• Steel and Composite Structures
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• v.2 no.1
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• pp.35-50
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• 2002

A series of tests on simple-welded plate specimens (SWPS) and T-stub tension specimens simulating some of the joint details in moment frame connections were conducted in this investigation. The effects of weld strength mismatch and weld metal toughness on structural behavior of these specimens were considered under both static and dynamic loading conditions. Finite element analyses were performed by taking into account typical weld residual stress distributions and weld metal strength mismatch conditions to facilitate the interpretation of the test results. The major findings are as follows: (a) Sufficient specimen size requirements are essential in simulating both load transfer and constraint conditions that are relevant to moment frame connections, (b) Weld residual stresses can significantly elevate stress triaxiality in addition to structural constraint effects, both of which can significantly reduce the plastic deformation capacity in moment frame connections, (c) Based on the test results, dynamic loading within a loading rate of 0.02 in/in/sec, as used in this study, premature brittle fractures were not seen, although a significant elevation of the yield strength can be clearly observed. However, brittle fracture features can be clearly identified in T-stub specimens in which severe constraint effects (stress triaxiality) are considered as the primary cause, (d) Based on both the test and FEA results, T-stub specimens provide a reasonable representation of the joint conditions in moment frame connections in simulating both complex load transfer mode and constraint conditions.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.253-260
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• 2001

Rotating bogie frame will be used in the bogie for the Light Rail Train being developed. In development of the bogie, analyzed were the structural strength and fatigue characteristics of the rotating bogie frame. Defined load cases were applied for the analysis. No part of the rotating bogie frame is subjected to stress beyond the fatigue endurance limits of the material used when grinding the weldment of the lower plate link bend. It is concluded that the rotating bogie frame is considered safe in the view of the structural strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.272-275
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• 2004

This study is to propose a modified equivalent frame method under lateral loading. ACI 318-02 allows the equivalent frame method to conduct slab analysis subjected to lateral loads. However, current method can not predict the behavior of the slabs particularly under lateral loading because the equivalent frame method in the ACI 318 has been developed against gravity loads. This study provides more precise model for the analysis of the flat plate slabs under lateral loading. The model reflect the force transfer mechanism of slabs, column and torsional member more accurately than the existing model. The accuracy of this model is verified by compared with finite element method analysis results.

• Microbiology and Biotechnology Letters
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• v.5 no.4
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• pp.159-165
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• 1977

20 pesticides induding 11 insecticides, 5 herbicides and 4 fungicides have been tested for mutagenic activity in the Salmonella microsome system. It was found that Captan showed strong mutagenic activity directly in TA 1535, TA 100 and TA 98 strains, indicating that it induces both base substitution and frame shift mutation. With microsomal activation system, mutagenicity of Captan was slightly decreased. Micut, Dimethoate and Triforine revealed slight mutagenicity in TA100 without microsmal enzyme activtion.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.457-468
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• 2006

An experimental study was performed to investigate the maximum energy dissipation and the ductility capacity of shear-dominated steel plate walls with thin web plates. Three specimens of three-story plate walls with thin web plates were tested. The parameters for the test specimens were the aspect ratio of the web plate and the shear strength of the column. A concentrically braced frame and a moment-resisting frme were a also tested for comparison. The steel plate walls exhibited much better ductility and energy dissipation capacity than the concentrically braced frame and the moment-resisting frame. The results showed that unlike other structural systems, the sh as well as strength, and can therefore be used as an effective earthquake-resisting system. A method of predicting the energy dissipation capacity of a steel plate wall was proposed.

• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.115-125
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• 2009

An experimental study was performed to investigate the cyclic behavior of the reinforced concrete frame with infilled steel plate. For this purpose, three-story compositewalls using infilled steel plates (RCSPW) were tested. The parameters for this test were the reinforcement ratio of the column and opening in the infilled steel plate. A reinforced concrete infilled wall (RCIW) and a reinforced concrete frame (RCF) were also tested for comparison. The deformation capacity of the RCSPW specimen was significantly greater than that of the RCIW specimen, although the two specimens exhibited the same load-carrying capacity. Like the steel plate walls with the steel boundary frame, RCSPW specimens showed excellent strength, deformation capacity, and energy dissipation capacity. Furthermore, by using infilled steel plates, shear cracking and failure of the column-beam joint were prevented. By using a strip model, the stiffness and strength of the RCSPW specimens were predicted. The results were compared with the test results.

