RF sputtering을 이용한 BaTiO_3 세라믹 박막의 제조 및 특성에 관한 연구

이영희,류기원 광운대학교 신기술연구소 1997 신기술연구소논문집 Vol.26 No.-

본 연구에서는 RF sputtering을 이용하여 Pt/SiO_2/Si(100) 기판 위에 BaTiO_3 박막을 제조하였으며, 박막의 구조적, 결정학적 특성을 증착조건과 열처리온도에 따라 조사하였다. 최적의 Ar/O_2 gas 비, sputtering 압력, RF power, 그리고 열처리온도는 각각 4/1, 12[mTorr], 120[W] 그리고, 650℃ 1시간이었다. 이때 박막의 증착율은 0.75[Å/sec]였다. X선 회절분석의 결과로부터 최적조건에서 증착된 BaTiO_3 박막은 강유전상을 나타내었으며 유전상수와 유전손실은 각각 683, 0.05였다. In this paper, BaTiO_3 thin film on Pt/SiO_2/Si(100) substrates were prepared by RF sputtering, whose structural, crystallographic properties were examined according to the deposition conditions and annealing temperatures. The optimum Ar/O_2 gas flow rate, sputtering pressure, RF power and annealing temperature were 4/1, 12[mTorr], 120[W] and 650[℃] for 1[hr], respectively. The growth rate of deposition film was about 0.75[A /sec]. From the results of X-ray diffraction pattern, BaTiO_3 thin film deposited at the optimum conditions was a ferroelectric phase. The dielectric constant and loss were about 683 and 0.05, respectively.

PLZT 전자광학소자의 투광도 개선에 관한 연구

이영희 光云大學校 1987 論文集 Vol.16 No.-

In this study, PLZT cermics were fabricated by CP(Chemical-Preparation) and O₂ gas atomosphere method. According to the Pb₁?? formula, the composition rate of specimen was x=0.08, y=0.35 in memory region. The sintering temperature and time were varied from 1200[℃] to 1250[℃], from 30[hr] to 70[hr], respectively. The best optimal sintering conditions were investigated as a function of the electrical properties, the sintering density and the optical transmittane. As the result of the experiment, the specimens fabricated by flowing O₂ gas represented the better characteristics than the specimen fabricated by non-flowing O₂gas. The S-9 specimen, sintered at 1250[℃] for 60[hr], showed the most excellent optical transmittance(43%), the sintered density (7.421g/cm³) and the fundamental absorption edge(370nm). The dielectric constant of the specimen which sintered at 1250[℃] for 60[hr] was 4229, Curie point was 110[℃] and electro-mechanical coupling factor was 0.9. The remanent polarization of the specimen which sintered at 1250[℃] for 60[hr] was 30.3[μC/㎠], the coercive field was 8.64[KV], the remanent polarization and coercive field decreased with increasing of the temperature.

Channel stamping 법으로 전이된 Cu pattern의 형상

이영훈,곽재찬,강봉석,김희철,최병호,Lange, F.F. 國立金烏工科大學校 産業技術開發硏究院 2002 産業技術開發硏究 Vol.18 No.-

A matallo-organic solution was stamped from the channels of a polymer stamp onto a glass. The precursor solution consisted of copper 2-ethylhexanonate, 2-ethoxyethanol as a solvent and ethylene glycol to improve surface energies. The solution was deposited to the polymer stamp by spin coater. After drying the solution in channels of the stamp, the dried ink was transferred to a substrate by debonding from channels. The process parameters such as solution compositions and pressing methods were discussed experimentally to form a copper pattern whose morphology was excellent.

大黃水渡液이 물김치의 酸度變化에 미치는 影響

金英嬉,李正秀,蘇三燮,陳甲德 嶺南大學校 環境問題硏究所 1989 環境硏究 Vol.8 No.2

Effect of water and ethanol extract of Rheum coreanum N. on changes of pH in different NaC1 concentration and temperature in Juicy Kimchi was investigated and then, compared with it to sodium benzoate. The following results were obtained. 1. Addition of 0.03% water and ethanol extract of Rheum coreanum N. to juicy Kimchi preserved above pH 4.0 in whole experimental period at 30℃. 2. Addition of 0.1% water extract of Rheum coreanum N. induced less pH changes than control and preserved above pH 4.5 after 7 day at 18℃. 3. It was observed that water estract of Rheum coreanum N. was greater than ethanol extract in preservative potency. 4. Preservative potency of 0.03% water extract of Rheum coreanum N. was superior to 0.1% sodium benzoate. 5. Addition of 0.03% water extract of Rheum coreanum N. prolonged the tasty period of juicy Kimchi, which was more effective than sodium benzoate.

