• Title/Summary/Keyword: Secondary oxidation

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Effects of Steam Sources and Glycerol on the Storage Stability of Fish Oil (탈취공정 중 steam source의 조절과 glycerol 첨가가 어유의 저장안정성에 미치는 영향)

  • Yi, Ock-Sook;Han, Dae-Seok;Cho, Dong-Wuk
    • Korean Journal of Food Science and Technology
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    • v.26 no.6
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    • pp.824-827
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    • 1994
  • Sardine oil was vacuum-steam deodorized at $170^{\circ}C$ with acid (acetic and citric acid) and ethanol solution as steam sources. Glycerol was added to fish oil to remove volatile odorous constituents. The storage stability of deodorized fish oil was determined by totox value, secondary parameter obtained from peroxide and anisidine values. Both deodorization with acetic acid solution and addition of glycerol to the oil resulted in improved storage stability. The totox values of fish oil deodorized with water, glycerol+water and glycerol+acetic acid solution were 936, 611, and 443, respectively after 10 days at $30^{\circ}C$. The result showed that acetic acid seemed to destroy the odorous constituents and glycerol accelerated the removal of odorous constituents, such as amines in fish oil.

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Effects of Morindae Officinalis Radix on the Spermatogenesis and Antioxidant Activities in the SD Rat

  • Choi Eun Mi;Cho Jung Hoon;Jang Jun Bock;Lee Kyung Sub
    • The Journal of Korean Medicine
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    • v.26 no.4
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    • pp.31-38
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    • 2005
  • Objectives: This study was conducted to investigate the effects of Morindae officinalis Radix (巴戟) on the spermatogenesis and antioxidant activities in the Sprague Dawley (SD) rat. Materials and Methods: We choose the 2-month-old SD rats, and administered the extract powder of Morindae officinalis Radix once in a day for 28 days. The control rats were administered normal water in the same way and duration. We observed changes of body weight, surgically isolated testis, epididymis, vascular gland and prostate gland before and after administration of Morindae officinalis Radix extracts in SD Rats. Also we compared the testicular tissue, especially seminiferous tubules between the control and treated groups by histochemical methods. In addition, we examined the total, normal, morphologic and motile sperm in the cauda epididymis, and the activity of catalase and peroxidase in the isolated testis tissue. Results: There was no significant difference between control and treatment groups in the body weight, testis, vascular and prostate gland, but the weight of epididymis showed significant difference in the control group. The concentration of total sperm, the motility and normality of spermatozoa was significantly different when compared with the control group, respectively. In the histological examination of testicular tissues, the tendency of increasement of angiogenesis between seminiferous tubules was observed. And the concentration of spermatogonia, primary and secondary spermatocyte and sperm were higher than that of control testicular tissues. Finally, the activity of catalase and peroxidase related inhibitory molecules of oxidation were slightly increased in the treatment group than those of control group. Conclusions: This study shows that Morindae officinalis Radix has the beneficial effect on the concentration, morphology and motility of sperm, the important factor in male fertility. We can suggest that Morindae officinalis Radix has an effect on the spermatogenesis in the SD rat.

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Development and Application of the Backward-tracking Model Analyzer to Track Physical and Chemical Processes of Air Parcels during the Transport (대기오염물질의 이동경로상 물리화학적 변화 추적을 위한 Backward-tracking Model Analyzer 방법론 마련)

  • Bae, Minah;Kim, Hyun Cheol;Kim, Byeong-Uk;Kim, Soontae
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.3
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    • pp.217-232
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    • 2017
  • An Eulerian-Lagrangian hybrid modeling system to analyze physical and chemical processes during the transport of air parcels was developed. The Backward-tracking Model Analyzer (BMA) was designed to take advantages of both Eulerian and Lagrangian modeling approaches. Simulated trajectories from the National Oceanic and Atmospheric Administration HYSPLIT model were combined with the US Environmental Protection Agency Community Multi-scale Air Quality (CMAQ)-simulated concentrations and additional diagnostic analyses. In this study, we first introduced a generalized methodology to seamlessly match polylines (HYSPLIT) and threedimensional polygons (CMAQ), which enables mass-conservative analyses of physio-chemical processes of transporting air parcels. Two applications of the BMA were conducted: (1) a long-range transport case of pollutant plume across the Yellow Sea using CMAQ Integrated Process Rate analyses, and (2) a domestic circulation of pollutants within (and near) the South Korea based on the sulfate tracking analyzer. The first episode demonstrated a secondary formation of nitrate and ammonium during the transport over the Yellow Sea while sulfate is mostly transported after being formed over the China, and the second episode demonstrated a dominant impact of boundary condition with active sulfate formation from gas-phase oxidation near the Seoul Metropolitan Area.

