• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1997.10a
• /
• pp.129-133
• /
• 1997

본 연구에서는 LiNbO$_3$ 단결정 소재의 광손상에 대한 저항성을 향상시키는 첨가물로 잘 알려져 이쓴 MgO 및 ZnO를 첨가하여 육성한 조화용융조성(congruent melting composition)의 LiNbO$_3$ 단결정의 domain 구조는 이들 dopants를 첨가함에 따라 single domain에서 ring 형태의 주기적인 domains으로 변화함을 확인하였고, 첨가된 이온이 domain 형성에 미치는 영향을 전자현미경(SEM-WDS)으로 관찰하였다. 또한, 육성한 [Li1-5xNb5(x-y)Mg(or Zn)5y]Nb1-4x+3yO3 단결정들의 유전율(전이온도) 변화 및 광학적 특성[광투과율, 굴절률]을 측정하여 undoped LiNbO$_3$단결정과 비교하였다. 첨가물을 첨가함에 따라 전이온도는 약 20~3$0^{\circ}C$정도 증가하였으며, 10-3 order의 굴절률 변동치를 나타내었다. 또한, 육성된 결정들의 투과율은 대체로 70~80%를 나타내었고, 첨가물을 첨가함에 따라 흡수단과 OH- 흡수 band는 단파장쪽으로 각각 약 5~10nm, 40nm이동됨을 확인하였다. 이는 LiNbO$_3$단결정의 광손상 저항성이 향상되었음을 간접적으로 보여주는 결과이다.

• Membrane Journal
• /
• v.19 no.3
• /
• pp.244-251
• /
• 2009

In this research the polyethersulfone hollow fiber membrane was used to separate Sulfur Hexafluoride ($SF_6$) which is the one of the six greenhouse gases from Air ($N_2$). The effects of the non-solvent (Acetone, Ethanol) type, air-gap and post-treatment (surface silicon coating) were investigated by the structure and performance of the membranes. The structure change of the membrane was examined by scanning electron microscope. The single gas permeation using $N_2$, $SF_6$ through the membrane surface coated with silicon showed maximum 7.64 perm-selectivity improved 3.4 times.

• Parasites, Hosts and Diseases
• /
• v.33 no.3
• /
• pp.155-164
• /
• 1995

The location of actin and myosin of the several stages of Cwptosporinium parvum was observed. The tissue antigen of C. pcruum was prepared through immunosuppression of IgG mice with Depomedrol . The thin sectioned specimens, which were incubated with the IgG fraction of the rabbit polyclonal antibodies raised against chicken back muscle actin and bovine uterus myosin, were treated with 10 nm gold-conjugated goat anti-rabbit IgG, Electrodense particles were located mainly on the pellicles of all observed developmental stages of the parasites. The number of actin gold particles in the cytoplasm increased when the parasite was dividing actively as in case of meronts. Especially in macrogametocytes, a lot of actin and myosin particles were synthesized and storaged as amilopectin-like bodies. There were many actin gold particles along the microspikes of cytoplasmic membranes in various developmental stages. The actin and myosin observed in this study may play important roles to control the shape of the parasites and movement of cytoplasmic membranes as cvtoskeletal proteins.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2010.05a
• /
• pp.59-59
• /
• 2010

ZnO는 II-VI 족 화합물 반도체로써 상온에서 큰 엑시톤 결합에너지 (~60 meV) 를 가지며 밴드갭이 3.37 eV인 직접 천이형 반도체로 잘 알려진 물질이다. 이러한 ZnO의 물리적 특성은 광학소자로 상용화된 GaN와 유사하기 때문에 LED나 LD등의 광 소자 재료로 주목 받고 있다. 또한 ZnO는 3족 원소 (In, Ga, Al)를 도핑 함으로써 전기적 특성 제어가 가능한 장점을 가지고 있다. 본 연구는 펄스레이저 증착법 (Pulsed Laser Deposition)을 이용하여 Si (111) 기판 위에 ZnO:In 박막을 성장 시켰으며, 도핑된 indium 양에 따른 ZnO 박막의 배향성 변화를 관찰 하였다. X-선 회절 분석법 (X-ray diffraction), 탐침형 원자현미경 (Atomic Force Microscope) 그리고 투과전자 현미경 (Transmission Electron Microscope)을 측정하였다. XRD 측정 결과 un-doped ZnO 박막은 (002) 방향으로 c-축 우선성장 하였다. 그러나 ZnO 박막내의 Indium 양이 증가 할수록 (002) 방향에서 (101), (102), (103) 등의 (101) 방향으로 성장이 변화 하였으며 5 at.% 이상에서는 (100) 방향의 성장이 관찰 되었다. TEM 측정 결과 un-doped ZnO 박막은 columnar 구조로 성장 되었으나, Indium 양이 증가할수록 column의 size가 감소하며, 5 at.% 이상에서 columnar 구조 성장이 거의 관찰되지 않는다. AFM 결과에서는 Indium 양이 증가 할수록 박막의 표면거칠기와 결정립 크기가 감소하였다.

