• E2M - 전기 전자와 첨단 소재
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• 제10권2호
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• pp.113-118
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• 1997

For the amorphous F $e_{78}$ $B_{13}$S $i_{9-x}$G $e_{x}$ alloy, thermal analysis and measurements of the magnetic properties were carried out. As the content of Ge increased, the crystallization temperature was decreased and the Curie temperature was increased, and the tendencies were almost linear. The core loss of the amorphous alloy for x=1.7, field annealed at optimized condition, was 0.057 W/kg(l.0T, 60Hz), which was about 30% lower than that of no Ge added amorphous alloy (basic composition). Such a low core loss characteristics was thought to be caused by the lower coercive force and good squareness of B-H loop of the alloy.y.y.

• 한국대기환경학회지
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• 제26권1호
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• pp.1-9
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• 2010

In this study, the selective catalytic reduction of $NO_x$ with ammonia was carried out in a filter bag support reactor. The experiments were performed by powder type $MnO_x$ and $V_2O_5$/$TiO_2$ catalyst at low temperature between 130 and $250^{\circ}C$. Also, the effect of $SO_2$ and $H_2O$ on the NO conversion was investigated under our test conditions. The powder type catalysts were analyzed by X-ray photoelectron spectrum (XPS), X-ray diffraction(XRD), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). It was observed that NO removal efficiency of the powder type $V_2O_5$/$TiO_2$ catalyst was 85% at low temperature($200^{\circ}C$) under presence of oxygen and that of $MnO_x$ was 50% at the same condition. The powder type $V_2O_5$/$TiO_2$ catalyst, in conclusion, was found to be available for SCR reaction in a filter bag support system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.423-423
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• 2008

One dimensional (1D) nanostructures, including nanowires, nanorods, nanobelts, and nanotubes, have been the focus of current research on nanotechnology because of their fundamental significance in chemistry, physics, materials science and engineering, and potential applications in nanoelectronics. We have synthesized Te-rich $Sb_xTe_{1-x}$ nanowires and nanotubes via thermal evaporation method under vapor-solid mechanism. The physical morphology and chemical composition of the fabricated nanowires and nanotubes were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX).

• 한국자동차공학회논문집
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• 제15권3호
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• pp.183-188
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• 2007

Recently, diesel engine has been frequently applied to RV, SUV and light duty truck due to the good fuel economy and high thermal efficiency. $NO_x$ and PM, environmental pollution materials are basically produced in diesel combustion process. The most important target in diesel engine research is the development of system to reduce the emissions of $NO_x$ and PM. Cooled EGR system is an effective method for the reduction of $NO_x$ emission and PM emission from a diesel engine and EGR cooler is the key component of the system. This study investigates the EGR cooler of oval gas tubes compared with the EGR cooler of shell & tubes to verify the heat exchange efficiency of cooler by means of engine dynamometer tests, rig performance tests and numerical analyses.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2375-2380
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• 2013

Two metal-organic frameworks based on the connectivity co-effect between rigid benzenedicarboxylic acid and bridging ligand have been synthesized $[Zn_2(3-NO_2-bdc)_2(4,4'-bpy)_2H_2O]_n$ (1), $[Co(3-NO_2-bdc)(4,4'-bpy)H_2O]_n$ (2) (where $3-NO_2-bdcH_2$ = 3-nitro-1,2-benzenedicarboxylic acid, 4,4'-bpy = 4,4'-bipyridine). The two novel complexes were characterized by IR spectrum, elemental analysis, fluorescent properties, thermogravimetric analysis, single-crystal X-ray diffraction and powder X-ray diffraction (PXRD). X-ray structure analysis reveals that 1 and 2 are two-dimensional (2D) network structures. Complex 1 and complex 2 belong to triclinic crystal with P-1 space group. The luminescence measurements reveal that two complexes exhibit good fluorescent emissions in the solid state at room temperature. Also, thermal decomposition process and powder X-ray diffraction of complexes were investigated.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.311-312
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• 2005

By using 45$^{\circ}$ obliqued evaporation method with electron beam system, uniformly vertical liquid crystal (LC) alignment was achieved. And a high pretilt angles of about 2.5$^{\circ}$ were measured. Also, it was verified that there are no variations of pretilt angle as a function of $SiO_x$ thin film thickness 20nm and 50nm. A good LC alignment states were observed at annealing temperature of 250$^{\circ}C$. The high pretilt angle and the good thermal stability of LC alignment by 45$^{\circ}$ obliqued electron beam evaporation method on the $SiO_x$ thin film can be achieved.

