• 제목/요약/키워드: nano-approach

검색결과 348건 처리시간 0.035초

Visualizing the Peripheral Primo Vascular System in Mice Skin by Using the Polymer Mercox

  • Stefanov, Miroslav;Kim, Jungdae
    • 대한약침학회지
    • /
    • 제18권3호
    • /
    • pp.75-79
    • /
    • 2015
  • Objectives: As the peripheral part of the primo vascular system (PVS) is difficult to visualize, we used a vascular casting material Mercox injected directly into the skin to take advantage of a simple procedure to visualize PVS structures as primo vessels (PVs) and primo nodes (PNs) in the skin. Methods: Two colors of the polymer Mercox were injected into mouse skin. After a partial maceration of the whole body with potassium hydroperoxide solution, we anatomized it under a stereomicroscope to trace the Mercox that had been injected into the PVS. Results: Injection of Mercox directly into the skin allowed the PVs and the PNs to be visualized. This approach can fill the PVS when the material is ejected out of the PVs or PNs. The shapes, sizes, and topographic positions of the nodes and the vessels are the hallmarks used to identify the PVS in skin when Mercox is used as a tracer. Conclusion: The direct injection of the casting material Mercox into skin, with modified partial maceration procedures, is a promising method for visualizing the PVs and the PNs in the peripheral part of the PVS in skin. The polymer Mercox can penetrate through the primo pores of the primo vascular wall and fill the PVs and the PNs. The data prove that PVs and PNs exist on the hypodermal layer of the skin.

Clay-based Management for Removal of Harmful Red Tides in Korea: A Multi-perspective Approach

  • Choi, Moon-Hee;Lee, Soon Chang;Oh, You-Kwan;Lee, Hyun Uk;Lee, Young-Chul
    • 한국해양바이오학회지
    • /
    • 제6권1호
    • /
    • pp.17-25
    • /
    • 2014
  • Periodically, harmful algal blooms (HABs) have occurred, with impacts on various areas including public health, tourism, and aquatic ecosystems, especially aquacultured and caged fisheries. To prevent or manage invasions of HABs into fish farms on an emergency basis, many methods have been proposed. Frequently over the past 30 years in coastal countries, treatments of clay and clay mixed with polyaluminum chloride (PAC) and chitosan have been tested for HAB-removal effectiveness in both the laboratory and the field. In Korea, yellow loess clay (hwangto) has been dispersed using electrolytic clay dispensers, both to decrease the amount of yellow loess clay's usage in containers and enhance HAB-removal efficiency. However, this emergency method has limitations, among which is the requirement for more effective controlling agents for field applications. Thus, in this paper, we review technologies for clay-based red tides prevention and control and their limitations, and, further, introduce next-generation algicidal technologies for the emergency protection of fish farms.

나노구조 덴드리머의 광변위특성 (Photo Displacement Properties of Nano structure Organic Ultra Thin Films)

  • 송진원;최영일;조수영;김덕태;이우기;이경섭
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2004년도 추계학술대회 논문집
    • /
    • pp.23-26
    • /
    • 2004
  • Monolayers of lipids on a water surface have attracted much interest as models of biological membranes, but also as precursors of multilayer systems promising many technical applications. Until now, many methodologies have been developed in order to gain a better understand. Photoisomerization in monolayers of a novel azobenzene compound, azobenzene dendrimer, was investigated for the first time by means of the absorption spectrum and Maxwell displacement current(MDC) technique. Dendrimers are well-defined macromolecules exhibiting a tree-like structure, first derived by the cascade molecule approach According to the absorption spectrum, trans-to-cis conversion ratio was estimated to the third generation of azobenzene dendrimer deposited onto a glass substrate. Temperature-dependent induced charge with trans-cis isomerization was also measured by means of MDC technique.

