• 분석과학
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• 제26권1호
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• pp.80-85
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• 2013

본 연구는 유해화학물질관리법에 지정되어 있는 사고대비물질에 대한 실험실적 분석방법을 정립하기 위한 것으로, GC/MS 분석이 가능한 25종 사고대비물질을 대상으로 정량분석을 수행하였다. GC/MS 정량분석결과 69종 사고대비물질 중 산화프로필렌(propylene oxide) 등 21개 물질에 대한 결정계수($r^2$)는 0.998 이상을 보였고, 포스겐(phosgene)의 결정계수는 0.994, 노말-부틸아민(n-butyl amine) 외 1종은 0.987, 에틸렌디아민(ethylene diamine)은 0.958의 결정계수를 보였다. 동일한 GC/MS 분석 조건으로 표준물질을 분석한 결과 총 25종에 대한 검량선이 작성되었다. 현재 사고대비물질에 대한 분석 연구가 필요한 상황에서, 본 연구결과는 화학사고 사후 환경 영향 조사를 위한 정량분석에 도움이 될 것으로 판단된다.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.457-463
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• 2013

PURPOSE. The purpose of this study was to compare the effect of a diode laser and traditional irrigants on the bond strength of self-adhesive cement. MATERIALS AND METHODS. Fifty-five incisors extracted due to periodontal problems were used. All teeth were instrumented using a set of rotary root canal instruments. The post spaces were enlarged for a No.14 (diameter, 1.4 mm) Snowlight (Abrasive technology, OH, USA) glass fiber reinforced composite post with matching drill. The teeth were randomly divided into 5 experimental groups of 11 teeth each. The post spaces were treated with the followings: Group 1: 5 mL 0.9% physiological saline; Group 2: 5 mL 5.25% sodium hypochlorite; Group 3: 5 mL 17% ethylene diamine tetra acetic acid (EDTA), Group 4: 37% orthophosphoric acid and Group 5: Photodynamic diode laser irradiation for 1 minute after application of light-active dye solution. Snowlight posts were luted with self-adhesive resin cement. Each root was sectioned perpendicular to its long axis to create 1 mm thick specimens. The push-out bond strength test method was used to measure bond strength. One tooth from each group was processed for scanning electron microscopic analysis. RESULTS. Bond strength values were as follow: Group 1 = 4.15 MPa; Group 2 = 3.00 MPa; Group 3 = 4.45 MPa; Group 4 = 6.96 MPa; and Group 5 = 8.93 MPa. These values were analysed using one-way ANOVA and Tukey honestly significant difference test (P<.05). Significantly higher bond strength values were obtained with the diode laser and orthophosphoric acid (P<.05). There were no differences found between the other groups (P> .05). CONCLUSION. Orthophosphoric acid and EDTA were more effective methods for removing the smear layer than the diode laser. However, the diode laser and orthophosphoric acid were more effective at the cement dentin interface than the EDTA, Therefore, modifying the smear layer may be more effective when a self-adhesive system is used.

• 대한전자공학회논문지SD
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• 제37권6호
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• pp.17-23
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• 2000

본 연구에서는 Sq색소를 이용하여 적색발광의 디바이스를 제작하고, 발광효율을 증가시키기 위해 OXD7과 $Alq_3$층을 발광층과 음극사이에 삽입하여 그 효과를 관측하고, 기구특성을 검토하였다. 정공운송층으로서 TPD, 발광층 호스트재료로서 $Alq_3$, 게스트 재료로서 Sq를 사용하였다. 그 결과 $Alq_3$층의 삽입은 효율을 증가시킬 수 있었지만, 삽입된 $Alq_3$층에서의 발광 때문에 색순도 높은 적색발광을 얻지 못했다. OXD7층의 삽입은 정공을 블로킹하고 정공을 누적시킨다. 이는 전자와 정공의 재결합확률을 증가시키기 때문에 색순도 높은 적색발광을 유지하면서 휘도 특성과 발광효율이 향상되었다.

