• 센서학회지
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• 제12권6호
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• pp.265-272
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• 2003

본 논문은 파이렉스 #7740 유리 박막을 이용한 MEMS용 MLCA (Multi Layer Ceramic Actuator)와 Si기판의 양극접합 특성에 관한 것이다. 최적의 RF 마그네트론 스피터링 조건 (Ar 100%, input power $1\;W/cm^2$)하에서 MLCA기판위에 파이렉스 #7740 유리의 특성을 갖는 박막을 증착하였다. $450^{\circ}C$에서 1시간 열처리한 다음, -760 mmHg, 600V 그리고 $400^{\circ}C$에서 1시간동안 양극접합했다. 그 다음에 Si 다이어프램을 제조한 후, MLCA/Si 접합계면과 MLCA 구동을 통한 Si 다이어프램 변위특성을 분석 및 평가하였다. 다이어프램 형상에 따라 정밀한 변위 세어가 가능했으며 0.05-0.08 %FS의 우수한 선형성을 나타내었다. 또한, 측정동안 접합계면 균열이나 계면분리가 일어나지 않았다. 따라서, MLCA/Si기판 양각접합기술은 고성능 압전 MEMS 소자 제작공정에 유용하게 사용가능할 것이다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.182-182
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• 1999

The chemisorption effect of CO on the Ni/Cu(001) surface was investigated using LEED(Low Energy Electron Diffraction) and EELS(Electron Energy Loss Spectrscopy0 under the UHV conditions. after mounting the Cu(001) single crystal in the UHV chamber (base pressure 1$\times$10-10Torr), a clean surface was obtained after a few cycles of repeated Ar+ ion sputtering and annealing at about 40$0^{\circ}C$. The epitaxial thin Ni films were formed on the Cu(001) by evaporation from 99.999% Ni block. The pseudomorphic growth and the orderness of the thin Ni films were monitored by c(2$^{\circ}C$2) LEED pattern. CO adlayers on Ni epitaxial thin films were prepared by dosing pure CO has through a leak valve. After CO adsorpton at room temperature, two pairs of peaks were observed by EELS, whose relative intensities are changed as the film thickness is varied and time is elapsed. These two pair of peaks are likely related to different bonding sites (-top and bridge sites) of C-Ni as well as C-O vibration. Experimental results and qualitative interpretation of the spectra wille be discussed. The possibility of using EELS in combination with probe species (CO) to investigate the nature of thin film growth is mentioned. We will report the experimental result of O2 dosage on Ni film and interaction of CO and O2.

• 한국세라믹학회지
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• 제42권2호
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• pp.123-126
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• 2005

용매열법으로 출발물질의 농도를 변수로 차여 $BaTiO_3$ 분말을 합성하였다. 평균입자크기는 출발물질의 농도에 따라 비례하였는데 TiO_2를 기준으로 1/16M 농도에tj 59nm이었고 1/2M 농도에서는 89nm까지 증가하였다. 평균입자 크기가 89nm인 BT 분말에 대하여 리트벨트법에 의하여 분석한 결과 상분율은 정방정상 $75.5\%$이었고, 격자상수는 정방정상은 a=0.3999(nm), c=0.40319(nm)이고, 입방정상은 a=0.4015(nm)이었다. 이 분말을 $500^{\circ}C$ 1시간 열처리 후 TEM분석을 한 결과, 분말 내부에 수산 이온들이 거의 존재하지 않음을 확인하였다.

• 대한전자공학회논문지SD
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• 제37권1호
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• pp.36-43
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• 2000

청색 발광 SrS:CuCl TFEL 소자의 휘도를 향상시키기 위하여 황 압력과 열처리 조건을 최적화하여 SrS:CuCl TFEL 소자를 제작하였다. 전자빔 증착 장비를 이용하여 SrS:CuCl 형광체를 6000 ~ 8000 ${\AA}$ 두께로 증착 시킨 후, 800 $^{\circ}C$에서 3분 동안 열처리하여 TFEL 소자를 제작시켰다. 형광체 결정은 열처리 온도 및 열처리 지속 시간의 증가에 따라 향상되었다. SrS:CuCl TFEL 소자는 468 nm 와 500 nm에서 발광 피크 파장을 나타내었고, CIE 색 좌표는 x = 0.21, y = 0.33로 청색 빛이 방출되었다. SrS:CuCl TFEL 소자의 휘도$(L_{40})$는 형광체 증착 중의 황 압력에 크게 의존하여 황 압력을 $8{\times}10^{-6}$ torr에서 $2{\tiems}10^{-5}$ torr로 증가시켰을 때 262 cd/$m^2$에서 728 cd/$m^2$로 증가되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.458.2-458.2
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• 2014

