• Journal of the Optical Society of Korea
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• v.18 no.4
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• pp.395-400
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• 2014

We proposed a method for fast turn-off switching of a vertically-aligned liquid crystal cell by low-temperature curing of the polymer structure. We confirmed that the turn-off times of the fabricated cells were reduced significantly as the curing temperature was lowered to $-20^{\circ}C$. We accounted for the effect of low-temperature curing on the turn-off time by using a mathematical model and by observing images obtained via scanning electron microscopy. We also confirmed that low-temperature curing is more effective in reducing the response time when the device is operated at a low temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.160-160
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• 2016

In this study, we applied the low temperature curing Ag paste to replace PVD System. The electrode formation of low temperature curing Ag paste for silicon Hetero-junction solar cells is important for improving device characteristics such as adhesion, contact resistance, fill factor and conversion efficiency. The low temperature curing Ag paste is composed various additives such as solvent, various organic materials, polymer, and binder. it depends on the curing temperature conditions. The adhesion of the low temperature curing Ag paste was decided by scratch test. The specific contact resistance was measured using the transmission line method. All of the Ag electrodes were experimented at various curing temperatures within the temperature range of $160^{\circ}C-240^{\circ}C$, at $20^{\circ}C$ intervals. The curing time was also changed by varying the conditions of 10-50min. In the optimum curing temperature $200^{\circ}C$ and for 20 min, the measured contact resistance is $19.61m{\Omega}cm^2$. Over temperature $240^{\circ}C$, confirmed bad contact characteristic. We obtained photovoltaic parameter of the industrial size such as Fill Factor (FF), current density (Jsc), open-circuit voltage (Voc) and convert efficiency of up to 76.2%, 38.1 mA/cm2, 646 mV and 18.3%, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.239-240
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• 2022

In winter, low outdoor temperature can casue reduction of concrete strength. Therefore, thermal protection is required when curing concrete in winter to maintain a certain level or higher surface temperature. Accordingly, in domestic construction sites, a curing method in which surrounds casting areas by tents and operates hot air blowers are widely applied. However, local low-temperature areas may occur due to airtightness of the curing tents. If additional heat is supplied to prevent occurrence of local low-temperature areas, energy consumption increases. Therefore in this study, a plan for improvement method of concrete curing was considered and the performance was evaluated through numerical analysis. A plan to improve the airtightness of the wall opening was applied, but the analysis showed that if only a part of the curing area is shielded, the temperature of the unshielded area decreases,making it inappropriate to improve curing performance.

• Journal of the Korea Institute of Building Construction
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• v.7 no.1 s.23
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• pp.71-77
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• 2007

This paper is to investigate the effect of the curing temperature on strength development of concrete incorporating cement kiln dust(CKD) and blast furnace slag (BS) quantitatively. Estimation of the compressive strength of the concrete was conducted using the equivalent age equation and the rate constant model proposed by Carino. Correction of Carino model was studied to secure the accuracy of strength development estimation by introducing correction factors regarding rate constant and age. An increasing curing temperature results in an increase in strength at early age, but with the elapse of age, strength development at high curing temperature decreases compared with that at low curing temperature. Especially, the use of BS has a remarkable strength development at early age and even at later age, high strength is maintained due to accelerated pozzolanic activity resulting from high temperature. Whereas, at low curing temperature, the use of BS leads to a decrease in compressive strength. Accordingly, much attention should be paid to prevent strength loss at low temperature. Based on the strength development estimation using equivalent age equation, good agreements between measured strength and calculated strength are obtained.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.75-78
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• 2005

This raper investigates the effect of curing temperature on strength development of concrete incorporating cement kiln dust(CKD) and blast furnace slag (BS) quantitatively. Estimation of compressive strength of concrete was conducted using equivalent age equation and rate constant model. An increasing curing temperature results in an increase in strength at early age, but with the elapse of age, strength development at high curing temperature decreases compared with that at low curing temperature. Especially, the use of 35 has a remarkable strength development at early age and even at later age, high strength is maintained due to accelerated pozzolanic activity resulting from high temperature. Whereas, at low curing temperature, the use of BS leads to a decrease in compressive strength. Accordingly, much attention should be paid to prevent strength loss at low temperature. Based on the strength development estimation using equivalent age equation, good agreements between measured strength and calculated strength are obtained.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.1 s.20
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• pp.1-7
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• 2006

In the harbor construction work, caisson is made by slip-form method and curing temperature of caisson concrete need heating in the low-temperature. To get the setting time and compression strength of slip-form method applied caisson at various curing temperature. The curing temperature is divided to the temperature of slip-form and the temperature of second curing curtain. In consideration of setting time, compression strength of concrete and form-removal time, the best temperature is $25^{\circ}C$ at 6 hours slip-form curing time.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.45-48
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• 2005

This study is basic experiment for estimating influence of strength by curing temperature of concrete's heat of hydration and estimate relationship of compressive strength development by initial curing temperature factor, and then asume temperature factor which influence compressive strength development and for showing basic document of qualify control. According to the result of cement mortar by the curing temperature factor high-curing temperature shows high strength on 3 day compare with low curing-temperature, shows higher strength than the piece of high curing temperature.

• Journal of Environmental Science International
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• v.19 no.1
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• pp.105-114
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• 2010

The objective of the paper is to experimentally investigate the compressive strength of the concrete incorporating fly ash. Ordinary Portland cement(OPC). Water to binder ratio(W/B) ranging from 30% to 60% and curing temperature ranging from $-10^{\circ}{\sim}65^{\circ}C$ were also adopted for experimental parameters. Fly ash was replaced by 30% of cement contents. According to the results, strength development of concrete contained with fly ash is lower than that of plain concrete in low temperature at early age and maturity. In high curing temperature, the concrete with fly ash has higher strength development than that of low temperature regardless of the elapse of age and maturity. Fly ash can have much effect on the strength development of concrete at the condition of mass concrete, hot weather concreting and the concrete products for the steam curing.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.200-204
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• 2008

The curing kinetics of diglycidyl ether of bisphenol F (DGEBF) with an asymmetric cycloaliphatic amine curing agent were examined by thermal analysis in both isothermal and dynamic curing conditions. From the residual curing of the samples partially cured in isothermal condition and from the dynamic curing with various heating rates, it was found that there exist two kinds of reactions such as at low temperature and at high temperature regions. It was thus also found that the cure parameters obtained from the isothermal curing kinetic model hardly estimate experimental results for a degree of cure larger than 0.6. The activation energies and frequency factors of these two kinds of reactions were obtained from the dynamic curing experiments with various heating rates. From the curing analysis, it was verified that the total cure kinetics for low degrees of cure is dominated by the cure reaction in the low temperature region.

• Journal of the Korea Institute of Building Construction
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• v.8 no.4
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• pp.115-121
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• 2008

The present study performed low-pressure steam curing with mortar specimens in order to examine the temperature profile and strength development of steam curing in high-strength specimens of 100MPa. In addition, as a basic research to utilize PC products, we examined the effects of curing temperature and time in steam curing cycle on strength development resulting from the hydration of cement within the range of high strength by changing four factors affecting the quality of PC displacement time, peak curing temperature, peak temperature duration, and ascending and descending gradient of temperature - in various patterns, and analyzed the optimal strength development characteristic based on the relation between temperature profile and strength development. With regard to the high-temperature curing characteristic of PC, we performed an experiment on the strength characteristic according to the temperature profile of high-strength mortar, and from the results of the experiment according to curing characteristic, displacement time, peak curing temperature, peak temperature duration, and ascending and descending gradient of temperature, we drew conclusions as follows.