• 치위생과학회지
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• 제17권6호
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• pp.481-486
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• 2017

본 연구는 OTC 미백술에서 사용되고 있는 2.9% 과산화수소 함유 젤과 과산화수소 함유 첩부제 제품을 광조사기와 각각 혼합 사용했을 때의 실험실 및 임상적 효과를 비교 평가하고자 하였다. 실험실적 평가는 변형된 Stookey's method를 이용하여 착색시킨 HAP 시편을 이용하여 20분간 각 실험제품을 적용하고 광을 조사하였다. 임상적 평가에서는 하루 15분씩 4일간 각 실험제품과 광조사를 진행하였고, Vita 색조편을 이용한 육안적 평가와 Shade eye-NCC를 이용한 기기적인 평가를 진행하였다. 실험실적 평가 결과 과산화수소 함유 첩부제와 광을 사용한 군이 과산화수소 함유 젤과 광을 사용한 군에 비해 색조 변화 값(${\Delta}E^*$)이 유의하게 높게 나타났다(p<0.001). 임상적 평가에서는 Vita 색조편을 이용한 육안평가 결과, 첩부제와 광을 사용한 군이 젤과 광을 사용한 군보다 제품 사용 전후 색조 변화 값이 좀 더 큰 경향을 나타내었으나 군간 유의차는 없었다(p>0.05). Shade eye-NCC를 이용한 기기적 평가 결과에서 ${\Delta}E^*$값은 첩부제와 광을 사용한 군이 젤과 광을 사용한 군보다 좀 더 높았으나 군간 유의차는 나타나지 않았고(p>0.05), ${\Delta}b^*$값은 첩부제와 광을 사용한 군이 유의하게 높게 나타났다(p=0.024). 본 연구에서는 광조사기와 혼합 사용하는 과산화수소 젤 또는 첩부제 형태의 물리적 성상에 따른 치아미백제품의 미백효과 평가 결과 첩부제 형태의 과산화수소 제제가 젤 형태보다 치아미백효과가 높은 것으로 나타났다.

• Current Photovoltaic Research
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• 제2권2호
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• pp.53-58
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• 2014

$Tb^{3+}$ - or $Ce^{3+}$-doped $LaBO_3$ phosphors were synthesized by a solid-state reaction process with different concentrations of activator ions. The XRD spectra showed the monoclinic $LaBO_3$ pattern with the main peak occurring at (014) plane, irrespective of the kind of activator ions. The crystallite size was determined by using the Scherrer formula, and the maximum was obtained with an activator concentration of 0.05 mol for both phosphors. The emission spectra of $LaBO_3$ phosphors doped with $Tb^{3+}$ ions under excitation at 269 nm exhibited three major emission bands at 488, 544, and 587 nm. The strongest emission was green at 544 nm owing to the $^5D_4-^7F_5$ transition at a $Tb^{3+}$ ion concentration of 0.05 mol. For the $Ce^{3+}$-doped $LaBO_3$ phosphors, one strong blue band centered at 469 nm and weak multipeaks were observed. These results suggest that the optimum green and blue emission can be realized by controlling the concentration and type of activator ions incorporated in the host crystal.

• Journal of Photoscience
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• 제9권2호
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• pp.86-89
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• 2002

Blue light activates proton pump, and creates electrical gradient across the plasma membrane and drives $K^{+}$ uptake in stomatal guard cells. In this presentation, we provide evidence for regulatory mechanisms of the pump and the identification of blue light receptor. The pump is shown to be the plasma membrane H$^{+}$- ATPase and is activated through phosphorylation of the C-terminus. Phosphorylation occurred and 14-3-3 protein bound to the phosphorylation site. The binding of 14-3-3 protein was required for the H$^{+}$-ATPase activation. We also found that phot1 phot2 double mutant does not respond to blue light but other mutants respond to blue light by stomatal opening. However, all these mutants are capable of stomatal opening in the presence of fusicoccin, an activator of the H$^{+}$-ATPase. These results suggest that both photl and phot2 act as blue light receptors in guard cells.d cells.

