• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.5
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• pp.3-9
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• 2007

In this study, the effect of the purification materials is analyzed and tested by Flow 3D and Hydraulic model test. Three dimension numerical analysis led from the research that sees abnormal form and the size back of the water purification material conferred the flowing water conduct inside the test channel against the test condition. Comparison it analyzed the flux distribution, a water depth of the channel which establishes the water purification materials the cross section, an interval of the water purification material, a conference with general channel, it change executed. As a result, the cross section ratio of the purification materials against and a flux change from the test which it sees. The interval of the purification materials in order to prevent three dimension that follows in decrease of increase and flux must decide an interval.

• Journal of Veterinary Clinics
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• v.11 no.1
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• pp.377-381
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• 1994

This study was performed to investigate the usefulness of the radiopaque material as a disintegration test of enteric coated capsules radiologically. The results obtained were as follows; 1. The times that the enteric coated capsules passed the pylorus(GI transition times) were the first 150 minute and the last 390 minutes. Therefore, the GI transition times largely differ from each animal and each enteric coated capsule. 2. The disintegration times of enteric coated capsules were similar in vitro test and in vitro test. 3. The disintegration test of enteric coated capsules using Barium sulfate, radiopaque material for the gastrointestinal track, was useful to check the time pass through the pylorus and the time enteric coated capsules were disintegration.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.391-398
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• 1995

This study was carried to investigate the usefulness of the radiopaque material as the GI transition and disintegration test of enteric coated capsules radiologically. The obtained results were as follows; 1. The GI transition times that the enteric coated capsules pass through the pylorus were that the time of the first capsule was 210 minutes and the time of the last capsules was more than 300 minutes. Therefore, the GI transition times largely differ from each animal and each enteric coated capsule. 2. The disintegration times of enteric coated capsules were similar in vitro test and in vivo test. 3. The GI transition and disintegration test of enteric coated capsules using barium sulfate, radiopaque material for the gastrointestinal track, was useful to investigate the times that the capsules passed through the pylorus and disintegrated in intestinal track.

• Smart Structures and Systems
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• v.10 no.6
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• pp.547-555
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• 2012

Measuring crack length in concrete fracture test is not a trivial problem due to high speed crack propagation. In this study, mechanoluminascent (ML) material, which emits visible light under stress condition, was employed to visualize crack propagation during concrete fracture test. Three-point bending test was conducted with a notched concrete beam specimen. The cracking images due to ML phenomenon were recorded by using a high speed camera as a function of time and external loadings. The experimental results successfully demonstrated the capability of ML material as a promising visualization tool for concrete crack propagation. In addition, an interesting cracking behavior of concrete bending fracture was observed in which the crack propagated fast while the load decreased slowly at early fracture stage.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.382-383
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• 2005

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.35-41
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• 2014

PURPOSES : Surface treatment is a favorable method in the pavement preventive maintenance. This study (Part I) aimed to develop the low viscosity filling material for waterproof characteristics and high penetrable and weather resistance, and a series of companion study (Part II) presents the coating characteristics and performance analysis using field and lab tests. METHODS : Hydrophobic characteristics of the advanced surface treatment material are observed and measured the filling depth and the permeability for sand and asphalt pavement specimen using the water absorption test and permeability test, X-RAY CT test. Color difference for the weather resistance using ultraviolet ray accelerated weathering test is compared with asphalt pavement specimens. RESULTS : The developed material shows the decreased water absorption and increased impermeable effect because of the hydrophobic characteristics. It is found that the filling depth is about 6mm and weather resistance is better than asphalt pavement specimen. CONCLUSIONS : The advanced hydrophobic - low viscosity filling treatment material is developed in this study (Part I) to improve the waterproof characteristics and high filling capacity and weather resistance for the pavement preventive maintenance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.7
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• pp.2246-2256
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• 1996

