• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.53-59
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• 2006

This paper presents the IR-Lamp test results of evaluating heat protection performance and measuring of mechanical/thermal properties in the heat protection material of missile external surface. The results showed that increasing the contents of microballoons improved the heat protection performance, but the mechanical properties were deteriorated. Among the kinds of microballoons, Epoxy/Phenolic Microballoons mixture showed the best mechanical properties and low thermal conductivity. Epoxy/Cork mixture showed the best heat protection in the IR-Lamp test, though it has low mechanical properties and high thermal conductivity.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.2
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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.

• 보존과학연구
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• s.8
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• pp.13-34
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• 1987

A large number of metallic relics were excavated by a team of Kyungsang University museum (Nov. 25, 1985 - Jan. 29, 1986) from the groups of tombs located at No. 9 Mountain,Okchun Village, Sungsan-Ri, Ssangchak-Myon, Hyopchun-Kun, Kyungsangnam-Do which are believed to date back to Kaya period. The Research Institute of Cultural Properties was in charge performing scientific conservation and restoration for the iron cuirass and horse halmet (for one year and seven months, Feb. '86 - Sep. '87)The scientific processing for them are as follows :1. Taken Photo and record the actual conditions prior to conservation.2. Taken radiography3. Elimate Goethite ($\alpha$-FeOOH) layer on the surface using Air-brasive, remaining Magnetite ($Fe_3O_4$) layer.4. Treat to dechlorinize with 3% Sodium-Sesquicarbonate5. Protected the relics with Ruscoat acryl resin using vacuum infiltration method.6. Joint the sherd using Araldite and Microballoon mixture.7. Restored missing parts by Araldite SV 427 and HV 4278. Made record and taken photo after restoration Several hundred of sherds of relics, small or large, were restored by assortment which this method for the purpose of contributing to the further study of ancient Kaya history.* Conservator, National Research Institute of Cultural Properties.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.129-137
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• 2006

This paper studies the effects of the swirl for the variation of intake port configuration that is key parameters in the flow field of direct injection diesel engines. In-cylinder flow characteristics is known to have significant effects on air-fuel mixing, combustion, and emissions. To investigate the effects of the swirl flow, various rpm(250, 500, 750) and two different intake port were used. And to evaluate the swirl motion in the flow field visualization engine, steady state flow test was conducted. Helical port intake port and SCV(Swirl Control Valve) were selected as the design parameters to increase the swirl flow and parametric study was performed. In the case of non-SCV, intake flow rate and non-dimensional swirl ratio were higher than those of SCV for the swirl head type. So, we could strengthen the swirl in the flow field with the swirl head type and don't using SCV. From the results of steady state flow test, non-swirl head type has the most good advantage for intake flow rate, and also the flow rate could be increased by using the SCV slightly. The effects of the type of engine head on intake air flow capability are dominant with respect to the existence of the SCV. We could measure the qualitative grade of swirl by capturing the scattering signal of microballoon from ICCD camera in the visualization diesel engine.

• Journal of Conservation Science
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• v.35 no.5
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• pp.453-469
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• 2019

The celadon jar with inscription of 'the Fourth Sunhwa Year' is an important chronology that shows the conditions of production of the early celadon due to the inscription on the bottom including its purpose, application, and the producer. This celadon jar has been restored several times in the past. However, concerns over the structural stability, such as the separation and level differences in the joined cracks, have risen because of the aging of the repair materials, which were subjected to various environmental changes over a long time. By examining the conditions of preservation, the major damage was identified as the '入' shaped crack on the front, the 'V' shaped restored part and the crack on its left side, and the 'J' shaped crack on the back side. In the past, the cracks were found to be joined using a refined lacquer containing camphor, drying oil, rosin, etc. mixed with soil powder. The joint line was repainted with the refined lacquer and covered with gold powder. The missing parts were restored with gypsum and colored with acrylic color. After that, the repair materials were aged and emergency treatment was performed at the National Museum of Korea in 1981. At that time, Cemedine C or Cemedine C mixed with microballoons was used for reinforcing the cracks. Conservation treatment focused on removing the past repair materials and reinforcing the physically fragile parts by joining and restoring them based on the examination of the preservation condition. in addition, the area around the restored part was colored for future exhibition.