• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2002.05a
• /
• pp.267-272
• /
• 2002

The electric heat pump requiring HCFCs as a refrigerant has been for most residential air-conditioners in Korea. They cause a surge up electric power demand during summer. Moreover, the use of HCFCs and HFCs causes a serious problem to the global environment such as global warming and ozone layer destruction. An absorption chiller and heater could solve such problems. It was built and tested for analyzing the performance of the absorption chiller/heater. Experiment was done with a 1.5RT household absorption chiller and heater. It was experimented that the cooling capacity, gas capacity, COP were researched by the temperature of cooling water. The change of the cooling water temperature have effect the temperature(or pressure) of the parts on absorption chiller The result of the change of the cooling water temperature have the effects of the absorption chillers. This data will help to operate the household absorption chiller and heater.

• Journal of Ocean Engineering and Technology
• /
• v.17 no.6
• /
• pp.77-82
• /
• 2003

The absorption of water into an anti-corrosive organic coating, such as alkyd and urethane resin coating, was investigated, using a quartz crystal microbalance (QCM). Anticorrosive properties of the coatings were also measured, by means of electrochemical impedance spectroscopy (EIS). The overall absorption of water in the coating is determined by the chemical nature of resin, and decreases with increasing thickness. The enhancement of anti-corrosive performance, through increase of coating thickness, was more remarkable in the case of the coating that hadlower equilibrium water absorption. The absorption kinetics curves were Fickian in nature. The EIS analysis confirmed that the resin, having lower equilibrium water absorption, shows higher anti-corrosive performan.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.63-64
• /
• 2023

In order to reduce the high absorption ratio of spent coffee grounds, this study examined the compressive strength and absorption ratio of mortar replacing coated spent coffee grounds according to the type of water repellent. In order to examine this, as the water repellent used, a silane-based water repellent (fluorine-based water repellent) and an acrylic-based water repellent, which are film-type water repellents, and a silane/siloxane-based water repellent, which are penetration-type water repellents, were used. The spent coffee grounds were coated with each of three water repellents, and mortar was prepared by mixing cement and fine aggregate. As a result of the experiment, the compressive strength and absorption ratio of the mortar replaced with coated spent coffee grounds coated with the film-type water repellent were superior to the penetration-type water repellent. Therefore, in order to reduce the high absorption ratio of spent coffee grounds, a suitable water repellent is a film-type water repellent. Among them, it is judged that the acrylic type has excellent water repellency and is suitable.

• Journal of ILASS-Korea
• /
• v.28 no.1
• /
• pp.10-15
• /
• 2023

Recently, various types of towels and dishcloth dryer products are being widely distributed in Korea. Evaluation methods for water absorption properties of various fabrics have been developed, and there are many studies using them. This study newly intended that whether it is possible to obtain data that can quantitatively analyze the water absorption characteristics of various fabrics, to show the correlation between the water absorption height and the amount of water (water holdup) absorbed, and to experimentally suggest the applicability to evaluate the drying capacity of towel dryer using IR camera. Through these experiments, it was confirmed that quantitative data on the water absorption height of various fabrics can be measured using an IR camera and can be clearly applied to the performance evaluation of actual products.

• Journal of the Korean Electrochemical Society
• /
• v.1 no.1
• /
• pp.55-59
• /
• 1998

The water absorption in protective coatings, which may greatly influence the durability of these coatings, was studied using quartz crystal microbalance and electrochemical impedance technique. The water absorption in protective coatings and the change of coating capacitance with concentration of electrolyte were measured. The water absorption in coatings seems to be driven by osmotic pressure, and larger amount of water was absorbed in thinner coatings at initial stage of absorption. The amount of water absorbed in coatings changed with the type and crosslinking density of resin used in coating formulation. When water absorption and desorption of coating occured by exposing the coatings to electrolyte solutions of different concentration, increase in impedance caused by desorption of water was found to be higher in the case of thinner film.

