• Journal of the Korean Ceramic Society
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• v.25 no.1
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• pp.78-82
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• 1988

Good quality LiNbO3 single crystals which can be applied to SAW devices, were grown by Czochralski method. It was observed that the gas-bubbles were concentrated in ring shape at the outer part of grown crystals, and this anomaly was illustrated by modeling the mechanism of gas-bubble entrapment according to the melt flow pattern in the crucible. And this mechanism was also encertained by observation of solid-liquid interface shape of grown crystals. The optimal condition for good quality crystals was known that the solid-liquid interface shape was slightly concave.

• Transactions of Materials Processing
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• v.5 no.2
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• pp.156-164
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• 1996

To investigate the behavior of plastic deformation in axisymmetric extrusion through square dies, experimental works with the plasticine as a model material are carried out at the room temperature. Some mechanical properties of the model material are determined by compression and ring compression tests. Visioplasticity method using expermental grid distortion in extrusion is introduced to analyze the plastic flow strain rate and strain distribution. In spite of severe deformation during the extrusion through square die the visioplasticity method shows good results for the distribution of effective strain rate and effective strain.

• Journal of the Korea Furniture Society
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• v.29 no.1
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• pp.1-7
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• 2018

A study was carried out to observe the 1% aqueous safranine solution flow speed in longitudinal and radial directions of softwood Metasequoia glyptostroboides, diffuse-porous wood Anthocephalus cadamba and ring-porouswood Fraxinus rhynchophylla. In radial direction, ray cells and in longitudinal direction, tracheids, vessel and wood fiber were considered for the measurement of liquid penetration speed at less than 12% moisture contents (MC). The length, lumen diameter, pit diameter, end wall pit diameter and the numbers of end wall pits determined for the flow rate. The liquid flow in the those cells was captured via video and the capillary flow rate in the ones were measured. Vessel in hardwood species and tracheids in softwood was found to facilitate prime role in longitudinal penetration. Anatomical features like the length and diameter, end-wall pit numbers of ray parenchyma were found also responsible fluid flow differences. On the other hand, vessel and fiber structure affected the longitudinal flow of liquids. Therefore, the average liquid penetration depth in longitudinal tracheids of Metasequoia glyptostroboides was found the highest among all cells considered in Anthocephalus cadamba and Fraxinus rhynchophylla In radial direction, ray parenchyma of Metasequoia glyptostroboides was found the highest depth and the one of Fraxinus rhynchophylla was the lowest. The solution was penetrated lowest depth in the wood fiber of Fraxinus rhynchophylla. The large vessel of Fraxinus rhynchophylla was found the lowest depth among the vessels. The solutin was penetrated to the wood fiber of Anthocephalus cadamba higher than the one of Fraxinus rhynchophylla.

• Journal of the Korea Furniture Society
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• v.28 no.1
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• pp.88-93
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• 2017

A study was carried out to observe the 1% aqueous safranine solution flow speed in longitudinal and radial directions of softwood Larix kaempferi (Lamb.)Carriere, diffuse-porous wood Betula davurica Pall.. and ring-porouswood Castanea crenata S.etZ. In radial direction, ray cells and in longitudinal direction, tracheids, vessel and wood fiber were considered for the measurement of liquid penetration speed at less than 12% moisture contents (MC). The length, lumen diameter, pit diameter, end wall pit diameter and the numbers of end wall pits determined for the flow rate. The liquid flow in the those cells was captured via video and the capillary flow rate in the ones were measured. Vessel in hardwood species and tracheids in softwood was found to facilitate prime role in longitudinal penetration. Anatomical features like the length and diameter, end-wall pit numbers of ray parenchyma were found also responsible fluid flow differences. On the other hand, vessel and fiber structure affected the longitudinal flow of liquids. Therefore, the average liquid penetration depth in longitudinal tracheids of Larix kaempferi was found the highest among all cells considered in Betula davurica and Castanea crenata, In radial direction, ray parenchyma of Larix kaempferi was found the highest depth and the one of Betula davurica was the lowest. The solution was penetrated lowest depth in the wood fiber of Castanea crenata. The large vessel of Castanea crenata was found the lowest depth among the vessels. The solutin was penetrated to the wood fiber of Betula davurica higher than the one of Castanea crenata.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.2023-2026
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• 2008

