• Title/Summary/Keyword: Alkaline treatment

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The effect of step heat treatment in the critical current density of BSCCO 2223 tapes (BSCCO 2223선재의 임계전류밀도에 영향을 미치는 단계별 열처리의 효과)

  • 박성창;유재무;고재웅;김영국;김철진
    • Progress in Superconductivity
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    • v.4 no.1
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    • pp.90-93
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    • 2002
  • The sintering process of BSCCO 2223 tapes is a complex process that is very sensitive to parameters, such as temperature, oxygen partial pressure, heating and cooling rate and holding time. During the first heat treatment, 2212 phase of precursor powder is partially transformed into 2223 phase and some residual secondary phases, such as $(Bi,Pb)_2$$Sr_2$CuO/sub y/(2201), $(Ca,Sr)_2$CuO/sub y/(2/1AEC), (Ca,Sr)/sub 14/Cu/sub 24/O/sub 41/(14/24 AEC) etc. The secondary phases are difficult to be removed from the BSCCO 2223 matrix on the heat treatment. These secondary phases degrade the critical current density. In order to minimize the amount and size of alkaline earth cuprate(AEC) particles step heat treatment is applied during the first heat treatment under the varying atmosphere. Experimental results showed that by adapting the step heat treatment process, the amount and particle size of the secondary phases in the final tapes are decreased. Consequently, the BSCCO 2223grain texture and Jc properties are improved.

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Tissue level of chloramphenicol and haematological changes in olive flounder, Paralichthys olivaceus orally administered chloramphenicol (Chloramphenicol의 경구투여에 따른 양식 넙치, Paralichthys olivaceus의조직내 잔류량 및 혈액학적 변화)

  • Jeong, So-Jeong;Seo, Jeong-Su;Eom, Hye-Gyeong;Kim, Na-Yeong;Lee, Sang-Hwan;Heo, Min-Do;Jeong, Hyeon-Do;Jeong, Jun-Gi
    • Journal of fish pathology
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    • v.17 no.2
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    • pp.113-121
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    • 2004
  • This study was performed to investigate the pathphysiological side effects of chloramphenicol (CAP) on olive flounder, Paralichthys olivaceus. 150 mg/kg/bw/day of CAP was orally administered forcedly to flounder for 4 days and then the flounder was monitored for 11 days. The level of hematocrit was significantly decreased from 2 day to 3 day of CAP treatment in CAP-treated group. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT) were slightly increased during the treatment of CAP and gradually decreased after the treatment of CAP. The levels of blood urea nitrogen (BUN) and creatinine kinase (CK), although not significant, were slightly increased during the treatment of CAP. The level of lactate dehydrogenase (LDH) was not changed during the treatment of CAP but slightly increased after the treatment of CAP. However, no histopathological changes were observed in various organ after the treatment. From these results, it is suggest that CAP can evoke several side effects on haematopoietic organs in olive flounder.

Enhancement of Field Emission Characteristics of CuO Nanowires Formed by Wet Chemical Process (습식공정으로 형성된 구리산화물 나노와이어의 전계방출특성 향상)

  • Sung Woo-Yong;Kim Wal-Jun;Lee Seung-Min;Lee Ho-Young;Park Kyung-Ho;Lee Soonil;Kim Yong-Hyup
    • Journal of the Korean institute of surface engineering
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    • v.37 no.6
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    • pp.313-318
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    • 2004
  • Vertically-aligned and uniformly-distributed CuO nanowires were formed on copper-coated Si substrates by wet chemical process, immersing them in a hot alkaline solution. The effects of hydrogen plasma treatment on the field emission characteristics of CuO nanowires were investigated. It was found that hydrogen plasma treatment enhanced the field emission properties of CuO nanowires by showing a decrease in turn-on voltage, and an increase in emission current density, and stability of current-voltage curves. However, the excessive hydrogen plasma treatment made the I-V curves unstable. It was confirmed by XPS (X-ray Photoelectron Spectroscopy) analysis that hydrogen plasma treatment deoxidized CuO nanowires, thereby the work function of the nanowires decreased from 4.35 eV (CuO) to 4.1 eV (Cu). It is thought that the decrease in the work function enhanced the field emission characteristics. It is well-known that the lower the work function, the better the field emission characteristics. The results suggest that the hydrogen plasma treatment is very effective in achieving enhanced field emission properties of the CuO nanowires, and there may exist an optimal hydrogen plasma treatment condition.

