• Journal of Magnetics
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• v.18 no.1
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• pp.39-42
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• 2013

We studied the structural and electrical properties of $SrRuO_3$ thin films grown on $SrTiO_3$ (110) substrate. High resolution X-ray diffraction measurement of the grown film showed 1) very sharp peaks for $SrRuO_3$ film with a very narrow rocking curve with FWHM = $0.045^{\circ}$ and 2) coherent growth behavior having the same in-plane lattice constants of the film as those of the substrate. The resisitivity data showed good metallic behavior; ${\rho}$ = 63(205) ${\mu}{\Omega}{\cdot}cm$ at 5 (300) K with a residual resistivity ratio of ~3. The observed kink at ${\rho}(T)$ showed that the ferromagnetic transition temperature was ~10 K higher than that of $SrRuO_3$ thin film grown on $SrTiO_3$ (001) substrate. The observed rather lower RRR value could be partially due to a very small amount of Ru vacancy generally observed in $SrRuO_3$ thin films grown by PLD method and is evident in the larger unit-cell volume compared to that of stoichiometric thin film.

• Structural Engineering and Mechanics
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• v.46 no.6
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• pp.791-808
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• 2013

The main purpose of this paper is to develop seismic fragility curves for existing reinforced concrete, RC, buildings based on the post earthquake field survey and the seismic performance using capacity design. Existing RC buildings constitute approximately 65% of the total stock in Algiers. This type of buildings, RC, was widely used in the past and chosen as the structural type for the future construction program of more than 2 millions apartments all over Algeria. These buildings, suffered moderate to extensive damage after the 2003 Boumerdes earthquake, on May 21st. The determination of analytical seismic fragility curves for low-rise and mid-rise existing RC buildings was carried out based on the consistent and complete post earthquake survey after that event. The information on the damaged existing RC buildings was investigated and evaluated by experts. Thirty four (34) communes (districts) of fifty seven (57), the most populated and affected by earthquake damage were considered in this study. Utilizing the field observed damage data and the Japanese Seismic Index Methodology, based on the capacity design method. Seismic fragility curves were developed for those buildings with a large number data in order to get a statistically significant sample size. According to the construction period and the code design, four types of existing RC buildings were considered. Buildings designed with pre-code (very poor structural behavior before 1955), Buildings designed with low code (poor structural behavior, between 1955-1981), buildings designed with medium code (moderate structural behavior, between 1981-1999) and buildings designed with high code (good structural behavior, after 1999).

• International Journal of Concrete Structures and Materials
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• v.6 no.2
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• pp.101-110
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• 2012

This paper focuses on the finite element (FE) response sensitivity and reliability analyses considering smooth constitutive material models. A reinforced concrete frame is modeled for FE sensitivity analysis followed by direct differentiation method under both static and dynamic load cases. Later, the reliability analysis is performed to predict the seismic behavior of the frame. Displacement sensitivity discontinuities are observed along the pseudo-time axis using non-smooth concrete and reinforcing steel model under quasi-static loading. However, the smooth materials show continuity in response sensitivity at elastic to plastic transition points. The normalized sensitivity results are also used to measure the relative importance of the material parameters on the structural responses. In FE reliability analysis, the influence of smoothness behavior of reinforcing steel is carefully noticed. More efficient and reasonable reliability estimation can be achieved by using smooth material model compare with bilinear material constitutive model.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1081-1084
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• 2003

Structural morphology, annealing behavior and dielectric properties of polyaniline-emeraldine base (Pani-EB) and poly methyl methacrylate (PMMA) thin films prepared by spin coating technique have been studied. MIM and MISM structures were used to investigate annealing and dielectric behavior. The XRD and AFM spectrum of as grown and annealed thin films indicates the amorphous nature. The observed amorphous phase, low loss, dielectric behavior and thermal stability even at high temperatures implies the feasibility of utilizing PMMA and Pani-EB thin films as gate dielectric insulator layer in organic thin film transistors which can find application in flat panel display.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.695-705
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• 2015

