• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.604-605
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• 2006

Recently the Marangoni convention is supposed to be an important phenomenon that significantly affects the solidification. For understanding the Marangoni convection mechanism, visualizing the convention phenomenon of molten tin with ultrasonic has been conducted. This paper reports developing a tracer material of micro metal balloon that is used in the molten system. We have succeeded in coating the surface of Shirasu-ballons with nickel by plating process. The obtained metal balloon is spherical and some characterizations were conducted.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.703-704
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• 2010

• Journal of Korean Neurosurgical Society
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• 제49권3호
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• pp.157-162
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• 2011

Objective : Vasospasm of cerebral vessels remains a major source of morbidity and mortality after an aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to evaluate the safety and efficacy of transluminal balloon angioplasty (TBA) for SAH-induced vasospasm. Methods : Eleven patients with an angiographically confirmed significant vasospasm (>50% vessel narrowing and clinical deterioration) were studied. A total of 54 vessel segments with significant vasospasm were treated by TBA. Digital subtraction angiography was used to confirm the presence of vasospasm, and TBA was performed to dilate vasospastic arteries. Medical and angiographic reports were reviewed to determine technical efficacy and for procedural complications. Results : TBA using Hyper-Glide or Hyper-Form balloons (MicroTherapeutics, Irvine, CA) was successfully accomplished in 88.9% vasospastic segments (48 of 54), namely, in the distal internal carotid artery (100%, n=7), the middle cerebral artery (100%), including the M1 (n=10), M2 (n=10), and M3 segments (n=4), in the vertebral artery (100%, n=2), basilar artery (100%, n=1), and in the anterior cerebral artery (ACA), including the A1 (66%), A2 (66%), and A3 segments (100%). Vessel diameters significantly increased after TBA. There were no cases of vessel rupture or thromboembolic complications. GCS at one day after TBA showed an improvement in all patients except one. Conclusion : This study suggests that TBA using Hyper-Glide or Hyper-Form balloons is a safe and effective treatment for subarachnoid hemorrhage-induced cerebral vasospasm.

• Korean Circulation Journal
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• 제54권8호
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• pp.499-512
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• 2024

Background and Objectives: Arterial dissection during endovascular therapy rarely occurs but can be lethal. A fabric-based covered graft stents yield poor clinical outcomes. A novel balloon-expandable stent with biodegradable film graft for overcoming these issues was evaluated in a rabbit iliac artery model. Method: Eighteen rabbits with iliac artery dissections were induced by balloon over-inflation on angiography (Ellis type 2 or 3) and treated using the test device (3.0×24 mm). Subsequently, survived twelve animals underwent histologic examinations and micro-computed tomography (CT) at 0, 2, 4, and 8 weeks and 3, 6, 9, and 12 months and angiography at one-year. Results: There were no adverse cardiovascular events during the one-year. Early-stage histologic examination revealed complete sealing of disrupted vessels by the device, exhibiting mural hematoma, peri-stent red thrombi, and dense infiltration of inflammatory cells. Mid- and long-term histologic examination showed patent stents with neointimal hyperplasia over the stents (% area stenosis: 11.8 at 2 weeks, 26.1 at 1 month, 29.7 at 3 months, 49.2 at 9 months, and 51.0 at 1 year), along with mild peri-strut inflammatory response (Grade: 1-2 at mid-term and 0-1 at long-term). The graft film became scarcely visible after six months. Both CT and angiography revealed no instances of thrombotic occlusion or in-stent restenosis (% diameter stenosis: 5.7 at 2 weeks, 12.3 at 1 month, 14.2 at 3 months, 25.1 at 9 months, and 26.6 at 1 year). Conclusions: The novel balloon-expandable stent with a biodegradable film graft demonstrates feasibility in managing severe artery dissection and preventing lethal vascular events in animal model.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제25권2호
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• pp.175-181
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• 2023

