• 식물분류학회지
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• 제45권1호
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• pp.17-21
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• 2015

석송과 뱀톱속에 속하는 신종 긴다람쥐꼬리(H. jejuensis B.-Y. Sun & J. Lim.)를 기재하고 도해하였다. 긴다람쥐꼬리는 현재까지 H. integrifolia (Matsuda) B. Ollg. ex Z. Satou로 취급되어 왔으나 기부(base)에서 중간부까지 가장자리가 평행한 선상피침형의 잎, 잎의 중간부에서 상부까지 존재하는 미세한 치아상거치, 무성아의 정단은 예철두인 점에 의해 뚜렷이 구분되었다. 학명의 종소명은 신종의 생육지가 제주도인 점을 고려하여 'jejuensis'로 신칭하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.190-190
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• 2005

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.191-191
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• 2005

• 식물분류학회지
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• 제45권4호
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• pp.299-305
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• 2015

Huperzia lucidula (Michaux) Trevis.의 동북아시아 집단 및 북미 집단을 대상으로 외부형태와 포자형태를 비교한 결과 잎의 형태, 엽연부, 잎에서의 기공의 분포 및 포자의 형태에 있어서 뚜렷히 구분되었다. 따라서, 동북아시아 집단을 북미 지역의 H. lucidula와는 독립된 종 H. asiatica (Ching) B.-Y. Sun and J. Lim으로 분리, 승격하였다. 또한, H. serrata (Thunb.) Trevis.와 동일 종 또는 종내 분류군으로 인식되어 오던 H. javanica (Sw.) C. Yang은 영양엽에서 엽병의 발달 유무, 엽연 거치의 수 그리고 무성아가지의 중앙 열편 모양으로 별개의 종으로 처리하는 견해를 지지하였다.

• 한국수소및신에너지학회논문집
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• 제19권1호
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• pp.35-40
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• 2008

Ni-based amorphous alloy ribbon was prepared by a single-roller melt-spinning technique. Palladium coating was found to enhance significantly the absorption/desorption behavior of hydrogen in amorphous alloy. The hydrogen permeability of a Pd-coated $(Ni_{60}Nb_{40}){_{100-X}}$TaX(x=5, 10) amorphous alloy was examined in the temperature range of $623{\sim}773K$, comparable with those of $Pd_{60}-Cu_{40}$ alloys. The permeated hydrogen flux was increased with increasing the temperature and the difference of hydrogen pressure between the feed side and permeates side of the membrane. The Ni-based amorphous alloys were characterized by X-ray diffractometry(XRD) and differential scanning calorimetry(DSC). The morphology of surface and roughness was observed by using scanning electron microscopy(SEM) and atomic force microscopy(AFM).

• 한국수소및신에너지학회논문집
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• 제18권2호
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• pp.182-188
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• 2007

[ $Zr_{50}-Ni_{27}-Nb_{18}-Co_5$ ] amorphous alloys ribbon was prepared by a single-roller melt-spinning technique. In order to improve the hydrogen kinetics Pd-coating were carried out on each side of the amorphous ribbon. Pd prevents oxidation of Zr and catalyses the dissociation of molecular hydrogen to atomic hydrogen. In this work, the hydrogen embrittlement and surface properties on Zr-based amorphous alloys were investigated. The Zr-based amorphous alloys were characterized by X-ray diffractometry(XRD) and differential scanning calorimetry(DSC). The morphology of surface and roughness was observed by using scanning electron microscopy(SEM) and atomic force microscopy (AFM). A lattice parameter of both Pd and Zr-based amorphous alloy was increased after hydrogen permeation at 473 K. After hydrogen permeation at 473 K, some cracks were observed on the surface of Pd, which was the cause for the hydrogen embrittlement. The crystallization temperature of Zr-based amorphous alloy was decreased due to the permeated hydrogen.

• 한국수소및신에너지학회논문집
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• 제16권3호
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• pp.238-243
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• 2005

Mg and Mg-based alloys are most important hydrogen storage materials. It is a lightweight and low-cost materials with high hydrogen storage capacity. However, the formation of hydride at high temperature, the deterioration effect, the hydriding and dehydriding kinetics are bad factor for application. In this study, Mg and Ni have been produced by hydrogen induced mechanical alloying(HIMA) process. The raw materials, Mg(purity 99.9%) chip and Ni(purity 99.95%) chip was prepared by using a planetary ball mill apparatus(FRITSCH pulverisette 5). The balls to chips mass ratio(BCR) are 30:1. The hydrogen pressure induced 2.0MPa and milling times were 12, 24, 48, 72, 96 hours with a rotating speed of 200rpm. X-ray diffraction(XRD) analysis was made to characterize the crystallite size and misfit strain. The crystallite size measured by laser particle size analysis(PSA). Microstructure changes were investigated by scanning electron microscopy(SEM) and the transmission electron microscopy(TEM). The hydrogen storage properties were evaluated by using an Sivert's type automatic pressure-composition-therm(PCT) apparatus.

• 한국수소및신에너지학회논문집
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• 제17권4호
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• pp.389-394
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• 2006

Mg and Mg-based alloys are promising hydrogen storage alloys for renewable clean energy applications. It is a lightweight and low cost material with high hydrogen storage capacity. However, commercial applications of the Mg hydride are currently hindered by its high absorption/desorption temperature, and very slow reaction kinetics. In this work, we aim to study the absorption properties of the $Mg_2Ni$-5mass% Nb composite prepared by mechanical alloying under hydrogen. The absorption capacity of the sample is found to be about 3.0 wt.% at T=573 K and P=1.0 MPa. The absorption characteristics observed have been compared with those of the prepared $Mg_2Ni$.

• Korean Chemical Engineering Research
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• 제47권6호
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• pp.705-709
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• 2009

본 연구에서는 석송자 분진입자의 거동에 관한 실험적 연구결과를 바탕으로 한 분진화염 전파모델을 제시하였다. 화염전파속도는 분진농도와 함께 증가하여 석송자의 화학양론농도보다 높은 $170g/m^3$에서 최대로 나타났으며 $500g/m^3$까지 완만하게 감소 경향을 나타낸다. 농도 $47{\sim}200g/m^3$에 있어서, 분진입자속도는 화염전파속도에 비례하여 증가한다. 또한, 연소속도와 입자속도의 합이 화염전파속도에 근사한 값을 나타내고 있어, 분진농도에 따른 화염전파속도를 계산에 의해 추정이 가능하였으며, 입자의 거동이 분진의 화염전파속도를 이해하는데 유용하다는 것을 알 수 있었다.

• 한국수소및신에너지학회논문집
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• 제18권1호
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• pp.26-31
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• 2007

Hydrogen has a high potential to be a renewable substitute for fossil fuels, because of its high gravimetric energy density and environment friendliness. In particular, Magnesium have attracted much interest since their hydrogen capacity exceeds that of known metal hydrides. One of the approaches to improve the kinetic is addition of metal oxide. In this paper, the effect of $Fe_2O_3$ concentration on the kinetics of Mg hydrogen absorption reaction was investigated. $MgH_x-Fe_2O_3$ composites have been synthesized by hydrogen induced mechanical alloying. The powder synthesized was characterized by XRD, SEM and simultaneous TG, DSC analysis. The hydrogenation behaviors were evaluated by using a sievert's type automatic PCT apparatus. Absorption and desorption kinetics of Mg catalyzed with 5,10 mass% $Fe_2O_3$ are determined at 423, 473, 523, 573, 623K.