• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.29 no.3
• /
• pp.60-68
• /
• 1997

To develop paper coating technology for preventing print mottling, which is recognized as the most common printing problems in using coated papers, ink absorption properties of various coated papers were examined by employing K 8T N and Croda ink absorption tests. The influences of pigment compositions, coat weights and drying methods on these ink absorption properties were examined, and then the variations of ink absorption ratio were analyzed and discussed. It is demonstrated that the variation of Croda ink absorption ratio induced by coat weight variation can be utilized most succesfully to predict print mottling propensity of coating formulations. A systematic analysis approach was suggested that can be employed in the development of the most desirable coating color formulation to achieve target optical properties with the least print mottling.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.36 no.3
• /
• pp.175-180
• /
• 2016

Nondestructive evaluation for material health monitoring is important in aerospace industries. Composite laminates are exposed to heat cyclic loading and humid environment depending on flight conditions. Cyclic heat loading and moisture absorption may lead to material degradation such as matrix breaking, debonding, and delamination. In this paper, the moisture absorption ratio was investigated by measuring the Lamb wave velocity. The composite laminates were manufactured and subjected to different thermal aging cycles and moisture absorption. For various conditions of these cycles, not only changes in weight and also ultrasonic wave velocity were measured, and the Lamb wave velocity at various levels of moisture on a carbon-epoxy plate was investigated. Results from the experiment show a linear correlation between moisture absorption ratio and Lamb wave velocity at different thermal fatigue stages. The presented method can be applied as an alternative solution in the online monitoring of composite laminate moisture levels in commercial flights.

• International Journal of Concrete Structures and Materials
• /
• v.10 no.2
• /
• pp.249-256
• /
• 2016

This paper deals with the effects of silica fume content and polymer-binder ratio on the properties of ultrarapid-hardening polymer-modified mortar using silica fume and ethylene-vinyl acetate redispersible polymer powder instead of styrene-butadiene rubber latex to shorten the hardening time. The ultrarapid-hardening polymer-modified mortar was prepared with various silica fume contents and polymer-binder ratios, and tested flexural strength, compressive strength, water absorption, carbonation depth and chloride ion penetration depth. As results, the flexural, compressive and adhesion strengths of the ultrarapid-hardening polymer-modified mortar tended to increase as increasing polymer-binder ratio, and reached the maximums at 4 % of silica fume content. The water absorption, carbonation and chloride ion penetration resistance were improved according to silica fume content and polymer-binder ratio.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.9
• /
• pp.1493-1498
• /
• 2007

In this work, alkyl methacrylate-based microgels were synthesized by an experimental design method, and their sebum absorption characteristics were investigated. The results of fractional factorial experimentation indicated that the cross-linking agent content, solvent content, and stirring speed were the main parameters in the synthesis of the microgels. The suitable synthesis conditions were determined by the response surface design method. Through a study of the monomer and solvent effects, it was confirmed that the microgel shows the highest sebum absorption ratio when t-butyl methacrylate is used as a monomer or when acetone is used as a solvent. The optimal microgel synthesis conditions for cosmetic application were determined, and the resulting microgel had a mean particle size of 4.7 μm and a sebum absorption ratio of 435%.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.217-218
• /
• 2023

This study is to develop porous concrete using super absorbent polymer, which possesses insolubility and high absorption capacity, as a substitute material for lightweight soil. Various mixtures were prepared using aggregates, cement, mixing water, and super absorbent polymer, and the absorption ratio and compressive strength were examined for each mixture. As the amount of super absorbent polymer added increased, the absorption ratio also increased, reaching up to 35-105%. However, the compressive strength decreased by 49.5% to 65.3%. This is believed to be due to the inherent properties of super absorbent polymer, which led to an increase in the absorption ratio but, in turn, reduced the binding strength of cement paste particles, resulting in a decrease in compressive strength.

• Journal of Korean Society for Atmospheric Environment
• /
• v.17 no.5
• /
• pp.407-414
• /
• 2001

In this study, the absorption kinetics of $CO_2$onto a mixture of AMP (2-amino-2-methyl-1-propanol) MEA (monoethanolamine) water were investigated at 30 and 4$0^{\circ}C$ using a packed absorption tower. Solubility and absorption rate of $CO_2$into alkanolamine solutions and optimal condition of $CO_2$absorption process were investigated. The experimental conditions are as follows; temperature of 30 and 4$0^{\circ}C$, gas flow rate of 3ι/min for the absorption tower, and liquid flow rate of 0.1ι/min. Feed gas was a mixture of 85% $N_2$and 15% $CO_2$. The experimental results showed that AMP had greater solubilities and faster absorption rates than MEA and DEA. In addition, MEA had the fastest initial reaction rate. To improve the properties of AMP which have low initial reaction rate and high cost, AMP was used with MEA. The mixing ratio was also changed in constant total molarity of 1,2,3 and 4. The experimental results can be summarized as follows: (1) in solubility experiment, the addition of MEA in constant total polarity decreased the solubility of $CO_2$in AMP/MEA mixture. (2) from 0 to about 0.3 in mixing ratio, the solubility of $CO_2$in AMP/MEA mixture had little differences compared with the sum of solubility of AMP only and solubility of MEA only . (3) mixing ratio of 0.3 was found to be an optimal point with the fastest $CO_2$absorption rate.

• Bulletin of the Korean Chemical Society
• /
• v.8 no.4
• /
• pp.338-340
• /
• 1987

The single-frequency two-photon absorption tensor is carefully rederived and examined. It is pointed out that the conventionally used tensor, which has been formally deduced from the different-frequency two-photon absorption tensor, can give an incorrect absolute two-photon absorption rate. The identity forbidded selection rule and the polarization ratio expressions are also examined with the new tensor.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1992.10a
• /
• pp.37-43
• /
• 1992

Properties of the mortar and the remitar admixed with waterproofer(CS) which was made from cement-sludge were compared with those of the other waterproofers (DA, DD and DH). 1. The CS waterproofer appeared to have a good waterproofness(compressive strength-79%, water absorption ratio-60%, waterpermeability ratio-70%)in cement mortar. 2. The CS waterproofer appeared to have an excellent watertightness(compressive strength-125% water absorption ratio-45%, water permeability ratio-60%) in remitar.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.10a
• /
• pp.223-226
• /
• 2002

This study is performed to investigate the influence of aggregate factor on the estimation of water content in fresh concrete. According to the results, water content is estimated higher in the case of basalt and granite aggregate than in the case of limestone because absorption water ratio of basalt and granite is large. As the replacement ratio of recycled aggregate increases, water content is estimated higher. But, after correcting absorption water ratio of aggregate, estimated water content is similar to mixture water content. Therefore, it is important to know the absorption water ratio of aggregates accurately, to estimate water content.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10a
• /
• pp.567-570
• /
• 2000

This study is designed to manufacture the continuous foamed concrete and the sound absorption characteristics investigation due to continuous voids ratio. According to the results of experiment, it was shown that continuous voids of the foamed concrete has the influence of the amount used of foaming agent, the viscosity and flowability of cement paste, and also is shaped by cohesive power of bubbles. Also the sound absorption ratio of the foamed concrete is subject to increase as the density becomes low by raising the continuous voids ratio. The cement paste with low water-cement ratio and high cement fineness are very effective to prevent weak strength of formed concrete caused by the increase of the porosity.