• Title/Summary/Keyword: tape

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AC loss analysis and experimental evaluation of a high temperature superconductor (고온초전도선재의 교류손실 해석 및 실험)

  • Ryu, Kyung-Woo
    • Proceedings of the KIEE Conference
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    • 2001.11b
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    • pp.96-100
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    • 2001
  • Bi-2223 tapes have been developed for low-field power applications at liquid nitrogen temperature. When the Bi-2223 tapes are used in an application such as a power transmission cable or a power transformer, they are supplied with an AC transport current and exposed to an external magnetic field generated by neighboring tape's AC currents simultaneously. AC loss taking into account such real applications is a crucial issue for power applications of the Bi-2223 tapes to be feasible. In this paper, the transport losses for different AC current levels and arrangements of the neighboring tapes have been measured in a 1.5 m long Bi-2223 tape. The significant increase of the transport losses due to neighboring tape's AC currents is observed. An increase of the transport losses caused by a decrease of the Bi-2223 tape's critical current is a minor effect. The measured transport losses could not be explained by a dynamic resistance loss based on DC voltage-current characteristics in combination with the neighboring tape's AC currents. The transport losses do not depend on the frequency of the neighboring tape's AC currents but its arrangements in the range of small current especially.

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Optimization of Barium Titanate Slip for Tape Casting Using Design of Experiments

  • Kwon, Sung-Wook;Darsono, Nono;Yoon, Dang-Hyok
    • Journal of the Korean Ceramic Society
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    • v.43 no.9 s.292
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    • pp.519-526
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    • 2006
  • A full-factorial design of experiments with three input factors and two levels for each factor including center points was utilized for the preparation and characterization of twelve types of $BaTiO_3$ slips for tape casting. Ceramic powders with different particle sizes, different milling methods such as high energy milling and conventional ball milling, and two types of dispersant with different polymeric species were chosen as input factors in order to investigate their effects on slip and on green tape properties. Tape casting, a small rectangular-shaped K-square preparation, characterization and quantitative data analysis using statistical software were followed. Ceramic powder was the most significant among three input factors for the output responses of slip viscosity and green tape density, showing more favorable results with large particles than with very fine ones. In addition, high energy milling for only 30 min was more efficient than 24h of conventional ball milling in terms of powder dispersion and milling. The optimum condition based on the experimental results was a slip exposed to high energy milling with large ceramic particles along with a methylethyl acetate dispersant.

Effect of an External AC Magnetic field on Dynamic Resistance and Loss Characteristic in a Bi-2223 Tape (외부 교류자장이 Bi-2223테이프의 동저항 및 손실특성에 미치는 영향)

  • Ryu, Kyung-Woo;Choi, Byoung-Ju
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.5
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    • pp.473-477
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    • 2005
  • A Bi-2223 tape has been developed for power applications such as a fault current limiter, a power cable and a superconducting magnetic energy storage system. In such applications, the Bi-2223 tape carries time varying transport current and in addition experiences time varying external magnetic field. It is well known that the external magnetic field not only causes magnetization loss in the Bi-2223 tape, but also drastically increases transport loss due to a so-called 'dynamic resistance' We developed an evaluation setup, which can measure transport loss in external at magnetic fields. Using this equipment, we measured the dynamic resistances for various amplitudes and frequencies of an external at magnetic field perpendicular to the face in the tape. Simultaneously we investigated the effect of an external ac field on transport loss with different experimental conditions. This paper describes test results ana discussions on correlation between the dynamic resistance and the transport loss for the Bi-2223 tape.

A Study on Stability of Ag sheathed Bi-2229 tape and Cylindrical Stacking Conductor for HTS Cable (고온초전도 케이블용 은시스 Bi-2223 테이프 및 적층 도체의 안정성연구)

  • Lee, B.S.;Kim, Y.S.;Jang, H.M.;Back, S.M.;Kim, S.H.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1554-1556
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    • 2000
  • Normal zone propagation(NZP) characteristics were investigated on Ag sheathed multi filamentary Bi-2223 tape and cylindrical stacking conductor. The critical current($I_c$) of Ag sheathed Bi-2223 tape and cylindrical stacking conductor were 12 A, 63 A at 77 K, 0 T. Normal zone propagation(NZP) experiments with tape were conducted with refrigerator in temperature from 45 K to 77 K, 0 T. Cylindrical stacking conductor was molding with epoxy and experiments were conducted with adiabatic condition in $LN_2$. NZP velocities of tape with two condition of DC and AC were almost same at each temperature. Temperature ($T_1$) of tape with distance of 0.5 cm from heater was strongly climbed up to 95K and slowly decreased. NZP velocities of cylindrical stacking conductor were 1.9-2.4 cm/sec in $LN_2$.

