• Title/Summary/Keyword: bio gas

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Using a 7.0T animal MRI comparison of ADC values and Pathologic Findings (7.0T 동물용 MRI을 이용한 종양의 현성확산계수와 병리학적 소견의 평가)

  • Seong, jae gu;Lim, cheong hwan
    • Proceedings of the Korea Contents Association Conference
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    • 2011.05a
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    • pp.201-202
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    • 2011
  • 본 연구에는 7.0T 동물용 자기공명영상장치를 이용하여 인간의 췌장암 세포인 CFPAC-1를 이종 이식한 쥐에서 자기공명영상을 획득하여 최적화된 검사 Protocol을 정립하며, 동물 실험에서 밝혀진 종양특성과 확산강조영상과의 비교 분석을 해보고 현성확산계수 영상이 췌장암 이종이식 모형의 종양 세포 내부 구조에 관하여 어떠한 정보를 제공 할 수 있는지 알아보고자 한다. 13마리의 쥐의 26개의 종양을 전형적으로 주입 후에 2~4주 뒤에 직경이 5~10mm가 되었을 때 imaged 하였으며, pathologic specimenm을 위해 sacrificed 하였다. isofluoran gas anesthesia를 이용하여 동물 마취 하였다. 사용된 장비로는 small-animal MR images (7.0-T)를 (Bruker BioSpin GmbH, Rheinstetten, Germany)이용하여 Fast T2-weighted 와 single-shot EPI DW image를 얻었다. 종양은 H&E 염색과 CD31와 VEGF에 대한 면역조직학 염색을 하여 종양의 cellularity와 microvessel density(MVD), 종양 내 괴사 정도를 평가하였다. CFPAC-1의 현성확산계수값은 $0.7327{\pm}0.1075{\pm}10^{-3}mm2/s$이였으며, 현성확산계수는 종양내 괴사 정도와 연관성을 보였다(R = 0.7417, p = 0.0001) 이처럼 현성확산계수는 종양 내 괴사 정도 등의 현미경적구조변화를 반영하는 대리인자로 사용될 수 있음을 확인하였다.

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Bio-filters for the Treatment of VOCs and Odors - A Review

  • Vikrant, Kumar;Kim, Ki-Hyun;Szulejko, Jan E.;Pandey, Sudhir Kumar;Singh, R.S.;Giri, B.S.;Brown, Richard J.C.;Lee, S.H.
    • Asian Journal of Atmospheric Environment
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    • v.11 no.3
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    • pp.139-152
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    • 2017
  • Excessive amounts of volatile organic compounds (VOCs) and odorants discharged into the environment are highly dangerous to human health as well as to ecological systems. Biological treatments of waste gas streams, called biofiltration, containing VOCs and odorous compounds has gained much attention because biofilters are more cost effective and environmentally friendly than conventional air pollution control technologies. This review provides an overview of biotrickling filtration, which is a type of biofiltration including continuous trickled-water flow inside filter media, for VOC and odor abatement. The configuration, design, cost effectiveness, removal capacity and environmental impact of this techniques and the future research and development needs in this area are all considered.

Synthesis and reactivity over molybdenum carbide crystallites

  • Choi, Jeong-Gil
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.2
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    • pp.74-79
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    • 2010
  • The synthesis and reactivities of molybdenum carbide crystallites were examined in this study. Especially, the effect of synthesis conditions were scrutinized on the preparation of molybdenum carbide crystallites. In order to perform this purpose, various characterization techniques such as BET surface area and oxygen uptake measurements were employed for the synthesized molybdenum carbide crystallites. First of all, the molybdenum carbide crystallites were synthesized using molybdenum oxide crystallites and methane gas or methane-hydrogen mixture. The experimental results showed that BET surface areas ranged from $7.4m^2/g$ to $31m^2/g$ and oxygen uptake values varied from $8.1{\mu}mol/g$ to $24.3{\mu}mol/g$. The Mo compounds were found to be active for ammonia decomposition reaction. Even though there are some molybdenum carbide crystallites that were exceeded by Pt/$Al_2O_3$ crystallite, the steady state reactivities for other molybdenum carbide crystallites were comparable to or even higher than that determined for the Pt/$Al_2O_3$ crystallite. These results implied that molybdenum carbide crystallites could be one of the promising crystallites that might be substitutes for Pt-like noble metal crystallites in the petroleum processes.

