• Journal of Power System Engineering
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• v.20 no.5
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• pp.46-51
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• 2016

The TMCP steel has expanded in the marine structure during manufacturing process because of its excellent weld-ability and impact toughness. In the case of merchant ships, coverage of TMCP steel has been used widely on over DH36 Classifications material. The line heating process is applied to the outer surface of the steel plate for the shipbuilding. In this study, We compared between TMCP and normalizing steel for shipbuilding by analyzing some basic data through performing the natural cooling after the line heating. The experimental results show the angular misalignment changes in line heating. Heated surface of normalizing steel material expanded to $-0.3^{\circ}$ and reduced to $+0.2^{\circ}$ after cooling. And during cooling at $194^{\circ}C$ for 1,500 seconds, Angular Misalignment began from - direction to + direction, passed the critical point to the default at 2,200 seconds and did not take place any more at $103^{\circ}C$ after the 2,700 seconds. Angular Misalignment results of TMCP steels and Normalizing steel material show same angular misalignment lasted 1,200 seconds, TMCP steel has given more expansion and contraction angle which is $0.2^{\circ}$ than that of the Normalizing steel. Length difference between expansion and contraction is about 0.3 mm.

• Journal of Biosystems Engineering
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• v.19 no.3
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• pp.211-221
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• 1994

In this study, to maximize the solar energy utilization for greenhouse heating during the winter season, solar energy-underground latent heat storage system was constructed, and the thermal performance of the system has been analyzed to obtain the basic data for realization of greenhouse solar heating system. The results are summarized as follows. 1. $Na_2SO_4{\cdot}10H_20$ was selected as a latent heat storage material, its physical properties were stabilized and the phase change temperature was controlled at $13{\sim}15^{\circ}C$. 2. Solar radiation of winter season was the lowest value in December, and Jinju area was the highest and the lowest value was shown in Jeju area. 3. The minimum inner air temperature of greenhouse with latent heat storage system(LHSS) was $7.0{\sim}7.5^{\circ}C$ higher than that of greenhouse without LHSS and was $7.0{\sim}11.2^{\circ}C$ higher than the minimum ambient air temperature. 4. Greenhouse heating effect of latent heat storage system was getting higher according to the increase of solar radiation and was not concerned with the variation of minimum ambient air temperature. 5. The relative humidity of greenhouse with latent heat storage system was varied from 50 to 85%, but that of greenhouse without LHSS was varied from 30 to 93%. 6. The heating cost of greenhouse with solar energy-latent heat storage system was about 24% of that with the kerosene heating system.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.469-478
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• 2022

Tritium was extracted from tritium-contaminated aluminum samples by heating it in a high-temperature furnace at 200, 300, or 400 ℃ for 15 h. The extracted tritium was analyzed by using a liquid scintillation counter (LSC); the sample thicknesses were 0.4 and 2 mm. The differences in tritium extraction over time were also investigated by cutting aluminum stick samples into several pieces (1, 5, 10, and 15) with the same thickness, and subsequently heating them. The results revealed that there are most of the hydrated material based on tritium on the surface of aluminum. When the temperature was increased from 200 or 300 ℃-400 ℃, there are no large differences in the heating duration required for the radioactivity concentration to be lower than the MDA value. Additionally, at the same thickness, because the surface of aluminum is only contaminated to tritiated water, cutting the aluminum samples into several pieces (5, 10, and 15) did not have a substantial effect on the tritium extraction fraction at any of the applied heating temperatures (200, 300, or 400 ℃). The proportion of each tritium-release materials (aluminum hydrate based on tritium) were investigated via diverse analyses (LSC, XRD, and SEM-EDS).

• Transactions on Electrical and Electronic Materials
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• v.13 no.4
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• pp.181-184
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• 2012

$BaTiO_3$ based multilayer ceramic capacitors with Ni electrodes can be explained as 2-2 composites with different thermal expansion coefficient and sintering behaviors. To achieve the high capacitance and reliability of MLCCs, a homogenous Ni electrode configuration with high connectivity is required. We controlled the heating rates during sintering to achieve densification by suppressing grain growth. Experimental results revealed that a large heating rate gave high connectivity of Ni electrode, high capacitance, small dissipation factor, high breakdown voltage, and high reliability of MLCC chips.

