• Journal of Ceramic Processing Research
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• 제13권spc1호
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• pp.93-95
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• 2012

We report on the growth and characterization of the nano- and micro scale GaN structures selectively grown on the vertex of GaN stripes using the metal organic vapor phase epitaxy method and conventional photolithography technique. The triangular shaped nano- and micro GaN structures which have semi-polar {11-22} facets were formed only on the vertex of the lower GaN stripes. Crystalline defects reduction was observed by transmission electron microscopy for upper GaN stripes. We also have grown the InGaN/GaN multi-quantum well structures on the semi-polar facets of the upper GaN stripes. Cathodoluminescence images were taken at 366, 412 and 555 nm related to GaN band edge, InGaN/GaN layer and defects, respectively.

• Mycobiology
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• 제38권1호
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• pp.1-6
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• 2010

63 strains of Aspergillus section Fumigati were isolated from 17 samples of arable soil in a central province of Korea. Based on the results of genotypic and phenotypic analyses, they were identified as Aspergillus fumigatus, A. lentulus, Neosartorya coreana, N. fennelliae, N. fischeri, N. glabra, N. hiratsukae, N. laciniosa, N. pseudofischeri, N. quadricincta, N. spinosa and N. udagawae. Among these, N. fennelliae, N. hiratsukae, N. quadricincta, and N. udagawae had not been previously recorded in Korea. The diversity of Aspergillus section Fumigati species from arable soil in Korea is also addressed.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.16-21
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• 2013

In this paper, we report the effect of GaN/graded-composition AlGaInN/GaN quantum barriers in active regions on the electrical and optical properties of GaN-based vertical light emitting diodes (VLEDs). By modifying the aluminum composition profile within the AlGaInN quantum barrier, we have achieved improvements in the output power and the internal quantum efficiency (IQE) as compared to VLEDs using conventional GaN barriers. The forward voltages at 350 mA were calculated to be 3.5 and 4.0 V for VLEDs with GaN/graded-composition AlGaInN/GaN barriers and GaN barriers, respectively. The light-output power and IQE of VLEDs with GaN/graded-composition AlGaInN/GaN barriers were also increased by 4.3% and 9.51%, respectively, as compared to those with GaN barriers.

• 한국재료학회지
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• 제9권1호
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• pp.42-45
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• 1999

The room temperature optical transmission spectra of GaN /InGaN/GaN single quantum wells (SQW) and InGaN/GaN heterostructures grwon by low pressure metalorganic chemical vapor deposition have been measured. The dependence of the absorption edges of the GaN/InGaN/GaN SQW on the well width has been determined from the transmission spectra. The result shows that the absorption edge of GaN/InGaN/GaN SQW shifts towards lower energy as increasing the well width. The dependence of the absorption edges of the InGaN/GaN heterostructures on InN mole fraction has also been determined from the transmission spectra. The result is compared with calculated values obtained from Vegards's laws. Our result shows a good agreement with the calculated values.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.218-226
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• 2018

Nanometric Lactobacillus plantarum nF1 (nLp-nF1) is a biogenics consisting of dead L. plantarum cells pretreated with heat and a nanodispersion process. In this study, we investigated the immune-enhancing effects of nLp-nF1 in vivo and in vitro. To evaluate the immunostimulatory effects of nLp-nF1, mice immunosuppressed by cyclophosphamide (CPP) treatment were administered with nLp-nF1. As expected, CPP restricted the immune response of mice, whereas oral administration of nLp-nF1 significantly increased the total IgG in the serum, and cytokine production (interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-${\alpha}$)) in bone marrow cells. Furthermore, nLp-nF1 enhanced the production of splenic cytokines such as IL-12, TNF-${\alpha}$, and interferon gamma (IFN-${\gamma}$). In vitro, nLp-nF1 stimulated the immune response by enhancing the production of cytokines such as IL-12, TNF-${\alpha}$, and IFN-${\gamma}$. Moreover, nLp-nF1 given a food additive enhanced the immune responses when combined with various food materials in vitro. These results suggest that nLp-nF1 could be used to strengthen the immune system and recover normal immunity in people with a weak immune system, such as children, the elderly, and patients.

• 한국결정성장학회지
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• 제19권1호
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• pp.6-10
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• 2009

본 논문에서는 혼합소스(mixed-source) HVPE(hydride vapor phase epitaxy)방법으로 선택성장(SAC: selective area growth) GaN/AlGaN 이종접합구조의 발광다이오드를 r-plane 사파이어 기판 위에 제작하였다. SAG-GaN/AlGaN DH(double heterostructure)는 고온 GaN 버퍼층, Te 도핑된 AlGaN n-클래딩층. Gan 활성층. Mg 도핑된 AlGaN p-클래딩층. Mg 도핑된 GaN p-캡층으로 구성되어있다. GaN/AlGaN 이종접합구조의 발광다이오드의 특성을 알아보기 위해 SEM을 통한 구조적 분석과 전류-전압 측정(I-V: current-voltage measurement), 전류-광출력(EL: electroluminescence) 측정을 통하여 전기적, 광학적 특성을 평가하였다.

