• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2003년도 추계학술발표회초록집
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• pp.119-119
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• 2003

Plasma polymerized organic thin films were deposited on Si(100) glass and Copper substrates at 25 ∼ 100 $^{\circ}C$ using cyclohexane and ethylcyclohexane precursors by PECVD method. In order to compare physical and electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 20∼50 W and deposition temperature on both corrosion protection efficiency and physical properties were studied. We found that the corrosion protection efficiency (P$\_$k/), which is one of the important factors for corrosion protection in the interlayer dielectrics of microelectronic devices application, was increased with increasing RF power. The highest P$\_$k/ value of plasma polymerized ethylcyclohexane film (92.1% at 50 W) was higher than that of the plasma polymerized cyclohexane film (85.26% at 50 W), indicating inhibition of oxygen reduction. Impedance analyzer was utilized for the determination of I-V curve for leakage current density and C-V for dielectric constants. To obtain C-V curve, we used a MIM structure of metal(Al)-insulator(plasma polymerized thin film)-metal(Pt) structure. Al as the electrode was evaporated on the ethylcyclohexane films that grew on Pt coated silicon substrates, and the dielectric constants of the as-grown films were then calculated from C-V data measured at 1㎒. From the electrical property measurements such as I-V ana C-V characteristics, the minimum dielectric constant and the best leakage current of ethylcyclohexane thin films were obtained to be about 3.11 and 5 ${\times}$ 10$\^$-12/ A/$\textrm{cm}^2$ and cyclohexane thin films were obtained to be about 2.3 and 8 ${\times}$ 10$\^$-12/ A/$\textrm{cm}^2$.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 가을 학술발표회논문집
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• pp.25-28
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• 1998

Since the first report on poly(p-phenylenevinylene), the electroluminescent properties of namy conjugated polymers such as poly(p-phenylenevinylene) (PPV), poythiophene (PT), poly(p-phenylene) (PPP), and polyfluorene (PF) have been investigated because of their potential for use in display technology However, in the application of polymer light-emitting diodes (PLEDs), there are yet three fundamental issues to be considered: (1) full color capability, (2) emission efficiency, (3) stability (lifetime). (omitted)

• 한국자원식물학회지
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• 제35권2호
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• pp.380-384
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• 2022

본 연구에서 PTS는 지방전구세포에서 PPARγ, C/EBPα 및 FABP4의 발현 억제를 통해 지방전구세포의 adipogenesis를 억제하고, AMPK 및 HSL의 활성화, ATGL의 발현증가, 그리고 perilipin-1의 발현감소를 통해 지방세포의 지질을 분해하여 지방세포 내 과도한 지질형성을 억제하는 것으로 판단된다. 이러한 결과들은 PTS는 비만 예방 및 치료를 위핸잠재적 식의약 소재로의 개발 및 활용이 가능할 것으로 사료된다.

• Korean Chemical Engineering Research
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• 제57권2호
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• pp.164-171
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• 2019

The protonation parameters, dissociation constants ($pK_{BH^+}$) of conjugate acid, slope values (m, ${\phi}$ and $m^*$) and correlation coefficients (r) of hydroxamic acids were determined by Hammett acidity function method, Bunnett-Olsen method and excess acidity method in hydrochloric and perchloric acid solutions. Effect of acid concentration on partition and percentage protonation was also studied. $pK_{BH^+}$ values show that hydroxamic acids do not behave as Hammett bases, but hydroxamic acids behave as weak bases in strong acidic solutions. The values of $pK_{BH^+}$ obtained through Bunnett-Olsen method and excess acidity method were compared with the Hammett acidity function. ChemAxon's MarvinSketch 6.1.5 software was also used for determining $pK_a$, pI and microspecies distribution (%) of hydroxamic acids with pH. Hydrogen donor and acceptor values and logD were also obtained. The results show that N-p-chlorophenyl-4-bromobenzohydroxamic acid has the highest $pK_a$ and lowest logD values. On the contrary, N-phenyl-3,5-dinitrobenzohydroxamic acid has lowest the $pK_a$ and highest logD values.

