• The Journal of Korean Medicine
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• v.23 no.1
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• pp.92-99
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• 2002

Objectives : To investigate the role of Meridian flow on acupuncture effect, we observed the therapeutic effects of electroacupuncture (EA) after Meridian blocking with pressure in arthritic rats. Methods : To make reliable and local monoarthritis, $40{\;}{\mu}l$ complete Freund's adjuvant was injected into the tibio-tarsal joint. EA was applied on acupoint GB30 while 5 Pascal pressure was added to the middle of the Gall bladder Meridian around GB31 between acupoint GB30 and arthritic foci (ipsilateral meridian blocking: IB) or opposite part of IB (contralateral part blocking: CB). To observe the change of arthritis, extension and flexion pain scores and circumferential differences were evaluated once a week. Results : EA stimulation without blocking reduced arthritic pain significantly. IB abolished the acupuncture effects and there was no statistical difference with the arthritic control group, whereas the CB group still showed the therapeutic effects of acupuncture. Conclusions : This finding strongly supports that the Meridian blocking with local pressure reduced the therapeutic effect of EA.

• Journal of Power System Engineering
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• v.19 no.1
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• pp.56-63
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• 2015

In this study, the exhaust characteristics of the diesel engine for the change of the mixing ratio of biodiesel fuel were quantitatively analyzed by using the numerical analysis method. As the fuel used in the experiment, the diesel and biodiesel(waste oil, soybean oil), the mixed fuel BD2(Diesel only), BD3, BD5, BD20, BD50 and BD100 were used. The injection pressure($p_{inj}$) was set to 400bar, 600bar, 800bar, 1000bar and 1200bar as the experimental variable. Also the concept of the standard deviation, Pearson's correlation coefficient and Spearman rank-order correlation coefficient based on the statistics was introduced in order to analyze the exhaust characteristics of the quantitative NOx and Soot according to the injection pressure and the mixing ratio variation of biodiesel blending fuel. It is considered that as a result of studies, for the waste oil, NOx and Soot can be simultaneously reduced through control of the mixing ratio at the regions of $p_{inj}=400bar$ and $p_{inj}=600bar$, and the Soot can be reduced without affecting on the emission of NOx at more than $p_{inj}=800bar$. For the soybean oil, NOx and Soot can be simultaneously reduced at $p_{inj}=400bar$ and the Soot can be reduced without affecting on the emission of NOx at $p_{inj}=600bar$.

• International Journal of Fluid Machinery and Systems
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• v.7 no.3
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• pp.110-124
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• 2014

Surge phenomena in the zone of reduced speeds in a system of a nine-stage axial flow compressor coupled with ducts were studied analytically by use of a surge transient simulation code. Main results are as follows. (1) Expansion of apparently stable, non-surge working area of the pressure vs. flow field beyond the initial stage-stall line was predicted by the code in the lower speed region. The area proved analytically to be caused by significantly mismatched stage-working conditions, particularly with the front stages deep in the rotating stall branch of the characteristics, as was already known in situ and in steady-state calculations also. (2) Surge frequencies were found to increase for decreasing compressor speeds as far as the particular compressor system was concerned. (3) The tendency was found to be explained by a newly introduced volume-modified reduced surge frequency. It suggests that the surge frequency is related intimately with the process of emptying and filling of air into the delivery volume. (4) The upstream range of movement of the fluid mass having once passed through the compressor in surge was found to reduce toward the lower speeds, which could have caused additionally the increase in surge frequency. (5) The concept of the volume-modified reduced surge frequency was able to explain, though qualitatively at present, the behaviors of the area-pressure ratio parameter for the stall stagnation boundary proposed earlier by the author.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.457-464
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• 1999

The active earth pressure on the retaining wall is reduced by 3-Dimensional effects of the ground. Therefore, the test was focused on reducing the earth pressure on the retaining wall by inserting the vertical reinforcement in the backfill ground to develope the 3-Dimensional effects. Model tests in sand were peformed to measure the 3-Dimensional effects of the vertical reinforcement on the active earth pressure and its distribution and results were compared with the theories. The size of the vertical reinforcement, the geometry of the backfill space, and the wall friction of vertical reinforcement were varied. It was observed that the active earth pressure and its distribution on the underground structure were affected by the size of the vertical reforcements and wall friction.

