• Nuclear Engineering and Technology
• /
• v.56 no.1
• /
• pp.78-91
• /
• 2024

Double steel plate concrete composite shear wall (SCSW) has been widely utilized in nuclear power plants and high-rise structures, and its shear connectors have a substantial impact on the seismic performance of SCSW. Therefore, in this study, the mechanical properties of SCSW with angle stiffening ribs as shear connections were parametrically examined for the reactor containment structure of nuclear power plants. The axial compression ratio of the SCSW, the spacing of the angle stiffening rib arrangement and the thickness of the angle stiffening rib steel plate were selected as the study parameters. Four finite element models were constructed by using the finite element program named ABAQUS to verify the experimental results of our team, and 13 finite element models were established to investigate the selected three parameters. Thus, the shear capacity, deformation capacity, ductility and energy dissipation capacity of SCSW were determined. The research results show that: compared with studs, using stiffened ribs as shear connectors can significantly enhance the mechanical properties of SCSW; When the axial compression ratio is 0.3-0.4, the seismic performance of SCSW can be maximized; with the lowering of stiffener gap, the shear bearing capacity is greatly enhanced, and when the gap is lowered to a specific distance, the shear bearing capacity has no major affect; in addition, increasing the thickness of stiffeners can significantly increase the shear capacity, ductility and energy dissipation capacity of SCSW. With the rise in the thickness of angle stiffening ribs, the improvement rate of each mechanical property index slows down. Finally, the shear bearing capacity calculation formula of SCSW with angle stiffening ribs as shear connectors is derived. The average error between the theoretical calculation formula and the finite element calculation results is 8% demonstrating that the theoretical formula is reliable. This study can provide reference for the design of SCSW.

• The Korean Journal of Physiology and Pharmacology
• /
• v.5 no.1
• /
• pp.1-8
• /
• 2001

Hyperpolarization of arterial smooth muscle by acetylcholine is considered to be produced by the release of an unidentified chemical substance, an endothelium-derived hyperpolarizing factor (EDHF). Several chemicals have been proposed as the candidate for EDHF. However, none of them fulfil completely the nature and property of EDHF. Ultrastructural observation with electron microscope reveals that in some arteries, gap junctions are formed between endothelial and smooth muscle cells. In small arterioles, injection of gap junction permeable dyes into an endothelial cell results in a distribution of the dye to surrounding cells including smooth muscle cells. These observations allow the speculation that myoendothelial gap junctions may have a functional significance. Simultaneous measurement of the electrical responses in both endothelial and smooth muscle cells using the double patch clamp method demonstrates that these two cell types are indeed electrically coupled, indicating that they behave as a functional syncytium. The EDHF-induced hyperpolarization is produced by an activation of $Ca^{2+}-sensitive\;K^+-channels$ that are inhibited by charybdotoxin and apamin. Agonists that release EDHF increase $[Ca^{2+}]_i$ in endothelial cells but not in smooth muscle cells. Inhibition of gap junctions with chemical agents abolishes the agonist-induced hyperpolarization in smooth muscle cells but not in endothelial cells. All these observations can be explained if EDHF is an electrotonic signal propagating from endothelium to smooth muscle cells through gap junctions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.5
• /
• pp.87-93
• /
• 2005

In order to develope high concentration$\cdot$yield ozonizer, superposed discharge type ozonizer using overlap of silent discharge and internal electrode of mesh type has been designed and manufactured. It consists of three electrodes(central electrode, internal electrode and external electrode) and double gaps(gap between central electrode and internal electrode, gap between internal electrode and external electrode). Therefore, ozone is generated by overlapping silent discharges generated between the gaps respectively for which the AC high voltages applied to the internal electrode and the external electrode has a $180{[^\circ]}$ phase difference and for which the central electrode is a ground Ozone generation characteristics proportional to mesh of internal electrode by increasing of discharge electrode and controlling of discharge power density. As a result, the in maximum ozone concentration, generation, and yield can be obtained 17,720[ppm], 5.4[g/h], and 205[g/kwh] respectively.

