• 제목/요약/키워드: Engineered surface

검색결과 127건 처리시간 0.026초

Engineered nanoparticles in wastewater systems: Effect of organic size on the fate of nanoparticles

  • Choi, Soohoon;Chen, Ching-Lung;Johnston, Murray V.;Wang, Gen Suh;Huang, Chin-Pao
    • Membrane and Water Treatment
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    • 제13권1호
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    • pp.29-37
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    • 2022
  • To verify the fate and transport of engineered nanoparticles (ENP), it is essential to understand its interactions with organic matter. Previous research has shown that dissolved organic matter (DOM) can increase particle stability through steric repulsion. However, the majority of the research has been focused on model organic matter such as humic or fulvic acids, lacking the understanding of organic matter found in field conditions. In the current study, organic matter was sampled from wastewater treatment plants to verify the stability of engineered nanoparticles (ENP) under field conditions. To understand how different types of organic matter may affect the fate of ENP, wastewater was sampled and separated based on their size; as small organic particular matter (SOPM) and large organic particular matter (LOPM), and dissolved organic matter (DOM). Each size fraction of organic matter was tested to verify their effects on nano-zinc oxide (nZnO) and nano-titanium oxide (nTiO2) stability. For DOM, critical coagulation concentration (CCC) experiments were conducted, while sorption experiments were conducted for organic particulates. Results showed that under field conditions, the surface charge of the particles did not influence the stability. On the contrary, surface charge of the particles influenced the amount of sorption onto particulate forms of organic matter. Results of the current research show how the size of organic matter influences the fate and transport of different ENPs under field conditions.

Systematic Review on Application of Whey Towards Production of Galacto-oligosaccharide Using β-Galactosidase Enzyme from Pichia pastoris

  • Ramachandran, C;Oh, Deog-Hwan
    • 한국식품위생안전성학회지
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    • 제35권4호
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    • pp.304-311
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    • 2020
  • Galacto-oligosaccharides(GOS)는 프로바이오틱스 미생물의 성장을 증진시켜 인류 건강에 유익한 작용을 갖게 하는 프리바이오틱스이며 식품 산업에서 다양한 활용성을 갖는다. GOS는 보통 β-galactosidase에 의해 촉매 반응이 일어난 lactose로부터 생성된다. 한편, 세포 표면 발현은 살아있는 세포 표면의 펩타이드와 단백질을 세포의 기능성 성분에 융합시켜 발현시키는 것이다. 표층 발현 세포는 다양한 잠재적 이용가치를 갖는다. N 말단 부근에 위치하는 것으로 생각되는 Flo1p 응집 functional domain은 세포의 flocs로의 가역적인 응집을 유발하면서 α-mannan carbohydrates와 같은 세포벽 성분과 비공유결합을 한다. 한외여과한 유청을 농축, 분무건조한 유청막투과액(Whey Permeate, WP)을 이용하여 β-galactosidase 재조합 Pichia pastoris (P. pastoris) 로 표층 발현 처리 (surface engineering)하는 GOS의 합성법은 폐기물을 활용하는 새로운 효율적인 방법이라 할 수 있다.

Plastic Displays - Latest Developments In Polyester Film For Plastic Electronics

  • Hashimoto, K.;MacDonald, W.A.;Rollins, K.;MacKerron, D.;Eveson, R.;Rustin, R.A.;Rakos, K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.620-622
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    • 2005
  • DuPont Teijin Films (DTF) have developed a family of films engineered specifically for the flexible electronics market. $Teonex^{(R)}Q65A$ is a biaxially oriented crystalline polyester with an engineered surface and it is emerging as a competitive material for the base substrate in OLED displays and active matrix backplanes. This contribution will describe the properties of this film, its uniquely different property set compared to amorphous high performance films and discuss examples of the film in use in flexible electronic applications.