We have demonstrated that simple brush-painted Ti-doped $In_2O_3$(TIO) films can be used as a cost effective transparent anodes for organic solar cells (OSCs). We examined the RTA effects on the electrical, optical, and structural properties of the brush painted TIO electrodes. By the direct brushing of TIO nanoparticle ink and rapid thermal annealing (RTA), we can simply obtain TIO electrodes with a low sheet resistance of 28.25 Ohm/square and a high optical transmittance of 85.48% under atmospheric ambient conditions. Furthermore, improvements in the connectivity of the TIO nano-particles in the top region during the RTA process play an important role in reducing the resistivity of the brush-painted TIO anode. In particular, the brush painted TIO films showed a much higher mobility ($33.4cm^2/V-s$) than that of previously reported solution-process transparent oxide films ($1{\sim}5cm^2/V-s$) due to the effects of the Ti dopant with higher Lewis acid strength (3.06) and the reduced contact resistance of TIO nanoparticles. The OSCs fabricated on the brush-painted TIO films exhibited cell-performance with an open circuit voltage (Voc) of 0.61 V, shot circuit current (Jsc) of $7.90mA/cm^2$, fill factor (FF) of 61%, and power conversion efficiency (PCE) of 2.94%. This indicates that brush-painted TIO film is a promising cost-effective transparent electrode for printing-based OSCs with its simple process and high performance.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권4호
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• pp.221-225
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• 1999

This paper shows the parameters to affect the critical characteristic of YBaCuO superconducting bulk fabricated by MPMG (Melt Powdered Melt Growth)process. In order to investigate proper processing variables, the effect of the holding time at the melting temperature and that of the slow cooling time in $O_2\; ambient\; on\; the\; J_c$ were experimented. And then with the above obtained heat treatment conditions, the effects of addition of $Y_2BaCuO_5\; and\; Ag\; on\; the\; J_c$ were also investigated. A proper slow cooling time yields phase transformation from Tetragonal $(YBa_2Cu_3O_6)$ to Orthorhombic $(YBa_2Cu_3O_7)$ during an annealing time in $O_2$. Ag addition plays a role in increasing the $T_c\; and\; the J_c$, but the magnetization decreases. The $J_c$ and the magnetization increase with addition of Y211. $J_c$ of the sample added Ag 10wt% is superiorover 3000 G. Proper holding time, slow cooling time and amount of impurity addition are important parameters in fabricating the YBaCuO bulk by MPMG process with high $J_c$.

• 대한기계학회논문집
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• 제10권6호
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• pp.807-813
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• 1986

본 연구에서는 국내에서 생산되고 있는 구상흑연주철을 이단으로 어니일링하 여 기타조직을 3가지(p$_{1}$:28.88% 페라이트, 63.5% 퍼얼라이트, p$_{2}$:49.7% 페 라이트, 42.2% 퍼얼라이트, p$_{3}$:71.26% 페라이트, 22.3% 퍼얼라이트)로 변화시켜 족삭에서 이차원절삭실험을 실시하여 기타조직에 따라 제절삭성(절삭력, 절삭비, 전단 각 및 침의 흐름속도)을 비교검토 하므로서 어니일링효과가 절삭성에 미치는 영향을 검토 연구하였다.

