• 한국안전학회지
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• 제35권3호
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• pp.32-42
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• 2020

In this study, in order to secure the necessity of introducing the safety certification system for the assembled temporary equipment and materials, the feasibility of the introduction was analyzed through literature review, structural analysis, and actual experiments and surveys related to the assembled temporary equipment and materials. In the previous studies, it was found that the research on the assembled temporary equipment and materials was insufficient, and it was possible to grasp the necessity of introducing the safety certification system for the assembled temporary equipment and materials. In addition, in the results of the serious accident analysis, it was found that the soundness of the temporary equipment and materials is determined by the structural characteristics after it was assembled. As a result of the feasibility analysis of the introduction of the safety certification of the assembled temporary equipment and materials through structural analysis, it is possible to effectively and rationally reflect the main geometrical influence factors, and to introduce the safety certification system that can test the procedures and procedures of the assembled temporary equipment and materials and based on it. It was found that there is a need. As a result of feasibility analysis on the necessity of introducing the safety certification system for assembled temporary equipment and materials through actual experiments, the existing single member performance evaluation has limitations in evaluating the structural performance of the assembled temporary equipment and materials. It was found that there is a need to introduce a safety certification system. As a result of gathering opinions on the feasibility of introducing the safety certification system for assembled temporary equipment and materials of manufacturers and users through the survey, it was found that the overall positive response result was high and the effectiveness was high.

• Nano
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• 제13권12호
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• pp.1850145.1-1850145.8
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• 2018

In this study, a double-solvent radiation method is proposed to prepare silver nanoparticles in the pores of metal-organic framework MIL-101(Cr). The results reveal that well-dispersed silver nanoparticles with a diameter of about 2 nm were successfully fabricated in the cages of monodisperse octahedral MIL-101(Cr) with a particle size of about 400 nm. The structure of MIL-101(Cr) was not destroyed during the chemical treatment and irradiation. The resulting Ag/MIL-101 exhibits excellent catalytic performance for the reduction of 4-nitrophenol. This method can be extended to prepare other single or bimetallic components inside porous materials.

• Nuclear Engineering and Technology
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• 제50권5호
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• pp.683-689
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• 2018

To evaluate equipment survivability of the polymer Viton, used in sealing materials, the effects of its thermal degradation were investigated in severe accident (SA) environment in a nuclear power plant. Viton specimens were prepared and thermally degraded at different SA temperature profiles. Changes in mechanical properties at different temperature profiles in different SA states were investigated. The thermal lag analysis was performed at calculated convective heat transfer conditions to predict the exposure temperature of the polymer inside the safety-related equipment. The polymer that was thermally degraded at postaccident states exhibited the highest change in its mechanical properties, such as tensile strength and elongation.

• 한국안전학회지
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• 제29권3호
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• pp.8-13
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• 2014

Accidents involving portable ranges occurred total 133 cases for the last five years(2008~2012). It accounted for 18.0% of all gas accidents(739 cases). Major causes of accidents are using of excessive hot grill, leaving a butane can near fire and overheating of a butane can during cooking. In this study, it is a desire to investigate the relationship between thermal behavior mechanism depending on characteristics of cooking equipment materials of portable gas ranges. It shows that slope of temperature change curve correlates with difference of heat capacity on thermal behavior characteristics experiment depending on materials of cooking equipment. In conclusion, temperature characteristics appear differently depending on variables such as materials of cooking equipment. Especially, it is necessary to restrict using cooking equipment made of stones, because it is very dangerous that temperature of can is rapidly increasing caused by high heat capacity of stone.

• Advances in nano research
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• 제14권3호
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• pp.273-284
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• 2023

Combating the worldwide environmental threat of plastic waste pollution has become a priority. Plastic pollution has the potential to impact land, rivers, and seas, since many marine and terrestrial organisms have perished as a result of plastic's non-biodegradability and soil dangers. For this consumption, it seems required to manufacture and use new renewable resources. Renewable materials for diverse applications have been created utilizing nanotechnology, which may replace conventional materials for children's activities and sports equipment. This study investigates and suggests that nanotechnology-based materials be replaced with conventional materials to save the environment in manufacturing equipment for children's physical activities. On the basis of the mechanical sciences, a stability study of the bending behavior of small-scale structures will be performed for the various recommended materials.