Deterioration Diagnosis and Petrogenesis for Rock Properties of the Stone Lantern in the Gwanchoksa Temple, Nonsan, Korea (논산 관촉사 석등의 훼손도 진단 및 기원암의 성인적 해석)

  • Lee, Myeong Seong;Yi, Jeong Eun;Pyo, Su Hee;Song, Chi Young;Lee, Chan Hee
    • Journal of Conservation Science
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    • v.17 s.17
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    • pp.5-18
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    • 2005
  • Rock materials of the Stone Lantern in the Gwanchoksa temple was composed of dark grey granodiorite. This Stone Lantern is partly structural distortion as S-shape, especially, rocks of the upper supports and under the roof materials were highly deterioration due to the surface exfoliation, and strong secondary contaminations owing to the discoloration by oxidation of inserted iron plates between the rock properties, and white grey to dark black contaminants along the rain path way. Rock surface of the Stone Lantern occurred as partly green patches because of coated by algae, lichen and moss. This biological problems are need for cleaning and treatments. The Stone Lantern have to be considered to conservation method that can reduce weathering factors with long-term monitoring about environmental change for structural stability, surface degradation and mechanical weathering. Materials of the Stone Lantern and basement rocks of the area are consisted of same petrogenetic granodiotite based on occurrences, petrological and geochemical characteristics.

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A Bioactive Fraction from Streptomyces sp. Enhances Maize Tolerance against Drought Stress

  • Warrad, Mona;Hassan, Yasser M.;Mohamed, Mahmoud S.M.;Hagagy, Nashwa;Al-Maghrabi, Omar A.;Selim, Samy;Saleh, Ahmed M.;AbdElgawad, Hamada
    • Journal of Microbiology and Biotechnology
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    • v.30 no.8
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    • pp.1156-1168
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    • 2020
  • Drought stress is threatening the growth and productivity of many economical crops. Therefore, it is necessary to establish innovative and efficient approaches for improving crop growth and productivity. Here we investigated the potentials of the cell-free extract of Actinobacteria (Ac) isolated from a semi-arid habitat (Al-Jouf region, Saudi Arabia) to recover the reduction in maize growth and improve the physiological stress tolerance induced by drought. Three Ac isolates were screened for production of secondary metabolites, antioxidant and antimicrobial activities. The isolate Ac3 revealed the highest levels of flavonoids, antioxidant and antimicrobial activities in addition to having abilities to produce siderophores and phytohormones. Based on seed germination experiment, the selected bioactive fraction of Ac3 cell-free extract (F2.7, containing mainly isoquercetin), increased the growth and photosynthesis rate under drought stress. Moreover, F2.7 application significantly alleviated drought stress-induced increases in H2O2, lipid peroxidation (MDA) and protein oxidation (protein carbonyls). It also increased total antioxidant power and molecular antioxidant levels (total ascorbate, glutathione and tocopherols). F2.7 improved the primary metabolism of stressed maize plants; for example, it increased in several individuals of soluble carbohydrates, organic acids, amino acids, and fatty acids. Interestingly, to reduce stress impact, F2.7 accumulated some compatible solutes including total soluble sugars, sucrose and proline. Hence, this comprehensive assessment recommends the potentials of actinobacterial cell-free extract as an alternative ecofriendly approach to improve crop growth and quality under water deficit conditions.

