• 한국포장학회지
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• 제8권2호
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• pp.39-43
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• 2002

Increasing use of plastics in food packaging materials has led to the issue of food-plastic packaging materials's mutual interactions. Although the plastic packaging materials are generally considered as inert, migration and sorption of fatty materials are some of the problems associated with their use. So, this work investigated the compatibility of three structurally different polymers, polypropylene (PP), polyethyleneterephthalate (PET) and ethylene vinyl alcohol copolymer (EVOH) with some structurally different food fats. The main goal was to study the sorption of food fats by the plastic films and to see what extent mechanical properties of the plastic films was affected by plasticization effect due to sorption of fatty materials. PP, PET, and EVOH films was immersed in pure triglycerides, and then extracted with hexane and analyzed for the amounts of fat migrated. The sorbed films were also investigated for change in mechanical properties. Result showed that structural factor of the films and fatty materials plays important role in th migration process. The fat with the simplest structure are migrated more easily that the fat with more complex structure. However, structural effect of migration was varied according to degree of crystallinity and density of plastic films. In addition to that, polarity of plastic film was affected migration of fatty materials significantly. Additional research is needed to justify the reason why migration of fatty materials into the films was affected by polarity and structural integrity.

• 한국분말재료학회지
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• 제26권6호
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• pp.515-527
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• 2019

High-entropy alloys (HEAs) are generally defined as solid solutions containing at least 5 constituent elements with concentrations between 5 and 35 atomic percent without the formation of intermetallic compounds. Currently, HEAs receive great attention as promising candidate materials for extreme environments due to their potentially desirable properties that result from their unique structural properties. In this review paper, we aim to introduce HEAs and explain their properties and related research by classifying them into three main categories, namely, mechanical properties, thermal properties, and electrochemical properties. Due to the high demand for structural materials in extreme environments, the mechanical properties of HEAs including strength, hardness, ductility, fatigue, and wear resistance are mainly described. Thermal and electrochemical properties, essential for the application of these alloys as structural materials, are also described.

• Advanced Composite Materials
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• 제17권4호
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• pp.343-358
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• 2008

This present study provides the structural design and analysis of main wing, horizontal tail and control surface of a small scale WIG (Wing-in-Ground Effect) craft which has been developed as a future high speed maritime transportation system of Korea. Weight saving as well as structural stability could be achieved by using the skin.spar.foam sandwich and carbon/epoxy composite material. Through sequential design modifications and numerical structural analysis using commercial FEM code PATRAN/NASTRAN, the final design structural features to meet the final design goal such as the system target weight, structural safety and stability were obtained. In addition, joint structures such as insert bolts for joining the wing with the fuselage and lugs for joining the control surface to the wing were designed by considering easy assembling as well as more than 20 years service life.

• 한국압력기기공학회 논문집
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• 제13권1호
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• pp.75-83
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• 2017

This study investigated deformation behavior of major nuclear structural materials under cyclic loading conditions via cyclic stress-strain test. The cyclic stress-strain tests were conducted on SA312 TP316 stainless steel and SA508 Gr.3 Cl.1 low-alloy steel, which are used as materials for primary piping and reactor pressure vessel nozzle respectively, under cyclic load with constant strain amplitude and constant load amplitude at room temperature (RT) and $316^{\circ}C$. From the results of tests, the cyclic hardening and softening behavior, stabilized cyclic stress-strain behavior, and ratcheting behavior of both materials were investigated at both RT and $316^{\circ}C$. In addition, appropriate considerations for cyclic deformation behavior in the structural integrity evaluation of major nuclear components under excessive seismic condition were discussed.

• 한국산업융합학회 논문집
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• 제25권5호
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• pp.741-746
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• 2022

In this paper, structural analysis was conducted on the base frame for materials of the conveyor system that automatically produces nurungji. The materials of the base frame were selected as SS400, STS304, Al6063-5. Structural analysis performed Von-Mises stress and maximum displacement for 38 hot plates in real situation, and performed weight of distribution force for yield strength, and calculated safety factor. SS400 and STS304 have little displacement, but Al6063-5 is deformed to 0.149mm, which is 2.6 times greater than other materials. However, since the safety factor was calculated as 8.5, it can be applied to the applicable food processing equipment. The weight of the distributed force for the yield strength of the materials was 17.7kN for SS400, 14.7kN for STS304, and 10.2kN for Al6063-T5. When manufacturing other processed foods with a base frame of the same size, a material suitable for the corresponding weight should be selected.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.312-312
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• 2008

• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1712-1715
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• 2018

To study the applications for ferroelectric non-volatile memory and ferroelectric memristor, etc., deposition pressure dependent electric the properties of $(Hf,\;Zr)O_2$ thin films by RF sputtering deposition method were investigated. The bottom electrode was TiN thin film to produce stress effect on the formation of orthorhombic phase and top electrode was Pt thin film by DC sputtering deposition. Deposition pressure was varied along with the same other deposition conditions, for example, sputtering power, target to substrate distance, post-annealing temperature, annealing gas, annealing time, etc. The structural and electric properties of the above thin films were investigated. As a result, it is confirmed that the electric properties of the $(Hf,\;Zr)O_2$ thin films depend on the deposition pressure which affects structural properties of the thin films, such as, structural phase, ratio of the constituents, etc.

• 대한조선학회논문집
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• 제48권5호
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• pp.435-444
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• 2011

This paper deals with the structural assessment of metallic and non-metallic stiffened/monocoque plated marine structures under a lateral pressure load to identify appropriate combination of material and section configuration, especially at the preliminary marine structural design stage. A generic rectangular plated structure is exemplified from the metallic superstructure of a marine vessel and its structural topology is varied for the structural assessment. In total 13 different structural topologies are proposed and assessed using appropriate elastic solutions in conjunction with a set of stress and deflection limits obtained from practice. The geometry dimensions and weights of the structural topologies are calculated, and subsequently, the costs of the materials used in the structural topologies are reviewed to discuss the cost-effectiveness of the materials. Finally, conclusions are made with the aim of suggesting suitable structural topology for the marine structural member considered in this paper.

• Structural Engineering and Mechanics
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• 제62권5호
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• pp.577-585
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• 2017

To study the mechanical performances of prestressed steel-concrete composite box beam under combination of bending-shear-torsion, nine composite beams with different ratio of torsion to bending were designed. Torsion was applied to the free end of the beam with jacks controlled accurately with peripherals, as well as concentrated force on the mid-span with jacks. Based on experimental data and relative theories, mechanical properties of composite beams were analyzed, including torsional angle, deformation and failure patterns. The results showed that under certain ratio of torsion to bending, cracking and ultimate torsion increased and reached to its maximum at the ratio of 2. Three phases of process is also discussed, as well as the conditions of each failure mode.

• 한국CDE학회논문집
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• 제20권4호
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• pp.412-419
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• 2015

This paper presents the results of the structural analysis and the optimization of a 6,500 m manned submersible. Nonlinear structural analysis for imperfect spheres with the maximum allowable out-of-roundness(OOR) was performed to calculate the thickness of the pressure hull. Dimensions of viewports were determined according to ASME PVHO standard. The design optimization of the spherical hull with openings was divided into two steps - the optimization of the detailed shape of the viewport reinforcements and the optimization of the viewport location in the spherical pressure hull.