• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.514-519
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• 2001

Converter has been slag produced 10 million tons per year in Japan. It is a steel making by product produced in the same way as the blast-furnace slag. Though blast-furnace slag is being used effectively as a concrete admixture, the converter stag has never been used effectively because of the expansion action of contained free lime and iron oxide. This is an important environmental problem in the steel industry. Beta-2CaOSiO$_2$(beta-C$_2$S) is contained 40 percent in converter slag, therefore it is very promising as a concrete admixture. We proposed an accelerated aging processes capable of stabilizing the converter slag in a short time. The converter slag is dipped into alkali aqueous solution after heating at low temperature. It was subsequently ground to a grain size of 75 ${\mu}{\textrm}{m}$ , inner 30 percent of OPC. The properties of mortar and concrete using the blended cement were determined. As a result, it has become apparent that the expansion was reduced and long term compressive strength was increased while that at early ages was not so remarkable. The hydration exotherm rate was lower than that of the OPC.

• Macromolecular Research
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• v.15 no.7
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• pp.662-670
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• 2007

The crystallization behavior and fine structure of poly(ethylene terephthalate) (PET)/A-zeolite nanocomposites were assessed via differential scanning calorimetry (DSC) and time-resolved small-angle X-ray scattering (TR-SAXS). The Avrami exponent increased from 3.5 to approximately 4.5 with increasing A-zeolite contents, thereby indicating a change in crystal growth formation. The rate constant, k, evidenced an increasing trend with increases in A-zeolite contents. The SAXS data revealed morphological changes occurring during isothermal crystallization. As the zeolite content increased, the long period and amorphous region size also increased. It has been suggested that, since PET molecules passed through the zeolite pores, some of them are rejected into the amorphous region, thereby resulting in increased amorphous region size and increased long period, respectively. In addition, as PET chains piercing into A-zeolite pores cannot precipitate perfect crystal folding, imperfect crystals begin to melt at an earlier temperature, as was revealed by the SAXS profiles obtained during heating. However, the spherulite size was reduced with increasing nanofiller content, because impingement between adjacent spherulites in the nanocomposite occurs earlier than that of homo PET, due to the increase in nucleating sites.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3898-3906
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• 2023

The paper notes that the most common way of handling spent nuclear fuel (SNF) of power reactors is its temporary long-term dry storage. At the same time, the operation of the dry spent fuel storage facilities almost never use the modern capabilities of information systems in safety control and collecting information for the next studies under implementation of aging management programs. The author proposes a structure of an information system that can be implemented in a dry spent fuel storage facility with ventilated storage containers. To control the thermal component of spent fuel storage safety, a database structure has been developed, which contains 5 tables. An algorithm for monitoring the thermal state of spent fuel was created for the proposed information system, which is based on the comparison of measured and forecast values of the safety criterion, in which the level of heating the ventilation air temperature was chosen. Predictive values of the safety criterion are obtained on the basis of previously published studies. The proposed algorithm is an implementation of the information function of the system. The proposed information system can be used for effective thermal monitoring and collecting information for the next studies under the implementation of aging management programs for spent fuel storage equipment, permanent control of spent fuel storage safety, staff training, etc.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.3
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• pp.172-180
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• 2003

The purpose of this study is to observe the heat transfer process in in-vivo human muscle based on Proton Resonance Frequency(PRF) method in Magnetic Resonance Imaging(MRI). MRI was obtained to measure the temperature variation according to the heat transfer in phantom and in-vivo human calf muscle. A phantom(2% agarose gel) was used in this experiment. MR temperature measurement was compared with the direct temperature measurement using a T-type thermocouple. After heating agarose gel to more than 5$0^{\circ}C$ in boiling hot water, raw data were acquired every 3 minutes during one hour cooling period for a phantom case. For human study heat was forced to deliver into volunteer's calf muscle using hot pack. Reference data were once acquired before a hot pack emits heat and raw data were acquired every 2 minutes during 30minutes. Acquired raw data were reconstructed to phase-difference images with reference image to observe the temperature change. Phase-difference of the phantom was linearly proportional to the temperature change in the range of 34.2$^{\circ}C$ and 50.2$^{\circ}C$. Temperature resolution was 0.0457 radian /$^{\circ}C$(0.0038 ppm/$^{\circ}C$) in phantom case. In vivo-case, mean phase-difference in near region from the hot pack is smaller than that in far region. Different temperature distribution was observed in proportion to a distance from heat source.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.206-210
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• 1984

Heat penetration pattern of canned oyster mushroom(Pleurotus astreatus) was monitored for processing variables-can size, heating temperature and solid fill fraction, and its effects on sterilization condition was reviewed. The $f_h$ value decreased sharply with decrease of solid fill fraction and then became stable from certain solid fill fraction unique to can size. Heat penetration was a little faster at higher heating temperature with lower $f_h$ value. As viewed from $f_h$ value, convection started at higher solid fill fraction with higher length/diameter ratio, and $f_h$ values decreased to about 1.0 with decrease of solid fill fraction. From standpoint of overall cost, retorting time and energy consumption, solid fill fraction of 3/5 was optimum for all can sizes considered.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.243-247
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• 2014

