• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.11
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• pp.1798-1811
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• 2010

This research evaluates the changes in the comfort-related properties of high-density fabric, such as moisture permeability and waterproofness, in order to assess the relative importance of laundry conditions for clothing properties after repeated laundering and suggest the best laundering conditions for high-density fabric through the identification of the most influential factor. A commercial high-density fabric was washed 25 times in a drum-type washer using nine different laundry conditions based on profiles derived from a fractional factorial design. To evaluate the changes in the comfort-related properties of the fabric, pore size, air permeability, water vapor transport, water repellency, and water resistance were measured. The comfort-related properties of the fabric deteriorated after repeated laundering by the damaged surface finish; in addition, the damaged surface also changed the pore size. As a result, the water repellency and water resistance decreased. The detergent was the most responsible factor to change the properties among the four factors of detergent, hardness, temperature, and RPM. The best laundering conditions for the fabric was a neutral detergent, soft water of 70ppm, a temperature of $15^{\circ}C$, and 30rpm.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.393-404
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• 2020

This study examined the material properties of MDF manufactured using acetylated pinus radiata fibers against moisture and compared the properties with the fiberboard quality standards of KS F 3200. Since acetylated MDF shows very low moisture content, water absorption and thickness swelling than the quality standards, it is expected to have an excellent dimensional stability. The bending strength in wetting condition of the acetylated MDF reached approximately 70% of the bending strength in dry condition, making it suitable for the quality standards. The internal bond of the acetylated MDF in the wetting condition was higher than the minimum internal bond of the quality standards in the dry condition, showing a good water resistance. Since the water droplet contact angle of the acetylated MDF is larger than that of untreated MDF, it is determined that it contributes in improving the water resistance due to the low wettability.

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.107-116
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• 2013

PURPOSES: The liquid-type chemical warm-mix asphalt (WMA) additive has been developed. This study evaluates the basic properties of the additive and the mechanical properties of WMA asphalt and mixture manufactured by using the newly developed chemical additive. METHODS: First, the newly developed WMA additive was applied to the original asphalt by various composition of additive components and dosage ratio of additive. These WMA asphalt binders were evaluated in terms of penetration, softening point, rotational viscosity, and PG grade. Based on the binder test results, one best candidate was chosen to apply to the mixture and then the mechanical properties of WMA mixture were evaluated for moisture susceptibility, dynamic modulus, and rutting and fatigue resistance. RESULTS : According to the binder test, WMA asphalt binders showed the similar properties to the original asphalt binder except the penetraion index of WMA additive was a little higher than original binder. From the Superpave mix design, the optimum asphalt content and volumetric properties of WMA mixture were almost the same with those of hot mix asphalt (HMA) mixture even though the production and compaction temperatures were $30^{\circ}C$ lower for the WMA mixture. From the first set of performance evaluation, it was found that the WMA mixture would have some problem in moisture susceptibility. The additive was modified to improve the resistance to moisture and the second set of performance evaluation showed that the WMA mixture with modified chemical additive would have the similar performance to HMA mixture. CONCLUSIONS : Based on the various laboratory tests, it was concluded that the newly developed chemical WMA additve could be successfully used to produce the WMA mixture with the comparable performance to the HMA mixture. These laboratory evaluations should be confirmed by applying this additive to the field and monitoring the long-term performance of the pavement, which are scheduled in the near future.

• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.70-86
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• 2024

Termites are a serious threat to wood-based products in Indonesia. This study investigated the termite resistant property of glulam made from polystyrene-modified wood. Three tropical fast-growing wood species, namely mangium (Acacia mangium), manii (Maesopsis eminii), and rubberwood (Hevea brasiliensis), were prepared for flat-sawn laminae. After getting air-dried condition, the laminae were impregnated with polystyrene using potassium peroxydisulphate as a catalyst followed by polymerization at 80℃. Polystyrene-impregnated and control glued-laminated lumbers (glulams) were manufactured, and solid wood was provided. Three wood species and three wood products with six replicates were exposed in a field in Bogor, Indonesia, for four months, and before the tests, their density and moisture content were measured. At the end of the field tests, the weight loss and protection levels of each test sample were determined. A completely randomized factorial design was used for data analysis. The weight percentage gains for mangium, manii, and rubberwood were 22.30%, 18.22%, and 10.44%, respectively. The results showed that manii belonged to low-density wood, whereas the other two woods were medium-density wood, and the moisture content was the ambient moisture content, typical of the Bogor area. Regarding weight loss and protection level, mangium was the most durable against subterranean termite attacks, followed by rubberwood and manii. Among the wood products, the polystyrene-impregnated glulam presented the highest durability, followed by the control glulam and solid wood. Therefore, mangium and rubberwood polystyrene-impregnated glulams are recommended for future product development.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.205-210
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• 1991