• Journal of Korean Foot and Ankle Society
• /
• v.4 no.2
• /
• pp.87-92
• /
• 2000

The tendinous ends of neglected achilles tendon rupture tend to retract and separate with atrophy due to gastrosoleus muscle contracture, leaving a wide gap occupied with fibroadipose scar tissue. It is almost impossible to perform simple end-to-end anastomosis after the intervening scar tissue being excised. Therefore many surgical procedures have been proposed to reconstruct the large gap. We treated three such cases by V-Y advancement flap and double Krackow suture technique, and their postoperative strength of triceps surae were evaluated with Cybex isokinetic strength testing. All patients returned to preinjury activities with satisfaction, but the ankle plantar flexor power showed about 20-30% deficit.

• Journal of KSNVE
• /
• v.11 no.2
• /
• pp.307-314
• /
• 2001

This study aims to provide fundamental data for enhancing the sound insulation performance of windows. For this study, windows composed of various types and thicknesses, were classified into five categories； fixed, single, double, triple and airtight, and then tested. In order to analyze their sound insulation characteristics and performances. test results were rated using methods such as D, STC, Ts and arithmetical mean. It was found that the sound insulation performance of windows is affected due to their type rather than the thickness of the glass. It was also found that when gap between the inner and outer frames was filled with caulking material, the sound transmission loss at high frequency bands was greatly improved. Therefore, the sound insulation performance of windows would be enhanced by minimizing the gap between frames.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.4
• /
• pp.773-776
• /
• 2007

A microstructure array has been proposed for micro plasma generation using electroplating and double exposed process. A stable atmospheric plasma has been generated at a low voltage by utilizing the micro electrode gap. Self-aligned microstructure can provide uniform electrode overlap with precisely controlled gap between the electrodes. The proposed structure allows for triode operation, which can expand the generated plasma over a large area by applying a lateral electric field. Electrical characteristics of the micro triode confirm the large numbers of the plasma ions are drifted to the secondary cathode by the lateral electrical field.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.794-799
• /
• 2005

In this paper, the inductive power collector using electromagnetic induction for the PRT(Personal Rapid Transit) system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The proposed the inductive power collector is used for the PRT system, which has a large air-gap and demands a large electrical power capability. But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding. which was divided in half to increase both output current and output voltage was suggested. Also, model of power collector and parallel winding structure are presented, in addition, the performance of inductive power collector to alignment condition between the primary power line and the inductive power transformer was verified by computer simulation of 2kW model.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.347-348
• /
• 2008

This paper presents the use of Line Surge Arresters on 154kV double circuit lines. The ouatge rate which is highly related to the tower footing resistance is showed during the last a few year. The general methods that have been adopted at lines also are introduced. Lightning performance of lines without and with line surge arrester is studied and compared. The characteristics between air-gap type and gapless type LSA also compared. Line surge arrester installation strategy is presented.

• 정보저장시스템학회:학술대회논문집
• /
• 2005.10a
• /
• pp.59-63
• /
• 2005

Nowadays, various approaches are performed to increase the storage capacity of optical storage device. One of the promising candidates is using the high NA lens. By using high NA lens, the beam spot size can be reduced which will lead to increase the storage density. This paper proposes a double cantilever beam type bimorph PZT actuator for fine motion that can control the gap between the flexible media and optical pickup which uses high NA lens. Mathematical model is derived by using Hamilton's principle and the model is verified by finite element analysis and experiment. Position controller is designed and its performance is evaluated by experiment.

• Proceedings of the KIEE Conference
• /
• 2004.10a
• /
• pp.218-220
• /
• 2004

In this paper, the concept of contactless inductive power transfer system used for the PRT system is suggested and some ideas for Power transformer design to improve the power transfer performance are presented. This system has a large air-gap and demands a large electrical power capability But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding, which was divided in half to increase both output current and output voltage was suggested. In addition, the performance of power transformer alignment condition between the primary power line and the power collector was verified by computer simulation of 2kW model.