• Title, Summary, Keyword: NO

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A Study on the Reduction of Nitric Oxide Molecule (NO) to Nitroxyl Anion (NO-) by Vibrational Energy (진동에너지에 의한 산화질소 분자(NO)의 음이온(NO-)으로의 환원반응에 관한 연구)

  • Cho, Seon-Woog
    • Journal of the Korean Chemical Society
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    • v.46 no.1
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    • pp.14-18
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    • 2002
  • It is shown that one-electron reduction of nitric oxide (NO) to nitroxyl anion $(NO^-)$ can be accelerated by vibrational energy. Potential energy surfaces of NO and $NO^-$ reveal that the vertical transition between them has favorable energetics for vibrationally excited molecule. Also, Franck-Condon factors between NO and $NO^-$ vibrational wave functions are calculated. It shows that the number of open channels increases with increased vibrational energy. These results mean that we can control the rate of reduction of NO to $NO^-$ by radiating an appropriate light.

The Removal of NOx by Mediated Electrochemical Oxidation Using Ag(II) As a Mediator (Ag(II)를 매개체로 사용하는 전기화학적 매개산화에 의한 NOx 제거)

  • Lee, Min-Woo;Park, So-Jin;Lee, Kune-Woo;Choi, Wang-Kyu
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.9 no.3
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    • pp.121-129
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    • 2011
  • The effects of the applied current density, the $AgNO_3$ concentration, the scrubbing liquid flow rate and the NO-air mixed gas flow rate on the NO removal efficiency were investigated by using $Ag^{2+}$ mediated electrochemical oxidation (MEO). Results showed that the NO removal efficiency increased with increasing the applied current density. The effect of the $AgNO_3$ concentration on the NO removal efficiency was negligibly small in the concentration of $AgNO_3$ above 0.1 M. When the scrubbing liquid flow rate increased, the NO removal efficiency was gradually increased. On the other hands, the NO removal efficiency decreased with increasing the NO-air mixed gas flow rate. As a result of the treatment of NO-air mixed gas by using the MEO process with the optimum operating condition and the chemical absorption process using 3 M $HNO_3$ solution as a scrubbing liquid, the removal efficiency of NO and $NO_x$ was achieved as 95% and 63%, respectively.

The studies on microbe isolated from the cocoon in Korea. (Isolation and identification of bacteria) (한국산 잠견에서 분리된 미생물에 관한 연구 제 1보 잠견에서 분리된 Bacteria의 분리동정)

  • 이상원;이철준
    • Journal of Sericultural and Entomological Science
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    • v.7
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    • pp.53-63
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    • 1967
  • In order to identify the bacteria living on the cocoons in Korea, the isolated bacterias' morphological. cultural and physiological characters has been determined through the detailed study. The second aim of this experiment was to protect against the bacteria which damage silk protein during storage. 1. The twelve strains of the bacteria were isolated and identified in the cocoons produced in Korea. The results of the identification are as the following. No 1, No 8; Bacillus subtilis variation No 2, ; Bacillus stearothermophilus No 3, ; Bacillus circulans No 5, No 6; Bacillus thuringiensis No 7, No 11; Bacillus brevis No 12, No l0; Bacillus cereus variation

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Control Oriented Storage and Reduction Modeling of the Lean NOx Trap Catalyst (제어를 위한 Lean NOx Trap의 흡장 및 환원 모델링)

  • Lee, Byoungsoo;Han, Manbae
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.2
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    • pp.60-66
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    • 2014
  • A control oriented model of the Lean $NO_x$ trap (LNT) was developed to determine the timing of $NO_x$ regeneration. The LNT model consists of $NO_x$ storage and reduction model. Once $NO_x$ is stored ($NO_x$ storage model), at the right timing $NO_x$ should be released and then reduced ($NO_x$ reduction model) with reductants on the catalyst active sites, called regeneration. The $NO_x$ storage model simulates the degree of stored $NO_x$ in the LNT. It is structured by an instantaneous $NO_x$ storage efficiency and the $NO_x$ storage capacity model. The $NO_x$ storge capacity model was modeled to have a Gaussian distribution with a function of exhaust gas temperature. $NO_x$ release and reduction reactions for the $NO_x$ reduction model were modeled as Arrhenius equations. The parameter identification was optimally performed by the data of the bench flow reactor test results at space velocity 50,000/hr, 80,000/hr, and temperature of $250-500^{\circ}C$. The LNT model state, storage fraction indicates the degree of stored $NO_x$ in the LNT and thus, the timing of the regeneration can be determined based on it. For practical purpose, this model will be verified more completely by engine test data which simulate the NEDC transient mode.

