• Title, Summary, Keyword: electrofusion

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Development of Intelligent Electrofusion Welding Machine with Real-time Recognition of Conductive Plastic Heater Characteristics (전도성 플라스틱 발열체의 실시간 특성인식이 가능한 지능형 플라스틱 이음관 융착기 개발)

  • Kim, Dae Young;Yi, Keon Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.8
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    • pp.1098-1103
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    • 2014
  • This study deals with the development of an electrofusion welding machine that is capable of joining plastic pipes using a recently developed electrofusion fitting. This fitting has built-in conductive plastics that are used to weld the joint together as a heating element. In order to explain the mechanism of the new machine, 1) the resistance characteristics of the heating element were explained, 2) the method of electric welding that uses the electrofusion fitting was described, and 3) the method of power supply based on controlling the firing angle was explained. A control system for an intelligent electrofusion welding machine was proposed. This system has the ability to recognize the diameter of an electrofusion fitting using a lookup-table based on the difference of resistance curves according to fitting types, and it is able to weld the fittings regardless of the ambient temperature. A new algorithm was developed to control the power of electric welding through the recognition of feature points from the resistance curve of the heating element. In order to evaluate the performance of the developed welding machine, tests involving the welding of 16 mm- and 20 mm-type fittings were carried out. Examining the welding results, we concluded that the proposed welding machine will offer high productivity and reliability in the field of electrofusion welding.

Studies on the Electrofusion between Lactobacillus acidiophilus 88 and Lactobacillus bulgaricus IFO 13953 (Lactobacillus acidophilus 88과 Lactobacillus bulgaricus IFO 13953간의 Electrofusion에 관한 연구)

  • 조영배;김혜정;김성구;백형석;전홍기
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.1
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    • pp.143-149
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    • 1996
  • 균주개량 방법의 일환으로 electrofusion 법을 이용하여 protease 화성, lipase 활성, 내열성, 내산성 등이 우수한 L. bulgaricus와 bacteriocin을 생산하는 L. acidophilus 간의 융합조건을 검토하였다. Electrofusion에 의해 생성된 융합주는 식별하기 위해 streptomycin(2mg/ml)과 lincomycin(5$\mu\textrm{g}$/ml)에 내성을 나타내는 L. bulgaricus 변이주이와 kanamucin (600$\mu\textrm{g}$/ml)에 내성을 나타내는 L. acidophilus 88 변이주를 분리하였다. Electrofusion을 500V/cm, 100mses(49phms, 2300 capacotance)에서 수행했을 때 가장 융합이 잘 일어났으며 전기장의 세시와 시간이 증가할수록 융합요율이 현저히 감소하였다. 2가 양이온은 대체적으로 융합효율을 감속시키는 경향을 나타내었으나 1mM MgCl$_2$에서 융합 효율이 약간 증가하였다. PEG 400을 elec-trogusion buffer에 30%되도록 첨가했을 때, 가장 양호한 융합효율을 나타내었으며 그 이상에서는 오히려 융합 효율이 감소하였다. Electrofusion법과 PEG 매개에 의한 융합법의 융합 효율을 비교한 결과, 거의 비슷한 융합 효율을 나타내었으나 electrofusion 법과 PEG매개에 의한 융합법을 혼합하였을 때 가장 양호한 융합 효율을 나타내었다.

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Study for Non-Destructive Testing of Polyethylene Electrofusion Joints - Ultrasonic Imaging test (폴리에틸렌 배관의 전기융착부 비파괴검사기술에 관한 연구)

  • Kil Seong Hee;Kwon Jeong Rock
    • Journal of the Korean Institute of Gas
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    • v.8 no.3
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    • pp.31-36
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    • 2004
  • Electrofusion(EF) joints have been widely used as they are easy to fuse and suitable for high-quality joints for polyethylene(PE) pipes. This paper studies the cause of defects and classifies 5 types of defects. The defect detection technique for electrofusion joints of polyethylene piping is utilized by the ultrasonic phased array technique to obtain ultrasonic images of electrofusion joints. Test sample joints have been designed and fabricated using artificial defects which were made using paper. Finally, we studied the condition of electrofusion in the field and analyzed the main causes of defects. And we classified the defect types as local lack of fusion, sand inclusion, voids or air inclusion, short stab, excess penetration or excess bead.