• Journal of Pharmaceutical Investigation
• /
• v.16 no.3
• /
• pp.101-105
• /
• 1986

The changes of water absorption and surface area of polydimethylsiloxane-5-fluorouracil devices containing different water soluble additives such as sodium chloride, glycerine, poly-propylene glycol(PPG 400), and polyethylene oxide(PEO 400, 400 and 2000) were investigated. It was confirmed that carriers controlled water absorption and swelling of the devices in the aqueous solutions. The water absorption and the swelling were affected by the osmotic pressure and ionic strength of the aqueous solutions.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2012.03a
• /
• pp.88-88
• /
• 2012

Applied decanol and nonanol provided more weight loss than applied heptanol and octanol. PET using decanol showed the highest weight loss than other alcohols applied. Sodium hydroxide caused weight loss in PET fabrics because terephthalic acid and ethylene glycol were separated by the hydrolysis of the ester group in the PET chains. The terephthalic acid was neutralized to disodium terephthalate and the reaction results in weight loss in the PET fabrics. The weight loss increased with increasing hydrolysis time because disodium terepthalate was water soluble and the reaction was not reached at equilibrium. Pretreatment alcohols increased water absorption, especially in case of PET applied decanol revealed the highest water absorption. PET applied decanol showed 400% of initial water absorption, and PET applied nonanol revealed 250% of initial water absorption. However, the pristine PET showed 90% initial water absorption, and it revealed 230% maximum water absorption as compared to other alcohols. Also, PET applied decanol, nonanol, octanol and heptanol showed 600%, 400%, 350% and 300% maximum water absorption, respectively. The result implied alcohol length affected on water absorption of PET fibrous assembly. This implies that the microvoid of the PET surface hold water molecules. Surface morphology of PET appears that the pretreatment reagent attacks almost entire surface of the fiber, causing surface etching. As the surface etching progresses, it propagates inside the fiber, resulting in the formation of elongated cavities on the surface.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.11 s.188
• /
• pp.50-57
• /
• 2006

The water leak in water-cooled generator stator windings can generate the serious accidents such as insulation breakdown and it brings a generator to the unexpected sudden outage. Accordingly, it is important to diagnose the water absorption of them for the effective operation of power plant. Especially, the capacitance value which is measured for diagnosis is very small so the special diagnosis methods like stochastic theory are needed. KEPRI developed the water absorption test equipment and diagnosis technology for them. The developed diagnosis technology is applied to the real system and the results of water absorption test for stator windings are agreed to them of water leak test.

• Polymer(Korea)
• /
• v.37 no.1
• /
• pp.113-120
• /
• 2013

The melt intercalation to commercialize nanocomposites in a pilot scale was applied and the water absorption characteristics for polyamide/MMT nanocomposites manufactured by twin screw extruder was studied. As a result, water absorption decreased with the introduction of MMT and dimensional stability was improved. However, as water absorption increased, flexural strength and modulus were reduced. Therefore, the effect of MMT introduction on mechanical properties of nanocomposites was clearly observed, which may increase the level of strength by maintaining anti-water absorption property of nanocomposite.

• KIEAE Journal
• /
• v.13 no.2
• /
• pp.107-112
• /
• 2013

The purpose of this study is to analyze an insulation property and to establish a design standard for the underground space in architecture. Insulation materials for this study are 12 kinds of Insulation which qualified KS standards(3 classes of EPS type 1, 3 classes of EPS type 2(Neopor), 3 classes of XPS and 3 classes of PU Boards). For insulation materials of underground space, insulating and water tightening property are desired. So conductivity for insulating and water absorption for water tightening are measured in this study. Temperature, insulation is exposed to in the underground space, is different from temperature above the ground. Conductivity is measured in a temperature of $17^{\circ}C$, $20^{\circ}C$, $23^{\circ}C$ and $26^{\circ}C$. In KS standards, water absorption are measure after 24 hours, but insulation is exposed to water for a long time in the underground. So after 110 days, water absorption are measured. As time goes by, increasing of water absorption means decreasing of water tightening and insulating. So after water absorption had measured for 110 days, conductivity has measured again. As a result, XPS is selected as optimized insulation for underground. And Conductivity of XPS insulation with water should be added by 20%.