• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.7
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• pp.1058-1072
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• 1997

A head-neck complex dummy, for measuring brain pressure and reaction force in the cervical spine was developed for experimental study related in injury mechanism. Dummy comprised aluminium-casted head with water filled cavity for simulating brain and mechanical neck assembled with six motion segments. Several kinds of experiments (compression, bending, cyclic modulus, relaxation and constant velocity profile) for the developed mechanical neck showed that this neck model is biomechanically reliable compared with in-vitro test results. As an application of developed head-neck complex dummy, shock absorbing properties of protective helmet was chosen. The experiments showed that the maximum pressure increment of brain after impact was tolerable compared with the guide line for mild brain injury pressure (25psi). Constrast to this results, the reaction force in the neck was high enough to produce failure in the cervical spine.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1496-1503
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• 2005

The study on the lateral earth pressure is briskly preformed for various conditions such as type of retaining walls, ground condition, and type of supporting systems. It is not simple to determine the distribution of lateral earth pressure accurately, however, because the lateral earth pressure is affected by various factors. This study is performed to analyze the behavior of earth retaining walls for new excavation contacting with existing excavation by comparing with the site measuring values before and after new excavation. On the base of observation, the distribution of strut axial forces is similar to that of ganeral earth retaining walls, but strut axial forces is increased by removal of existing earth anchors. When new excavation is performed contacting with existing excavation, the axial force of strut is decreased because of soil exclusion in the behind walls, but that force is increased after new exeavation. The analysis result show that the installation of strut in middle part makes a effect to not only 1 adjacent strut, but 3-5 adjacent struts. Also during new excavation strut axial forces is decreased by relaxation of total earth retaining wall system.

• Membrane Journal
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• v.31 no.5
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• pp.343-350
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• 2021

In this study the suction pressure was measured with respect to operational time by submersing the multi-bore capillary membrane module in membrane bioreactor(MBR). The hexagonal shape capillary module which has the nominal pore size of 0.2 ㎛, outer diameter of 6.4 or 4.2 mm was immersed in MLSS 8,000 mg/L active sludge aqueous solution, and confirmed changes with respect to permeation flux and air flow rate. It was operated by the filtration/relaxation(FR), FR with backwashing(FR/BW), and sinusoidal flux continuous operation(SFCO) modes. The suction pressure for the SFCO and FR modes was lower at 30 and 50 L/m²·hr, respectively. In addition, the suction pressure of the module with a small outer diameter was relatively low. The suction pressure of a large outer diameter was greatly increased, but it could be reduced by more than 40% by backwashing.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.2
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• pp.408-413
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• 2007

Vascular tone plays an important role in the regulation of blood pressure. In the present study, the methanol extract of Rosae multiflora Radix (MRM) induced dose-dependent relaxation of phenylephrine-precontracted aorta, which was abolished by removal of functional endothelium. Pretreatment of the endothelium-intact aortic tissues with $N^G$-nitro-L-arginine methly ester (L-NAME) or 1H-[1,2,4]-oxadiazole-[4,3-${\alpha}$]-quinoxalin-1-one (ODQ) inhibited the relaxation induced by MRM, respectively. But, the relaxation effect of MRM was not blocked by indomethacine, glibenclamide, tetraethylammonium (TEA), verapamil, diltiazem, atropine, and propranolol, respectively. Moreover, incubation of endothelium-intact aortic rings with MRM increased the production of cGMP. Taken together, the present results suggest that MRM relaxes vascular smooth muscle via endothelium-dependent nitric oxide/cGMP signaling. These results would be useful for further study to MRM on animal models with cardiovascular diseases.

