• Journal of Technologic Dentistry
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• v.32 no.2
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• pp.65-74
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• 2010

Purpose : To understand the impact on the strength or restoration force by the change of heating temperature when soldering 18-8 stainless steel round wire which is the chrome-nickel class for dental orthodontic device production. Methods : The following conclusions were made upon the results from tensile strength test, 3 point bending test, and $90^{\circ}$ bending fatigue test with 24 samples that had been applied with condition 1 (before heat treatment - natural) and condition 2 (after heat treatment - mooring 30 seconds after heating up to $500^{\circ}C$, $700^{\circ}C$, and $900^{\circ}C$) to ${\phi}0.4mm$, ${\phi}0.7{\beta}mm$, 18-8 stainless steel round wire (spring hard) by Jinsung Company. Results : When it was heat-treated at $900^{\circ}C$, both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low tensile strengths compared to the heat treated cases at $500^{\circ}C$ and $700^{\circ}C$ Yield strengths of both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$, as well. Upon the results of 3 point bending test, the heat treated case at $900^{\circ}C$ showed very low in both ${\phi}0.4mm$ and ${\phi}0.7mm$, compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Tensile strength of both ${\phi}0.4mm$ and ${\phi}0.7mm$ as well, showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Upon the results of $90^{\circ}$ bending fatigue test, the heat treated case at $900^{\circ}C$ showed the highest wave node resistance in both ${\phi}0.4mm$ and ${\phi}0.7mm$. Conclusion : This study concluded that heating temperature change during wire soldering impacts on the characteristics of orthodntic wire.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.397-406
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• 2000

Hopkinson effect in the HDDR-treated Nd$\sub$15/Fe$\sub$77/B$\sub$8/ alloy was examined in detail by means of a thermomagnetic analysis with low magnetic field (600 Oe). The emergence and magnitude of maximum in magnetisation in the thermomagnetic curve due to the Hopkinson effect was correlated to the grain structure and coercivity of the HDDR-treated material. the HDDR-treated materials showed clear Hopkinson effect (maximum in magnetisation just below the Curie temperature of the Nd$\sub$2/Fe$\sub$14/B phase) on heating in the thermomagnetic curve. Magnitude of the magnetisation rise due to the Hopkinson effect became smaller as the recombination time increased. The magnetisation recovery at room temperature on cooling from above the Curie temperature became smaller as the recombination time increased. The HDDR-treated materials with shorter recombination time, finer grain size and higher coercivity showed larger magnetisation maximum due to Hopkinson effect in the thermomagnetic curve.

• Journal of Magnetics
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• v.6 no.2
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• pp.61-65
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• 2001

The Hopkinson effect in the HDDR-treated $Nd_{15}Fe_{77}B_8$ allay was examined in detail by means of a thermo-magnetic analysis with low magnetic field (600 Oe). The emergence and magnitude of maximum in magnetisation in the thermomagnetic curve due to the Hopkinson effect was correlated with the grain structure and coercivity of the HDDR-treated material. The HDDR-treated materials showed a clear Hopkinson effect (maximum in magnetisation just below the Curie temperature of the $Nd_2Fe_{14}B\;$ phase) on heating. The magnitude of the magnetisation rise due to the Hopkinson effect became smaller as the recombination time increased. The magnetisation recovery at room temperature on cooling from above the Curie temperature became smaller as the recombination time increased. The HDDR-treated materials with shorter recombination time, finer grain size and higher coercivity showed larger magnetisation maximum due to the Hopkinson effect in the thermo-magnetic curve.

• The Korean Journal of Food And Nutrition
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• v.33 no.1
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• pp.1-8
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• 2020

The purpose of this study was to prevent excessive softening of seasoned spinach by heating and freezing through the pre-heating treatment in calcium chloride solution. The pre-heating temperature was set at 60℃, which supports the highest activity of pectinesterase around 60℃. Pre-heating spinach in calcium solution does not affect the chromaticity characteristics of spinach leaves and significantly improves its texture compared to conventional blanching only and pre-heating in water. The improvement of the firmness is related to the formation of strongly cross-linkages between carboxyl groups and Ca²⁺ by the action of the pectinesterase in spinach. For reheated spinach, the firmness of calcium chloride treated stems were 37.80~44.44 kg, and the control was 28.73 kg. The firmness of calcium chloride treated leaves was 19.73~40.79 kg, and the control was 9.63 kg. Additionally, the total aerobic bacteria in the fresh samples were 3.25~3.99 log CFU/g and 1.97~2.72 log CFU/g in the reheated samples. And the total coliform was not detected in the reheated samples. Considering the color, texture, microbial characteristics and taste quality, the optimum pre-treatment conditions to prevent excessive softening of spinach were 3% calcium chloride solution and 15minutes of treatment.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.73-79
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• 2018

In this study, a torrefaction unit with a capacity of 50 kg/hr was developed and experimented to produce of solid fuel by reuse of the food and agricultural wastes. Dried food wastes and agricultural wastes were used for the experiments and the heated-air torrefaction characteristics were investigated by the raw materials, torrefaction air temperature, and torrefaction time. For the dried agricultural wastes, measured torrefaction capacity and lower heating values were 55.35 kg/hr and 3,333 kcal/kg, respectively. As the lower heating values of the treated samples were greater, by around 7.8%, than those of the non-treated samples, torrefaction process was a very effective method to increase the heating value of the agricultural waste. In case of the dried food waste, torrefaction capacity and lower heating value was measured 88.27 kg/hr and 4,016 kcal/kg, respectively. As the lower heating value of treated ones showed around 9.0% higher than that of non treated ones, torrefaction process is very effective method to increase the heating value of the agricultural waste also. It will be assumed that the heating value shows more higher as increase the air temperature and decrease the moisture content of torrified matter.

