과증식 동공막잔류 눈성인의 치료 : 3예

허준,양성원,양필중,고재웅 朝鮮大學校 附設 醫學硏究所 2007 The Medical Journal of Chosun University Vol.32 No.2

Purpose: Persistent pupillary membrane(PPM) can be classified as four types by means of its morphology. Type 2, which is attached to the lens, is very rare and can cause visual disability. We report 3 cases of type 2 PPM that shows a good visual acuity and cosmetic improvement after removal. Methods: We chose 3 female who showed a poor visual outcome and abnormal shaped pupil since a child. All of 3 case could be examined a hyperplastic persistent pupillary membrane by slit lamp biomicroscopy. Treatment was a surgical removal of PPM, and a surgical removal of PPM and cataract operation in one case of PPM with cataract. Results: All of 3 patient showed a good visual acuity and cosmetic improvement, Conclusion: Surgical management should be also considered to good visual acuity and cosmetic improvement to PPM observed in adult eye.

브레이징 온도 변화에 따른 ZrO2와 Ti-6Al-4V의 접합 특성

기세호,박상윤,허영구,정재필,김원중 大韓齒科補綴學會 2012 대한치과보철학회지 Vol.50 No.3

Purpose: In this study, brazing characteristics of ZrO2 and Ti-6Al-4V brazed joints with increasing temperature were investigated. Materials and methods: The sample size of the ZrO2 was 3 mm × 3 mm × 3 mm (thickness), and Ti-6Al-4V was 10 mm (diameter) × 5 mm (thickness). The filler metal consisted of Ag-Cu-Sn-Ti was prepared in powder form. The brazing sample was heated in a vacuum furnace under 5 × 10-6 torr atmosphere, while the brazing temperature was changed from 700 to 800℃ for 30 min. Results: The experimental results shows that brazed joint of ZrO2 and Ti-6Al-4V occurred at 700 - 800℃. Brazed joint consisted of Ag-rich matrix and Cu-rich phase. A Cu-Ti intermetallic compounds and a Ti-Sn-Cu-Ag alloy were produced along the Ti-6Al-4V bonded interface. Thickness of the reacted layer along the Ti-6Al-4V bonded interface was increased with brazing temperature. Defect ratios of ZrO2 and Ti-6Al-4V bonded interfaces decreased with brazing temperature. Conclusion: Thickness and defect ratio of brazed joints were decreased with increasing temperature. Zirconia was not wetting with filler metal, because the reaction between ZrO2 and Ti did not occur enough. 연구 목적: 온도 변화에 따른 ZrO2와 Ti-6Al-4V의 접합 특성에 대해 알아보기 위하여 새로운 브레이징 합금을 제조하고, 브레이징 온도가 접합 특성에 미치는 영향에 대하여 조사하고자 하였다. 연구 재료 및 방법: 본 연구에서 사용된 시편으로는 실험용 ZrO2 모재(ZirBlank-PS, Acucera, Inc., Gyeonggi-do, Korea)는 소결 전의 블록형태(65 mm × 36 mm × 12 mm (t))이며, 이를 잘라 사포(#2400)로 표면연마 후 소결하였다. 소결된 ZrO2 시편의 크기는 3 mm × 3 mm × 3 mm (t) 이다. Ti-6Al-4V 모재(Ti 6Al 4V ELI CG Bar, TMS, Washington, USA)는 직경 10 mm × 5 mm (t)를 사용하였다. 소결된 ZrO2와 Ti-6Al-4V의 접합을 위하여 브레이징 합금을 제조하였다. 시편을 3군으로 나누어A군은 700℃에서, B군은 750℃에서, C군은 800℃에서 각각 브레이징 하였다. 브레이징 부의 두께와 결함율의 측정은 각 군당 하나의 시편으로 각 시편 당 5회씩 반복 측정하여 평균값을 취하였다. 결과: 브레이징 합금을 사용하여 진공 브레이징을 수행한 결과 ZrO2 와 Ti-6Al-4V 는 700℃ - 800℃에서 양호한 접합을 보였다. 브레이징 후 브레이징 온도 변화에 따른 브레이징 부의 두께 및 결함율의 변화는SEM을 사용하여 측정하였다. 브레이징 온도가 700℃에서 800℃로 증가함에 따라 CuTi 금속간 화합물 층 및 Ti-Sn-Cu-Ag계 화합물 층의 두께는 각각 4.5 ㎛에서 10.3 ㎛로, 3.1 ㎛에서 5.0 ㎛로 증가되었다. 또한 브레이징 온도가 700℃에서 800℃로 증가함에 따라 브레이징 접합계면의 결함율은 ZrO2 및 Ti-6Al-4V 계면에서 각각25%에서 16.3%, 5%에서 1.5%로 감소되었다. 결론: 브레이징 온도가 700℃에서 800℃로 증가됨에 따라, 브레이징 접합계면의 결함율은 ZrO2 및 Ti-6Al-4V 계면에서 모두 감소되었다. 이는 결함부에서 ZrO2와 활성원소인 Ti과의 반응이 충분히 일어나지 않아서 브레이징 합금이 ZrO2에 웨팅되지 않은 것이 원인이라고 사료된다.