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Study for Field Inspection of Phase-Array Ultrasonic for Electro-fusion Joints of Polyethylene Gas Pipes (폴리에틸렌 가스배관 전기융착부 위상배열초음파검사 현장사례 연구)

  • Kil Seong-Hee;Kwon Jeong-Rock;Park Kyo-Shik
    • Journal of the Korean Institute of Gas
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    • v.10 no.2
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    • pp.61-67
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    • 2006
  • We developed the ultrasonic phased array technique for obtaining ultrasonic images of electrofusion joints of polyethylene piping. And we inspected 4 cases at fields with this technique. First case is for the 300 mm diameter polyethylene electrofusion joint by using 3.5 MHz phased array sensor, second is for the 350 mm diameter saddle electrofusion joint, third is for the 400 mm diameter electrofusion joints and the last one is for the 400 mm diameter piping joints which will be used at 300 kPa suppling pressure.

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Optimum Conditions of pH and Ca2+ Concentration for Electrofusion of Tobacco Protoplasts (담배 워형질체의 전기융합을 위하 pH 및 Ca2+ 농도 최적조건 설정)

  • 오인숙;소상섭;김환규
    • KSBB Journal
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    • v.13 no.4
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    • pp.399-403
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    • 1998
  • This study was carried out to optimize the concentration of Ca2+ and pH of fusion medium which affected electrofusion frequency of protoplasts isolated from Nicotiana tabacum L. (cv. BY4) mesophyll cells and callus. The protoplasts were electrofused in the fusion media containing two different Ca2+ concentrations and three different pH regions. Fusion frequency was lower in the fusion medium containing only 13% mannitol as osmotic stabilizer. However, higher degree of fusion frequency (47.3%) was observed in the fusion medium containing 50mM CaCl2 at pH 10.5 than any other conditions. Cell viability was decreased by Ca2+ and high pH treatment in the fusion media, while fusion frequency was increased. It is concluded that Ca2+ is involved in electrofusion of protoplasts.

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Field Inspection of Phase-Array Ultrasonic for PolyEthylene Electrofusion Joints

  • Kil, Seong-Hee;Jo, Young-Do;Yoon, Kee-Bong
    • Journal of the Korean Institute of Gas
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    • v.16 no.1
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    • pp.22-25
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    • 2012
  • Welding and/or fusion in polyethylene(PE) system made on site is focused on the control of the welding or fusion process to follow proper procedure. The process control is important, but it is not sufficient for the long term reliability of a pipe system. To achieve the rate of failure close to zero, Non Destructive Testing(NDT) is necessary in addition to joining process control. For electrofusion joints several non-destructive testing methods are available. The ultrasonic phased array technique is possible to detect various defects including wire deviations and regions with lack of fusion. In this studies, testing was carried to detect the defect after electrofusion joining of polyethylene piping is utilized by the ultrasonic phased array technique. From testing data, ultrasonic phased array technique is recommended as a reliable non-destructive testing method.

Non-Destructive Testing of Damaged Thermoplastic Pipes Electrofusion Joints Using Phased Array Ultrasonic (위상배열초음파를 이용한 손상된 열가소성 플라스틱배관 전기융착부 비파괴검사)

