• JSTS:Journal of Semiconductor Technology and Science
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• 제8권3호
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• pp.239-243
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• 2008

In this study, Bi-Sb thin film structure was prepared by thermal evaporation method. The electrical, optical transmission and structural characteristics of the prepared samples were introduced before and after thermal annealing process. At temperature of $500^{\circ}C$, the absorption of the structure was improved to reach 97% at near-infrared region. As well, the thermal annealing caused to reduce the bulk resistance of the Bi-Sb thin film structure. The morphology of Bi-Sb structure was also improved by thermal annealing as characteristic islands of the structure appear clearly in form hexagonal areas distinct from each other. This study is aiming to examine such structures if they are employed as photonic devices such as photodetectors, LED's and optical switches.

• 대한수의학회지
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• 제22권1호
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• pp.63-66
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• 1982

Authors encountered a case of bovine viral leukosis in a young cattle (10 months old) with the following findings; Main clinical symptoms observed were emaciation, digestive disorder, and marked enlargement of superficial lymph nodes. Biopsied specimen of the lymph nodes revealed characteristic histological picture of bovine leukosis. A severe degree of leukocytosis (108,000/cmm) accompanied by marked lympocytosis (96%=103,680/cmm) was detected from the hematological examination of peripheral blood. Most of the lympocytes(94%=101,520) were large-sized, immature, and abnormal in their morphology. In addition, a pronounced anemia (1.78 million/cmm) without regenerative evidence of erythrocyte was noted. The serum of the patient showed positive reaction against gp antigen of bovine leukosis virus in agar-gel diffusion test.

• 한국진공학회지
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• 제7권s1호
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• pp.134-139
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• 1998

Amorphous fluorocarbon (a-C:F) is of interest for low dielectric interlayer material, but in this work we applied this material to FED field emitter. N-doped a-C:F films were deposited by inductively coupled plasma chemical vapor deposition (ICPCVD). The Raman spectra were measured to study the film structure and inter-band optical absorption coefficients were measured using Perkin-Elmer UV-VIS-IR spectrophotometer and optical band gap was obtained using Tauc's plot. XPS spectrum and AFM image were investigated to study bond structure and surface morphology. Current-electric field(I-E) characteristic of the film was measured for the characterization of electron emission properties. The optimum doping concentration was found to be [N2]/[CF4]=9% in the gas phase. The turn-on field and the emission current density at $[N_2]/[CF_4]$=9% were found to be 7.34V/$\mu\textrm{m}$ and 16 $\mu\textrm{A}/\textrm{cm}^2$ at 12.8V/$\mu\textrm{m}$, respectively.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.270-274
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• 2004

Aircraft composite structure with honeycomb core experiences core crush problem in manufacturing. To prevent core crush additional processes are needed such as core stabilization and prepreg material tie-down and this is the cause of increasing cost. Recent study shows that high friction prepreg prevent core crush without additional process. This paper presents the analysis of high frictional material which attracts lots of interests through physical property, mechanical property and microscopic morphology and the cause of friction.

• 한국공작기계학회논문집
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• 제12권5호
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• pp.53-58
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• 2003

Wear debris can be collected from the lubricants of operating machinery and its morphology is directly related to the fiction condition of the interacting materials from which the wear particles originated in lubricated machinery. But in order to predict and estimate working conditions, it is need to analyze the shape characteristics of wear debris and to identify. Therefore, if the shape characteristics of wear debris is identified by computer image analysis and the neural network, The four parameter (50% volumetric diameter, aspect, roundness and reflectivity) of wear debris are used as inputs to the network and learned the friction. It is shown that identification results depend on the ranges of these shape parameters learned. The three kinds of the wear debris had a different pattern characteristic and recognized the friction condition and materials very well by neural network. We resented how the neural network recognize wear debris on driving condition.

• 한국재료학회지
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• 제12권5호
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• pp.327-333
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• 2002

In order to obtain the oxidation layer for SiC MOS, the oxide layers by thermal oxidation process with dry and wet method were deposited and characterized. Deposition temperature for oxidation layer was $1100^{\circ}C$~130$0^{\circ}C$ by $O_2$ and Ar atmosphere. The oxide thickness, surface morphology, and interface characteristic of deposited oxide layers were measurement by ellipsometer, SEM, TEM, AFM, and SIMS. Thickness of oxidation layer was confirmed 50nm and 90nm to with deposition temperature at $1150^{\circ}C$ and $1200{\circ}C$ for dry 4 hours and wet 1 hour, respectively. For the high purity oxidation layer, the necessity of sacrificial oxidation which is etched for the removal of the defeats on the wafer after quickly thermal oxidation was confirmed.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.676-677
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• 2006

Synthesis of zinc oxide nanorods, sheets and flower like structure were done by the sol-gel method using zinc acetate dihydrate and sodium hydroxide at $80^{\circ}C$ with 12 hours refluxing time nanorods, in case of as synthesized powder, with diameter of 20-60nm. Annealing at higher temperature (300 and $500^{\circ}C$,) in air ambient changes the morphology to sheet and flower like structure. The standard peak of zinc oxide was observed in IR at $523cm^{-1}$. The UV-VIS spectroscopy of zinc oxide shows a characteristic peak at 375nm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.6-8
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• 2002

In order to prepare magnetic recording layer with a good quality crystallographic characteristic. We prepared $Co_{77}Cr_{20}Ta_3$ layer for perpendicular magnetic recording media on slide glass substrate by Two-Step Methode. The thickness of magnetic layer was fixed 100 nm and buffer layer were varied from 10 to 50 nm, and input current was varied from 0.2[A] to 0.5[A]. The surface morphology and crystal orientation of the CoCrTa films were examined with XRD. Prepared thin films showed improvement of dispersion angle of c-axis orientation ${\Delta}{\theta}_{50}$ caused by inserting buffer layer.

• 한국표면공학회지
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• 제32권3호
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• pp.472-483
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• 1999

Hard coatings playa continuously increasing role in the field of tribology as well as for decorative applications. In both areas they are often also exposed to corrosive media. While especially hard nitride coatings show a high corrosion resistance for themselves, hard $coating_strate systems may suffer from a severe corrosion attack due to the defects in the coating structure (pores, pinholes) resulting from the PVD-typical film morphology. While a huge number of investigations cover the tribological properties, only limited studies deal with the corrosion behavjour of coating substrate systems and attempts are made to improve their corrosion resistance. The present paper shortly describes the corrosion mechanisms and repots characteristic examples of the system behaviour. Special emphasis is laid on recent investigations to improve the corrosion resistance by alloying, interlayers or multilayered coating structures.es.

• 식물분류학회지
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• 제49권3호
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• pp.265-268
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• 2019

An unrecorded Fissidens species, Fissidens protonemaecola Sakurai (Fissidentaceae, Bryophyta), was newly discovered in Korea during an investigation bryophyte flora. In this study, we examined the morphology of F. protonemaecola in Korea. This species was found in soil along a train through a shaded backslope of Mt. Bukbyeongsan (elev. 80 m) on Geojedo Island and on Mt. Gogeunsan (Oreum; elev. 280 m) on Jejudo Island, Korea. This species has dwarfish bud-like shoots scattered on persistent protonemata. An important feature of the protonemata is a diagnostic character of F. protonemaecola that clearly distinguishes it from other Fissidens species. Its Korean name is given as "Cho-rok-sil-bong-hwang-i-kki," inferred from the characteristic protonemata of the species.