• Journal of the Korean Wood Science and Technology
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• v.45 no.2
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• pp.147-158
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• 2017

Among the energy consumption in building, the heating energy takes the largest part. Therefore, it is important to minimize the heat energy loss in building for the reduction of overall energy use in construction. The most important points for the minimization of energy loss in building are insulation and airtightness. Especially, in wood houses, airtightness is very important for energy saving as well as increase of durability. However, the researches on airtightness of wood buildings have been started recently and are very deficient especially in Korea. In this study, air leakage properties and airtightness performance were evaluated for light-frame wood houses built in Daejeon and Chungnam area. Total 7 houses were evaluated, among which four houses (Case 1 to Case 4) were in the construction stage before interior finish and the other three houses (Case 5 to Case 7) were after completion of construction work. The tests for airtightness were conducted by pressurization-depressurization method, and the factors included in the measurements includes air leakage rate at 50 Pa (CMH50), air change rate at 50 Pa (ACH50), equivalent leakage area (EqLA) and EqLA per floor area. As a result of this study, key air leakage points in wood houses were found to be the gaps between floor and wall, the holes for wiring and plumbing, the double glasses windows and the entrance doors. The average value of ACH50 for the houses after completion of construction work was $3.5h^{-1}$ that was similar to Europe standard ($3.0h^{-1}$). ACH50 was proportional to EqLA per floor area but inversely proportional to the internal volume, the net floor area and the area of window.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.551-557
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• 2024

Hydrogen is a renewable energy source with various characteristics such as clean, carbon-free and high-energy, and is internationally recognized as a "future energy". With the rapid development of the hydrogen energy industry, more hydrogen infrastructure is needed to meet the demand for hydrogen. However, hydrogen infrastructure accidents have been occurring frequently, hindering the development of the hydrogen industry. HyRAM+, developed by Sandia National Laboratories, is a software toolkit that integrates data and methods related to hydrogen safety assessments for various storage applications, including hydrogen refueling stations. HyRAM+'s physics mode simulates hydrogen leak results depending on the hydrogen refueling station components, graphing gas plume dispersion, jet frame temperature and trajectory, and radiative heat flux. In this paper, hydrogen leakage data was extracted from a hydrogen refueling station in Samcheok, Gangwon-do, using HyRAM+ software. A hydrogen leakage simulator was developed using data extracted from HyRAM+. It was implemented as a dashboard that shows the data generated by the simulator using a database and Grafana.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.683-690
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• 1996

The MIDLOOP code has been developed for the evaluation of RES pressurization transients initiated from a loss-of-Residual Heat Removal System (RHRS) during mid-loop operation after reactor shutdown. It provides a fast running and realistic tool for studying parametrically the response of important plant parameters such as pressure, temperature, and level to various plant combinations of the primary side vent, makeup, and leakage procedures and the steam generator (SG) conditions. The code consists of ten nodes representing the primary and secondary sides of a nuclear power plant and can analyze the effect of air on the primary system pressurization and primary to secondary heat transfer. The analysis results of the MIDLOOP code are in good agreement with the ROSA-IV/LSTF experiment without opening in the RCS.

• Tribology and Lubricants
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• v.12 no.3
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• pp.79-84
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• 1996

One of the greatest dangers in mechanical face seals is the formation of heat checking and thermal stress cracks on the sliding surfaces. These thermal distortions due to non-uniform heating lead to increase the leakage of the sealed fluids and wear, and with balance of the seal can cause the seal faces to part. In this study heat checking and thermal stress cracks are investigated experimentally. These thermal distortions are explained using the thermal models of the conatct geometries between the seal ring and the seal seat. To overcome these thermal problems, the thermohydrodynamic seal is presented. The newly developed mechanical seal may substantially reduce the friction torque, frictional heating which causes heat checking and thermal stress cracks, and wear.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.425-428
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• 2006

