• 패션비즈니스
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• 제7권2호
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• pp.69-81
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• 2003

Among the various properties of textile fabrics, the moisture-related properties are important for the textile processes or the apparel comfort characteristics. Alkaline hydrolysis results in pitting on the surface of fibers and increases the amount of hydroxyl and carboxyl end groups of the PET molecules on the fiber surface. The purpose of this study is to investigate the moisture-related properties of PET fabrics treated with quaternary ammonium compound/alkaline solution. The wetting and wicking properties of the PET fabrics were measured using the following experiments: contact angle, surface free energy, work of adhesion, vertical wicking height, moisture regain, and frictional static voltage. It was concluded that by the alkaline hydrolysis process, surface hydrophilicity and reactivity were considerably improved especially at lower levels of weight loss% and that the pitting of the fiber surface resulted in at higher levels of weight loss% was disadvantageous in moisture-related properties of PET.

• 한국염색가공학회지
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• 제15권3호
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• pp.132-139
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• 2003

PTT[Poly(trimethylene terephthalate)] fibers was annealed by passing on the plate heater to illuminate the effects of annealing on the alkaline hydrolysis behavior properties with varying the treatment temperature for 0.5 second. The L010 and crystallinity were increased with increases in temperature. With the increases of the temperature, the dynamic viscoelastic behaviors were analyzed to be reduction in $T_{max}(tan\;\delta)$. The weight loss in alkaline solution was two times more rapid for the PTT annealed at $200^\circ{C}$ than the control samples. The kinetics of hydrolysis was confirmed that the hydrolysis of the PTT fibers in the alkaline solution was started from the surface of the fibers and selective to the amorphous region in continuation, on the basis of the results of the increase in crystallinity and the decrease in dye uptake at the initial stage of the hydrolysis.

• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.575-580
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• 2023

An electrode was prepared by dip-coating NiFe₂O₄ powder on stainless steel (SUS) support for the application in the alkaline water electrolysis. The prepared electrode was analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS), and was evaluated for the voltage properties with the change of current density in oxygen evolution reaction (OER) and hydrgen evolution reaction (HER) using 1, 3 and 7 M KOH solution. From the SEM and EDXS analysis, it was confirmed that the prepared electrode had NiFe₂O₄ on the SUS support. In OER and HER, the voltage in the 7 M KOH solution had a value of 1.35 and -1.90 V at 0.2 and -0.2 A/cm² of the current density, respectively. It was considered that the prepared electrode could be use as an electrode in the alkaline water electrolysis from the experimental results.

• 전기화학회지
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• 제15권2호
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• pp.90-94
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• 2012

We report nanostructure electrodes with $TiO_2$ as a core and carbon as a shell ($TiO_2$@C) for oxygen reduction in alkaline solution. The structure of core-shell electrodes is characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction method, and X-ray photoelectron microscopy. The electrochemical properties of the $TiO_2$@C electrodes are characterized using a potentiostat and compared with those of carbon supported Pt catalyst. In particular, the core-shell electrode with dominant pyridinic-N component exhibits an imporved electrocatalytic activity for oxygen reduction reaction in alkaline solution.

• Nuclear Engineering and Technology
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• 제45권1호
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• pp.67-72
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• 2013

Stress corrosion cracking (SCC) behaviors of Alloy 690 were studied in lead-containing aqueous alkaline solutions using the slow strain rate tension (SSRT) tests in 0.1M and 2.5M NaOH with and without PbO at $315^{\circ}C$. The side and fracture surfaces of the alloy were then examined using scanning electron microscopy after the SSRT test. Microstructure and composition of the surface oxide layer were analyzed by using a field emission transmission electron microscopy, equipped with an energy dispersive X-ray spectroscopy. Even though Alloy 690 was almost immune to SCC in 0.1M NaOH solution, irrespective of PbO addition, the SCC resistance of Alloy 690 decreased in a 2.5M NaOH solution and further decreased by the addition of PbO. Based on thermodynamic stability and solubility of oxide, high Cr of 30wt% in the Alloy 690 is favorable to SCC in mild alkaline and acidic solutions whereas the SCC resistance of high Cr Alloy 690 is weakened drastically in the strong alkaline solution where the oxide is not stable any longer and solubility is too high to form a passive oxide locally.

• Advances in concrete construction
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• 제5권4호
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• pp.345-358
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• 2017

This paper describes the experimental investigation carried out to develop geopolymer concrete using rice husk ash (RHA) along with alccofine. The study reports the fresh and hardened properties of the geopolymer concrete (GPC) activated using alkaline solution. GPC were prepared using different RHA content (350, 375 and $400kg/m^3$), the molarity of the NaOH (8, 12 and 16M). The specimens were cured at $27^{\circ}C$ and $90^{\circ}C$. GPC was activated using NaOH, $Na_2SiO_3$, and alccofine. Prepared GPC samples were tested for compressive and splitting tensile strengths after 3, 7 and 28 days. RHA was suitable to produce geopolymer concrete. Results indicate that behavior of GPC prepared with RHA is similar to fly ash based GPC. Workability and strength can be improved by incorporating the alccofine. Further, alccofine and heat curing improve the early age properties of the GPC. Heat curing is responsible for the initial polymerization of GPC which leads to high workability and improved mechanical properties of the GPC. High strength can be achieved by using the high concentration alkaline solution in terms of molarity and at elevated heat curing. Further, RHA based geopolymer concrete has tremendous potential as a substitute for ordinary concrete.