• 한국재료학회지
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• 제7권5호
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• pp.381-385
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• 1997

PEMOCVD에 의해서 SrBi$_{2}$Ta$_{2}$O$_{9}$밥막이 낮은 온도에서 성공적으로 Pt/Ti/SiO$_{2}$Si위에 증착되었다. 5$50^{\circ}C$에서 증착된 200nm박막은 치밀하고 작은 결정립을 보였으며 3V의 인가전압하에서 이력곡선은 포화되기 시작하였다. 3V에서 박막은 잔류분극 (P$_{r}$)과 항전계(E$_{c}$)는 각각 15$\mu$/$\textrm{cm}^2$과 50kV/cm이었다. 6V bipolar square pulse의 피로측정에서 박막은 1.0x$10^{11}$cycles까지 피로 현상을 보이지 않았다. PEMOCVD에 의해서 5$50^{\circ}C$에서 증착된 SBT박막은 비휘발성 기억소자에 충분히 활용할 수 있다.다.

• 정신신체의학
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• 제10권1호
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• pp.37-47
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• 2002

연구목적 : 수면관련 호흡장애 (sleep-related breathing disorder, SRBD)는 생명을 위협하는 중요한 질환으로 유병율이 매우 높다. 본 연구의 목적은 일차성 코골이 (PS) 환자와 폐쇄성 수면무호흡증 (OSA) 환자들이 보이는 정신의학적 증상들을 조사하는데 있다. 방법 : 동아대학교병원 수연장애 클리닉에 내원, SRBD가 의심되어 수면다원검사를 시행한 환자 중, SRBD로 확진받은 80명 (PS 29명 OSA 51 명)을 연구대상으로 하였다. 다면적 인성검사 (MMPI)와 간이정신진단검사 (SCL-90-R)를 실시하여 PS군과 OSA군의 정신의학적 증상들을 조사 분석하였다. 결과 : 전체 SRBD 환자군은 MMPI의 건강염려증(Hs), 우울증(D), 히스테리(Hy) 척도와 SCL-90-R의 선체화(SOM) 척도의 증가율이 타 척도보다 더 높았다. 이런 현상은 PS와 OSA로 구분하였을 때도 두군 모두에서 3가지 신경증 척도들의 증가율이 높았다 두군간의 비교에서, SCL-90-R의 강박증 (O-C, t=2.14), 우울증 (DEP, t=2.44), 편집증 (PAR, t=2.56), 전체 심도지수 (GSI, t=2.32) 척도(이상 p<0.05) 및 신체화(SOM, t=2.46), 표출 증상합계 (PST, t=2.75) 척도(이상 p<0.01)의 평균점수, 그리고 MMPI의 건강염려증(Hs, t=3.39) 척도와 SCL-90-R 신체화 (SOM, t=6.52) 척도의 증가율이 PS군보다 OSA군에서 유의하게 높았다(모두 p<0.05). 반응 척도와 수면 변인들 간의 상관관계 조사에서, 몇몇 심리 반응 척도들 즉, OSA군의 MMPI(D, Pt, Si) 및 SCL-90-R(ANX, PAR, PSDI) 척도와 PS군의 MMPI(Hy, Pt, Si) 및 SCL-90-R(I-S, PAR. PSDI) 척도, 그리고 PS군의 MMPI 척도 증가율(E')이 수면효율과 서파수면시간 등의 다양한 수면변인들과 상관관계를 보였다. 결론 : 본 연구의 결과는 SRBD 환자들이 신체화 경향을 주로 하는 신경증적 특정을 보이고 있음을 시사한다. 또한 비록 OSA군이 PS군에 비하여 정신의학적 증상을 더 심하게 호소하고 있지만, PS군도 일반인구보다 정신의학적 증상을 더 많이 호소하고 있었다. 이 결과는 OSA군뿐만 아니라 PS군에 대한 정신의학적 관심이 필요함을 시사한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.382.1-382.1
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• 2014

Graphene field-effect transistors (GFET) is one of candidates for future high speed electronic devices since graphene has unique electronic properties such as high Fermi velocity (vf=10^6 m/s) and carrier mobility ($15,000cm^2/V{\cdot}s$) [1]. Although the contact property between graphene and metals is a crucial element to design high performance electronic devices, it has not been clearly identified. Therefore, we need to understand characteristics of graphene/metal contact in the GFET. Recently, it is theoretically known that graphene on metal can be doped by presence of interface dipole layer induced by charge transfer [2]. It notes that doping type of graphene under metal is determined by difference of work function between graphene and metal. In this study, we present the GFET fabricated by contact metals having high work function (Pt, Ni) for p-doping and low work function (Ta, Cr) for n-doping. The results show that asymmetric conductance depends on work function of metal because the interfacial dipole is locally formed between metal electrodes and graphene. It induces p-n-p or n-p-n junction in the channel of the GFET when gate bias is applied. In addition, we confirm that charge transfer regions are differently affected by gate electric field along gate length.

