• Title/Summary/Keyword: electrophoretic

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Fabrication of SiCf/SiC Composites using an Electrophoretic Deposition

  • Lee, Jong-Hyun;Gil, Gun-Young;Yoon, Dang-Hyok
    • Journal of the Korean Ceramic Society
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    • v.46 no.5
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    • pp.447-451
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    • 2009
  • Continuous SiC fiber-reinforced SiC composites ($SiC_f$/SiC) were fabricated by electrophoretic deposition (EPD). Nine types of slurries with different powder contents, binder resin amounts and slurry pH were deposited on Tyranno$^{TM}$-SA fabrics by EPD at 135 V for ten minutes to determine the optimal conditions. Further EPD using the optimum slurry conditions was performed on fabrics with four different pyrolitic carbon (PyC) thicknesses. The density of the hot-pressed composites decreased with increasing PyC thickness due to the difficulty of infiltrating the slurry into the narrow gaps between the fibers. On the other hand, the mechanical strength increased with increasing PyC thickness despite the decrease in density, which was explained by the enhanced crack deflection with increasing PyC thickness. The $SiC_f$/SiC composites showed the highest density and flexural strength of 94% and 342 MPa, respectively, showing EPD as a feasible method for dense $SiC_f$/SiC fabrication.

Field emission properties of carbon nanotubes grown on micro-tip substrates using an electrophoretic deposition method (미세 팁 기판 위에 전기영동법으로 성장시킨 탄소 나노튜브의 전계방출 특성)

  • Chang, Han-Beet;Noh, Young-Rok;Kim, Jong-Pil;Park, Jin-Seok
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.4
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    • pp.7-12
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    • 2010
  • Field-emission characteristics of carbon nanotubes(CNTs), which were grown on conical-type tungsten micro-tips by using an electrophoretic deposition(EPD) method, were examined. The EPD method proved to be convenient to manipulate and arrange CNTs from well dispersed suspensions onto such tip-type substrates. The growth rate of CNTs was proportional to the applied d.c. bias voltage and the process time. It was observed from the Raman study that the EPDproduced CNTs showed better crystal qualities with the Raman intensity ratio( $I_D$/$I_G$) of 0.41-0.42 than the CVD-produced CNTs and their crystal qualities could be further improved by thermal annealing. The electron emitters based on the EPDCNTs showed excellent field emission properties, such as the threshold voltage for electron emission of about 620 V and the maximum emission current of about 345 ${\mu}A$. In addition, the EPD-CNTs exhibited the stable long-term(up to 40 h) emission capability and the emission stability was enhanced by thermal annealing.

Two-dimensional Electrophoretic Analysis of Nucleotide phosphate Kinase Mediated Hydrogen Peroxide Cross-linking in Saccharamyces cerevisiae (2-D 전기영동 분석을 통한 $H_2O_2$와 연계된 효모 시스템 NDPK에 관한 연구)

  • Moon Hae-Jeong;Yun Dae-Jin;Park Chang-Ho
    • KSBB Journal
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    • v.21 no.1 s.96
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    • pp.16-19
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    • 2006
  • Oxidative modification of nucleoside diphosphate kinase (NDPK) is identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. The quaternary structure of NDPK appears to be regulated by cross-linking with an oxidant, $H_2O_2$. We compared roles of NDPK in each of wild type and ynk mutant against oxidative stress. Six specific proteins changed by $H_2O_2$ were identified using two-dimensional electrophoretic analysis. YNK regulated several proteins, related to $H_2O_2$ signaling functions. These results suggest that one of the important functions of NDPK is the regulation of cellular redox state.

