• 대한화학회지
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• 제57권5호
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• pp.612-617
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• 2013

The versatile, hitherto unreported 3-(4-(2-phenyldiazenyl)-2-oxo-2H-chromen-3-yl)-3-oxopropanenitrile 3 was prepared by two convenient routes: either by the reaction of ethyl 4-(2-phenyldiazenyl)-2-oxo-2H-chromen-3-carboxylate 2 with acetonitrile in the presence of sodium hydride or by treatment of 4-(2-phenyldiazenyl)-3-(2-bromoacetyl)-2H-chromen-2- one 5 with potassium cyanide. Reaction of 3 with heterocyclic diazonium salts 6, 7, 14 and 17 furnished the corresponding hydrazones 8, 9, 15 and 18. The latter hydrazones underwent intramolecular cyclization into the corresponding pyrazolo[5,1- c]-1,2,4-triazine 10, 1,2,4-triazolo[5,1-c]-1,2,4-triazine 11, 1,2,4-triazino[4,3-b]indazole 16 and imidazo[2,1-c]-1,2,4-triazine 19 derivatives, respectively upon refluxing in pyridine.

• Journal of Nutrition and Health
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• 제38권5호
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• pp.352-363
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• 2005

The previous extensive in vitro studies on the antioxidative activities of a number of Korean grains, vegetables, seaweeds and mushrooms, and the various combinations of these food source exhibited a wide range of antioxidative activities, and four food mixtures composed of 5 kinds of foods (5A, 5B, 5C and 5D) were designed from 16 selective foods showing. high antioxidant effect, in vitro, to find the good combinations for the meal planning. Mixture 5B or 5C contained very high levels of total flavonoid and polyphenol, and ethanol extract from 5A, 5B or 5C showed very strong inhibitory effects against in vitro $Fe^{2+}-induced$ lipid peroxidation and ethanol extract from 5B or 5C showed remarkable DPPH radical scavenging effect and lipid peroxide-protein conjugation inhibition effect. And in vivo study was also carried out with two mixtures (5B, 5C). Powders (P5B, P5C) or ethanol extracts (E5B, E5C) of these mixtures were supplemented to Sprague-Dawley rats fed on high fat $(15\%)-high$ cholesterol $(1\%)$ semipurified diet for 5 weeks. The total antioxidant power in serum was significantly higher in P5B, P5C, E5B and E5C groups than in high fat control group, and $ascorbate-Fe^{2+}-induced$ TBARS was significantly lowered by E5B supplementation in rat liver. In liver tissue, Cu, Zn-SOD activity was significantly higher in P5B and E5B groups than in high fat control group, while catalase or GSH-peroxidase (GPx) activity was not changed by any supplementations. In kidney, Cu, Zn­SOD activity was significantly higher in P5B group than in high fat control group, while GPx activity was not changed by any supplementations. Taken together, mixture 5B and 5C showed very strong antioxidative effects both in vitro and in vivo. Therefore, the ingredient Korean foods of 5B and 5C could be recommended to take a lot together for prevention from age-related chronic diseases.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2325-2329
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• 2013

Second-order rate constants $k_N$ have been measured for reactions of benzyl 2-pyridyl thionocarbonate (4b) and t-butyl 2-pyridyl thionocarbonate (5b) with a series of cyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. The $k_N$ values for the reactions of 4b and 5b have been compared with those reported previously for the corresponding reactions of benzyl 2-pyridyl carbonate (4a) and t-butyl 2-pyridyl carbonate (5a) to investigate the effect of changing the electrophilic center from C=O to C=S on reactivity and reaction mechanism. The thiono compound 4b is more reactive than its oxygen analogue 4a. The Br${\o}$nsted-type plots for the reactions of 4a and 4b are linear with ${\beta}_{nuc}=0.57$ and 0.37, respectively. The reactions of 4a were previously reported to proceed through a concerted mechanism, while those of 4b in this study have been concluded to proceed through a stepwise mechanism with formation of an intermediate being the rate-determining step on the basis of the ${\beta}_{nuc}$ value of 0.37. Enhanced polarizability upon changing the C=O in 4a by C=S has been suggested to be responsible for the reactivity order and the contrasting reaction mechanisms. In contrast, the reactivity of 5a and 5b is similar, but they are much less reactive than 4a and 4b. Furthermore, the reactions of 5a and 5b have been concluded to proceed through the same mechanism (i.e., a concerted mechanism) on the basis of linear Bronsted-type plots with ${\beta}_{nuc}=0.45$ or 0.47. It has been concluded that the strong steric hindrance exerted by the t-Bu in 5a and 5b causes a decrease in their reactivity and forces the reactions to proceed through a concerted mechanism.