• 약학회지
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• 제38권4호
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• pp.440-450
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• 1994

Due to the limited bioavailability of $[D-Ala^6]$LHRH from nonparenteral transmucosal sites of administration, enhancement of mucosal permeability by coadministration of several protease inhibitors and/or penetration enhancers were studied in rabbit mucosa. As a reliable bioassay method for $[D-Ala^6]$LHRH, ovulation-inducing effect were measured after vaginal administration in the rat. The permeation of $[D-Ala^6]$LHRH through the mucosal membrane of rabbit mounted on George-Grass diffusion cells were examined in the presence of polyoxyethylene 9-lauryl ether (POE), ${\beta}$-cyclodextrin$({\beta}-CyD)$ or ethylene diamine tetra acetate disodium salt(EDTA). The vaginal membrane showed higher permeability of $[D-Ala^6]$LHRH than the rectal and nasal membrane. POE and ${\beta}-CyD$ showed a small promoting effect on the membrane permeation of $[D-Ala^6]$LHRH, but EDTA showed significant enhancement. Ovaluation was enhanced by the coadministration of sodium laurate(0.5%), a protease inhibitor but was not enhanced by EDTA, a penetration enhancer. On the other hands, coadministration of sodium tauro 24,25 dihydrofusidate(1%) and EDTA(2%) enhanced the ovulation inducing-effect 2.8 times. These results suggest that the vaginal administration of $[D-Ala^6]$LHRH with STDHF or sodium laurate as a protease inhibitor, and EDTA as a penetration enhancer, may become an elective method for transmucosal delivery of $[D-Ala^6]$ LHRH.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.238-243
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• 2014

합성된 스테인레스 스틸에 대한 NATM(New Austria Tunnel Method) 수지의 기계적 특성은 SEM, FT-IR, 인장특성, 그리고 [NCO]/[OH]의 mole %, 입도분석에 의해 측정하였다. 친환경적인 NATM에 관한 관심이 고조됨에 따라 스테인레스 등의 금속에 코팅하는 무용제 도료를 합성하였다. 폴리올, IPDI, 충진제, 실리콘 계면활성제, 촉매 등이 함유된 기존 NATM수지보다 폴리올, MDI, 충진제, 실리콘 계면활성제, 촉매, 가교제가 함유되어 합성된 NATM 수지의 도료가 내구력과 강도가 양호하였다. 견고한 NATM 수지의 기계적 특성은 가교와 [NCO]/[OH]의 mole%가 증가함에 따라 강도가 증가하였다. 결론적으로 NATM의 가교된 미세조직는 스테인레스 스틸 같은 금속물질 코팅에 좋은 물질이다.

• 멤브레인
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• 제18권1호
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• pp.94-102
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• 2008

염색폐수처리를 위하여 피페라진, 메타페닐렌디아미, 트리메소일 클로라이드를 이용하여 계면중합법으로 폴리아마이드계 나노분리막과 폴리아마이드계 역삼투막을 제조하였으며, 이들을 오스모닉스사로부터 구입한 역삼투막의 투과특성과 비교하였다. 이들의 기본 분리투과특성 조사를 위하여 PEG 600, $Na_2SO_4$, NaCl 수용액을 이용하였으며, 제조된 분리막들은 전형적인 나노복합막과 저압용 역삼투막의 특성을 나타내었다. 제조된 이들 분리막들을 이용하여 국내 염료 제조업체인 (주)경인양행으로부터 공급된 실제 염색폐수를 처리하였으며, 이때 이들의 분리투과특성을 살펴보았다. 또한 분리막을 이용한 폐수처리 시 발생되는 분리막 오염을 제거하기 위하여 일정시간마다 CIP를 실시하였다. 이때 3종류의 서로 다른 화학세정제를 사용하였으며, 이들의 세척성능을 살펴보았다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.254-254
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• 2011

The memories with nano-particles are very attractive because they are promising candidates for low operating voltage, long retention time and fast program/erase speed. In recent, various nano-floating gate memories with metal-oxide nanocrystals embedded in organic and inorganic layers have been reported. Because of the carrier generation in semiconductor, induced photon pulse enhanced the program/erase speed of memory device. We studied photo-induced electrical properties of these metal-oxide nanocrystal memory devices. At first, 2~10-nm-thick Sn and In metals were deposited by using thermal evaporation onto Si wafer including a channel with $n^+$ poly-Si source/drain in which the length and width are 10 ${\mu}m$ each. Then, a poly-amic-acid (PAA) was spin coated on the deposited Sn film. The PAA precursor used in this study was prepared by dissolving biphenyl-tetracarboxylic dianhydride-phenylene diamine (BPDA-PDA) commercial polyamic acid in N-methyl-2-pyrrolidon (NMP). Then the samples were cured at 400$^{\circ}C$ for 1 hour in N atmosphere after drying at 135$^{\circ}C$ for 30 min through rapid thermal annealing. The deposition of aluminum layer with thickness of 200 nm was followed by using a thermal evaporator, and then the gate electrode was defined by photolithography and etching. The electrical properties were measured at room temperature using an HP4156a precision semiconductor parameter analyzer and an Agilent 81101A pulse generator. Also, the optical pulse for the study on photo-induced electrical properties was applied by Xeon lamp light source and a monochromator system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.542-545
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• 2002

