• ALGAE
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• v.25 no.1
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• pp.11-15
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• 2010

Two new genera of red algae, Madagascaria erythrocladioides West et Zuccarello and Pseudoerythrocladia kornmannii West et Kikuchi (Erythropeltidales, Compsopogonophyceae, Rhodophyta), were previously described using molecular analysis and confocal microscopy of isolates in laboratory culture. We examined the ultrastructure of both genera to compare with ultrastructure of other members of the class Compsopogonophyceae. Both genera had Golgi bodies not associated with mitochondria and chloroplasts with a peripheral encircling thylakoid similar to all other members of the class studied thus far. Confocal autofluorescence images showed that Madagascaria has a single round central pyrenoid while Pseudoerythrocladia has no pyrenoid. Our electron microscopic work confirms these initial observations. Tables and keys are presented that assist in interpreting cellular details of genera in the class Compsopogonophyceae.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.7
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• pp.450-455
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• 2015

For the practical application of a YBCO superconductor bulk, the superconductor bulk magnet with high magnetic field on a large area surface should be fabricated. To make this, YBCO single crystal bulks with fine $Y_2BaCuO_5$(Y211) particles have been prepared by the top-seed melt growth(TSMG) method with $YBa_2Cu_3O_x$, $Y_2O_3$, and $CeO_2$ mixing precursor. By using $Y_2O_3$ instead of $Y_2BaCuO_5$ as precursor, the manufacturing process became simpler and more economical. The microstructures, trapped field and critical current density of the various conditioned YBCO bulks have been observed, analyzed and measured. The different characteristic values of the several samples have been analyzed from the viewpoint of their microstructures. We have developed a $8{\times}12cm$ size superconductor bulk magnet, up to 3 T class, by using the 4 T class-high field superconducting magnetizer and confirmed the applicability of the transmission level circuit breakers by measuring the strength and speed of the superconductor bulk magnet actuator.

• Korean Journal of Metals and Materials
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• v.48 no.10
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• pp.901-906
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• 2010

The first stage blade of a gas turbine was operated under a severe environment which included both $1300^{\circ}C$ hot gas and thermal stress. To obtain high efficiency, a thermal barrier coating (TBC) and an internal cooling system were used to increase the firing temperature. The TBC consists of multi-layer coatings of a ceramic outer layer (top coating) and a metallic inner layer (bond coat) between the ceramic and the substrate. The top and bond coating layer respectively act as a thermal barrier against hot gas and a buffer against the thermal stress caused by the difference in the thermal expansion coefficient between the ceramic and the substrate. Particularly, the bondcoating layer improves the resistance against oxidation and corrosion. An inter-diffusion layer is generated between the bond coat and the substrate due to the exposure at a high temperature and the diffusion phenomenon. A thickness measurement result showed that the bond coat of the suction side was thicker than that of the pressure side. The thickest inter-diffusion zone was noted at SS1 (Suction Side point 1). A chemical composition analysis of the bond coat showed aluminum depletion around the inter-diffusion layer. In this study, we evaluated the properties of the bond coat and the degradation of the coating layer used on a $1300^{\circ}C$-class gas turbine blade. Moreover, the operation temperature of the blade was estimated using the Arrhenius equation and this was compared with the result of a thermal analysis.

• Journal of Technologic Dentistry
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• v.27 no.1
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• pp.131-153
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• 2005

The purpose of this study was to identify the accidents happened in the college dental laboratory technique classes and to realize the level of safety education for the dental laboratory technique major students. The research data were collected from a self-administered survey distributed to the conveniently selected college students whose majors were dental laboratory technology in Suwon, Daejeon, Daegu, Kimcheon, and Icsan. The study participants were 422 freshmen, sophomore and junior students in the selected cities. All collected survey responses were encoded and analyzed in SPSS 12.0. The findings were as follows. 1. The students who had any accidents in their laboratory classes were 36% and the other 64% answered 'no.' 2. Most injuries which the participants had were not significant. 3. The medical treatment periods of most injury cases were less than one week; however, approximately 20% of the self-reported injury cases reported that their treatment periods were longer than one week. 4. The body parts frequently injured from accidents were hands with 84.7% and arms, eyes, face, head, and legs in order. 5. Concerning the materials involved in the laboratory classes, most accidents happened when working with wax in 59.9%, with plaster in 52.3%, with wire in 39.8%, with alcohol in 34.6%, and casting iron in 22.2% in order. 6. The accident-prone laboratory methods were polishing with 53.5%, pickling or sanding with 17.4%, and casting or burning with 5.8% in order. 7. Most students wore their laboratory gowns well; however, few students wore mask before dust-involved jobs. Furthermore, only 57.1% students answered their laboratory fans worked during the polishing job. 8. Approximately 54% participant students answered that they took laboratory safety education when necessary only from the class instructors. 9. The 76.1% students responded that they needed laboratory safety education at least 1-2 times every semester. 10. The survey participants answered that the primary factors for injury prevention in their laboratory were taking safety education, wearing safety equipments, and providing safety-focused facilities. Concludingly, comprehensive evaluation and monitoring for potential risk factors from both the human side and the environment side should be continually provided to minimize the college laboratory accidents.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1178-1182
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• 2004

