• 제목/요약/키워드: $Ho^{3+}$

검색결과 52,539건 처리시간 0.073초

Atmospheric Photochemistry in Low-and High-NOx Regimes

  • Kim, Do-Yong;Soda, Satoshi;Kendo, Akira;Oh, Jai-Ho
    • 한국환경과학회지
    • /
    • 제16권1호
    • /
    • pp.1-8
    • /
    • 2007
  • Atmospheric photochemistry of $O_3-NOx-RH$ were considered theoretically, to clarify the reasons for the different trends of between the formation of photochemical oxidants (Ox) and its primary pollutants for the Low-and High-NOx regimes. Equations of OH, $HO_2$, and production of ozone ($O_3$) as a function of nitrogen oxides (NOx) and reactive hydrocarbons (RH) were represented in this study. For the Low-NOx regime, $HO_2$ radical is proportional to RH but independent of NOx. OH radical is proportional to NOx but inversely-proportional to RH. $O_3$ production is proportional to NOx but has a weak dependence on RH. For the High-NOx regime, OH and $HO_2$ radicals concentrations and $O_3$ production are proportional to RH but inversely-proportional to NOx. In addition, the Osaka Bay and surrounding areas of Japan were evaluated with the mass balance of odd-hydrogen radicals (Odd-H) using CBM-IV photochemical mechanism, in order to distinguish the Low- and High-NOx regimes. The Harima area (emission ratio, RH/NOx = 6.1) was classified to the Low-NOx regime. The Hanshin area (RH/NOx = 3.5) and Osaka area (RH/NOx = 4.3) were classified to the High-NOx regime.

Effect of groundwater level change on piled raft foundation in Ho Chi Minh City, Viet Nam using 3D-FEM

  • Kamol Amornfa;Ha T. Quang;Tran V. Tuan
    • Geomechanics and Engineering
    • /
    • 제32권4호
    • /
    • pp.387-396
    • /
    • 2023
  • Ground subsidence, which is a current concern that affects piled raft foundations, has occurred at a high rate in Ho Chi Minh City, Viet Nam, due primarily to groundwater pumping for water supply. In this study, the groundwater level (GWL) change affect on a piled raft foundation was investigated based on the three-dimensional finite element method (3D-FEM) using the PLAXIS 3D software. The GWL change due to global groundwater pumping and dewatering were simulated in PLAXIS 3D based on the GWL reduction and consolidation. Settlement and the pile axial force of the piled raft foundation in Ho Chi Minh subsoil were investigated based on the actual design and the proposed optimal case. The actual design used the piled foundation concept, while the optimal case applied a pile spacing of 6D using a piled raft concept to reduce the number of piles, with little increased settlement. The results indicated that the settlement increased with the GWL reduction, caused by groundwater pumping and dewatering. The subsidence started to affect the piled raft foundation 2.5 years after construction for the actual design and after 3.4 years for the optimal case due to global groundwater pumping. The pile's axial force, which was affected by negative skin friction, increased during that time.

In-situ Calibration of the Hydroperoxyl Radical Using an Immobilized TiO2 Photocatalyst in the Atmosphere

  • Kwon, Bum-Gun
    • Bulletin of the Korean Chemical Society
    • /
    • 제29권4호
    • /
    • pp.785-789
    • /
    • 2008
  • The present study is the first report of utilizing $TiO_2$ photocatalyst to analytically calibrate the hydroperoxyl radical ($HO_2\;^{\cdot}$). An in-situ calibration method of $HO_2\;^{\cdot}$ is proposed for air monitoring by using an 2-methyl-6-(pmethoxyphenyl)- 3,7-dihydroimidazo-[1,2-a]pyrazin-3-one (MCLA)-chemiluminescence (CL) technique. In this method, $HO_2\;^{\cdot}$($pK_a$ = 4.80) is produced by the ultraviolet (UV) photolysis of immobilized $TiO_2$ using a constant flow rate of air equilibrated water, in which $HO_2\;^{\cdot}$ is controlled by using various lengths of knotted tubing reactor (KTR). The principle of the proposed calibration is based on the experimentally determined halflife ($t_{1/2}$) of $HO_2\;^{\cdot}$ and its empirically observed pH-dependent rate constant, $k_{obs}$, at a given pH. The concentration of $HO_2\;^{\cdot}$/$O_2\;^{\cdot}$− is increased as pH increases. This pH dependence is due to the different disproportionative reactivities between $HO_2\;^{\cdot}$/$O_2\;^{\cdot}$− and $HO_2\;^{\cdot}$/$O_2\;^{\cdot}$−. Experimental results indicate the practical feasibility of the approach, producing very promising method.

