The evaluation of healing patterns in surgically created circumferential gap defects around dental implants according to implant surface, defect width and defect morphology

임세웅,홍지연,채경준,정의원,김창성,이용근,조규성,김종관,최성호 대한치주과학회 2008 Journal of Periodontal & Implant Science Vol.38 No.2

Purpose: The aim of this study was to evaluate the factors affecting healing patterns of surgically created circumferential gap defects around implants in dogs. Materials and Methods: In four mongrel dogs, all mandibular premolars were extracted. After 8 weeks of healing periods, implants were submerged. According to the surface treatment, turned surface was designated as a group A and rough surface as a group B. In each dog, surgical defects on the left side were made with a customized tapered step drill and on the right with a customized paralleled drill. Groups were also divided according to the width of the coronal gaps: 1.0mm, 1.5mm, or 2.0mm. The dogs were sacrificed following 8 weeks and the specimens were analyzed histologically and histomorphometrically. Results: During the postoperative period, healing was uneventful and implants were well-maintained. As the size of the coronal gap was increased, the amount of bone-to-implant contact was decreased. The bone healing was greater in rough surface implants compared to the turned ones. About the defect morphology, tapered shape showed much bone healing and direct bone to implant contact even in the smooth surface implants. Conclusion: Healing of the circumferential defect around dental implant is influenced by the implant surface, defect width and the morphology of the defect. When using rough surface implants, circumferential gap defects within 2 mm do not need any kinds of regenerative procedures and the healing appeared to be faster in the tapered defect morphology than the paralleled one. (J Korean Acad Periodontol 2008;38:385-394) Purpose: The aim of this study was to evaluate the factors affecting healing patterns of surgically created circumferential gap defects around implants in dogs. Materials and Methods: In four mongrel dogs, all mandibular premolars were extracted. After 8 weeks of healing periods, implants were submerged. According to the surface treatment, turned surface was designated as a group A and rough surface as a group B. In each dog, surgical defects on the left side were made with a customized tapered step drill and on the right with a customized paralleled drill. Groups were also divided according to the width of the coronal gaps: 1.0mm, 1.5mm, or 2.0mm. The dogs were sacrificed following 8 weeks and the specimens were analyzed histologically and histomorphometrically. Results: During the postoperative period, healing was uneventful and implants were well-maintained. As the size of the coronal gap was increased, the amount of bone-to-implant contact was decreased. The bone healing was greater in rough surface implants compared to the turned ones. About the defect morphology, tapered shape showed much bone healing and direct bone to implant contact even in the smooth surface implants. Conclusion: Healing of the circumferential defect around dental implant is influenced by the implant surface, defect width and the morphology of the defect. When using rough surface implants, circumferential gap defects within 2 mm do not need any kinds of regenerative procedures and the healing appeared to be faster in the tapered defect morphology than the paralleled one. (J Korean Acad Periodontol 2008;38:385-394)

The evaluation of healing patterns in surgically created circumferential gap defects around dental implants according to implant surface, defect width and defect morphology

Im, Se-Ung,Hong, Ji-Youn,Chae, Gyung-Joon,Jung, Ui-Won,Kim, Chang-Sung,Lee, Yong-Keun,Cho, Kyoo-Sung,Kim, Chong-Kwan,Choi, Seong-Ho Korean Academy of Periodontology 2008 Journal of Periodontal & Implant Science Vol.38 No.2

Purpose: The aim of this study was to evaluate the factors affecting healing patterns of surgically created circumferential gap defects around implants in dogs. Materials and Methods: In four mongrel dogs, all mandibular premolars were extracted. After 8 weeks of healing periods, implants were submerged. According to the surface treatment, turned surface was designated as a group A and rough surface as a group B. In each dog, surgical defects on the left side were made with a customized tapered step drill and on the right with a customized paralleled drill. Groups were also divided according to the width of the coronal gaps: 1.0mm, 1.5mm, or 2.0mm. The dogs were sacrificed following 8 weeks and the specimens were analyzed histologically and histomorphometrically. Results: During the postoperative period, healing was uneventful and implants were well-maintained. As the size of the coronal gap was increased, the amount of bone-to-implant contact was decreased. The bone healing was greater in rough surface implants compared to the turned ones. About the defect morphology, tapered shape showed much bone healing and direct bone to implant contact even in the smooth surface implants. Conclusion: Healing of the circumferential defect around dental implant is influenced by the implant surface, defect width and the morphology of the defect. When using rough surface implants, circumferential gap defects within 2 mm do not need any kinds of regenerative procedures and the healing appeared to be faster in the tapered defect morphology than the paralleled one.

