• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.1-9
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• 2007

Compressed natural gas (CNG) has been used as a vehicular fuel compressed at 24.8 MPa because the energy density of natural gas is extremely low compared with gasoline. Thus it has problems in both safety and cost for multiple stage compression. For these reasons the use of adsorbed natural gas (ANG) has been pursued since the storage of natural gas is possible at a relatively low pressure. The present target is to obtain media to store natural gas at 3.5 MPa as ANG that ensures the comparable energy density of CNG, giving approximately one-fourth the driving range of an equivalent volume gasoline tank. In this review, the recent development of carbon media, their characteristics, and practical applications for natural gas storage are introduced and some recommendations are also suggested.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1660-1668
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• 2017

The flow of liquids submerged with nanoparticles is of significance to industrial applications, specifically in nuclear reactors and the cooling of nuclear systems to improve energy efficiency. The application of nanofluids in water-cooled nuclear systems can result in a significant improvement of their economic performance and/or safety margins. Therefore, in this paper, Marangoni thermal convective boundary layer dusty nanoliquid flow across a flat surface in the presence of solar radiation is studied. A two phase dusty liquid model is considered. Unlike classical temperature-dependent heat source effects, an exponential space-dependent heat source aspect is considered. Stretching variables are utilized to transform the prevailing partial differential system into a nonlinear ordinary differential system, which is then solved numerically via the Runge-Kutta-Fehlberg approach coupled with a shooting technique. The roles of physical parameters are focused in momentum and heat transport distributions. Graphical illustrations are also used to consider local and average Nusselt numbers. We examined the results under both linear and quadratic variation of the surface temperature. Our simulations established that the impact of Marangoni flow is useful for an enhancement of the heat transfer rate.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1142-1153
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• 2019

This paper presents the effect of fusion procedure on the fusion performance of the thermal butt fusion in the safety class III buried HDPE piping per various tests performed, including high speed tensile impact, free bend, blunt notched tensile, notched creep, and PENT tests. The suitability of fusion joints and qualification procedures was evaluated by comparing test results from the base material and buttfusion joints. From the notched tensile test result, it was found that the fused joints have much lower toughness than the base material. It was also identified that the notched tensile test is more desirable than the high speed tensile impact and free bend tests presented in the ASME Code Case N-755-3 as a fusion qualification test method. In addition, with regard to the single low-pressure fusion joint performances, the procedure given by the ISO 21307 was determined to be better that the one specified in the Code Case N-755-3.

• International Journal of Advanced Culture Technology
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• v.7 no.3
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• pp.143-148
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• 2019

In order to solve the urban problems caused by the increase of the urban population, the construction of smart city applying the latest technology is being carried out all over the world. In particular, we will create a smart city platform that utilizes data generated in the city to collect and store and analyze, thereby enhancing the city's continuous competitiveness and resilience and enhancing the quality of life of citizens. However, existing smart city platforms are not enough to construct a platform for smart city as a platform for solution elements such as IoT platform, big data platform, and AI platform. To complement this, we will reanalyze the existing overseas smart city platform and IoT platform in a comprehensive manner, combine the technical elements applied to it, and apply it to the future Korean smart city platform. This paper aims to investigate the trends of smart city platforms used in domestic and foreign countries and analyze the technology applied to smart city to study smart city platforms that solve various problems of the city such as environment, energy, safety, traffic, environment.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.3
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• pp.353-364
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• 2019

The walk-way means a passage installed on the deck of a ship so that a person can safely move under any circumstances. So, the walk-way has to maintain a temperature of $5^{\circ}C$ or more for anti/de-icing even at an ambient temperature of $-62^{\circ}C$, a temperature in polar region. At present, the walk-way with heating cable is used, but the anti/de-icing effect is insufficient due to low heat transfer efficiency. Also, it has a construction problem due to heavy weight. In this study, an walk-way with a CNT surface heating element is proposed for the high anti/de-icing effect and the heating value per unit volume. The international standard survey, conceptual design, and simulation for the structural safety and the heat transfer are performed for the development of the proposed walk-way. To enhance the performance, the case studies based on the simulation analysis are conducted. Finally, the final prototype, applying the optimum material and thickness (3.2t of SS400) based on the case study results, is fabricated and experimented.

• Design & Manufacturing
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• v.17 no.2
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• pp.47-54
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• 2023

The research direction of the automobile industry worldwide is speeding up research to improve fuel efficiency through weight reduction as the weight of automobiles increases due to environmental problems, convenience demands, and safety problems. As a way to solve weight reduction, there is a method of improving mechanical properties by improving the development and manufacturing method of lightweight materials with replaceable mechanical properties. Therefore, research on the molding and processing technology of aluminum, which is a lightweight material, is being actively conducted. In this study, aluminum material was applied. By using Autoform S/W, a press forming analysis program, the blank holding force, mold die R, and bead restraint force were selected in three levels, respectively, and the results and optimization of formability and shape freezing were carried out. In this study, aluminum material was applied. By using Autoform S/W, a press molding analysis program, the blank holding force, mold die R, and bead restraint force were selected in three levels, respectively, and the results and optimization of formability and shape freezing were carried out. The optimized results were confirmed by comparative analysis of formability and Spring Back. As a result of the experiment, it was possible to confirm the result value of the Spring Back of the final product according to the tensile change of the material.

