• 한국동물학회지
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• 제30권1호
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• pp.53-70
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• 1987

실험에 사용한 플라나리아는 Dugesia japonica Ichikawa et Kawakatsu로서 핵형분석에 의하여 종을 확인하였다, 이 종의 유조직을 구성하는 세포들의 세포화학적 및 미세구조적 특징을 밝히고자 본 실험을 행하였다. 세포화학적으로 방법으로는 hematoxyline-edsin, periodie, acid-schiff(PAS),PAS-alcian blue 반응 그리고 methylene blue-basic fuchisn 두으로 염색으 시행하였고, 유조직의 미세구조를 투과전자현미경으로 관찰하여 다음과 같은 결과를 얻었다. 유조직에는 두 조의 유조직 세포 이외에 봉상체형성세포와 종의 호염기성세포, 1종의 호산성세포 그리고 투명과립세포 7종의 과립세포가 관찰되었다. 1.유리유조직세포(Free parenchymal cell): 핵막 바로 주위에 세포질에는 다수의 chromatoid body가 존재하였고 세포질에 비하여 핵은 매우 컸다. 핵질에서는 뚜렷한 인을 관찰할 수 있었고 큰 염색질은 핵질에 균일하게 많이 분포되었다. 2.고정유세포( Fixed parenchymal cell): 이 세포는 불규칙한 모습으로 많은 세포돌기를 내고 있었고, 세포질에는 전자밀도가 매우 낮은 투명질에 과립성소포체, mitochondria 그리고 Golgi체등이 발달되어 었었다. 3.봉상체 형성세포(Rhabdite-forming cell): 세포질에는 전자밀도가 매우 높은 봉상체과립(0.3 x 0.9 $\mu$m)들을 포함하였으며 과립성소포체,mitochondria 그리고 Golgi체 등의 세포소기관도 매우 발달되어 있었다. 4. A형 호염기성과립세포(Basophilic granule cell type A): 세포질내에는 alcian blue에 강한 양성반응을 나타내고 전자밀도가 매우 높은 불규칙한 형태의 과립 (1.4 x 0.7 $\mu$m)들이 밀접되어 있었다. 5. C형 호기성과립세포(Basophilic granule cell type C): 세포질에는 PAS반응에 양성을 나타내는 작은 과립(0.2$\mu$m)들이 분산되어 있었다. 이 유형의 과립들은 근육층에서도 관찰되었다. 6. D형 호기성과립세포(Basophilic granule cell type D): 생긱기관 주위의 유조직에서만 관찰되었으며 세포질에는 PAS반응에 강한 양성을 보이고 또한 약한 eosinophilic도 나타내는 원형의 과립들이 대부분 집단을 이루웠다. 7. E형 호기성과립세포(Basophilic granule cell type E): 생식기관 주위의 유조직내에서만 관찰되었으며, 세포질내에는 PAS양성과립(약0.2$\mu$m)이 극소수 분산되어 있었다. 8. 호산성 과립세포(Eosinophilic granule cell): 세포질에는 eosinophilia를 나타내며, 전자밀도가 매우 높은 구형 또는 불규칙형과립(0.3$\times$0.2-8$\times$0.4$\mu$m)들이 존재하였으며, cisternae가 넓은 과립성소포체도 매우 발달되어 있었다. 9. 투명과립세포(Transparent granule cell): 본 실험에서 실시된 세포화학적 염색반응에서 음성을 나타내는 투명과립을 포함하고 있는 이같은 세포들은 D형 호염기성과립세포 주위에서 주로 관찰되었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.87-87
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• 2010

Photoelectrochemical (PEC) systems are promising methods of producing H2 gas using solar energy in an aqueous solution. The photoelectrochemical properties of numerous metal oxides have been studied. Among them, the PEC systems based on TiO2 have been extensively studied. However, the drawback of a PEC system with TiO2 is that only ultraviolet (UV) light can be absorbed because of its large band gap (3.2 - 3.4 eV). Two approaches have been introduced in order to use PEC cells in the visible light region. The first method includes doping impurities, such as nitrogen, into TiO2, and this technique has been extensively studied in an attempt to narrow the band gap. In comparison, research on the second method, which includes visible light water splitting in molecular photosystems, has been slow. Mallouk et al. recently developed electrochemical water-splitting cells using the Ru(II) complex as the visible light photosensitizer. the dye-sensitized PEC cell consisted of a dye-sensitized TiO2 layer, a Pt counter electrode, and an aqueous solution between them. Under a visible light (< 3 eV) illumination, only the dye molecule absorbed the light and became excited because TiO2 had the wide band gap. The light absorption of the dye was followed by the transfer of an electron from the excited state (S*) of the dye to the conduction band (CB) of TiO2 and its subsequent transfer to the transparent conducting oxide (TCO). The electrons moved through the wire to the Pt, where the water reduction (or H2 evolution) occurred. The oxidized dye molecules caused the water oxidation because their HOMO level was below the H2O/O2 level. Organic dyes have been developed as metal-free alternatives to the Ru(II) complexes because of their tunable optical and electronic properties and low-cost manufacturing. Recently, organic dye molecules containing multi-branched, multi-anchoring groups have received a great deal of interest. In this work, tri-branched tri-anchoring organic dyes (Dye 2) were designed and applied to visible light water-splitting cells based on dye-sensitized TiO2 electrodes. Dye 2 had a molecular structure containing one donor (D) and three acceptor (A) groups, and each ended with an anchoring functionality. In comparison, mono-anchoring dyes (Dye 1) were also synthesized. The PEC response of the Dye 2-sensitized TiO2 film was much better than the Dye 1-sensitized or unsensitized TiO2 films.