Pervaporation separation of water/ethanol mixture through tubular zeolite membranes

  • Matsui, Shigetoshi;Ikeda, Madoka;Shinma, Shuji;Arano, Manabu;Mizoguchi, Kensaku;Ikeda, Shiro;Sawasaki, Toshiaki;Nakane, Takashi
    • 한국막학회:학술대회논문집
    • /
    • 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
    • /
    • pp.98-101
    • /
    • 2004
  • Utilization of biomass resources has considerable contribution to the reduction of carbon dioxide emission. Ethanol is one of the biomass products and is used as an additive to gasoline in several countries. Conventional process to produce ethanol involves energy-intensive azeotropic distillation. Pervaporation (PV) or vapor permeation (VP) is considered to be an alternative separation process to the conventional process.(omitted)

  • PDF

생쥐 대식세포에서 HO-1 발현 유도를 통한 chrysoeriol의 항산화 효과 (Fortified Antioxidative Potential by Chrysoeriol through the Regulation of the Nrf2/MAPK-mediated HO-1 Signaling Pathway in RAW 264.7 Cells)

  • 박충무
    • 생명과학회지
    • /
    • 제28권1호
    • /
    • pp.43-49
    • /
    • 2018
  • Chrysoeriol은 alfalfa에서 주로 발견되는, 식물계에 많이 분포하고 있는 flavone으로 전통의학에서 소화불량, 천식, 비뇨기계 이상의 치료에 사용되어 왔다. 최근의 연구에서는 항염증 효과가 있는 것으로 밝혀졌으나 항산화 효과에 대한 분석은 없었다. 본 연구에서는 chrysoeriol의 항산화 효과와 그 분자적 기전을 RAW 264.7 cell에서 세포생존율, reactive oxygen species (ROS)와 Western blot분석을 통해 알아보고자 하였다. Chrysoeriol은 lipopolysaccharide(LPS)에 의해 발생한 ROS를 세포독성없이 농도의존적으로 제거하였다. 그리고 항산화효과를 보이는 2상 효소 중 하나인 heme oxygenase (HO)-1의 발현을 강하게 유도하였고, 그와 동시에 전사인자인 Nrf2의 핵내 이동도 촉진하는 것으로 밝혀졌다. 특히, 산화스트레스에 대한 세포내 산화환원항상성 유지에 중요한 역할을 하고 있는 것으로 알려진 mitogen activated protein kinase (MAPK)와 phosphoinositide 3-kinase (PI3K)의 분석결과, chrysoeriol은 extracellular signal regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK)와 p38의 인산화를 통해 HO-1의 발현을 유도하는 것으로 나타났다. HO-1에 의한 항산화 효과를 확인하기 위하여 chrysoeriol을 전처리한 후 t-BHP에 의한 산화 스트레스에 세포를 노출시킨 결과, chrysoeriol 처리에 의해 세포사멸이 줄어드는 것을 확인하였고, HO-1의 유도제와 억제제의 처리에 따라 세포생존율 또한 조절되는 것을 확인할 수 있었다. 따라서, chrysoeriol은 HO-1의 발현을 유도하여 항산화 효과를 높이고 이것은 Nrf2/MAPK 신호전달 체계에 의한다는 것을 알 수 있었다.

잣버섯 신품종 『곤지10호』 특성 (Characteristics of a new variety 『Gonji10ho』 in Neolentinus lepideus)

