• Title/Summary/Keyword: oxidation/reduction potential

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Presalting Condition Effects on the Development of Pink Color in Cooked Ground Chicken Breasts

  • Bae, Su Min;Cho, Min Guk;Jeong, Jong Youn
    • Food Science of Animal Resources
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    • v.40 no.2
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    • pp.197-208
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    • 2020
  • The effects of presalting conditions (storage temperature and duration) with/without sodium tripolyphosphate (STPP) on the color and pigment characteristics of cooked ground chicken breast were investigated. Meat mixtures containing 2% NaCl (control) or 2% NaCl and 0.5% STPP (STPP treatment) were stored for 0, 3, 5, 7, and 10 d at 2℃ or 7℃, followed by cooking to 75℃, and cooling and storage at 2℃-3℃ until further analysis. The treatment was the most effective on the pink color defect of all independent variables. The effect of storage temperature was only observed on CIE L values and percentage myoglobin denaturation (PMD). The control was redder than the STPP treated samples and the CIE a values increased (p<0.05) from 0 to 5 d in the control and STPP treated samples. Compared to the STPP treatment, the control exhibited increased reducing conditions (more negative oxidation reduction potential), lower undenatured myoglobin, and greater PMD. No differences in the cooking yields of the control and STPP-treated samples were observed for various storage durations. Products with STPP showed higher (p<0.05) pH values than those without STPP, but no differences (p>0.05) in PMD were observed over the storage period in the control and STPP treated samples, except for day 0. Thus, STPP is effective at reducing the pink color in cooked chicken breasts. In addition, presalting for longer than 5 d resulted in increased pink color of the cooked chicken breasts.

Preparation and Characteristics of Li/$V_6O_{13}$ Secondary Battery (Li/$V_6O_{13}$ 2차전지의 제조 및 특성)

  • Moon, S.I.;Jeong, E.D.;Doh, C.H.;Yun, M.S.;Yum, D.H.;Chung, M.Y.;Park, C.J.;Youn, S.K.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.11a
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    • pp.136-140
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    • 1992
  • The purpose of this research is to develop the lithium secondary battery. This paper describes the preparation, electrochemical properties of nontstoichiometric(NS)-$V_6O_{13}$ and characteristics of Li/$V_6O_{13}$ secondary battery. NS-$V_6O_{13}$ was prepared by thermal decomposition of $NH_4VO_3$ under Ar stream of 140ml/min~180ml/min flow rate. And then, this NS-$V_6O_{13}$ was used for cathode active material. Cathode sheet was prepared by compressing the composite of NS-$V_6O_{13}$, acetylene black(A.B) and teflon emulsion (T.E). Characteristics of the test cell are summarised as follows. Oxidation capacity of NS-$V_6O_{13}$ was about 20% less than its reduction capacity. A part of NS-$V_6O_{13}$ cathode active material showed irreversible reaction in early charge-discharge cycle. This phenomena seems to be caused by irreversible incoporation/discoporation of lithium cation to/from NS-$V_6O_{13}$ host. Discharge characteristics curve of Li/$V_6O_{13}$ cell showed 4 potential plateaus. Charge-discharge capacity was declined in the beginning of cycling and slowly increased in company with increasing of coulombic efficiency. Energy density per weight of $V_6O_{13}$ cathode material was as high as 522Wh/kg~765Wh/kg.

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Charge/discharge Properties of $V_{6}O_{13}$ Composite/Li Cell with Solid Polymer Electrolyte (고체 고분자 전해질을 사용한 $V_{6}O_{13}$ Composite/Li Cell의 충방전 특성)

  • Kim, J.U.;Yu, Y.H.;Jeong, I.S.;Park, B.K.;Gu, H.B.;Moon, S.I.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1414-1417
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    • 1996
  • The purpose of this study Is to research and develop $V_{6}O_{13}$ composite cathode for lithium thin film battery. $V_{6}O_{13}$ represents a class of cathode active material used in Li rechargeable batteries. In this study, we investigated cyclic voltammetry and charge/discharge characteristics of $V_6O_{13}$/SPE/Li cells. Cyclic voltammogram of $V_{6}O_{13}$/SPE/Li cell at scan rate 1mV/sec showed reduction peaks of 2.25V and 2.4V and oxidation peaks of 2.4V and 2.2V. The discharge curve of $V_{6}O_{13}$/SPE/Li cell showed 4 potential plateaus. The discharge capacity was decreased in the beginning of charge/discharge cycling. After 8th cycling, the discharge capacity was stable. The discharge capacity of 1st cycle and 15th cycle was 290mAh/g and 147mAh/g at $25^{\circ}C$, respectively.