• Applied Microscopy
• /
• v.33 no.4
• /
• pp.291-298
• /
• 2003

Exposure to stressful stimuli is known to activate the peripheral sympathetic nervous system and the adrenal gland. In this study, we evaluated the effects of high-salt diet on the mouse adrenal medulla using the tyrosine hydroxylase (TH) immunohistochemistry and the transmission electron microscopic observation. Immunoreactivity for TH was increased after high-salt diet. Especially, the TH immunoreactivity was stronger in 4 days high-salt diet mouse than that of 4 weeks. TH immunoreactivity was mainly present in the cytoplasm and granules of the noradrenaline cells. After high-salt diet, the noradrenaline cells exhibited the ultrastructural alterations consisting of areas of empty cytoplasm, expanded granules, and some damaged mitochondria. These results suggest that high-salt diet may be a factor of stressful stimuli on the mouse.

• Applied Microscopy
• /
• v.41 no.2
• /
• pp.117-122
• /
• 2011

Sperm morphology of Pipistrellus savii velox was examined by transmission electron microscope. The sperm head of P. savii velox was bullet in shape. The sperm head was 3.1 ${\mu}m$ in length, whose posterior 3.0 ${\mu}m$ was occupied by a nucleus with 1.8 ${\mu}m$ in width. The segmented columns were about 14~15 in number. The total number of mitochondrial gyres was 57. Number of 1, 5, and 6 of the outer dense fibers were larger than the others. A fibrous sheath and longitudinal column of the principal piece were evidence, but the fibrous sheath was not seen at the end piece. In the present study, the length of the sperm head of P. savii velox were very shorter than those of other bats.

• Applied Microscopy
• /
• v.32 no.3
• /
• pp.257-263
• /
• 2002

Microstructural investigations of $(Li_{1/2}Pr_{1/2})TiO_3$ (LPT) complex perovskite compounds were carried out using X-ray diffractometry and transmission electron microscopy. LPT has not only the ordering of A-site cation deficiencies but also has the antiphase and inphase tilting of oxygen octahedron and the antiparallel shift of cations. Both the antiphase boundaries and the ferroelastic domains are present in the microstructure. Spinodal decomposition is found in the microstructure. The measured dielectric properties were ${\varepsilon}_r=84.6,\;Q\;{\Large f}_o=776\;GHz,\;{\tau}_{f}=-233.66ppm/^{\circ}C$.

• Applied Microscopy
• /
• v.41 no.1
• /
• pp.31-35
• /
• 2011

The fine structures of the sperm morphology in the Myotis daubentonii ussuriensis were observed by transmission electron microscope. The results showed that the sperm head revealed bullet shaped, the width was showed a slender more than toward the posterior region to anterior region of nucleus. The sperm head was about $4.5{\mu}m$ in length, being about $2.0{\mu}m$ in width. The nuclear length was $4.3{\mu}m$, occupied most of the sperm head. The nucleus and acrosome were separated by the apical body. The neck region was composed the basal plate, capitulum and segmented columns. The segmented columns were about 12 to 14 in number and connected with the outer dense fibers of the middle piece. The mitochondria sheath were arranged like the thread of a screw, and the total number of mitochondrial gyres were 57. The satellite fibers were observed irregularly among the outer dense fibers in the middle piece. Except the middle piece they are not observed in the principal and end pieces of the tail. In general, the tail show axoneme composed of a 9+2 microtubular pattern, and microtubules of the end piece were arranged irregularly.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.14 no.5
• /
• pp.362-368
• /
• 2021

A homeotropic liquid crystal (LC) alignment state on rubbed fluorinated self-assembled monolayers (FSAMs) is described according to alkyl chain length. A simple procedure, gas-phase method, for the preparation of FSAM was used. The average optical transmittance in the visible light range of FSAMs were 76.63% to 78.21%, which were superior to the conventional polyimide layer having a transmittance of 75.89%. In addition, the excellent homeotropic LC alignment characteristics of FSAMs were observed through pretilt angle measurement and polarized optical microscope images. By measuring the contact angles and the surface energies of FSAMs, it was confirmed that pretilt angles of LC molecules increased according to the alkyl chain length. High optical transparency and uniform homeotropic LC alignment characteristics of FSAMs showed the possibility of FSAMs as an LC alignment layers.

• Applied Microscopy
• /
• v.29 no.3
• /
• pp.343-351
• /
• 1999

The structures of the fertilized egg envelope from three species, three-spot gourami (Trichogaster trichopterus), pearl gourami (Trichogaster leeri) and marble gourami (Trichogaster trichopterus trichopterus) belong to Belontiidae were observed, utilizing light, scanning and transmission electron microscopes. In all three species, the fertilized eggs were the colorless, transparent, spherical, adhesive and pelagic type. A large oil droplet was located in vitelline membrane of the fertilized egg. The egg envelopes have a single micropyle, which is thought to the pathway of sperm in the area of the animal pole. Specially, the micropyle of three-spot gourami was similar to that of marble gourami which is subspecies of three-spot gourami. An outer surface of the fertilized egg envelope was arranged by grooves in all three species. The fertilized egg envelopes consists of two distinct layers; an adhesive outer layer and an inner layer with high electron density. In conclusion, the morphological similarity of the fertilized egg, micropyle, outer surface and transverse section of the fertilized e9g envelope seems to be an indication of the Belontiidae.