• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.3
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• pp.146-154
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• 2024

In this paper, we present a convenient liquid crystal (LC) molecular alignment method using brush hairs as an alternative to the rubbing process in the LC display industry. Titanium strontium yttrium zirconium oxide (TiSrYZrO) solution was prepared using a sol-gel process, and the TiSrYZrO alignment film production and LC molecular alignment were integrated through a one-step brush coating process. As the curing temperature increased, the LC molecule alignment of the LC cell improved, and the formation of a physical surface anisotropic structure due to the shear stress caused by the movement of the brush hairs on the coating surface led to uniform alignment of the LC molecules. Uniform and homogeneous LC molecular alignment was confirmed through polarizing optical microscopy and pretilt angle measurement. Through thermal oxidation using X-ray photoelectron spectroscopy, the TiSrYZrO thin film well formed of metal oxide was confirmed and verified to have excellent optical transparency. From these results, it is expected that a convenient LC molecular alignment method using brush hairs as an alternative to the rubbing process will be a viable next-generation technology.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.133-136
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• 1998

The scanning Maxwell-stress microscopy (SMM) is a dynamic noncontact electric force microscopy that allows simultaneous access to the electrical properties of molecular system such as surface potential, surface charge, dielectric constant and conductivity along with the topography. Here we report our recent results of its application to nanoscopic study of domain structures and electrical functionality in organic thin films prepared by the Langmuir-Blodgett technique.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.113-114
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• 2013

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging is a powerful technique for producing chemical images of small biomolecules (ex. metabolites, lipids, peptides) "as received" because of its high molecular specificity, high surface sensitivity, and submicron spatial resolution. In addition, matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) imaging is an essential technique for producing chemical images of large biomolecules (ex. genes and proteins). For this talk, we will show that label-free mass imaging technique can be a platform technology for biomedical studies such as early detection/diagnostics, accurate histologic diagnosis, prediction of clinical outcome, stem cell therapy, biosensors, nanomedicine and drug screening [1-7].

• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.37-42
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• 1993

Surface proteins of Trichomonqs unginnlis (T vqsinalis) were analyzed to study the antigenic variation. The surface proteins of protozoa were labelled by N- hydrokysuccinimide-biotin (NHS-biotins, the NHS-biotin-labelled proteins were immunoprecipitated with rabbit antiserum to purifjr the antigenic fractions and analysed by SDS-PAGE plus electroblotting. The results obtained in this study were as follows; Biotinylated T. uaginalis-proteins obtained from intact cell and cells disrupted prior to labelling were detected by antibiotin-peroxidase in Western blots. Labelled proteins were immunoprecipitated by T. vcqinalis-immunized rabbit serum and the six bands with, the molecular weights of 46, 60, 68, 90, 130 and 220 kDa were identified as having antigenicity. T unginalis HY-1,HY-15 and ATCC 50148 were immunoprecipitated by immune rabbit serum after biotinylation and there were no difference from antigenic bands among these strains by this tehchnique. In conclusion with the results obtained in the present study, it was assumed that surface proteins of T vaqinclis were labelled by biotinylation and the six labelled bands at 46, 60, 68, 90, 130 and 220 kDa in their molecular weight were identified as having antigenicity by immunoprecipitation (IPI and this biotinylation-IP technique may be used for further study of surface antigen of T vaginalis.

• Journal of Mechanical Science and Technology
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• v.16 no.11
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• pp.1440-1447
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• 2002

Adhesion of a hemispherical tip to the flat surface in nano-structures is simulated using the molecular dynamics technique. The tip and plates are modeled with the Lennard-Jones molecules. The simulation focuses on the deformation of the tip. Detailed descriptions on the evolution of interaction force, the energy dissipation due to adhesion hysteresis, the forma- tion-growth-breakage of adhesive junction as well as the evolution of molecular distribution during the process are presented. The effects of the tip size, the maximum tip approach, the tip temperature, and the affinity between the tip and the mating plate are also discussed.

• Transactions of Materials Processing
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• v.14 no.4 s.76
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• pp.319-326
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• 2005

In this study, the nano-deformation behavior of semi-solid Al-Si alloy was investigated using a molecular dynamics simulation as a part of the research on the surface crack behavior in thixoformed automobile parts. The microstructure of the grain-size controlled Al-Si alloy consists of primary and eutectic regions. In eutectic regions the crack initiation begins with initial fracture of the eutectic silicon particles and inside other intermetallic phases. Nano-deformation characteristics in the eutectic and primary phase of the grain-size controlled Al-Si alloy were investigated through the molecular dynamics simulation. The primary phase was assumed to be single crystal aluminum. It was shown that the vacancy occurred at the zone where silicon molecules were.

• Journal of the Semiconductor & Display Technology
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• v.12 no.1
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• pp.61-65
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• 2013

We investigated the wearable dynamics of diamond spherical abrasive during the substrate surface polishing under the pad compression via classical molecular dynamics modeling. We performed three-dimensional molecular dynamics simulations using the Morse potential functions for the copper substrate and the Tersoff potential function for the diamond abrasive. The pad hardness had a big impact on the wearable dynamics of the abrasive. The moving speed of the abrasive decreased with increasing hardness of the pad. As the hardness decreased, the abrasive was indented into the pad and then the sliding motion of the abrasive was increased. So the pad hardness was greatly influenced on the slide-to-roll ratio as well as the wearable rate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.323-326
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• 2000

In this study, we used Brewster-Angle Microscope(BAM) to study on the molecular orientation of monolayer on the water surface. The behaviors of molecules on three different subphase have been observed. Reproducible $\pi$-A isotherm have been obtained only on information about phase transition by molecular area. BAM facilitates the observation of morphology by optical anisotropy and thickness in monolayer and multilayers as BAM is shown to be sensitive to anisotropy of film. Every transition was found by BAM technique, either as a dramatic change in degree of contrast or as a sudden alteration of molecular action and $\pi$-A isotherm.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.4
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• pp.28-35
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• 2004

Stimulated by novel phenomena observed in molecular aggregates, recent developments in engineering fields of microscopic scales are creating tremendous opportunities for future nanotechnology-based applications. Investigation in the field involves sub-nanosecond or sub-micrometer interactions between extremely small systems, but researches, to date in these physical extremes have been quite limited. Here, we shed light on some of nanoscale phenomena using molecular dynamics simulation: visualization of various phenomena of nanoscales and exploration of size-dependent mechanical properties.

• Journal of the Korean Graphic Arts Communication Society
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• v.19 no.1
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• pp.64-74
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• 2001

This study is to find the effect of the molecular weight distribution of components on the freeness and physical properties of paper by observing the change of properties according the modification of fibers by using production technology and process technology together to develop additives which can effectively control according to the purpose of paper-making process and by combining low molecular weight cellulase (below MW 20,000; CMC activity 400 unit) with different enzyme's molecular weight and activity and high molecular weight cellulase(MW 20,000∼80,000;CMC activity 90,000 unit) and then process them in Sw-BKP(Softwood Bleached Kraft Pulp) and Hw-BKP(Hardwood Bleached Kraft Pulp) and Cotton Linter Pulp and OCC(Old Corrugated Container) with different properties of pore of surface of fibers respectively, since it is judged that making the appropriate composition ratio of components is necessary in consideration of the properties of fibers and paper-making process.