• Title/Summary/Keyword: $I_c$ degradation

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A Study on Microbial Degradation for Removal of Toluene Vapour by Biofilter (Bio 필터를 이용한 Toluene 제거에서 미생물분해에 관한 연구)

  • 하상안;강신묵
    • Journal of environmental and Sanitary engineering
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    • v.14 no.1
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    • pp.24-30
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    • 1999
  • A biological filter for treatment of toluene among volatile organic compounds was studied. The investigation was conducted using specially built stainless steel columns packed with granular activated carbon and cold for removal of toluene. The G.A. and mold as filter material was also coated with Pseudomonas putida microorganisms.The biofilter unit was operated in the condition of moisture content vairation at gas loading rate of 12.5 l/min. Gaseous toluene taken from tedlar bag was analyzed by the use of G.C equipped with F.I.d detector. The removal efficiency of gaseous toluene was 95% at average inlet concentration of 950 ppm during bio-degradation operating condition. Effective removal efficiency was obtained with moisture content 27.5% at activated carbon and 32% at mold in this study. The effective operating condition were obtained with pH 6-8, temperature 28-42℃ for microbial degradation at gas loading rate of 12.5 l/min in packed material.

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Degradation of the Herbicide, Alachlor, by Soil Microorganisms -Part I. Degradation in the flooded paddy soils- (제초제 Alachlor의 토양미생물에 의한 분해 -제일보(第一報). 담수답토양에서의 분해-)

  • Lee, Jae-Koo
    • Applied Biological Chemistry
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    • v.27 no.2
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    • pp.64-72
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    • 1984
  • Alachlor, 2-chloro-2, '6'-diethyl-N-(methoxymethyl) acetanilide, which had been incubated in the flooded paddy soils yielded 1-formyl-2,3-dihydro-7-ethylindole, 2,6-diethylaniline, 2,6-diethylacetanilide, 2,6-diethyl-N-(methoxymethyl) acetanilide, 2-hydroxy-2, '6'-diethyl-N-(methoxymethyl) acetanilide, and three unidentifiable compounds as its degradation products. The water-soluble products of Alachlor in soil suspensions increased with incubation periods and similar results were obtained from the incubation of Rhizoctonia solani, as verified by use of the ring $-^{14}C-$labeled Alachlor. Streptomyces lavendulae Ru 3340-8 produced 2-hydroxy-2, '6'-diethyl-N-(methoxymethyl) acetanilide as the major degradation product as much as 25%, whereas Bacillus brevis IFO 3331, Bacillus cruciviae, and Pseudomonas putida did not produce it.

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Degradation Properties and Production of Fuels of Cellulose - Pyrolysis-Liquefaction - (셀룰로오스의 분해특성 및 연료물질 생성 (I) -열분해·액화반응-)

  • Lee, Jong-Jip;Lee, Byeong-Hak
    • Transactions of the Korean hydrogen and new energy society
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    • v.15 no.4
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    • pp.333-340
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    • 2004
  • In this study, thermochemical degradation by pyrolysis-liquefaction of cellulose, the effects of reaction time, reaction temperature, conversion yield, degradation properties and degradation products were investigated . Experiments were performed in a tube reactor by varying reaction time from 20 to 80 min at $200{\sim}500^\circ{C}$. Combustion heating value of liquid products from thermochemical conversion processes of cellulose was in the range of 6,920~6,960cal/g. After 40min of reaction at $400^\circ{C}$ in pyrolysis-liquefaction of cellulose, the energy yield and mass yield was as high as 54.3% and 34.0g oil/100g raw material, respectively. The liquid products from pyrolysis-liquefaction of cellulose contained various kinds of ketones, phenols and furans. ketones and furans could be used as high-octane-value fuels and fuel additives. However, phenols are not valuable as fuels.

