybrid) SC/MRC-L$_{c}$/L 다이버시티 수신기법과 콘볼루션 부호화 기법을 각각 이용할 때의 광대역 DS-CDMA 시스템의 성능을 구하였다. 다중경로 페이딩으로는 라이시안 페이딩 채널을 가정하였고, 다중사용자간섭의 영향을 함께 분석하였다. 그리고 하이브리드 SC/MRC-L$_{c}$/L 다이버시티 기법과 론볼루션 부호화 기법을 채용하여 성능개선정도를 비교, 분석하였다. 하이브리드 SC/MRC-L$_{c}$/L 수신에서는 각각의 반송파에 대하여 상관을 취하고 상관기 출력들 중에서 가장 큰 신호성분을 L$_{c}$개만큼 선택하여 최대비 합성하며, 콘볼루션 부호화는 다중경로 페이딩 및 다중접속간섭에 의하여 발생된 오류를 정정 및 검출한다. 분석 결과, 콘볼루션 부호화의 경우는 부호이득과 전력제한 시스템의 trade off를 고려한 부호화율의 선택과 하이브리드 SC/MRC-L$_{c}$/L 수신의 경우, 다이버시티 가지의 증가는 선택의 폭이 커져 성능개선은 이루어지지만 가지의 배수가 동일할 경우 가지의 수가 적은 것이 시스템의 복잡성과 경제적인 면에서 효율적임을 알 수 있었다

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THE SPHERICAL NON-COMMUTATIVE TORI

  • Boo, Deok-Hoon;Oh, Sei-Qwon;Park, Chun-Gil
    • Journal of the Korean Mathematical Society
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    • v.35 no.2
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    • pp.331-340
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    • 1998
  • We define the spherical non-commutative torus $L_{\omega}$/ as the crossed product obtained by an iteration of l crossed products by actions of, the first action on C( $S^{2n+l}$). Assume the fibres are isomorphic to the tensor product of a completely irrational non-commutative torus $A_{p}$ with a matrix algebra $M_{m}$ ( ) (m > 1). We prove that $L_{\omega}$/ $M_{p}$ (C) is not isomorphic to C(Prim( $L_{\omega}$/)) $A_{p}$ $M_{mp}$ (C), and that the tensor product of $L_{\omega}$/ with a UHF-algebra $M_{p{\infty}}$ of type $p^{\infty}$ is isomorphic to C(Prim( $L_{\omega}$/)) $A_{p}$ $M_{m}$ (C) $M_{p{\infty}}$ if and only if the set of prime factors of m is a subset of the set of prime factors of p. Furthermore, it is shown that the tensor product of $L_{\omega}$/, with the C*-algebra K(H) of compact operators on a separable Hilbert space H is not isomorphic to C(Prim( $L_{\omega}$/)) $A_{p}$ $M_{m}$ (C) K(H) if Prim( $L_{\omega}$/) is homeomorphic to $L^{k}$ (n)$\times$ $T^{l'}$ for k and l' non-negative integers (k > 1), where $L^{k}$ (n) is the lens space.$T^{l'}$ for k and l' non-negative integers (k > 1), where $L^{k}$ (n) is the lens space.e.

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Biosynthesis of Saponins in Panax ginseng (고려인삼 사포닌류의 생합성에 관한 연구)

  • Hong, Seok-Ju;Lee, Yong-U;Ju, Chung-No
    • Journal of Ginseng Research
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    • v.11 no.2
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    • pp.136-144
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    • 1987
  • Biosynthesis of saponins from acetate, mevalonate and squalene using root slices of panax ginseng C.A. Meyer was investigated. The sliced roots (2g) were incubated with the reaction mixture containing 20 M sodium acetate ($500\mu$Ci [U-$^{l4}C$]-acetate),10 mM mevalonate ($25\mu$Ci [2-$^{l4}C$]-mevalonate) or 10 mM swidme ($10\mu$Ci [4,8,12,13,17,21-$^3H$]-squalene) respectively at $30^{\circ}C$ for 72 hours. Biosynthesis of labelled ginseng saponine from [U-l4C]-acetate, [2-$^{l4}C$]-mevalonate and [4,8,12,13,17,21-$^3H$]-squalene was confirmed by autoradiography. Analysis of the products from [U-$^{l4}C$]-acetate by T.L.C. showed that the % radioactivities in panaxadiol, panaxatriol, squalene and mevalonate were found to be 2.1%, 2.7%, 2.6% and 0.2% respectively. Some of the sugars were also highly labelled. Analysis of the products from [2-$^{l4}C$]-mevalonate by T.L.C. showed that squalene was highly labelled and the products from [4,8,12,13,17,21-$^3H$]-squalene showed that panaxadiol, panaxatriol and sterol were highly labelled. From the above results, it was suggested that saponine might be synthesized from acetate via mevalonate-squalene route as expected in ginseng root.

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The Design and implementation of LVC Integrated Architecture Technology building division-level L-V-C Interoperability Training System (사단급 L-V-C연동훈련체계 구축을 위한 LVC통합아키텍쳐기술 설계 및 구현)

  • Won, Kyoungchan;Koo, JaHwan;Lee, Hojun;Kim, Yong-Pil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.5
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    • pp.334-342
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    • 2021
  • In Korea, the training is performed through independent environments without interoperability among L-V-C systems. In the L system, training for large units is limited due to civil complaints at the training grounds and road restrictions. The V system is insufficient in training related to tactical training, and the C system lacks practicality due to a lack of combat friction elements. To achieve synchronicity and integration training between upper and lower units, it is necessary to establish a system to ensure integrated training for each unit by interoperating the currently operating L, V, and C systems. The interoperability between the C-C system supports Korea-US Combined Exercise. On the other hand, the actual development of the training system through the interoperability of L, V, and C has not been made. Although efforts are being made to establish the L, V, and C system centering on the Army, the joint composite battlefield and LVC integrated architecture technology are not yet secured. Therefore, this paper proposes a new plan for the future training system by designing and implementing the LVC integrated architecture technology, which is the core technology that can build the L-V-C interoperability training system. In conclusion, a division-level L-V-C interoperability training system can be established in the future by securing the LVC integrated architecture technology.