Objective: Endovascular treatment of cerebrovascular diseases is often challenging due to small caliber, tortuous distal vessels. Several devices and techniques have evolved to overcome these challenges. Recently, a low profile dual lumen microballoon catheter, specifically designed for distal navigation is employed for neurovascular procedures. Due to its recent advent, scarce data is available on clinical utility and safety of Scepter Mini. The aim of this case series is to report our initial experience with Scepter Mini in the management of various cerebrovascular diseases. Methods: All interventional neurovascular cases performed using Scepter Mini between January 2020 till April 2021 were included. Data regarding patient demographics, procedural details and complications was retrospectively collected from patient's electronic medical record and procedure reports. Results: Total twelve embolization procedures were performed in eleven patients, including six brain arteriovenous malformation, two dural arteriovenous fistula, one vein of Galen malformation and three hyper-vascular glomus tumor embolizations. All procedures were successfully performed with adequate penetration of the embolic agent. Complete embolization was performed in six procedures, while intended partial embolization was performed in the rest of procedures. Scepter Mini was solely used in ten procedures, however in the other two embolization procedures it was used as an additional conjunct tool to complete the intended embolization. No balloon related complication was observed in any procedure. Conclusions: Scepter Mini dual lumen microballoon catheter is safe and feasible for delivery of liquid embolic agents for cerebrovascular embolization procedures.

• 화약ㆍ발파
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• 제25권2호
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• pp.61-70
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• 2007

2000년도 초반 한국의 대규모 석회석 광산에서는 ANFO의 단점을 보완하고 생산성 향상을 위하여 벌크 에멀젼 폭약을 도입하였다. 벌크 에멀젼 폭약이 상용화됨에 따라 전체적인 발파효율은 향상되었나, 폭발열 및 가스량이 부족하여 동일 장약량 적용 시 moving 및 heaving이 감소하는 경향이 나타났다. 따라서 기존 벌크 에멀젼의 발파효율을 증가시키기 위한 방안으로 chemical gassing 기술을 도입하였다. chemical gassing이란 기존 벌크 에멀젼의 예감제로 사용되는 GMB(Glass Micro Balloon)를 gassing agent로 대체하여 화학적으로 예감화하는 기술을 말한다 본 논문에서는 한국의 대규모 석회석광산에서 성공적으로 chemical gassing을 적용한 사례를 소개하였으며, 발파효율 및 작업성 등을 비교 평가 결과 상부파쇄도 및 toe 개선효과, moving의 향상을 확인할 수 있었다.

• 전기학회논문지
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• 제65권1호
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• pp.135-141
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• 2016

Recently, the needs for the development and application of marine robots are increasing as marine accidents occur frequently. However, it is very difficult to acquire the information by utilizing marine robots in the marine environment. Therefore, the needs for the researches of sensor networks which are composed of underwater, surface and aerial robots are increasing in order to acquire the information effectively as the information from heterogeneous robots has less limitation in terms of coverage and connectivity. Although various researches of the sensor network which is based on marine robots have been executed, all of the underwater, surface and aerial robots have not yet been considered in the sensor network. To solve this problem, a collaborative control method based on the acoustic information and image by the sonars of the underwater robot, the acoustic information by the sonar of the surface robot and the optical image by the camera of the static-floating aerial robot is proposed. To verify the performance of the proposed method, the collaborative control of a MUR(Micro Underwater Robot) with an OAS(Obstacle Avoidance Sonar) and a SSS(Side Scan Sonar), a MSR(Micro Surface Robot) with an OAS and a BMAR(Balloon-based Micro Aerial Robot) with a camera are executed. The test results show the possibility of real applications and the need for additional studies.