  • 전대훈;장명준;하태문;이윤혜;최종인;주영철;유영복
    • 한국버섯학회지
    • /
    • 제11권4호
    • /
    • pp.249-253
    • /
    • 2013
  • 잣버섯의 다수성 신품종 개발을 위하여, 단포자교잡에 의해 육성된 신품종 '곤지10호'의 주요 특성은 다음과 같다. 균사생장적온은 $29^{\circ}C$, 버섯 발생 및 생육온도는 $20{\pm}1^{\circ}C$로 대조품종과 같았으며, 균사 활력도 대조품종과 비슷하였다. 갓형태는 반반구형이며, Hunter 색체값으로 볼 때 갓색은 L 79.3, b 24.8, 대색은 L 84.3, b 10.9로, 갓색에 있어서 대조품종에 비하여 황색도가 더 높았다. 미송톱밥+옥분(90:10, v/v)배지로 병재배 시 배양일수는 $22{\pm}1^{\circ}C$에서 35일, 발이일수와 자실체생육일수는 $20{\pm}1^{\circ}C$에서 15일과 12일로 재배일수는 62일이 되어 대조품종보다 2일 길었다. 자실체 생육 특성은 대조품종에 비하여 갓두께는 6.3 mm로 두꺼웠으며, 유효경수는 3.5개로 적었고 대 직경은 21.6 mm로 굵었다. 재배접종 후 배양 및 생육 중 푸른곰팡이병(Trichoderma spp.) 발생율은 4.9%로 대조품종보다 낮았다. 수량은 생산력 검정 결과 병재배 시 900 ml병당 69.6 g, 봉지재배 시 1 kg봉지당 114.2 g으로 대조품종 대비 38%와 10%씩 많았다. 자실체 물리성에서 갓의 강도와 취성이 대조품종보다 강했고, 저장성은 판매가능기간으로 볼 때 34일로 대조품종에 비하여 5일 길었다.

RAW 264.7 세포에서 Nrf2/MAPK 의 활성을 통한 HO-1 과발현에 의한 silymarin의 항산화 효과 (Enhanced Antioxidative Potential by Silymarin Treatment through the Inductionof Nrf2/MAPK Mediated HO-1 Signaling Pathway in RAW 264.7 Cells)

  • 윤현서;안현;박충무
    • 생명과학회지
    • /
    • 제33권10호
    • /
    • pp.776-782
    • /
    • 2023
  • Silymarin은 간 보호, 항산화, 항염, 항암 등 다양한 생리 활성을 나타내는 것으로 보고되었고, 본 연구에서는 산화 스트레스에 대한 항산화 잠재력과 그 기전을 세포 생존력 및 활성산소종 생성 분석과 Western blot 분석을 통해 RAW 264.7 세포에서 알아보고자 하였다. Silymarin은 세포 독성 없이 lipopolysaccharide(LPS)에 의해 자극된 세포 내 활성산소종을 농도 의존적으로 소거하였다. 그리고 항산화 효과를 보여주는 것으로 알려진 제2상 효소 중 하나인 heme oxygenase (HO)-1의 발현은 silymarin 처리에 의해 강하게 유도되었다. 또한 silymarin 처리는 항산화 효소의 전사인자인 nuclear factor-erythroid 2 p45-related factor (Nrf)-2의 발현을 유의미하게 유도하였고, 이는 HO-1 발현증가와 일치하였다. 세포내 산화와 환원 항상성 조절과 관련된 신호 전달물질인 mitogen activated protein kinase (MAPK)와 phosphoinositde 3-kinase (PI3K)의 인산화 정도 또한 Western blot으로 분석하였고, 그 결과 silymarin 은 p38 MAPK 인산화에 의해 HO-1 발현을 유도하는 것으로 나타났다. 그리고 tert-butyl hydroperoxide (t-BHP)를 이용하여 세포내 지질 과산화를 유도함으로써 silymarin에 의해 유도된 HO-1의 항산화 효과를 확인하였다. 그 결과 silymarin 처리에 의해 세포사멸이 유의적으로 억제되었고, p38의 선택적 저해제를 처리한 세포군에서는 t-BHP에 의해 유의적인 세포사멸이 발생하였다. 이 결과를 통해 silymarin은 Nrf-2/p38 MAPK 신호 전달 경로를 통해 HO-1의 발현을 유도하고, 이를 통해 항산화 효과를 높이는 것을 확인할 수 있었다.

