• The KSFM Journal of Fluid Machinery
• /
• v.6 no.1 s.18
• /
• pp.44-50
• /
• 2003

Flow through a turbine flow meter is simulated by solving the incompressible Navier-Stokes equations. The solution method is based on the pseudo-compressibility approach and uses an implicit-upwind differencing scheme together with the Gauss-Seidel line relaxation method. The equations are solved steadily in rotating reference frames, and the centrifugal force and the Coriolis force are added to the equation of motion. The standard $k-{\epsilon}$model is employed to evaluate turbulent viscosity. Computational results yield quantitative as well as qualitative information on the design of turbine flow meters by showing the distributions of pressure and velocity around the turbine blades.

• Journal of Wetlands Research
• /
• v.2 no.1
• /
• pp.11-17
• /
• 2000

The natural ecology of our coastal zone has been well preserved because of the designation of Han-Ryea national sea park. However, recently, it is being threatened by the frequent request of district regulation of national park and relaxation of green belt, etc. And also, with the reclamation of the foreshore by the development of industrial complex and tourism resource cultivation on a large scale, development pressure for natural coast is increasing. For that reason, preservation of the ecology, organized management and investigation is needed for the islands which scenery is beautiful and rare animals and plants inhabit. And also, it is worried that major habitats of migrants are diminishing because of the district regulation of national park, relaxation of green belt zone and construction of coastal streets. Therefore. on the basis of the through environmental impact assessment, only the business which are aimed at the preservation and restoration of the natural coast should be admitted and the act of eroding must be restricted.

• The Korean Journal of Ceramics
• /
• v.4 no.2
• /
• pp.128-135
• /
• 1998

The paper gives a brief introduction to protonic defects and their chemistry, thermodynamics and transport in oxides. The temperature dependence of the equilibrium concentration of protons is illustrated and compared for different acceptor-doped oxides. The difficulties of saturating as well as emptying the oxides of protons are discussed. In order to illustrate the possibility of lattice relaxation of defects, a conceptual study is made of a case where the enthalpy of dissolution of protons(water) at the cost of oxygen vacancies is assumed dependent on the concentration of vacancies. It is shown how this changes the behavior of hydration curves vs temperature and water vapour pressure. finally, a discussion is given on the water uptake in heavily oxygen deficient oxides; how water uptake may affect order-disorder in the oxygen sublattice and eventually lead to defective, disordered or ordered oxyhydroxides or hydroxides of potential interest as intermediate temperature proton conductions.

• Journal of the Korean Society of Safety
• /
• v.22 no.2 s.80
• /
• pp.22-27
• /
• 2007

To assess a creep life of elevated temperature plant components, inspections and analysis are usually focused on the critical locations. In this study, stress analysis of a weld region in branch part of Y-piece was conducted by using a three-dimensional finite element analysis. The stresses at the inner and outer surface in the weld part were estimated by using elastic and elastic-creep analysis. For the elastic-creep analysis two kinds of elastic-creep analysis was conducted. The one was assumed that base and weld material properties were same and the other was that material properties were different between base and weld metal. The material properties of base and weld metal were used from reference data. The results showed the stress relaxation level and its location. The result stresses are also compared with elastic stresses.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.2
• /
• pp.130-138
• /
• 2006

We have investigated pattern scaling down of silicon stamps through the oxidation technique, During oxidizing the silicon stamps, silicon dioxide that has 300 nm and 500 nm thickness was grown, and critical deformations were not observed in the patterns. There was positive effect to reduce size of patterns because vertical and horizontal patterns have different orientation. We achieved pattern reduction rate of $26\%$. In addition, the formation of polymer patterns had been investigated with varied temperature and pressure conditions to improve the filling characteristics of polymers during nanoimprint lithography when pattern sizes were few micrometers. In these varied conditions, polymers had been affected by free space compensation and elastic stress relaxation for filling the cavities. Based on the results, defect control which is an important issue in the nanoimprint lithography were facilitated.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1999.04a
• /
• pp.268-275
• /
• 1999

The purpose of this study is to propose the method of determining the initial pneumatic membrane structures surface and stresses and displacements. Tension structure such as pneumatic membrane structures is stabilized by their initial prestress and air pressure. The process to find initial structural overall shape of tension structures produced by initial prestress called shape finding. One of the most important factor for the design of membrane structures is to search initial smooth surface, because unlike steel or concrete building elements which resist loads in bending, all tension structure forces are carried within the surface by membrane stress. The result for initial surface of pneumatic membrane element and maximum displacement in large deformation in analysis is compared with well-known nonlinear numerical method such as Newton-raphson method and dynamic relaxation method

• Korean Journal of Pharmacognosy
• /
• v.15 no.4
• /
• pp.188-193
• /
• 1984

It was previously indicated that 'Samulanshintang' had been examined for effects of the anticonvulsive, antipyretic, analgesic, sedative and antispasmodic actions. In order to investigate the effect on the cardiovascular system and anemic rabbits induced by phenlhydrazine HCl, pharmacological studies have been carried out with extract. The results of this investigation were summarized as follows: The relaxation of bronchial smooth muscle and antihistamine action were recognized. Antihypertensive and vasodilating actions due to vascular smooth muscle relaxation were noted in frogs and rabbits. 'Samulanshintang' lowered the rate of anemia induced by phenylhydrazine and rapidly recovered from the anemia state.

• Korean Journal of Pharmacognosy
• /
• v.18 no.4
• /
• pp.241-248
• /
• 1987

Woohwangchungsim-Won has been widely used for the treatment of appoplexy, hypertension, arteriosclerosis, insomnia and cerebrovascular accident, etc in oriental hospital and pharmacy. In order to investigate the efficacy of Woohwangchungsim-Won, the water extract of it were bioassayed for isolated ileum, blood vessels, blood pressure, heart and diuresis. The results of this studies were as follows; Spontaneous motilities of isolated ileum of mice were strongly suppressed, and contraction of isolated ileum of mice and guinea-pigs induced by acetylcholine chloride, barium chloride and histamine were inhibited. Vaso-dilating action due to vascular smooth muscle relaxation in frogs and rabbits, and hypotensive action in anesthetized rabbits were noted. Negative inotropic action on the isolated frog heart and diuretic effect in rabbits were shown.

• Geomechanics and Engineering
• /
• v.14 no.4
• /
• pp.325-336
• /
• 2018

Deformation of rock masses is not only related to rock itself, but also related to discontinuities, the latter maybe greater. Study on crack propagation at discontinuities is important to reveal the damage law of rock masses. DDARF is a discontinuous deformation analysis method for rock failure and some modified algorithms are proposed in this study. Firstly, coupled modeling methods of AutoCAD-DDARF and ANSYS-DDARF are introduced, which could improve the modeling efficiency of DDARF compared to its original program. Secondly, a convergence criterion for automatically judging the computation equilibrium is established, it could overcome subjective drawbacks of ending one calculation by time steps. Lastly but not the least, relationship between the super relaxation factor and the calculation convergence is analyzed, and reasonable value range of the super relaxation factor is obtained. Based on these above modified programs, influences on crack propagation of joint angle, joint parameters and geo-stresses' side pressure are studied.

• Journal of the Korean Chemical Society
• /
• v.20 no.6
• /
• pp.448-452
• /
• 1976

A simplified statistical mechanical method was developed for the calculation of the dehydration fraction, activation free energy of dehydration, and the relaxation times of hydrated ions. The model used includes the equilibrium constant between hydrated and dehydrated water, a water-ion interaction potential energy term, and a mixing factor for the species present. The agreement between theory and experiment is good. The pressure dependence of ion dehydration is also discussed.