Distressed structures require necessary remedial measures in order to restore their original structural properties like strength and stiffness. Validating the effectiveness of the proposed qualitative remedial measure experimentally is of utmost importance as there is no well-established analytical method to verify the effectiveness of the same quantitatively. Prototype testing which would have been the best option for this purpose would not only prove costly but also be associated with numerous practical difficulties; hence model testing is resorted as the only option for the purpose. This paper presents one such typical experimental study on the structural behavior of a distressed bridge, mainly observed in the form of prominent tilt in the bearing plate in transverse and longitudinal direction on downstream side. The main focus of the proposed experimental investigation is to assess the structural behavior particularly the load carrying capacity. The extent of deformation of some models with specific structural arrangements and some models with specific need based remedial measures were also studied. This study also assessed the contribution of each remedial measure towards restoration individually and collectively.

• Journal of Industrial Technology
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• v.17
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• pp.291-295
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• 1997

The tests of stress corrosion cracking in structural carbon steel were carried out under the conditions of acid fog and general water. As the result of measurement SCC rupture time under acid fog was observed to be much shorter than that of general water at the same stress level. Therefore, acid fog drops the SCC strength in structural carbon steel due to strong corrosion. In the SCC process by acid fog, crack initiation was caused by pit corrosion and local stress concentration, and distinctive feature of crack growth shows branching since crack grows to the corrosion direction. Moreover, corrosion products were observed by clevage corrosion on the crack surfaces.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.4
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• pp.45-53
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• 2022

In this study, the loading test and structural analysis were performed on the snow load and the results were compared. The load plates were loaded on the roof surface of the model, and structural analysis was performed under the same conditions. The result of loading test, the maximum displacement was observed in the center of the top, and the maximum stress was observed near the bottom point. Displacement and stress were found to have a high linear relationship with the load. Comparing the structural analysis results with the loading test results, the maximum displacement difference is 4.5% and the maximum stress difference is 10.2%. It is expected that closer results can be derived if the boundary conditions for the longitudinal direction of the model are clarified during experiments and analysis.

• Journal of Korean Vacuum Science & Technology
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• v.7 no.1
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• pp.13-17
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• 2003

The influence of structural transition on the resistance and impedance behavior of Ni$_2$MnGa alloy was investigated. The temperature-dependent resistance and impedance were measured in a temperature range of 4 - 350 K and 185 - 300 K, respectively. The dependence of temperature coefficient of resistivity on temperature shows a kink at 220 K, which is related to the structural transition. The change in dominant scattering mechanism results in the observed kink. Significant increases were also observed around the transition temperature for both real and imaginary parts of impedance. It is thought that this phenomenon originates from disappearance of the martensite twin boundaries during the structural transformation.

• Macromolecular Research
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• v.14 no.3
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• pp.318-323
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• 2006

We investigated the rheological behaviors and orientation of three different types of layered silicate composite systems under external flow: microcomposite, intercalated and exfoliated nanocomposites. Rheological measurements under shear and uniaxial extensional flows, two-dimensional, small-angle X-ray scattering and transmission electron microscopy were conducted to investigate the properties, as well as nano- and micro-structural changes, of polymer/layered silicate nanocomposites. The preferred orientation of the silicate layers to the flow direction was observed under uniaxial extensional flow for both intercalated and exfoliated systems, while the strain hardening behavior was observed only in the exfoliated systems. The degree of compatibility between the polymer matrix and clay determined the microstructure of polymer/clay composites, strain hardening behavior and spatial orientation of the clays under extensional flow.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.33-36
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• 2006

The purpose of this paper is to investigate the structural behavior of fire damaged high-strength SRC columns with polypropylene fiber. When high-strength concrete is exposed to high temperature, spalling is occurred then it leads to decrease the capacity of members. Polypropylene fiber is used to reduce the spalling of the specimens and the distinction in the behavior after fire is observed. High-strength concrete specimens were exposed to high temperatures by the ISO 834 curve. Main experimental parameters were the ratio of the contained polypropylene fiver, heating time and type of loading. Reduction rate in residual strength and stiffness is observed for the mixing of PP fiber, the heating time and eccentricity of loading.