• 한국염색가공학회지
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• 제24권2호
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• pp.113-120
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• 2012

Jacquard floor covering could be prepared from low-melting/regular sheath-core hybrid polyester, where the fiber is dyed in yarn state. With regard that the expected high shrinkage of the hybrid polyester in water makes problems in yarn dyeing, low-temperature dyeing properties of the hybrid polyester were studied. The rate of shrinkage of low-melting hybrid polyester exceeds 9% in hot water above $90^{\circ}C$, at such condition, cheese yarn dyeing is very difficult. Although disperse dyes exhaust in a relatively high speed on low-melting hybrid polyester, diffusion of these dyes to the core regular polyester was extremely slow under $90^{\circ}C$. Foron Blue E-BL 150, an anthraquinone E-type disperse dye, showed appreciable diffusion after 48hrs dyeing at $90^{\circ}C$. The fastness to rubbing and drycleaning were improved by one grade after reduction cleaning.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.97.2-97.2
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• 2011

Pt-Ru and Pt-Ni bimetallic catalysts were prepared and tested for heavy hydrocarbon reforming. Metals were supported on CGO($Ce_{0.8}Gd_{0.2}O_{2.0-x}$) by incipient wetness method. The prepared catalysts were characterized by Temperature programmed reduction(TPR). Oxidative steam reforming of n-dodecane was conducted to compare the activity of the catalysts. The reforming temperature was varied from $500^{\circ}C$ to $800^{\circ}C$ at fixed $O_2$/C of 0.3, $H_2O$/C of 3.0 and GHSV of 5,000/h.Reduction peaks of metal oxide, surface CGO and bulk CGO were detected. Reduction temperature of metal oxide decreased over the bi-metallic catalysts. It is considered that interaction between metals leads to decrease interaction between metal and oxygen. On the other hands, reduction temperatures of surface CGO were dectected in the order of Pt-Ru > Pt-Ni > Pt. low reduction temperatures of surface CGO indicates the low activation energy for oxygen ion conduction to metal. Oxygen ion conduction is known as de-coking mechanism of ionic conducting supports such as CGO. In activity test, fuel conversion was in the same order of Pt-Ru > Pt-Ni > Pt. Especially, 100% of fuel conversion was obtained over Pt-Ru catalysts at $500^{\circ}C$.

• Applied Science and Convergence Technology
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• 제24권6호
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• pp.262-267
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• 2015

We demonstrate the growth of single-walled carbon nanotubes (SWNTs) using ethylene-based chemical vapor deposition (CVD) and ferritin-induced catalytic particles toward growth temperature reduction. We first optimized the gas composition of $H_2$ and $C_2H_4$ at 500 and 30 sccm, respectively. On a planar $SiO_2$ substrate, high density SWNTs were grown at a minimum temperature of $760^{\circ}C$. In the case of growth using nanoporous templates, many suspended SWNTs were also observed from the samples grown at $760^{\circ}C$; low values of $I_D/I_G$ in the Raman spectra were also obtained. This means that the temperature of $760^{\circ}C$ is sufficient for SWNT growth in ethylene-based CVD and that ethylene is more effective that methane for low temperature growth. Our results provide a recipe for low temperature growth of SWNT; such growth is crucial for SWNT-based applications.

• 청정기술
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• 제2권1호
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• pp.60-68
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• 1996

고정층 반응기에서 망간광석을 이용하여 저농도의 일산화탄소 산화제어반응에 대하여 고찰하였다. 고려된 실험변수는 일산화탄소 농도 (500ppm~10000ppm), 산소 농도(500ppm~99.8%)와 촉매의 온도($50{\sim}750^{\circ}C$)이다. 또한 망간광석의 특성은 Thermogravimetric Analysis(TGA), 일산화탄소에 의한 환원, Temperature Programmed Reduction(TPR)실험을 이용하여 규명하였다. 망간광석의 일산화탄소 산화력은 순수이산화망간에 비해서 단위 면적당 높은 산화력과 $750^{\circ}C$까지 가열된 후에도 산화력이 유지될 수 있는 안정된 촉매작용을 보였다. Temperature Programmed Desorption(TPD), TPR 실험과 TG 등의 분석결과 산소의 농도가 낮거나 무산소하에서 망간광석의 격자내 산소가 쉽게 제공될 수 있음을 알 수 있었다. 일산화탄소의 농도가 500~3500ppm일 때 일산화탄소의 반응차수는 0.701이며 3500~10000ppm구간에서 일산화탄소의 농도에 무관한 0차 반응이었다.

• 한국건축시공학회지
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• 제16권1호
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• pp.1-7
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• 2016

본 연구에서는 $-5^{\circ}C$이하에서도 가열 양생이 없이 수화 반응시 수화열이 높게 발생되는 환원슬래그를 시멘트 분체와 치환사용 하여 영하의 온도에서도 콘크리트의 자체 발열로 인해 압축강도를 재령 3일 이내 5MPa를 발현시켜 초기동해를 방지시키는 것이 최종 연구의 목적이며 이에 대하여 환원슬래그의 물리적 특성 평가와 열적 특성 평가를 실시한 결과 환원슬래그는 높은 수화열을 발생시키기 때문에 저온에서도 압축강도 발현이 우수함을 알 수 있었다. 이는 환원 슬래그의 성분 중 $C_{12}A_7$과 $C_3A$에 의해 수화열이 높게 발생됨 저온에서도 압축강도가 발현되는 것으로 나타났다. 하지만 환원슬래그 단독 치환하였을 경우 $SO_3$함량 부족으로 급결이 발생하는 것을 알 수 있었다. 급결을 방지하기 위해서는 석고의 사용이 필수적으로 사용되어야 한다. 따라서 본 연구 결과 환원슬래그와 석고를 3성분계로 사용하였을 경우 저온에서도 재령 3일에서 5MPa 압축강도를 나타나는 것으로 보아 저온에서도 콘크리트의 초기동해를 방지할 수 있을 것으로 판단된다.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.473-478
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• 2008

