• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.261-269
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• 2008

This experiment was performed to investigate the anxiolytic-like effects of cyclopeptide fraction alkaloids of Zizyphi Spinosi Semen (CFAZ), by using the experimental paradigms of anxiety, and compared with those of a known anxiolytic, diazepam. CFAZ (8.0 mg/kg, p.o.) increased the percentage of time spent on the open arms and the number of open arms entries in the elevated plus-maze test, increased the number of head dips in the hole-board test, and increased the percentage of center zone ambulatory time in the open-field box. However, CFAZ has no effect on the locomotor activity, while diazepam (2.0 mg/kg, p.o.) significantly reduced locomotor activity. CFAZ did not influence the grip force in the grip strength meter test, either. From the molecular experiments, CFAZ increased chloride influx in cultured cerebellar granule cells. In addition, $GABA_A$ receptors $\gamma$-subunit were over-expressed by CFAZ in cultured cerebellar granule cells. It is concluded that CFAZ may have anxiolytic-like effects, and these effects may be mediated by $GABA_A$ receptors.

• Journal of Life Science
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• v.24 no.3
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• pp.290-296
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• 2014

The present experiment investigated putative anxiolytic-like effects of quercetin using an elevated plus-maze (EPM) and hole-board apparatus test in mice. Quercetin is a flavonoid widely distributed in nature. Quercetin (1.25, 2.5, 5, or 10 mg/kg) was orally administered to ICR mice 1 h before a behavioral evaluation in the EPM. Control mice were treated with an equal volume of vehicle, and positive control mice were treated with buspirone (2 mg/kg, i.p.). The mice administered quercetin (5 mg/kg) spent a significantly longer percentage of time in the open arms of the EPM and their percentage of entries into the open arms was significantly increased compared to the vehicle-treated controls (p<0.05). The anxiolytic-like activities of quercetin were antagonized by trans-4-aminocrotonic acid (a $GABA_{A-{\rho}}$ agonist, 20 mg/kg) but not by flumazenil (a $GABA_A$ antagonist, 10 mg/kg) or WAY-100635 (a $5-HT_{1A}$ antagonist, 0.3 mg/kg). Moreover, there were no changes in the locomotor activity or myorelaxant effects in any group compared with the vehicle-treated controls. In the hole-board apparatus test, the number of head-dips increased significantly in the single treatment with quercetin (5 mg/kg) group compared to the vehicle-treated controls (p<0.05). These findings suggest that quercetin can promote anxiolytic-like activity, mediated by the GABAergic nervous system, in mice.

• Composites Research
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• v.36 no.5
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• pp.303-309
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• 2023

In this paper, a Progressive Damage and Failure Analysis (PDFA) modeling method was developed using ABAQUS/EXPLICIT to predict in-plane damage and delamination for Open-Hole Compression (OHC) testing. The proposed PDFA model was constructed based on Hashin criteria and cohesive behavior. The strength and stiffness of OHC specimens with three types of stacking sequences [(45/-45/0₂)₃]_s , [(45/0/-45/90)₃]_s and [45/-45/0/45/-45/90/(45/-45)₂]_s were compared to comprehensively evaluate the validity of the Finite Element(FE) model of PDFA. The strength and stiffness of the OHC specimens were predicted relatively well, with less than a percentage error 10.0 %. For the numerical simulation case for each layup, the damage initiation/evolution of OHC specimens were evaluated for delamination and tension/compression matrix damage before and after failure.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.300.2-300.2
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• 2013

Periodically shaped pillar-arrays and hole-arrays were fabricated on a Si wafer. Geometric features are similar in a periodic length of 4 ${\mu}m$ and a depth of 2 ${\mu}m$. For the hole-array patterns, positive PR processes were performed. UV exposed PR patterns were removed during a developing process to leave shapes of inversely replicated from a glass photomask. Meanwhile, negative PR processes were taken for the pillar-array patterns. UV exposed PR patterns were remained on a Si substrate having a same feature of patterns of a glass photomask. For an electrical aspect, a pillar structure has a short carrier-collection length resulting in the improved open-circuit voltage of 609 mV from 587 mV of a planar device. An improved performance may be achieved to reduce recombination loss along the patterning surface.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.143-149
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• 2000