• Journal of Welding and Joining
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• v.11 no.4
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• pp.103-111
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• 1993

Recently, several high-tensile steels(e.g. 80kg and above, $2^{1/4}Cr$-1Mo)having good quality to high temperature and pressure-resistance are widely used to construct petroleum-plant and pressure vessel of heat or nuclear-power plant. However, in the steels, reheating crack at grain boundaries of the heat affected zone(HAZ) occures during post welding heat treatment(PWHT)to remove welding residual stress. In order to study theoretically the characteristics of reheating crack created by PWHT, the computer program of three-dimensional thermal-elasto-plasto-creep analysis based on finite element method are developed, and then the mechanical behavior(history of creep strain accumulation and stress relaxation, etc)of welded join in thick plate during PWTH is clarified by the numerical results.

• Tribology and Lubricants
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• v.21 no.6
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• pp.272-277
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• 2005

Continuously variable transmission (CVT) of toroidal type has a elliptical shape of contact zone under the elastohydrodynamic lubrication (EHL) condition, where the power is transmitted only by shearing the lubricant. Due to the small contact area of elliptical shape, the traction of the shear behaviors of lubricant over the contact zone is under extremely high contact pressure over 1.0GPa. During the power transmission by shearing the fluid, many kinds of mechanical movements occur such as squeezing, sliding, rolling and spin. Among the movements, the spin effect that is the most undesirable contact behavior in transmitting the power frequently makes significant abnormal wear damage. In this work, the analysis of elliptical contact of EHL with spin effect is performed, which will give very useful information to understand the traction behaviors in toroidal type of CVT system.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.33-36
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• 2009

In this paper, evaluation of physical properties was made for dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of fatty acid monomolecular Arachidic Acid, Stearic Acid using compressing velocity. LB(Langmuir-Blodgett) thin films were manufacture by detecting deposition for the accumulation and the current was measured after the electric bias was applied across the manufactured MIM device. The physicochemical properties of the fatty acid monomolecular Arachidic Acid, Stearic Acid films surface structure has been studied by AFM. We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is gas state, liquid state, solid state. Formation that prevent when gas phase state and liquid phase state measure but could know organic matter that molecules form equal and stable film when molecules were not distributed evenly, and accumulated in solid state only.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.2
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• pp.35-43
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• 1984

The purpose of this paper is to develop a mathematical model which can be used to compute the position of the free surface due to water level fluctuations in the canal and the transient pressure distributions along the canal lining. The diagnostic equation has been solved by the point successive over-relaxation method, and the linearized prognostic equation has been solved by the implicit Lax-Wendroff scheme. Four different cases in the simulation conditions are presented for both permeable and impermeable canal lining to predict the transient seepage surface development.

• Korean Journal of Pharmacognosy
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• v.16 no.2
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• pp.65-72
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• 1985

These studies were conducted to investigate the effect of 'Inchungbaek' water extract on analgesic and sedative actions, the relaxing action of isolated ileums, vasodilating action and blood pressure. The results of these studies were summarized as follows: Analgesic and sedative actions of 'Inchungbaek' were recognized in mice and rats. The relaxing action of isolated ileums were seen in mice and rabbits, antagonist action was seen acetylcholine and $BaCl_2-induced$ contraction of isolated ileums, and then recognized direct action in the ileum smooth muscle. Hypotensive and vasodilating actions due to vascular smooth muscle relaxation were noted in rabbits and cats.

• Textile Coloration and Finishing
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• v.9 no.2
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• pp.10-16
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• 1997

Merino wool top and fabric have been treated with steams such as superheated steam or high pressure steam. Moisture regain, water absorbency, water penetration, zeta potential, ESCA, SEM, and dyeing behavior were studied. Negative electric potential on the surface of wool fibers by steam treatment became higher than untreated. From the results of ESCA measurement, intensity of $O_{1s}$ was increased by steam treatment. Rate of dyeing and saturation dye exhaustion of wools increased by steam treatment, especially high pressure steam treatment. Moisture regain, water absorbency, water penetration, and surface appearances by SEM photographs of the steam-treated wools didn't change. There is no relationship between dyeing of the steam-treated wool and wettability to water. Therefore It seems likely that relaxation of adhesive filler in interscale of wool by steam treatment accelerate dye penetration into the fiber.