  • PDF

Marangoni convection radiative flow of dusty nanoliquid with exponential space dependent heat source

  • Mahanthesh, Basavarajappa;Gireesha, Bijjanal Jayanna;PrasannaKumara, Ballajja Chandra;Shashikumar, Nagavangala Shankarappa
    • Nuclear Engineering and Technology
    • /
    • 제49권8호
    • /
    • pp.1660-1668
    • /
    • 2017
  • The flow of liquids submerged with nanoparticles is of significance to industrial applications, specifically in nuclear reactors and the cooling of nuclear systems to improve energy efficiency. The application of nanofluids in water-cooled nuclear systems can result in a significant improvement of their economic performance and/or safety margins. Therefore, in this paper, Marangoni thermal convective boundary layer dusty nanoliquid flow across a flat surface in the presence of solar radiation is studied. A two phase dusty liquid model is considered. Unlike classical temperature-dependent heat source effects, an exponential space-dependent heat source aspect is considered. Stretching variables are utilized to transform the prevailing partial differential system into a nonlinear ordinary differential system, which is then solved numerically via the Runge-Kutta-Fehlberg approach coupled with a shooting technique. The roles of physical parameters are focused in momentum and heat transport distributions. Graphical illustrations are also used to consider local and average Nusselt numbers. We examined the results under both linear and quadratic variation of the surface temperature. Our simulations established that the impact of Marangoni flow is useful for an enhancement of the heat transfer rate.

Development of Poly(methyl methacrylate)-Clay Nanocomposites by Using Power Ultrasonic Wave

  • Ryu, Joung Gul;Lee, Jae Wook;Kim, Hyungsu
    • Macromolecular Research
    • /
    • 제10권4호
    • /
    • pp.187-193
    • /
    • 2002
  • Several methods have been used to synthesize polymer-clay nanocomposites. In-situ polymerization with clay belongs to a classical way to develop nano-structured materials, while melt intercalation is being recognized as another useful approach due to its versatility and environmentally benign character. In this research, we prepared polymer-clay nanocomposites based on the poly (methyl methacrylate) and organically modified montmorillonite via two-stage sonication process. According to the unique mode of power ultrasonic wave, the sonication during processing led to enhanced breakup of the clay agglomerates and reduction in size of the dispersed phase. Optimum conditions to form stable exfoliated nanocomposites were studied for various compositions and conditions. It was found that a novel attempt carried out in this study yielded further improvement in the mechanical performance of the nanocomposites compared to those produced by the conventional melt mixing process, as revealed by DMA, XRD and TEM. And rheological properties of nanocomposites were measured by ARES. As a result, sonicated PMMA-clay nanocomposites exhibits enhanced properties such as storage modulus and thermal stability than that of neat PMMA.

WLP(Wafer Level Package)적용을 위한 SEMC(Sheet Epoxy Molding Compounds)용 Naphthalene Type Epoxy 수지의 경화특성연구 (Cure Characteristics of Naphthalene Type Epoxy Resins for SEMC (Sheet Epoxy Molding Compound) for WLP (Wafer Level Package) Application)

  • 김환건
    • 반도체디스플레이기술학회지
    • /
    • 제19권1호
    • /
    • pp.29-35
    • /
    • 2020
  • The cure characteristics of three kinds of naphthalene type epoxy resins(NET-OH, NET-MA, NET-Epoxy) with a 2-methyl imidazole(2MI) catalyst were investigated for preparing sheet epoxy molding compound(SEMC) for wafer level package(WLP) applications, comparing with diglycidyl ether of bisphenol-A(DGEBA) and 1,6-naphthalenediol diglycidyl ether(NE-16) epoxy resin. The cure kinetics of these systems were analyzed by differential scanning calorimetry with an isothermal approach, and the kinetic parameters of all systems were reported in generalized kinetic equations with diffusion effects. The NET-OH epoxy resin represented an n-th order cure mechanism as like NE-16 and DGEBA epoxy resins, however, the NET-MA and NET-Epoxy resins showed an autocatalytic cure mechanism. The NET-OH and NET-Epoxy resins showed higher cure conversion rates than DGEBA and NE-16 epoxy resins, however, the lowest cure conversion rates can be seen in the NET-MA epoxy resin. Although the NETEpoxy and NET-MA epoxy resins represented higher cure reaction conversions comparing with DGEBA and NE-16 resins, the NET-OH showed the lowest cure reaction conversions. It can be figured out by kinetic parameter analysis that the lowest cure conversion rates of the NET-MA epoxy resin are caused by lower collision frequency factor, and the lowest cure reaction conversions of the NET-OH are due to the earlier network structures formation according to lowest critical cure conversion.

