• 제목/요약/키워드: $H_{2}$ evolution

검색결과 658건 처리시간 0.025초

생장조절물질(生長調節物質) 처리(處理)가 콩나물의 생육(生育) 및 세근발생(細根發生)에 미치는 영향(影響) - II. 생장조절물질(生長調節物質) 처리(處理)가 콩나물의 ethylene 발생(發生)에 미치는 효과 (Effect of Plant Growth Regulator Treatments on the Growth and Lateral Root Formation in Soybean Sprouts - 2. Effect of Plant Growth Regulator Treatment on the Ethylene Evolution in Soybean Sprouts)

  • 강충길;이정명;판제
    • 한국잡초학회지
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    • 제9권2호
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    • pp.90-96
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    • 1989
  • 생장조절물질(生長調節物質)의 처리(處理)가 콩나물의 ethylene 발생(發生)에 미치는 효과(效果)에 관(關)하여 연구(硏究)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 콩나물의 ethylene 발생(發生)에 미치는 auxin의 처리(處理)는 뚜렷한 영향(影響)이 보이지 않았다. 2. 콩나물의 ethylene 발생(發生)에 미치는 cytokinin 및 유사물질(類似物質)의 처리효과(處理效果)는 BA가 ethylene 발생(發生)을 크게 촉진(促進)시킨 반면(反面) kinetin, zeatin, zeatin riboside는 미미(微微)하였다. 3. 콩나물의 ethylene 발생(發生)에 미치는 BA 농도별(濃度別) 처리효과(處理效果)는 농도(濃度)가 높을 수록 ethylene 발생(發生)이 증가(增加)되었다. 4. BA의 처리(處理)는 단기간내(短期間內) ethylene 발생(發生)을 증가(增加)시켜서 신장억제(伸長抑制)와 비대촉진(肥大促進) 효과(效果)를 보이나 4PU-30은 ethylene 발생(發生)을 지속적(持續的)으로 증대(增大)시키는 효과(效果)를 보였다. 5. 생장조절물질(生長調節物質)이 처리(處理)된 콩나물에서의 ethylene 발생정도(發生程度)는 BA 25ppm > IAA 25 + BA 25 ppm ${\geq}$ 4 PU-30 25 ppm > IAA 25 ppm > control 순(順)이었다. 6. 콩나물의 세근발생(細根發生)은 cytokinin 중(中) BA에 의(依)해 억제(抑制)되며, 비대촉진(肥大促進)은 ethylene에 의해 촉진(促進)되는데, BA는 ethylene 발생(發生)을 크게 촉진(促進)시켰다.

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Development of Visible-light Responsive $TiO_2$ Thin Film Photocatalysts by Magnetron Sputtering Method and Their Applications as Green Chemistry Materials

  • Matsuoka, Masaya
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2010년도 춘계학술발표대회
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    • pp.3.1-3.1
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    • 2010
  • Water splitting reaction using photocatalysts is of great interest in the utilization of solar energy [1]. In the present work, visible light-responsive $TiO_2$ thin films (Vis-$TiO_2$) were prepared by a radio frequency magnetron sputtering (RF-MS) deposition method and applied for the separate evolution of $H_2$ and $O_2$ from water as well as the photofuel cell. Special attentions will be focused on the effect of HF treatment of Vis-$TiO_2$ thin films on their photocatalytic activities. Vis-$TiO_2$ thin films were prepared by an RF-MS method using a calcined $TiO_2$ plate and Ar as the sputtering gas. The Vis-$TiO_2$ thin films were then deposited on the Ti foil substrate with the substrate temperature at 873 K (Vis-$TiO_2$/Ti). Vis-$TiO_2$/Ti thin films were immersed in a 0.045 vol% HF solution at room temperature. The effect of HF treatments on the activity of Vis-$TiO_2$/Ti thin films for the photocatalytic water splitting reaction have been investigated. Vis-$TiO_2$/Ti thin films treated with HF solution (HF-Vis-$TiO_2$/Ti) exhibited remarkable enhancement in the photocatalytic activity for $H_2$ evolution from a methanol aqueous solution as well as in the photoelectrochemical performance under visible light irradiation as compared with the untreated Vis-$TiO_2$/Ti thin films. Moreover, Pt-loaded HF-Vis-$TiO_2$/Ti thin films act as efficient and stable photocatalysts for the separate evolution of $H_2$ and $O_2$ from water under visible light irradiation in the presence of chemical bias. Thus, HF treatment was found to be an effective way to improve the photocatalytic activity of Vis-$TiO_2$/Ti thin films. Furthermore, unique separate type photofuel cell was fabricated using a Vis-$TiO_2$ thin film as an electrode, which can generate electrical power under solar light irradiation by using various kinds of biomass derivatives as fuel. It was found that the introduction of an iodine ($I^-/{I_3}^-$) redox solution at the cathode side enables the development of a highly efficient photofuel cell which can utilize a cost-efficient carbon electrode as an alternative to the Pt cathode.

