• 한국식품영양과학회지
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• 제28권6호
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• pp.1293-1297
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• 1999

Effect of rice protein and lipid on rheological properties of gelatinized rice flour solutions(4%) with three rice varieties(Dongjin, Jinmi, Tamjin) known for varying taste of cooked rice was investigated with Haake viscometer. The rheological behaviors of all rice flour solutions were illustrated by Herschel Bulkley equation and exhibited pseudoplastic behavior with yield stress. When rice flour solutions treated with protease and dithiothreitol, there was decreased in flow behavior index value. Flow behavior index was decreased by dealbumin and deglutelin rice flour solutions among deprotein groups. The Jinmi rice flour solutions exhibited slightly lower consistency index than Dongjin and Tamjin. Defatted rice flour solutions exhibited lower consistency index than rice flour solutions, while dealbumin, deglutelin rice flour solutions exhibited high consistency index. Protease treated rice flour solutions exhibited increase in Dongjin and Tamjin. The yield stress was increased in sequence eating quality. Yield stress of defatted rice flour solutions was decreased, while deglutelin and rice starch flour solutions was increased. The time dependent charac teristics of all rice flour solutions appeared forming hysteresis loop and thixotropic behavior showed. The time dependent characteristics was appeared in sequence eating quality. Rice starch and deglutelin flour solutions appeared greatly time dependent characteristics, but defatted rice flour solutions appeared very little.

• Structural Engineering and Mechanics
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• 제11권1호
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• pp.89-104
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• 2001

This paper reviews the author's work on the development of relationships between solutions of the Kirchhoff (classical thin) plate theory and the Mindlin (first order shear deformation) thick plate theory. The relationships for deflections, stress-resultants, buckling loads and natural frequencies enable one to obtain the Mindlin plate solutions from the well-known Kirchhoff plate solutions for the same problem without much tedious mathematics. Sample thick plate solutions, deduced from the relationships, are presented as benchmark solutions for researchers to use in checking their numerical thick plate solutions.

• Journal of Advanced Marine Engineering and Technology
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• 제13권2호
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• pp.43-63
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• 1989

Various kinds of corrosion prevention methods have been developed. It is known that the method of electrochemical protection is more effective and economical than any other method on the large scale metal structures in corrosive solutions. Strong acid solutions such as nitric and sulfuric acid solutions are often used in industries, and the expensive stainless steel is almost exclusively used for the equipment that comes in contact with such acid solutions. However, it is more reasonable that carbon steel is used rather than stainless steel depending upon concentration of those acid solutions from the economical viewpoint. In this study, the typical strong acid solution such as nitric and sulfuric acid solutions are chosen for the experiment and the selected materials of specimen are the stainless steels of SUS 304L and SUS 316L, the carbon steels of SS 41, SM 50 and RA 32, and highly pure lead. Electrochemical protection diagrams can be drawn with data from the external cathodic and anodic polarization curves of SUS 304L, SUS 316L and SM 50 steels in 5-60% nitric acid solutions and from those polarization curves of SS 41, RA 32, SM 50 and SUS 316L steels, and highly pure lead in 2.5-98% sulfuric acid solutions at the slow scanning rate. The data obtained with using the determination method of the optimum cathodic protection potential, the Tafel extrapolation method and the characteristics of anodic polarization curves. The main results obtained from the diagrams are as follows: 1) In nitric acid solution : (1) Corrosion potentials exist in each of those corrosion zones on the stainless steels in the lower concentration than about 12% solutions and on the high tensile strength steels in the lower concentration than about 30% solutions, but the corrosion current (density) in each zone is small on the above mentioned former steels and large on the latter ones. (2) The stainless steels can be self-passivated in the higher concentration than 15% solutions, and the high tensile strength steels gives rise to the same phenomenon in the higher concentration than 35% solutions. (3) The stainless steels in the lower concentration than 60% solutions and the high tensile strength steels in the higher concentration than 35% solutions can be used without protection, but the latter steels must ve protected anodically in the lower conccentration than about 30% solutions. 2) In sufuric acid solution : (1) The carbon steels can be self-passivated in the higher concentration than 45% solutions, and the SUS 316L steel in higher concentration than 75% solutions and the lead in all concentration solutions also gives rise to the same phenomenon. (2) The lead in the lower concentration than 80% solutions and the SUS 316L steel in the higher concentration than 80% solutions can be used without protection. (3) The carbon steels in the higher concentration than 50% solutions also can be used without protecting economically, but the SUS 316L steel in the 20-70% solutions are considerably corrosive without protecting anodically.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.27-30
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• 1991

Recently, the phenomena of voltage instability have become major concern in power system, these phenomena are closely related to what are called multiple load flow solutions and calculation methods on these solutions have developed. The multiple solutions concerned with phenomena are pair solutions in heavy loaded contion. But conventional methods require much run time to find this pair solutions and unusual generation patten in the condition of multiple solutions. In this paper, by using concept of existence condition of multiple solutions, calculation method on the multiple load flow solutions is presented which find the pair solutions in light loaded condintion.

• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.143-152
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• 2010

Based on the Exp-function method and a suitable transformation, new generalized solitonary solutions including free parameters of the MDI and Sawada-Kotera equations with variable coefficients are obtained, form which solitary wave solutions and periodic solutions including some known solutions reported in open literature are derived as special cases. The free parameters in the obtained generalized solitonary solutions might imply some meaningful results in the physical models. It is shown that the Exp-function method provides a very effective and important new method for nonlinear evolution equations with variable coefficients.