• Journal of Korean Neurosurgical Society
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• 제37권4호
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• pp.287-292
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• 2005

Objective: Recent clinical studies have demonstrated that intracisternal administration of recombinant tissue plasminogen activator(rt-PA) can facilitate the normal clearing of blood from the subarachnoid space. Urokinase, a first generation fibrinolytic agent, has been used to liquify such clots with some success. Therefore, recombinant tissue plasminogen activator, a second generation fibrinolytic drug that may be safer and more effective, is studied to evaluate its dosage to lyse clots in vitro and reactivity in the brain parenchyme. Methods: Intracerebral hematomas were created by stereotactically injecting 2ml of clotted autogenous blood into the brain parenchyme of total 28 anesthetized adult cats (weighting 3.8 to 4.1 kg). The control animals (group A) received 1 ml of normal saline injected into the clots and the experimental animals received each 0.1 mg of rt-PA (group B), 0.5mg of rt-PA (group C) and 1 mg of rt-PA (group D) at 6 hours after the clot injection. Results: 1. The amount of remained clots after lysing the hematomas were as follows: $1.80{\pm}0.17ml$ in group A, $1.65{\pm}0.23ml$ in group B, $0.61{\pm}0.37ml$ in group C and $0.52{\pm}0.34$ in group D. The result indicated that hematomas in rt-PA treated groups (C & D) were lysed better than the control group. 2. At least 0.5mg of rt-PA should be required for the lysis of 2ml of hematomas. 3. Light microscopic examination revealed no histological evidence of hemorrhage in tissue sections from each brain. Conclusion: Recombinant tissue plasminogen activator may be safely and effectively employed for the lysis of intracerebral hematomas in animal model.

• 한국재료학회지
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• 제30권8호
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• pp.406-412
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• 2020

SrMoO₄:RE³⁺ (RE=Dy, Sm, Tb, Eu, Dy/Sm) phosphors are prepared by co-precipitation method. The effects of the type and the molar ratio of activator ions on the structural, morphological, and optical properties of the phosphor particles are investigated. X-ray diffraction data reveal that all the phosphors have a tetragonal system with a main (112) diffraction peak. The emission spectra of the SrMoO₄ phosphors doped with several activator ions indicate different multicolor emissions: strong yellow-emitting light at 573 nm for Dy³⁺, red light at 643 nm for Sm³⁺, green light at 545 nm for Tb³⁺, and reddish orange light at 614 nm for Eu³⁺ activator ions. The Dy³⁺ singly-doped SrMoO₄ phosphor shows two dominant emission peaks at 479 and 573 nm corresponding to the ⁴F_9/2→⁶H_15/2 magnetic dipole transition and ⁴F_9/2→⁶H_13/2 electric dipole transition, respectively. For Dy³⁺ and Sm³⁺ doubly-doped SrMoO₄ phosphors, two kinds of emission peaks are observed. The two emission peaks at 479 and 573 nm are attributed to ⁴F_9/2→⁶H_15/2 and ⁴F_9/2→⁶H_13/2 transitions of Dy³⁺ and two emission bands centered at 599 and 643 nm are ascribed to ⁴G_5/2→⁶H_7/2 and ⁴G_5/2→⁶H_9/2 transitions of Sm³⁺. As the concentration of Sm³⁺ increases from 1 to 5 mol%, the intensities of the emission bands of Dy³⁺ gradually decrease; those of Sm³⁺ slowly increase and reach maxima at 5 mol% of Sm³⁺ ions, and then rapidly decrease with increasing molar ratio of Sm³⁺ ions due to the concentration quenching effect. Fluorescent security inks based on as-prepared phosphors are synthesized and designed to demonstrate an anti-counterfeiting application.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.161-162
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• 2017

As the use of cement increases with the development of modern society along with the increase of buildings, environmental pollution intensifies and researches on industrial byproducts are continuing. Research on blast furnace slag and fly ash as industrial byproducts is increasing, and research on industrial byproducts such as polysilicon sludge and paper ash used in this study is increasing. Blast furnace slag, which is one of the industrial byproducts, has been widely studied as a material used with cement. However, in this study, we fabricated lightweight matrix of polysilicon sludge and paper ash replaced based on blast furnace slag, and performed SEM analysis.

