• Corrosion Science and Technology
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• v.22 no.3
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• pp.175-186
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• 2023

Effects of high-temperature environment and low-temperature environment on corrosion behaviours of 18Cr stainless steels (type 304L, type 441) in simulated selective catalytic reduction (SCR) environments were studied using weight loss test in each environment and rust analysis. With time to exposure to the high-temperature environment, type 441 was more resistant to corrosion than type 304L due to both higher diffusivity of Cr and lower thermal expansion coefficient in α-iron. The former provides a stable protective Cr₂O₃ layer. The latter leaded to low residual stress between scale and steel, reducing the spallation of the scale. With time to exposure to the low-temperature environment, on the other hand, type 304L was more resistant to corrosion than type 441. The lower resistance of type 441 was caused by Cr-depleted zone with less than 11% formed during the pre-exposure to a high-temperature environment, unlike type 304L. It was confirmed by results from the crevice corrosion test of sensitised 11Cr steel. Hence, to achieve higher corrosion resistance in simulated SCR environments, ferritic stainless steels having lower thermal expansion coefficient and higher diffusivity of Cr but containing more than 18% Cr are recommended.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.345-350
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• 2014

This study was conducted to investigate the changes in daily surface temperature of red pepper leaf compared to air and soil surface temperature. The maximum, minimum and average daily temperatures of red pepper leaf were 27.80, 11.40 and $19.01^{\circ}C$, respectively, which were lower by 0.10, 7.60 and $3.86^{\circ}C$ than air temperature, respectively, and lower by 15.00, 0.0 and $4.38^{\circ}C$ than soil surface temperature, respectively. Mean deviations of the difference between measured and estimated temperature by the E&E Model (Eom & Eom, 2013) for the air and surface temperature of red pepper leaf and soil were 0.64, 1.82 and $4.77^{\circ}C$, respectively. The relationships between measured and estimated scaled factor of the air and surface temperature of red pepper leaf and soil were very close to the 1:1 line. Difference between air and surface temperature of red pepper leaf showed a linear decreasing function with the surface temperature of red pepper leaf. Difference between soil surface temperature and air and surface temperature of red pepper leaf linearly increased with the soil surface temperature.

• The Korean Journal of Community Living Science
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• v.21 no.4
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• pp.595-603
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• 2010

The present study was performed on humans to investigate the physiological strain of wearing protective clothing for shielding electromagnetic waves and to compare control clothing that are currently on the market and new clothing that are developed for improving thermal comfort and material weight. Experiments were conducted in a climatic chamber of $28.8{\pm}0.6^{\circ}C$, $37{\pm}5%$RH under three differed experimental clothing conditions: None, Control, New. The results were as follows. Mean skin temperature and rectal temperature in New were significantly lower than that in None and Control (p<.05). The temperature and humidity inside clothing were lower in None (p<.05). Total weight loss was lower in New. Thermal sensation and thermal comfort were less hot and more comfortable in New than those in Control. It was concluded that wearing the protective clothing for shielding electromagnetic waves affects physiological responses such as distribution of body temperature, sweat rate, etc.

• Journal of Ocean Engineering and Technology
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• v.29 no.6
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• pp.481-487
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• 2015

The effects of the heat input and preheat/interpass temperatures on the tensile strength and impact toughness of multipass welded weld metal were investigated and interpreted in terms of the recovery of the alloying elements and microstructure. Increases in both the heat input and preheat/interpass temperatures decreased the tensile strength of the weld metal. A lower recovery of alloying elements, especially Mn and Si, and smaller area fraction of acicular ferrite in the weld metal were observed in higher heat input welding, resulting in a lower tensile strength. In contrast, only a microstructure difference was observed at a higher preheat/interpass temperature. The impact toughness of the weld metal gradually increased with an increase in the heat input because of the lower tensile strength. However, it decreased again when the heat input was larger than 45 kJ/cm because of the much smaller area fraction of acicular ferrite. No effect of the preheat/interpass temperature on the impact toughness was observed. The formation of a weld metal heat-affect zone showed little effect on the impact toughness of the weld metal in this experiment.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.186-192
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• 2014

The spray structures under the stratified and homogeneous charge condition of a gasoline direct injection were investigated in a visualized constant volume chamber. The chamber pressure was controlled from 0.1 MPa to 0.9 MPa by the high pressure nitrogen and the chamber temperatures of $25^{\circ}C$, $60^{\circ}C$ and $80^{\circ}C$ were controlled by the band type heater. The fuel, iso-octane was injected by a 6-hole injector with the pressures of 7 MPa and 12 MPa. From the experiments results, it is confirmed that at lower chamber pressure, the penetration length and spray angle are mainly affected by the chamber temperature with the vaporization of the fuel droplets and generated vortices at the end region of the spray. And at higher chamber pressure, the penetration lengths at the end of the injection were about 50~60% of that at lower chamber pressure regardless of the chamber temperature and the effect of fuel injection pressure is larger than that of the chamber temperature which results from larger penetration lengths at higher fuel injection pressure than at lower fuel injection pressure regardless of the chamber temperatures.