• 한국어류학회지
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• 제13권3호
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• pp.166-172
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• 2001

1995년 8월 제주도 근해에서 스쿠바 다이빙하여 연무자리돔의 산란보호행동을 관찰하였으며, 채집된 연무자리돔의 난은 부경대학교로 운반하여 부화, 사육하였다. 연무자리돔의 난은 평탄하고 단단한 기질의 산란소에 한층으로 부착되어 있었고, 수컷은 산란소 주위에서 접근해오는 다른 어종을 공격하는 산란보호행동을 나타내었다. 수정난은 무색투명하고, 타원형을 띠며, 부착사를 가진 침성부착난으로 난경은 장경이 0.73~0.88 mm, 단경이 0.50~0.56 mm이었다. 시간의 경과에 따른 난경의 변화는 T-test 결과 장경은 유의한 차이를 나타내었으나 (p<0.01) 단경은 유의한 차이가 없었다 (p>0.05). 수정난은 $23.0{\sim}25.5^{\circ}C$ 수온 범위에서 사육되었으며, 부화까지는 4~5일이 소요되었다. 부화자어는 척색장 1.10~1.61 mm로 21개의 근절을 가지고 있고 입은 닫힌 상태이나 항문은 열려 있으며, 항문전장은 척색장의 45.8%에 달하였고, 흑색소포는 두정부, 눈, 복강의 등쪽 및 꼬리의 배쪽 가장자리에 분포하였다. 부화자어의 난황과 유구는 부화 후 3~4일만에 완전히 흡수되어, 이 시기에 후기자어로 이행하였다. 부화 후 3일째 자어는 척색장 1.9~2.4 mm로 25개의 근절을 가지며, 빠르게 성장하였고, 부화 후 9일째 자어는 척색장 2.9 mm로 복부 등쪽에 처음으로 부레가 출현하였으며, 흑색소포는 형태적으로 커지면서 수적으로는 감소하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.286-286
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• 2016

Hexagonal boron nitride (hBN) is a dielectric insulator with a two-dimensional (2D) layered structure. It is an appealing substrate dielectric for many applications due to its favorable properties, such as a wide band gap energy, chemical inertness and high thermal conductivity[1]. Furthermore, its remarkable mechanical strength renders few-layered hBN a flexible and transparent substrate, ideal for next-generation electronics and optoelectronics in applications. However, the difficulty of preparing high quality large-area hBN films has hindered their widespread use. Generally, large-area hBN layers prepared by chemical vapor deposition (CVD) usually exhibit polycrystalline structures with a typical average grain size of several microns. It has been reported that grain boundaries or dislocations in hBN can degrade its electronic or mechanical properties. Accordingly, large-area single crystalline hBN layers are desired to fully realize the potential advantages of hBN in device applications. In this presentation, we report the growth and transfer of centimeter-sized, nearly single crystal hexagonal boron nitride (hBN) few-layer films using Ni(111) single crystal substrates. The hBN films were grown on Ni(111) substrates using atmospheric pressure chemical vapor deposition (APCVD). The grown films were transferred to arbitrary substrates via an electrochemical delamination technique, and remaining Ni(111) substrates were repeatedly re-used. The crystallinity of the grown films from the atomic to centimeter scale was confirmed based on transmission electron microscopy (TEM) and reflection high energy electron diffraction (RHEED). Careful study of the growth parameters was also carried out. Moreover, various characterizations confirmed that the grown films exhibited typical characteristics of hexagonal boron nitride layers over the entire area. Our results suggest that hBN can be widely used in various applications where large-area, high quality, and single crystalline 2D insulating layers are required.

