• Title/Summary/Keyword: In Situ Degradation

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Study on Roughage Degradation and Adhesion of Rumen Fibrolytic Bacteria by Real-Time PCR (Real-Time PCR 기법을 이용한 반추위 섬유소분해 박테리아의 부착과 조사료 분해에 관한 연구)

  • Sung, Ha Guyn
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.34 no.1
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    • pp.60-67
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    • 2014
  • The comparisons between cellulolytic bacteria adhesion on rice straw and fiber digestion in time course during rumen fermentation were studied in situ. The adhesions of cellulolytic bacteria, F. succinogenes. R. albus and R. flavefaciens, were measured by RT-PCR. When the rice straws were incubated at 0. 2, 4, 8, 12 and 24 hours of the in situ rumen, straw was degraded with increasing speed during the incubation and showed the highest disappearance increasing rate (DM g/h) from 8 to 12 hour. The adhesions of F. succinogenes, R. flavefaciens and R. albus were achieved above 80% in 1 hour of in situ rumen fermentation and then keep adhesive population up after the time of fermentation. When the in situ samples were collected at 0, 5, 10, 30 and 60 min to detect the early stages of adhesion on the rice straws ingested into rumen, the numberous adhesive colony of F. succinogenes, R. flavefaciens and R. albus were detected in 5 min. In case of rice straw treated with 0, 2, 4 and 8% NaOH, all of three cellulolytic bacteria showed the increasing trends of adhesion with increasing DM disappearance of rice straw by higher concentration of NaOH at 12 hour of in situ. However, there were showed respectively difference at 24 hour. The present results gave certain evidence that adhesion of cellulolytic bacteria is definitely achieved in early stage of roughage ingestion into rumen, their colony develop the stable communities on roughage in process of rumen fermentation and then fiber degradation is accelerated.

Technical Investigation into the In-situ Electron Backscatter Diffraction Analysis for the Recrystallization Study on Extra Low Carbon Steels

  • Kim, Ju-Heon;Kim, Dong-Ik;Kim, Jong Seok;Choi, Shi-Hoon;Yi, Kyung-Woo;Oh, Kyu Hwan
    • Applied Microscopy
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    • v.43 no.2
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    • pp.88-97
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    • 2013
  • Technical investigation to figure out the problems arising during in-situ heating electron backscatter diffraction (EBSD) analysis inside scanning electron microscopy (SEM) was carried out. EBSD patterns were successfully acquired up to $830^{\circ}C$ without degradation of EBSD pattern quality in steels. Several technical problems such as image drift and surface microstructure pinning were taking place during in-situ experiments. Image drift problem was successfully prevented in constant current supplying mode. It was revealed that the surface pinning problem was resulted from the $TiO_2$ oxide particle formation during heating inside SEM chamber. Surface pinning phenomenon was fairly reduced by additional platinum and carbon multi-layer coating before in-situ heating experiment, furthermore was perfectly prevented by improvement of vacuum level of SEM chamber via leakage control. Plane view in-situ observation provides better understanding on the overall feature of recrystallization phenomena and cross sectional in-situ observation provides clearer understanding on the recrystallization mechanism.

Electrochemical Degradation of Phenol by Using Reticulated Vitreous Carbon Immobilized Horseradish Peroxidase (Horseradish Peroxidase가 고정화된 다공성 탄소 전극을 이용한 페놀의 전기화학적 분해)

  • Cho, Seung-Hee;Yeon, Kyeong-Ho;Kim, Gha-Young;Shim, Joon-Mok;Moon, Seung-Hyeon
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.12
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    • pp.1263-1269
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    • 2005
  • Horseradish peroxidase, had the phenol degradation rate of 95% in aqueous phase, was covalently immobilized on the surface of reticulated vitreous carbon(RVC) and the degradation of phenol was performed with in situ generated $H_2O_2$-immobilized HRP complex in an electrochemical reactor. The incorporation of carboxylic group on the RVC surface was confirmed by FT/IR spectrometry and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC) was used for peptide bonds between the carboxylic groups on the RVC surface and amine groups from HRP. The optimal conditions of in situ $H_2O_2$ generation such as concentration($10{\sim}200$ mM) and pH($5.0{\sim}8.0$) of electrolyte, supply of $O_2(10{\sim}50$ mL/min) and applied voltage($-0.2{\sim}-0.8$ volt, vs. Ag/AgCl) from potentiostat/galvanostat were determined by concentration of hydrogen peroxide and current efficiency. It was observed that the RVC immobilized HRP was stable maintaining 89% of the initial activity during 4 weeks. The phenol degradation rate of 86% was attained under the optimal condition of in situ $H_2O_2$ generation.

