• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.987-988
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• 2004

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.304-310
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• 2014

The conventional methods for total residual chlorine such as iodometry and DPD colorimetric can cause secondary pollution due to additional agents, also have a wide error range. As for alternative, electrochemical method can measure TRC(Total residual chlorine), and is not required as additional agents, also very suitable for using the fields of ballast water because test time is relatively fast. Therefore, this study was investigated for changing charge by agitation, salt concentration, and temperature change. Charge showed differences based on changes of reduction peak with or without agitation. In contrast, TRC and charge were well correlated in constant agitation speed. As TRC and charge were analyzed with high correlations in constant salinity and temperature of ocean, thereby conductivity was firstly measured, and charge had high correlation for TRC in spite of changing salinity and temperature Pt electrode revealed high reliability ($r^2=0.960$) because it was rarely effected by TRC, On the other hand, Au electrode appeared inadequate ($r^2=0.767$) to use sensor in less than 1.0 ppm of TRC. For high accuracy and detection of TRC, Pt and Au electrodes for test time were, respectively, 14 and 22 seconds. As a result, Pt electrode was more valuable than Au electrode in terms of response time.

• Earthquakes and Structures
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• v.8 no.6
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• pp.1277-1297
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• 2015

Post-tensioned precast segmental bridge columns have shown high level of strength and ductility, and low residual displacement, which makes them suffer minor damage after earthquake loading; however, there is still lack of confidence on their lateral response against severe seismic loading due in part to their low energy dissipation capacity. This study investigates the influence of major design factors such as post-tensioning force level, strands position, columns aspect ratio, steel jacket and mild steel ratio on seismic performance of self-centring segmental bridge columns in terms of lateral strength, residual displacement and lateral peak displacement. Seismic analyses show that increasing the continuous mild steel ratio improves the lateral peak displacement of the self-centring columns at different levels of post-tensioning (PT) forces. Such an increase in steel ratio reduces the residual drift in segmental columns with higher aspect ratio more considerably. Suggestions are proposed for the design of self-centring segmental columns with various aspect ratios at different target drifts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.282-285
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• 2004

Kinetics of H-spillover over $Pt/MoO_3$ was greatly affected by the amount of residual chlorine differing by calcination temperature. Multifacetted techniques for characterization were dedicated to elucidate the faster reduction of chlorine in the isothermal reduction (ITR) at $50^circ{C}$ after calcination. Reduction of residual chlorine over Platinum resulted in opening the more channel of hydrogen pathway into more $MoO_3$ particles and controlling the kinetics of hydrogen uptake.

• Steel and Composite Structures
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• v.32 no.3
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• pp.373-388
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• 2019

This study proposes a new concept of an axial damper using the combination of shape memory alloy (SMA), friction devices, and polyurethane springs. Although there are many kinds of dampers to limit the damages, large residual deformation may happen and it causes much repairing cost for restoring the structure to the initial position. Also in some of the dampers, a special technology for assembling and fabricating is needed. One of the most important advantages of this damper is the ability to remove all the residual deformation using SMA plates and simple assembling without any special technology to fabricate. In this paper, four different dampers (in presence or omission of friction devices and polyurethane springs) are investigated. All four cases are analyzed in ABAQUS platform under cyclic loadings. In addition, the SMA plates are replaced by steel ones in four cases, and the results are compared to the SMA dampers. The results show that the axial polyurethane friction (APF) damper could decrease the residual deformation effectively. Also, the damper capacity and dissipated energy could be improved. The analysis showed that APF damper is a good recentering damper with a large amount of energy dissipation and capacity, among others.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.241-245
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• 2007

The residual stress in axial stress in the axial direction of the steel filaments has been measured by using a method based on the combination of the focused ion beam (FIB) and high resolution strain mapping program (VIC-2D). That is, the residual stress was calculated from the measured displacement field before and after the introduction of a slot along the steel filaments. The displacement was obtained by the digital correlation analysis of high-resolution scanning electron micrographs, while the slot was introduced by FIB milling with low energy beam. The present measurement revealed that the residual stress within 8% of the magnitude was persistent in the steel filaments fabricated.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.105-108
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• 2005

In damage investigation of building structures suffering from earthquake, estimation of residual seismic capacity is essential in order to access the safety of the building against aftershocks and to judge the necessity of repair and restoration. It has been proposed that an evaluation method for post-earthquake seismic capacity of reinforced concrete buildings based. on the residual energy dissipation capacity (the residual seismic capacity ratio )in lateral force-displacement curve of structural members. The proposed method was adopted in the Japanese 'Damage Level Classification Standard' revised in 200l. To evaluate the residual seismic capacity of RC column, experimental tests with positive and negative cyclic loading was carried out using RC building column specimen. Parameters used by the experiment are deformability and member proportion. From the test results, it is appropriated that the residual seismic capacity of RC buildings damaged by earthquakes is evaluated using the method in the Guideline.

• Transactions of Materials Processing
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• v.16 no.4 s.94
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• pp.323-328
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• 2007

The residual stress in axial direction of the steel wires has been measured by using a method based on the combination of the focused ion beam(FIB) milling and digital image correlation(DIC) program. The residual stress is calculated from the measured displacement field before and after the introduction of a slot along the steel wires. The displacement is obtained by the digital correlation analysis of high-resolution scanning electron micrographs, while the slot is introduced by FIB milling with low energy beam. The experimental procedures are described and the feasibilities are demonstrated in steel wires fabricated with different conditions. It reveals that the tensile residual stress is formed in all steel wires and this is strongly influenced by the fabrication conditions.

• Journal of Hydrogen and New Energy
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• v.17 no.3
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• pp.286-292
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• 2006

Chlamydomonas reinhardtii is a green algae that can use light energy and water to produce hydrogen under anaerobic condition. This work reports the effect of limiting factors on hydrogen production in sulfur deprived anaerobic C. reinhardtii culture. In order to confirm the relationship between hydrogen production and limiting factors such as residual PSII activity and endogenic substrate degradation, the increase in chlorophyll concentration and the decrease in starch concentration was investigated during sulfur deprivation. The overall hydrogen production increased depending on cell density in range of $0.4{\sim}0.96\;g$ DCW/l. At this time, the increase in chlorophyll concentration during 24 h after sulfur deprivation increased in proportion to hydrogen production, however, the decrease in starch concentration was not proportional to that. Therefore, hydrogen production under sulfur deprivation using green alga was closely associated with the residual PSII activity than the endogenic substrate degradation.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.173-180
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• 2004

The tread pattern of a tire has an important effect on tire performances such as handling, wear, noise, hydroplaning and so on. However, a finite element analysis of a patterned tire with detailed tread blocks has been limited owing to the complexity of making meshes for tread blocks and the huge computation time. The computation time has been shortened due to the advance in the computer technology. The modeling of tread blocks usually requires creating a solid model using a CAD software. Therefore it is a very complicated and time-consuming job to generate meshes of a patterned tire using a CAD model. A new efficient and convenient method for generating meshes of a patterned tire has been developed. In this method, 3-D meshes of tread pattern are created by mapping 2-D meshes of tread geometry onto 3-D tread surfaces and extruding them through tread depth. Then, the tread pattern meshes are assembled with the tire body meshes by the tie contact constraint. Residual aligning torque and frictional energy are calculated by using a patterned tire model and compared to the experimental results. It is shown that the calculated results of a patterned tire model are in a good agreement with the experimental ones.