• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.3
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• pp.57-62
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• 2001

Falling film heat transfer analyses with aqueous lithium bromide solution were performed to investigate the transfer characteristics of the copper tubes. Finned (knurled) tube and a smooth tube were selected as test specimens. Averaged generation fluxes of water and the heat flux were obtained. As the film flow rate of the solution increased, the generation fluxes of water decreased for both tubes due to the fact that the heat transfer resistance increased with the film thickness. The effect of the enlarged surface area at the knurled tube was supposed to be dominant at a small flow rate. The generation fluxes of water increased with the increasing degree of tube wall superheat. Nucleate boiling is supposed to occur at a wall superheat of 20K for a smooth tube, and at 10K for a knurled tube. The increased performance of the knurled tube was supposed to mainly come from the effect of the increased heating surface area.

• The Journal of Internal Korean Medicine
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• v.11 no.1
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• pp.77-91
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• 1990

This study was carried out to investigate the effect of Jasoeumja extract on the contractile force of the isolated guinea pig trachea smooth muscle and elucidate its mechanism. The results were obtained as follows: 1. The isolated trachea smooth muscle was suspended in the Organ bath with oxygenated Kreb's Henseleit bicarbonate buffer solution at $37^{\circ}C$, and the developed tension by the drug was recorded with Isometric transducer (Nacro F-60). The resting tension was approximately 0.5g. 2. The trachea smooth muscle of the isolated guinea pig was significantly relaxed by the administration of Jasoeumja extract. 3. The contractile response of the trachea smooth muscle of the isolated guinea pig to histamine $10^{-4}M$ was significantly inhibited by Jasoeumja extract. 4. The contractile response of the trachea smooth muscle of the isolated guinea pig to acetylcholine $10^{-4}M$ was considerably inhibited by Jasoeumja extract. 5. The contractile response of the trachea smooth muscle of the isolated guinea pig to 5-hydroxytryptamine $10^{-4}M$ was considerably inhibited by Jasoeumja extract.

• The Journal of Internal Korean Medicine
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• v.11 no.2
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• pp.68-79
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• 1990

This study was carried out to investigate the effect of Heapyoyangjintang and Haepyoejintang extract on the contractile force of the isolated guinea pig trachea smooth muscle and elucidate its mechanism. The results were obtained as follows : 1. The isolated trachea smooth muscle was suspended in the organ bath with oxygenated kreb's Henseleit bicarbonate buffer solution at $37^{\circ}C$, and the developed tension by the drug was recorded with Isometric transducer(nacro F-60). The resting tension was approximately 0.5g. 2. The trachea smooth muscle of the isolated guinea pig was significantly relaxed by the administration of Haepyoyangjintang and Haepyoejintang extract. 3. The contractile response of the trachea smooth muscle of the isolated guinea pig to histamine$10^4M$ Was significantly inhibited by Heapyoyangjintang and Haepyoejintang extract. 4. The contractile response of the trachea smooth muscle of the isolated guinea pig to acetylcholine$10^4M$ was considerably inhibited by Haepyoyangjintang and Haepyoejintang extract. 5. The contractile response of the trachea smooth muscle of the isolated guinea pig to 5-hydorxytrtrypptamine $10^4M$ was considerably inhibited by Haepyoyangjintang and haepyoejintang extract.

• The Journal of Internal Korean Medicine
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• v.13 no.2
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• pp.84-94
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• 1992

This study was carried out to investigate the effect of samyootang and shinchulsan extract on the contractile force of the isolated guinea pig trachea smooth muscle and elucidate it's mechanism The isolated were obtained as follows ; 1. The isolated trachea smooth muscle was suspended in the organ bath with oxygenated kreb's Henseleit bicarbonate buffer solution at $37^{\circ}C$, and the developed tension by the drug was recored with Isometric transducer (nacro F-60) The resting tension was approximately 0.5g 2. The contractile response of the trachea smooth muscle of the isolated guinea pig to histamine $10^{-4}M$ was significantly inhibited by samyootang and shinchulsan extract. 3. The contractile response of the trachea smooth muscle of the isolated guinea pig to acetylcholine $10^{-4}M$ was considerably inhibited by samyootang and shinchulsan extract. 4. The contractile response of the trachea smooth muscle of the isolated guinea pig to histamine $10^{-4}M$ was significantly inhibited by samyootang and shinchulsan extract. 5. The contractile response of the trachea smooth muscle of the isolated guinea pig to acetylcholine $10^{-4}M$ was significantly inhibited by samyootang and shinchulsan extract.

• The Korean Journal of Pharmacology
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• v.16 no.2 s.27
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• pp.25-29
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• 1980

Etomidoline ($Nonspa^{\circledR}$), which is chemically related to tertiary amine, is new synthetic antispasmodic agent with analgesic action. Antispasmodic effect of this agent is stronger than hyoscine butylbromide ($Buscopan^{\circledR}$), quaternary amine, and the absorption from intestine is also much higher. This study was undertaken to determine the effect of etomidoline on duodenal motility and other smooth muscles of rabbit. Strips of various isolated smooth muscle, 2 cm long from adult rabbits weighting about 2 kg, were suspended in a muscle chamber containing Tyrode's solution, which was bubbled with oxygen gas, and the temperature of the solution was kept constant at $38^{\circ}C$. After being washed with fresh solution several times the strips of smooth muscle attained constant motility and tonus. Etomidoline and other drugs were added in various concentrations to the chamber. Contractility of the strips was measured by using polygraph (Grass, model 7). The results are as follows: 1) In isolated rabbit atrium etomidoline produces a slight depression of contractility and the rate is also decreased. 2) On the other hand, etomidoline relaxed isolated strips of stomach, duodenal, and detrusor of rabbit. This relaxing effect of etomidoline on isolated duodenal strip of rabbit was not blocked by ${\alpha}$-adrenergic blocking agent, phenoxybenzamine, but by ${\beta}$-adrenergic blocking agent, propranolol. 3) Etomidoline did not exert any effect on isolated aorta, gall bladder, and trigone of rabbit. From the above results, it may be concluded that the relaxing effect of etomidoline on duodenal strip is related ${\beta}$-adrenergic receptor.