Effects of Surface Pretreatment on Deposition and Adhesion of Electrophoretic Paint on AZ31 Mg Alloy

  • Nguyen, Van Phuonga;Moon, Sungmo
    • Journal of the Korean institute of surface engineering
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    • v.50 no.2
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    • pp.72-84
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    • 2017
  • In this work, electrophoretic paint (E-paint) was deposited on AZ31 Mg alloy after four different surface pretreatments: knife abrading, SiC paper abrading, deionized (DI) water immersion and NaOH immersion. The deposition process of E-paint was studied by analyses of voltage-time and current-time curves, amount of deposited paint, current efficiency and surface oxide film resistance and the adhesion of E-paint was examined by tape test before and after immersion in DI water for 500 h at $40$^{\circ}C$. It was found that the induction time for the deposition, the amount of deposited paint and the current efficiency are inversely proportional to the resistances of surface films prepared by different surface pretreatment methods. The electrophoretic painting showed longer inductance time, larger amount of deposited paint and higher current efficiency on the highly conducting surfaces, such as knife-abraded and SiC-abraded surfaces than on the less conducting surfaces, such as DI water-immersed and NaOH-immersed samples. Excellent adhesion was observed on the E-paintings deposited onto knife-abraded and SiC-abraded AZ31 Mg alloy samplesSiC-abraded AZ31 Mg alloy samples.

Separation of Barley Seed Proteins by Disc Electrophoresis (Disc electrophoresis에 의한 대맥종자단백질의 분리)

  • 최종열
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.10
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    • pp.91-97
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    • 1971
  • Fifteen samples of barley seed proteins representing winter 6-rowed, spring 6-rowed and spring 2-rowed group were separated by disc electrophoresis. Photographic, densitometric and diagrammatic representation were presented to make comparison possible. Eighteen to twenty one bands were detected in each gel. Electrophoretic spectrum of each variety was highly variety specific showing that the spectrum is the reflection of hereditary constituents of a organism. Related variety showed identical or nearly identical pectrum. All winter 6-rowed barley showed very faint B2 band, while spring 6-rowed and spring 2-rowed barley showed dense or less dense B2 band. All spring barley showed B3 band, while all winter barley showed B4 band.

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Deposition of aluminum nitride nanopowders and fabrication of superhydrophobic surfaces (질화알루미늄 나노분말의 부착과 이를 활용한 초소수성 표면 제작)

  • Kwangseok Lee;Heon-Ju Choi;Handong Cho
    • Journal of the Korean institute of surface engineering
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    • v.57 no.1
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    • pp.49-56
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    • 2024
  • Superhydrophobic surfaces have been expected to be able to provide considerable performance improvements and introduce innovative functions across diverse industries. However, representative methods for fabricating superhydrophobic surfaces include etching the substrate or attaching nanosized particles, but they have been limited by problems such as applicability to only a few materials or low adhesion between particles and substrates, resulting in a short lifetime of superhydrophobic properties. In this work, we report a novel coating technique that can achieve superhydrophobicity by electrophoretic deposition of aluminum nitride (AlN) nanopowders and their self-bonding to form a surface structure without the use of binder resins through a hydrolysis reaction. Furthermore, by using a water-soluble adhesive as a temporary shield for the electrophoretic deposited AlN powders, hierarchical aluminum hydroxide structures can be strongly adhered to a variety of electrically conductive substrates. This binder-free technique for creating hierarchical structures that exhibit strong adhesion to a variety of substrates significantly expands the practical applicability of superhydrophobic surfaces.

Electrophoretic Karyotypes of Fusarium oxysporum f. sp. lycopersici (Fusarium oxysporum f. sp. lycopersici의 Electrophoretic Karyotype)