• 한국분무공학회지
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• 제25권3호
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• pp.132-138
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• 2020

N₂O is hazardous atmosphere pollution matter which can damage the ozone layer and cause green house effect. There are many other nitrogen oxide emission control but N₂O has no its particular method. Preventing further environmental pollution and global warming, it is essential to control N₂O emission from industrial machines. In this study, the thermal decomposition experiment of N₂O gas mixture is conducted by using cylindrical reactor to figure out N₂O reduction and NO formation. And CHEMKIN calculation is conducted to figure out reaction rate and mechanism. Residence time of the N₂O gas in the reactor is set as experimental variable to imitate real SNCR system. As a result, most of the nitrogen components are converted into N2. Reaction rate of the N₂O gas decreases with N₂O emitted concentration. At 800℃ and 900℃, N₂O reduction variance and NO concentration are increased with residence time and temperature. However, at 1000℃, N₂O reduction variance and NO concentration are deceased in 40s due to forward reaction rate diminished and reverse reaction rate appeared.

• Radiation Oncology Journal
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• 제4권2호
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• pp.115-128
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• 1986

온열요법은 암치료에 있어서 방사선과 병용하였을 때 상호보완 작용을 하여 방사선에 저항성이 높은 세포주기의 S-기에 민감하게 작용하며 세포의 준치사손상의 회복을 저지시킴으로써 방사선의 효과를 상승시킬 수 있다. 저자는 100Watt, 2450MHz의 마이크로파 온열기구를 제작하고 조직등가인 판톰을 이용하여 예비측정과 방열조사 조건 및 방법을 계획한 후 생물학적 반응을 관찰하기 위하여 흰쥐 102마리를 이용하여 온열요법, X-선조사 (6Gy-15Gy) 및 선 조사와 온열요법을 병행하여 직장과 방광의 조직학적 소견을 관찰하여 다음과 같은 결론을 얻었다. 1) 100Watt, 2450MHz의 소형마이코로파 온열발생장치로서 조직을 $40{\sim}50^{\circ}C$로 유지하여 1시간 이상 가열할 수 있었다. 2) 조직온열분포는 깊이 3cm, 직명 2-10cm의 넓이에 $40{\sim}44^{\circ}C$의 온도분포를 계속 유지할 수 있었다. 3) 온열요법 단독으로는 직장의 점막하층의 부종을 볼 수 있었으나 방광의 조직학적 변화는 볼 수 없었다. 4) 점막상피괴사는 직장에 X-선조사 6Gy의 15일군에서, 방광에 8Gy의 15일군에서 각각 나타나기 시작하였으며, 근층괴사는 직장에 X-선조사 8Gy의 15일군에서, 방광에 10Gy의 60일군에서 각각 나타났다. 5) X-선조사와 온열요법병행군에서 직장과 방광의 조직학적변화 (점막과 근층의 괴사)를 관찰하여 열증강율은 1.0으로 증가되지 않음으로서 직장과 방광의 내용선량의 변화가 없음을 시사하였다.

• 대한기계학회논문집B
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• 제35권7호
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• pp.735-742
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• 2011

인체에 유해한 질소산화물($NO_x$)의 생성을 억제하면서 열효율을 높일 수 있는 새로운 버너의 개념으로 촉매 버너가 제안되었고 본 연구에서는 대표적인 에너지 다소비 설비인 건조기에 사용하기 위한 촉매버너를 개발하였다. 산업용 건조기에 활용하기 위해 촉매버너는 평평한 매트 형태로 제작되어 열전달 면적을 극대화하였고 밀폐 공간인 건조실에 활용하기 위하여 예혼합 연소방식을 적용하였다. 새로 개발된 촉매 버너를 산업용 건조기에 적용하여 실험한 결과 열에너지가 원적외선 형태로 공급되어 감율건조 영역에서 식품과 같은 유기물을 효과적으로 건조할 수 있음을 확인하였다. 또한 건조기의 열효율은 건조속도보다 피건조물의 함수율에 보다 큰 상관관계를 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제18권12호
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• pp.1249-1256
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• 1997

Single phase La1-xSrxCoO3 (x≤0.2) was synthesized as a uniform sized 100 nm particulates with relatively high surface area of 20-30 m2/g, at low temperature (≥600 ℃), from a polymeric gel precursors prepared by using poly(vinyl alcohol) as homogenizer. No minor phase developed during the crystallization when polymer/metal mole ratio was higher than 3. As the polymer/metal mole ratio was raised in the gel, the amount of carbonaceous residues in the amorphous solid precursor prepared by heating the gel at 300 ℃ increased. Most of the residues were eliminated by exothermic thermal decomposition around 400 ℃. The amount of residual carbon (less than 1%) left in the crystalline La1-xSrxCoO3 decreased as more polymer was used, eliminating detrimental effect which might be posed by using large amount of organic homogenizer. The crystal structure of La1-xSrxCoO3 synthesized at temperature lower than 800 ℃ was observed to be shifted from rhombohedral to more symmetric cubic. The structure shifted back to rhombohedral as the cubic sample was annealed at 1000 ℃.