• 생명과학회지
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• 제10권1호
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• pp.68-73
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• 2000

In order to develop new materials for the functional food, the components of safflower(Carthamus tinctorius L.) sprout was studied. Chemical composition, minerals, amino acids, and fatty acids of the leaf and the stem parts of 2 weeks grown safflower sprout were analyzed. The chemical composition of safflower spout was 12.7% (w/w) moisture, 28.5% crude protein, 10.1% crude fat, and 5.3% crude ash. Mineral contents of the leaf part were P 49%, K 22%, Mg 15%, Ca 10% whereas these of the stem part were K 51%, P 27%, S 10%, Ca 7%, Mg 4%. Other mineral contents were less than 2% in both parts. Especially, Pt was 0.18 ppb and 0.17 ppb in the leaf and the stem parts, respectively. The composition of the amino acid were approximately as follow, the major amino acid in the leaf and the stem were aspartic acid and glutamic acid, the contents of these were 10.7mg/g, 10mg/g in the leaf, 11.3 mg/g, 8.4 mg/g in the stem, respectively. The major fatty acids in the leaf and the stem parts were linoleic acid and $\alpha$-linolenic acid. The linoleic acid (C18:2) in the leaf and the stem parts were 67% (w/w) and 47% whereas the $\alpha$-linolenic acid. The linoleic acid (C18:2) in those parts were 14% (w/w) and 11%, respectively. On the basis of chemical analysis, the safflower sprout showed to have relatively high contents of crude protein and crude fat, minerals including small amount of Pt, polyunsaturated fatty acid as linoleic acid and $\alpha$ -linolenic acid. These results suggested that safflower sprout was found to be a useful material of natural health food for the functional food development.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2002년도 춘계학술발표논문집
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• pp.121-123
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• 2002

졸-겔법(Sol-Gel Method)으로 강유전체 Bi/sub 3.3/La/sub 0.7/Ti/sub 3/O/sub 12/(BLT) 박막을 Pt/Ti/SiO₂/Si 기판위에 스핀 코팅하여 Metal-Ferroelectric-Metal(MFM 구조를 형성하였다. As-coated BLT 박막은 650℃ 이상에서 결정화되었으며, 전형적인 Bi층상의 페롭스카이트 결정구조를 나타내었다. 또한 열처리 온도를 증가시킴에 따라 결정성이 향상되었다. 3V 전압에서 650℃로 열처리된 박막의 경우 누설전류가 약 2.25×10/sup -8/A/㎠ 정도를 보였다. 650℃에서 열처리된 BLT박막은 5V의 인가 전압에서 잔류분극 2Pr(±(P/sup */-P/sup A/)) 값은 약 29.5μC/㎠을 나타내었으며, 1.5×10/sup 10/ 스위칭 cycles까지 분극 스위칭을 반복한 후에도 거의 잔류 분극의 변화가 없었다.

• 한국진공학회지
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• 제5권3호
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• pp.245-250
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• 1996

$Y_2O_3$ thin film on si(100) was successfully grown by ionized cluster beam(ICBD) technique at substrate temperature of around $500^{\circ}C$ and pressure of ~$10^{-5}$Torr.To prevent the oxidation of Si substrae, a very thin yttrium layer was deposited on Si before reactive depositing of oxygen and yttrium source. In asdeposited stage, b.c.c and h.c.p strucutres of $Y_2O_3$ were observed from S-ary analysis. From the observation of spots and ring patterns in selected area diffractin(SAD) patterns. crystallane formation and growth could be proceeded during the deposition. $Y_2O_3$/mixed layer/$SiO_2=170\AA/50\AA/10\AA$ structure were verified by high resolution transmition electron imcroscopy(HRTEM) image, and the formation of amorphous layer of SiO2 was discussed . Electricla charateristics of the film were also investigated . In as-deposited Pt/$Y_2O_3$/Si sturcuture, leakage current was less than $10^{-6}$A/$\textrm{cm}^2$ at 7MV/cm strength.