A study on electrical properties according to moisture absorption and drying of Epoxy/Micro Silica Composites for high voltage and heavy electric equipment

Heo In-Hoi(허인회),Im Chae-Woong(임채웅),Im Pil-Nam(임필남),Park Jae-Jun(박재준) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.10

High voltage-based heavy electric equipment (CT/PT, molded transformer, outdoor insulator, general bushing, recloser, etc.) Based on epoxy resin, two types of micro silica (W12EST, M10) are the most widely used fillers in the industrial field. A sample was prepared by filling contents 65wt% of W12est and M10 inorganic materials. There are three types of samples, and it was prepared through a drying process after moisture absorption and moisture absorption of three types of samples: epoxy resin, epoxy/surface-modified silica composite (W12est), and epoxy/surface-modified silica (M10). As the evaluation of the properties, the dielectric properties, mechanical tensile strength properties, and (±)HVDC dielectric breakdown properties, and the environmental resistance to outdoor insulation materials were evaluated for tracking and erosion properties.

Effects of different creep feed types on pre-weaning and post-weaning performance and gut development

Pil Seung Heo,김동혁,Jae Cheol Jang,Jin Su Hong,김유용 아세아·태평양축산학회 2018 Animal Bioscience Vol.31 No.12

Objective: This experiment was carried out to determine the effects of different creep feed types on suckling performance and further adjustments to solid feed after weaning. Methods: A total of 24 multiparous sows and their litters were allotted to one of three treatment groups: i) provided highly digestible creep feed (Creep), ii) provided a pig weaning diet (Weaner), and iii) provided sow feed (Sow) as creep feed until weaning. After weaning, a total of 96 piglets were selected for evaluation of post-weaning performance. Results: For pre-weaning performance, the Creep treatment led to a significantly higher feed intake from 14 to 28 d (p<0.05) and higher body weight gain from 21 to 28 d than piglets that were provided other diets. However, after weaning, the Weaner treatment yielded a significantly higher feed intake and average daily gain than other treatments from 0 to 14 d after weaning (p<0.05); Creep treatment tended to generate lower villus heights in the duodenum than the other treatments (p = 0.07). Conclusion: Highly digestible creep feed improved pre-weaning performance, but feed familiarity and grain-based creep feed improved post-weaning performance.

Industry-Technology Roadmap in the Field of Next-generation Convergent Contents

Pil-sun Heo,Myung-hwan Rim,Yong-jae Park 한국콘텐츠학회 2010 한국콘텐츠학회 종합학술대회 논문집 Vol.2010 No.12

Survey on Horticultural Traits of Native Herbs in Southern Coastal Area of Korea

Jae-ok Park,Hye-sung Cho,Moon-young Park,Youn-seop Cho,Guek-pil Bang,Buk-gu Heo 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Industry-Technology Roadmap in the Field of Next-generation Convergent Contents