• 보존과학회지
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• 제30권1호
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• pp.103-109
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• 2014

본 연구는 토 도기 보존 처리과정에 있어서 결손부위를 복원하는 재료의 문제점과 단점 등을 보완한 재료를 개발하고자 하였다. 우선 기존 재료의 문제점으로는 높은 수축률과 낮은 접착력으로 인한 2 차 파손의 문제, 심한 황변현상으로 인한 이질감의 문제, 재료의 비가역성으로 인한 재용해의 문제 및 높은 강도로 인한 가공성의 문제, 작업 과정 중 긴 경화 시간으로 인한 처짐 현상 및 도구나 장갑에 묻어 유물의 표면을 오염시키는 문제 등이 있다. 이러한 문제점을 해결하기 위해 현재 사용되고 있는 토 도기 복원 재료들 중 Epoxy 수지를 중심으로 종류 및 물성을 파악한 후 개발 목표를 설정하였다. 개발 된 Epoxy는 5 분 내외에 경화가 이루어지는 토기 복원용 Epoxy Putty이다. 토기 복원 방법에 있어서 Epoxy Putty의 경우 페이스트(Paste) 형태로 빠르게 경화되어 작업의 편리성을 높였으며, 표면 오염 등의 단점을 보완하였다. 또한 Epoxy 원액에 백색의 Micro-balloon을 사용함으로 인해 Coloring에 용이하고 경량화하도록 하였으며, 저수축 및 가공성이 우수한 복원 재료를 개발하였다.

• 보존과학회지
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• 제31권2호
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• pp.105-114
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• 2015

본 연구에서는 유물의 보존 처리 과정에서 결손 부위의 복원을 위해 적용 가능한 다목적용 복원재료로써 Epoxy Putty를 개발하고자 하였다. 기존에 사용되고 있는 재료의 물성에서 드러난 높은 강도로 인한 가공성의 문제, 작업 과정 중 긴 경화 시간으로 인한 처짐 현상, 도구나 장갑에 묻어 유물의 표면을 오염시키는 등의 문제점을 해결하기 위해, 1차적으로 현재 많이 사용되고 있는 Epoxy Putty 형태의 복원 재료 물성을 파악한 후 이를 비교 대상으로 선택하여 경화제와 충전제의 종류에 따른 Epoxy Putty를 개발하였다. 개발 된 Epoxy Putty는 기존 재료의 문제점 해결 및 유사한 물성을 지니기 위해 성상(性狀)이 다른 2종의 경화제를 선정하여 물성 실험을 실시하였다. 경화제로는 Mercaptan 계열의 경화제와 Aliphatic amine 계통의 경화제 2종을 선택하여 개발하였다. 연구 결과 2종 모두 Paste 형태로 경화 시간은 5~10분 내외로 기존 재료에 비해 약 3~10배 정도 짧아 작업의 편리성을 높였으며, 가공성을 높이기 위한 마모율은 약 3배 정도 향상시켜 쉽게 사용할 수 있도록 하였으며, 작업 중 발생하는 표면 오염 등의 단점을 보완하기 위해 충전제로 백색의 Micro-balloon을 첨가하여 사용 중 손에 묻어 나오는 끈적거리는 현상을 줄여주었을 뿐만 아니라 Coloring, 경량성, 절삭력 등이 높은 저수축 및 가공성이 우수한 다목적 복원 재료를 개발하였다.

• 대기
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• 제15권3호
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• pp.149-153
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• 2005

A balloon-borne Optical Particle Counter (hereafter "OPC Sonde"), which was developed by the atmospheric research group of Nagoya University, is used for getting the information of vertical profile of particle size and concentration in Anmyeon ($36^{\circ}32^{\prime}N$ $126^{\circ}19^{\prime}E$) on 18 March 2005. A range of five different particle sizes is shown in the vertical profile of aerosol number density estimated from the OPC Sonde. It was found that small size particles have vertically larger aerosol number density than relatively big ones. For all size ranges the vertical aerosol number density shows a decreased pattern as the altitude becomes higher. The aerosol number density of $0.3{\sim}0.5{\mu}m$, $0.5{\sim}0.8{\mu}m$, $0.8{\sim}1.2{\mu}m$ size ranges at the 10km height, which is the tropopause approximately, are $1,000,000ea/m^3$, $100,000ea/m^3$, $10,000ea/m^3$ respectively. The data of OPC Sonde are also compared with the data of PM10 $\beta$-ray) and Micro Pulse Lidar which are operating at Korea Global Atmosphere Watch Observatory in Anmyeon.