• 한국안광학회지
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• 제1권2호
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• pp.13-18
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• 1996

콘택트렌즈 관리용액의 세포 독성을 배양 세포를 이용하여 검정한 결과 다음과 같은 결론을 얻었다. 총 19종의 용액중 세척액이 12종, 윤활액이 2종, 다목적액이 5종이었는데 이 용액을 1%에서 최고 10%까지의 농도로 처리하여 Neutral Red assay를 한 결과 세척액이 윤활액이나 보존액에 비하여 세포에 독성이 강한 것으로 나타났다. 특히 3종류의 세척액은 1%에서 세포가 모두 사망하여 매우 독성이 강하였는데 이는 세척 효과를 높이기 위해 독성이 강한 화학약품을 첨가하여 사용하는 것으로 판명되었다. 그런데, 놀라운 사실은 어떤 제품은 제조회사나 성분표시도 없이 유통되고 있어 국민의 안구 건강에 적신호가 되고 있다. 본 연구의 결과에 의하면 콘택트렌즈 관리용품도 철저한 독성 실험을 거쳐 시판되어야 할 것으로 사료된다.

• Korea-Australia Rheology Journal
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• 제15권3호
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• pp.151-156
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• 2003

In this research, experimental studies were performed to examine the rheological behavior of equimolar solutions of cetylpyridinium chloride (CPyCl) and sodium salicylate (NaSal) solutions with concentration. The surfactant solutions were prepared by dissolving 2 mM/2 mM - 80 mM/80 mM of surfactant/counterion in double-distilled water. It has been observed that the zero shear viscosity shows abrupt changes at two critical values of C^*$ and C^{**}$. These changes are caused by the switching of relaxation mechanism with concentration of CPyCl/NaSal solutions at those concentrations. The wall slip velocities of dilute and semidilute CPyCl/NaSal solutions show a dramatic increase with shear rate where the shear viscosity exhibits shear thickening behavior for dilute solutions and shear thinning behavior for semi-dilute solutions, respectively. Considering that the dramatic increase in wall slip velocity should be related to the formation of shear-induced structure (SIS) in the surfactant solution, the shear thickening behavior of semi-dilute solutions is caused by elastic instability unlike the case of dilute solutions.

• 한국표면공학회지
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• 제28권1호
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• pp.55-63
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• 1995

Alkaline solutions such as $NH_4$OH, choline and TMAH (($CH_3$)$_4$NOH) have been introduced in semiconductor wet processing of silicon wafers to control ionic and particulate impurities following etching in acidic solutions. These chemicals usually mixed with hydrogen peroxide and/or surfactants to control the etch rate of silicon. The highest etch rate was observed in $NH_4$OH solutions at a pH in alkaline solutions. It indicates that the etch rate depends on the content of $OH^{-}$ as well as cations of alkaline solutions. STM/AFM techniques were used to characterize the effect of alkaline solutions on silicon surface roughness. In SC1 (mixture of $NH_4$OH : $H_2$$O_2$ : $H_2$O) solutions, the reduction of the ammonium hydroxide proportion from 1 to 0.1 decreased the surface roughness ($R_{rms}$) from 6.4 to $0.8\AA$. The addition of $H_2$$O_2$ and surfactants to choline and TMAH reduced the values of $R_{p-v}$ and $R_{rms}$ significantly. $H_2$$_O2$ and surfactants added in alkaline solutions passivate bare silicon surfaces by the oxidation and adsorption, respectively. The passivation of surfaces in alkaline solutions resulted in lower etch rate of silicon thereby provided smoother surfaces.s.ces.s.

• 정보보호학회논문지
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• 제23권6호
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• pp.1037-1047
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• 2013

피싱(phishing) 공격의 피해가 증가함에 따라 그에 대한 대응책 및 관련 연구가 활발히 진행되어 왔다. 피싱 공격을 막는 솔루션(anti-phishing solutions)들은 웹브라우져(web-browser)의 보안 기능으로 혹은 보안 툴바(toolbar)의 형태로 다양하게 개발되었고, 그밖에도 이메일 필터링(email-filtering), 비밀 이미지 공유를 통한 서버 인증 강화 등의 방식으로 솔루션들이 개발되었다. 피싱 관련 연구로는 피싱 공격이 성공하는 이유에 대한 분석 연구, 피싱 공격을 막는 솔루션들이 효과적인지에 대해 사용자 입장에서 분석한 연구들이 발표되었다. 이 논문에서는 피싱 공격을 막는 다양한 종류의 솔루션들을 소개하고, 대표적인 솔루션들의 기술적 원리를 이해한다. 또한, 피싱 관련 연구 결과들을 함께 짚어봄으로써 피싱 공격을 막는 솔루션들이 개선되어야할 점들을 강조하여 살펴보고, 앞으로 피싱을 막기 위한 대책 연구가 진행되어야할 방향을 제시한다.

• Applied Microscopy
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• 제50권
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• pp.24.1-24.11
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• 2020

The development of the femtosecond laser (fs laser) with its ability to provide extremely rapid athermal ablation of materials has initiated a renaissance in materials science. Sample milling rates for the fs laser are orders of magnitude greater than that of traditional focused ion beam (FIB) sources currently used. In combination with minimal surface post-processing requirements, this technology is proving to be a game changer for materials research. The development of a femtosecond laser attached to a focused ion beam scanning electron microscope (LaserFIB) enables numerous new capabilities, including access to deeply buried structures as well as the production of extremely large trenches, cross sections, pillars and TEM H-bars, all while preserving microstructure and avoiding or reducing FIB polishing. Several high impact applications are now possible due to this technology in the fields of crystallography, electronics, mechanical engineering, battery research and materials sample preparation. This review article summarizes the current opportunities for this new technology focusing on the materials science megatrends of engineering materials, energy materials and electronics.