Rodgersia podophylla Leaves Suppress Inflammatory mediators through activation of Nrf2/HO-1 signaling, and inhibition of LPS-induced NF-κB and MAPKs signaling in RAW264.7 cells

  • Kim, Ha Na;Kim, Jeong Dong;Park, Su Bin;Jeong, Jin Boo
    • 한국자원식물학회:학술대회논문집
    • /
    • 한국자원식물학회 2019년도 춘계학술대회
    • /
    • pp.94-94
    • /
    • 2019
  • In this study, we elucidated the anti-inflammatory mechanisms of leaves extracts from Rodgersia podophylla (RPL) in RAW264.7 cells. RP-L significantly inhibited the production of the proinflammatory mediators such as NO, iNOS, IL-$1{\beta}$ and IL-6 in LPS-stimulated RAW264.7 cells. RPL increased HO-1 expression in RAW264.7 cells, and the inhibition of HO-1 by ZnPP reduced the inhibitory effect of RPL against LPS-induced NO production in RAW264.7 cells. Inhibition of p38, ROS and $GSK3{\beta}$ attenuated RPL-mediated HO-1 expression. Inhibition of ROS inhibited p38 phosphorylation and $GSK3{\beta}$ expression induced by RPL. In addition, inhibition of $GSK3{\beta}$ blocked RPL-mediated p38 phosphorylation. RPL induced nuclear accumulation of Nrf2, and Inhibition of p38, ROS and $GSK3{\beta}$ abolished RPL-mediated nuclear accumulation of Nrf2. Furthermore, RPL blocked LPS-induced degradation of $I{\kappa}B-{\alpha}$ and nuclear accumulation of p65. RP-L also attenuated LPS-induced phosphorylation of ERK1/2 and p38. Our results suggest that RPL exerts potential antiinflammatory activity by activating ROS/$GSK3{\beta}$/p38/Nrf2/HO-1 signaling and inhibiting NF-${\kappa}B$ and MAPK signaling in RAW264.7 cells. These findings suggest that RPL may have great potential for the development of anti-inflammatory drug.

  • PDF

Investigation of Forage Characteristics of Three Very Early-Maturing Italian Ryegrass (Lolium multiflorum Lam.)

  • Song, Yowook;Woo, Jae Hoon;Lee, Sang-Hoon;Choi, Bo Ram;Lim, Eun A;Lee, Ki-Won
    • 한국초지조사료학회지
    • /
    • 제42권3호
    • /
    • pp.188-194
    • /
    • 2022
  • This study was conducted to investigate the forage characteristics of very early-maturing Italian ryegrass (IRG) three cultivars within September, 2021 to July, 2022 in Cheonan, Korea. We used three different cultivars of Italian ryegrass in this study "Greenfarm" "Greenfarm2ho" and "Greenfarm3ho" The results of heading date in this study, "Greenfarm" was recorded 3 days earlier than the other two cultivars, and its lodge tolerance score was the highest among the three. However, in case of plant length, there was no significantly difference in whole cultivars, in addition disease resistance, insect resistance and cold tolerance were not significantly different in three cultivars. The forage productivity of "Greenfarm2ho" was recorded the highest, especially the 1st harvesting of "Greenfarm2ho" yielded significantly the highest and superior to other varieties. As a result of feed value analysis, three cultivars were generally superior to overseas varieties and in particular, "Greenfarm2ho" was recorded to have excellent value because of the lowest NDF and ADF content. On the other hand, there was no significant difference in crude protein content among three varieties. In case of the monosaccharides content "Greenfarm3ho" had significantly higher glucose content than other two varieties, therefore the "Greenfarm" has advantage for preparing high quality of silage. In contrast, there was no significant difference among three varieties in fructose content.

好袖의 名稱 (A Study on the Name of Ho-Su(好袖))

  • 김진구
    • 복식문화연구
    • /
    • 제7권3호
    • /
    • pp.17-21
    • /
    • 1999
  • The purpose of this study was to trace and identify the word, ho-su(好袖), appeared in Sejosillok(世祖實錄). The results of this research can be summerized as follow : the word, ho-su(好袖) was one of the names of sleeves of so-o-sa(小 子). The ho-su(好袖)is a kind of round sleeves with small wrists. The ho-su(好袖) was a synomym of hak-su(鶴袖). The word, ho-su(好袖)is Korean transliteration of ho-su(好袖). Although the first characters of ho-su(好袖) and ho-su(胡袖) are different from each other in Korean, the sounds and the meanings of these two words are the same. Ho-su(好袖), ho-su(胡袖), and hak-su 鶴袖are synonyms.

  • PDF