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마이크로 Crosshatch 그루우브 표면패턴의 각도에 따른 미끄럼 마찰특성 (Friction Property for Angles of Micro-crosshatch Grooved Surface Pattern under Lubricated Sliding Contact)

  • 채영훈
    • 한국정밀공학회지
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    • 제24권1호
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    • pp.79-84
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    • 2007
  • Some surface pattern of tribological application is an attractive technology of engineered surface. Therefore, friction reduction is considered to be necessary for improved efficiency of machine. This study investigated the effect of friction property for angles of micro-crosshatch groove surface pattern on bearing steel using pin-on-disk test. We obtain sample which can be fabricated by photolithography process. We discuss the friction property depend on an angle of crosshatch groove surface pattern. We can verify the lubrication mechanism as Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter under the lubrication condition. It was found that the friction coefficient was related to angle of crosshatch groove pattern on contact surface.

Friction Behavior of Micro-scale Groove Surface Patterns Under Lubricated Sliding Contact

  • Chae Young-Hun
    • KSTLE International Journal
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    • 제6권2호
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    • pp.51-57
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    • 2005
  • Surface texturing of tribological applications is an attractive technology of engineered surface. Therefore, reduction of friction is considered to be necessary for improved efficiency of machines. The current study investigated the potential of textured micro-scale grooves on bearing steel flat mated with pin-on-disk. We discuss reducing friction due to the influence of sliding direction at surface pattern. We can indicate lubrication mechanism as a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter for the lubrication condition. It was found that the friction coefficient was changed by the surface pattern and sliding direction, even when surface pattern was the same. It was thus verified that micro-scale grooves could affect the friction reduction considerably under mixed and hydrodynamic lubrication conditions. The lubrication regime influences the friction coefficient induced by the sliding direction of groove pattern. The friction coefficient depends on a combination of resistance force and hydrodynamic.

Artificial Adhesive Surfaces Mimicking Gecko Setae: Novel Approaches in Surface Engineering

  • Singh, R. Arvind;Yoon, Eui-Sung
    • KSTLE International Journal
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    • 제9권1_2호
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    • pp.13-16
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    • 2008
  • Surface Engineering is a field closely related to Tribology. Surfaces are engineered to reduce adhesion, friction and wear between moving components in engineering applications. On the contrary, it is also necessary to have high adhesion between surfaces so as to hold/stick surfaces together. In this context, surface engineering plays an important role. In recent times, scientists are drawing inspiration from nature to create effective artificial adhesive surfaces. This article provides some examples of novel surface engineering approaches conducted by various research groups worldwide that have significantly contributed in the creation of bio-inspired artificial adhesive surfaces.

Regiospecific Orientation of Single-chain Antibody and Atomic Force Microscope (AFM) Images

  • Kyusik Yun;Park, Seonhee;Hyeonbong Pyo;Kim, Seunghwan;Lee, Sooyeul
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제4권1호
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    • pp.72-77
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    • 1999
  • An antibody containing a genetically engineered lipid group at the N-termunus and a hexahistidinyl tag at the C-terminus (Lpp-scF-His6) was immobilized in an oriented manner on the surface of liposome. Liposomes, consisting of antibody and phosphatidyl-choline, have been prepared and imaged by AFM. For AFM visualization, the resulting liposomes were bound on the surface of mica by two different mechanisms. The histidine tags present in the antibody molecules of the immonuliposome were anchored to the NiCl2 treated mica surface. Alternatively, the immunoliposomes were immunochemically bound on antigen-coated mica surface. Both approaches yielded liposomes which were clearly imaged without damage by AFM in ambient condition.

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편광분리 분산 분산형 백색광 간섭계를 이용한 박막두께형상측정법 (Dispersive white-light interferometry using polarization of light for thin-film thickness profile measurement)

  • 김영식;김승우
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.565-568
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    • 2005
  • We describe a new scheme of dispersive white-light interferometer that is capable of measuring the thickness profile of thin-film layers, for which not only the top surface height profile but also the film thickness of the target surface should be measured at the same time. The interferometer is found useful particularly for in-situ inspection of micro-engineered surfaces such as liquid crystal displays, which requires for high-speed implementation of 3-D surface metrology.

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