• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.627-632
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• 2002

This study was investigated the changes of gel properties about pH, color and water holding capacity at various hydration time and temperature of food-grade additives (BPP: bovine plasma protein, DEW: dried egg white, SPI: soy protein isolate). The changes of rheological properties were checked about hydration time and temperature. Hydration time and temperature affected pH value, hydration decreased pH of SPI and DEW. The BPP was not influenced at hydration time and temperature. Some Hydration condition increased jelly strength of food-grade additive, but SPI did not form a gel at all hydration condition. Hydration increased lightness of food-protein.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.809-814
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• 2002

Recently, the properties of early-age concrete are increasingly important because these properties directly influence the behavior of early-age concrete structures including stress and cracking behavior. Nevertheless, the studies on early-age concrete are limited to strength and temperature development. The purpose of present study is to propose a simple and rational method which can predict the stress and strain behavior of young age concrete. A series of test have been done to measure the temperature development, strains and stresses in concrete members. The concept of equivalent age was used to define the degree of hydration and this degree of hydration was used to calculate the strength and elastic modulus. The critical degree of hydration and thermal expansion coefficient were calculated using experimental data. It is seen that the critical degree of hydration range from 0.05 to 0.11 based on the measuring method. The thermal expansion coefficient was calculated based on the measured non-mechanical strain and it is found that the coefficient decreases slightly with the increase of age. The consideration of critical degree of hydration in calculating stresses gives more accurate results. The present study provides useful method and data in evaluating early-age behavior of concrete structure.

• Journal of the Korean Ceramic Society
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• v.18 no.4
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• pp.237-246
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• 1981

The effects of impurities, included in the by-produced phosphogypsum from the dihydrate process, on the hydration of portland cement were studied. Six gypsums were adopted in this study; four different raw phosphogypsums from domestic fertilizer plants, a reprocessed phosphogypsum and a reagent grade pure gypsum. Cements with differing $SO_3$ content, were synthesized by grinding two different commercial clinkers and the above six gypsums together. The effects of the impurities were investigated by measuring the setting time, the non-evaporable water coatent, X-ray phase analysis of cement pastes and the compressive strength of cement mortar specimens. It was found that the soluble $P_2O_5$ known as one of injurious impurities on the hydration of portland cement, included in the demestic raw phosghoypsum cxneedigply by far the specified amounts of the Korean Industrial Standards (L9005), and retarded the setting time severely, thus the strength development of cement was delayed at the earlier stage of hydration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.229-230
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• 2023

In this study, the hydration heat differential method was applied to mass concrete structures, and the hydration heat analysis was compared and analyzed with on-site measurement results. The results showed that the temperature history measurements of mass concrete were managed at a difference of 8.4 ℃, and although there was some deviation in thermal stress, a similar trend was observed. Consequently, it was determined that the thermal stress on the surface of mass concrete is less than its tensile strength, which would prevent the occurrence of thermal cracks.

• Food Science of Animal Resources
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• v.18 no.1
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• pp.35-41
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• 1998

The objective of this study was to examine the changes of physical properties by additions of different kinds of stabilizers milk proteins concentration, when stored at 4$^{\circ}C$ or 20$^{\circ}C$ for yoghurt. the results were summarized as follows: 1. Addition of 2% carboxyl methyl cellulose and carrageenan, gelation 0.4%, pectin and starch 0.6%, and carrageenan & pectin 0.8% in the manufacture of yoghurt increased the viscosity, water-holding capacity and protein hydration of yoghurt. 2. Addition of 3% skim milk powder, Ca-caseinate or Na-caseinate 0.6% increased the viscosity, water-holding capacity and protein hydration of yoghurt. 3. Twenty five percent of evaporation of milk promoted to build up the optimal structure of the micelles of yoghurt and improved viscosity, water-holding capacity and protein hydration of yoghurt. 4. Addition of stabilizers to yoghurt showed an increase of viscosity, water-holding capacity and protein hydration when compared with non-addition of stabilizers to yoghurt at 4$^{\circ}C$, 20$^{\circ}C$ storage for 12hrs, 96hrs followed by the decrease of it.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.266-271
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• 2000