Physico-chemical properties of green leaf volatiles (GLV) for ascertaining atmospheric fate and transport in fog

  • Vempati, Harsha;Vaitilingom, Mickael;Zhang, Zenghui;Liyana-Arachchi, Thilanga P.;Stevens, Christopher S.;Hung, Francisco R.;Valsaraj, Kalliat T.
    • Advances in environmental research
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    • v.7 no.2
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    • pp.139-159
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    • 2018
  • Green Leaf Volatiles (GLVs) is a class of biogenically emitted oxygenated hydrocarbons that have been identified as a potential source of Secondary Organic Aerosols (SOA) via aqueous oxidation. The physico-chemical properties of GLVs are vital to understanding their fate and transport in the atmosphere via fog processing, but few experimental data are available. We studied the aqueous solubility, 1-octanol/water partition coefficient, and Henry's law constant ($K_H$) of five GLVs at $25^{\circ}C$: methyl jasmonate, methyl salicylate, 2-methyl-3-buten-2-ol, cis-3-hexen-1-ol, and cis-3-hexenyl acetate. Henry's law constant was also measured at temperatures and ionic strengths typical of fog. Experimental values are compared to scarcely-available literature values, as well as estimations using group and bond contribution methods, property-specific correlations and molecular dynamics simulations. From these values, the partition coefficients to the air-water interface were also calculated. The large Henry's law constant of methyl jasmonate ($8091{\pm}1121M{\cdot}atm^{-1}$) made it the most significant GLV for aqueous phase photochemistry. The HENRYWIN program's bond contribution method from the Estimation Programs Interface Suite (EPI Suite) produced the best estimate of the Henry's constant for GLVs. Estimations of 1-octanol/water partition coefficient and solubility are best when correlating an experimental value of one to find the other. Finally, the scavenging efficiency was calculated for each GLV indicating aqueous phase processing will be most important for methyl jasmonate.

Fabrication of Ni-free Fe-based Alloy Nano Powder by Pulsed Wire Evaporation in Liquid: Part I. Effect of Wire Diameter and Applied Voltage (액중 전기선 폭발법에 의한 Ni-free Fe계 나노 합금분말의 제조: 1. 합금 wire의 직경 및 인가 전압의 영향)

  • Ryu, Ho-Jin;Lee, Yong-Heui;Son, Kwang-Ug;Kong, Young-Min;Kim, Jin-Chun;Kim, Byoung-Kee;Yun, Jung-Yeul
    • Journal of Powder Materials
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    • v.18 no.2
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    • pp.105-111
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    • 2011
  • This study investigated the effect of wire diameter and applied voltage on the fabrication of Ni-free Fe-based alloy nano powders by employing the PWE (pulsed wire evaporation) in liquid, for high temperature oxidation-resistant metallic porous body for high temperature particulate matter (or soot) filter system. Three different diameter (0.1, 0.2, and 0.3 mm) of alloy wire and various applied voltages from 0.5 to 3.0 kV were main variables in PWE process, while X-ray diffraction (XRD), field emission scanning microscope (FE-SEM), and transmission electron microscope (TEM) were used to investigate the characteristics of the Fe-Cr-Al nano powders. It was controlled the number of explosion events, since evaporated and condensed nano-particles were coalesced to micron-sized secondary particles, when exceeded to the specific number of explosion events, which were not suitable for metallic porous body preparation. As the diameter of alloy wire increased, the voltage for electrical explosion increased and the size of primary particle decreased.

Composition of Organic Compounds in the Ambient PM10 of the Anmyon Island (안면도 미세먼지 내 유기성분들의 분포 특성)

