• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1060-1062
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• 2002

Spherical and dense BAM phosphor particles were prepared by spray pyrolysis. The key idea of dense BAM particles is to lead gelation in droplets, which was successfully achieved by using the aluminum polycation as the precursor solution for the spray pyrolysis. The BAM phosphor particles prepared by spraying the aluminum polycation solution have completely spherical shape and dense structure. When directly applied to make phosphor film on the glass by the screen-printing method, the prepared spherical BAM phosphor particles showed better packing density and surface morphology than that of commercial one, which has irregular shape and large particle size. It was also found that the thermal degradation in the photoluminescence intensity for dense and spherical BAM particles was less than that of commercial one.

• Development and Reproduction
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• v.15 no.3
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• pp.239-247
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• 2011

Spermatogenesis and taxonomic values of mature sperm morphology of in male Septifer (Mytilisepta) virgatus were investigated by transmission electron microscope observations. The morphologies of the sperm nucleus and the acrosome of this species are the cylinder shape and cone shape, respectively. Spermatozoa are approximately 45-50 ${\mu}m$ in length including a sperm nucleus (about 1.26 ${\mu}m$ long), an acrosome (about 0.99 ${\mu}m$ long), and tail flagellum (about 45-47 ${\mu}m$). Several electron-dense proacrosomal vesicles become later the definitive acrosomal vesicle by the fusion of several Golgi-derived vesicles. The acrosome of this species has two regions of differing electron density: there is a thin, outer electron-dense opaque region (part) at the anterior end, behind which is a thicker, more electron-lucent region (part). In genus Septifer in Mytilidae, an axial rod does not find and also a mid-central line hole does not appear in the sperm nucleus. However, in genus Mytilus in Mytilidae, in subclass Pteriomorphia, an axial rod and a mid-central line hole appeared in the sperm nucleus. These morphological differences of the acrosome and sperm nucleus between the genuses Septifer and Mytilus can be used for phylogenetic and taxonomic analyses as a taxonomic key or a significant tool. The number of mitochondria in the midpiece of the sperm of this species are five, as seen in subclass Pteriomorphia.

• Current Photovoltaic Research
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• v.10 no.2
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• pp.39-48
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• 2022

A Se-containing Cu/SnSe₂/ZnSe precursor was employed to introduce S to the precursor to form Cu₂ZnSn(S,Se)₄ (CZTSSe) film. The morphology of CZTSSe films strongly varied with two different pre-annealing environments: S and N₂. The CZTSSe film with S pre-annealing showed a dense morphology with a smooth surface, while that with N₂ pre-annealing showed a porous film with a plate-shaped grains on the surface. CuS and Cu₂Sn(S,Se)₃ phases formed during the S pre-annealing stage, while SnSe and Cu₂SnSe₃ phases formed during the N₂ pre-annealing stage. The SnSe phase formed during N₂ pre-annealing generated SnS₂ phase that had plate shape and severely aggravated the morphology of CZTSSe film. The power conversion efficiency of the CZTSSe solar cell with S pre-annealing was low (1.9%) due to existence of Zn(S.Se) layer between CZTSSe and Mo substrate. The results indicated that S pre-annealing of the precursor was a promising method to achieve a good morphology for large area application.

• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.853-859
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• 1997

For asymmetric polyetherimide membranes having a dense layer gradient structure on the skin layer, the morphology change and pervaporation behaviors of water/isopropanol mixture through chemical modification of dense skin layer were investigated. The extent of the density was controlled by the evaporation, time, and when the evaporation time was increased from 0 min to 4 min, the permeation flux was decreased, the separation factor was increased. Also, the pervaporation behaviors of the polyetherimide membranes modified with sodium hydroxide solution, as the modification time of dense skin layer increased, the selectivity increased, and the permeation flux decreased. The morphology change identified by SEM shows that the density of dense skin layer tends to increase with increasing modification time, this result is consistent with above observations.

• The Korea Journal of Herbology
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• v.32 no.6
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• pp.49-54
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• 2017

Objectives : Bangki is commonly Sinomeni Caulis et Rhizoma (SC) in Korea. But it often confused with others such as Cocculi Radix (CR), Stephaniae Tetrandrae Radix (SR) and Aristolochiae Fangchi (AR) due to the similarity in herbal names and morphological characteristics. However, because all of these types of Bangi have different healing properties, they need to be differentiated. Methods : A discrimination on external features of original plants and external characteristics of herbal medicines was carried out using visual examination, stereoscope. For the examination of Internal characteristics of herbal medicines, tissues were dyed using fast green FCF, hematoxylin and safranin O, and the features were observed by the microscope. Results : In external morphology of original plants, the original plants of SC and AR were lignum plants and others were herbaceous plants. The leaf blade and the petiole were another discriminative criteria. In external morphology of herbal medicines, SR and AR have powders and others didn't. Also, SC and CR were determined by the dense of the radiation pattern in the cross section. In internal morphology of herbal medicines, SR and AR were distinguished by the dense of Stone cells. Moreover, SC and CR were different in the pattern of medullary ray and vascular bundle. Conclusions : The results above could be used as identification keys of Bangki. Moreover, these identifications might attribute as a fundamental material to further studies like physicochemical pattern analysis and biological reaction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.11
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• pp.1571-1577
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• 2013