Involvement of Peroxynitrite in NO Donor-Induced HO-1 Expression in Rat Articular Chondrocytes (흰쥐 관절연골세포에서 NO donor에 의해 유도된 HO-1 발현에서 peroxynitrite의 관련성 연구)

  • Song, Ju-Dong;Kim, Kang-Mi;Kim, Jong-Min;Yoo, Young-Hyun;Park, Young-Chul
    • Journal of Life Science
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    • v.21 no.4
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    • pp.486-493
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    • 2011
  • Nitric oxide (NO) donors are a potent inducer of heme oxygenase-1 (HO-1). However, it is unclear whether or not HO-1 expression induced by NO donors is a direct consequence of NO released by NO donors. Here, we investigated the effects of NO donors on the expression of HO-1 in primary rat articular chondrocytes. NO donors (SIN-1, SNAP, and SNP) significantly induced the accumulation of HO-1 protein accompanied by an increase in HO-1 mRNA. NO donor-induced HO-1 expression exerted cytoprotection against NO and/or superoxide-induced cell death. Guanylate cyclase signaling was not associated with Nrf2 and HO-1 expression in NO donor-treated chondrocytes. Interestingly, NO scavenger carboxy-PTIO and SOD mimetic TEMPOL markedly inhibited NO donor-induced HO-1 expression in chondrocytes. In addition, NO donor-induced HO-1 expression was completely abrogated by the peroxynitrite scavenger MnTBAP. Since peroxynitrite can be physiologcally formed in the cell through reaction of NO with superoxide, we analyzed whether or not peroxynitrite could directly induce HO-1 expression in chondrocytes. Peroxynitrite treatment in chondrocytes evoked doseand time-dependent Nrf2 and HO-1 expression. These results indicate that HO-1 expression induced by NO donors in rat articular chondrocytes is due to NO-mediated peroxynitrite rather than NO.

A Study on the Improvement of Pasture Productivity in a horse grazing low productive pasture (말방목 부실초지의 목초생산성 향상 연구)

  • Kim, Young Jin;Song, Sang Taek;Hwang, Kyung Jun;Kim, Si Hyun;Park, Nam Gun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.38 no.4
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    • pp.266-272
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    • 2018
  • In this study, we created grassland establishment(paddock No.39), grassland improvement(Paddock No.44), and tall fescue seeding(paddock No.64), and the rate botanical composition, DM yield, nutritive value were examined through 2016 to 2017. The rate of botanical composition was 81% in 2016, 75% in 2017, up to 21% higher than No.39 67%, 60%, No.44 58% and 54%. The annual average DM yield was the highest at 13,234kg/ha in the district, followed by No.39, No.44, followed by 10,636kg/ha and 10,235kg/ha, respectively. The crude protein content was the highest at No.39 12.16%, with No.44 and No.64 showing 10.7%, respectively. NDF content (average for two years) was 55.90% in No.44 and No.39, slightly lower than 58.42% and 57.00%, respectively. The two-year ADF average content was 31.07% for the same trend as the NDF capacity in the No.44, below 31.71% and 32.65%, respectively. To sum up the results, Although there was a high level of incentive sowing plot(No.39) in nutritive value, considering the botanical composition and productivity of the pasture, it is also deemed desirable to have a tall fescue plot(No.64).

Modeling of $NH_3$-SCR Diesel $NO_x$ Reduction and Effects of $NO_2/NO_x,\;NH_3$/NO Ratios on the De-$NO_x$ Efficiency ($NH_3$-SCR 방법에 의한 디젤기관의 $NO_x$ 저감과정의 모델링 및 $NO_2/NO_x,\;NH_3$/NO비에 따른 저감효율 변화 해석)

  • Jung, Seung-Chai;Yoon, Woong-Sup
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.3
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    • pp.179-187
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    • 2008
  • A mathematical modeling of $NO_x$ reduction in $NH_3$-SCR process is conducted. The present deterministic model solves one-dimensional conservation equations of mass and species concentrations for channel flows and the catalytic reaction. NO and NO_2$ reactions by the vanadium catalyst in the presence of $NH_3$ are calculated with the rate expressions of Langmuir-Hinshelwood scheme. The modeling was validated with extensive empirical data regarding $NO_x$ reduction efficiency. Analysis of De-$NO_x$ sensitivity conducted with regard to oxygen and water yielded highly accurate prediction over a wide range of $NO_2/NO_x$ ratios from 0 to 1 in a temperature range of $200^{\circ}C{\sim}550^{\circ}C$. The $NO_x$ reduction largely depends on $NO_2/NO_x$ ratio at temperatures lower than $300^{\circ}C$. NO reduction efficiency is significantly augmented with increasing in $NH_3$/NO ratio at higher temperatures, whereas rather insensitive to the $NH_3$/NO ratio at lower temperatures.

