• Animal Systematics, Evolution and Diversity
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• v.37 no.3
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• pp.225-228
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• 2021

Eleven Gonioctena species have been recorded in the Korean Peninsula. Most species in the genus have very similar coloration and morphology. The male genitalia is generally used as the only reliable diagnostic character differentiating closely related species, but it is still difficult to identify females to species accurately. Here, we determined the COI barcodes of two Gonioctena species described from Korea and give morphological descriptions. The interspecific genetic divergence (Kimura 2-parameter) among the Gonioctena ranged from 0.073 to 0.138 and averaged 0.108. The pairwise genetic distance between the two Korean species(0.102) is similar to the average interspecific divergence. We predict that these analyses will help to resolve taxonomic issues and find cryptic species.

• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.304-308
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• 2023

The spionid polychaete Scolelepis geniculata, originally described in Japan, is newly recorded in the Korean fauna. Specimens collected from the eastern and southern coasts of Korea between May 1999 and October 2002, stored in the invertebrate collection of the National Institute of Biological Resources, were examined based on their morphology. Scolelepis geniculata is morphologically most similar to S. yamaguchii from Japan and Korea but is distinguished by having branchiae separated from the notopodial lamellae in posterior chaetigers and notopodial prechaetal lamellae digitiform in anterior chaetigers instead of subtriangular. A detailed morphological description of S. geniculate, and an amended identification key to all Korean Scolelepis species is provided.

• Animal Systematics, Evolution and Diversity
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• v.40 no.4
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• pp.314-322
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• 2024

Two unrecorded ciliates from Korea, Nolandia nolandi (Kahl, 1930) Small and Lynn, 1985 and Nolandia sinica Chen et al., 2012, were collected from freshwater and brackish environments, respectively. Their morphology was examined based on the observation of living cells, protargol-impregnated, and scanning electron microscopy specimens. The phylogenetic analyses were performed using the 18S rRNA gene sequence obtained from a single cell of each species. The Korean population of N. nolandi is characterized by a size of 35-50×15-26 ㎛ in vivo, elliptical body, 13 or 14 somatic ciliary rows with 10-12 transverse circles and single caudal cilium. Nolandia sinica is characterized by a size of 50-65×15-25 ㎛ in vivo, elliptical body, 16-19 ciliary rows with 13 or 14 transverse circles and single caudal cilium. In the phylogenetic analyses, the genus Nolandia showed non-monophyly.

• Animal Systematics, Evolution and Diversity
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• v.28 no.3
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• pp.149-160
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• 2012

Heterotrichous ciliates were isolated from marine and brackish habitats in Korea, and their morphology, infraciliature and morphometrical characters were investigated using silver impregnated methods. These three Condylostoma species were identified as Condylostoma curva Burkovsky, 1970, C. minutum Bullington, 1940 and C. spatiosum Ozaki and Yagiu in Yagiu, 1944. The species of Condylostoma based on morphology are highly variable in most of characters and distinguished as following. Condylostoma curva is oval to elongate ellipsoidal, size about $245{\times}100{\mu}m$ in vivo, and conspicuously dark greenish brown with cortical granules on their surface, buccal cavity relatively large about 40% of body length, 5-11 macronuclear nodules, 4-8 frontal cirri serially arranged and 22-38 somatic kineties. Condylostoma minutum is elongate ellipsoidal and the size about $310{\times}55{\mu}m$ in vivo, buccal field about 35% of body length, 12-20 macronuclear nodules, adoral zone consisted of 82-107 membranelles, large and long one frontal cirrus and 38-44 somatic kineties. Condylostoma spatiosum is large elongate ellipsoidal, size about $670{\times}105{\mu}m$ in vivo, buccal cavity about 25% of body length, 11-25 macronuclear nodules, 111-144 adoral membranelles, membrane-like 2 frontal cirri, 49-74 somatic kineties. These three Condylostoma species are described here for the first time in Korea.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.336-336
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• 2011

Over the past decades, organic semiconductors have been investigated intensely for their potential in a wide range of optoelectronic device applications since the organic materials have advantages for very light, flexible and low cost device fabrications. In this study, we fabricated small-molecule organic solar cells (OSCs) based on chloro[subphthalocyaninato]boron(III) (SubPc) as an electron donor and $C_{60}$ as an electron acceptor material. Recently SubPc, a cone-shaped molecule with $14{\pi}$-electrons in its aromatic system, has attracted growing attention in small-molecule OSC applications as an electron-donating material for its greater open-circuit voltage (VOC), extinction coefficient and dielectric constant compared to conventional planar metal phthalocyanines. In spite of the power conversion efficiency (PCE) enhancement of small-molecule OSC using SubPc and $C_{60}$, however, the study on the interface between donor-acceptor heterojunction of this system is limited. In this work, SubPc thin films at various thicknesses were deposited by organic molecular beam deposition (OMBD) and the evolution of surface morphology was observed using atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM). We also investigated the influence of film thickness and surface morphology on the PCE of small-molecule OSC devices.

