• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.154-155
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• 2001

난백과 혈장, 대두단백질은 겔화식품의 겔강화와 단백질 보강의 목적으로 다양하게 사용되고 있으며, 이 때 첨가단백질의 겔화 특성은 가장 중요한 피능적 특성중 하나이다. 이러한 겔화에는 단백질의 종류, 가열온도와 시간, 염의 유무, pH등의 환경이 복합적으로 작용하여, 소수성 상호작용, 공유결합, 이온결합, S-S결합 및 수화력 등이 겔을 형성한다. 단백질의 겔화에 미치는 변수에 대한 많은 연구가 이루어졌지만 단백질의 겔화 특성에 있어 가장 많은 구성비율을 차지하는 수분과 수화력에 관한 연구는 미미한 실정이다. (중략)

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.367-381
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• 2020

This paper presents the seal material mixing ratio of tunnel umbrella arch reinforcement method. Currently, there is no clear standard for the proper gelation time and curing time of the Seal material in Korea, and the quality control is also difficult because it cannot be verified. In response, the ratio of the mixture of the seal material was composed of four types of indoor experiments, and the amount of gelation time and bleed was checked. In addition, a non-cart penetration test confirmed the curing time and compared the ratio of each combination. Further experiments on W/C 120% identified the effect of mixing speed and time on the seal material. A total of three field experiments were conducted based on indoor experiments, and the size and strength of bulb formation were compared by checking the curing time of the specimen and main injection. Comparisons show that the lower W/C, the stronger the strength, the larger the size of the bulb, and the faster the hardening time appears. Based on the results of the gelation time and curing time, it was deemed that the mixing ratio of W/C 120% is most appropriate when applied to the actual site.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.748-753
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• 1999

In gelcasting process of the Si powder slurry mixed with acrylamide monomers, it was characterized the effects of chemical parameters such as monomers and additives(polymerization initiator, catalyst and dispersant), Si powder and humidity at drying on processing parameters such as viscosity and idle time as well as on shrinkage and mechanical strength of green bodies. Generally, idle time decreased as initiator and catalyst amounts were increased, but rather depended on initiator. Idle times of the slurries greatly decreased to less than 1/2 time of the premix solutions in which gelation was delayed at higher MBAM portion as a crosslinking monomer. And fluidity of the slurries became worse at greater than 0.6 wt % dispersant. The green bodies showed only less than 7% of linear shrinkage without crack and distortion when dried for longer than 300 hrs under 98% humidity. Typically, the dried bodies containing 40, 50 vol % of Si powder displayed 64 and 36 Mpa in average, respectively.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.2
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• pp.301-321
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• 2019

The development of a rapidly hardening seal material applicable to steel pipe multistage grouting is described in this paper. In the multistage technique, seal materials are inserted to prevent the backflow of main grouting material. The grouting material must be inserted only after sufficient time has passed for the seal material to reach a gel state. Otherwise, the fluid seal material mixes with the main grouting material and a backflow of the grouting material occurs, thereby making its in situ insertion difficult. Furthermore, if the seal material remains in the gel state for too long a time, it solidifies; and the main grouting material will not be able to seep into the soil. The gel time, i.e., the time needed for the fluid seal material to turn into a gel state, determines the construction period of steel pipe multistage grouting. The gel time is one of the important factors in this technique, because it impacts the total tunnel construction period significantly. This study develops a rapidly hardening calcium aluminate material, which can reduce the gel time and shorten the construction period while retaining proper sealing function. It also presents a method to determine whether the seal material has reached the gel state as well as the quality standard and bleeding rate testing method for the seal material in the gel state.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.144-148
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• 1988

Differential scanning calorimerty(DSC) was used to study gelatinization phenomena of defatted rice, corn, wheat, potato starch and nondefatted rice and wheat starch at heating rate $5{\sim}15^{\circ}C/min$. Gelatinization temperature of defatted rice and wheat starch indicated $4{\sim}5^{\circ}C$ lower temperature than nondefatted starch. More rapid heating rate resulted in a increasing of the gelatinization enthalpy for various starches. A linear relation was observed between water content, heating rate and gelatinization temperature. From the linear relationship existing between water content and gelatinization enthalpy, minimum water content for the gelatinization were 41, 38, 33 and 30% of rice, potato, wheat and corn starch, respectively.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2001.04a
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• pp.37-37
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• 2001

• Journal of the Korean Wood Science and Technology
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• v.27 no.1
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• pp.72-78
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• 1999

To accelerate the curing and to improve the bonding properties of urea-melamine-formaldehyde (UMF) resin adhesives for plywood, the effects of resin compositions and additives on gelation time and bonding strength were discussed. The gelation time of UMF resin prepared by simultaneous reaction with urea(U), melamine(M) and formaldehyde(F) at M/U molar ratio 0.2 was shortened as the molar ratio of formaldehyde to urea was increased. However, at F/U molar ratios higher than 2.5, the amounts of free fomaldehyde of resin could not satisfy with KS standard, Therefore, it was difficult to increase the amount of formaldehyde in resin composition for the purpose of fast gelation time. With increasing the molar ratio of melamine to urea(M/U) from 0.3 to 0.6 at constant F/U molar ratio 3.4, the gelation time of UMF resin was slightly decreased, while gradually increased at M/U molar ratio higher than 0.6. The gelation properties of UMF resin and bonding strength of UMF-bonded plywood could be enhanced by using ammonium chloride and p-toluene sulfonic acid as a curing-agent together with wheat flour and corngluten powder as a extender.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.147-150
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• 1995

Effects of gelation conditions on physical properties of dover sole skin gelatin prepared by fractional precipitation with ethanol were investigated. The physical properties such as gel strength, melting point and gelling point of both ethanol treated and non-ethanoltreated gelatins were improved as concentration of gelatin was increased. The physical property of 10% ethanol treated gelatin sol reached maximum at pH 6.0, whereas non-treated one showed maximum at pH 5.0. Both ethanol treated and non-treated gelatin gel showed the higher gel strength and melting point at lower temperatures and longer period of time. Generally, the physical properties of ethanol treated gelatin gel was better than those of non-ethanol treated gel.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.483-486
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• 1995

With a view to increase utility of ethanol fractionated fish skin gelatin as a food source, the effect of gelation condition on physical properties of the gelatin was investigated. The physical properties of gelatins treated with or without ethanol were improved with a concentration of gelatin increased. The properties such as gel strength, melting point and gelling point of 10% gelatin sol or gel were reached to maximum at pH 6.0 in ethanol treated gelatin and pH 5.0 in non treated one, respectively. Gel strength and melting point of both gelatin gels chilled for long time at low temperature were superior to those of both gelatin gels chilled for short time at high temperature. Gel strength, melting point and gelling point of ethanol treated gelatin gel or sol prepared under optimized gelation conditioning were superior to those of non treated one.

• Polymer(Korea)
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• v.24 no.6
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• pp.787-793
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• 2000

The acrylonitrile copolymer/dimethylformamide (DMF) solutions were prepared to investigate the gelation behavior and critical gel concentration (c＊). Gelation is rapidly progressed with the increase of molecular weight of copolymer, but significantly delayed with supercooling temperature and comonomer contents. The c＊ behavior showed contrary trend against gelation behavior. In dynamic viscoelastic test, two glass-transition region were observed in film obtained from gelled solution whereas one glass-transition in film obtained from true solution. This result supports the idea that an ordered junction zone is formed by the dipole-dipole interaction of intermolecularly neighboring stereo-regular parts of atactic acrylonitrile copolymer chains due to a nucleation process in the solution.