Electro-mechanical properties in Bi-2223 superconducting composite tape due to axial fatigue loading (축방향 피로하중에 의한 Bi-2223 복합 초전도선재의 전기-기계적 특성)

  • Shin, Hyung-Seop;Dizon, John Ryan C.;Kim, Ki-Hyun;Oh, Sang-Soo;Ha, Dong-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.345-348
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    • 2004
  • For practical applications, the evaluation of reliability or endurance of HTS conductors is necessary. The mechanical properties and the critical current, $I_c$, of multifilamentary Bi-2223 superconducting tapes, externally reinforced with stainless steel foils, subjected to high cycle fatigue loading in the longitudinal direction were investigated at 77K. The S-N curves were obtained and its transport property was evaluated with the increase of repeated cycles at different stress amplitudes. The effect of the stress ratio, R, on the $I_c$ degradation behavior under fatigue loading was also examined considering the practical application situation of HTS tapes. Microstructure observation was conducted in order to understand the L degradation mechanism in fatigued Bi-2223 tapes.

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Preformulation Study of Aloesin in Buffered Aqueous Solutions (완충 수용액 중 Aloesin의 전처방화 연구)

  • 이윤진;곽혜선;전인구
    • YAKHAK HOEJI
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    • v.46 no.3
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    • pp.168-173
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    • 2002
  • The physicochemical properties of aloesin, which has been recently found to reduce renal toxicity induced by cis-platin, were studied including solubility, partition coefficient ( $P_{c}$ ), osmolality, and stability. The solubility of aloesin was about 500 mg/mι, and the $P_{c}$ value for n-octanol/water was 1.01 $\pm$ 0.03. The degradation of aloesin followed the pseudo-first-order kinetics and was dependent on temperature, pH and ionic strength. From the pH-rate profile, the optimal pH was found to be 2.0~3.0. Some metal ions increased the degradation rate in the rank order of M $n^{2+}$ > F $e^{3+}$ > C $u^{2+}$ > F $e^{2+}$. On the other hand, other metal ions such as B $i^{3+}$, $Ba^{2+}$, Z $n^{2+}$, N $i^{2+}$, $Co^{2+}$ and $Mg^{2+}$ did not show the unfavorable effects. After autoclaving, aloesin contents remaining were 81.8~98.8% of initial concentrations depending on pH. The most stable pH was 3.98 in the autoclaving. Osmolality increased linearly as concentration increased.sed.creased.sed.

Application of Gel-based Proteome Analysis Techniques to Studying Post-mortem Proteolysis in Meat

  • Hwang, I.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.9
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    • pp.1296-1302
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    • 2004
  • This study was conducted to evaluate the possible application of 2 D-SDS-PAGE (2 DE)-based proteome analysis techniques to the assessment of extreme proteolysis in postmortem skeletal muscle. Eight Hanwoo longissimus muscles were incubated immediately after slaughter for 24 h at 5$^{\circ}C$, 15$^{\circ}C$ or 36$^{\circ}C$. Warner Bratzler (WB)-shear force and ultrastructural configuration were determined at 24 h, and rate of proteolysis to 24 h was determined by 1 D-SDS-PAGE (1 DE) and 2 DE. In addition, tentative protein identification was performed from peptide mass fingerprints of MALDI-ToF analysis of major protein groups on 2 DE profiles. The result showed that although ultrastructural configuration was similar between the 5$^{\circ}C$ and 36$^{\circ}C$ treatments, meat at 5$^{\circ}C$ had higher WBshear force (approximately 5 kg greater). A higher rate of protein degradation at 36$^{\circ}C$ was observed based on Troponin-T degradation, 1 DE, and 2 DE analysis. This indicates that proteolysis during the early postmortem period was a significant determinant of shear force at 24 h. Little difference in proteolysis between 5$^{\circ}C$ and 15$^{\circ}C$ treatments was found based on classic 1 DE profile assessment. Meanwhile, considerable differences in the 2 DE profiles between the two treatments were revealed, with substantially higher rate of proteolysis at 15$^{\circ}C$ compared to 5$^{\circ}C$. Nuclease treatment improved 2 DE profile resolution. 400 ${\mu}$g and 600 ${\mu}$g of sample loading appeared to be appropriate for 24 cm pH 3-10 and pH 5-7 IPG strips, respectively. Protein detection and quantification of the 5$^{\circ}C$, 15$^{\circ}C$ and 36$^{\circ}C$ 2 DE profiles revealed 78, 163 and 232 protein spots respectively that were differentially modified in terms of their electrophoretic properties between approximately pI 5.3-7.7 with the molecular weight range of approximately 71-12 kDa. The current results demonstrated that 2 DE was a superior tool to 1 DE for characterising proteolysis in postmortem skeletal muscle.