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Rhodopseudomonas sphaeroides K-7 의 질소고정 효소 의존성 수소생성에 관한 연구 (A Study on Nitrogenase - Mediated Evolution of Molecular Hydrogen in Rhodopseudomonas sphaeroides K-7)

  • Lee, Jeong-Kug;Moo Bae
    • 한국미생물·생명공학회지
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    • 제11권3호
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    • pp.211-216
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    • 1983
  • R. sphaeroides K- 7에 의한 수소생성과 질소고정효소(nitrogenase)와의 연관성을 조사한 결과 수소생성은 질소고정효소에 의해 이루어지는 것으로 나타났다. 또한 수소생성은 수소효소(hydrogenase)와 무관하며 박테리오클로로필의 농도와도 무관한 것으로 나타났다. 글루타민산이 in vivo에서 질소고정효소의 활성도를 조절하는데 중요한 역할을 할 수 있는 것으로 나타났으며 질소개스를 이용해 키운 세균을 글루타민산 존재하로 옮겼을때 보다 큰 정도의 수소생성능 및 질소고정효소 활성도가 나타났다.

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몰리브덴(V)의 트리에틸렌테트라아민의 착물합성과 그 성질 (Preparation and Characterization of Triethylenetetraamine Complexes of Molybdenum(V))

  • 김창수;오상오
    • 대한화학회지
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    • 제26권3호
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    • pp.155-159
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    • 1982
  • Trien$H_4(MoOCl_5)_2,\;(MoOCl_3)_2$(trien) 및 $Mo_2O_4Cl_2$(trien)등의 몰리브덴(V)의 트리에틸렌 테트라아민착물을 합성하고 이들 착물의 화학적, 자기적 및 분광학적 성질을 조사하였다. Trien$H_4(MoOCl_5)_2$는 파란색 결정으로 무수에탄올에서 탈염화수소시켜 비전해질인 상자성착물 $H_4(MoOCl_5)_2$(trien)을 얻고 또한 $H_4(MoOCl_5)_2$Trien를 가수분해시켜 갈색의 비전해질인 반자성착물$Mo-2O_4Cl_2$(trien)을 얻었다.

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바다갯고사리과(바다나리강, 바다나리목, 협중강아목)의 1 한국미기록종 (A New Record of Thalassometridae (Crinoidea, Comantulida, Oligophreata) in Korea)

  • 신숙
    • Animal Systematics, Evolution and Diversity
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    • 제20권2호
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    • pp.185-189
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    • 2004
  • 대한해협에서 채집한 바다나리류를 동정$\cdot$분류한 결과 바다갯고사리과 (Thalassometridae) 에 속하는 1종의 한국미기록종, 푸른발갯고사리 Parametra orion (A. H. Clark. 1907)로 밝혀져 재기재하고 보고한다. 바다갯고사리과는 한국에서 처음으로 보고된다.

광산란과 입자포집을 이용한 동축류 확산화염 내의 실리카 입자의 성장 측정(I) - 화염온도의 영향 - (An Experimental Study of Silica Particle Growth in a Coflow Diffusion Flame Utilizing Light Scattering and Local Sampling Technique (I) - Effects of Flame Temperature -)

