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Effect of microstructure of surface glaze on printability of ink-jet printing ceramic tile (표면 유약 미세구조가 잉크젯 프린팅 도자타일의 인쇄적성에 미치는 효과)

  • Lee, Ji-Hyeon;Hwang, Kwang-Taek;Han, Kyu-Sung;Kim, Jin-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.28 no.6
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    • pp.243-249
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    • 2018
  • Ceramic tiles, which were manufactured through high-temperature firing process at over $1000^{\circ}C$, are widely used as interior and exterior materials for building construction due to their excellent durability and aesthetic of surface glaze. In recent years, the introduction of digital ink-jet printing in ceramic tiles for architectural use has been rapidly proceeding, and studies on the materials such as ceramic ink, ceramic pigment, glaze have been actively conducted. In this study, the effect of microstructure change of surface glaze on the printing properties of ceramic inks was investigated by micronization of kaolin, which is the raw material of surface glaze. Black ceramic ink was used for ink-jet printing on the surface glaze of ceramic tile to evaluate the printability by measuring the size and roundness of the printed ink dot. The relationship between microstructure change of surface glaze and printability of ceramic ink was also investigated by analyzing the surface roughness and internal micropore distribution of surface glaze.

The effect of silica composite properties on DLP-stereolithography based 3D printing (실리카 복합소재의 물성에 따른 DLP 3D printing 적용 연구)

  • Lee, Jin-Wook;Nahm, Sahn;Hwang, Kwang-Taek;Kim, Jin-Ho;Kim, Ung-Soo;Han, Kyu-Sung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.29 no.2
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    • pp.54-60
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    • 2019
  • Recently, various composite materials for additive manufacturing are interested to expand the application field of 3D printing. 3D printing technique was mainly developed using polymer, and ceramic materials for 3D printing are still in the early stage of research due to the requirement of high solid content and post treatment process. In this study, silica particles with various diameters were surface treated with silane coupling agent, and synthesized as silica composite with photopolymer to apply DLP 3D printing process. DLP is an additive manufacturing technology, which has high accuracy and applicability of various composite materials. The rheological behavior of silica composite was analyzed with various solid contents. After DLP 3D printing was performed using silica composites, the printing accuracy of the 3D printed specimen was less than about 3 % to compare with digital data and he bending strength was 34.3 MPa at the solid content of 80 wt%.

Results of radiofrequency catheter ablation in children and adolescent with tachyarrhythmia (소아 청소년 부정맥 환자에서 고주파 전극도자 절제술의 이용 성적)

  • Chang, Young Beom;Lee, Seung Hyun;Kang, Eun Young;Rhee, Kyoung-Suk;Joo, Chan Uhng
    • Clinical and Experimental Pediatrics
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    • v.50 no.11
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    • pp.1085-1090
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    • 2007
  • Purpose : Radiofrequency catheter ablation (RFCA) has become an effective therapeutic modality for treating pediatric tachyarrhythmias. Using conventional RFCA catheters, ablation of parahisian accessory pathways may be difficult and have high risk for heart block. We reviewed the efficacy and complications of the RFCA in children and adolescent with arrhythmias including parahisian accessory pathways. Methods : We studied 48 patients (aged 2 years to 20 years) who had undergone RFCA from August 2003 to March 2007. We reviewed clinical findings, electrophysiologic studies, RFCA data, complications, and follow-up results of the patients. Results : Mean age of the patients was 13.1 years. Numbers and types of arrhythmias (age, acute success rate) were as follows: 19 WPW syndrome including 5 parahisian accessory pathways ($13.7{\pm}4.6yr$, 18/19), 11 atrioventricular reentrant tachycardia with concealed bypass tract ($12.3{\pm}5.0yr$, 10/11), 13 atrioventricular nodal reentrant tachycardia ($12.6{\pm}4.4yr$, 13/13), 4 atrial flutter ($13.0{\pm}7.4yr$, 3/4), and 1 ventricular tachycardia (20 yr, 1/1). Associated cardiac structural lesion was not detected in 48 patients. The recurrence rate was 6.5%, and the final success rate was 93.8%. Conclusion : These results suggest that RFCA is a highly effective treatment method in children and adolescent with tachyarrhythmia.