• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.11
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• pp.1481-1487
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• 2002

The thin SiC filament technique has been employed to identify the possibility of measuring flame temperature, and especially unstable near-extinction flame temperature in an oxidizer deficient ambience, by comparing the relative visible (non-IR) luminosities of SiC filaments with thermocouple measured temperature in co-flowing, laminar propane/air diffusion flames. The results show good agreement between the digitized relative visible luminosity profiles of the SiC filaments and temperature profiles measured using a thermocouple at temperatures above $700^{\circ}C$, although, a non-linear calibration is probably required far the whole temperature range. The highest radial peak temperature exists near to the nozzle exit. and the centerline temperatures were virtually unchanged with increasing flame height in an oxidizer deficient near-extinction flame.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.8
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• pp.1982-1988
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• 1995

Methane/Air premixed flames are studied numerically, using a detailed chemical model, to investigate the flame strech effects on the extinction in a counterflow. The finite difference method, time integration and modified Newton iteration are used, and adaptive grid technique and grid smoothing have been employed to adjust the grid system according to the spatial steepness of the solution profiles. Results show that the flame stretch, or the conventional nondimensionalized stretch having the tangential flow characteristics of the stretched flame alone cannot adequately describes the extinction phenomena. On the other hand, the local flame stretch having both the normal and tangential flow characteristics of the stretched flame can give a proper explanation to the extinction of the symmetric planar premixed flames stabilized in a counter flow. The extinction condition were found to be a constant local stretch regardless of the equivalence ratio.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.56-61
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• 1995

The behaviors of flame propagation and quenching in a pipe were investigated to make a design criteria of flame arrester. The effects of sealing condition of pipe end, pipe diameter and lengh were studied, and also the effects of thickness of ceramic honycomb monolith on the quenching ability were discussed. Experimental results showed that the flame velocity in case of closed pipe was increased about twenty times faster than that of opened and the sealing coditions of pipe end and length showed significant effects on it. The quenching ability of ceramic honycomb monolith was Increased with thickness and coincided well with Palmer's equation.

• 대한핵의학회:학술대회논문집
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• 1988.05a
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• pp.138.2-139
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• 1988

• The Journal of Internal Korean Medicine
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• v.3 no.1
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• pp.49-66
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• 1986

• Proceedings of the Korean Society of Life Science Conference
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• 2002.03a
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• pp.66-66
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• 2002

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.9-28
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• 2020

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most commonly used drugs worldwide for chronic pain, such as arthritis, and there are many different types depending on their composition and mechanism. After long-term use, various side effects can occur, such as gastrointestinal and cardiovascular complications. With a similar analgesic effect to that of traditional non-selective NSAIDs, cyclooxygenase-2-selective NSAIDs have been highly anticipated, because they could complement gastrointestinal tolerance. On the other hand, because of concerns about cardiovascular safety in 2004 and 2005, and the license withdrawals of rofecoxib and valdecoxib, the interest in the side effects of NSAIDs is increasing. Therefore, it is important to use the necessary drugs at a minimum, considering the side effects and interactions of each drug. This study examined the side effects and characteristics of each NSAID that may occur and reviewed the recent research and guidelines related to the use of non-selective NSAIDs and cyclooxygenase-2-selective NSAIDs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.7
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• pp.585-592
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• 2016

Visualization was done by using $CH^*$ chemiluminescence images and PMT measurements in order to understand the origin of fluctuating pressure and chemical luminosity at about 500 Hz frequency even in stable combustion, which was observed in recent experimental tests, and to find the physical correlation leading to Low Frequency Instability(LFI) in terms of phase angle. In stable combustion, chemical reactions are distributed along the shear layer flow showing a negative coupling(about 180 degree in phase angle) with combustion pressure. However, phase difference is shifted to a positive coupling showing less than 90 degree in unstable case. Also a periodic change in the distribution of chemical reactions is observed along with local flame extinction and the appearance of big scale vortex flow. In the transition to LFI, local flame extinction and small vortex flow start to appear in a row. As seen in the bluff body wake in reactive flow, the periodic appearance of vortex flow seems to share the same physical process of BVK(Bernard Von Karman) instability generation. Thus, the appearance of local extinction in 500 Hz fluctuations is gradually amplified to complete extinctions of about 20 Hz, and it leads into LFI.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.450-451
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• 2009

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.8.2-8.2
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• 2005