• Geomechanics and Engineering
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• v.20 no.6
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• pp.505-516
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• 2020

In recent years, Nano-technology significantly invaded the field of Geotechnical engineering, particularly in soil stabilisation techniques. Stabilisation of weak soil is envisioned to modify various soil characteristics by the addition of natural or synthetic materials into the virgin soil. In the present study, laboratory experiments were executed to investigate the influence of nano-silica particles in the consistency limits, compressive strength of the soft clay blended with cement. The results revealed that the high compressibility behaviour of soft clay modified to medium-stiff condition with fewer dosages of cement and nano-silica. The mechanism behind the strength development is verified with the previous researches as well as from Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction test (XRD) and Scanning Electron Microscopy (SEM) analysis. Based on the results, the presence of nano-silica in soft clay blended with cement has a positive effect on the behaviour of soil. This technique proves to be very economical and less detrimental to the environment.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.50-50
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• 2011

The aluminum nitride films were prepared by RF magnetron sputtering using an AlN ceramic target. The crystallinity, grain size, Al-N bonding and thermal conductivity were investigated in dependence on the plasma power densities (4.93, 7.40, 9.87 W/$cm^2$) during sputtering. High thermal conductivity is important properties of A1N passivation layer for functioning properly in thermal inkjet printhead. The crytallinity, grain size, Al-N bonding formation and chemical composition were observed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), respectively. The AlN thin film was changed from amorphous to crystalline as the power density was increased, and the largest grain size appeared at medium power density. The near stoichiometry Al-N bonding ratio was acquired at medium power density. So, we know that the AlN thin film had better thermal conductivity with crystalline phase and near stoichometry Al-N bonding ratio at 7.40 W/$cm^2$ power density.

• Fibers and Polymers
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• v.7 no.3
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• pp.235-240
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• 2006

Polyacrylonitrile (PAN) fiber was grafted with casein after alkaline hydrolysis and chlorination reactions of the original fiber. The structures and morphologies of the casein grafted fiber were characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), and scanning electron microscope (SEM). Moisture absorption, specific electric resistance, water retention value, and mechanical properties were also investigated. The results showed that casein was grafted onto the surface of the PAN fiber and the grafted PAN fiber presented better hygroscopicity compared with the untreated fiber. With proper tensile strength, the modified fiber could still meet the requirement for wearing. A mechanism was proposed to explain the deposit of casein on the synthetic acrylic fiber.

• Korean Membrane Journal
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• v.1 no.1
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• pp.86-92
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• 1999

The nanofiltration (NF) membranes based on poly(vinyl alcohol) (PVA) and sodium alginate (SA) were prespared. Homogeneous PVA/SA blend membranes were prepared by casting a PVA/SA (95/5 in wi%) mixture solution on an acryl plate followed by drying at a room temperature and by cros-slinking with glutaraldehyde (GA) for 20 minutes PVA/SA blend composite membranes were also prepared by coating a PVA/SA (95/5 in wi%) mixture solution on microporous polysulfone(PSF) supports. The PVA/SA active layer of the composite membrane was crosslinked at room temperature by using an membranes were characterized with a scanning electron microscopy (SEM) a fourier transform infrared spectroscopy (FTIR) and permeation tests. The permeation properties of the composite membrane were as follows: 1.3{{{{ {m }^{2 } }}}}/{{{{ {m }^{2 } }}}}day of flux and >95% of rejection at 200 psi for a 1000 ppm PEG600 solution.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.34-46
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• 2002

Si-O-C-H films with a low dielectric constant were deposited on a p-type Si(100) substrate using a mixture gases of the bis-trimethylsilyl-methane (BTMSM) and oxygen by an inductively coupled plasma chemical vapor deposition (ICPCYD). High density plasma of about $~10^{12}\textrm{cm}^{-3}$ is obtained at low pressure (<400 mTorr) with rf power of about 300W in ICPCVD where the BTMSM and $O_2$ gases are fully dissociated. Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS) spectra show that the film has $Si-CH_3$ and OH-related bonds. The void within films is formed due to $Si-CH_3$ and OH-related bonds after annealing at $500^{\circ}C$ for the as-deposition samples. The lowest relative dielectric constant of annealed film at $500^{\circ}C$ is about 2.1.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2680-2686
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• 2009

The synthesis of a novel superabsorbent hydrogel with natural hybrid backbone via graft copolymerization of acrylamide (AAm) onto kappa-carrageenan (kC, as a polysaccharide) and gelatin (as a protein) under classic thermal conditions is described. The Taguchi method as a strong experimental design tool was used for synthesis optimization. A series of hydrogels were synthesized by proposed conditions of Qualitek-4 Software. Considering the results of 9 trials according to analysis of variance (ANOVA), optimum conditions were proposed. The swelling behavior of optimum hydrogel was measured in various solutions with pH values ranging from 1 to 13. In addition, swelling kinetics, swelling in various organic solvents, various salt solutions and On–Off switching behavior were investigated. The hydrogel formation was confirmed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetrical analysis (TGA). Surface morphology of the synthesized hydrogels was assessed by scanning electron microscope (SEM).

