• Title/Summary/Keyword: enrichment

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Effect of Hydrogen Enriched LPG Fuelled Engine with Converted from a Diesel Engine

  • Choi, Gyeung-Ho;Lee, Jae-Cheon;Chung, Yon-Jong;Caton, Jerald;Han, Sung-Bin
    • Journal of Energy Engineering
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    • v.15 no.3 s.47
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    • pp.139-145
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    • 2006
  • The purpose of this study is to obtain low-emission and high-efficiency in LPG engine with hydrogen enrichment. The objective of this paper is to clarify the effects of hydrogen enrichment in LPG fuelled engine on exhaust emission, thermal efficiency and performance. The compression ratio of 8 was selected to avoid abnormal combustion. To maintain equal heating value of fuel blend, the amount of LPG was decreased as hydrogen was gradually added. The relative air-fuel ratio was increased from 0.8 to 1.3, and the ignition timing was controlled to be at MBT (minimum spark advance for best torque)

Different Aspects of Mulberry Leaves Supplementation with Various Nutritional Compounds in Sericulture

  • Etebari, K.;Kaliwal, B.B.;Matindoost, L.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.9 no.1
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    • pp.15-28
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    • 2004
  • The supplementation of mulberry leaves, with the aim of yield, enhancement using vitamins, minerals and other compounds have generally been attended from 1990s and many researches have been conducted. More than 30 different compounds from complementary nutrients have been analyzed and in different regions where different climates various results have been achieved. This review has attempted to discuss the results of different works on enrichment of mulberry leaves with supplementary compound. Generally the most effects of these compounds are in the regions where productive parameters are low. In the areas that follow a normal pattern in economical parameters the enrichment of the leaves havent have significant economical effects.

Simultaneous Enrichment of Novel Filamentous-Like Bacterial Population in Lab-Scale Granular Anaerobic Ammonia Oxidation (Anammox) Sequencing Batch Reactor (실험실 규모 입상 혐기성 암모늄 산화 연속회분식 반응조 내의 신종 사상균 동시 농화 배양에 관한 연구)

  • Park, Hongkeun
    • Journal of Korean Society on Water Environment
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    • v.29 no.3
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    • pp.377-382
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    • 2013
  • Enriching anammox bacteria (AMX) in a lab-scale granular sequencing batch reactor using local digester centrate, we observed the significant enrichment of the filamentous-like bacterial population. These bacteria were revealed as novel bacterial species (termed CHL) belonging to Chlorobi/Bacteroidetes phyla via Denaturing Gradient Gel Electrophoresis (DGGE). Further, niche differentiation of AMX and CHL quantification was observed in granule and filament biomass, suggesting AMX was dominant in the granule and CHL was dominant in the filament. Therefore, it was confirmed the structural role of CHL was indeed to aid the granule formation of the AMX. In parallel, the physiological role of CHL was suspected to degrade biopolymers in the digester centrate using nitrate as an electron acceptor.

Reference Spent Fuel and Its Characteristics for a Deep Geological Repository Concept Development

  • Choi, Jong-Won;Ko, Won-Il;Kang, Chul-Hyung
    • Nuclear Engineering and Technology
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    • v.31 no.6
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    • pp.23-38
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    • 1999
  • This study addresses the reference spent fuel and its characteristics for developing a geological repository concept. As a disposal capacity of the reference repository system to be developed, spent fuel inventories were projected based on the basis of the Nuclear Energy Plan of the Long-term National Power Program. The reference spent fuel encompassing a variability in characteristics of all existing and future spent fuels of interest was defined. Key parameters in the reference fuel screening processes were the nuclear and mechanical design parameters and the burnup histories for existing spent fuels as of 1996 and for future spent fuels with the more extended burnup the initial enrichment and its expected turnup. The selected reference fuel was characterized in terms of initial enrichment, bumup, dimension, gross weight and age. Also the isotopic composition and the radiological properties are quantitatively identified. This information provided in this study could be used as input for repository system development and performance assessment and applied in fuel material balance evaluation for the various types of back-end fuel cycle studies.

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Performance of a Foam Fractionator in a Lab-scale Seawater Recirculating Aquaculture System

  • Peng Lei;Jo Jae-Yoon
    • Fisheries and Aquatic Sciences
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    • v.6 no.4
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    • pp.187-193
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    • 2003
  • The performance of a foam fractionator to remove TAN, $NO_2,\;NO_3$, TSS, protein, and $PO_4-P$ at different superficial air velocities and foam overflow heights was evaluated in a lab-scale seawater recirculating system for culture of Korean rockfish (Sebastes schlegeli). The foam overflow rates increased with the increase of superficial air velocities, but decreased with the increase of foam overflow heights. Concentrations of all the water quality variables in the foam condensates increased with the increase of foam overflow height, but decreased with the increase of superficial air velocities. TSS, protein, and phosphate enrichment factors were within the range of 6.4-39.4, 1.6-7.3 and 1.2-3.9, respectively. Low values of TAN, $NO_2,\;and\;NO_3$ enrichment factors were obtained and they indicate that foam fractionation is rot an effective way to remove dissolved inorganic nitrogen. The calculated maximum daily removal values for TSS and protein were 10.9 and 1.4g, respectively.