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A Study on Si-wafer Cleaning by Electrolyzed Water (전리수를 이용한 실리콘 웨이퍼 세정)

  • Yun, Hyo-Seop;Ryu, Geun-Geol
    • Korean Journal of Materials Research
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    • v.11 no.4
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    • pp.251-257
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    • 2001
  • A present semiconductor cleaning technology is based upon RCA cleaning, high temperature process which consumes vast chemicals and ultra Pure water(UPW). This technology gives rise to the many environmental issues, therefore some alternatives have been studied. In this study, intentionally contaminated Si wafers were cleaned using the electrolyzed water(EW). The EW was generated by an electrolysis equipment which was composed of anode. cathode, and toddle chambers. Oxidative water and reductive water were obtained in anode and cathode chambers, respectively. In case $NH_4$Cl electrolyte, the oxidation-reduction potential(ORP) and pH for anode water(AW) and cathode water(CW) were measured to be +1050mV and 4.7, and -750mV and 9.8, respectively. For cleaning metallic impurities, AW was confirmed to be more effective than that of CW, and the particle distribution after various particle removal processes was shown to be same distribution.

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Isolation, Characterization, and Use for Plant Growth Promotion Under Salt Stress, of ACC Deaminase-Producing Halotolerant Bacteria Derived from Coastal Soil

  • Siddikee, M.A.;Chauhan, P.S.;Anandham, R.;Han, Gwang-Hyun;Sa, Tong-Min
    • Journal of Microbiology and Biotechnology
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    • v.20 no.11
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    • pp.1577-1584
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    • 2010
  • In total, 140 halotolerant bacterial strains were isolated from both the soil of barren fields and the rhizosphere of six naturally growing halophytic plants in the vicinity of the Yellow Sea, near the city of Incheon in the Republic of Korea. All of these strains were characterized for multiple plant growth promoting traits, such as the production of indole acetic acid (IAA), nitrogen fixation, phosphorus (P) and zinc (Zn) solubilization, thiosulfate ($S_2O_3$) oxidation, the production of ammonia ($NH_3$), and the production of extracellular hydrolytic enzymes such as protease, chitinase, pectinase, cellulase, and lipase under in vitro conditions. From the original 140 strains tested, on the basis of the latter tests for plant growth promotional activity, 36 were selected for further examination. These 36 halotolerant bacterial strains were then tested for 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Twenty-five of these were found to be positive, and to be exhibiting significantly varying levels of activity. 16S rRNA gene sequencing analyses of the 36 halotolerant strains showed that they belong to 10 different bacterial genera: Bacillus, Brevibacterium, Planococcus, Zhihengliuella, Halomonas, Exiguobacterium, Oceanimonas, Corynebacterium, Arthrobacter, and Micrococcus. Inoculation of the 14 halotolerant bacterial strains to ameliorate salt stress (150 mM NaCl) in canola plants produced an increase in root length of between 5.2% and 47.8%, and dry weight of between 16.2% and 43%, in comparison with the uninoculated positive controls. In particular, three of the bacteria, Brevibacterium epidermidis RS15, Micrococcus yunnanensis RS222, and Bacillus aryabhattai RS341, all showed more than 40% increase in root elongation and dry weight when compared with uninoculated salt-stressed canola seedlings. These results indicate that certain halotolerant bacteria, isolated from coastal soils, have a real potential to enhance plant growth under saline stress, through the reduction of ethylene production via ACC deaminase activity.

Nitrogen and Phosphorus Removal in Domestic Wastewater using SBR Process with Flow Changing Continuous Feed and Cyclic Draw (교대연속유입식 SBR 공정을 이용한 하수중의 질소 및 인 제거)

  • Seo, In-seok;Kim, Hong-suck;Kim, Youn-kwon;Kim, Ji-yeon
    • Journal of Korean Society on Water Environment
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    • v.22 no.2
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    • pp.203-208
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    • 2006
  • A continuous feed and cyclic draw SBR process was developed to overcome flow rate fluctuation and to maximize organic matters utilization efficiency for nitrogen and phosphorus removal. The developed SBR process was operated with two parallel reactors. Influent was supplied to one reactor which was not obligately aerated. At the same time, the other reactor was just aerated without supplying influent. In addition this mode was changed periodically. Cycle time was 6hr and aeration time ratio($t_{aer}/t_{total}$) was 0.33, respectively. $COD_{cr}$ and SS removal efficiencies of 95% or higher were achieved. Nitrogen removal was so greatly influenced by influent $COD_{cr}/T-N$ ratio. At influent $COD_{cr}/T-N$ ratio of 5.7, removal efficiencies of ammonia-N, T-N and T-P were 96%, 78% and 55%, respectively. Influent $COD_{cr}/T-N$ of 4 or higher ratio was necessary to achieve 60% or higher nitrogen removal. Organic matters of influent was efficiently utilized in denitrification reaction and consumed COD has a good correlation with removed T-N(about 6.5 mgCOD/mgTN). Continuous feed and cyclic draw SBR process could be one of alternative processes for the removal of nutrients in rural area where $COD_{cr}/T-N$ ratio was low and fluctuation of flow rate was severe.