Electrical tree structure is one of the most important influencing factors for electrical treeing characteristics in polymers. In this paper, we focused on the structure characteristics of electrical treeing in epoxy resins (original) insulation under different high-frequency voltages (60, 500, 1000Hz). Effects of voltage frequency on the ac electrical treeing phenomena in an epoxy resins were carried out in needle-plate electrode arrangement. To measure the treeing initiation and propagation, and the breakdown rate, constant AC of 10 kV with three different voltage frequencies (60, 500 and 1,000 Hz) was applied to the specimen in needle-plate electrode specimen at $30^{\circ}C$ of insulating oil bath. At 60 Hz, the treeing initiation time was 360 min and the propagation rate was $6.85{\times}10^{-4}mm/min$, and the morphology was dense branch type. As the voltage frequency increased, the treeing initiation time decreased and the propagation rate increased. At 1,000 Hz, the treeing initiation time was 0 min and the propagation rate was $7.81{\times}10^{-2}mm/min$, and the morphology was dense bush type.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.90-92
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• 2010

Staining profiles and bacterial morphology were compared in Xanthomonas citri pv. citri by a transmission electron microscopy. Four types of negative staining regimes were employed depending on culture media and heavy metal stains. The bacterial cells grown on LB agar media often appeared clustered on the supporting film. Meanwhile, individual bacterial cells could be readily found on the preparations from LB broth media. Typical rod-shaped cells (ca. $1\;{\mu}m$ in length) and their flagella were observed in either 2% uranyl acetate (UA) or 2% neutralized potassium phosphotungstate (PTA) staining. The UA-stained bacteria often showed relatively intact cell morphology and rather positively stained cells with a thin electron-dense stain depth around bacteria. The PTA-stained bacteria were characterized by the wrinkled cell surface where the stain was entrapped in grooves. In addition, distinct electron-dense stain depth was evident around the PTA-stained preparations. Numerous fimbriae could be mostly observed from the PTA-stained preparations of the two culture media, but not from the UA-stained preparations.

• Journal of the Korean institute of surface engineering
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• v.24 no.1
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• pp.24-24
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• 1991

Cr-N films were deposited on low-carbon steel sheets by the reactive arc-induced ion plating (AIIP). The influence of the deposition conditions (nitrogen pressure and substrate bias voltage) on the crystal orientation, morphology and microhardness of the Cr-N films has been investigated using x-ray diffractometer and scanning electron microscope. The impurities and contaminations on the surface and at the interface, and the layer-by-layer compositions of the film have been analyzed using scanning Auger multiprobe (SAM) and glow discharge spectroscope (GDS). The mixed state of Cr and Cr2N turned out to have a fine fibrous structure. The Cr2N films were deposited at a wide range of nitrogen flow rates. The orientations of Cr2N films were mainly (110) and (111), and the intensity of the (111) peak increased as the substrate bias voltage increased. The micorstructure of the Cr2N film was dense and no columnar structure was observed. The films in the mixed state of Cr2N and CrN were also dense without columnar structure. The maximum microhardness of the Cr-N films was 2400 kg/$\textrm{mm}^2$ at 10gf load.

• Journal of the Korean institute of surface engineering
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• v.49 no.5
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• pp.401-407
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• 2016

In this work, effect of zincate treatment of AZ91 Mg alloy on the following electrodeposition of copper was examined in a non-cyanide bath containing pyrophosphate ions in view of surface morphology and adhesion of the electrodeposited copper layer. Without zincate treatment, the electrodeposited copper layer showed very porous structure and poor adhesion. On the other hand, the copper layer electrodeposited on the zincate-treated surface showed dense structure and good adhesion. The dissolution rate of AZ91 Mg alloy after the zincate treatment appeared to decrease about 40 times in the copper pyrophosphate bath, as compared to that of the surface without zincate treatment. The porous morphology and poor adhesion of a copper layer on the AZ91 Mg alloy surface without zincate treatment were attributed to small number of nucleation sites of copper because of rapid dissolution of the magnesium substrate in the pyrophosphate bath. Based on the experimental results, it is concluded that the zincate treatment to form a conducting and protecting layer on the AZ91 Mg alloy surface is essential for successful electrodeposition of a copper layer on AZ91 Mg alloy with good adhesion and dense structure in the copper pyrophosphate bath.

• Journal of the Korean institute of surface engineering
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• v.25 no.1
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• pp.24-33
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• 1992

Cr-N films were deposited on low-carbon steel sheets by the reactive arc-induced ion plating (AIIP). The influence of the deposition conditions (nitrogen pressure and substrate bias voltage) on the crystal orientation, morphology and microhardness of the Cr-N films has been investigated using x-ray diffractometer and scanning electron microscope. The impurities and contaminations on the surface and at the interface, and the layer-by-layer compositions of the film have been analyzed using scanning Auger multiprobe (SAM) and glow discharge spectroscope (GDS). The mixed state of Cr and Cr₂N turned out to have a fine fibrous structure. The Cr₂N films were deposited at a wide range of nitrogen flow rates. The orientations of Cr₂N films were mainly (110) and (111), and the intensity of the (111) peak increased as the substrate bias voltage increased. The microstructure of the Cr₂N film was dense and no columnar structure was observed. The films in the mixed state of Cr₂N and CrN were also dense without columnar structure. The maximum microhardness of the Cr-N films was 2400 kg/㎟ at 10 gf load.