Modification of Wool Fiber by Enzymatic Treatment(II) -The Dyeing Behavior of Wool Fiber Enzyme-treated- (효소처리에 의한 양모섬유의 개질 (II) -효소처리 양모의 염색성 고찰 -)

  • 김태경;심창섭;조민정;임용진
    • Textile Coloration and Finishing
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    • v.5 no.3
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    • pp.206-215
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    • 1993
  • In the prior study, wool gabardines were treated with alkaline proteases which were some kinds of enzyme to decompose protein, and their tensile strengths were determined, and the surface of the fibers were also observed using a scanning electron microscope. Enzylon ASN 30 and Alkalase 2.5L DX did not show much effect on the weight loss of wool, however, the weight loss of wool increased considerably with treating Esperase 8.0L. Pretreatment of wool with dichloloisocyanuric acid before protease-treatment increased the weight loss of wool to a great extent. In this study, the enzyme treated wools dyeing behaviors with acid dye, Milling Cyanine 5R, were mainly investigated. The protease-treatment remarkably increased not only the rate of dyeing but also the saturation dye uptake. From these results, it seemed likely that the structural relaxation of adhesive filler of interscale or intercellular cement facilitated the dye penetration into the fibers, at the same time, the change in the inner structure of the wool fibers by the protease made the fixation of the dyes more efficient.

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An in Vivo Study of High Voltage Pulsed Current on pH in the Healing Wound Bed

  • Song, Byung-H.
    • Journal of Korean Physical Therapy Science
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    • v.6 no.4
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    • pp.173-178
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    • 1999
  • The purpose of this study was to determine the effect of High Voltage Pulsed Current on pH in the healing wound bed. Seven adults, four males and three females, were studied with a total of fifty-five viable treatment sessions. Using a Cardy Digital pH meter, we measured the pH in the wound bed following saline rinse both prior to treatment and after a forty-five minute treatment. Analysis of all viable records(n=54) did not show a significant change in pH(p=0.82). The mean pH change in NoN-Smokers(-0.14) was more acidic when compared to the mean pH change in smokers(0.27) which was more alkaline.

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Studies on the Coated Broke Recycling in the Papermaking(II)-Effect of Sulfuric acid Treatment on Coated Broke Recycling - (도공파지의 재생에 관한 연구(제 2보)-황산처리가 도공파지 재생공정에 미치는 영향)

  • 이용규;김창근
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.4
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    • pp.23-29
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    • 1999
  • The effect of dilute sulfuric acid treatment was examined to improve recyclability of coated brokes. Turbidity , electric conductivity , and cationic demand of the white water from coated broke prepared from an alkaline base paper was determined. Sulfuric acid treatment was found to be effective in dissolving undisintegrated substances such as binders, pigments, and fibers. The properties of papers prepared by adding the broke to pulp stock up to 30% dry weight were examined . With the increase of broke addition, retention, sizing degree and smoothness were improved ; on the other hand, formation uniformness, air permeability and internal bonding strength were decreased. The extent of improvement by broke addition was greater for the surfuric acid-treated broke than the control broke. It was concluded that the use of coated broke should be limited within 10-15% weight of the product for either type of broke.