Performance Evaluation of Disk I/O for Web Proxy Servers (웹 프락시 서버의 디스크 I/O 성능 평가)

  • Shim Jong-Ik
    • The KIPS Transactions:PartC
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    • v.12C no.4 s.100
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    • pp.603-608
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    • 2005
  • Disk I/O is a major performance bottleneck of web proxy server. Today's most web proxy sowers are design to run on top of a general purpose file system. But general purpose file system can not efficiently handle web cache workload, small files, leading to the performance degradation of entire web proxy servers. In this paper we evaluate the performance potential of raw disk to reduce disk I/O overhead of web proxy servers. To show the performance potential of raw disk, we design a storage management system called Block-structured Storage Management System (BSMS). And we also actually implement web proxy server that incorporate BSMS in Squid. Comprehensive experimental evaluations show that raw disk can be a good solution to improve disk I/O performance significantly for web proxy servers.

Differential Expression and Stability of Endogenous Nuclear Factor E2-related Factor 2 (Nrf2) by Natural Chemopreventive Compounds in HepG2 Human Hepatoma Cells

  • Jeong, Woo-Sik;Keum, Young-Sam;Chen, Chi;Jain, Mohit R.;Shen, Guoxiang;Kim, Jung-Hwan;Li, Wenge;Kong, Ah-Ng Tony
    • BMB Reports
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    • v.38 no.2
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    • pp.167-176
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    • 2005
  • Nuclear factor-E2-related factor 2 (Nrf2) is known as a key regulator of ARE-mediated gene expression and the induction of Phase II detoxifying enzymes and antioxidant enzymes, which is also a common property of many chemopreventive agents. In the present study, we investigated the regulatory role of different chemopreventive agents including sulforaphane (SUL), allyl isothiocyanate (AITC), indole-3-carbinol (I3C), and parthenolide (PTL), in the expression and degradation of Nrf2 and the induction of the antioxidant enzyme HO-1. SUL strongly induced Nrf2 protein expression and ARE-mediated transcription activation, retarded degradation of Nrf2 through inhibiting Keap1, and thereby activating the transcriptional expression of HO-1. AITC was also a potent inducer of Nrf2 protein expression, ARE-reporter gene and HO-1 but had little effect on delaying the degradation of Nrf2 protein. Although PTL and I3C could induce ARE reporter gene expression and Nrf2 to some extent, they were not as potent as SUL and AITC. However, PTL dramatically induced the HO-1 expression, which was comparable to SUL, while I3C had no effect. In addition, when treated with SUL and PTL, inhibition of proteasome by MG132 did not cause additional accumulation of Nrf2, suggesting the involvement of other degradation mechanism(s) in the presence of these compounds such as SUL and PTL. In summary, the results of our current study indicated that different chemopreventive compounds have different regulatory properties on the accumulation and degradation of Nrf2 as well as the induction of cellular antioxidant enzyme HO-1.