쌀 調理過程 中 麥飯石의 Cd除去 能力에 關한 硏究

陳甲德,裵基哲,李正秀,金英姬 嶺南大學校 環境問題硏究所 1989 環境硏究 Vol.9 No.1

It was investigated Cadmium eliminating capacty of Quartz Porphyry(Q.P.) during washing, swelling, and cooking process in rice contaminated artificially. 1. After washing the rice four times with water, the eliminating rate of Cadmium from artificially contaminated sample were 16% in control group, 28% and 42% in 25g/kg and 50g/kg Q.P. treated group, respectively. 2. Swelling of rice in water about 20 minutes didn't change the Cadmium level in Q.P. treated group. 3. Cadmium eliminating efficiency by cooking was significantly increased in Q.P. treated group (43~54%) compared to control group(31%). 4. These results suggest that treatment of rice with Q.P. is very effective to remove the Cadmium contamination in rice.

Cetyl Alchol을 利用한 坐制基劑에 關한 硏究

陳甲德,金英姬,李壽根,白琇鉉,李神雄 嶺南大學校 環境問題硏究所 1986 環境硏究 Vol.6 No.1

Some basic propeties of suppository bases containing cetyl alcohol(C), lanoline(L), and propylene glycol(P) were investigated in this study. The results were as follows. 1. Suppository could be molded easily in the higher amount of cetyl alcohol than that of lanoline or propylene glycol. 2. Suppository was molded by 28 kinds of different C:L:P ration could be soften in rectum temperature and the proper ratios of C:L:P to release sodium salicylate from suppository were 5:3:1, 3:1:2, 4:3:1, 5:3:2. 3. The softening times of suppository with these ratios of C:L:P were 9 min to 20 min. 4. Softening temperature and time were not changed after storage for 1, 11, 38, 54 days at 20℃ or 4℃ 5. The most appropriate ratio of this base was 5:3:1 in sodium salicylate suppository.

염화수소(Hydrogen Chloride)와 관련성이 추정되는 직업성 천식 1례

임현술,유선희,김두희,이영현 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

염화수소(hydrogen chloride)는 분자식은 HCl이며 염산가스라고 불리기도 하며 강한 자극성 냄새가 나는 무색의 기체이다. 물에 녹아서 염산이 되며 공기 중에서 물에 녹기 쉬운 성질 때문에 연무 형태로 존재한다. 본 증례로 34세 남자로 타이어에 사용되는 철사를 제조하는 공장에 다니는 근로자로 간헐적으로 고농도의 염화수소에 폭로된 후 1년 8개월의 잠복기를 거친 후 기관지 천식이 발생한 예로 총 호산구수는 증가되어 있었으나 혈청 IgE는 정상 범위였다. 55가지 알레르기항원을 사용한 피부 단자검사에서 House dust, Hay dust, Mixed grain, Dermatophagoides farinae와 Dermatophagoides pterynyssinus에 양성 반응을 보였고, 유발검사에서는 양성 반응을 보였다. 직업성 여부를 파악하기 위해 작업장 내에서 8시간 동안 근무하면서 30분 내지 한시간 간격으로 폐기능검사를 시행한 결과 1초간 노력성 호기량(FEV1) 이 20%이상 감소하여 2시간 동안 지속되는 양성 반응을 관찰할 수 있었다. 본 증례는 외인성 천식 소질이 있으면서 작업장 내에서 고농도의 염산증기에 폭로되어 기관지 천식 발작이 되었는데, 작업장의 고농도의 염화수소가 기관지 천식의 기여요인 또는 악화요인으로 작용하였다고 생각한다. Occupational asthma is an importent occupation-related disease. We exprienced a case of asthma induced by high concentration of hydrogen chloride vapour. The prevalence rate of this asthma is unknown. The patient of the case complained of cough, sputum and dyspnea after exposure to hydrogen chloride. Serum IgE(IgE-PRIST) was normal range but total eosinophil count was elevated. FEV₁ was 73% of predicted value and expiratory wheezing sound was observed on whole lung field. FEV₂was decreased to 48.9% of baseline on 5 hours 30 minutes, respectively, after exposure of hydrogen chloride at workplace. On follow up examination, the patient complained of an intermittent dyspnea and cough.