  • 조재걸;이정훈;김현우;최만수
    • 대한기계학회논문집B
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    • 제23권9호
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    • pp.1139-1150
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    • 1999
  • The evolution of silica aggregate particles in coflow diffusion flames has been studied experimentally using light scattering and thermophoretic sampling techniques. The measurements of scattering cross section from $90^{\circ}$ light scattering have been utilized to calculate the aggregate number density and volume fraction using with combination of measuring the particle size and morphology through the localized sampling and a TEM image analysis. Aggregate or particle number densities and volume fractions were calculated using Rayleigh-Debye-Gans and Mie theory for fractal aggregates and spherical particles, respectively. Of particular interests are the effects of flame temperature on the evolution of silica aggregate particles. As the flow rate of $H_2$ increases, the primary particle diameters of silica aggregates have been first decreased, but, further increase of $H_2$ flow rate causes the diameter of primary particles to increase and for sufficiently larger flow rates, the fractal aggregates finally become spherical particles. The variation of primary particle size along the upward jet centerline and the effect of burner configuration have also been studied.

Mg-13.5wt%Ni 합금 수소화합물의 수소방출에 대한 부피법에 의한 열분석 (Volumetric Thermal Analysis of Hydrogen Desorption from Mg-13.5wt%Ni Hydride)

  • 한정섭;박경덕
    • 한국수소및신에너지학회논문집
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    • 제26권4호
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    • pp.308-317
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    • 2015
  • To investigate the effect of microstructure on the formation of the desorption peak, the volumetric thermal analysis technique (VTA) was applied to the Mg-13.5 wt% Ni hydride system. The sample made by the HCS (hydriding combustion synthesis) process had two kinds of Mg microstructures. Linear heating was started with various constant heating rates. Only one peak was appeared in the case of the small initial hydrogen wt% (0.83 wt%). Yet, two peaks were appeared with increasing initial hydrogen wt% (1.85 and 3.73 wt%) when only Mg was hydrogenated. The first peak was formed through the evolution of hydrogen from $MgH_2$, made by eutectic Mg. The second peak was formed through the evolution of hydrogen from $MgH_2$, made by primary Mg. Therefore, this result shows that the microstructure also has a considerable effect on forming the desorption peak. We have also derived the hydrogen desorption equations by VTA to get apparent activation energy when the rate-controlling step for the desorption of the hydrided system is the diffusion of hydrogen through the ${\alpha}$ phase and the chemical reaction ${\beta}{\rightarrow}{\alpha}$.

Gas Outflow in SDSS AGN-host Galaxies

  • 배현진;우종학;오세명
    • 천문학회보
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    • 제37권2호
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    • pp.85.1-85.1
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    • 2012
  • Energetic outflow from active galactic nuclei (AGNs) may play a critical role in galaxy evolution. We present a velocity diagnostics for detecting gas outflow in the narrow-line region of Type-2 AGNs using line-of-sight velocity offset of the [O III]${\lambda}5007$ and $H{\alpha}$ emission lines with respect to the systemic velocity of stars in host galaxies. We apply the diagnostics to nearby galaxies at 0.02 < z < 0.05: 3775 AGN-host and 907 star-forming galaxies as a comparison sample, which are selected from the Sloan Digital Sky Survey DR7. After obtaining a best-fit stellar population model for the continuum and a systemic velocity based on stellar lines, we subtract stellar component to measure velocity offsets of each emission line. We find a sample of 169 AGN-host galaxies with outflow signatures, displaying a larger velocity shift of [O III] than that of $H{\alpha}$, as expected in a decelerating outflow model. We find that the offset velocity of [O III] increases with Eddington ratio, suggesting that gas outflow depends on the energetics of AGN.

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Two Species of Chalinidae (Demospongiae: Haplosclerida) from Korea

  • Jeon, Yong-Jin;Sim, Chung-Ja
    • Animal Systematics, Evolution and Diversity
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    • 제24권2호
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    • pp.147-150
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    • 2008
  • Two species of the family Chalinidae, Haliclona (Gellius) tubulensis n. sp. and Haliclona (Gellius) marismedi were collected from Hongdo Island and Gageodo Island, Korea during 2004-2007. H. (G.) tubulensis n. sp. is closely related to H. (G.) coreana in type of spicules and growth form. But it is different in size of toxas and oscules. Toxa of H. (G.) tubulensis n. sp. is one type and its oscules are tuberculated. The toxa of H. (G.) coreana is two types and lacks projections. The overall shape and spiculation of H. (G.) marismedi are nearly identical with specimens described by Pulitzer-Finali (1977).