• Korean Journal of Materials Research
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• v.2 no.6
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• pp.461-467
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• 1992

A fabrication process for SiC whisker preform reinforced AC4A Al composites is being developed. The Al alloy used as the matrix in this study is AC4A. SiC whisker preform made by Tokai Carbon Co. Ltd. Shizuoka, Japan were used. These consisted of $\beta$-type single crystals 0.1 ~ 10${\mu}$m in diameter and 20~10${\mu}$m in length. The most adequate fabrication condition was that whisker preform was preheated up to 750~80$0^{\circ}C$, set into a mould preheated to ~40$0^{\circ}C$, molten Al alloy heated to ~80$0^{\circ}C$ and applied pressure 75MPa. And Si$C_w$reinforced AC4A composite was advanced above twice than AC4AI/M. Also it was not large effect by pressure at Si$C_w$ 20v/o.

• Journal of Acupuncture Research
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• v.21 no.5
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• pp.137-147
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• 2004

Objective : The aim of the study was to compare the therapeutic effect of the superficial and in-depth insertion of acupuncture needles in the treatment of patients with ankle sprain. Design : A prospective randomized single-blind study of superficial and deep acupuncture was conducted. Setting : The study was conducted in the Kang-nam Oriental Hosp. of Dong-Guk University. Patients: The study comprised 14 patients with ankle sprain who were divided into two groups (A and B). Intervention : In group A, the needle was introduced in the skin at a depth of 2 mm, whereas in group B the needle was placed deeply into muscular tissue or the articular capsule at a depth more than 1.5 Cm The treatment was planned for a duration of 1 week, 3 times. Outcome Measures : The intensity of pain was evaluated with the Ankle grade pain chart(AGPC) before and after treatment and at the 1-week follow-up examination. The AGPC includes Swelling, Tenderness, Exudation, Bruise, Medial/Lateral. stability test, Anterior drawer test, Squeeze test, Bearing weight, Pressure Algometer, Walking state and VAS. Results : Although at the end of the treatment there was no evidence of significant statistical differences between the two different groups, Pain reduction(VAS) was greater in the group treated with deep acupuncture. A statistical difference existed between the two groups at the 1 week follow up, with a better result in the deeply stimulated group in VAS. Conclusion : Clinical results show that deep stimulation has a better analgesic effect when compared with superficial stimulation in pain reduction(VAS, Visual analogic scale).

• Journal of Information Display
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• v.1 no.1
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• pp.59-62
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• 2000

The first 9-inch carbon nanotube based color field emission displays (FEDs) are integrated using a paste squeeze technique. The panel is composed of 576 x 242 lines with implementation of low voltage phosphors. The uniform and moving images are achieved only at $2V/{\mu}m$, This demonstrates a turning point of nanotube for large area and full color applications.

• Composites Research
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• v.23 no.2
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• pp.10-16
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• 2010

$Al_2O_3$ fiber and SiC particle hybrid metal matrix composites (MMCs) were manufactured by squeeze casting method investigated for their tribological properties. The pin specimens had different ratios of fiber to particle content but their total weight fraction was constant at 20 wt. %. Tribological tests were performed with a pin-on-disk friction and wear tester. The investigation of the dry tribological characteristics of hybrid MMCs were carried out at room temperature and elevated temperature of$100^{\circ}C$ and$150^{\circ}C$. The morphologies of worn surfaces were examined by scanning electron microscope (SEM) to observe tribological characteristics and investigate wear behavior. The results revealed that the wear resistance improved with the content of SiCp increased of the planar random (PR) MMCs at room temperature. At the elevated temperature, it revealed that the wear resistance of normal (N) MMCs was superior to that of the PR-MMCs due to PR-fibers were easily pulled out holistically from the worn surface. Meanwhile, the coefficient of friction decreased with the temperature increasing.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.89-92
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• 2011

Purpose: Electrical burn of scalp is uncommon. Much more, chronically exposed dura in unstable burn scar is quite exceptional. Hence, we report a case of chronically exposed dura following electrical burn. Methods: A 63-year-old man presented with an about 40 years history of an ulcerative lesion arising from electrical burn scar with 'squeeze like sensation' around wound. Wound was about $6{\times}8$ cm. Area in the center was $3{\times}3$ cm nonviable dura without sequestrum. Tangential excision with an intraoperative neurosurgical consultation and transposition flap under general anesthesia was done. Intraoperative biopsy was done. The wound was diagnosed as chronic osteomyelitis, not Marjolin ulcer. Flap was taken successfully. But after 5 days, infectious discharge had been appeared during 2 weeks, despite irrigation and drainage. As flap was re-evaluated, we could see remnant necrotic dura. After that, latissimus dorsi muscle free flap with meshed split thickness skin graft was transferred without excision of necrotic dura. Results: Flap was taken successfully. Follow-up at 10 weeks has been uneventful, with good and stable coverage of the wound. Conclusion: It is true that complete excision of devitalized tissue with sagittal sinus obliteration is prerequisite to flap taken. But necrotic dura was tangentially excised instead of total dura excision, because, posterior two-thirds of the sagittal sinus was involved underneath. Muscle is rich in blood vessels and decrease the recipient-site bacterial count effectively. In this case, muscle flap with skin graft without total dura excision is an alternative treatment.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.4
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• pp.89-95
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• 2005

