• Title/Summary/Keyword: engineered surface

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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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    • v.13 no.1
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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
    • Journal of Food Hygiene and Safety
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    • v.35 no.4
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    • pp.304-311
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    • 2020
  • Galacto-oligosaccharides (GOS) are prebiotics that have a beneficial effect on human health by promoting the growth of probiotic bacteria in the gut, in addition to having various applications in the food industry. GOS are generally produced from lactose in a reaction catalyzed by β-galactosidase. Synthesis of GOS from whey permeate (WP) (ultrafiltration of whey, concentrated then spray dried) using surface engineered β-galactosidase in Pichia pastoris (P. pastoris) is a novel method to convert waste into a valuable product. Cell-surface display is the expression of peptides and proteins on the surface of living cells by fusing them to functional components of cells. Surface engineered cells have many potential uses. The Flo1p flocculation functional domain, thought to be located near the N terminus, recognizes and adheres non-covalently to cell-wall components such as α-mannan carbohydrates, causing reversible aggregation of cells into flocs.

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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    • 2005.07a
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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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Friction Property for Angles of Micro-crosshatch Grooved Surface Pattern under Lubricated Sliding Contact (마이크로 Crosshatch 그루우브 표면패턴의 각도에 따른 미끄럼 마찰특성)

  • Chae, Young-Hun
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.1 s.190
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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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    • v.6 no.2
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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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    • v.9 no.1_2
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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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    • v.4 no.1
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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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Dispersive white-light interferometry using polarization of light for thin-film thickness profile measurement (편광분리 분산 분산형 백색광 간섭계를 이용한 박막두께형상측정법)

  • Ghim Y.S.;Kim S.W.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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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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