• 한국식품조리과학회지
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• 제9권4호
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• pp.323-328
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• 1993

유지를 가열할때 생성되는 B(a)P 및 기타 PAHs함량과 각 유지의 이화학적 성질변화와의 관계를 비교해 봄으로써 각 유지의 적절한 가열 온도와 시간을 알아보기 위하여 시판 대두유를 $180\pm$5^{\circ}C$$,$200\pm$5^{\circ}C$$, $300\pm$5^{\circ}C$$,에서 50시간 가열한 것을 시료로 취하였다. 이들 각 시료의 B(a)P 및 기타 PAHs함량은 HPLC/UV를 사용하여 측정하였고, 산패와 관련된 이화학적 성질변화를 알아보기 위하여 가열유지의 산값(Acid Value, AV)과, 공액이중 산값(Conjugated Diene Value, CDNV)을 측정하였다. 그 결과는 다음과 같았다. 1. 시료로 사용한 대두유의 B(a)P 및 PAHs함량은 Pyr 1.093, B(a)P 0.986, Ch 1.147, DMBA 1.082, B(e)P 0.664, Per 1.135, B(a)P 0.146, DBA 1.053, 3-MC 0.055 $\mu\textrm{g}$/kg 이었다. 대두유를 $180\pm$5^{\circ}C$$, 에서 10,20,30,50시간 가열했을 때 B(a)P함량은 각각 0.391, 0.692, 0.451, 0.372$\mu\textrm{g}$/kg이었으며 $200\pm$5^{\circ}C$$, 와 $300\pm$5^{\circ}C$$,에서 가열했을 때 B(a)P함량은 각각 10시간일때 0.844와 0.466, 20시간일때 0.512와 0.706, 30시간일때 0.479와 0.607, 50시간일때 0.367과 0.247 $\mu\textrm{g}$/kg이었다. 2. 대두유를 10,20,30,50시 간 가열했을 때 산값은 180$\pm$5$^{\circ}C200\pm$5^{\circ}C$$,에서는 0.26, 0.26, 0.27, 0.33이었고, 200$\pm$5$^{\circ}C$에서는 0.23, 0.21, 0.21, 0.52였으며 $300\pm$5^{\circ}C$$,에서는 0.47, 1.57, 3.90, 6.42였다. CDNV는 $180\pm$5^{\circ}C$$,에서는 0.67,0.76,0.99,1.04였으며, $200\pm$5^{\circ}C$$,$^{\circ}C$에서는 0.39, 0.49, 3.27, 3.89였고 $300\pm$5^{\circ}C$$,에서는 0.65, 2.I5, 3.00, 3.88이었다. 3. 대두유를 가열했을 때 B(a)P의 생성과 산패도의 변화와의 관계를 볼때 B(a)P함량은 $180^{\circ}C$에서는 20시간가열시 0.692$\mu\textrm{g}$/kg, $200\pm$5^{\circ}C$$,에서는 10시 간 가열시 0.844$\mu\textrm{g}$/kg, $300\pm$5^{\circ}C$$,에서는 20시간 가열시 0.706$\mu\textrm{g}$/kg으로 가장 높게 생성된 후 서서히 감소하였다. 그러나 산값과 공액이중산값은 계속 증가하는 양상을 나타냈다. 즉 B(a)P생성과 산패도 변화사이에는 일정한 관계를 나타내지는 않았다.

• 한국동물학회지
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• 제34권2호
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• pp.228-231
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• 1991

한국인 383명의 Compiement Component 6(C6)의 유전적 다형을 등전점 전기영동과 immunoblotting으로 조사하였다. 5가지 allotypes, C6 A, C6 B, C6 B2, C6 Ml, C6 M11이 나타났고, 이들의 대립유전인자 빈도는 C6*A=0.4399, C6*B=0.5144, C6*B2=0.0392로 산출되어 이는 동아시아인과 비슷하였다.

• 한국세라믹학회지
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• 제40권3호
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• pp.279-285
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• 2003

Sol-gel 법으로 200 nm 정도의 두께를 가진 강유전성 S $r_{0.9}$B $i_{2.1}$T $a_{1.8}$ N $b_{0.2}$ 박막을 Pt/Ti $O_2$/ $SiO_2$/Si 기판 위에 증착하였다. 본 실험에서는 Sr(O $C_2$ $H_{5}$)$_2$, Bi(TMHD)$_3$, Ta(O $C_2$ $H_{5}$)$_{5}$ 그리고, Nb(O $C_2$ $H_{5}$)$_{5}$를 출발 물질로 사용하였으며 2-methoxyethanol을 용매로 사용하였다. UV 노광과 급속열처리가 SBTN 박막의 구조와 전기적 특성에 어떤 영향을 주는 가를 연구하였다. UV 노광과 급속열처리를 한 후에 $650^{\circ}C$ 열처리한 SBTN 박막의 3V와 5V 인가 전압하에서의 잔류분극 값은 각각 8.49와 11.94 $\mu$C/$ extrm{cm}^2$이었다.