Reduced Graphene Oxide Field-effect Transistor as a Transducer for Ion Sensing Application

  • Nguyen, T.N.T.;Tien, Nguyen Thanh;Trung, Tran Quang;Lee, N.E.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.562-562
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    • 2012
  • Recently, graphene and graphene-based materials such as graphene oxide (GO) or reduced graphene oxide (R-GO) draws a great attention for electronic devices due to their structures of one atomic layer of carbon hexagon that have excellent mechanical, electrical, thermal, optical properties and very high specific surface area that can be high potential for chemical functionalization. R-GO is a promising candidate because it can be prepared with low-cost from solution process by chemical oxidation and exfoliation using strong acids and oxidants to produce graphene oxide (GO) and its subsequent reduction. R-GO has been used as semiconductor or conductor materials as well as sensing layer for bio-molecules or ions. In this work, reduced graphene oxide field-effect transistor (R-GO FET) has been fabricated with ITO extended gate structure that has sensing area on ITO extended gate part. R-GO FET device was encapsulated by tetratetracontane (TTC) layer using thermal evaporation. A thermal annealing process was carried out at $140^{\circ}C$ for 4 hours in the same thermal vacuum chamber to remove defects in R-GO film before deposition of TTC at $50^{\circ}C$ with thickness of 200 nm. As a result of this process, R-GO FET device has a very high stability and durability for months to serve as a transducer for sensing applications.

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Mathematical Approach for Environmental Impact Analysis of Soils from Abandoned Mines (폐광산주변 토양의 환경영향해석을 위한 수학적 접근)

  • Kim, Kwang-Tae;Kang, Mee-A
    • The Journal of Engineering Geology
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    • v.18 no.3
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    • pp.297-302
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    • 2008
  • The main reason of the pollution caused by soils and tailings located at discussed mines is heavy metals and AMD(acid mine drainage). Human health is affected by these pollutants which are spreaded from the abandoned mines. In this study, we try a mathematical approach to predict the pollution level of heavy metals caused by the surrounding soils of abandoned mines. The new approach is established with the correlation between the distance and pH, ORP. The change of pH and ORP can be described by the rate of initial values to experimental values. We demonstrate a realistic possibility of the mathematical approach to assess an environmental impact from disused mines cause the rate range is 0.95 to 1.03 for 60 days. Therefore our proposed approach will be useful as a few promising method for the management of heavy metals in many mines.

Characteristics of Seaweed Salts Prepared with Various Seaweeds (해조소금의 성분 특성에 관한 연구)

  • Kim, Dong-Han;Rhim, Jong-Whan;Lee, Sang-Bok
    • Korean Journal of Food Science and Technology
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    • v.35 no.1
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    • pp.62-66
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    • 2003
  • Physicochemical properties and mineral compositions of seaweed salts prepared with various seaweeds and concentrated sea water were determined. Ash content of sea mustard was highest (22.7%) and that of laver the lowest (9.8%). Sea mustard contained high amount of Na, while sea tangle and seaweed fusiforme contained high amounts of K and Ca. When insoluble solids were removed after incineration of dried salt, surface color of the salt whitened more due to increase in salt purity with resulting decreases in pH and oxidation-reduction potential (ORP), pH and ORP of the ashed salt decreased, and K and Ca contents increased, while Mg content decreased. Yield of seaweed salt was the highest in sea mustard, ORP was lowest in sea tangle and seaweed fusiforme, and K and Ca contents increased significantly in sea tangle and seaweed fusiforme salts. As the concentration of sea water increased, yield and purity of the salts increased with decrease in pH and ORP and increase in Ca and Mg contents. Seaweed salt showed the characteristic crystalline structure as viewed by SEM.

Effect of Anti-Microbial Materials on Storages of Ssamjang (항균물질 첨가에 의한 쌈장의 저장중 품질특성)

  • Kang, Bo-Ra;Im, Go-Eun;Kim, Dong-Han
    • Journal of Applied Biological Chemistry
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    • v.56 no.1
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    • pp.11-17
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    • 2013
  • The effect of additives on the quality of ssamjang was investigated during storage. The L-, a- and b-values of ssamjang decreased gradually during storage, and the total color difference (${\Delta}E$) increased in the control group. The gas production of ssamjang was reduced in K-sorbate, alcohol and mustard added groups. The number of yeast increased rapidly up to 6 weeks of storage, then decreased in the mustard, alcohol, and K-sorbate added groups. The oxidation-reduction potential and water activity decreased until 6 weeks and 12 weeks, respectively, and then increased gradually. Titratable acidity increased with concomitant decrease in pH, however, it increased slightly in the K-sorbate and ethanol added groups. Reducing sugar content increased until 9 weeks of storage, except the turmeric added group. Alcohol content increased until 15 weeks in the Japanese apricot juice, and turmeric added group. The sensory test result for the taste, flavor and overall acceptability showed that mustard added ssamjang was more acceptable than other groups.