• Journal of Surface Science and Engineering
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• v.53 no.6
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• pp.312-321
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• 2020

Morphology of porous cobalt electro-deposits was systematically investigated as functions of cobalt precursors in the plating bath and applied cathodic current density with a special focus on cobalt nano-rod formation. It was proved that the concentration of cobalt precursor plays little effect on the morphology of cobalt electro-deposits at relatively low plating current density while it significantly affects the morphology with increasing plating current density. Such a dependence was discussed in terms of the kinetics of two competitive reactions of cobalt reduction and hydrogen evolution. Cobalt nano-rod structure was created at specific ranges of cobalt precursor content and applied cathodic current density, and its diameter and length varied with plating time without notable formation of side branches which is usually found during dendrite formation. Specifically, the nano-rod length was preferentially increased in relative short plating time (<15 s), resulting in higher aspect ratio of nano-rod with plating time. Whereas, both the nano-rod length and diameter were increased nearly at the same level in a prolonged plating time, making the aspect ratio unchanged. From the analysis of crystal structure, it was confirmed that the cobalt nano-rod preferentially grew in the form of single crystal on a dense poly-crystalline cobalt thin film initially formed on the substrate.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.98-98
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• 2010

Ion beam irradiation has been extensively used for surface modification of polymers, glassy metals and amorphous and crystalline materials at micron and submicron scales. The surface structures created by exposure to an ion beam range from dots, steps and one-dimensional straight wrinkles to highly complex hierarchical undulations and ripples. In general, the morphology of these nanoscale features can be selected by controlling the ion beam parameters (e.g. fluence and acceleration voltage), making ion beam irradiation a promising method for the surface engineering of materials. In the work, we presented that ion beam irradiation results in creation of a peculiar nanoscale dimple-like structure on the surface of polyimide - a common polymer in electronics, large scale structures, automobile industry, and biomedical applications. The role of broad Ar ion beam on the morphology of the structural features was investigated and insights into the mechanisms of formation of these nanoscale features were provided. Moreover, a systematic experimental study was performed to quantify the role of ion beam treatment time, and thus the morphology, on the coefficient of friction of polyimide surfaces covered by nanostructure using a tribo-experiment. Nano-indentation experiment were performed on the ion beam treated surfaces which shows that the hardness as well as the elastic modulus of the polyimide surface increased with increase of Ar ion beam treatment time. The increased of hardness of polyimide have been explained in terms of surface structure as well as morphology changes induced by Ar ion beam treatment.

• Korean Journal of Metals and Materials
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• v.46 no.3
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• pp.169-173
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• 2008

Characteristics of etching and induced surface morphology variation by wet-etching of n-type GaN were investigated using phosphoric acidic solutions. Generally, the etch-rate was increased as the temperature of the etch solutions was increased, and the highest etch rate of about $300{\AA}/min$ was achieved at the temperature of $180^{\circ}C$. The morphology variation of the etched surface was observed by optical microscopy and atomic force microscopy. Initially, high density of hexagonal holes or pits were formed on the etched surface at the time of 40 min with the bimodal size of $20{\mu}m$ or $5{\mu}m$, respectively. However, as the etching time was increased further, the lateral size of the hexagonal holes or pits was increased, and finally, joined and merged together at the time of 100 min. This means that the etching of n-type GaN by phosphoric acidic solutions proceeded through the lateral widening and the merging of initial holes and pits.

• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.271-278
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• 2005

Athough planetary nebulae (PNe) have been discovered for over 200 years, it was not until 30 years ago that we arrived at a basic understanding of their origin and evolution. Even today, with observations covering the entire electromagnetic spectrum from radio to X-ray, there are still many unanswered questions on their structure and morphology. In this review, we summarize recent theoretical and observational advances in PNe research, and discuss the roles of PNe in the chemical (atomic, molecular, and solid-state) enrichment of the galaxy and as tracers of the large scale structure of the Universe.

• Animal Systematics, Evolution and Diversity
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• v.23 no.2
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• pp.213-228
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• 2007

The kleptoparasitic spider subfamily Argyrodinae in Korea is reviewed with detailed illustrations and SEM photographs of male palpal organs. Five species belonging to four genera of Korean Argyrodinae spiders are redescribed and Argyrodes miltosus Zhu and Song, 1991 is synonymized with A. miniaceu. A key to the species of the Korean Argyrodinae spiders are also provided.