• Steel and Composite Structures
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• v.29 no.6
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• pp.771-783
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• 2018

In this paper, topology optimization (TO) is applied to find a new configuration for the perforated steel plate shear wall (PSPSW) based on the maximization of reaction forces as the objective function. An infill steel plate is introduced based on an experimental model for TO. The TO is conducted using the sensitivity analysis, the method of moving asymptotes and SIMP method. TO is done using a nonlinear analysis (geometry and material) considering the buckling. The final area of the optimized plate is equal to 50% of the infill plate. Three plate thicknesses and three length-to-height ratios are defined and their effects are investigated in the TO. It indicates the plate thickness has no significant impact on the optimization results. The nonlinear behavior of optimized plates under cyclic loading is studied and the strength, energy and fracture tendency of them are investigated. Also, four steel plates including infill plate, a plate with a central circle and two types of the multi-circle plate are introduced with equal plate volume for comparing with the results of the optimized plate.

• The KSFM Journal of Fluid Machinery
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• v.19 no.6
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• pp.68-74
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• 2016

Hydraulic fracturing of wells during oil and gas (O&G) exploration consumes large volumes of fresh water and generates larger volumes of contaminated wastewater with high salinity. It is critical to treat and reuse the O&G wastewater in a cost-effective and environmentally sound manner for sustainable industrial development and for meeting stringent regulations. Recently, forward osmosis (FO) has been examined if it is a promising solution for treatment and desalination of complex industrial streams and especially fracturing flowback and produced waters. In the present study, the performances of a plate-and-frame FO membrane element and a module (6 elements combined in series) were investigated for concentrating high TDS wastewater. An FO module has achieved up to 64 % water recovery (i.e., concentration factor of 2.76) from 10,000 ppm wastewaters and can concentrate feed streams salinities to greater than 30,500 ppm.

• Journal of Environmental Science International
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• v.7 no.2
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• pp.209-216
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• 1998

Nanofiltration[NF45] and reverse osmosis membrane(HR98PP) separation treatment of dyestuff wastewater was carried out In order to separate relatively pure water from synthetic dyestuff wastewater, which consists of reactive dye, acid dye, basic dye, direct dye, and disperse dye. The experiments were performed by using the plate and frame membrane module. In the nanofiltration and reverse osmosis membrane separation, When the NaCl concentration was 0.1, 5.0, and 20.091, retention was 63.0, 46.0, 0.9%, respectively. When permeate flux was 125.0, 67.5, and 45.0 L/$m^2$ h, the osmotic pressure increased with Increasing the NaCl concentration. Permeate flux of two membranes Increased as temperature Increased due to segmental movement of polymer of the membrane and the rejection rate of dyestuff was decreased gradually. It was found that the rejection rate was about 95% in the nanofiltratlon, while the reverse osmosis membrane showed a high rejection rate of 99% under all temperature and pressures conditions.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.609-613
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• 2004

An economic analysis is one of the most dominant factors to determine the project feasibility of super tall building. In economic considerations, it is very important toadopt optimum structural floor systems because these are dependent on both the cost and the duration of construction. The economics affected by structural floor systems are more distinct athigher story. As the story increases, the construction cost of floor system. is accumulated linearly, while the cost of lateral resisting system is increased geometrically. The purpose of this study is to investigate the economical effects of super tall buildings through application of optimum structural floor systems. Three types of structural systems(RC beam-column frame, RC flat plate frame, and Steel frame) of super tall buildings having 50-stories are considered in this study and compared to RC flat plate slab with other systems. Analytical result shows that RC flat plate slab using lightweight concrete ismost effective in both the cost and the duration of construction.