Spherical NiO-YSZ particles were synthesized by ultrasonic spray pyrolysis (USP). The morphology of the synthesized particles can be modified by controlling parameters such as precursor pH, carrier-gas flow-rate, and temperature of the heating zone. The synthesized spherical NiO-YSZ particles have rough surface morphology at high carrier-gas flow-rates due to rapid gas exhaustion and insufficient particle ordering. The Ni-YSZ cermet anode synthesized by ultrasonic spray pyrolysis at a flow rate of l L/min, with precursor solution at pH4, showed a higher maximum power density of 256 $mW/cm^2$ compared to a conventionally mixed Ni-YSZ anode (185 $mW/cm^2$) at $800^{\circ}C$. While the area-specific resistance of conventionally mixed Ni-YSZ anodes increases gradually with operation time (indicating performance degradation), the Ni-YSZ anode synthesized by USP does not exhibit any performance degradation, even after 500 h.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.350-359
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• 2016

We performed fast pyrolysis of empty fruit bunch (EFB) in the range of temperature from $400{\sim}550^{\circ}C$ and 1.3 s of residence time. The effect of temperature on the yields and physicochemical properties of pyrolytic products were also studied. Elemental and component analysis of EFB showed that the large amount of potassium (ca. 8400 ppm) presents in the feedstock. Thermogravimetric analysis suggested that the potassium in the feedstock catalyzed degradation of cellulose. The yield of bio-oil increased with increasing temperature in the range of temperature from $400{\sim}500^{\circ}C$, while that of gas and biochar decreased and showed monotonous change each with increasing temperature. When the EFB was pyrolyzed at $550^{\circ}C$, the yield of bio-oil and char decreased while that of gas increased. Water content of the bio-oils obtained at different temperatures was 20~30% and their total acid number were less than 100 mg KOH/g oil. Viscosity of the bio-oils was 11 cSt (centistoke), and heating value varied from 15 to 17 MJ/kg. Using GC/MS analysis, 27 chemical compounds which were classified into two groups (cellulose-derived and lignin-derived) were identified. Remarkably the concentration of phenol was approximately 25% based on entire chemical compounds.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.42-49
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• 2004

Analytical solutions are developed to predict temperature of a satellite box during launch stage under the assumption of worst hot condition. The considered time period is from fairing jettison to separation of satellite during launch stage. After fairing jettison, a box mounted on outer surface of satellite are exposed to space environments such as direct solar flux, Earth IR, Albedo, and free molecular heating. The thermal governing equation is simplified to 1st order ordinary differential equation such that analytic solutions are acquired after the box is assumed as a single lumped mass. The analytical solutions are also available for mass varying box. Finally, the practical application is performed for the case of STSAT-1 launch scenario.

• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.669-674
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• 2002

Ni-Zn ferrite was sintered by microwave hybrid sintering method using microwave energy of 2.45 GHz, 700 W in the temperature range of 900$^{\circ}C$ ∼ 1070$^{\circ}C$. A high density (98%TD) Ni-Zn ferrite, added Bi$_2$O$_3$ and CuO, with a single phase was obtained by microwave sintering at 970$^{\circ}C$ for 15 min. All the sintered samples showed sintered density over 90% of TD. These results indicate that the processing time and energy consumption can be reduced significantly by microwave hybrid sintering method.

• Journal of Environmental Science International
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• v.24 no.6
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• pp.819-826
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• 2015

This study measured temperatures and albedos of urban surfaces for different colors and materials during summer, and calculated the energy budget over different urban surfaces to find out the thermal performance affecting the heat built-up. The study selected six surface colors and 13 materials common in urban landscape. Their surface temperatures (Ts) and albedos were measured at a given time interval in the daytime from June to August. Average Ts over summer season for asphalt-colored brick was $4.0^{\circ}C$ higher than that for light red-colored one and $9.7^{\circ}C$ higher than that for white-colored one. The Ts for artificial surface materials of asphalt paving, brown brick wall, and green concrete wall was $6.0^{\circ}C$ higher than that for natural and semi-natural ones of grass, grassy block, and planted concrete wall. There was the greatest difference of $16.3^{\circ}C$ at midafternoon in the Ts between asphalt paving and planted concrete wall. Average albedo over summer season of surface materials ranged from 0.08 for asphalt paving to 0.67 for white concrete wall. This difference in the albedo was associated with a maximum of $15.7^{\circ}C$ difference at midafternoon in the Ts. Increasing the albedo by 0.1 (from 0.22 to 0.32) reduced the Ts by about $1.3^{\circ}C$. Average storage heat at midday by natural and semi-natural surfaces of grass and grassy block was about 10% lower than that by artificial ones of asphalt, light-red brick, and concrete. Reflected radiation, which ultimately contributes to heating the urban atmosphere, was 3.7 times greater for light-red brick and concrete surfaces than for asphalt surface. Thus, surfaces with in-between tone and color are more effective than dark- or white-colored ones, and natural or semi-natural surfaces are much greater than artificial ones in improving the urban thermal environment. This study provides new information on correlation between Ts and air temperature, relationship between albedo and Ts, and the energy budget.