This paper presents web-based virtual laboratory system for electronic and digital circuit experiments. Through our virtual laboratory, the learners will be capable of learning the concepts and theories related to circuit experiments and how to operate virtual experimental equipments such as multimeters, function generators, digital oscilloscopes, DC power suppliers and bread board etc. The proposed virtual laboratory system is composed of important components: Principle Classroom to explain the concepts and theories of electronic and digital circuit operations, Simulation Classroom to provide a web-based simulator to the learners, Virtual Experiment Classroom to provide interactive multimedia contents about the syllabus of off-line laboratory class, Assessment Classroom, and Management System. With the aid of the management System every classroom is organically tied together collaboration to achieve maximum learning efficiency. We have obtained several affirmative effects such as high learning standard, reducing the total experimental hours and the damage rate for experimental equipments.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.302-306
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• 1998

In the previous study we described the antitumor activity of GLB, a protein-polysaccharide fraction of the growing tips of Ganoderma lucidum, against sarcoma 180 solid tu mor in ICR mice. In this study we investigated the stimulatory activity of GLB on macrophages. When analyzed using a flow cytometer, GLB ($100{\mu}g/ml$) was found to increase the phagocytic activity of the BALB/c mouse peritoneal macrophages as well as chicken macrophage BM2CL cells against FITC-labeled C.albicans by 55.2% and 21.2%, respectively. GLB also increased the spreading and the expression of MHC class II molecules of BM2CL cells as well as the mouse peritoneal macrophages. From these results, it is clear that GLB is a strong stimulator to the macrophages.

• Korean Journal of Poultry Science
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• v.38 no.2
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• pp.89-96
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• 2011

The outbreak of Newcastle disease occurred for the first time at a commercial chicken farm near Ulaanbaatar, Mongolia in August 2010. Newcastle disease virus (NDV) obtained from infected chickens in Mongolia was characterized by biological and molecular biological approches. Mongolian NDV isolate killed all of chicken embryos within 60 h in the mean death time assay, indicating virulent for chicken. A genomic region of 695 nts between nts 1055 of the M gene and 508 of the F gene was amplified by RT-PCR and sequenced. The deduced amino acid sequence of the F protein cleavage site was $^{112}RRQKRF^{117}$, which is a typical sequence of velogenic strains of NDV and is agreement with the result of the MDT assay. The sequence of the partial F gene (nts 47 to 435) was used for genotyping by phylogenetic analysis. The phylogenetic analysis showed that the Mongolian isolate was of genotype VII within class II of NDV. Further phylogenetic analysis on the genotype VII strains revealed that the isolates placed in a genetic sublineage of VIId and most closely related with velogenic strains of NDV circulating in Far-east Asian region especially China, suggesting the introduction of velogenic NDV into Mongolia from neighboring countries.

• Kyungpook Mathematical Journal
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• v.60 no.3
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• pp.599-627
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• 2020

In this paper, we characterize a class of biharmonic maps from and between doubly product manifolds in terms of theie warping function. Examples are constructed when all of the factors are Euclidean spaces.

• Bulletin of the Korean Space Science Society
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• 2007.04a
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• pp.37-37
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• 2007

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.9
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• pp.823-830
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• 2013

The purpose of this study is to develop a noise reduction device installed at the top of noise barrier for further decreasing of noise level of 400 km/h class high-speed railroad. For this, the frequency spectrum of 400 km/h class high-speed railroad was analyzed through the field noise test, and the tuning frequency was determined to design a noise reduction device. The noise reduction device was designed to have noise reduction performance of at least 3 dB(A) using the prediction method(2D BEM) and through the laboratory test with the prototype. Finally, the outdoor test showed that this device could decrease noise level of 400 km/h class high-speed railroad even more than 3 dB(A).