• 한국분말재료학회지
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• 제23권2호
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• pp.108-111
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• 2016

$Y_2O_3-H_3BO_3:Eu^{3+}$ powders are synthesized using a mechanical alloying method, and their photoluminescence (PL) properties are investigated through luminescence spectrophotometry. For samples milled for 300 min, some $Y_2O_3$ peaks ([222], [440], and [622]) and amorphous formations are observed. The 300-min-milled mixture annealed at $800^{\circ}C$ for 1 h with Eu = 8 mol% has the strongest PL intensity at every temperature increase of $100^{\circ}C$ (increasing from 700 to $1200^{\circ}C$ in $100^{\circ}C$ increments). PL peaks of the powder mixture, as excited by a xenon discharge lamp (20 kW) at 240 nm, are detected at approximately 592 nm (orange light, $^5D_o{\rightarrow}^7F_1$), 613 nm, 628 nm (red light, $^5D_o{\rightarrow}^7F_2$), and 650 nm. The PL intensity of powder mixtures milled for 120 min is generally lower than that of powder mixtures milled for 300 min under the same conditions. PL peaks due to $YBO_3$ and $Y_2O_3$ are observed for 300-min-milled $Y_2O_3-H_3BO_3$ with Eu = 8 mol% after annealing at $800^{\circ}C$ for 1 h.

• KSBB Journal
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• 제32권1호
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• pp.71-82
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• 2017

To verify anti-diabetic effect of oligopeptide with His-Pro repeats (mHP peptide), the oligopeptide was first secreted and optimized using the secretion vector, pRBAS with alkaline protease gene promoter and the signal sequence in Bacillus subtilis and directly the anti-diabetic effect of the mHP peptide was investigated in insulinoma cell, RINm5F cell line. The oligopeptide gene was obtained by annealing oligonucleotides with repeated His-Pro sequence and finally was constructed as 18 dipeptides (108 bp and 4.0 kDa) coding gene, named oligopeptide with His-Pro repeats (mHP peptide) to make cyclo(His-Pro) known to be anti-diabetic effects. The region encoding the oligopeptide gene was subcloned into the pRBAS secretion vector (E.coli-Bacillus shuttle vector) after PCR amplification using the designed primers including initiation and termination codons and His tag, named pRBAS-mHP (6.56 kb). To optimize secretion of the oligopeptide, various culture conditions were investigated in Bacillus subtilis LKS. As a result, the secreted oligopeptide was maximally measured (approximately $59.6{\mu}g/mL$) in 3 L batch culture and the highest secretion was achieved at $30^{\circ}C$, PY medium, and carbon sources (particularly barley and glycerol). In the RINm5F cells treated with 2 mM STZ, the oligopeptide treatment (0.1 mg/mL) restored the cell viability (10%) and reduced the nitric oxide (NO) generation (35%) and DNA fragmentation (90%). And also, insulin secretion level was increased to 17% higher than in STZ-treated RINm5F cells. These results suggest that the oligopeptide with His-Pro repeats could be a candidate material for anti-diabetic agent against STZ-induced diabetes.

• 한국재료학회지
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• 제19권5호
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• pp.253-258
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• 2009

Mn-substituted $BiFeO_3$(BFO) thin films were prepared by r.f. magnetron sputtering under an Ar/$O_2$ mixture of various deposition pressures at room temperature. The effects of the deposition pressure and annealing temperature on the crystallization and electrical properties of BFO films were investigated. X-ray diffraction patterns revealed that BFO films were crystallized for films annealed above $500^{\circ}C$. BFO films annealed at $550^{\circ}C$ for 5 min in $N_2$ atmosphere exhibited the crystallized perovskite phase. The (Fe+Mn)/Bi ratio decreased with an increase in the deposition pressure due to the difference of sputtering yield. The grain size and surface roughness of films increased with an increase in the deposition pressure. The dielectric constant of BFO films prepared at various conditions shows $127{\sim}187$ at 1 kHz. The leakage current density of BFO films annealed at $500^{\circ}C$ was approximately two orders of magnitude lower than that of $550^{\circ}C$. The leakage current density of the BFO films deposited at $10{\sim}30\;m$ Torr was about $5{\times}10^{-6}{\sim}3{\times}10^{-2}A/cm^2$ at 100 kV/cm. Due to the high leakage current, saturated P-E curves were not obtained in BFO films. BFO film annealed at $500^{\circ}C$ exhibited remnant polarization(2Pr) of $26.4{\mu}C/cm^2$ at 470 kV/cm.