망간황화물이 NO의 선택적 촉매 환원에 미치는 영향을 반응성 및 속도론적평가와 TPR(Temperature Programmed Reduction), TGA분석을 통하여 고찰하였다. 망간산화물은 $200^{\circ}C$ 이하의 저온에서 우수한 질소산화물 전환을 보였으나, 망간황화물의 경우 황화정도에 따라 질소산화물 전환은 고온으로 전이하였다. 또한 질소산화물 전환율도 황화정도에 따라 감소하였다. TPR 실험결과 망간산화물들은 $160^{\circ}C$ 이하의 낮은 온도에서 환원이 시작되었으나 망간황화물은 $280^{\circ}C$ 이상의 온도에서 환원이 시작되었다. TPR 실험을 통한 환원 시작온도는 촉매의SCR 시작 온도와 관련이 있는 것으로 판단된다. 망간황화물의 활성화에너지는 다른 촉매에 비해 낮게 나타났으나 pre-exponential 상수 크기가 다른 촉매에 비해 1/1000배 만큼 작아 NO에 대한 활성이 낮게 나타났다. 천연망간광석은 함유된 다양한 금속산화물의 영향으로 순수한 망간산화물보다 낮은 온도에서 재생되었다.

• Environmental Engineering Research
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• 제10권5호
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• pp.239-246
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• 2005

The effect of Pt addition over $V_2O_5-WO_3/TiO_2$ catalyst supported on PRO-66 was investigated for NO reduction in order to develop the catalytic filter working at low temperature. Catalytic filters, $Pt-V_2O_5-WO_3/TiO_2/PRD$, were prepared by co-impregnation of Pt, V, and W precursors on $TiO_2$-coated ceramic filter named PRD (PRD-66). Titania was coated onto the pore surface of the ceramic filter using a vacuum aided-dip coating method. The Pt-loaded catalytic filter shifted the optimum working temperature from $260-320^{\circ}C$(for the catalytic filter without Pt addition) to $190-240^{\circ}C$, reducing 700 ppm NO to achieve the $N_x$ slip concentration($N_x\;=\;NO+N_2O+NO_2+NH_3$) less than 20 ppm at the face velocity of 2 cm/s. $Pt-V_2O_5-WO_3/TiO_2$ supported on PRD showed the similar catalytic activity for NO reduction with that supported on SiC filter as reported in a previous study, which implies the ceramic filter itself has no considerable interaction for the catalytic activity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.451-454
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• 2001

The ionic conductivity of cubic solid solutions in the system $Y_{2}O_{3}-ZrO_{2}$ prepared by SHS was examined. Conductivity-temperature data obtained at $1000^{\circ}C$ in atmosphere of low oxygen partial pressure ($10^{-40}$ atm) for $Y_{2}O_{3}-ZrO_{2}$ cubic solid solutions indicated that these materials could be reduced, the degree of reduction being related to the measuring electric field. At low impressed fields no reduction was observed. Thus, these conductivity data give a transference number for the oxygen ion in $Y_{2}O_{3}-ZrO_{2}$ cubic solid solutions greater than 0.99.

• 소성∙가공
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• 제25권5호
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• pp.306-312
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• 2016

Effects of manufacturing conditions, such as austenitizing temperature, patenting temperature and carbon content in steels, on mechanical properties, especially on reduction of area (RA), of hyper-eutectoid steel wires were investigated. RA increased and then decreased with transformation temperature. This was attributed to the presence of abnormal structures in steels transformed at low transformation temperatures and the occurrence of shear cracking during tensile testing of steels transformed at high transformation temperatures. The increase of austenitizing temperature resulted in the increased austenite grain size and consequently the decrease of RA. The decrease of RA with increasing the carbon content in steels was attributed to the increased fraction of cleavage fracture in tensile fractured surfaces.

• International Journal of Air-Conditioning and Refrigeration
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• 제14권4호
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• pp.147-155
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• 2006

The drag reduction (DR) and heat transfer efficiency reduction (ER) of non-ionic surfactant were investigated as a function of fluid velocity, temperature, and surfactant concentration. An experimental apparatus consisting of two temperature controlled water storage tanks, pumps, test specimen pipe and the piping network, two flow meters, two pressure gauges, a heat exchanger, and data logging system was built. From the experimental results, it was concluded that existing alkyl ammonium surfactant (CTAC Cethyl Trimethyl Ammonium Chloride) had DR of $0.6{\sim}0.8$ at $1,000{\sim}2,000ppm$ concentration with fluid temperature ranging between $50{\sim}60^{\circ}C$. However, the DR was very low when the fluid temperature was $70{\sim}80^{\circ}C$. The new amine oxide and betaine surfactant(SAOB Stearyl Amine Oxide + Betaine) had lower DR at fluid temperatures ranging between $50{\sim}60^{\circ}C$ compared with CTAC. However, with fluid temperature ranging between $70{\sim}80^{\circ}C$ the DR was $0.6{\sim}0.8$ when the concentration level was $1,000{\sim}2,000ppm$.