Deep-learning based In-situ Monitoring and Prediction System for the Organic Light Emitting Diode

  • Park, Il-Hoo;Cho, Hyeran;Kim, Gyu-Tae
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.4
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    • pp.126-129
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    • 2020
  • We introduce a lifetime assessment technique using deep learning algorithm with complex electrical parameters such as resistivity, permittivity, impedance parameters as integrated indicators for predicting the degradation of the organic molecules. The evaluation system consists of fully automated in-situ measurement system and multiple layer perceptron learning system with five hidden layers and 1011 perceptra in each layer. Prediction accuracies are calculated and compared depending on the physical feature, learning hyperparameters. 62.5% of full time-series data are used for training and its prediction accuracy is estimated as r-square value of 0.99. Remaining 37.5% of the data are used for testing with prediction accuracy of 0.95. With k-fold cross-validation, the stability to the instantaneous changes in the measured data is also improved.

Preparation and Characterization of Polyimide/Carbon Nanotube Composites by in-situ Polymerization (In-situ 중합법에 의한 Polyimide/Carbon Nanotube 복합재료의 제조 및 특성)

  • Seo, Min-Kang;Park, Soo-Jin
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.223-224
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    • 2003
  • Polyimides (PI) are widely used in applications ranging from microelectronics to aerospace. Due to their insulating nature, significant accumulation of electrostatic charge may result on their surface, causing local heating and premature degradation to electronic components or space structures. Over the past decade, several publications have been made in fabrication and charaterization of CNT nanocomposites [1,2]. (omitted)

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Effect of Additives and Fermentation Periods on Chemical Composition and In situ Digestion Kinetics of Mott Grass (Pennisetum purpureum) Silage

  • Nisa, Mahr-un;Touqir, N.A.;Sarwar, M.;Khan, M. Ajmal;Akhtar, Mumtaz
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.6
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    • pp.812-815
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    • 2005
  • This study was conducted to see the influence of additives and fermentation periods on Mott grass silage (MGS) characteristics, its chemical composition and to compare the digestion kinetics of Mott grass (MG) and MGS in Nili buffaloes. Mott grass chopped with a locally manufactured chopper was ensiled using two additives, cane molasses and crushed corn grains each at 2, 4 and 6% of forage DM for 30 and 40 days in laboratory silos. The pH, lactic acid concentration, dry matter (DM), crude protein and fiber fractions of MGS were not affected by the type or level of additive and fermentation periods. The non-significant pH lactic acid concentration, and chemical composition of MGS indicated that the both molasses and crushed corn were utilized at similar rate for the growth of lactic acid bacteria and production of organic acids. The MG ensiled with molasses at 2% of fodder DM for 30 days was screened out for in situ digestion kinetics in Nili buffaloes. Ruminal DM and neutral detergent fiber (NDF) degradabilities of MGS were significantly (p<0.05) higher than that of MG. The DM and NDF rate of degradation, lag time and extent of degradation was nonsignificant between MGS and MG. The higher ruminal degradation of DM and NDF of MGS than MG was probably a reflection of fermentation of MG during ensilation that improved its degradability by improving the availability of easily degradable structural polysaccharides to ruminal microbial population. The results in the present study have indicated that MG ensiled with either 2% molasses or 2% crushed corn for 30 days has better nutritive value for buffalo.

SVE 및 미생물제제를 이용한 유류 오염토양의 현장 복원

  • 박영준;염규진;김선미;이문현;박광진;이영신
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.103-106
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    • 2003
  • This study was conducted to evaluate in-situ bioremediation ability of Bioil-D, microbial material for oil degradation, at a gas station that had been treated by SVE system. TPH concentrations and total contaminated soil volume were rapidly decreased after Bioil-D treatment. The performance of Bioil-D was also estimated based on the observation of microbial population at the soil samples and $CO_2$ concentration produced at the extraction wells. The field study showed a successful work of Bioil-D.