• Steel and Composite Structures
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• v.9 no.3
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• pp.209-221
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• 2009

Heating correction, through heating and flattening a structure with a pressing machine, is the in-situ method used to repair buckled steel structures. The primary purpose of this investigation is to develop an FEM model which can predict the mechanical response of heat-corrected plates accurately. Our model clarifies several unsolved problems. In previous research, the location of the imperfection was limited to the center of the specimen although the mechanical behavior is strongly affected by the location of the imperfection. Our research clarifies the relationship between the location of the imperfection and the mechanical behavior. In addition, we propose further reinforcement methods and validate their effectiveness. Our research concludes that the strength of a buckled specimen can be recovered by heating correction and the use of an adequate stiffener.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1256-1259
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• 2006

The purpose of this study was to investigate the current status and influence factor in measuring the dynamic stiffness of damping materials. The property of the dynamic stiffness of damping materials was tested and analysed in condition such as the size of test samples and the change of relative humidity in heating chamber. Test results showed that the dynamic stiffness of after-heating was lower than that of before-heating in most samples and the change of relative humidity in heating chamber got little influence of the dynamic stiffness. The resonant frequency of test sample decreased $2{\sim}7Hz$ as the decrease of the size of sample. Because it was increased that total mass per unit area of sample, the change of dynamic stiffness had little influence.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.05a
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• pp.213-222
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• 1995

Korean traditional Ondol with the sensible heat storage medium has been for a long time used as residential heating system, in these days the concrete Ondol without the heat storage medium was realized as the heating system in the private houses and the apartments. This floor heating system is good for our health. But the concrete Ondol is not desirable for the energy saving and for the maintenance of comfortable room temperature because the heat storage medium is not employed in the concrete Ondol. And as the hot water circulating pipes ate buried under the the concrete floor, the concrete Ondol system has some kind of problems to be improved. Therefore the new type of Ondol system was developed in this study. And the new Ondol was consisted of latent heat storage material as heat storage medium with a great heat capacity and bioceramics as medium to maintain comfortable room temperature. In this study, the heat transfer characteristics of latent heat storage-bioceramic Ondol was analyzed theoretically.

• Korean Journal of Materials Research
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• v.6 no.6
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• pp.576-584
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• 1996

The zirconia-alumina composite, a low loss material, was sucessfully sintered using a 2.45 GHz microwave radiation. The dense zirconia was used as a microware coupling aid. The effect of microwave power level on the heating rates of samples and the feasibility of microwave energy use in processign ceramec materials were obtained. It was also obtained how to accurately measure the temperature. According to the microwave heating theory, heating mechanisms were discussed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.111-114
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• 2011

Waterprooping Method with sheet need to study technology and multilateral verification considering the arctic conditions as low temperature and humidity, which is the result only considered of material aspects without environmental condition in construction But there are no measures up until now. To solve this problem by using high frequency induction heating method developed waterproof sheets, cold (5 ℃ or less) can be applied in a more stable environment, water-resistant materials and construction methods were studied for development. The results of the test showed that high frequency induction heating method is effective for usability in low temperature condition and securement of proper quality than existing Waterprooping Method with sheet need.

• Electrical & Electronic Materials
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• v.1 no.1
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• pp.26-34
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• 1988

Sintered CdS/CdTe solar cells have been farbricated by coating a (Cd+Te) slurry on sintered CdS films followed by the sintering at 625.deg.C for one hour with various heating rates. When cadmium and tellurinm powders are used instead of CdTe powder to form CdS/CdTe junction, CdTe is formed in the temperature range of 290.deg.C-400.deg.C. The microstructure of the CdTe films depends strongly on the heating rate of the sintering due to the low melting temperature and the high vapor pressure of the elemental Cd and Te. An optimum heating rate obtain CdTe films with uniform and dense microstructure which, in turn, improves the efficiency of the sintered CdS/CdTe solar cells. All-polycrystalline CdS/CdTe solar cells with an efficiency of 9.57% under 50mW/cm$^{2}$ tungsten light have been farbricated by using a heating rate of 14.deg.C/min.