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Analysis of Reel Tape Packing process conditions using DOE (실험계획법을 이용한 Reel Tape Packaging 공정조건 분석)

  • Kim, Jae Kyung;Na, Seung Jun;Kwon, Jun Hwan;Jeon, Euy Sik
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.2
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    • pp.105-109
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    • 2020
  • Today's placement machines can pick and place thousands of components per hour with a very high degree of accuracy. The packaged semiconductor chips are inserted into a carrier at regular intervals, covered with a tape to protect the chips from external impact, and supplied in a roll form. These packaging processes also progress rapidly in a consistent direction, affecting the peelback strength between the cover tape and carrier depending on the main process conditions. In this paper, we analyzed the main process variables that affect peelback strength in the reel tape packaging process for packaging semiconductor chips. The main effects and interactions were analyzed. The peelback strength range required in the packaging process was set as the nominal the best characteristics, and the optimum process condition satisfying this was derived.

Fabrication of $MgB_2$ tape with metal powder addition (금속분말이 첨가된 $MgB_2$ 선재의 제조 및 특성)

  • Ko, Jae-Woong;Yoo, Jai-Moo;Kim, Young-Kuk;Chung, Kook-Chae;Yoo, Sang-Im;Wang, Xio Lin;Dou, Shi Xue
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.1
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    • pp.1-4
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    • 2006
  • The $MgB_2$ tapes with several metal powder addition were fabricated by PIT method with or without heat treatment. The $J_c$ value of $5.600A/cm^2$ and $16.000A/cm^2$ at 4.2 K and 5 T were obtained for the $MgB_2$ tape and 10 vol % of Cu added $MgB_2$ tape without heat treatment respectively. The $J_c$ value of $8.000A/cm^2$ and $35,000A/cm^2$ at 4.2 K and 5 T were obtained for the $MgB_2$ tape and 10 vol. % of Al added $MgB_2$ tape with heat treatment, respectively. The $J_c-B$ curve shows enhancement in $J_c$ under magnetic field. which suggests enhancement in workability and grain connectivity with several metal powder addition.

Changes of the Excitability of the α-Motor Neuron by Taping (테이핑에 의한 α-운동 신경원 흥분도 변화)

  • Ahn, So-Yoon;Kim, Jong-Soon
    • The Journal of the Korea Contents Association
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    • v.8 no.6
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    • pp.167-174
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    • 2008
  • The application of tape is being widely used for treatment of the musculoskeletal disorders and injury prevention. The techniques of the tape application has been relied on empirical evidence in preference to the neurophysiological evidence. Thus, the mechanism of taping has to be elucidated further. In this study, we assessed the effect of the elastic and non-elastic tape upon the gastrocnemius ${\alpha}$-motor neuron excitability using the gastrocnemius H-reflex. The amplitude of the M-wave and H-reflex were measured across three conditions: before tape application, with tape and with the tape removed. No significant changes of the excitability of the ${\alpha}$-motor neuron were obtained across three condition, either in the elastic and non-elastic tape. This results were quite different with other recent studies, which needs to be explored further.

