• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.57-62
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• 2022

The plasma resistance of multi-component glasses containing La, Gd, Ti, Zn, Y, Zr, Nb, and Ta was analyzed in this study. The plasma etching was performed via inductively coupled plasma-reactive ion etching (ICP-RIE) using CF₄/O₂/Ar mixed gas. After the reaction, the glass with a low fluoride sublimation temperature and high content of P, Si, and Ti elements showed a high etching rate. On the other hand, the glass containing a high fluoride sublimation temperature component such as Ca, La, Gd, Y, and Zr exhibited high plasma resistance because the etch rate was lower than that of sapphire. Glass with low plasma resistance increased surface roughness after etching or nanoholes were formed on the surface, but glass with high plasma resistance showed little change in surface microstructure. Thus, the results of this study demonstrate the potential for the development of plasma-resistant glasses (PRGs) with other compositions besides alumino-silicate glasses, which are conventionally referred to as plasma-resistant glasses.

• 연구논문집
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• s.25
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• pp.193-205
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• 1995

Plasma spray coating technology is essential for the microsemiconductor processes based on the electronic and computer industry, and extend gradually the range of application for up-to-date industry such as diesel engine and gas turbine components. These thechonoogies may be applied to the components requiring wear-resistance, heat resistance, fatigue-resistance, and corrosion-resistance. In this research, plasma spray technology was selected for the wear resistant coatings as the most proper technique. The final goal of this study is to improve the wear resistance through establishment of coating soft-ware, and basic research for industrialization of the technology concerned.

• Journal of Nutrition and Health
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• v.16 no.3
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• pp.200-208
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• 1983

The present studies were designed to compare the effects of both dietary fat levels and P / S ratio on lipid components in plasma and tissues. Changes in plasma HDL-cholesterol, cholesterol and TG, and also in tissue cholesterol and TG were determined in young rats fed diets providing total dietary fat as 10%, 25% or 45% of calories and P / S ratio as 0.2 or 4.0. Plasma cholesterol levels were getting higher as dietary fat levels increased at P / S 0.2. Plasma cholesterol was lower in rats fed dietary fat either 25% or 45 %, each with P / S 4.0. But at 10% no change in plasma cholesterol were observed by P / S 4.0 because of a possible insufficiency of the absolute amount of PUFA. HDL-cholesterol was rather less sensitive to the modification of dietary fat level, but was reduced in rats fed diets of P / S 4.0 at either 25% or 45% fat, even though HDL-cholesterol were increased in the group of 10% with P / S 0.2. Total cholesterol per g- liver were significantly increased as dietary fat levels increased. Liver cholesterol levels were higher in rats fed diets of P / S 4.0 at higher fat levels (25% or 45%) which possibly suggested that a reduction of plasma cholesterol by high PUFA diet was not at least from a decreased synthesis of cholesterol in liver. However, in muscle no significant differences were found by feeding high P / S ratio at each levels of fat. At 10% fat level, compared to 25% or 45%, cholesterol level was lower in g-liver but higher in g- muscle. Plasma TG was decreased as more dietary fat were supplied at P / S ratio, but no consistant response obtained at low P / S ratio. TG per g-liver were reduced by feeding P / S 4.0 diet at 10% or 45% fat level but no differences were found in muscle. P / S 4.0 diet was more efficient in lowering plasma cholesterol TG and HDL-cholesterolt levels only if fat level was more than 25% of the total calories And young rats were more resistant to dietary fat modification.

• Journal of Powder Materials
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• v.26 no.2
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• pp.132-137
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• 2019

Tungsten carbide (WC) hard materials are used in various industries and possess a superior hardness compared to other hard materials. They have particularly high melting points, high strength, and abrasion resistance. Accordingly, tungsten carbide hard materials are used for wear-resistant tools, cutting tools, machining tools, and other tooling materials. In this study, the WC-5wt.%Co, Fe, Ni hard materials are densified using the horizontal ball milled WC-Co, WC-Fe, and WC-Ni powders by a spark plasma sintering process. The WC-5Co, WC-5Fe, and WC-5Ni hard materials are almost completely densified with a relative density of up to 99.6% after simultaneous application of a pressure of 60 MPa and an electric current for about 15 min without any significant change in the grain size. The average grain size of WC-5Co, WC-5Fe, and WC-5Ni that was produced through SPS was about 0.421, 0.779, and $0.429{\mu}m$, respectively. The hardness and fracture toughness of the dense WC-5Co, WC-5Fe, WC-5Ni hard materials were also investigated.

• Journal of Photoscience
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• v.9 no.2
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• pp.47-50
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• 2002

Raft is a distinctive membrane domain enriched in a certain class of lipids, cholesterol, and proteins observed on the plasma membrane. Growing evidence has revealed that such membrane domains play key roles in signal transduction, fertilization, development, transmitter release, and so on. Recently, we have isolated raft-like detergent-resistant membrane (DRM) fraction from bovine photoreceptor rod outer segments. Transducin and its effecter, cGMP-phosphodiesterase, elicited stimulus-dependent translocation between detergent-soluble membrane and DRM. This suggested potential importance of such distinct membrane domains in vertebrate phototransduction. Here, we will discuss physiological meaning of the translocation of major components of cGMP cascade to raft-like membrane in phototransduction. We would like to propose a hypothesis that raft-like membrane domains on the disk membrane are the place where cGMP cascade system could be quenched.

• Journal of Life Science
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• v.25 no.6
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• pp.715-723
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• 2015

Insects represent the largest class within the animal kingdom in terms of species number. Humans had been utilized insect in the broad area, including food, agriculture, industry, pharmaceuticals and so on. At present, insects are emerging as a leading group for identifying and extracting novel bioactive substances due to enormous number and a high nutritional value. Insects rely on a suite of systemic response to resist infection such as immune cells, hemocytes, activation of enzymes cascades, and antimicrobial peptide/protein. Among the substances, antimicrobial peptides (AMPs) are main components of potent antimircrobial innate defense system into the insect hemolymph. AMPs raise influential candidate as avenue to resolve the development of antibiotic-resistant microbial organism. Insect AMPs are classified into four main classes: cecropins, insect defensins, glycine/proline-rich peptides. Insect AMPs have been purified, over 150. In this review, AMPs derived from several insects were summarized including honey bee, dung beetle, butterfly and longicorn beetle. These peptides almost exhibited potent antimicrobial activities against human microbial pathogens without causing remarkable hemolysis to erythrocytes excluding melittin, and their mode of action(s) are based on disruption of the plasma membrane or fungal apoptosis. Therefore, study of insect AMPs is expected to be useful for designing novel therapeutic antimicrobial applications.