영산강 하상퇴적물의 중금속 함량

  • 조영길;김주용
    • Journal of Environmental Science International
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    • v.7 no.3
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    • pp.281-290
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    • 1998
  • Thirty-eight sediment samples collected from the Youngsan River channel were analysed for Fe, Mn, Co, Cr, Cu, Nl, Zn and Pb to recognize the extent of contamination. Results showed that a wide range of contents was apparent far every metal over the study area. These differences have been mainly related to the textural variability of sediments. Exceptions to this were fecund in the contents of Cu, Zn, Pb and possibly Mn. The contents of Cu, Zn, Pb and Mn were particularly higher in the sediments loom the confluence of tributaries. Downstream profile of metal/Al ratios indicates that pollutant inputs from the Kwangju tributary are mainly responsible for enrichment of these metals in bed sediments of the Young-san River.

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Effects of $CO_2$ Enrichment During Seedling Stage on $CO_2$ Enrichment after Transplanting in the Culture of Leafy Vegetables (엽채류 육묘시 $CO_2$ 시비가 정식 후 $CO_2$ 시비효과에 미치는 영향)

  • 신석범;이현일;김일섭
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2000.10b
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    • pp.75-79
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    • 2000
  • 대부분의 채소작물류는 대기중의 $CO_2$ 농도보다 높은 농도조건에서 $CO_2$ 포화점이 형성되기 때문에 $CO_2$ 농도를 높임으로서 광합성량을 증가시키고 작물의 생육을 촉진시킬 수 있다. 저온기에 밀폐된 시설내에서 작물을 재배할 경우 주간의 $CO_2$ 농도는 거의 기아상태까지 낮아지고 환기를 하더라도 대기농도보다 30-50ppm 정도 떨어지는 것이 일반적이기 때문에 시설내 $CO_2$ 시비효과는 매우 큰 것으로 평가되고 있다. $CO_2$ 시비효과는 엽근채류에 있어서 40%, 과채류에서는 20% 정도의 수량증대가 인정되어 작물간에 큰 차이를나타내고 있다. (중략)

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A Meshfree method Based on the Local Partition of Unity for Cohesiv cracks (국부 단위분할 원리에 기초한 무요소법의 점성균열 모델)

  • Zi Goang-Seup;Jung Jin-Kyu;Kim Byeong-Min
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.357-364
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    • 2006
  • The meshfree method is extended by the local partition of unity method to model the cohesive cracks in two dimensional continuum The shape function of a particle whose domain of influence is completely cut by a crack is enriched by the step enrichment function. If the domain of influence contains a crack tip inside, it is enriched by the branch enrichment function without the stress singularity. It is found that this method is more accurate and converges faster than the meshless methods for LEFM cracks based on the visibility concept Several staic and dynamic examples are solved to verify the method.

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Nitrated Proteome in Human Embryonic Stem Cells

  • Kang, Jeong Won;Hwang, Daehee;Kim, Kwang Pyo
    • Mass Spectrometry Letters
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    • v.7 no.4
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    • pp.85-90
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    • 2016
  • Post-translational modifications (PTMs) of proteins regulate self-renewal and differentiation in embryonic stem cells (ESCs). Nitration of tyrosine residues of proteins in ESCs modulates their downstream pathways, which can affect self-renewal and differentiation. However, protein tyrosine nitration (PTN) in ESCs has been rarely studied. We reviewed 23 nitrated sites in stem cell proteins. Functional enrichment analysis showed that these nitrated proteins are involved in signal transduction, cell adhesion and migration, and cell proliferation in ESCs. Comparison between the nitrated and known phosphorylated sites revealed that 7 nitrated sites had overlapping phosphorylated sites, indicating functional links of PTNs to their associated signaling pathways in ESCs. Therefore, nitrated proteome provides a basis for understanding potential roles of PTN in self-renewal and differentiation of ESCs.

Nitrogen self-enrichment in the starburst galaxies under the metal poor environments

  • Chung, Ji-Won;Sung, Eon-Chang;Rey, Soo-Chang;Kyeong, Jae-mann
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.29.2-29.2
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    • 2010
  • We present elemental abundances of 412 blue compact dwarf galaxies (BCDs) at z=0.2~0.5 using the Sloan Digital Sky Survey (SDSS) DR7. The gas-phase nitrogen to oxygen abundance ratios (N/O) of sample galaxies increase as the oxygen to hydrogen abundance ratios (O/H) decrease. This indicates that the nitrogen is more enriched than the oxygen. We found that there is a noticeable distinction between the merger candidates and the isolated galaxies. Merging candidates show more enrichment of nitrogen abundance compared to isolated galaxies. On the other hand, neon and oxygen abundances for merging candidates are slightly lower than the isolated systems. We discuss the main cause of these trends with internal mixing and mass loss by fast rotation of young massive stars. We also discuss the environmental effect to the relation between specific star formation rate and galaxy mass.

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