  • Kim, Young-Tae;Kim, Hong-Gi
    • The Korean Journal of Mycology
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    • v.27 no.2 s.89
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    • pp.112-118
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    • 1999
  • Strains of Fusarium oxysporum f. sp. lycopersici isolated from Korea, Japan and U.S.A. were used for electrophoretic karyotype (EK) analysis. Chromosome separations on FastLane agarose gels (FMC BioProducts, Rockland, ME), called pulsed field gel electrophoresis (PFGE), were performed by CHEF-DRII apparatus (Bio-Rad Laboratories, Melville, NY) using TAE as a running buffer. To obtain optimal condition for separation of chromosome sized DNAs, variable running conditions such as field strengths, swithching intervals, and running time were applied in CHEF gel electrophoresis. We were able to resolve 9 to 11 chromosome sized DNAs ranging in size from 0.76 to 6.41 Mb in isolates from Korea and estimate that the total genome size was ranging from 35.29 to 38.92 Mb. Distinct differences in length range and genome size exist among isolates from different countries. Isolates from Japan and U.S.A. were resolved 9 to 11 chromosome sized DNAs ranging in size from 1.24 to 6.85 Mb and estimated that the total genome size was ranging from 35.32 to 43.87 Mb. Isolates from variable provinces in Korea had the same or similar chromosomal polymorphism and showed different chromosomal DNA patterns compared to isolates from the other countries.

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Studies on the Varietal Differences of the Electrophoretic Protein Patterns in the Pupal Haemolymph of the Silkworm, Bombyx mori (가잠용에 있어서 체액단백질의 품종간 차이에 대하여)

  • Lee, Sang-Mong;Park, Gwang-Ui;Mun, Jae-Yu
    • Journal of Sericultural and Entomological Science
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    • v.26 no.1
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    • pp.35-51
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    • 1984
  • In order to know the similarity of the electrophoretic protein patterns, distributional aspects of the frequency in each protein band, differences of protein patterns between female and male, and the number of the total protein bands of each variety in the haemolymph of the silkworm pupae according to their geographical origin, the silkworm varieties, and both the sexes, variable electrophoretic protein patterns were observed by polyacrylamide gel electrophoresis, using the silkworm strains which have been reared in the sericultural experiment station. 1. The total number of electrophoretic protein bands classified were twenty-eight, and nearly fourteen bands were shown by each variety on an average. 2. According to their geographical origin, the mean values of the similarity were 20.0%, 28.3% and 14.3% in Japanese, Chinese and European respectively, and the highest similarity was observed between Chinese varieties. 3. The similarity of 129 varieties were tested and it was 22.5%, 23.5% in female and male respectively. 4. The electrophoretic protein patterns in 129 varieties were tested and variation was found in 109 patterns in female and 112 in male. 5. The frequency of the each specified protein band in female and male having variation in protein bands in each variety was found averagely 6.6%. 6. The distribution frequency of the classified 28 protein bands in both the sexes within each geographical origin was variable from 0% to 100%. 7. Among the classified 28 protein bands, HP 11 protein band was found common in all the varieties tested. 8. HP 3 and HP 4 protein bands in female showed high density in electropherograms than in male.

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Electrophoretic Patterns of Myofibrillar Proteins by Sugar Addition and Heat Treatment (당첨가 및 가열처리에 의한 근원섬유 단백질의 전기영동 Pattern 변화)

  • Yang, Jong-Beom;Yoon, Won-Ho;Ko, Myung-Soo;Kim, Chang-Han
    • Korean Journal of Food Science and Technology
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    • v.22 no.6
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    • pp.640-645
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    • 1990
  • Changes of the electrophoretic patterns of myofibrillar proteins by sugar audition and heat treatment was studied. In the electrophoretic patterns of myofibrills prepared from no sugar added meat, as the intensity of higher molecular weight band such as myosin heavy chain showed a remarkable decrease by heating, that of lower molecular weight band such as actin showed no change. That from sugar added meat showed more remarkable decrease in the intensity of higher molecular weight band than that from no sugar added meat and this tendency was most noticeable in case of glucose addition. The effect of digestion with proteases after sugar addition and heat treatment on the electrophoretic patterns exhibited the descending order of trypsin >chymotrypsin >peptidase. By digestion with these three enzymes at one time myosin produced 27.000 dalton and 32.000 dalton components, and actin showed 16,000 dalton component. in the case of heat treatment, a part of actin was not digested. And in the case of glucose addition the myosin aggregates was not digested with these three enzymes at a time.

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