Electrical properties of lead-free 0.98(Na _0.5 K _0.5 )NbO ₃ -0.02Ba(Zr _0.52 Ti _0.48 )O ₃ piezoelectric ceramics by optimizing sintering temperature

Lee, Seung-Hwan,Lee, Sung-Gap,Lee, Young-Hie Springer 2012 Nanoscale research letters Vol.7 No.1

<P>Lead-free 0.98(Na<SUB>0.5</SUB>K<SUB>0.5</SUB>)NbO<SUB>3</SUB>-0.02Ba(Zr<SUB>0.52</SUB>Ti<SUB>0.48</SUB>)O<SUB>3 </SUB>[0.98NKN-0.02BZT] ceramics were fabricated by the conventional mixed oxide method with sintering temperature at 1,080°C to 1,120°C. The results indicate that the sintering temperature obviously influences the structural and electrical properties of the sample. For the 0.98NKN-0.02BZT ceramics sintered at 1,080°C to 1,120°C, the bulk density increased with increasing sintering temperature and showed a maximum value at a sintering temperature of 1,090°C. The dielectric constant, piezoelectric constant [<I>d</I><SUB>33</SUB>], electromechanical coupling coefficient [<I>k</I><SUB>p</SUB>], and remnant polarization [<I>P</I><SUB>r</SUB>] increased with increasing sintering temperature, which might be related to the increase in the relative density. However, the samples would be deteriorated when they are sintered above the optimum temperature. High piezoelectric properties of <I>d</I><SUB>33 </SUB>= 217 pC/N, <I>k</I><SUB>p </SUB>= 41%, dielectric constant = 1,951, and ferroelectric properties of <I>P</I><SUB>r </SUB>= 10.3 μC/cm<SUP>2 </SUP>were obtained for the 0.98NKN-0.02BZT ceramics sintered at 1,090°C for 4 h.</P>

The Effect of Choline Acetyltransferase Genotype on Donepezil Treatment Response in Patients with Alzheimer’s Disease

Lee, Kang Uk,Lee, Jung Hie,Lee, Dong Young,Youn, Jong Chul,Kim, Jeong Lan,Moon, Seok Woo,Kim, Bong-Jo,Ryu, Seung-Ho,Kim, Moon Doo,Lee, Chang-Uk,Lee, Nam-Jin,Chang, Sung Man,Kim, Young Hoon,Kim, Do Hoo Korean College of Neuropsychopharmacology 2015 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.13 No.2

<P><B>Objective</B></P><P>We examined the difference in responses to donepezil between carriers and non-carriers of the A allele at the +4 position of the choline acetyltransferase (ChAT) gene in Koreans.</P><P><B>Methods</B></P><P>Patients who met the criteria for probable Alzheimer’s disease (AD) (n=199) were recruited. Among these, 145 completed the 12-week follow-up evaluation and 135 completed the 26-week scheduled course. Differences and changes in the Korean version of the mini-mental state examination (MMSE-KC) score, Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease Neuropsychological Assessment Battery (CERAD-K[N]) wordlist subtest score (WSS), CERAD-K(N) total score (TS), and the Korean version of geriatric depression scale (GDS-K) score between baseline and 12 weeks or 26 weeks were assessed by the Student’s <I>t</I>-test.</P><P><B>Results</B></P><P>At 12 weeks, the changes in the MMSE-KC score, CERAD-K(N) WSS, and CERAD-K(N) TS from baseline were not significant between ChAT A allele carriers and non-carriers; however, at 26 weeks, these changes were significantly larger in ChAT A allele carriers than in non-carriers (<I>p</I>=0.02 for MMSE-KC and <I>p</I>=0.03 for CERAD-K(N) WSS respectively).</P><P><B>Conclusion</B></P><P>Our findings in this study suggested that presence of the A allele at the +4 position of ChAT might positively influence the treatment effect of donepezil in the early stages of AD in Koreans.</P>

Piezoelectric Properties of ZnO-Doped 0.98(Na_0.5K_0.5)NbO₃-0.02Ba(Zr_0.52Ta_0.48)O₃ Ceramics

Lee, Seung-Hwan,Nam, Sung-Pill,Lee, Sung-Gap,Lee, Young-Hie Informa UK (Taylor Francis) 2012 Integrated ferroelectrics Vol.140 No.1