• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.4
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• pp.59-66
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• 2012

This study is interested in identifying the effectiveness of alkali-activated fire protection material compounds including the alkali-activator such as potassium hydroxide, sodium silicate and fly ash as the fire resistant finishing materials. Also, this paper is concerned with change in compressive strength and pore structure of the alkali-activated fire protection material at high temperatures. The testing methods of fire protection materials in high temperature properties are make use of TG-DSC and mercury intrusion porosimetry measurements. This study results show that compressive strength is rapidly degraded depending on a rise of heating temperature. Porosity showed a tendency to increase irrespective of specimen types. This is due to both the outbreak of collapse of gel comprising the cement and a micro crack by heating. However, alkali-activated fire protection material composed of potassium hydroxide, sodium silicate and fly ash has the thermal stability of the slight decrease of compressive strength and porosity at high temperature. These thermal stability is caused by the ceramic binding capacity induced by alkali activation reaction by the reason of the thermal analysis result not showing the decomposition of calcium hydrate.

• Nuclear Engineering and Technology
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• v.15 no.3
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• pp.160-178
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• 1983

A method which determines TRIGA Mark-III core power distribution by measuring fuel temperature is developed. The temperature measurement is performed by sweeping the already existing instrumented fuel elements which are loaded as an expedient of safe operation, and the number of fuel positions swept is 16. Experimental results are compared with those from computation using neutron diffusion theory. The maximum and standard deviations are 12 and 5%, respectively. It is confirmed that the estimation of rod power density of measuring fuel temperature is for more convenient than the conventional methods, and that it is proved to be very accurate as well.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.1
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• pp.98-106
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• 1998

This paper shows the temperature distribution of double hull compartment and of cofferdam in a large LNG Carrier. In LNG Carrier, due to the lower cargo temperature($-163^{\circ}C$), structures are forced to lose their strength if additional heat is not supplied. So it is very important to estimate the temperature distribution and the heat flux needed to maintain the structure properly. The temperature of each compartment is obtained using 2-dimensional model analysis and compared with 3-dimensional results. And also this paper gives preliminary estimation of pipe length to supply necessary heat flux in bare pipe and finned pipe.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.6
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• pp.609-615
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• 2000

The energy conservation is one of the most important issues in recent years. Especially, the energy conservation through improved control strategies is one of the most highly possible area to be implemented in the near future. The energy conservation of the ice storage system can be accomplished through the improved control strategies. A real time building load prediction algorithm was developed. The expected highest and the lowest outdoor temperature of the next day were used to estimate the next day outdoor temperature profile. The measured dry bulb temperature and the measured building load were used to estimate system parameters by using the on-line weighted recursive least square method. The estimated hourly outdoor temperatures and the estimated hourly system parameters were used to predict the next day hourly building loads. In order to see the effectiveness of the building load prediction algorithm, two different types of building models were selected and analysed. The simulation results show less than 1% in error for the prediction of the next day building loads. Therefore, this algorithm may successfully be used for the development of improved control algorithms of the ice storage system.

• Journal of Hydrogen and New Energy
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• v.31 no.2
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• pp.184-193
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• 2020

One of the technical methods to increase the volumetric energy density of hydrogen is to pressurize the gaseous hydrogen and then contain it in a rigid vessel. Especially for automotive systems, the compressed hydrogen storage can be found in cars as well as at refueling stations. During the charging the pressurized hydrogen into a vessel, the temperature increases with the amount of stored hydrogen in the vessel. The temperature of the vessel should be controlled to be less than a limitation for ensure stability of material. Therefore, the accurate estimation of temperature is of significance for safely storing the hydrogen. In this work, three well-known cubic equations of state (EOSs) were adopted to examine the accuracy in regenerating thermodynamic properties of hydrogen within the temperature and pressure ranges for the compressed hydrogen storage. The formulations representing molar volume, internal energy, enthalpy, and entropy were derived for Redlich-Kwong (RK), Soave-Redlioch-Kwong (SRK), and Peng-Robinson (PR) EOSs. The calculated results using the EOSs were compared with literature data given by NIST. It was revealed that the accuracies of RK and SRK EOSs were satisfactorily compatible and better than the results by PR EOS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.13-19
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• 2013