Synthesis of graphene nano-sheet without catalysts and substrates using fullerene and spark plasma sintering process

  • Jun, Tae-Sung;Park, No-Hyung;So, Dea-Sup;Lee, Joon-Woo;Lim, Hak-Sang;Ham, Heon;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.1
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    • pp.27-30
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    • 2013
  • Catalyst-free graphene nano-sheets without substrates have been synthesized using fullerene and a high direct current (dc) pulse in the spark plasma sintering (SPS) process. Graphene nano-sheets were synthesized directly in the gas phase of carbon atoms which are generated from fullerene at a temperature of $600^{\circ}C$. Characterization has been carried out by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD).

The Impacts of Changes of Temperature and Precipitation Amount on Red Pepper Yields (기온 및 강수량 변동이 노지 건고추 단수에 미치는 영향)

  • Cho, Jae-Hwan;Suh, Jeong-Min;Kang, Jum-Soon;Hong, Chang-Oh;Kim, Jin-Ho;Lee, Sang-Gyu
    • Journal of Environmental Science International
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    • v.21 no.12
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    • pp.1503-1510
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    • 2012
  • The purpose of this article is analyzing the impacts of climate change on red pepper yield in Korea, with employing a panel data regression model. Our results show that there is a negative impacts of high temperature and precipitation amount on red pepper yields. Especially high temperature and rainfall in July cause serious damage to red pepper yield. According to the reduction schedule on greenhouse gas emission(RCP 8.5 scenario.), red pepper yield would be 25.4% lower than it is, for reasons of high temperature and rainfall damages by the end of 21st century.

Development of Pilot-Scale Scrubber for Simultaneous Removal of $SO_2/NO$

  • Jung, Seung-Ho;Jeong, Gwi-Taek;Lee, Gwang-Yeon;Park, Don-Hee;Cha, Jin-Myeong
    • 한국생물공학회:학술대회논문집
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    • 2005.10a
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    • pp.468-474
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    • 2005
  • SOx and NOx are known major precursors of acid rain and thus the abatement of their emissions is a major target in air pollution control. To obtain basic data on the removal process of simultaneous $SO_2/NO$, the optimal reaction condition and the composition of reaction solution for simultaneous removal of $SO_2/NO$, ware investigated using a bubble column reactor. Pilot scrubber was consisted of scrubber, filter and control box. Dust removal rate was 83, 92, and 97% with catalyst flux of 0.5, 0.8, 1.5 L/min, respectively Average dust removal efficiency with a kind of nozzle was about 94 and 90% in STS FF6.5 (5/8in.) and 14 of P.P W(1.0in.), respectively Dust and $SO_2$ were removed more than 98-96% regardless of reactor number. In the case of NO gas, removal yield of 83.3% was achieved after 48 hours in 1 stage, also removal yield of 95.7% was reached in 2 stages. In tile case of application of STS (5/8 in.) and P.P (1.0 in.) as used fill packing, removal efficiency was reached higher than 98% without related to of kind of fill packing.

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N-nitroso-N-methylurea and N-nitroso-N-ethylurea Decrease in Nitric Oxide Production in Human Malignant Keratinocytes

