• Journal of the Korean Ceramic Society
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• v.27 no.8
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• pp.1020-1026
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• 1990

The effect of heating rate on the microstructural evolution during sintering of PZT ceramics has been investigated. In case of PZT powder compacts containing excess of PbO, fast heating caused incomplete rearrangement of solid grains in a liquid, resulting in lower density and inhomogeneous pore shape ; on contrary, slow heating resulted in better densification. In contrast, in case of compacts without excess PbO, the densification was enhanced by fast heating due to suppression of the grain growth.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1204-1212
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• 2024

To accurately calculate the heating distribution of the fast reactor, a neutron-photon library in MATXS format named Knight-B7.1-1968n × 94γ was processed based on the ENDF/B-VII.1 library for ultrafine groups. The neutron cross-section processing code MGGC2.0 was used to generate few-group neutron cross sections in ISOTXS format. Additionally, the self-developed photon cross-section processing code NGAMMA was utilized to generate photon libraries for neutron-photon coupled heating calculations, including photo-atom cross sections for the ISOTXS format, prompt photon production cross sections, and kinetic energy release in materials (KERMA) factors for neutrons and photons, and the self-shielding effect from the capture and fission cross sections of neutron to photon have been taken into account when the photon source generated by neutron is calculated. The interface code GSORCAL was developed to generate the photon source distribution and interface with the DIF3D code to calculate the neutron-photon coupling heating distribution of the fast reactor core. The neutron-photon coupled heating calculation route was verified using the ZPPR-9 benchmark and the RBEC-M benchmark, and the results of the coupled heating calculations were analyzed in comparison with those obtained from the Monte Carlo code MCNP. The calculations show that the library was accurately processed, and the results of the fast reactor neutron-photon coupled heating calculations agree well with those obtained from MCNP.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.67-71
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• 2009

This research is a new structure of the semiconductor substrate heating apparatus in which the assembly and expansion are possible. The fast thermo-responsive according to the direct heating structure of the heating plate layer adhering closely to the floor side of a substrate and the fast heat loss minimization can be accomplished. Moreover, the contact area of the sheath heater, which is the heating plate layer built-in heating apparatus, is increased, so that it has more heating valid area. There is no problem with the deformation interpreted in the state where it assembles the block of a several of the simulation result structure, the safety, and the stress. In addition, it is confirmed that building a large-size heating block is possible since the temperature deflection of the manufactured plate is lower than the standard value.

• Applied Chemistry for Engineering
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• v.18 no.4
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• pp.344-349
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• 2007

NaY zeolites synthesized by microwave heating were compared with those obtained by conventional heating. When the same temperature increasing rates were adopted in both heating methods, the microwave heating shortened the induction period and enhanced the rate of crystallization of NaY zeolites compared with the conventional heating. Irrespective of microwave radiation, the fast temperature increasing rate also shortened the induction time and enhanced the crystallization of NaY zeolites. The crystal sizes of NaY zeolites were large under the fast temperature raise of the reaction mixture and became larger by microwave radiation. At the same time, the fast temperature increasing rate has reduced the energy consumption due to the fast completion of reaction during the synthesis of NaY zeolite. The energy consumption in the conventional ethylene glycol bath was lower than that in the microwave oven with the same temperature increasing rate in this study, which means that the energy efficiency is not always high in microwave heating. If the temperature increasing rate is carefully controlled, however, NaY zeolite can be produced with high energy efficiency in the microwave oven.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.408-411
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• 2008

As to this research is new structure of the semiconductor substrate heating apparatus. The fast thermoresponsive according to the direct heating structure of the heating plate layer adhering closely to the floor side of a substrate and the fast heat loss minimization can be accomplished. Moreover, the contact area of the sheath heater, which is the heating plate layer built-in heating apparatus, is increased, so that it has more heating valid area. For this, it adheres closely to the substrate, in which the photosensitive film is coated and the heating plate layer, adhering closely to the floor side of a substrate the mica layer which adheres closely to the floor side of the upper heating plate layer in order to minimize an insulation and heat loss, and the lower part of the mica layer and it is comprised of the floor plate layer. The heating plate layer forms the continued groove portion over the floor side whole. The sheath heater for heating a substrate is inserted with the groove portion and the heating plate layer is comprised. It is confirmed that by using the new substrate heating structure, the temperature change of the heating plate against the time is observed. Then, there is the electric power saving effect of about 40% in comparison with the existing method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.43-44
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• 2015

In this study, spalling property were evaluated from concrete with compressive strengths of 30MPa, 90MPa, 180MPa, applied with fast heating condition(ISO-834 standard heating curve) and slow heatign condition(1℃/min). As a result, the spalling property of concrete was shown differently with compressive and heatign rate. And It could be separated three as non spalling, surface spalling and explosive spalling.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.558-562
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• 2005

Crystallization of SAPO-5 and SAPO-34 molecular sieves with microwave and conventional electric heating of the same gel has been investigated in an alkaline condition using N,N,N’N’tetraethylethylenediamine as a template molecule. SAPO-5 structure can be selectively prepared with microwave heating because of the fast crystallization of the technique. On the other hand, SAPO-34 is the sole product with usual conventional electric heating because SAPO-5 can be gradually transformed into SAPO-34 structure with an increase in crystallization time. This phase selectivity is probably because of the relative stability of the two phases at the reaction conditions (kinetic effect). Crystallization with microwave heating can be suggested as a phase selective synthesis method for relatively unstable materials because of fast crystallization.

• Carbon letters
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• v.15 no.1
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• pp.15-24
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• 2014

As a part of the electromagnetic spectrum, microwaves heat materials fast and efficiently via direct energy transfer, while conventional heating methods rely on conduction and convection. To date, the use of microwave heating in the research of carbon-based materials has been mainly limited to liquid solutions. However, more rapid and efficient heating is possible in electron-rich solid materials, because the target materials absorb the energy of microwaves effectively and exclusively. Carbon-based solid materials are suitable for microwave-heating due to the delocalized pi electrons from sp2-hybridized carbon networks. In this perspective review, research on the microwave heating of carbon-based solid materials is extensively investigated. This review includes basic theories of microwave heating, and applications in carbon nanotubes, graphite and other carbon-based materials. Finally, priority issues are discussed for the advanced use of microwave heating, which have been poorly understood so far: heating mechanism, temperature control, and penetration depth.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.39-42
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• 1989

The limitations of high-power electrical lasers due to heating of the gas and the instability of the glow discharge can be alleviated by the flow of the lasing medium. In order to achieve high power and efficient laser, we are developing a fast-axial flow CO2 laser. We describe here the classification of gas-discharge CO2 lasers according to the cooling methods of the lasing medium and the design features of the fast-axial flow CO2 laser.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.890-896
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• 2016

Paulownia tomentosa is one of fast-growing wood species in Korea. In order to evaluate the solid bioenergy properties of Paulownia tree, this study examined the heating value, moisture content (MC), pH and proximate analysis of stem, branch, root, bark and leaf. The heating values of wood parts were slightly higher than those of bark and leaf, and that of branch was the highest among all the samples. The higher moisture content of bark and leaf referred to their lower heating value. Also, the pH of stem, branch and root was similar and lower than those of bark and leaf. The ash content of bark and leaf was much higher than that of wood parts, which is the one of the reasons for effect on the lower heating value and higher pH. While, the volatile matter content (VMC) of bark and leaf was lower than those of wood parts. The bark showed the highest fixed carbon content (FCC), while the FCC of stem was the lowest among all the samples. The obtained results are encouraging that the Paulownia tree could be totally utilized as alternative fuels for bioenergy production.