• Bulletin of the Korean Chemical Society
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• 제15권8호
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• pp.669-673
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• 1994

Coordination isomers of cis-(N-N)Pt(Glu) prepared by reaction of cis-(N-N)Pt($SO_4$) (N-N=2$NH_3$, ethylenediamine(en),(R,R)-1,2-diaminocyclohexane (DACH), N,N,N',N'-tetramethylethylenediamine (TMEDA)) with barium glutamate in water have been monitored and characterized by $^1H-NMR$, $^{13}C-NMR$, IR, and mass spectra. The reaction at room temperature affords the mixture of O,O'-and N, ${\alpha}$ O-chelated platinum(II) complexes. The O,O'-chelate initially formed isomerized to N,${\alpha}$O-chelate on standing for a long time or increasing temperature. The ratio of the two isomers at room temperature depends on the nature of the nitrogen donor coligand (N-N).

• 대한전자공학회논문지SD
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• 제46권4호
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• pp.10-14
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• 2009

본 논문에서는 항복 전압 특성을 향상시키기 위한 사다리꼴 게이트 구조의 AlGaN/GaN HEMT구조를 제안하였으며 그 실현 가능성을 2차원 소자 시뮬레이터를 통해 조사하였다. 사다리꼴 게이트 구조의 사용으로 드레인 방향의 게이트 모서리 부근에서 나타나는 전계의 집중을 효과적으로 분산되는 것이 시뮬레이션 결과에서 확인 되었다. 제안된 사다리꼴 게이트 AlGaN/GaN HEMT 소자 구조에서 2DEG 채널을 따라 형성되는 전계의 피크값은 4.8 MV/cm 에서 3.5 MV/cm 로 기존 구조의 AlGaN/GaN HEMT에 비해 30% 가량 감소하였으며, 그 결과로 인해 항복 전압은 49 V 에서 69 V 로 40 % 가량 증가하였다.

• Animal Systematics, Evolution and Diversity
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• 제40권3호
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• pp.167-210
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• 2024

Twelve species of cyclopoid copepods, including two new genera and ten new species, associated with polychaetes are described from Korea. The new taxa comprise Petalocopus planus n. gen. n. sp. in the Clausidiidae, Rhodinicola exilis n. sp. in the Clausiidae, Gastrodelphys vadicola n. sp. in the Gastrodelphyidae, Polyankylis estivalis n. sp. in the Polyankyliidae, Pentakela cylindrica n. gen. n. sp., Pseudanthessius oporinus n. sp. and P. petilus n. sp. in the Pseudanthessiidae, and Myxomolgus buanensis n. sp., M. dokdoicus n. sp. and Serpuliphilus antennatus n. sp. in the Sabelliphilidae. As characteristic features of the new genera, Petalocopus n. gen. has a pair of pedunculate suckers on the terminal segment of the antenna and an enlarged posterodistal seta on the second segment of antennule, and Pentakela n. gen. has five strong hooks on distal segments of antenna, three-segmented exopod and two-segmented endopod in legs 1 and 2, and one-segmented exopod and a lobate, rudimentary endopod in legs 3 and 4. The male of Maxilliclausia propria Kim, 2014 of the Clausiidae is recorded for the first time. Nereicola ovata Keferstein, 1863 known previously only in European waters is redescribed based on a newly collected female specimen from Korea.

• Journal of Species Research
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• 제7권4호
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• pp.251-290
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• 2018

A new genus and 28 new species are described: Collis n. gen. (type species Collis flavus n. sp.), Pholcus jindongensis n. sp., Pholcus piagolensis n. sp., Pholcus pyeongchangensis n. sp., Pholcus seorakensis n. sp., Pholcus uiseongensis n. sp., Octonoba bicornuta n. sp., Cnephalocotes ferrugineus n. sp., Diplocephaloides falcatus n. sp., Metopobactrus cornis n. sp., Pelecopsis bigibba n. sp., Pelecopsis brunea n. sp., Pelecopsis montana n. sp., Tapinocyba parva n. sp., Tapinocyba subula n. sp., Walckenaeria supercilia n. sp., Agyneta furcula n. sp., Arcuphantes chiakensis n. sp., Arcuphantes chilboensis n. sp., Arcuphantes longiconvolutus n. sp., Arcuphantes namweonensis n. sp., Arcuphantes pennatoides n. sp., Arcuphantes pyeongchangensis n. sp., Collis pusillus n. sp., Collis silvaticus n. sp., Doenitzius minutus n. sp., Nippononeta bituberculata n. sp., and Phrurolithus pennatoides n. sp. Seven species are new to Korea: Hylyphantes nigritus (Simon, 1881), Hypselistes australis Saito and Ono, 2001, Diplostyla concolor (Wider, 1834), Agyneta insulana Tanasevitch, 2000, Phoroncidia altiventris Yoshida, 1985, Theridula iriomotensis Yoshida, 2001, and Xysticus audax (Schrank, 1803).