• 한국재료학회지
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• 제29권6호
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• pp.356-362
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• 2019

$BaSiO_3:RE^{3+}$ (RE = Sm or Eu) phosphor powders with different concentrations of activator ions are synthesized using the solid-state reaction method. The effects of the concentration of activator ions on the structural, photoluminescent, and morphological properties of the barium silicate phosphors are investigated. X-ray diffraction data reveals that the crystal structure of all the phosphors, regardless of the type and the concentration of the activator ions, is an orthorhombic system with a main (111) diffraction peak. The grain particles agglomerate together to form larger clusters with increasing concentrations of activator ions. The emission spectra of the $Sm^{3+}$-doped $BaSiO_3$ phosphors under excitation at 406 nm consist of an intense orange band at 604 nm and three weak bands centered at 567, 651, and 711 nm, respectively. As the concentration of $Sm^{3+}$ increases from 1 to 5 mol%, the intensities of all the emission bands gradually increase, reach maxima at 5 mol% of $Sm^{3+}$ ions, and then decrease significantly with further increases in the $Sm^{3+}$ concentration due to the concentration quenching phenomenon. For the $Eu^{3+}$-doped $BaSiO_3$ phosphors, a strong red emission band at 621 nm and several weak bands are observed. The optimal orange and red light emissions of the $BaSiO_3$ phosphors are obtained when the concentrations of $Sm^{3+}$ and $Eu^{3+}$ ions are 5 mol% and 15 mol%, respectively.

• 한국건설순환자원학회논문집
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• 제2권2호
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• pp.166-171
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• 2014

기포콘크리트의 재료 중 시멘트는 제조과정 중에 $CO_2$를 다량 발생시키기 때문에 지구 환경적인 측면에서 커다란 문제가 되고 있지만, 아직까지 시멘트를 대체할 수 있는 대체재에 대한 연구 개발이 미흡한 실정이다. 또한, 발포제는 압축강도가 낮고 고가인 단점이 있다. 이 때문에 강도와 경량 등의 성능 개선과 친환경적인 재료의 사용이 필요한 실정이다. 이에 본 연구에서는 시멘트와 발포제를 대체하기 위해 고로슬래그와 제지애시를 사용하여 경량 경화체를 제조하고자 하였으며, 강도 및 경량성을 보완하기 위해 플라이애시와 폴리실리콘 슬러지를 사용하여 실험을 실시하였다. 그 결과, 플라이애시를 사용한 경화체는 Plain 보다 낮은 밀도를 나타내었으나 강도보완에는 취약하였으며, 폴리실리콘 슬러지를 사용한 경우는 3%치환한 경화체가 압축강도는 Plain보다 다소 낮지만 겉보기 밀도의 감소가 큰 것으로 나타났다.

• 한국세라믹학회지
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• 제29권11호
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• pp.851-854
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• 1992

It was grown ZrO2:10 mol% Y2O3 single crystals doped with 1 wt% of rare earth metal ion (Ce, Pr, Nd, Er, Eu) by Skull Method. Grown crystals showed Ce:orange-red, Pr:golden-yellow, Nd:lilac, Er:pink, Eu:light pink due to dopant effect. It was examined color centers in light absorption pattern of visible region (λ= 300~700 nm); in as grown samples, absorption by Ce4+, (Pr4+, Pr3+), Nd3+, Er3+, Eu3+ ions were important, and in samples after vacuum annealing, decrease of absorption by Pr4+ ion and increase of absorption by Pr3+ ion was important, and absorption by Ce3+, Eu2+ was important due to reduction of activator.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1276-1278
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• 2009

A novel blue emitting $Ca_{1-x}Mg_2Si_3O_9:Eu_x$ phosphor was synthesized by the solid state reaction and its photoluminescence properties were optimized by controlling concentration of the activator contents and substituting concentration of Ca ion by Sr ion. The photoluminescence (PL) showed that this phosphor is efficiently excited by ultraviolet (UV)-visible light in the wavelength range from 200 to 410 nm. Also this phosphor emits intensely blue light with a broad peak at around 450 nm.