Low Voltage and Rapid Response Time Electrophoretic Display

  • Lee, Y.E.;Cho, Y.T.;Choi, Y.G.;Park, S.C.;Lee, M.H.;Park, Y.M.;Kim, D.Y.;Kim, C.H.;An, C.H.;Kim, H.S.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
    • /
    • pp.360-363
    • /
    • 2009
  • In this paper, we describe new approach of ink particle fabrication method for electrophoretic display(EPD) with low voltage and rapid response time. Nano-size ink particles which fabricated using non-aqueous base modified emulsion process and micron-scale particles by non-solvent particle fabrication process are discussed. Finally, specially designed particles and panel structure fabricated considering the interactions between particle/particle, particle/media or particle/electrode dramatically reduce the driving voltages to ${\pm}$ 10V and improve the response time of less than 100msec and white reflectance of 58% for EPD using dielectric fluid as a medium. In case of EPD adapting micron-sized electrophoretic particles and a medium of air, the saturation voltage could be reduced to ${\pm}$ 40V and having white reflectance of 45% without scarification of electrophoretic mobility of the particles.

  • PDF

단백체 분석을 위한 일차원 및 이차원 역상크로마토그래피의 비교 (Comparison of 2-D RP-RP MS/MS with 1-D RP MS/MS for Proteomic Analysis)

  • 문평곤;조영은;백문창
    • 약학회지
    • /
    • 제54권5호
    • /
    • pp.377-386
    • /
    • 2010
  • Single-dimensional (1-D) and two-dimensional (2-D) LC methods were utilized to separate peptides from various sources followed by MS/MS analysis. Two-dimensional ultra-high performance liquid chromatography is a useful tool for proteome analysis, providing a greater peak capacity than 1-D LC. The most popular 2-D LC approach used today for proteomic research combines strong cation exchange and reversed-phase LC. We have evaluated an alternative mode for 2-D LC of peptides using 2-D RP-RP nano UPLC Q-TOF Mass Spectrometry, employing reversed-phase columns in both separation dimensions. As control experiments, we identified 129 proteins in 1-D LC and 322 proteins in 2-D LC from E. coli extract peptides. Furthermore, we applied this method to rat primary hepatocyte and a total of 170 proteins were identified from 1-D LC, and 527 proteins were identified from all 2-D LC system. The in-depth protein profiling established by this 2-D LC MS/MS from rat primary hepatocyte could be a very useful reference for future applications in regards to drug induced liver toxicity.

과학기술혁신정책의 새로운 접근방법으로서의 기술시스템: 그 개념 및 실제 적용사례 (A New Approach to Science and Technological Policy: Technological System and Its Application)

  • 성태경
    • 기술혁신학회지
    • /
    • 제9권4호
    • /
    • pp.715-739
    • /
    • 2006
  • 본 논문은 Carlsson and Stankielvicz(1991)에 의해 처음으로 소개된 기술시스템(Technological Systems; TSs) 의 개념을 발전시키고, 이를 우리나라 평판 프린팅 기술에 적용하였다. 특히 평판 프린팅 기술이 생산 공정기술로서 차세대 기술인 생명공학기술, 정보기술, 환경기술, 나노기술 등과 결합하면서, 하나의 기술시스템으로 창출 및 진화되는 동태적 과정을 분석하였다. 연구결과, 평판 프린팅 기술이라는 특정기술에 초점을 맞춘 기술시스템 접근방법이 국가혁신시스템, 지역혁신시스템, 산업클러스터 등 기존의 접근방법들이 추구하는 정책 목표를 보다 효과적으로 달성시킬 수 있음을 보이고, 이를 하나의 대안적 정책개념으로 제안하였다.

  • PDF

소각중성자 산란법을 이용한 도금층의 극미세 균열 형상의 비파괴적 분석 (Non-destructive Analysis of Nano-sized Crack Morphology of Electro-deposit by Using Small Angle Neutron Scattering)

  • 최용;신은주;한영수;성백석
    • 한국표면공학회지
    • /
    • 제49권2호
    • /
    • pp.111-118
    • /
    • 2016
  • A method to quantitatively analyze the defects formed by the hydrogen evolution during electroplating was suggested based on the theoretical approach of the small angle neutron scattering technique. In case of trivalent chrome layers, an isolated defect size due to the hydrogen evolution was about 40 nm. Direct and pulse plating conditions gave the average defect size of about 4.9 and $4.5{\mu}m$ with rod or calabash shape, respectively. Current density change of the pulse plating from $1.5A/dm^2$ to $2.0A/dm^2$ enlarged the average defect size from 3.3 to $7.8{\mu}m$. The defect morphology like rod or calabash was originated by inter-connecting the isolated defects. Small angle neutron scattering was useful to quantitatively evaluate defect morphology of the deposit.