• 한국수산과학회지
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• 제19권6호
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• pp.537-546
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• 1986

고등어 유문수조직중에 분포하는 알칼리성단백질분해효소의 정제조건을 검토하고 염석, DEAE-Sephadex A-50 칼럼 크로마토그래피 및 Sephadex G-100 겔 여과에 의해 3종류의 알칼리성단백질분해효소의 분리${\cdot}$정제방법을 확립하였다. 유문수조직중에 분포하는 알칼리성단백질분해효소의 추출용매는 $1\%$ NaCl 용액이 가장 효과적이었다. 정제된 가칭 Enz, A, B 및 C의 각 알칼리성단백질분해효소는 전기영동적으로 균질함이 증명되었으며, 조효소에 비해 고유활성이 Enz. A는 34배, B는 53배 그리고 C는 37배로 각각 증가하였다. 각 효소의 수율은 조효소에 대해 $1.6\%,\;2.1\%$ 및 $1.5\%$였고, 총수율은 $5.2\%$였다.

• 한국표면공학회지
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• 제44권3호
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• pp.82-88
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• 2011

A uniform chromium-free conversion coating treated with an alkaline phosphate- permanganate solution was formed on the AZ 31 magnesium alloy. The effect of acid pickling on the morphology and on the corrosion resistance of the alkaline phosphate-permanganate conversion coating was investigated. The chemical composition and phase structure of conversion coating layer were determined via optical microscopy, SEM, EDS, XPS and XRD. Results show that the conversion coatings are relatively uniform and continuous, with thickness 1.8 to $2.4\;{\mu}m$. The alkaline phosphate-permanganate conversion coating was mainly composed of elements Mg, O, P, Al and Mn. The conversion-coated layers were stable compounds of magnesium oxide and spinel ($MgAl_2O_4$). These compounds were excellent inhibitors to corrosion. The electrochemical corrosion behaviors of coatings in 3.5 wt.% NaCl solutions were evaluated by electrochemical impedance spectroscopy, potentiodynamic polarization technique. EIS results showed a polarization resistance of $0.1\;k{\Omega}$ for the untreated Mg and $16\;k{\Omega}$ for the alkaline phosphate-permanganate conversion treatment sample, giving an improvement of about 160 times. The results of the electrochemical measurements demonstrated that the corrosion resistance of the AZ 31 magnesium alloy was improved by the alkaline phosphate-permanganate conversion treatment.

• 한국세라믹학회지
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• 제47권3호
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• pp.216-222
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• 2010

Portland cement has been restricted in applications to ecological area because of its environmental harmfulness and the $CO_2$ emission during a production process. Geopolymer materials attract some attention as an inorganic binder due to their superior mechanical and eco-friendly properties. In this study, geopolymer-based cement was prepared by using aluminosilicate minerals (flyash, meta-kaolin) with alkaline-activators and its compressive strength with concentration of alkaline-activators was investigated. Aluminosilicate-based geopolymers were obtained by mixing aluminosilicate minerals, alkaline solution (NaOH or KOH with different concentration) and water-glass under the vigorous stirring for 20 min. Compressive strength after curing at $30^{\circ}C$ for 3 days increased with the concentration of alkaline-activator due to the enhanced polymerization of the aluminosilicate materials and dense microstructure. Aluminosilicate-based geopolymer cement using KOH as an alkaline-activator showed high compressive strength compared with NaOH activator. In addition, geopolymer cement using fly-ash as a raw material showed higher compressive strength than that of meta-kaolin.

• 한국응용곤충학회지
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• 제27권4호
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• pp.211-218
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• 1988

담배거세미나방(Spodoptera litura: SI), 누에(Bombyx mori: Bm) 및 흰불나방(Hyphantria cunea : Hc)으로부터 분리된 핵다각체병 바이러스(nuclear polyhedrosis virus : NPV)의 다각체의 단백질의 특성과 그에 대한 alkaline protease의 영향을 SDS-PAGE 및 혈정학적 방법으로 분석했다. Alkaline protease를 부활화시킨 후 다가체 단백질을 SDS-PAGE한 결과, BmNPV의 경우 30kD, SINPV와 HcNPV는 31kD의 단일 major band 및 이것들의 종합체(polymer)인 57kD와 66kD의 minor band들이 관찰되었다. Alkaline protease의 부활화를 성략한 SI NPV 다각체를 알칼리 용액으로 시간 차이를 두고 처리한 후 SDS-PAGE한 결고, 알칼리 처리시간이 경과함에 따라서 alkaline protease활성에 의해 다각체 단백질이 일정한 pattern으로 저분자화됨이 뚜렷하였다. SINPV 와 BmNPV 다각체 단백질의 항체를 제조하여 SINPV, BmNPV및 HcNPV 다각체 단백질간의 혈정학적 상동성을 이중형역광산법과 Western blot으로 비교한 결과는 3종 모두에서 공통 antigenic determinants의 존재가 인정되었으며 major 다각체 단백질의 종합체 형성과 alkaline protease에 의한 분해를 확인했다.