• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 봄 학술발표회 논문집
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• pp.52-55
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• 2003

Poly (ethylene 2, 6-naphthalate) (PEN) has been used for a high performance engineering plastics such as fiber, film, and packaging, because of excellent physical properties and outstanding gas barrier characteristics [1-2]. However, the application of PEN is limited because PEN exhibits a relatively high melt viscosity. Recently, many researches for organic/inorganic composites by applying nano-particles to the polymer matrix have been carried out [3], and the nano-particles exhibited greatly improved mechanical and rheological properties [4]. (omitted)

• Carbon letters
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• 제6권4호
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• pp.248-254
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• 2005

Silver impregnated activated carbon fibers were post-modified using hydrochloric acid. Adsorption behaviors, SEM morphologies, and functional groups for the silver impregnated ACFs were compared with those of post-modified ACFs. Adsorption isotherms were used to characterize $S_{BET}$, the pore structure and volume of silver-activated carbon fibers (ACFs) before and after acid post-treatment. In order to the reveal the causes of the differences surface states after the samples were washed with hydrochloric acid, outer surface and pore structure were investigated by SEM. And the type and quality of various functional groups were studied from FT-IR spectra and Boehm titration method. Finally, the quantitative properties in silver contents were also examined by EDX spectra.

• 한국군사과학기술학회지
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• 제12권6호
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• pp.739-749
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• 2009

Ever since gold was found, this element has fascinated human beings. It is stable in air, and is illuminating for several thousands years without changing its colors. Nanoparticles are the basic nanommaterials, and, particularly gold nanoparticles show unique properties which are not shown in bulk states. Scientists are trying to apply these new properties to catalysts, bioscience, optics, etc. Judging from the current research activities, one can envisage that gold nanoparticles can play a major role in opening a new era in diagnoses and treatment of diseases like cancers. However to apply the nanoparticles one must modify the surface of the nanoparticles in order to give the materials certain functionalities. It certainly is worth to review the current research status and challenges in the area of functional gold nanoparticles.

• Carbon letters
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• 제9권2호
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• pp.137-144
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• 2008

The commercial activated carbons are typically prepared by activation from coconut shell char or coal char containing lots of inorganic impurities. They also have pore structure and pore size distribution depending on nanostructure of precursor materials. In this study, two types of commercial activated carbons were applied for EDLC electrode by removing impurities with acid treatments, and controlling pore size distribution and contents of functional group with heat treatment. The effect of the surface functional groups on electrochemical performance of the activated carbon electrodes was investigated. The initial gravimetric and volumetric capacitance of coconut based activated carbon electrode which was acid treated by $HNO_3$ and then heat treated at $800^{\circ}C$ were 90 F/g and 42 F/cc respectively showing 94% of charge-discharge efficiency. Such a good electrochemical performance can be possibly applied to the medium capacitance of EDLC.

• 대한화학회지
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• 제64권2호
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• pp.61-66
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• 2020

In this study, we investigate the structural and electronic properties of copper oxide clusters, Cu_nO_n (n = 9 - 15). To find the lowest energy structures of copper oxide clusters, we use ReaxFF and density functional theory calculations. We calculate many initial copper oxide clusters using ReaxFF quickly. Then we calculate the lowest energy structures of copper oxide clusters using B3LYP/LANL2DZ model chemistry. We examine the atomization energies per atom, average bond angles, Bader charges, ionization potentials, and electronic affinities of copper oxide clusters. In addition, the second difference in energies is investigated for relative energies of copper oxide clusters.

• 한국식품영양과학회지
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• 제27권1호
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• pp.93-101
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• 1998

In order to improve the functional properties of several fish meat extracts as an alternate protein source, theri basic plastein reactions were evaluated. The UV absorption at 270 and 290 nm indicated that plasteins had higher amount of hydrophobic peptide or amino acid than the fish meat extracts. The water solubilities of the extracts were reduced at acidic pH. Values for the emulsifying capacity of the extracts and plasteins were over 30% although the latter showed the higher ones than the former. The osmolalities of the extracts at 1.0% concentration were 39(loach), 33(bastard halibut), 30(jacopever) and 24(crucan carp) milliosmole. Generally the slightly higher osmolalities were noted in the plasteins to be compared with the extracts. Both the extracts and plasteins exhibited a higher antioxidative effect than tocopherol. The hydrophobic amino acid which had been introduced at plastein reaction attributed the stronger antionxidative effect of its product than the extracts.

• 한국세라믹학회지
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• 제40권9호
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• pp.819-826
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• 2003

This article is concerned with the overview of activated carbons as electrode materials in electric double-layer capacitors. Firstly, this article introduced various types of activated carbons with their precursors and manufacturing conditions which can be divided into two main steps of the carbonization and activation processes. Secondly, the present article gave the detailed discussion about the porous structures and examined previous works on the electrochemical behaviors of activated carbons in relation to their porous structures, along with our recent works. Finally, this article characterized the surface oxygen functional groups and presented their influence on the electrochemical properties of activated carbons by reviewing our recent results.

• Transactions on Electrical and Electronic Materials
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• 제17권1호
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• pp.29-32
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• 2016

Using the various exchange-correlation functionals, such as LDA, GGA-PBE, GGA-PBEsol and GGA-AM05 functionals, first principle studies were conducted to determine the structures of paraelectric and ferroelectric PbTiO₃. Based on the structures determined by the various functionals, the piezoelectric properties of PbTiO₃ are predicted under the density-functional perturbation theory (DFPT). The present prediction with the various GGA functionals are closer to the experimental findings compared to the LDA values. The present DFT calculations using the GGA-PBEsol functional estimate the experimental data more reasonably than the conventional LDA and GGA fucntionals. The GGA-AM05 functional also predicts the experimental data as well as the GGA-PBEsol. The piezoelectric tensor calculated with PBEsol is relatively insensitive to pressure.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1289-1293
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• 2008

Fresh egg yolk (EY) was enzymatically modified using phospholipase $A_2$ ($PLA_2$) to produce an enzymatically modified-egg yolk powder (EM-EYP). The EM-EYP offered significantly higher emulsifying activity, emulsion stability, protein solubility, and mayonnaise stability than the control EYP. By employing $PLA_2$ in the enzymatic modification process, structural changes occurred in the phospholipids and lipoproteins of the yolk, and cleavage of apo-high density lipoprotein (HDL) components (Mw 105 kDa) was detected by sodium dodecyl sulfate-polyaerylamide gel electrophoresis (SDS-PAGE). Based on its functional properties, EM-EYP has great potential as a replacement for fresh EY in the production of processed food products such as mayonnaise.

• Composites Research
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• 제34권2호
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• pp.96-100
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• 2021

The lightweight industry continuously demands reliable near-net-shape fabrication where the preform just out-of-machine is close to the final shape. In this study, different half-finished preforms are made π-beams. Then the preforms are unfolded to make a 3D shape with integrated structure of fibers, providing easier handling in the further processing of composites. Several 3D textile preforms are made using weaving technique and are examined after resin infusion for mechanical properties such as inter-laminar shear strength, compressive strength and tensile strength. Considering that the time and labor are important parameters in modern production, 3D weaving technique reduces the manufacturing steps and therefore the costs, such as hand-lay up of textile layers, cutting, and converting into preform shape. Hence this 3D weaving technique offers many possibilities for new applications with efficient composite production.