• Textile Coloration and Finishing
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• v.31 no.3
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• pp.155-164
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• 2019

This study comparatively analyzed hair bleaching and degree of damage by the temperature of a heating tool after coloring hair with a permanent, semi-permanent or plant hair dye. According to analysis by spectrophotometer, 'semi-permanent hair dye' was the highest, followed by 'permanent hair dye' and 'plant hair dye' in terms of changes in $L^*$ values. In terms of changes in hair shape when analyzed using FE-SEM, 'semi-permanent hair dye($150^{\circ}C$ or lower)' was the greatest, followed by 'plant hair dye($180^{\circ}C$ or lower)' and 'permanent hair dye($200^{\circ}C$ or lower)'. Therefore, it is reasonable to flat iron hair at low temperature. According to the test, amino acid values gradually decreased in both bleached and colored hair. The results obtained through TGA-based thermal analysis confirmed that as brightness increases, hair moisture contents decrease. This study aimed to protect hair by suggesting a correct use of a flat iron by the hair dye type during hair coloring. It appears that the study results would help hairdressers minimize hair damage by using a hair dye at proper temperature.

• Journal of the Korean Wood Science and Technology
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• v.51 no.4
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• pp.270-282
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• 2023

Lower termites need symbiotic microbes for cellulose digestion. Elizabethkingia miricola strain BM10 has been proposed as a symbiotic microbe that assists in low-temperature digestion and metabolism of Reticulitermes speratus KMT1, a termite on Bukhan Mountain, Seoul, Korea. In E. miricola strain BM10, β-glucosidase genes expressed at 10℃ were identified, and the psychrophilic enzymatic characteristic was confirmed by heterogeneously expressed proteins. Crude β-glucosidase in the culture broth of E. miricola strain BM10 showed specific enzymatic properties, and its substrate affinity was 4.69 times higher than that of Cellic CTec2. Among the genes proposed as β-glucosidase, two genes, bglB_1 and bglA_2, whose gene expression was more than doubled at 10℃ than at 30℃, were identified. They were heterogeneously expressed in Escherichia coli and identified as psychrophilic enzymes with an optimal reaction temperature of about 20℃-25℃. In this study, E. miricola strain BM10, a symbiotic bacterium of lower termites, produced psychrophilic β-glucosidases that contribute to the spread of the low-temperature habitat of a lower termite, R. speratus KMT1.

• The Journal of Korean Medicine
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• v.29 no.3
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• pp.11-20
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• 2008

Objectives: Warm-needling is a method combining the effects of acupuncture with the effects of moxibustion. We need to standardize the characteristics of warm-needling in order to achieve consistency in its operational mechanisms and effects, which will improve clinical ability in the field of Eastern medicine. Methods: In this study, using the LabVIEW system on the warm-needling technique, we measured and compared partial temperature changes which varied according to the density of the moxa cone and the moxa cone's core peak temperature. Results& Conclusions: Examination of the warm-needle's partial temperature in relation to the cone density of the 0.8g moxa specimen suggests that a lower density of the moxa cone corresponds to a higher peak temperature and but with a shorter duration. During the effective stimulus time, the lower the density of the moxa cone, the shorter the duration of the effective stimulus time and the higher the mean temperature. Conversely, the higher the density of the moxa cone, the longer the effective stimulus time and lower the mean temperature.

• Textile Coloration and Finishing
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• v.12 no.5
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• pp.308-314
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• 2000

The dyeability of C. I. Disperse Violet 1 on polyester fiber in alkance including a small amount of water was investigated. Up to 1% of water in alkanes the dye uptakes were increased rapidly. The dyeing transition temperature of the polyester fiber in alkanes with 1% of water was $86.5^\circ{C}$ that is lower by $11^\circ{C}$ than $97.5^\circ{C}$ in alkanes only. This means that water plasticizes the polyester fiber, and that dyes begin to penetrate the polyester fiber at lower temperature. Addition of trichloromethane which is known as a strong plasticizer on polyester fiber, in alkanes, increased the dye uptakes of C. I. Disperse Violet 1 on polyester fiber at $100^\circ{C}$, but the dyeing transition temperature was lower by $3^\circ{C}$ than in alkanes only.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.322-327
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• 2000

Natural convection heat transfer in an enclosure with an opening in the right vertical wall and a heat source at the bottom surface is investigated using a holographic interferometric technique. The effects of the opening length, divider length attached to the top wall, and heater temperature on the temperature distribution are examined. The openging length as well as the divider length greatly affects the degree of inflow and outflow of air. With a small opening, the opening doesn't affect much the upward warm air flow resulting in the symmetric temperature distribution. On the other hand, with the increase of the opening length, the inward cold flow moves the upward flow to the left direction. With the increase of the divider length, temperature in the lower region of enclosure becomes higher for the small opening and lower for the large opening.