• Current Photovoltaic Research
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• 제7권4호
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• pp.97-102
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• 2019

Bifacial and semitransparent hydrogenated amorphous silicon (a-Si:H) thin-film solar cells in p-i-n configuration were prepared with front and rear transparent conducting oxide (TCO) electrodes using plasma-enhanced chemical vapor deposition method. Fluorine-doped tin oxide and tin-doped indium oxide films were used as front and rear TCO contacts, respectively. Film thickness of intrinsic a-Si:H absorber layers were controlled from 150 nm to 450 nm by changing deposition time. The dependence of performance characteristics of solar cells on the front and rear illumination direction were investigated. For front illumination, gradual increase in the short-circuit current density (J_SC) from 10.59 mA/㎠ to 14.19 mA/㎠ was obtained, whereas slight decreases from 0.83 V to 0.81 V for the open-circuit voltage (V_OC) and from 68.43% to 65.75% for fill factor (FF) were observed. The average optical transmittance in the wavelength region of 380 ~ 780 nm of the solar cells decreased gradually from 22.76% to 15.67% as the absorber thickness was changed from 150 nm to 450 nm. In case of the solar cells under rear illumination condition, the J_SC increased from 10.81 to 12.64 mA/㎠ and the FF deceased from 66.63% to 61.85%, while the V_OC values were maintained at 0.80 V with increasing the absorber thickness from 150 nm to 450 nm. By optimizing the deposition parameters, a high-quality bifacial and semitransparent a-Si:H solar cell with 350 nm-thick i-a-Si:H absorber layer exhibited the conversion efficiencies of 7.69% for front illumination and 6.40% for rear illumination, and average visible optical transmittance of 17.20%.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.345-346
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• 2013

InGaN material is being studied increasingly as a prospective material for solar cells. One of the merits for solar cell applications is that the band gap energy can be engineered from 0.7 eV for InN to 3.4 eV for GaN by varying of indium composition, which covers almost of solar spectrum from UV to IR. It is essential for better cell efficiency to improve not only the crystalline quality of the epitaxial layers but also fabrication of the solar cells. Fabrication includes transparent top electrodes and surface texturing which will improve the carrier extraction. Surface texturing is one of the most employed methods to enhance the extraction efficiency in LED fabrication and can be formed on a p-GaN surface, on an N-face of GaN, and even on an indium tin oxide (ITO) layer. Surface texturing method has also been adopted in InGaN-based solar cells and proved to enhance the efficiency. Since the texturing by direct etching of p-GaN, however, was known to induce the damage and result in degraded electrical properties, texturing has been studied widely on ITO layers. However, it is important to optimize the ITO thickness in Solar Cells applications since the reflectance is fluctuated by ITO thickness variation resulting in reduced light extraction at target wavelength. ITO texturing made by wet etching or dry etching was also revealed to increased series resistance in ITO film. In this work, we report a new way of texturing by deposition of thickness-optimized ITO films on ITO nano dots, which can further reduce the reflectance as well as electrical degradation originated from the ITO etching process.

• 한국산업보건학회지
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• 제7권2호
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• pp.209-222
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• 1997

Authors surveyed the ground water near the waste disposed from a fiberglass production factory to confirm the presence of glassfiber in the water and to determine the effect of sampling conditions and storage on the recovery of fibrous materials in the ground water. Sample was collected at every 4 hours for 48 hours consecutively. After finishing the 48 hours sample, water sampling was done from each tap after repeated turning on and off the water for 30 seconds at each time. Sample was collected in the two 1.5 liter polyethylene bottle after vigorously shaking the bottle with the same water several times with the flowing tap water. At each paired sample, one bottle was stored stand still at room temperature, and the other sample was filtered immediately after sampling. Water was filtered on the Mixed Cellulose Ester filter with negative pressure. Each sample was divided into upper and lower layer. The other bottle was stored at room temperature standstill for 7 days and filtered in the same fashion as the other pair of sample did. Each MCE filter was divided into 4 pieces and one piece was treated with acetone to make it transparent. Each prepared sample was observed by two researchers under the light and polarizing microscopy, scanning electron microscopy and energy dispersive X-ra microanalysis. Fibers were classified by the morphology and polarizing pattern under the polarizing microscope, and count was done. 1. There was a significant fluctuation in number of the fibers, but there was no specific demonstrable pattern. 2. Non-polarizing fibers frequently disappeared after 7 days's storage. But cluster of fibers were found at the wall of the same container by scratching technique. 3. Polarizing fibers were usually found in between the filter and the manicure pasted area. Possible explanations for this phenomenon will be that either these fibers are very light or have electronic polarity. Hence, these fibers are not able to be attached on the surface of slide glass. 4. Under the scanning electron microscopic examination, the fibers which are not refractive under the light microscopy were identified as glassfiber. Other fibers which is refractive under the polarizing microscopy were identified as magnesium silicate fibers. It is strongly suggested that development of standardized method of sample collection and measurement of fibrous material in the water is needed.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.421-421
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• 2006