• 한국융합학회논문지
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• 제12권2호
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• pp.279-285
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• 2021

소재·부품·장비 산업은 제조업의 허리이자 경쟁력의 핵심 요소가 되고 있다. 그러나 우리나라의 경우 핵심 소재·부품·장비를 해외에 의존하다 보니 산업경쟁력뿐만 아니라 안보적 측면에서도 커다란 위험 상황에 처하게 되었다. 본 연구는 먼저 소재·부품·장비 산업의 개요와 현주소를 살펴보고 그 문제점과 개선점을 파악하고 우리나라 소재·부품·장비의 국산화를 위한 그동안의 노력과 실적을 살펴보았다. 또한, 정부의 소재·부품·장비 산업에 대한 제도적인 차원이나 생태계적인 차원에서 그 개선방안을 살펴본 후 지역 소재·부품·장비의 국산화의 현황과 실태를 조사해보고 이에 따른 문제점과 개선점을 분석해 보았다. 마지막으로 본 연구는 지역 부품·소재 국산화를 위한 기술개발방안 및 사업화와 관련한 다양한 제도개선방안을 제시하였다.

• 한국생산제조학회지
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• 제24권5호
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• pp.530-534
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• 2015

Ultrasonic nanocrystal surface modification (UNSM) is an example of a nanoscale-surface modification that has become noticeable because of its effects on the mechanical improvement of metallic materials. UNSM equipment needs to be both utilized and improved. The equipment is based on an ultrasonic waveguide whose role is to strike surfaces of metallic materials to achieve nanoscale deformation. In this paper, we introduce the development of one kind of UNSM equipment. Using piezoelectric elements, we repeatedly design and fabricate a 20-kHz ultrasonic waveguide. With respect to the composition of the equipment, the waveguide is automatically transferred by two axial stages automatically. In addition, a static force is constantly applied by pneumatic devices. We perform an experiment to verify the feasibility of the equipment.

• 한국산업융합학회 논문집
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• 제22권2호
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• pp.81-86
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• 2019

Although the localization rate of shipbuilding and marine equipment goods is set to be 70 percent by 2020, but the localization rate of equipment and materials for shipbuilding and marine facilities is currently 10 to 30 percent. For Korea's Big 3 shipbuilders, which build 70 percent of the world's largest shipbuilders, localization of shipbuilding equipment and equipment is an essential factor. In particular, there is a growing need to localize equipment and materials in terms of the number of lead standards and A/S. It is expected that there will be a rapid expansion of LNG carriers in the future, and it is necessary to develop equipment and equipment materials of LNG ships. In this study, the design and manufacture of LNG vessel equipment was conducted. Design and basic performance tests of 4-inch QCDC for LNG bunkering were conducted.

• 신재생에너지
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• 제16권4호
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• pp.49-64
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• 2020

Photovoltaic and Thermal collector (PV/T) systems are renewable energy devices that can produce electricity and heat energy simultaneously using solar panels and heat exchangers. Since PV/T systems are exposed to the outdoors, their reliability is affected by various environmental factors. This paper presents a reliability test for a PV/T system and evaluates the test results. The reliability assessment entails performance, environment, safety, and life tests. The factor that had the greatest influence on the life of the system was the hydraulic pressure applied to the heat exchanger. A test was conducted by repeatedly applying pressure to the PV/T system, and a reliability analysis was conducted based on the test results. As a result, the shape parameter (β) value of 5.6658 and the B10life 308,577 cycles at the lower 95% confidence interval were obtained.

• 한국재료학회지
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• 제25권6호
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• pp.305-316
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• 2015

The study of grinding behavior characteristics on the metal powders has recently gained scientific interest due to their useful applications to enhance advanced nano materials and components. This could significantly improve the property of new mechatronics integrated materials and components. So, a new evaluation method for standardizing grinding equipment and a comparative study for the grinding experiment during the grinding process with various grinding mills were investigated. The series of grinding experiments were carried out by a traditional ball mill, stirred ball mill, and planetary ball mill with various experimental conditions. The relationship between the standardization of equipment and experimental results showed very significant conclusions. Furthermore, the comparative study on the grinding experiment, which investigated changes in particle size, particle morphology, and crystal structure of materials with changes in experimental conditions for grinding equipment, found that the value of particle size distribution is related to the various experimental conditions as a revolution speed of grinding mill and media size.