• Korean Journal of Materials Research
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• v.33 no.10
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• pp.385-392
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• 2023

A solution combustion process for the synthesis of hollandite (BaAl₂Ti₆O₁₆) powders is described. SYNROC (synthetic rock) consists of four main titanate phases: perovskite, zirconolite, hollandite and rutile. Hollandite is one of the crystalline host matrices used for the disposal of high-level radioactive wastes because it immobilizes Sr and Lns elements by forming solid solutions. The solution combustion synthesis, which is a self-sustaining oxi-reduction reaction between a nitrate and organic fuel, generates an exothermic reaction and that heat converts the precursors into their corresponding oxide products in air. The process has high energy efficiency, fast heating rates, short reaction times, and high compositional homogeneity. To confirm the combustion synthesis reaction, FT-IR analysis was conducted using glycine with a carboxyl group and an amine as fuel to observe its bonding with metal element in the nitrate. TG-DTA, X-ray diffraction analysis, SEM and EDS were performed to confirm the formed phases and morphology. Powders with an uncontrolled shape were obtained through a general oxide-route process, confirming hollandite powders with micro-sized soft agglomerates consisting of nano-sized primary particles can be prepared using these methods.

• Advances in nano research
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• v.16 no.4
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• pp.365-374
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• 2024

This study delves into the significant impact of integrating nanomaterials, specifically carbon and graphene nanoparticles, into the polymer matrix of aluminum alloy 356, utilizing the vortex casting technique, with the aim of improving the mechanical properties of table tennis equipment. Athletes and their coaching teams have long been on a quest for high-performance sports gear, recognizing its pivotal role in unlocking the full potential of players. The dedication of engineers to craft designs, select materials with precision, and uphold stringent testing standards reflects the commitment to meeting the demands of the sporting world. Yet, to remain at the forefront, sports engineering must continually align with contemporary technologies, and nanotechnology has emerged as a transformative force in this regard. This study not only underscores the meticulous efforts in material integration but also highlights the remarkable strides made possible by nanotechnology. Aluminum nanocomposites, particularly, showcase a groundbreaking fusion of exceptional strength and reduced weight, marking a notable achievement in sports equipment innovation. The research outcomes are compelling, revealing a substantial enhancement in the mechanical performance of the sports structures under scrutiny. This promising development hints at a potential paradigm shift in the manufacturing of sports equipment, promising a new era of elevated athlete performance and enhanced safety during the rigors of physical education training. This study stands as a testament to the tangible impact of nanotechnology on the ever-evolving landscape of sports equipment.

• Journal of Life Science
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• v.28 no.5
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• pp.605-614
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• 2018

Bee pollen has an outer wall which is resistant to both acidic and basic solutions and even the digestive enzymes in the gastrointestinal tract. Therefore, the oral bioavailability of bee pollen is only 10-15%. A previous study reported on wet-grinding technology which increased the extraction of active ingredients from bee pollen by 11 times. This study was designed to investigate the safety of wet-ground bee pollen. First, a single dose of wet-ground bee pollen was tested in both rats and beagle dogs at dosages of 5, 10, and 20 g/kg and 1.5, 3, and 6 g/kg, respectively. In rats, compound-colored stools were found in those administered 10 g/kg or more of wet-ground bee pollen. In beagle dogs, 6 g/kg of wet-ground bee pollen induced diarrhea in one male for four hours. However, no obvious clinical signs were found through the end of the experiment in rats and beagle dogs. In addition, no histological abnormality was found in all animals. The data indicates that a single dose of up to 20 g/kg of wet-ground bee pollen is safe. Next, the genetic toxicity of nano-sized bee pollen was tested. This study employed a bacterial reverse mutation test, a micronucleus assay, and a chromosomal aberration assay. In the micronucleus assay, there was no genetic toxicity up to the dosage of 2 g/kg. There was also no genetic toxicity in the bacterial reverse mutation test and chromosomal aberration assay. This data provides important information in developing nano-sized bee pollen into more advanced functional foods and herbal medicines.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.3
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• pp.247-256
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• 2011

Existing organic UV protection materials seem to be problematic due to their penetration and irritation to skin. Inorganic UV protection materials are also at issue for safety of their nano-type transformation. Therefore, the recent studies of UV protection materials have been focused not only on the effectiveness but also on their safety. One of the UV protection materials in study which have higher safety is the organic-inorganic conjugation type UV protection material. Previously, we have reported the manufacturing process, physical property and UV protection efficiency of methoxychinnamidoprophy poloysilsesquixan as a new cross-linked polymer type UV protection material. In this study, we have evaluated the effect of the methoxychinnamidoprophy poloysilsesquixan on embryo-fetal development in SD rats. This study is expected to show some definite information related to the effect on pregnancy or embryo-fetal abnormality in case of the clinical exposure of the methoxychinnamidoprophy poloysilsesquixan.