  • Kil, Seong-Hee;Kim, Byung-Duk;Kwon, Jeong-Rock;Yoon, Kee-Bong
    • Journal of the Korean Institute of Gas
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    • v.17 no.5
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    • pp.64-68
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    • 2013
  • Non destructive testing(NDT) methods of electrofusion(EF) joints of thermoplastics pipes are required for fusion joint safety and for the long term reliability of a pipe system. Electrofusion joints, which are joined at the proper fusion process and procedures, may encounter defects due to the difference of ovality between pipes and coupling, improper fusion process or porosity result from electrofusion joining. These defects can cause the failure of pipeline and by extension, they can be caused the limit to expand the use of plastics pipes. This paper studies inspection results using ultrasonic imaging method for damaged polyethylene electrofusion joints. Gas was leaking from 250mm diameter polyethylene electrofusion joints at February 2004 which was electrofused at December 1994 and operation pressure was 2.45kPa. First, surface inspection was conducted and then in order to find the types of defects examination using ultrasonic imaging method was performed. Lack of fusion and inappropriate inserting for polyethylene pipes into electrofusion coupling were found and causes of the gas leak were judged that misalignment and insert defect. Cutting inspection was performed and each inspection results were compared to. Results of ultrasonic imaging method and cutting inspection were the same.

Intersubgeneric Protoplast Fusion of Pelargonium aridum (Ligularia) and P.zonale(Ciconium) (Pelargonium aridum과 P. zonale 아속간의 원형질체융합)

  • 유순남
    • Korean Journal of Plant Tissue Culture
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    • v.22 no.6
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    • pp.311-316
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    • 1995
  • In an attempt to obtain intersubgeneric somatic hybrids of Pelargonium aridum and P.zonale, protoplast isolated from the two species were fused by using polyethylene glycol(PEG) and electorfusion methods. Protoplast were isolated from cotyledon and leaf tissues using MS medium containing 550 mM sucrose, 0.7% cellulase (Onozuka R-10) and 0.4% Macerozyme. The optimum number of protoplasts per mL of culture medium was 6 x 10$^4$. Protoplast fused by the electrofusion method were more active than by PEG method. Heterokaryotically fused protoplasts formed calli when cultured in MS medium containing 550 mM glucose, 1 to 2 mg/L NAA and 0.5 to 1 mg/L BA.

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STUDIES ON PRODUCTION AND EFFICIENT UTILIZATION OF LIVESTOCK EMBRYOS BY IN VITRO FERTILIZATION AND MICROMANIPULATION IV. NUCLEAR TRANSPLANTATION AND ELECTROFUSION FOR CLONING IN BOVINE FOLLICULAR OOCYTES

  • Chung, Y.C.;Kim, C.K.;Song, X.X.;Yoon, J.T.;Choi, S.H.;Chung, Y.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.6
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    • pp.641-645
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    • 1995
  • This study was conducted to develop a method for production of nuclear transplant bovine embryos using in vitro-matured (IVM) oocytes and to examine the effect of different conditions of electrofusion on fusion rate and developmental capacity of donor nucleus transplanted to enucleated oocytes. Eight- to sixteen-cell embryos derived from oocytes matured and fertilized in vitro used as donor blastomeres and IVM oocytes were used as recipient oocytes. Oocytes were enucleated immediately after 23-24 h IVM and then reconstituted with a donor blastomere in two different micromanipulation media. Fusion rate and subsequent development of the reconstituted oocytes was compared under the different electric stimuli and recipient oocyte ages. Success rate of enucleation was significantly higher in TCM-199 medium containing FCS than in DPBS. The high fusion rate(75-94%) and development (6.4-14.8%) to morulae and blastocyst (M + B) were obtained from 0.6-0.75 kV/cm DC voltage, although total cleavage was not different among the electric pulses. Most optimal condition of electric stimulation for fusion and development was 1 DC voltage of 0.75 kV/cm, in which 80.5% of oocytes were fused, 80.0% and 31.7% of which was cleaved and developed to M + B, respectively. No M + B was obtained from 1.2 kV/cm DC voltage regardless of pulse frequency. Recipint oocyte age at electrofusion greatly affected the cleavage and subsequent development to M + B, showing high rate at 40-41 h oocyte maturation. These results suggest that a suitable condition of electrofusion for donor nuclei derived from IVF may be 1-2 DC pulses of 0.7 kV/cm for $70{\mu}sec$ and that processing of a transplanted nucleus in IVM oocytes may be affected by maturation age of recipient oocytes.