• Macromolecular Research
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• v.11 no.5
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• pp.311-316
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• 2003

The kinetics of photoinitiated polymerization of dimethacrylate macromonomers have been studied to determine the diffusion-controlled reaction parameters using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). A predicted kinetic rate expression with a diffusion control factor was employed to estimate an effective rate constant and to define the reaction-controlled and diffusion-controlled regimes in the photopolymerization. An effective rate constant, k$_{e}$, can be obtained from the predicted kinetic rate expression. At the earlier stages of polymerization, the average values of kinetic rate constants do not vary during the reaction time. As the reaction conversion, $\alpha$, reaches the critical conversion, $\alpha$$_{c}$, in the predicted kinetic expression, the reaction becomes to be controlled by diffusion due to the restricted mobility of dimethacrylate macromonomers. A drop in value of effective rate constant causes a drastic decrease of reaction rate at the later stages of polymerization. By determining the effective rate constants, the reaction-controlled and diffusion-controlled regimes were properly defined even in the photopolymerization reaction system.m.m.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.35-38
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• 1999

Nanofiltration (NF) composite membranes based of poly (vinyl alcohol) (PVA) and sodium alginate (SA) were prepared by coating PVA/SA (95/5 in wt %) mixture solutions on the microporous polysulfone (PS) supports, followed by the crosslinking with glutaraldehyed. The composite membranes prepared were characterized with a scanning electron microscopy (SEM), a fourier transform infrared spectroscopy(FTIR), an elecrtokinetic analyzer (EKA) and permeation tests.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1868-1869
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• 2005

이 논문은 반도전 실리콘 고무 표면에 코로나 방전 처리하여 이종의 실리콘 고무와의 접착 특성을 나타낸 것이다. 반도전 실리콘 고무 표면 상태를 발수성 등급에 따른 분류와 FTIR(Fourier Transform Infrared Spectroscopy)를 사용하여 평가하였다. 표면 상태 변화에 따른 반도전 실리콘 고무의 접착 특성은 T-peel test로 접착강도를 시험하였다. 실험 결과 고에너지의 코로나 방전으로 반도전 실리콘 고무의 결합쇄가 절단되었고 이 부분에 산소가 결합되어 극성 관능기를 생성하여 표면을 산화시켰다. 이러한 표면 상태 변화에 따른 접착강도는 초기 상태일 때 보다 코로나 방전 처리 후 증가하는 것을 확인 할 수 있었다. 이 논문을 통하여 코로나 방전 처리는 이종 계면의 접착 특성을 향상시킬 수 있으며, 이종 계면에서 발생하는 절연 파괴 전압을 높여 전기절연 성능을 향상시키는데 도움이 될 것이다.

• Macromolecular Research
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• v.17 no.8
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• pp.585-590
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• 2009

The cure behaviors, dielectric characteristics and fracture toughness of diglycidylether of bisphenol-A (DGEBA)/poly(ethylene terephthalate) (PET) blend system were investigated. The degree of conversion for the DGEBA/PET blend system was measured using Fourier transform infrared (FTIR) spectroscopy. The cure kinetics were investigated by measuring the cure activation energies ($E_a$) with dynamic differential scanning calorimetry (DSC). The dielectric characteristic was examined by dielectric analysis (DEA). The mechanical properties were investigated by measuring the critical stress intensity factor ($K_{IC}$), critical strain energy release rate ($G_{IC}$), and impact strength test. As a result, DGEBAIPET was successfully blended. The Ea of the blend system was increased with increasing PET content to a maximum at 10 phr PET. The dielectric constant was decreased with increasing PET content. The mechanical properties of the blend system were also superior to those of the neat DGEBA. These results were attributed to the increased cross-linking density of the blend system, resulting from the interaction between the epoxy group of DGEBA and the carboxyl group of PET.