The freezing resistance of Eleocharis kuroguqai was evaluated in artifical and natural freezing conditions in relation to tuber size, depth of tuber burial and soil moisture conditions. Osmotic potential of immature and mature tuber of E. kuroguqai before hardening was -12.1 and -23.5 bar, respectively, but decreased to -61. 0 and -67.1 bar after 120-day hardening period. Percent survival of E. kuroguqai tubers during the winter period was 13% and 67% in dry and moist moisture conditions at burial of 5cm depth, but all tubers were survived in the three moisture conditions employed when buried at 25cm depth. Greater decrease of osmotic potential was observed in tubers buried at 5cm depth than tubers buried at 25cm depth, resulting in greater freezing resistance in the former. Large tuber was more susceptable to freezing temperatures than small tuber.

• Journal of Industrial Technology
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• v.36
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• pp.83-88
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• 2016

In this study, a series of experiment was carried to improve dewaterability of the sludge produced in a treatment plant, located in Hongcheon, Gangwondo, which has been treating municipal wastewater and livestock wastewater. Optimum sludge mixing ratio and the amount of sludge conditioner were determined. As sludge conditioners, alum and ferric salt were selected and tested. For the measurement of sludge dewaterability, capillary suction time(CST) and the specific resistance were measured, The specific resistance was detemined by running a series of Buchner Funnel Test. Mixing the two sludges at a 50:50 ratio with the addition of 20 mL alum gave the best results in terms of dewaterability. The moisture content decreased by 2% at this condition.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.49-58
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• 1998

An experimental study was performed to discover the effect of adsorbed moisture on the rolling resistance behavior of pure silver coated 52100 bearing steel. Plasma surface modifications were performed on the silver coated specimen to change the wetting characteristics. Experiments using a thrust ball beating-typed roiling test-rig were performed under vacuum, dry air and various tmmidity conditions. Results showed that the changes in the wetting characteristics influenced remarkably on the silver particle agglomeration and resulted in the different behavior of rolling resistance with humidity.

• Tribology and Lubricants
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• v.15 no.4
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• pp.321-327
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• 1999

An experimental study was performed to discover the effect of adsorbed moisture on the rolling resistance behavior of pure silver-coated 52100 bearing steel. Plasma surface modifications were performed on the silver-coated specimen to change the wetting characteristics. Experiments using a thrust ball bearing-type rolling test-rig were performed under vacuum, dry air and various humidity conditions. Results showed that the changes in the wetting characteristics influenced remarkably on the silver particle agglomeration and resulted in the different behavior of rolling resistance with humidity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.558-559
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• 2005

Recently, polymer insulators that are used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination that lead to dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. In this paper, the tracking property of polymer suspension insulator for power transmission is investigated with CEA tracking wheel test. The diagnosis of insulator sample in tracking test has been analyzed by leakage current, STRI Guide, SEM, FTIR and thermal image.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.536-543
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• 2016

The installation of grounding systems is important for the safe operation of power systems, and the soil resistivity is an important design consideration for such systems. It varies markedly with the soil type, moisture content and temperature. The Jeju geological structure is formed in a multi-layered structure characteristic of volcanic areas and, and the geological ground resistance values can appear even constructed the same areas ground system different from the soil structure. In this study, a mock-up system using representative soil from Jeju was constructed to analyze the variation of the grounding resistance. The mock-up system was configured using the Gauss-Newton algorithm inversion method to analyze the model numerically using the Wenner method through the soil resistivity measurements used to create the ground model. Also, we analyzed the change in the general ground resistance characteristics of the copper rod, copper pipe, and carbon rod that are used for grounding. The variation of the grounding resistance with the hydration status was found to be $2.9[{\Omega}]$, $16.5[{\Omega}]$ and $20.1[{\Omega}]$ for the copper rod, copper pipes, and carbon rod, respectively, and the influence of the ground moisture resistance of the carbon rod was found to be the lowest with a value of $141[{\Omega}]$.