High performance organic electroluminescnet(EL) devices which are composed of organic thin multilayer films are fabricated. The basic structure is ITO/Emitting layer/LiF/Al in which have a blended emitting layer. The emitting layer is consisted of a host material(N,N' diphenyl-N,N' (3-methyl phenyl)-l,l'-biphenyl-4,4'diamine)(TPD)) and a guest emitting material(poly(3-hexylthiophehe)(P3HT)). We think that the energy transfer in blending layer occurred from TPD to P3HT. Red emitting multilayer EL devices were fabricated using tris(8-hydroxyqunolinate) aluminum$(Alq_3)$ as electron transport material. The device structure of ITO/blending layer(TPD+P3HT)$/Alq_3$/LiF/Al was employed. In the Voltage-current-luminance characteristics of multilayer device, the device tum on at the 2V and the luminance of $10{\mu}W/cm^2$ obtain at l0V. Red emission peak at 640nm was observed with this device structure. We have presented evidence that the excitation energy migration between a polymeric host and guest has to be explained. And by using multilayer, the red light emitting EL device enhances not only Voltage-current-luminance characteristic but also stability of device.

• Nuclear Engineering and Technology
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• 제28권1호
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• pp.44-55
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• 1996

원자력 발전소에서 방사성 요오드를 제거하기 위해 사용되는 원료활성탄과 2%, 5%TEDA(Triethylene-Diamine) 첨착활성탄을 이용하여 원소요오드와 유기요오드인 메틸요오드에 대한 흡착특성을 분석하였다. 여러 흡착 등온식을 선정하여 실험치와 비교함으로서 선정된 흡착 등온식의 적합성 여부를 검증하였다. 흡착평형 실험결과 Dubinin-Astakhov(DA) 등온식이 여러 가지 흡착등온식 가운데 가장 적합한 것으로 나타났다. 흡착표면의 흡착에너지 분포가 불균일(Heterogeneous)하기 때문에 포텐셜 (Potential) 에너지를 근거로 하는 DA등온식이 흡착평형 관계를 보다 정확하게 나타내는 것으로 생각된다. 흡착표면의 불균일성을 확인하기 위해 흡착에너지 분포도를 원료활성탄과 첨착활성탄에 대해 상호 비교하였다 활성탄-요오드 흡착시스템에서 불균일성은 활성탄의 기공구조 분만 아니라 흡착질과 활성탄과의 상호관계에 의해서도 영향을 받게된다 따라서 흡착표면의 불균일성은 활성탄을 첨착함에 따라서 증가하게 되고 원소요오드보다 유기요오드의 경우 불균일성이 더 커지는 것으로 보여진다.

• 반도체디스플레이기술학회지
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• 제15권2호
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• pp.38-42
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• 2016

We investigate the solution coating process of organic small molecules that are easily recrystallized in a solvent. The spin-coated films of small molecule N,N'-diphenly-N,N'-bis(1,1'-biphenyl)-4,4'-diamine (NPB) exhibit many aggregations on the surface and thus poor surface morphology. To tackle it, we have added a chain-entangled polymer poly(N-vinylcarbazole) (PVK) into the NPB solution. It is found that a small amount of PVK indeed prohibits the recrystallization of NPB in a solvent. By the addition of PVK (30 wt%), the peak-to-peak roughness of the films is reduced from 262 nm down to 2.7 nm, which is even lower than that (~5.1 nm) of the polymer film. It is also demonstrated that OLED with the PVK-mixed NPB film shows higher current and power efficiencies, compared to OLED with the NPB or PVK film. It is attributed that the addition of PVK into NPB suppresses the occurrence of leaky channels induced by the recrystallization phenomenon.