This study examines thermal safety on three-way catalyst that dominates 70% among whole exhaust gas purification device in 2003. Three-way catalyst maintains high temperature in interior domain but maintains low temperature on outside surface. Therefore this device shows tensile stress on outside surface. Temperature distribution of three-way catalyst was acquired by thermal flow analysis for predicted thermal flow parameter. Thermal stress analysis for three-way catalysis was performed based on this temperature distribution. Thermal safety of three-way catalyst was estimated by strength reduction factor and failure probability.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.1
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• pp.19-30
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• 2001

This study was carried out to investigate the influences of environmental condition in storage room, moisture content and packing weight of leaf on the carbonization of processed flue-cured leaf tobacco, and find out a regression model able to pre-estimate the degree of carbonization. The influence of temperature and humidity in storage room on the carbonization was high,, while that of packing weight was relatively low, However, high moisture content and packing weight of leaf accelerated the carbonization under the high temperature and humidity condition. Thus the leaf tobacco under the condition of 4$0^{\circ}C$, 7$0^{\circ}C$ R.H. in storage room, 16% moisture content and 286 kg/box of packing weight could be carbonized within one month. The pH, total sugar content, lightness(L) and yellowness(b) of leaf were closely related to carbonization of leaf during storage. There were significant regression and yellowness of leaf. It is considered that the certification and/or pre-estimation of carbonization during storage may be possible by applying the regression equation.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.866-871
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• 2006

Recently according to the fashion of well-being, the case study of under floor heating system type for residential space is increasing. Specially double slab floor system can make several roles as reducing the acoustic noises and also supplying fresh air through the gap. So in present study floor heating performance was examined with various location of the space in the case of floor supply air and ceiling supply air. In both cases return air went out through ceiling opening. As one of the result is that when using the heat pipe type floor heating system the temperature difference between supply and return water was $15.2^{\circ}C$, but in case of commercial type floor heating system the temperature difference was $5.3^{\circ}C$ when the supply water temperature was $50^{\circ}C$.

• Journal of the Korean Solar Energy Society
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• v.30 no.4
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• pp.49-54
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• 2010

Most energy using in building part is mainly consumed for heating and cooling to meet occupancy's comfort temperature. Generally, heating energy consumption show high value than cooling energy in Korea because of high temperature difference in winter season as compared with summer in apartment building. The efforts to develope mechanical performance have been studied to reduce energy consumption in building energy field until now. However, the energy consumption in building is impacted by not only system performance but also PMV particularly at temperature and Clo value. This means that energy consumption can be changed by occupancy's comfort setting temperature in apartment building. This study investigated the passibility of overheating in apartment building by occupant' slow Clo and its setting temperature from preceding research and then the heating energy consumption by setting temperature was calculated with ESP-r. The effects of heating energy and $CO_2$ reduction are also evaluated quantitatively with Clo value. The results showed that keeping ISO-7730 standards can reduce heating energy up to 21% in compared with option 2; also, wearing underclothes with ISO-7730 standard can considerably reduce heating energy consumption up to 50%. As compared with option 2, the reduction of $CO_2$ emission for option 3 showed 0.63TCO2 of kerosene, 0.49TCO2 of LNG and 1.09TCO2 of electricity. The option 4 can be reduced by 1.48TCO2 of kerosene, 1.16TCO2 of LNG and 2.57TCO2 of electricity respectively.

• Tunnel and Underground Space
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• v.14 no.1
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• pp.16-25
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• 2004

As underground caverns have many advantages such as safety and operation, they can also be used for gas storage purpose. When liquefied gas is stored underground, the cryogenic temperature of the gas affects the stability of the storage cavern. In order to store the liquefied gas successfully, it is essential to estimate the exact temperature distribution of the rock mass around the caverns. The main purpose of this study is the development of theoretical solution to be able to estimate the temperature distribution around storage caverns and the assessment of the solution. In this study, a theoretical solution and a conceptual model for estimating two and three dimensional temperature distribution around the storage caverns are suggested. Based on the multi-dimensional transient heat transfer theory, the theoretical solution is successfully derived by assuming the caverns shape as simplified geometry. In order to assess the theoretical solution, by performing numerical experiments with this multi-dimensional model, the temperature distribution of the theoretical solution is compared with that of numerical analysis. Furthermore, the effects of the caverns size are investigated.