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미생물제제를 이용한 유류오염지역의 토양정화

  • 심두섭;송현주;박수진;고성환
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.360-363
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    • 2003
  • Bioremediation is often used for in situ remediation of petroleum-contaminated site. We studied the microbial degradation of hydrocarbon in an artificially diesel contaminated soil in laboratory microcosm. In control soil, about 30% of the initial TPH was diminished and the degradation of diesel oil was significantly enhanced by the addition of bioremediation agent (70% of TPH reduction).

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A Study on Persulfate Oxidation to Remove Chlorinated Solvents (TCE/PCE) (과황산(persulfate) 산화반응을 이용한 염소계 화합물(TCE, PCE) 분해에 관한 연구)

  • Song, Kyoung-Ho;Do, Si-Hyun;Lee, Hong-Kyun;Jo, Young-Hoon;Kong, Sung-Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.7
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    • pp.549-556
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    • 2009
  • In situ chemical oxidations (ISCO) are technologies for destruction of many contaminants in soil and groundwater, and persulfate has been recently studied as an alternative ISCO oxidant. Trichloroethylene (TCE) and tetrachloroethylene (PCE) were chosen for target organic compounds. The objective of this study is to demonstrate the influence of initial pH (3, 6, 9, 12), oxidant concentrations (0.01, 0.05, 0.1, 0.3, 0.5 M), and contaminants concentrations (10, 30, 50, 70, 100 mg/L) on TCE/PCE degradation by persulfate oxidation. The maximum TCE/PCE degradation occurred at pH 3, and the removal efficiencies with this pH condition were 93.2 and 89.3%, respectively. The minimum TCE/PCE degradation occurred at pH 12, and the removal efficiencies were 55.0 and 31.2%, respectively. This indicated that degradation of TCE/PCE decreased with increasing the initial pH of solution. Degradation of TCE/PCE increased with increasing the concentration of persulfate and with decreasing the concentration of contaminants (TCE/PCE). The optimum conditions for TCE/PCE degradation were pH 3, 0.5 M of persulfate solution, and 10 mg/L of contaminant concentration. At these conditions, the first-order rate constants ($k_{obs}$) for TCE and PCE were 1.04 and 1.31 $h^{-1}$, respectively.

In-situ Raman Spectroscopic Study of Nickel-base Alloys in Nuclear Power Plants and Its Implications to SCC

  • Kim, Ji Hyun;Bahn, Chi Bum;Hwang, Il Soon
    • Corrosion Science and Technology
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    • v.3 no.5
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    • pp.198-208
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    • 2004
  • Although there has been no general agreement on the mechanism of primary water stress corrosion cracking (PWSCC) as one of major degradation modes of Ni-base alloys in pressurized water reactors (PWR's), common postulation derived from previous studies is that the damage to the alloy substrate can be related to mass transport characteristics and/or repair properties of overlaid oxide film. Recently, it was shown that the oxide film structure and PWSCC initiation time as well as crack growth rate were systematically varied as a function of dissolved hydrogen concentration in high temperature water, supporting the postulation. In order to understand how the oxide film composition can vary with water chemistry, this study was conducted to characterize oxide films on Alloy 600 by an in-situ Raman spectroscopy. Based on both experimental and thermodynamic prediction results, Ni/NiO thermodynamic equilibrium condition was defined as a function of electrochemical potential and temperature. The results agree well with Attanasio et al.'s data by contact electrical resistance measurements. The anomalously high PWSCC growth rate consistently observed in the vicinity of Ni/NiO equilibrium is then attributed to weak thermodynamic stability of NiO. Redox-induced phase transition between Ni metal and NiO may undermine the integrity of NiO and enhance presumably the percolation of oxidizing environment through the oxide film, especially along grain boundaries. The redox-induced grain boundary oxide degradation mechanism has been postulated and will be tested by using the in-situ Raman facility.