Thrust cut off(TCO) system is installed at the port of a rocket motor case forward dome. The snap ring and the closure are escaped sequentially by pulling out a wedge under internal pressure. The hydraulic structural tests of TCO and numerical simulations were performed, and both results were compared to understand the deformation behavior of TCO. By increasing splines symmetrically, the sealing capacity of TCO can be improved significantly. The escape pressure of TCO increases according to the increase of friction coefficient and there is a critical friction coefficient beyond which the snap ring can not be nearly escaped even after forced escape of wedge. Under low friction coefficient the snap ring is contracted to radial direction and easily escaped. But, under high friction coefficient, the snap ring can not be escaped from the port even after severe plastic deformation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.255-255
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• 2017

Sesame has been consumed for centuries as flavoring ingredient in eastern Asian countries, especially Korea. Sesame seeds have been used as health food for traditional medicine to prevent disease in Asian countries for several thousand years. Sesame seed has higher oil content (around 50%) than most of the known oilseeds. Sesame oil is rich in monounsaturated and polyunsaturated fatty acids. Extraction of sesame has developed significantly over the years. The mechanical method was an early means of separation which was physical pressure to squeeze the oil out. Nowadays, solvent extraction becomes the commonly used commercial technique to recover oil from oilseeds. In this study, we investigated extraction efficiency and quality of oil affected by cultivars and extraction methods of sesame seed. Different variables were investigated; roasting temperature ($170{\sim}220^{\circ}C$), extraction methods (solvent and physical pressure), forced ventilation system and cultivars. The Contents of B(a)P in sesame oil after roasting at $170{\sim}220^{\circ}C$ were 0.30~2.53 ppm. When we introduced forced ventilation system during roasting, B(a)P Contents were decreased up to 36%. The Oil extraction efficiency on sesame seed was statistically depending on the cultivars and extraction methods. The oil extraction yields of solvent and physical pressure extraction were 56.3% and 44.6%, respectively. Many of sesame cultivars and genetic resources are linolenic acid content of less than 0.5%. The results supported that we have developed a safe and high quality sesame oil processing methods for small and medium-sized companies.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.3
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• pp.209-217
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• 2013

This paper presents an optimal design of a magnetorheological(MR) fluid-based mount(MR mount) that can be used for to vibration control in diesel engines of ships. In this work, a mount that uses mixed-modes(squeeze mode, flow mode, and shear mode) is proposed and designed. To determine the actuating damping force of the MR mount required for efficient vibration control, the excitation force from a diesel engine is analyzed. In this analysis, a model of a V-type engine is considered. The relationship between the velocity and pressure of gas in terms of the torque acting on the piston is derived. Subsequently, by integrating the field-dependent rheological properties of commercially available MR fluid with the excitation force, the appropriate size of the MR mount is designed. In addition, to achieve the maximum actuating force under geometric constraints, design optimization is undertaken using the ANSYS parametric design language software. Through magnetic density analysis, optimal design parameters such as the bottom gap and radius of coil are determined.

• Journal of IKEEE
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• v.19 no.1
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• pp.101-109
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• 2015

As the number of smartphone users grows, number of applications and the expected overall functionality in a smartphone grow simultaneously. With ever-so increasing expectations comes intense competition to squeeze in myriads of functions in a limited space that is only getting 'slimmer' by the year. In order to achieve this, companies often decrease the size of components in smartphones - battery connectors in particular. While they may fit, smaller battery connectors have their disadvantages due to the heat generated by the high current flow in the circuits. In collaborating with Korea's leading battery connector manufacturers, this research presents current issues and design concepts that should be considered when engineers design power connectors based on their electrical and thermal analysis.

• Journal of Korea Foundry Society
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• v.23 no.4
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• pp.195-203
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• 2003

Hyper-eutectic Al-Si alloy is used much to automatic parts and material for the electronic parts because of the low coefficient of thermal expansion, superior thermal stability and superior wear resistance. In this work, A390 alloy specimens were fabricated for control of the Si particle size by various processes, such as spray-casting, permanent mold-casting and squeeze-casting. To minimize the effect of microporosity of the specimens, hot extrusion was carried out under equal condition. Each specimens were evaluated tensile properties at room temperature and thermal expansion properties in the range from room temperature to 400$^{\circ}C$. Ultimate tensile strength and elongation of the spray-cast and extruded specimens which have fine and well distributed Si particles were improved greatly compare to the permanent mold-cast and extruded ones. Specimens which have finer Si particles showed higher ultimate tensile strength and elongation than those having large Si particle size, and coefficient of thermal expansion of the specimens increased linearly with Si particle size. In case of the repeated high temperature exposures, thermal expansion properties of the spray-cast and extruded specimens were found to be more stable than those of the others due to the effect of fine and well distributed Si particles.