• Journal of the Korean Ceramic Society
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• v.31 no.11
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• pp.1387-1395
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• 1994

Re-hydration properties of heated and ground CaO-SiO2-H2O system were studied under hydrothermal condition in order to examine the possibility of recycling ALC waste as raw materials of ALC. Powder of calcium silicate hydrates and ALC waste without heat treatment did not show further hydration while those of heat-treated at proper temperature showed re-hydration properties under hydrothermal condition. The lath-like shape of initially synthesized tobermorite was gradually turned into small debris during heating and plate-like tobermorite was crystallized during re-hydration of the heated powders. Heated and ground ALC waste could be added to natural raw mix for ALC at the ammount up to 20% with increased compressive strength and up to 30% with slightly decreased compressive strength. The optimum heating temperature of ALC for recycling was about 50$0^{\circ}C$.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.98-105
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• 2011

Patterns and levels of aging vary between the book volume and sheets, even though both are made from the same paper materials. In case of book format, the outside is more easily affected than inner side by environmental factors such as temperature, humidity and air. In this study, the change in optical properties after dry heating accelerated aging was comparatively analyzed to understand the difference of the optical aging characteristics between outside and inner side of the duplicated beeswax-treated volume. It is found that the cover pages of the beeswax-treated volumes were more optically deteriorated than their middle pages. This indicates that outer sides of aging book volume directly exposed to the air is more vulnerable to serious deterioration than inner sides. Also, aromatic compounds such as benzoic acid and cinnamic acid were observed in the investigation of UV/VIS absorbance of the beeswax in each aged sample.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1583-1588
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• 1999

Garlic pieces without peeling were subjected to hot air heating at $60{\sim}90^{\circ}C$ for 30 min. and microwave oven heating for 10 sec to reduce the strength of garlic flavor. Volatile compounds of the treated garlic were decreased, as the heating temperature was raised. Garlic heated at 70, 80 and $90^{\circ}C$ had 20%, 31% and 49% less volatile compounds, respectively, compared to those of the control. Microwave oven heating revealed a similar trend to those heated at $60{\sim}80^{\circ}C$. As the heating temperature was raised, glucose, fructose and fructooligosaccharide contents in the heated garlic were decreased. Pyruvic acid contents in garlic, a degradation product of alliin, was decreased as the heating temperature was raised, but contents of the other organic acids were not affected. Arginine, the main amino acid in garlic was decreased by the hot air heating, but was not affected by the microwave heating. Glutamic acid and tyrosine contents were decreased in all the treated garlic samples.

• Fashion & Textile Research Journal
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• v.12 no.4
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• pp.500-507
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• 2010

In this study, physical properties were studied by using latent stretching yarn in order to develop the texturing yarn technique for super bulky yarn, which is better in bulkiness and handle than natural wool and also adds property of synthetic fiber to natural wool. In order to obtain textured conditions by analysing basic properties for manufacturing DTY yarn with super bulky property, DTY 50d/12 after spinning latent yarn spined POY 80d/12 was obtained under the two conditions of (i) false twist(T/M) level 3 in DTY texturing and (ii) draw ratio level 4 in draw texturing. For DTY texturing yarn, Elongation rate increased as the heat treatment time and temperatures increased. In addition, shrinkage became higher as false twist was higher, so that elongation rate became lower. When annealing became longer in time and higher in temperature, initial modulus increased. In addition, as the count of false twist increased, the initial modulus showed higher values. For draw texturing yarn, under the conditions of heat temperature 180 and heating time 30 minutes, shrinkage rate in draw ratio 1.55 and 1.6 draw ratio was 7%, and that in 1.65 and 1.7 draw ratio was 8.5%. High draw ratio samples' tenacity was much influenced by heating time and temperature, but low draw ratio samples' tenacity was influenced not by treated time, but by treated temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.22-22
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• 2009

The silver thick film has been used in many industries such as display, chip, solar cell, automobile, and decoration with conventional heating. The silver thick film is fired with optimal time and temperature. However, decreasing the fabrication time is required due to high production power. Furthermore, there is a problem that silver in electrode is diffused throughout any substrates. For inhibiting the Ag diffusion and long fabrication time we considered a microwave heating. We investigated firing of silver thick film with conventional and microwave heating. The temperature of substrate was measured by thermal paper and the temperature of substrate was under $100\;^{\circ}C$ The shrinkage of electrode was measured with optical microscopy and optical profilometry. The shrinkage of electrode heat treated with microwave for 5min was similar to the that fired by the conventional heating for several hours. After firing by two types of heating, the diffusion of silver was determined using a optical microscope. The microstructure of sintered silver thick film was observed by SEM. Based on our results, the microwave heating should be a candidate heating source for the fabrication electronic devices in terms of saving the tact time and preventing the contamination of substrate.