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Nuclear DNA Damage and Repair in Normal Ovarian Cells Caused by Epothilone B

  • Rogalska, Aneta;Marczak, Agnieszka
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6535-6539
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    • 2015
  • This study was designed to assess, whether a new chemotherapeutic microtubule inhibitor, Epothilone B (EpoB, Patupilone), can induce DNA damage in normal ovarian cells (MM14.Ov), and to evaluate if such damage could be repaired. The changes were compared with the effect of paclitaxel (PTX) commonly employed in the clinic. The alkaline comet assay technique and TUNEL assay were used. The kinetics of DNA damage formation and the level of apoptotic cells were determined after treatment with IC50 concentrations of EpoB and PTX. It was observed that PTX generated significantly higher apoptotic and genotoxic changes than EpoB. The peak was observed after 48 h of treatment when the DNA damage had a maximal level. The DNA damage induced by both tested drugs was almost completely repaired. As EpoB in normal cells causes less damage to DNA it might be a promising anticancer drug with potential for the treatment of ovarian tumors.

A Study on the Tannin Treatment of Silk Fabrics(III) - Comparion Condensed Tannin with Hydrlyzable Tannin - (견의 탄닌처리에 관한 연구(III) - 축합형 탄닌과 가수분해형 탄닌의 비교 -)

  • 설정화;최석철;조경래
    • Textile Coloration and Finishing
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    • v.7 no.3
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    • pp.60-67
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    • 1995
  • This study was made to investigate the effect of silk fabrics treated with mimosa and tannic acid-weighting effect, surface color according to temprature, treatment time, concentration, pH. The results were as follows ; 1. The wavelength of maximum absorption of mimosa and tannic acid solution appeared at 278.5nm and 275.0nm, respectively. By the irradiation, spectra at wavelength of maximum absorption of mimosa solution disappeared, but those of tannic acid solution decreased after 48hr irradiation. 2. The tannin weighting increased with the increase of concentration, treatment temperature at 8$0^{\circ}C$, acidic condition. In case of tannic acid, it was higher than mimosa. 3. Surface color of silk fabric with mimosa changed from 2.8YR to 5.8YR acc-ording to the increase o( tannin concentration but in case of tannic acid itchanged from 4.2Y to 3.9Y. It was more changed acidic or alkaline conditionthan origine solution.

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Development of Auto-hydrolysis Method for Preparing Cotton Linter Regenerated Fibers of Textile Fabrics (방직용 재생펄프 제조를 위한 면 린터의 자기가수분해 공정 개발)

  • Sohn, Ha Neul;Park, Hee Jung;Seo, Yung Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.6
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    • pp.81-88
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    • 2015
  • The molecular weight (MW) and crystallinity of cotton linter need to be controlled to be dissolved well in N-methylmorpholine N-oxide (NMMO) solvent for manufacturing regenerated fibers of clothing fabrics. Electron beam irradiation or sulfuric acid pre-treatment followed by alkaline peroxide bleaching has been used to control MW effectively and to improve brightness of cotton linter. Auto-hydrolysis of cotton linter without electron beam irradiation or chemical pre-treatment was found to be effective as an alternative pre-treatment method. Removal of metal ions, that hampered dissolution of cotton linter by NMMO, was also investigated when the auto-hydrolysis was accompanied with ionic polymers and chelating agent.

Effects of sodium hydroxide cleaning on polyvinylidene fluoride fouled with humic water

  • Jang, Yoon-sung;Kweon, JiHyang;Kang, Min-goo;Park, Jungsu;Jung, Jae Hyun;Ryu, JunHee
    • Membrane and Water Treatment
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    • v.8 no.2
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    • pp.149-160
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    • 2017
  • This study investigated effects of NaOH cleaning on the intrinsic permeability of polyvinylidene fluoride (PVDF) membranes and flux recoveries and membrane resistances under various conditions encountered during ultrafiltration in water treatment plants. The NaOH cleaning using 10,000 mg/L NaOH led to discoloration of PVDF membranes and had little effect on water flux. The NaOH cleaning was efficient in removing the fouling layer caused by humic water. However, long filtration induced a fouling layer that was not removed easily by NaOH cleaning. The lower temperature during filtration yielded rapid increases in transmembrane pressure and decreases in NaOH cleaning efficiency. The alkaline cleaning of PVDF changed the membrane properties such as the hydrophobicity and morphology. Foulant properties, operational conditions such as temperature, and chemical agents should be considered for cleaning strategies for PVDF applied in water treatment.