  • Lee, Ji Yi;Hwang, Eun Jin;Lim, Hyung Bae;Kim, Yu Won;Kim, Eun Sil;Kim, Yong Pyo
    • Particle and aerosol research
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    • v.9 no.3
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    • pp.187-197
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    • 2013
  • To understand the characteristics of organic aerosol(OA) at the background atmosphere of Korea, an observation of atmospheric PM10 was conducted at a Global Atmospheric Watch(GAW) station operated by the Korean Meteorological Administration at Anmyon Island during 2010. Various organic compounds were analyzed from 26 samples by using a gas chromatography-mass spectrometer. Water soluble organic carbon(WSOC) was also analyzed by using a total organic carbon(TOC) analyzer. Among 6 classes with 68 target compounds detected, the classes of n-alkanoic and alkenoic acids ($326.67{\pm}75.40ngm^{-3}$) and dicarboxylic acids ($323.74{\pm}361.89ngm^{-3}$) were found to be major compound classes in the atmosphere of Anmyon Island. Compared to the previous results reported for 2005 spring samples at Gosan site, the concentrations of organic compounds at Anmyon Island were 3-10 times higher than Gosan site due to the difference of location and sampling period. The concentrations of organic compounds were varied with the atmospheric conditions. Significant increase of the concentrations of dicarboxylic and carboxylic acids in the smog episode indicated that secondary oxidation of organic compounds was major factor to increase OA concentration during smog episode in the Anmyon Island. It was found that the compositions of the OA measured at Anmyon Island were dependent on the air parcel trajectories.

Synthesis of Solution-Processed Cu2ZnSnSe4 Thin Films on Transparent Conducting Oxide Glass Substrates

  • Ismail, Agus;Cho, Jin Woo;Park, Se Jin;Hwang, Yun Jeong;Min, Byoung Koun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.7
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    • pp.1985-1988
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    • 2014
  • $Cu_2ZnSnSe_4$ (CZTSe) thin films were synthesized on transparent conducting oxide glass substrates via a simple, non-toxic, and low-cost process using a precursor solution paste. A three-step heating process (oxidation, sulfurization, and selenization) was employed to synthesize a CZTSe thin film as an absorber layer for use in thin-film solar cells. In particular, we focused on the effects of sulfurization conditions on CZTSe film formation. We found that sulfurization at $400^{\circ}C$ involves the formation of secondary phases such as $CuSe_2$ and $Cu_2SnSe_3$, but they gradually disappeared when the temperature was increased. The formed CZTSe thin films showed homogenous and good crystallinity with grain sizes of approximately 600 nm. A solar cell device was tentatively fabricated and showed a power conversion efficiency of 2.2% on an active area of 0.44 $cm^2$ with an open circuit voltage of 365 mV, a short current density of 20.6 $mA/cm^2$, and a fill factor of 28.7%.

Geochemical Study on Pollution of Heavy Metals in Soils, Plants and Streams in the Vicinity of Abandoned Metal Mines -Dalseong and Kyeongsan Mines- (금속폐광산주변의 토양, 식물 및 하천의 중금속오염에 대한 지화학적 연구 -달성 및 경산광산-)

  • Lee, Jae Yeong;Lee, In Ho;Lee, Sun Yeong
    • Economic and Environmental Geology
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    • v.29 no.5
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    • pp.597-613
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    • 1996
  • The tonnage of copper and tungsten produced at Dalseong mine by Taehan Tungsten Mining Company from 1961 to 1971 was 48,704 tons (M/T) of 4 wt.% Cu and 1,620 tons (S/T) of 70wt.% WO, but the mine was closed in 1974. Kyeongsan mine is a small abandoned cobalt mine with no data of production. To investigate the pollution level of the mine areas, soils, plants (Ohwi and Pampanini), stream waters and stream sediments were taken and Fe, Mn, Cu, Pb, Zn, Ni, Co, Cd and Cr were analysed by ICP. Soils are considerably contaminated by the heavy metals related to ore deposits, The heavy metal contents in plants vary with the species and parts of plants. Stream waters are anomalously high in heavy metals in the vicinity of the mines but the contents decrease downstream in the process of dilution and precipiation. However, heavy metal contents increase very high in stream sediments due to precipiation. To protect environmental damages caused by acid mine drainages wetlands must be constructed outside pits, and it is necessary to fill pits with waters, limestone chips and organic materials, which give reducing and alkaline condition to ores. Under the condition pyrite is protected from oxidation and aqueous iron sulphates precipitate to form stable secondary pyrite.

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