This study was performed to find out how much water the cement hydration reaction need. It is real situation that it is difficult to find out the amount of chemical combined water with stoichiometric chemical reaction form. Because several variation occurred during hydration reaction it's not easy to divide water which used at cement paste mixture. In this study high temperature(105$^{\circ}C$) dry method was used to divide evaporable water and non-evaporable water. The last is combined water chemically and some free water absorbed to products of hydration physically. The test was processed with variation of water cement ratio from 10% to 45% with 5% intervals. The weight of cement paste specimens were measured after dry for 72hours at each checking time(0.5, 1, 3, 5, 10, 24, 48, 72, 168hour). In this study some conclusions such as follows were derived. Firstly, Pure combined water contents required at cement hydration result in 23.3percent of the weight of cement. Secondly, The sufficient mixing water needed to fully hydrated cement result in about 40∼45percent of weight of cement. That is, gel pores water could be about 16.7∼21.7percent of weight of cement.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.136-140
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• 1983

The hydration characteristics of barley kernels with various polishing yields were investigated at temperatures of $20-60^{\circ}C$ and their sorption kinetics were studied. The moisture gain in initial stage of hydration was directly proportional to square root of hydration time and there was a break point at the moisture gain of 0.45-0.55g $H_2O/g$ solid. The hydration rate was great in order of polishing yield of 50, 70, 95, 90 and 100%, and increased with increasing hydration temperature. The diffusivity of water into barley kernels followed Arrhenius equation, and the activation energies in hydration reaction of polished barley were ranged from 6.9 to 9.5 Kcal/mole and that of non-polished one was 11.6Kcal/mole.

• Advances in materials Research
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• v.1 no.4
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• pp.269-284
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• 2012

Thermoresponsive hydrogels based on N-Isopropylacrylamide (NIPAM) and 2-Hydroxyethylacrylate (HEA) were prepared by free radical polymerization. The hydrogels were characterized by elemental (CHN) analysis, differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). DSC thermogram showed two endothermic transitions which are due to hydration of water present in different environments. One near $0^{\circ}C$ called melting transition of ice and was used to calculate the quantitative determination of the amounts of freezing and non freezing water. The other transition above the ambient temperature was due to the combination of hydrophobic hydration and hydrophilic hydration which changes with the copolymer compositions. Swelling and deswelling studies of the hydrogels were carried out using the aqueous media, salt and urea solutions. The experimental results from swelling studies revealed that copolymers have lower rates of swelling and deswelling than the homopolymer.

• Journal of the Korean Chemical Society
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• v.22 no.6
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• pp.403-411
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• 1978

A theoretical study of the hydration of the model compound of collagen, poly(Gly-Pro-Pro), has been carried out using empirical potential energy functions. The optimum locations and binding energies of water molecules bound to the model compound have been determined by minimizing the interaction energy. The stabilization energy due to the presence of water in the first hydration shell has been evaluated by comparing the internal interaction energies between the different groups of the model compound in its non-hydrated and hydrated states. The different energy components contributing to the overall stabilization are determined and discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.457-462
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• 2003

It studies the non-structural crack factors that are produced in Steel Box Girder Bridge concrete floor plate using analytical method. It mainly studies humidity and design standard of concrete strength. It used MIDAS CIVIL Ver 5.4.0, a general structure analysis program that applies drying shrinkage rate of domestic road bridge design standard and standard value of creep coefficient, CEF-FIP standard equation and ACI standard equation from the aspect of creep, drying shrinkage and hydration heat to see the effect of the two factors on concrete crack and found the following result. The analytical results of this study showed that the initial stress, which was obtained by ACI standard, exceeds the allowable tensile stress between 5 to 18 days. This result means that even if a bridge is designed and constructed according to design standard, the bridge can have cracks due to various variables such as drying shrinkage, hydration heat and creep that produce stress in slab.