• 한국결정학회지
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• 제6권1호
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• pp.36-42
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• 1995

상기제목의 화합물의 두가지 단결정이 n-hexane/CH2C12 과 n-hexane/Et2O 의 용매에 의하여 얻어졌으며, 그들의 서로 다른 공간군에도 불구하고 그들의 분자구조는 동일함이 밝혀졌다. C22H18N2O2 (I), Mr=343.70, Monoclinic, Pa, a=14.595(2), b=5.413(2), c=12.218(2)Å, β=96.86(1)°, V=958.3Å3, Z=2, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=292K, 756 유일한 반사강도에 대하여 R=0.104이다. 한 비대칭단위는 분자간의 두 개의 N-H…O 수소결합으로 연결된 dimer이다. C11H9NO (II), Mr=171.85, Monoclinic, P21/a, a=14.611(2), b=5.423(6), c=12.191(2)Å, β=96.89(1)°, V=959.0Å3, Z=4, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=293K, 824 개의 유일한 반사강도에 대한 R=0.066이다. 한 분자가 비대칭단위를 이루고 있으며 대칭중심관계에 있는 두 개의 N-H…O 수소결합으로 dimer 를 형성한다. 양쪽 구조에서 공히 선형인 diyne chain에 의하여 연결된 pyridyl 고리와 C(10)-C(11)-O가 만드는 평면간의 이면각은 수직에 가까우며, 그 분자들은 b-축을 반복주기로하여 b-축을 따라 쌓여있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1420-1421
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• 2006

In this study, structural and micowave dielectric properties of the $Mg_{5}B_{4}O_{15}$ (B=Ta, Nb) cation-deficient perovskite ceeramics. The specimens are prepared through the solid-state route. According to the XRD pattern, $Mg_{4}Ta_{2}O_9$ and $MgTa_{2}O_6$ phase exist in calcined and sintered $Mg_{5}Ta_{4}O_{15}$ powder. Also $Mg_{5}Ta_{4}O_{15}$ phase added with increasing sintering temperature. In the case of calcined and sintered $Mg_{5}Nb_{4}O_{15}$ powder, single phase of $Mg_{5}Nb_{4}O_{15}$ were appeared. The bulk density and quality factor of the $Mg_{5}B_{4}O_{15}$ (B=Ta, Nb) ceramics were increased with sinteming temperature in $1400^{\circ}C{\sim}1450^{\circ}C$, but these were decreased in another sintering temperature. Dielectric constant of the $Mg_{5}Ta_{4}O_{15}$ ceramics was increased continuously with increasing of sintering temperature. And the dielectric constant of the $Mg_{5}Nb_{4}O_{15}$ ceramics was increased in $1400^{\circ}C{\sim}1450^{\circ}C$ but decreased in $1475^{\circ}C$. In the case of the $Mg_{5}Ta_{4}O_{15}$ and $Mg_{5}Nb_{4}O_{15}$ ceramics sintered at $1450^{\circ}C$ for 5h, the dielectric constant, quality factor, and temperature coefficient of the resonant frequency (TCRF) were 8.2, 259,473 GHz, -10.91 $ppm/^{\circ}C$ and 14, 37,350 GHz, -52.3 $ppm/^{\circ}C$, respectively.

• 마이크로전자및패키징학회지
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• 제6권4호
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• pp.55-59
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• 1999

전자 패키징에 적용 가능한 납성분이 포함되어 있지 않는 Bi계저융점유리의 연구를 행하였다. Bi계유리중, 70wt% $Bi_2O_3$+ l5wt% $B_2O_3$ + 8wt% $SiO_2$+ 2wt% $P_2O_5$ + 4wt% $A1_2O_3$ + lwt%ZnO 성분의 유리는 융점이 약 $550^{\circ}C$ 였으며, $P_2O_5$의 함량에 따라서 그 융점이 변화하였다. 10wt%이상의 $P_2O_5$ 첨가에서는 $450^{\circ}C$의 열처리로 결정화가 진행되었다. $B_2O_3$가 많이 함유된 조성의 유리에서는 그 융점이 상승하였다.

• 한국세라믹학회지
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• 제55권5호
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• pp.440-445
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• 2018

To control the electrical properties of a SiC heating element, we sintered $SiC-ZrB_2$composites by using the spark plasma sintering method. The addition of $ZrB_2$ particles with lower electrical conductivity to the SiC matrices with comparatively higher electrical resistivity lowers the electrical resistivities of the composite material. The $ZrB_2$ particles aggregate to form large particles and 3-1, 3-2, and 3-3 networks, i.e., conduction paths. In our study, about $1-{\mu}m$-sized $ZrB_2$ powders start to form the conduction path at about 10 vol.% of addition, namely the threshold volume. The Joule heating experiment shows that 20 vol.% $ZrB_2$-added SiC heating element has outstanding heating efficiency.