Study on Sensory Papillae of Metagonimus yokogawai Cercaria (Metagonimus yokogawai 세르카리아의 감각유두에 관한 연구)

  • 김재진;민득영소진탁
    • Parasites, Hosts and Diseases
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    • v.22 no.1
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    • pp.11-20
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    • 1984
  • A number of studies on the papillae of cercariae of trematodes reported that the papillar patterns (or chaetotaxy) of cercariae might be an excellent method to attain better understanding of the digenetic trematodes (Richard, 1971 ; Short and Cartrett, 1973; Bayssade-Dufour, 1979) . The present study was aimed to determine the number, distribution pattern and structure of the sensory papillae of Metagonimus yokogawai cercariae, and to elucidate the chaetotaxy of this digenetic trematode. M. yokogawai cercariae were pipetted from a vial in which infected snails (Semisulcospira libertina) had been kept for 3 hours. The snails were collected from an endemic area of M. yokogawai, Boseong river in west-southern part of Korea. Observations of papillae were based on light microscopy of those stained with silver nitrate, and on scanning electron microscopy The results are summarized as follows: 1, All papillae observed were uniciliated. 2. Cilia in anterior tip were shorter than the others in other portions. 3. The body papillae were arranged in essentially symmetrical patterns, Total number of the papillae was 126(63 pairs) in average; anterior tip 40(20 pairs), ventral 20(10 pairs), lateral 42(21 pairs), and caudal 8(4 pairs). 4. The chaetotany of M. yokogawai cercaria was: Ci cycle ($3+3C_{I}V,{\;}2+2C_{I}L,{\;}2+3C_{I}D),{\;}C_{II}{\;}cycle(2C_{II}V,{\;}1C_{II}L,{\;}2C_{II}D),{\;}C_{lll}{\;}cycle{\;}(1+lC_{III}V,{\;}1C_{IlI}L),{\;}C_{IV}{\;}cycle{\;}(1C_{IV}V,{\;}IC_{lV}L){\;}in{\;}cephalic{\;}region:{\;}A_I(1A_{IV}V,{\;}1+2A_{I}L,{\;}1A_{I}D),{\;}A_{II}(1A_{II}V,{\;}1+3A_{II}L,{\;}1A_{II}D),{\;}A_{III}(1A_{III}V,{\;}1+1A_{III}L,{\;}1A_{III}D){\;}and{\;}A_{IV}(1A_{IV}V,{\;}2A_{IV}L)$ in antacetabular region: $1M_{I}V{\;}and{\;}2M_{I}L$ in median: $1+1P_{I}L,{\;}1P_{II}L,{\;}1P_{II}D,{\;}1P_{III}L,{\;}1P_{IV}L{\;}and{\;}1P_{IV}D$ in postacetabular region: 2-2-2-2 in caudal region.

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Rapid Acquisition of CM and CL Code for GPS L2C Software Receivers

  • Kwon, Keum-Cheol;Shim, Duk-Sun
    • Journal of Electrical Engineering and Technology
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    • v.6 no.5
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    • pp.723-730
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    • 2011
  • The GPS modernization program offered a new civil signal on the L2 band, and the first modernized GPS Block IIR satellite was launched in September 2005. Currently, eight GPS Block IIRM satellites and two Block IIF satellites transmit L2C signal. The L2C signal contains two codes of CM and CL that are much longer than the L1 C/A code. Thus, the acquisition of the CM and CL codes takes more time compared with that of L1 C/A code. Under the assumption that the L2C signal is strong enough for detection, this paper suggests rapid acquisition methods for the GPS L2C signals for software receivers and compares its performance with that of other methods.

Identification and Tolerance-Test to Digestive Fluids of Lactobacilli Isolated from Korean Liquid Yogurts (국내 액상발효유에서 분리한 유산균의 동정 및 소화관액 내성조사)

  • So, Myeong-Hwan
    • Korean Journal of Food Science and Technology
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    • v.17 no.3
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    • pp.192-196
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    • 1985
  • Eight strains of Lactobacilli(a, b, b', c, d, e, f and g) were isolated from seven Korean liquid-yogurts(A, B, C, D, E, F and G), and identification and tolerance-test to digestive fluids were carried out. Isolate a from yogurt A and isolate a from yogurt E were identified as L. casei, isolate b from yogurt B as L. acidophilus, isolate d from yogurt D as L. bulgaricus, isolate f from yogurt F as L. helveticus, and isolate b' from yogurt B, isolate c from yogurt C and isolate g from yogurt G as L. jugurti, respectively. Isolate f(L. helveticus) and c(L. jugurti) showed high tolerance to artificial gastric juice but didn't to bile acid. Isolate b(L. acidophilus), a(L. casei), and e(L. casei) showed high tolerance to both artificial gastric juice and bile acid, but isolate d(L. bulgaricus), b'(L. jurgurti) and g(L. jugurti) did not.

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