Cooling technologies using natural and forced convection are limited and operated in very low efficiency. The corona discharge is utilized as the driving mechanism for an ionic pump, which allows for air flow control and generation with low noise and no moving parts. These ideal characteristics of ionic pump give rise to variety applications. However, all of these applications would benefit from maximizing the flow velocities and efficiencies of the pumps. In this study a needle-mesh type ionic pump, with a ring type third electrode installed just near the needle point, has been investigated by focusing on elevating the ionic wind velocity and efficiency. As a result, the enhanced ionic wind velocity and increased power yield can be obtained with the proposed ionic pump with the third electrode.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.266-268
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• 2011

We present a mathematical model of left heart governed by the partial differential equations. This heart is coupled with a lumped model of the whole circulatory system governed by the ordinary differential equations. The immersed boundary method is used to investigate the intracardiac blood flow and the cardiac valve motions of the normal circulation in humans. We investigate the intraventricular velocity field and the velocity curves over the mitral ring and across outflow tract. The pressure and flow are also measured in the left and right heart and the systemic and pulmonary arteries. The simulation results are comparable to the existing measurements.

• Journal of Korean Medical classics
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• v.17 no.4
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• pp.37-56
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• 2004

In the Circular flow of Meridians(經脈), the circulation of Nutrient Gi(營氣) is that the essence Gi(精氣) of food starts from Middle Cho(中焦), via heart and lung into the ring-type round of 12 Meridians(十二經脈) in turn of hand Meridians(水經) and foot Meridians(足經), Yang Meridians(陽經) and Eum Meridians(陰經). The circulation of Defensive Gi(衛氣) is that if going out from Eum part(陰分) into Yang part(陽分), is rounding on the Yang Meridians, if going out from Yang part into Eum part, is rounding on the five Jang(五臟) in order of Kidney(腎)-Heart(心)-Lung(肺)-Liver(肝)-Spleen(脾). Because the process of accumulating the essence Gi has a property of One-way flow, it flows from terminal to the direction of body trunk, has no distinct channel with its immaterial nature. and is concentrated on the lower part to that the five Jang belong.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.5
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• pp.1011-1018
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• 1992

A series of experiment has been performed on the spray characteristics in a cylindrical confined space with the injection pressure taken as a parameter. By using a single-hole patternator and the Malvern particle sizer, the spray mass flux, drop size and volume concentration distributions along the radial and axial directions were obtained ; the line-of- sight data by Malvern particle sizer have been converted to the ring-of-sight data by using the tomographical transformation techniqe. The experimental results show that, due to the restriction on the ambient gas entrainment by the wall boundary, the effective spray angle is increasing. The spray drops were measured to be smaller in the confined space because of a large number of floating small drops by recirculation of the gas phase and the breakup of large drops by the wall collision. Also the details on the flow behavior of the confined spray are discussed.

• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.75-79
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• 1991

A series of compounds, N-(2-substituted-1-carboxy)vinylazetidinones were successfully synthesized in order to test the hypothesis that biological activities of ${\beta}$-lactam antibiotics could be attributed to the smooth flow of electrons after a nucleophilic attack at the carbonyl carbon in the ${\beta}$-lactam ring. After introduction of aminothiazolylacetamido group at 3-position of the azetidinones, their biological activities were evaluated. Their low activities led to the conclusion that the smooth electron flow in ${\beta}$-lactams in not the sufficient source for the biological activities.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.815-829
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• 2008

Debris flows are a natural hazard which looks like a combination of flood, land and rock slide. Large rainfall in July 2006 produced several large scale debris flows and many small debris flows that resulted in loss of life and considerable property and railway damage, as was widely reported in the national media. The hazard "debris flow" is still insufficiently researched. Furthermore debris flows are very hard to predict. Flexible Ring net barriers are multi-functional mitigation devices commonly applied to rock fall or floating wood protection in floods, snow avalanches and also mud flows or granular debris flows, if properly dimensioned for the process or processes for which they are intended. Overtopping of the barriers by debris flows and sediment transport is possible, supporting the design concept that a series of barriers may be used to stop volumes of debris larger than are possible using only one barrier. The future for these barrier concepts looks promising because these barriers represent the state of art for such applications and are superior to many other available options.