Grinding technology in morden industry society is focusing on research and development for grinding stone and machin-ing parts for the purpose of high accuracy and high efficiency of products. But in order to equip the high technology and high accuracy of micro stone which is one of grinding stone a continuous effort on R& D is require. In this study the honing processing work of 2 cycle engine cylinder for motorcycle which has an open hole is carried out so as to investigate the boring and hone stone effects on accuracy of honing. As the experimental result of this study we could conclude that it is possible to secure good conditions of honing by controlling and keeping appropriate cycle-time in the stage of boring for the prior step of honing.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.104-107
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• 2006

Numerical analysis on laminated plates containing an open hole subjected to compression is conducted to predict the damage constitutive behaviour of the plates. A micromechanical constitutive model for unidirectional laminated composites proposed by Liang et a1. (2006), in conjunction with damage models (Karihaloo and Fu, 1989, 1999; Zhao and Weng, 1996, 1997), is implemented into the finite element code ABAQUS to conduct the numerical analysis. The predictions are compared with experiments (Lessard and Chang, 1991) to verify the accuracy of the present analysis.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.326-331
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• 1999

Grinding technology in morden industry society is focusing on research & development for grinding stone and machining parts for the purpose of high accuracy and high efficiency of products. But, in order to equip the high technology and high accuracy of micro stone which is one of grinding stone, hardly and continuous effort on R&D is required.In this study, honing processing work of 2-cycle engine cylinder for motorcycle which has open hole is practiced so as to clear how borning that is prior step of honing and hone stone make an influence on accuracy of honing. As the result of analyzing the results of experiments, we came to conclusion that we can secure good conditions of honing by controlling and keeping appropriate cycle-time in the stage of boring of prior step of honing.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.605-614
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• 1995

In the automatic transmission using planetary gear there exists nonlinearities due to the finite difference between gear ratios, which yield torque hole during shift and influence on the ride quality and life of clutch. Based on the reaction carrier and converter turbine speed sliding functions are defined. Nonlinear closed-loop control laws are derived using them. Computer simulation shows that the closed loop design is better than the open loop design and semi-closed loop design.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.47-51
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• 2015

In the study, a new non-open cut tunnel steel pipe method using slot hole has been developed. As is overcomes shortcomings of conventional methods, it is applied to the field. The main concept of the new method is the steel pipe pumping system with slot holes which, by means of formation slot holes between each steel pipe, applied to the magnitude of the relaxed earth pressure caused by excavation to the ground to prevent ground displacement. The stability of the support members and effect of displacement control of the new method were verified through several ways as numerical analysis and site test. The new method was applied to the construction of a 11.5m wide, 7.4m high and 50m long section that passes side subway and large buildings in inner city. By applying the new method, tunnel construction was successfully completed in 6 months. It decreases the construction period to 30% compared to that of conventional methods, and ground was almost negligible.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.83-87
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• 2012

Computational Fluid Dynamics (CFD) method has been used to investigate the axial force of automotive water pump. As the excessive axial force can make some unexpected problems like impeller interference and coolant leakage we have focused on finding the cause of axial force and its reduction in this paper. First, we have tested the closed type water pump with and without balance hole by the calculation methods. By examining the pressure contour around the impeller, we have found that the axial force arises not only from the pressure difference around shroud but also from the pressure difference around hub. So we have tested two impellers - one is normal open type impeller and the other is open type impeller with modified hub. The results show that the axial force reduction is about 150~200N for normal one and 700N@3000RPM for modified impeller. And the hydraulic efficiency which is important in aspect of engine fuel efficiency is reduced about 6.5% for normal one but increased 4%@3000RPM for modified impeller.