The Effects of Copolymer Additives for Drag Reduction on Turbulent Flow (합성고분자첨가제의 난류마찰저항 감소효과 연구)

  • Kim, N.S.;Kim, C.B.;Kim, I.S.;Choi, H.J.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.5 no.3
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    • pp.207-216
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    • 1993
  • Experimental investigations have been carried out to find the effect of drag reduction caused by effective polymer additives in turbulent flows. The experiments were undertaken with a test section of 9.8mm pipe diameter and 3500 mm pipe length(L/D=357) in a closed loop, and Copolymer-X and Polyacrylamide(PAAM) were used as polymer additives for comparisons. The tests were carried out under different polymer concentrations, and the temperatures of the flow considered were $26^{\circ}C$, $60^{\circ}C$ at the flow velocity of 5.3 m/s. The rate of drag reduction obtained by Copolymer-X is found to be considerably higher than that of PAAM in turbulent flows. Copolymer-X is also found to be very reliable for mechanical degradation, which has not been the case in any other additives. It is concluded that Copolymer-X is considered to be one of the most effective agents as an additive especially for long time hydraulic transports. It is also found that polymer degradation in more likely at lower polymer concentrations in the turbulent flows.

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Determination of Optimal Conditions of Pressure Toasting on Legume Seeds for Dairy Deed Industry : I. Effects of Pressure Toasting on Nutritive Values of Lupinus albus in Lactating Dairy Cows

  • Yu, P.;Goelema, J.O.;Tamminga, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.8
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    • pp.1205-1214
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    • 1999
  • Whole lupinus albus seeds were pressure toasted at temperatures of 100, 118 and $136^{\circ}C$ for 3, 7, 15 and 30 min to study rumen degradation and post-rumen digestion and to determine optimal heating conditions for the Dutch dairy feed industry. In sacco nylon bag and mobile bag techniques were employed for rumen and intestine incubations to determine ruminal degradation characteristics and intestinal digestion of crude protein (CP) in 4 lactation rumen cannulated and 4 lactating intestinal cannulated Dutch dairy cows fed 47% hay and 53% concentrate according to Dutch dairy requirements. Measured rumen degradation characteristics were soluble fraction (S), undegradable fraction (U), potentially degradable fraction (D), lag time (T0) and rate of degradation (Kd) of insoluble but degradable fraction. Percentage bypass feed protein (BCP), ruminal microbial protein synthesized based on available nitrogen (N_MP) and that based on available energy (E_MP), true protein supplied to the small intestine (TPSI), truly absorbed BCP (ABCP), absorbed microbial protein (AVP) in the small intestine, endogenous protein losses in the digestion (ENDP), true digested protein in the small intestine (TAP or DVE in Dutch) and degraded protein balance (PDB or OEB in Dutch) were totally evaluated using the new Dutch DVE/OEB System. Pressure toasting decreased (p<0.001) rumen degradability of CP. It reduced S (p<0.05) and Kd (p=0.06), increased D (p<0.05) and U (p<0.01) but did not alter T0 (p>0.05), thus resulting in dramatically increased BCP (p<0.001) with increasing time and temperature from 73.7 (raw) up to 182.5 g/kg DM ($136^{\circ}C/15min$). Although rumen microbial protein synthesized based on available energy (E_MP) was reduced, true protein (microbial and bypass feed protein) supplied to the small intestine (TPSI) was increased (p<0.001) from 153.1 (raw) to 247.6 g/kg DM ($136^{\circ}C/15min$). Due to digestibility of BCP in the intestine not changing (p>0.05) average 87.8%, the absorbed BCP increased (p<0.001) from 62.3 (raw) to 153.7 g/kg DM ($136^{\circ}C/15min$). Therefore DVE value of true digested protein in the small intestine was significantly increased (p<0.001) from 118.9 (raw) to 197.0 g/kg DM ($136^{\circ}C/15min$) and OEB value of degraded protein balance was significantly reduced (p<0.001) from 147.2 (raw) to 63.1 g/kg DM ($136^{\circ}C/15min$). It was concluded that pressure toasting was effective in shifting degradation of CP of lupinus albus from the rumen to small intestine without changing intestinal digestion. Further studies are required on the degradation and digestion of individual amino acids and on the damaging effects of processing on amino acids, especially the first limiting amino acids.