The light and energy-efficiency of classical liquid crystal displays is notoriously poor due to the use of absorption-based linear polarisers and colour filters. For instance, the light efficiency of PVAL polarisers is typically between 40 and 45 % and the colour filters have a typical efficiency below 35 % which results in a total light and energy-efficiency of the display below 10 %. In the past, a variety of polarizers were developed with an enhanced efficiency in generating linearly polarized light. Typically, these polarizers are based on the polarisationselective reflection, scattering or refraction of light i.e. one polarisation direction of light is directly transmitted to the LCD/viewer and the other polarization direction of light is depolarised and recycled which results in a typical efficiency for generating linearly polarized light of 70-85 %. Also, special colour filters have been proposed based on chiral-nematic reactive mesogens which increase the efficiency of generating colour. Despite the enormous progress in this field, a need persists for improved methods for generating polarized light and colour based on low cost optical components with a high efficiency. Here, the use of holographic phase gratings is reported for the generation of polarized light and colour. The phase grating are recorded in a photopolymer which is coated onto a backor frontlight for LCDs. Typically the recording is performed in the transmisson mode or in the waveguiding mode and slanted phase gratings are generated with their refractive index modulation at an angle between 20o and 45o with the normal of the substrate. It is shown that phase gratings with a high refractive index modulation and a high efficiency can be generated by a proper selection of the photopolymer and illumination conditions. These phase gratings coupleout linearly polarized light with a high contrast (> 100) and the light is directed directly to the LCD/viewer without the need for redirection foils. Dependent on the type of phase grating, the different colours are coupled-out at a slightly different angle which potentially increases the efficiency of classical colour filters. Moreover, the phase gratings are completely transparent in direct view which opens the possibility to use them in frontlights for LCDs. Holographic polarization gratings posses a periodic pattern in the polarization state of light (and not in the intensity of light). A periodic pattern in the polarization direction of linearly polarized light is obtained upon interference of two circularly polarized laser beams. In the second part of the lecture, it is shown that these periodic polarization patterns can be recorded in a linear photo-polymerizable polymer (LPP) and that such an alignment layer induces a period rotation in the director of (reactive and non-reactive) liquid crystals. By a proper design, optical components can be produced with only first order diffraction and with a very high efficiency (>0.98). It is shown that these diffraction gratings are potentially useful in projection displays with a high brightness and energy efficiency

• Composites Research
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• 제24권1호
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• pp.45-50
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• 2011

자체-감지능 있는 다기능성 나노복합소재를 위해, 투명하고 전도성 있는 카본나노튜브 (CNT)로 코팅된 폴리에틸렌 테레프탈레이트(PET)를 함침 방법으로 제조하였다. CNT 코팅의 전기적 광학적 특정의 변화는 함침 횟수와 CNT용액의 농도에 주로 의존하였다. 결과적으로, CNT 코팅의 표면저항과 투과도는 제조공정의 변수들에 따라 예민하게 조절되었다. CNT 코팅의 표면저항은 4점법과 이중 배열법에 의해 측정되었으며, 광학적 투과도는 UV 스펙트럼을 사용하여 평가하였다. CNT 코팅의 표면특성을 측정한 정적 및 동적 접촉각은 상호 일치함을 보여주었다. 함침 코팅수가 증가함에 따라, CNT코팅한 PET의 표면저항은 현저하게 저하했으나, 투명도는 CNT 네트워크의 특성으로 거의 감소하지 않았다. CNT와 인듐틴옥사이드 (ITO)의 계면 및 전기적 특성들은 피로 시험을 통하여 비교하였다. CNT는 2000회 반복 후에도 표면저항의 변화가 없는 반면에, ITO는 1000회 반복까지 표면저항의 급격한 증가를 보여주었다가 안정화하였다. 이는 형상비가 큰 CNT는 전기 접촉점을 계속 유지하는 반면에, 취성이 있는 ITO는 미세 균열이 발생하여 전지 접촉점을 많이 상실하기 때문이다.

• 한국광학회지
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• 제28권6호
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• pp.356-360
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• 2017

ITO는 높은 전기 전도도와 가시광선, 근적외선 영역에서 투명성을 가진다. LCD, OLED 등을 포함한 광학에 적용되는 부품들의 제조에 투명전극으로 ITO가 사용되고 있다. 가시광선 영역에서의 투명성과 높은 전도도 때문에 다양한 전기, 디스플레이 센서의 전극으로 이용되었다. 한 가지 사안은 기판의 특성에 충격없이 ITO, 금속 필름같은 특정한 영역의 층을 제거하는 부분이다. 레이저를 사용한 유리 위의 ITO 제거는 기존 방법에 비해 친환경적이다. 본 연구는 펨토초 레이저와 나노초 레이저를 사용하여 ITO를 제거하는 비교분석이다.