The bigger of concrete strctures by a construct technique improvement, and the increase of the cement quantity which is caused by with use of the high-strength concrete for the load-carrying-capacity and a durability cause temperature cracks by a heat of hydration. The temperature crack due to the heat of hydration classified a nonstructural crack. but it has a bad effect on durability of concrete structures. especially, in case of a subway concrete box structure, when a water-proof facilities is beaked on an outer-wall, the water leakage occurs through a penetration crack generated from a wall of the concrete structure too. This paper, for the subway concrete box strucuture, the use of blended cement, the temperature of air and concrete, control joint, was considered and analysed by a three dimensional finite element method.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.517-520
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• 2006

The waterproofing of Building on the roof has been exposed more underground or the other part of waterproofing than environmental factor(solar heat, UV, salt, acid rain, wind, temperature, snow, rain, etc.) or physical factor. So it must be have a waterproofing performance and it has a special technique for the maintaining of concrete durability. Therefore, exposed waterproof layer has to protected from UV, solar heat, rain and the outside environment also, to endurance durability methods spread face plate topcoat material on the waterproof layer. But, actuality faceplate waterproof layer of topcoat materials are unbearable to UV, solar heat and moisture etc. and it doesn't have adhesion with waterproof layer in the middle. So it happens to crack, separating and heaving etc. Therefore, in the study, we will suggest that using of the exposed roof waterproof layer topcoat materials test method manage rooftop waterproof layer for the durability and the stability.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.581-584
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• 2007

The subway concrete box structure can`t establish expansion joint because of animal power delivery of the subway rail. In this case, As increase of structure volume, it is subjected to cause temperature crack. The temperature crack due to the heat of hydration classified a nonstructural crack. but it has a bad effect on durability of concrete structures. especially, in case of a subway concrete box structure, when a water-proof facilities is beaked on an outer-wall, the water leakage occurs through a penetration crack generated from a wall of the concrete structure too. This paper, for the subway concrete box structure, examined a condition of temperature crack occurrence by a heat of hydration concerned external temperature from analysing by a three dimensional finite element method.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.705-708
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• 2006

The bigger of concrete structures by a construct technique improvement, and the increase of the cement quantity which is caused by with use of the high-strength concrete for the load-carrying-capacity and a durability cause temperature cracks by a heat of hydration. The temperature crack due to the heat of hydration classified a nonstructural crack. but it has a bad effect on durability of concrete structures. especially, in case of a subway concrete box structure, when a water-proof facilities is beaked on an outer-wall, the water leakage occurs through a penetration crack generated from a wall of the concrete structure too. This paper, for the subway concrete box structure, which is located in chloride attack region, the use of blended cement, the temperature of air and concrete, was considered and analysed by a three dimensional finite element method.

• Transactions on Electrical and Electronic Materials
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• v.17 no.1
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• pp.21-24
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• 2016

A junction box used in a 3 kW photovoltaic power generation system plays a role in collecting and supplying the direct current voltage produced by photovoltaic modules to an inverter. It is also used for facilitating maintenance checks and protecting the module and inverter by keeping the voltage constant. As for the junction box, using it in a parallel connection creates a difference between the setup modules. In order to compensate, an inverse voltage diode is used. But the high-power created through the solar generator can be delivered to the inverter through the inverter regularly. Therefore, a component can break down due to excess heat. And consequently short circuits and electric leakage occurs. In this study, using a junction box that enabled the bypass of high electric power, it was possible to reduce heat generation by approximately 35℃ when compared to a standard junction box.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.307-312
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• 2022

A hair essence containing α-tocopheryl acetate, retinyl palmitate, and phytantriol (TRP-hair essence) was prepared. TRP-hair essence was excellent in thermal stability to the extent that it did not harden at all even at 210 ℃. TRP-hair essence potently protected the hair from heat stress, significantly reducing the protein leakage in heat-treated hair (p <0.001). Treatment of TRP-hair essence to dyed human hair significantly protected hair against heat stress (p <0.05) as well as improved hair cuticle and color persistence (p <0.05). In addition, as a result of directly treating human hair with TRP-hair essence, the cuticle and tensile strength of human hair were significantly improved (p <0.05). These results suggest that TRP-hair essence can be effective for hair protection and hair quality improvement.