• Applied Biological Chemistry
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• v.34 no.1
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• pp.21-25
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• 1991

Twenty-six japonica and 19 Tongil type milled rices were grouped based on water uptake rate at $23^{\circ}C$ and interrelationships between starch properties and hydration group were investigated. There were no significant differences in relative crystallinity, transmittance increase rate of 0.1% starch suspension and soluble amylose between japonica and Tongil type rices. The gel volume of starch n 3M KSCN solution of Tonsil type rice starch was significantly higher than that of japonica one. However, no correlations were observed between starch properties and hydration groups.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.810-819
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• 2007

Investigation of alkali activation of fly ash and blast furnace slag was carried out using waterglass and sodium hydroxide. XRD, FTIR, $^{29}Si$ and $^{27}Al$ NMR, TGA and SEM were used to observed the reaction products and microstructure of the fly ash/slag cement (FSC) pastes. The reaction products were amorphous or low-ordered calcium silicate hydrate and aluminosilicate gel produced from alkali activation of blast furnace slag and fly ash, respectively. On the basis of this investigation, waterglass solution with a modulus(Ms) of 1.0 and 1.2 is recommended for alkali activation of fly ash and blast furnace slag. Morphology of FSC pastes alkali-activated with Ms of 1.0 and 1.2 shows a more solid and continuous matrix due to restructuring of gel-like reaction products from alkali-activated fly ash and blast furnace slag together with another hydrolysis product(i.e., silica gel) from water glass.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.581-586
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• 2005

High-performance concrete (HPC), which is particularly sensitive to self-desiccation, is required to be durable even in severe environmental conditions, i.e. costal area, cold district, etc. However, in recent years, some attention was particularly given to cracking sensitivity of high performance concrete at early age. It has been argued and demonstrated experimentally that such concrete undergoes autogenous shrinkage due to self-desiccation at early age under restrained condition, nd, as a result, internal tensile stress may develop, leading to micro cracking and macro cracking. This shrinkage-introduced crack produces a major serviceability problem for concrete structures. One possible method to reduce cracking due to autogenous shrinkage is the addition of expansive additive. Tests conducted by many researches have shown the beneficial effects of addition of expansive additive for reducing the risk of autogenous shrinkage-introduced cracking. However, the research on hydration model of expansion additive has been hardly researched up to now. This paper presents a study of the hydration model of Ettringite-Gypsum type expansive additive. As a result of comparing forecast values with experiment value, proposed model is shown to expressible of hydration of expansive additive.

• Korean journal of food and cookery science
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• v.10 no.2
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• pp.146-150
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• 1994

The addition of nonfish protein significantly reduced the strength of nonfish protein-incorporated surimi gel in terms of cohesiveness, rigidity and shear force. The sensory textural properties of fiberi-3ed surimi gel product was characterized as the reduction in intensity of undesirable rubberiness, chewiness and firmness, thus increasing the desirability in over all texture. Gel strength of both cohesiveness and rigidity of nonfish protein was inversely correlated with those of nonfish protein-incorporated surimi gel. The variation of texture-modifying properties of nonfish protein in surimi gel was attributed to the differences in thermal hydration and gelation properties of nonfish protein.

• Journal of Biomedical Engineering Research
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• v.8 no.2
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• pp.123-134
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• 1987

The transport phenomena of alkali metal chlorides through poly(2 hydroxyethyl methacrylate) hydrogel membrane have been studied using electrodialysis. The hydrogel membranes were prepared by the polymerization of 2-hydroxvethyl methacrylate in the presence of 45%(V/V) H2O and ethyleneglycodimethacrylate. The initiator used in the polymerization was azobismethylisobutyrate (AMIB) prepared from azobisiobtyronitrile (AIBN) using Mortimer method. The permeability of alkali metal chlorides such LiCl, NaCl and KCI at 50 voltage was obtained. The permeability of NaCl was also observed at 30, 40, 50, and 60 voltages respectively. The concentration of solutes permeated through the membrane was measurer by flame photometry. The experimental results have been discussed with the comparison of apparent solute molecular size, the self-diffusion coefficient of solutes, the transport number of cations in aqueous solution. These indic aloes that poly(2 hydroxyethyl methacrylate) hydrogel membrane shows a specific selectivity for sodium ion.

• Journal of the Korean Chemical Society
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• v.34 no.2
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• pp.197-202
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• 1990

Polyethylene glycol (PEG) grafted poly γ-benzyl L-glutamate (PBLG) were prepared from esterification or substitution reaction of PBLG with PEG having hydroxyl group at one end or primary amino groups at both ends. The viscosity of these polymer solution was decreased with decrease of polymer concentration. But in more dilute solution the viscosity was increased with decrease of polymer concentration. PEG-grafted PBLG polymers showed smaller water contact angles than PBLG homopolymer, and the water contact angles of the surface of PEG-grafted PBLG polymers were largely dropped by reacting with aminoethanol, resulting in hydrogel surfaces.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.183-186
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• 1994

Somatic embryos derived from cell suspension cultures of rice were singly alginate-encapsulated to be used as artificial seeds. When placed on half strength MS solid medium,73% of the encapsulated somatic embryos were capable of germination Encapsulation per se did not affect the germination frequency of embryos. When incubated by wrapping with moistured non-sterile filter paper, 60% of the encapsulated somatic embryos germinated. However encapsulated zygotic embryos without endosperm showed a high germination frequency regardless of the sterility of the incubation conditions. The results suggest that a greater susceptibility of somatic embryos to contaminants is attributed to lower germination frequency of encapsulated somatic embryos in non-sterile conditions.

• Journal of the Korean Chemical Society
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• v.40 no.6
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• pp.385-393
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• 1996

The interaction between poly(HEMA) which is material of contact lens containing about 45% water and amino acids (alanine, arginine, methionine, proline, glycine, serine, lysine) have been studied by using the thermal analysis methods through DSC and TGA. The experimental results of DSC and TGA were shown that lysine, arginine and alanine have the most stable interaction between poly(HEMA) and amino acids.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.349-353
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• 2018

Metronidazole (MD), which is used as an antibiotic, is largely used as an oral and skin application agent, and has inhibiting effect on the production of the fungus causing malodor. However, the maximum drug inclusion concentration is 0.75% of skin ointment in commercially available. In this study, hydrogels containing high concentration of metronidazole were prepared by using radiation crosslinking technique based on biocompatible polymers, and release characteristics and antimicrobial properties were evaluated. This study was preliminary carried out to investigate whether it could be used effectively as antibacterial dressing materials.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.145-152
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• 2023

In this study, microscopic observation was made on the surface of cement paste immersed in an aquatic environment for 100 days at electrochemical treatment to mitigate the leaching of alkali ions. To quantitatively rank the hydration products, unhydrated grains and porosity in the interfacial region, the backscattered electron(BSE) images were obtained by scanninng electron microscopy. As a result, it was found that the porosity on the surface was significantly reduced by the electrochemical treatment, while unhydrated grains were more or less increased presumably limited hydration reaction under electric charge. At electrochemical treatment, Ca²⁺ ions present in C-S-H gel could be precipitated with OH^- to form Ca(OH)₂ then to lower C-S-H gel and simultaneously to enhance Ca(OH)₂. Substantially, the risk of alkali leaching could be lowered by the limited ionized matrix under electrochemical treatment.