공동주택 콘크리트 균열의 하자판정 기준

정지성(Jeong, Ji-Seong),유용신(Yu, Yong-Sin),윤호빈(Yoon, Ho-Bin),정인수(Jung, In-Su),이찬식(Lee, Chan-Sik) 대한건축학회 2012 大韓建築學會論文集 : 構造系 Vol.28 No.11

The number of apartment housing increased rapidly due to housing supply promotion policy carried out at the late 1980’s. The disputes over defect of apartment building and accrued lawsuits also increase due to the various causes including quality of apartment and they incurs the social and economic problem. Crack defect is the most popular type of defect for the reinforced concrete works. The defect repair cost for the reinforced concrete work occupies about 50% of them for whole works. Lawsuits without any negotiation and arbitration for the defect spread throughout the country as there is not any judgement standard for the defect. Minimizing disputes and lawsuits caused by defect of concrete crack, defect judgement standard should be established. To suggest the standard of tolerable crack defect, this study examined the related standards, legal judgement cases, judgement standard alternatives, and expert interviews, questionaire survey. As the result, the tolerable crack range for the structural safety and the durability as 0.3㎜~0.4㎜ and the watertightness tolerable crack width as 0.1㎜, and the appearance tolerable crack width as 0.2㎜ are suggested.

미세 패턴 자동 검사 시스템

김성우,류지열,임재환,배종일 제어로봇시스템학회 2011 제어로봇시스템학회 국내학술대회 논문집 Vol.2011 No.5

In this paper, we propose a new automatic defect test system for a fine pattern COF (chip-on-film). The developed system detects automatically various defects of a COF with width of less than 24㎛ and pitch of less than 30㎛. The defects contain variety of defects such hard open, hard short, mouse bite (soft open) and near short (soft short). Basic principle for detecting these defects investigates voltage differences between defective and defect-free patterns using radio frequency resonator. This resonator amplifies this difference for the various cases. This approach based on an automatic detect test system can fairly save COF test costs as compared to conventional COF tests.

열화상 기술에 의한 M.C 나일론의 내부 결함에 대한 평가

한정섭(Jeong-Seb Han) 한국해양공학회 2009 韓國海洋工學會誌 Vol.23 No.2

Infrared thermography was used to determine the location, size, and depth of defects under the surface of M.C nylon. Defects were created in a specimen by back-drilling circular holse. These defects were located at the maximum temperature difference that occurred. The size of the defects could be calculated by means of the full width at half of the maximum temperature difference. The depth of a defect could be calculated by the peak time and the maximum temperature difference. The maximum temperature difference between a defect and normal part was decreased with the depth of the defect. And the peak time also slowly appeared with the depth of the defect.

미세 피치 칩 온 필름의 결함 검출을 위한 자동 시스템 개발

류지열(Jee-Youl Ryu) 한국정보기술학회 2011 한국정보기술학회논문지 Vol.9 No.1

This paper presents a novel automatic detection system for COF(chip-on-film) with fine width of less than 24㎛ and fine pitch of less than 30μm. Developed system can automatically detect variety of defects such hard open, hard short, mouse bite (soft open) and near short (soft short). Basic principles are to detect these defects determining voltage difference of 0-volt using radio frequency resonator. This resonator amplifies resistance variations of interconnection from defects of fine patterns. It detects voltage differences between defect-free and defect cases. We believe that this approach based on an automatic detection system can fairly save COF costs in production testing as well as in the measurement system as compared to conventional COF test approaches.