To investigate the effect of material and precess variables on stamping formability of sheet materials, simulations for the cup drawing and the Yoshida buckling test were carried out using ABAQUS, commercial nonlinear finite element analysis code. The various factor effects on stamping formability of sheet materials were analyzed by the designed process according to Taguch's orthogonal array experiment. Cup drawing simulation showed that local neckling was very sensitive to plastic anisotropy parameter of sheet material and friction coefficient between sheet and tool interface. Simulations for the Yoshida buckling test have clarified that buckling behaviour of sheet material was mostly susceptible to yield stress and sheet thickness mostly. However, plastic anisotropy parameter and strain hardening coefficient affect moderately buckling behaviour of steel sheets after the buckling initiation.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.6
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• pp.19-27
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• 2018

The stone pagoda structure is treated as a discontinuous masonry structure, and the contact surface characteristics between stones is a very important factor in the discontinuum behavior analysis. So, it is necessary to find out material and structural characteristics of stone contact surface to perform the structural analysis for safety evaluation. Accordingly, it is important to analyze the material properties of stone surface and secure the structural characteristics through various contact surface states. Therefore, in this study, various test specimens applying the filler between the surface roughness and the stone in the contact surface treatment technique of the stone pagoda were manufactured, and compression test and shear test were carried out. Also, we analyzed the material and structural characteristics of the stone contact surface through the comparison of experimental results.

• International Journal of Highway Engineering
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• v.16 no.5
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• pp.9-18
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• 2014

PURPOSES : The objective of this study is to evaluate the applicability of the pitch, which is produced during SDA petroleum upgrading process, as a pavement paving material. In order for the purpose, the physical and chemical properties of the pitch are analyzed, and then the various plasticizers are applied in the pitch. METHODS : Two types of pitch are selected from oil refinery companies, which are owned the SDA petroleum upgrading process. Also, two types of asphalt binders, PG 64-22 and PG 58-22, are employed to compare with the pitch because these two types of asphalt binders are currently used as paving materials. For the chemical property of the pitch, the composition of SARA (Saturate, Aromatic, Resin, Asphaltene), the elementary composition, and the functional group are analyzed. For the physical property of the pitch, the basic material property tests, such as penetration test, softening point test, flash point test, ductility test, and rotational viscometer test, are performed. Also, the DSR (Dynamic Shear Rheometer) test and the BBR (Bending Beam Rheometer) test are conducted using asphalt binder specimens obtained by both short term aging (Rolling Thin Film Oven, RTFO) and long term aging (Pressure Aging Vessel, PAV) processes. The rheological property of each pitch type is evaluated as a function of temperatures and loading cycles. PG 64-22 asphalt binder is used as a control material. RESULTS AND CONCLUSIONS : The Pitch may not be suitable for the pavement paving material without modifications, but the pitch can be used as alternatives of modified addictive or asphalt. If low molecular component, such as saturate and aromatic components, are added in the pitch based on the development of various plasticizers, it has a strong possibility for the pitch to be used as a alternative. However, in order to verify the performance property of the pitch, further research is needed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1398-1407
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• 2000

The structural steels of power plant show the decrease of mechanical properties due to degradation such as temper embrittlement, creep damage and softening during long-term operation at high temper ature. The typical causes of material degradation damage are the creation and coarsening of carbides(M23C6, M6C) and the segregation of impurities(P, Sb and Sn) to grain boundary. It is also well known that material degradation induces the cleavage fracture and increases the ductile-brittle transition temperature of steels. So, it is very important to evaluate degradation damage to secure the reliable and efficient service condition and to prevent brittle failure in service. However, it would not be appropriate to sample a large test piece from in-service components. Therefore, it is necessary to develop a couple of new approaches to the non-destructive estimation technique which may be applicable to assessing the material degradation of the components with not to influence their essential strength. The purpose of this study is to propose and establish a new electrochemical technique for non-destructive evaluation of material degradation damage for Cr-Mo steels which is widely used in the high temperature structural components. And the electrochemical anodic polarization test results are compared with those of semi-nondestructive SP test.