• Journal of the Korean Mathematical Society
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• v.37 no.6
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• pp.1007-1019
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• 2000

In this paper, we discuss a uniqueness problem for the Cauchy problem of the Euler equation. W give a sufficient condition on the vorticity to show the uniqueness of a class of generalized solution in terms of the generalized solution in terms o the generalized Besov space. The condition allows the iterated logarithmic singularity to the vorticity of the solution. We also discuss the break down (or blow up) condition for a smooth solution to the Euler equation under the related assumption.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.23 no.4
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• pp.301-327
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• 2019

The proper orthogonal decomposition (POD) method for time-dependent problems significantly reduces the computational time as it reduces the original problem to the lower dimensional space. Even a higher degree of reduction can be reached if the solution is smooth in space and time. However, if the solution is discontinuous and the discontinuity is parameterized e.g. with time, the POD approximations are not accurate in the reduced space due to the lack of ability to represent the discontinuous solution as a finite linear combination of smooth bases. In this paper, we propose to post-process the sample solutions and re-initialize the POD approximations to deal with discontinuous solutions and provide accurate approximations while the computational time is reduced. For the post-processing, we use the Gegenbauer reconstruction method. Then we regularize the Gegenbauer reconstruction for the construction of POD bases. With the constructed POD bases, we solve the given PDE in the reduced space. For the POD approximation, we re-initialize the POD solution so that the post-processed sample solution is used as the initial condition at each sampling time. As a proof-of-concept, we solve both one-dimensional linear and nonlinear hyperbolic problems. The numerical results show that the proposed method is efficient and accurate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.105-109
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• 2002

The wet etching characteristics of magnetic materials such as NiFe and CoFe were investigated in terms of etch rate and etch profile by using variouus etching solutions (etchants). Among the various etching solutions, HNO$_3$, HCl, and H$_2$SO$_4$were selected for the etching of magnetic materials and showed distinct results. In the case of NiFe films, faster etch rate were obtained with HNO$_3$solution. When NiFe films ere etched with HCl solution, white etch residues were found on the surface of etched films. From FEAES analysis of these etch residues, they were proved to be by-product from the reaction of NiFe with Cl element. CoFe thin films showed the similar trend to the case of NiFe films. They were etched fast in HNO$_3$ solution while Chl solution represented slow etching. The etch profiles of CoFe films showed smooth etch profile but revealed the partial etching around the patterns in HNO$_3$solution of relatively high concentration. It was observed that the etched surface was clean and smooth, and that white etch residues were also remained on the etched films.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.471-478
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• 1994

Effects of histamine on the ruminal smooth muscle motility of cattle were investigated in the longitudinal and circular smooth muscle strips. In order to these experiments, specimens were obtained from 35 korean native cattles, 3-4 years old, in Kwang-ju area slaughterhouse. Smooth muscle strips of rumen were made from sample, and then measured the isometric contraction with physiograph in $37{^{\circ}C}$ organ bath. The results were as follows : 1. Histamine caused two different types of response(a contraction or a relaxation) on the smooth muscle of cattle rumen. These responses increased in dose dependant manner. 2. Pyrilamine($H_1$-receptor antagonist) completely blocked contraction in all the preparation and converted the response into relaxation. 3. Cimetidine($H_2$-receptor antagonist) completely blocked relaxation in all the preparation and converted the response into contraction. 4. The contraction induced by histamine($10^{-3}M$) was not Mocked by cholinergic, adrenergic blocker or hexamethonium. 5. The contraction induced by histamine($10^{-3}M$) was markedly inhibited in the $Ca^{2+}$ free(or EDTA 2Na) Kreb's solution and by verapamil.

• Journal of Korean Neurosurgical Society
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• v.38 no.5
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• pp.375-379
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• 2005

Objective : Papaverine has been used in treating vasospasm following subarachnoid hemorrhage[SAH]. However, its action mechanism for cerebral vascular relaxation is not clear. Potassium channels are closely related to the contraction and relaxation of cerebral smooth muscle. Therefore, to identify the role of potassium and calcium channels in papaverine-induced vascular relaxation, we examine the effect of papaverine on potassium channels in freshly isolated smooth muscle cells from rat basilar artery. Methods : The isolation of rat basilar smooth muscle cells was performed by special techniques. The whole cell currents were recorded by whole cell patch clamp technique in freshly isolated smooth muscle cells from rat basilar artery. Papaverine was added to the bath solution. Results : Papaverine of $100{\mu}M$ into bath solution increased the amplitude of the outward $K^+$ current which was completely blocked by BKCa[large conductance calcium dependent potassium channels]blocker, IBX[iberiotoxin], and calcium chealator, BAPTA[l,2-bis[o-aminophenoxy]ethane-N,N,N',N'-tetraacetic acid], in whole cell mode. Conclusion : These results strongly suggest that potassium channels may play roles in papaverine-induced vascular relaxation in rat basilar artery.