Kernel Characteristics of the Modified Opaque-2 Systhetics, Zea mays, L. (변갱 오페이크-2 옥수수의 종실특성)

  • Bong-Ho Chae
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.31 no.1
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    • pp.49-55
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    • 1986
  • To obtain basic information required for improving grain yield of the two modified opaque-2 synthetics, which have been developed at College of Agr., Chungnam National Univ. in 1980 and named as Puyo No.2 and No.3, physical kernel characteristics of the two synthetics were fully investigated and results obtained are as follows: Puyo No.2 synthetics had a smaller kernel size with lighter weight than the Puyo No.3. The Puyo No.2 synthetics had higher kernel density than the Puyo No.3 with large Kernel size. The Puyo No.2 had kernels with heterogenous endosperm phenotypes. Some kernels had mottled patches on endosperm, while other kernels 1/2 and 1/2 phenotypes. All the modified opaque-2 synthetics had somewhat lighter endosperm weight than the normal check hybrid. The Puyo No.2 synthetics with smaller kernel size had more germ portion compared with large kernel, Puyo No.3. The Puyo No.2 had shown also typical endosperm texture when observed under microscope after cutting by glass knife. The lysine content of the Puyo No.2 was higher than those of other varieties studied. Breeding schemes to improve the yield capacity of the two modified opaue-2 synthetics were discussed.

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Experimental Study on the NO2/NOX Ratio from Exhaust of Diesel Vehicles by Chassis Dynamometer (경유자동차에서 배출되는 NO2/NOX 비율 특성)

  • KIM, SUNMOON;KIM, JOUNGHWA;JUNG, SUNGWOON;SUNG, KIJAE;KIM, JEONGSOO;KIM, INGU
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.2
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    • pp.220-224
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    • 2017
  • Nitrogen dioxide ($NO_2$) is an important urban pollutant in Korea. Expecially, diesel vehicles are responsible for the most traffic rated nitrogen oxide ($NO_X$) emission, including nitric oxide (NO) and nitrogen dioxide ($NO_2$). Though nitrogen oxide ($NO_X$) emission from vehicle was applied a strict enforcement of emission standard, the specific $NO_2$ fraction in $NO_X$ ($NO_2/NO_X$) from various types of diesel vehicles was not understood. In order to investigate the fraction of $NO_2/NO_X$, the vehicle emission study was carried out at the facility of Transport Pollution Research Center (TPRC), National Institute of Environmental Research (NIER), Korea. Three different types of diesel vehicles(VAN, SUV, passenger) were tested on the NIER driving mode. The result of $NO_2/NO_X$ ratio was over 0.1 for all test vehicles and the highest $NO_2$ emission was observed at the van vehicle. The observation was showed that the emission trend of $NO_2/NO_X$ for passenger and SUV vehicles were inversely proportional. Also, as the emission standard has been strengthen, the emission rate of $NO_2$ has been decrease.

$NO_x$ Chemistry Over Rutile $TiO_2$(110) Surfaces

  • Kim, Yu-Gwon
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.131-131
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    • 2012
  • We present our recent temperature-programmed desorption (TPD) study on catalytic reductions of $NO_x$ such as NO, $NO_2$, and $N_2O$ over rutile $TiO_2$(110) surfaces. Our results indicate that $NO_2$/NO readily reacts to give NO/$N_2O$ desorption at the substrate temperature as low as 100 K/70 K. Interestingly, $N_2O$, however, does not dissociate into $N_2$ and $O_{BBO}$ over the oxygen vacancy on the $TiO_2$(110) surface. Successive reduction of NO and $NO_2$ into $N_2O$ and NO, respectively, leaves oxygen atoms on the $TiO_2$(110) surface in a form of $O_{ad}$, which can induce additional reductive channels of NO and $NO_2$ at higher temperatures up to 400 K. During the repeated TPD cycles of $NO_x$, our x-ray photoelectron spectroscopy (XPS) analysis indicates that no N atom accumulates on the $TiO_2$ surface.

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