  • Moon, Ki-Young
    • Biomedical Science Letters
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    • v.24 no.1
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    • pp.50-54
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    • 2018
  • N-nitroso-N-methylurea (NMU) and N-nitroso-N-ethylurea (NEU), direct alkylating chemical mutagens and carcinogens, are shown to be the upregulators of cellular $NF-{\kappa}B$, regulating various genes that mediate tumorigenesis and carcinogenesis. Nitric oxide (NO), a toxic reactive radical gas, has been known to induce programmed cell death or apoptosis in various cells. Therefore, the assessment of NO production was examined to elucidate the possible contribution of NO release to the chemical carcinogenic potency of NMU and NEU in human skin cells. NMU and NEU did not alter the NO production, but they caused a significant downregulation of the NO generation on lipopolysaccharide (LPS)-induced NO production at concentrations ranging from $2{\sim}5{\mu}M$. The degree of downregulation of NO by NMU and NEU decreased up to 15% and 20%, respectively, compared to the control. These results demonstrate that the LPS-inducible keratinocytes NO synthase is involved in modulating carcinogenic potency by NMU and NEU, and the regulation of the cellular $NF-{\kappa}B$ activity by NMU and NEU is negatively correlated with the level of LPS-induced NO production in human skin cells. The findings of this study suggest the hypothesis that NMU and NEU-induced carcinogenesis may be associated with the downregulation of NO production, and the inducible NO may play an important role in NMU and NEU-induced carcinogenicity in human epidermal keratinocytes.

Recent Trends of the Development of Photobioreactors to Cultivate Microalgae (미세조류 배양을 위한 광생물반응기 개발의 기술동향)

  • Kim, Jong-Tye;Ahn, Dong-Gyu;Park, Jong-Rak;Park, Jeong-Woo;Jeong, Sang-Hwa
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.2
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    • pp.125-132
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    • 2011
  • This paper describes current status and future prospects of the mass production of microalgae biomass. Microalgae have attracted considerable attention since they not only effectively fix $CO_2$ gas during their metabolic process but also have the great potential to be utilized for producing valuable substances as a kind of efficient light-harvesting cell factories. In this review, we outline various types of photobioreactors employed for mass production of biomass by culturing microalgae in a well controlled way and give an overview about the present state of affairs, both domestic and international, in the field of the microalgal culturing technologies.

Pyrolysis of Waste Oriental Medicine Byproduct Obtained from the Decoction Process of Achyranthes Root (우슬(Achyranthes Root) 탕제 후 얻어진 폐한약재 부산물의 열분해)

  • Park, Ji Hui;Jeong, JaeHun;Lee, Ji Young;Kim, Young-Min;Park, Young-Kwon
    • Applied Chemistry for Engineering
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    • v.29 no.4
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    • pp.474-478
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    • 2018
  • Thermal decomposition of waste Achyranthes Root (WAR) emitted from its decoction process was investigated using a TG analyzer and a fixed-bed reactor. The WAR had the larger C and fixed carbon content than fresh AR (FAR) due to the extraction of hemicelluloses from FAR during decoction process. Thermogravimetric (TG) analysis results also revealed the elimination of hemicellulose by its decoction. Relatively high contents of the cellulose and lignin made high contents of their typical pyrolyzates, such as acids, ketones, furans, and phenols, in the pyrolysis of WAR using the fixed-bed reactor. The increase of pyrolysis temperature from 400 to $500^{\circ}C$ increased yields of oil and gas due to the more effective cracking efficiency of WAR at a higher temperature. The chemical composition of product oil was also changed by applying the higher pyrolysis temperature, which increased the selectivity to furans and phenols.

A Study for Separation of $CH_4$ and $CO_2$ from Biogas (바이오가스의 $CH_4$, $CO_2$의 분리방법 연구)

  • Lee, Taek-Hong;Kim, Jae-Young;Chang, Sae-Hun;Lee, Hyo-Suk;Choi, Ik-Hwan
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.1
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    • pp.72-79
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    • 2010
  • This paper is studying the selective separation of methane and carbon dioxide which are the main ingredients of biogas. Adsorption performance of molecular sieve 13x for carbon dioxide seems to be reasonable. In this experiments carbon dioxide contains about 3~5 ppm of methane and it is impossible to obtain high purity carbon dioxide. Applying the low temperature technique, it is possible to separate methane and carbon dioxide from bio gas. PRO II simulation shows results a small change of liquefaction temperatures and no difference with the used thermodynamic models. Applying low temperature technique, It is possible to separate carbon dioxide and methane from biogas.