• Journal of the Korean Ceramic Society
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• v.30 no.4
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• pp.309-315
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• 1993

Gas pressure sintering is a promising process in various densification methods of high strength Si3N4 ceramics. Environmental influences on gas pressure sintering of Si3N4 was investigated with the variationof packing powder, specimen container and N2 gas pressure. The specimens had higher density, larger weight loss and inhomogeneous color in graphite specimen container than in SN26 crucible. The variations of sintering densities in various packing powders (Si3N4, SN26, AlN, BN) were very small but SiC powder was synthesised in graphite crucible with Si3N4 packing powder, aluminium oxynitride compounds were synthesised in SN26 crucible with AlN packing power. Also N2 gas pressure over 20kg/$\textrm{cm}^2$ reduced the densification of Si3N4 in one step-gas pressure sintering. As the result of two step-gas pressure sintering at 700kg/$\textrm{cm}^2$ for 15min., relative density of 99.9% and 3-point bending strength of 1090MPa and dense microstructure of 3~4${\mu}{\textrm}{m}$ grain size were obtained.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.214-219
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• 2005

This experiment was conducted in order to identify the effect of the laryngeal mask airway and it's clinical utility on cardiovascular system, intraocular pressure and stress reaction at the time of anesthesia care. The heart rate, systolic arterial pressure, diastolic arterial pressure and intraocular pressure were significantly reduced in the experimental group to be compared with the control group. But, there were no significant differences in mean arterial pressure, central venous pressure and blood cortisol concentration between both groups. In view of the above results, it is thought that the airway management using the laryngeal mask airway will be useful to reduce the stress condition in the induction of anesthesia.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.513-519
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• 2005

The Korean Tilting Train eXpress may produced a strong micro-pressure wave in tunnel exit because of large train/tunnel area ration of conventional railways. This micro-pressure wave causes an impulsive noise which is a serious environmental noise pollution near tunnel exit. Tunnel hood can be the method of reducing the micro-pressure wave in tunnel exit. Therefore, parametric studies for tunnel hood are performed with respect to the hood length and size to investigate the effects of the tunnel hood. Also, axi-symmetric unsteady compressible flow solver was used to analyze train-tunnel relative motion. According to the result of numerical analysis, the maximum micro-pressure wave in tunnel exit is reduced by 56% throughout the hood establishment on conventional railways.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.4
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• pp.670-690
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• 2015

In this paper, numerical investigations for tank sloshing, based on commercial CFD package FLUENT, are performed to study effects of boundary layer grid, liquid viscosity and compressible air on sloshing pressure, wave height and rising time of impact pressure. Also, sloshing experiments for liquids of different viscosity are carried out to validate the numerical results. Through comparison of numerical and experimental results, a computational model including boundary layer grid can predict the sloshing pressure more accurately. Energy dissipation due to viscous friction leads to reduction of sloshing pressure and wave elevation. Sloshing pressure is also reduced because of cushion effect of compressible air. Due to high viscosity damping effect and compressible air effect, the rising time of impact pressure becomes longer. It is also found that liquid viscosity and compressible air influence distribution of dynamic pressure along the vertical tank wall.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.5
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• pp.513-522
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• 2015

This study is to confirm the effect of pre-installed pipe-roof by measuring earth pressure acting on the underpass. In recently developed trenchless methods pre-inserted steel pipes before ground excavation to form pipe-roof are connected each other with re-bars and filled with mortar. In this study, focusing on the Upgraded Pipe Roof Structure method (UPRS) and Front-Jacking, earth pressure around pipe-roof is measured after insertion of steel pipe to ensure the effect of earth pressure reduction. In case of the UPRS earth pressure is considerably reduced because of the reinforced effect of pipe-roof. In case of the Front-Jacking in which the whole underpass structure is pushed into the ground, earth pressure is not reduced as expected, because the pre-installed pipes are not needed to be reinforced.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.593-599
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• 1996

The effects of high pressure on alliinase and on flavor of garlic (Alliiium sativum L.) were investigated. After pressurized at 150 MPa, 300 MPa, and 500 MPa for 10 min, the activities of purified alliinase were reduced approximately 30%, 80%, and 100%, respectively, while the enzyme activities of pressurized garlic cloves were reduced 0%, 7%, and 100%, respectively. This indicated that the intact garlic has a protective effect against pressure-inactivation of alliinase. Alliinase was more effectively inactivated when high pressure treatment was carried out at high ($>40^{\circ}C$) or low temperature ($>10^{\circ}C$) than ambient temperature. Pressure treated garlic at 500 MPa had little pungency and sulfuryl odor compared to raw garlic indicating that high-pressure processing can be used to produce garlic without pungent flavor.