Pil-sun Heo,Myung-hwan Rim,Yong-jae Park 한국콘텐츠학회 2010 ICCC International Digital Design Invitation Exhib Vol.2010 No.12

강직성 척추염 환자에서 발생한 경추골절(1례 보고)

정재윤,허정필,서형연 대한골절학회 1997 대한골절학회지 Vol.10 No.1

The patient with ankyiosing spondylitis is easily apt to be fractured in spine regions, even by minor trauma due to severe limitation of spinal motion and progressive osteoporosis. In those patients, accurate reduction and rigid internal or external immobilization and postoperative early mobilization is very important to treat or prevent the spinal cord injury. Untill now halo-vest immobilization or posterior fusion is widely aceepted method of treatment and there was no report about anterior plate fixation. Authors fused the patient anterorily with tricortical iliac graft and plate with compression mechanism to gel early solid bony union, to increase the immediate rigid stability, to correct the deformity and to mobilize the patient early as possible. We have experienced a 54-year-old male patient with ankylosing spondylitis complicating traumatic fracture of the cervical spine at C6-7 and follow up study of 9 years was possible. The patient was injured by minor pedestrian motor vehicle accident. Pre-injury activity was normal, and neurological status was Frankel grade D just after trauma however, it was aggrevated to Frankel grade C paraplegia during position change before operation. The patient was anesthesized with aid of the tracheostomy. Anterior plate fixation was performed with tricortical iliac strut bone graft and plate. And then early mobilization was encouraged with SOMI brace. Neurological status was improved and there was no periand post-operative complications. Systemic complications was not occurred also. Re-displacement at fracture site with minimal screw loosening during follow up period was observed however, solid bony union was obtained at post-operative 3 months without further displacement or loosening. We report this case with review of literatures for good clinical result of anterior fusion with plate during long term follow up period of 9 years.

강직성 척추염에 합병된 경추골절의 전방내고정술에 의한 치료

정재윤,허정필,이기태 대한척추외과학회 1997 대한척추외과학회지 Vol.4 No.1

Study Design : The clinical experience of anterior plate fixation for cervical spine fracture in ankylosing spondylitis was descrived and the result was discussed with literatural reports. Objectives : To determine the efficacy and stability of anterior fusion with plate fixation as a treatmen option of cervical spine fractures in ankylosing spondylitis. Summary of Literature Review : Halo-vest immobilization or posterior fusion were widely accepted method of treatment for cervical spine fracture of ankylosing spondylites. However, there was only a few report about anterior plate fixation. Mothods and Methods : Three patients with ankylosing spondylitis who were underwent operation for cervical spine fracture by anterior fusion and plate fixation. General description of pre- and postoperative clinical, radiological and neurological status were done. Results : Follow-up study at one to nine years, post operatively, all patients showed good fusion, fully recovered neurological status. And loosening or failure of plate and screws were not observed. Conclusion : Bases on the experience, we recommend the anterior fusion with plate fixation for a treatment of cervical spine fracture in the patient with ankylosing spondylitis.

PZT를 이용한 계면 교차 방향 방사형 마이크로믹서

허필우(Pil-Woo Heo),김덕종(Deok-Jong Kim),김재윤(Jae-Yun Kim),박상진(Sang-Jin Park),윤의수(Eui-Soo Yun),고광식(Kwang-Sik Koh) 한국유체기계학회 2003 유체기계 연구개발 발표회 논문집 Vol.- No.-

Micromixer plays an important role in Bio-MEMS or μ-TAS. Mixing is generally generated by turbulence and interdiffusion of two fluids. Because of low Reynolds number(Re << 2000) in μ-channel, it is difficult to generate turbulence, so mixing mainly depends on interdiffusion. Thus long channel distance is required to mix two different fluids. To reduce the channel length required for mixing, we propose the a new active μ-mixer that two fluids are effectively mixed in μ-channel by the ultrasonic wave which is generated by PZT. The ultrasonic wave is radiated into a chamber in the cross-section directional direction to interface with the two fluids. The two fluids are positioned one on top of the other. Mixing state is measured by the changing of color due to the reaction of NaOH and phenolphtalein.