The Immediate Effects of Functional Taping on Pain, Muscle Strength, and Range of Motion of the Shoulder After Surgery in Patients With Rotator Cuff Tears (기능적 테이핑이 어깨둘레근 수술 후 환자의 어깨관절 통증과 근력, 관절가동범위에 미치는 즉각적 영향)

  • Mun, Yu-ri;Kim, Suhn-yeop
    • Physical Therapy Korea
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    • v.24 no.1
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    • pp.19-29
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    • 2017
  • Background: Patients after rotator cuff (RC) surgery experienced pain, weakness and limited of motion of the shoulder. Physical therapists have used heat therapy, electrotherapy, range of motion (ROM) exercise and other methods to treat patients after RC surgery. In addition, functional taping is also used to support joint movement and to increase shoulder joint stability. Objects: The purpose of this study was to determine the initial effects of functional taping using non-elastic tape on pain, strength and ROM of the shoulder following RC surgery. Methods: Forty-eight patients with who underwent RC surgery volunteered for this study. The subjects were randomly divided into an experimental group (EG, $n_1=25$) and a control group (CG, $n_2=23$). First, non-allergic tape was applied to the shoulder to prevent skin irritation. The EG applied functional taping using non-elastic tape and the CG applied sham taping using elastic tape. Assessment tools included the shoulder pain and disability index for functional activity score, visual analog scale for level of pain, shoulder muscle strength, hand grip strength and ROM testing. Results: Pain score in the both group significantly decreased (p<.05), and change in pain score of in the EG increased significantly than in the CG (p<.05). Shoulder strength and ROM in the both group significantly increased (p<.05). Especially external rotation and extension of the shoulder ROM in the EG increased significantly more than in the CG (p<.05), but the rate of change in the two groups showed no significant difference. Conclusion: These results suggest that functional taping using non-elastic tape was initially effective in decreasing pain score level in patients with RC surgery.

Effects of Tape Thickness and Inorganic Fillers on the Adhesion Properties of Double-sided Acrylic Adhesive Tape by Ultraviolet Curing (자외선 경화형 아크릴 양면 점착테이프의 두께 및 무기물 충전제 종류에 따른 접착특성)

  • Kim, Dong-Bok
    • Polymer(Korea)
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    • v.38 no.3
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    • pp.397-405
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    • 2014
  • To manufacture of high-performance semi-structural double-sided adhesive tape, 2-ethylhexyl acrylate (2-EHA) and acrylic acid (AAC) were used, and the syrup was prepared by UV irradiation in this study. The effects of the thickness, various inorganic filler contents, and filler types on the semi-structural properties of acrylic double-sided adhesive tape were investigated. The peel strength increased with increasing thickness and wetting time. In case of the thin thickness (under $250{\mu}m$) with decreasing true density of inorganic filler, the peel strength increased with increasing wetting time. The initial peel strength showed a higher value at a big size of inorganic filler, and the filler's size in adhesive tapes was confirmed by SEM images. The peel strength and dynamic shear strength increased as a proportional relationship with various inorganic fillers and contents, and these inorganic fillers in $0.1{\mu}m$ thickness indicated more effect on the dynamic shear strength of double-sided adhesive tape. From these results the thin acrylic double-sided adhesive tape determined to be use for applications as a high-performance semi-structural.

A new manufacturing method of all ceramic restoration using alumina tape and presentation of clinical cases

  • Oh, Nam-Sik;Kim, Eui-Seong;Lee, Keun-Woo;Han, Jung-Suk;Kim, Dae-Joon;Lee, Myung-Hyun
    • The Journal of Korean Academy of Prosthodontics
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    • v.38 no.6
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    • pp.800-805
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    • 2000
  • In an effort to facilitate fabrication procedure of all ceramic crowns, a novel preparation method for all ceramic crown using alumina tape was developed. The alumina tape having a uniform thickness was cast by using Doctor blade method. The physical properties of newly introduced alumina tape has biaxial flexure strength of $500\sim600MPa$. The value of toughness is $3.18\sim3,28MPa.m^{1/2}$ which corelates with fracture and the linear shrinkage rate of the alumina tape is 0.44% during core production. The marginal fitness of the alumina tape all-ceramic restoration with $90{!`}$shoulder margin had average marginal discrepancy at $78.3{\S}$ > and average marginal gap at $44.4{\S}$ >. At the marginal preparation of $135{!`}$deep chamfer, the average marginal discrepancy at $82.1{\S}$ > and the average marginal gap at $40.2{\S}$ > had been reported. This fabrication procedure of all ceramic crowns with alumina tapes is easier and less technical sensitive for dental technicians. After restoration with new all ceramic crowns we followed the patients 2 years later, there were no complications as porcelain fractures or periodontal disease. We had good esthetic clinical results with new all ceramic crowns.

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