적외선 열화상을 이용한 콘크리트 구조물 내외부 결함 평가

박준희(Jun-Hee Park),이준수(Jun-Su Lee),정하린(Ha-Rin Jeong),이선곤(Sun-Kon Lee),김주형(Joo-Hyung Kim) 한국기계가공학회 2024 한국기계가공학회지 Vol.23 No.2

This study aims to detect defects using infrared thermography, measuring their size accurately for diagnosis and maintenance. It utilizes infrared thermal images for detection and applies the Gauss function to temperature distribution for quantitative evaluation, considering camera specifications such as Instantaneous Field of View (IFOV). The test object had both external and internal defects. The accuracy in evaluating external defects was within a 7.5% error rate regardless of depth, and for internal defects, except those 30-40mm deep, the error rate stayed below 8.6%.

A new insight into the structural modulation of graphene oxide upon chemical reduction probed by Raman spectroscopy and X-ray diffraction

Chadha Neakanshika,Sharma Rahul,Saini Parveen 한국탄소학회 2021 Carbon Letters Vol.31 No.6

Lately, Raman spectroscopy has become powerful tool for quality assessment of graphene analogues with identifcation of intensity ratio of Raman active D-band and G-band (ID/IG ratio) as a vital parameter for quantifcation of defects. However, during chemical reduction of graphitic oxide (GrO) to reduced GrO (RGrO), the increased ID/IG ratio is often wrongly recognized as defect augmentation, with “formation of more numerous yet smaller size sp2 domains” as its explanation. Herein, by giving due attention to normalized peak height, full-width half-maxima and integrated peak area of Raman D- and G-bands, and compliment the fndings by XRD data, we have shown that in-plane size of sp2 domains actually increases upon chemical reduction. Particularly, contrary to increased ID/IG ratio, the calculated decrease in integrated peak area ratio (AD/AG ratio) in conjunction with narrowing of D-band and broadening of G-band, evinced the decrease in in-plane defects. Finally, as duly supported by reduction induced broadening of interlayer-spacing characteristic XRD peak and narrowing of~43° centered XRD hump, we have also shown that the sp2 domains actually expands in size and the observed increase in ID/IG ratio is indeed due to increase in across-plane defects, formed via along-the-layer slicing of graphitic domains.

Conceptual design of 240 mm 3 T no-insulation multi-width REBCO magnet

Kibum Choi,Jung Tae Lee,Jeseok Bang,Uijong Bong,Jeonghwan Park,Seungyong Hahn 한국초전도.저온공학회 2019 한국초전도저온공학회논문지 Vol.21 No.3

A rare-earth barium copper oxide (REBCO) superconducting magnet was designed using no-insulation (NI) and multi-width (MW) winding techniques. The proposed magnet is comprised of 58 REBCO-wound single pancake coils with a bore size of 240 mm. When the magnet is operated at 20 K, the center magnetic flux density is designed to reach 3 T with an operational current of 169.55 A, 70 % of its critical current. The critical current was evaluated using experimental data of a short REBCO conductor sample. The designed magnet was then simulated using FEM software with uniform current density model. Magnetic field and mechanical properties of the magnet are evaluated using the simulated data. This magnet was designed as one of the base designs for the project “Tesla-Level Magnets with Large Bore Sizes for Industrial Applications” which was initiated in 2019, and will be wound using REBCO wires with the defect-irrelevant-winding (DIW) technique incorporated to reduce the overall manufacturing cost.

Conceptual design of 240 mm 3 T no-insulation multi-width REBCO magnet

Choi, Kibum,Lee, Jung Tae,Bang, Jeseok,Bong, Uijong,Park, Jeonghwan,Hahn, Seungyong The Korea Institute of Applied Superconductivity a 2019 한국초전도저온공학회논문지 Vol.21 No.3

A rare-earth barium copper oxide (REBCO) superconducting magnet was designed using no-insulation (NI) and multi-width (MW) winding techniques. The proposed magnet is comprised of 58 REBCO-wound single pancake coils with a bore size of 240 mm. When the magnet is operated at 20 K, the center magnetic flux density is designed to reach 3 T with an operational current of 169.55 A, 70 % of its critical current. The critical current was evaluated using experimental data of a short REBCO conductor sample. The designed magnet was then simulated using FEM software with uniform current density model. Magnetic field and mechanical properties of the magnet are evaluated using the simulated data. This magnet was designed as one of the base designs for the project "Tesla-Level Magnets with Large Bore Sizes for Industrial Applications" which was initiated in 2019, and will be wound using REBCO wires with the defect-irrelevant-winding (DIW) technique incorporated to reduce the overall manufacturing cost.