• 한국염색가공학회지
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• 제14권4호
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• pp.223-228
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• 2002

Cotton fabric was treated with $TiO_2$-PEG600 dispersion colloid by pad-dry-cure and wet-fixation process to improve the performance properties as well as UV-cut effect. As the concentration of $TiO_2$/PEG increased tensile strength, crease resistance, stiffness of treated cotton fabric increased. Application of wet-fixation method provided a further improvement in tensile strength, crease resistance, stiffness of treated cotton fabric. Cotton fabric treated with $TiO_2$/PEG was more efficient in UV-cut property than untreated cotton.

• Environmental Analysis Health and Toxicology
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• 제16권4호
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• pp.161-170
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• 2001

In aqueous ecosystems, the level of toxicity is highly responsive dependant to multiple variables, including rainfall, sunlight, pH, adhesion, etc. Because Korea has particularly distinct wet and dry seasons, the toxicity of pollutants in rivers or streams is dependant on the sampling season and time. In order to examine the effects of rainfall on toxicity, sediment samples were collected from five sites along the Keumho river. It was found that Microtox toxicity levels were generally higher during the dry season than the wet season. It indicated that river pollutants are carried off more quickly by the water during the wet season. As a result, it was recommended that the point sources of pollutants of the Keumho river would be placed between KH3 (Paldalgyo) and KH4(Keumhogyo), KH4(Keumhogyo) and KH5(Dasa).

• Journal of Mechanical Science and Technology
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• 제15권10호
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• pp.1380-1385
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• 2001

This paper evaluates the fatigue fracture behavior of a chopped strand glass mat/polyester composite both in ai, and sea water, Bending fatigue (R=-1) was performed on dry and wet specimens, that is respectively in air and sea water. Where the pH concentration of sea water was controlled to 6.0,8.2, 10.0 and the wet specimens were immersed in the sea waters for 4 months. Throughout the tests, fatigue cracks both in the dry and wet specimens, tested in the air or sea water, occurred at the beginning of the cycle, followed by either of two regions one decreasing and the other increasing as the crack growth rate increases.

• International Journal of Concrete Structures and Materials
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• 제11권1호
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• pp.69-84
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• 2017

This paper presents results of an experimental investigation on the behaviour of bond between external glass fibre reinforced polymer reinforcement and concrete exposed to three different environmental conditions, namely, temperature cycles, wet-dry cycles and outdoor environment separately for extended durations. Single shear tests (pull-out test) were conducted to investigate bond strengths (pull-out strengths) of control (unexposed) and exposed specimens. Effect of the exposure conditions on the compressive strength of concrete were also investigated separately to understand the effect of changing concrete compressive strength on the pull-out strength. Based on the comparison of experimental results of exposed specimens to control specimens in terms of bond strengths, failure modes and strain profiles, the most significant degradation of pull-out strength was observed in specimens exposed to outdoor environment, whereas temperature cycles did not cause any deterioration of strength.

• 융복합기술연구소 논문집
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• 제1권1호
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• pp.13-17
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• 2011

The car industry is one of the technological applications which more rare earth metals employes as three-way catalysts. Therefore, the recovery of rare earth metals from the used automotive three-way catalysts could be important source to obtain these metals. This work presents the analysis of market and demand for rare earth metal in automotive three-way catalyst and introduces the dry and the wet processes for the recovery of rare earth metals from used three-way catalyst. Finally, the alternative methods to conventional wet processes was simply suggested based on the economic and ecological point of view.

• 로봇학회논문지
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• 제17권3호
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• pp.282-287
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• 2022

High shear adhesion on wet and rough surfaces and tactile feedback of gripping forces are highly important for realizing robotic gripper systems. Here, we propose a bioinspired robotic gripper with highly shear adhesion and sensitive pressure sensor for tactile feedback systems. To achieve them, we fabricated multi-walled carbon nanotube sensing layer on a thin polymeric adhesive layer of polydimethylsiloxane. With densely hexagonal-packed microstructures, the pressure sensor achieved 9 times the sensing property of a sensor without microstructures. We then assembled hexagonal microstructures inspired by the toe pads of a tree frog, giving strong shear adhesion under both dry and wet surfaces such as silicon (42 kPa for dry and ~30 kPa for underwater conditions) without chemical-residues after detachment. Our robotic gripper can prevent damage to weak or smooth surfaces that can be damaged at low pressure through pressure signal feedback suggesting a variety of robotic applications.

• 한국군사과학기술학회지
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• 제11권2호
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• pp.101-108
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• 2008

This study attempted to develop the technology by gaseous ozone for decontaminating building affected by a model of biological weapon agent(Bacillus subtilis spores) instead of Bacillus anthracis spore. The use of ozone is attractive method from a practical point of view of decontamination procedure since it has strong oxidation power but no residue after application. We examined the disinfection efficiency of gaseous ozone to Bacillus subtilis spores which suspension was sprayed on different material surfaces and dried. Three different types of gaseous ozone was applied : dry ozone, dry ozone with humidified air, and water bubbled wet ozone. Dry ozone(1500ppm) failed to achieve any significant inactivation for 2hrs. However, six log reduction of B. subtilis spore was achieved within 30min by 1500ppm of water bubbled wet ozone. This result shows the noticeable inactivation efficiency by gaseous ozone compared with previous studies. Good performance by wet ozone was also found for military material surface.(i.e. : gas mask hood, protective garments, army peinted metal surface).

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.429-429
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• 2012

To investigate the gettering effect of B-doped n-type monocrystalline silicon wafer, we made the p-n junction by diffusing boron into n-type monocrystalline Si substrate and then oxidized the boron doped n-type monocrystalline silicon wafer by in-situ wet and dry oxidation. After oxidation, the minority carrier lifetime was measured by using microwave photoconductance and the sheet resistance by 4-point probe, respectively. The junction depth was analyzed by Secondary Ion Mass Spectrometry (SIMS). Boron diffusion reduced the metal impurities in the bulk of silicon wafer and increased the minority carrier lifetime. In the case of wet oxidation, the sheet resistance value of ${\sim}46{\Omega}/{\Box}$ was obtained at $900^{\circ}C$, depostion time 50 min, and drive-in time 10 min. Uniformity was ~7% at $925^{\circ}C$, deposition time 30 min, and drive-in time 10 min. Finally, the minority carrier lifetime was shown to be increased from $3.3{\mu}s$ for bare wafer to $21.6{\mu}s$ for $900^{\circ}C$, deposition 40 min, and drive-in 10 min condition. In the case of dry oxidation, for the condition of 50 min deposition, 10 min drive-in, and O2 flow of 2000 SCCM, the minority carrier lifetime of 16.3us, the sheet resistance of ${\sim}48{\Omega}/{\Box}$, and uniformity of 2% were measured.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권2호
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• pp.111-116
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• 2000

Transboundary air pollution has recently become an area of increasing scientific interest and political concern as countries are receiving air pollutants from their neighbors. In order to gain a better understanding of the long-range transport processes of air pollutants and the source-receptor relationships among neighboring countries, an atmospheric transport model coupled with a RAMS(Regional Atmospheric Modeling System) model was applied to the East Asia region during the entire month of January 1993. The scalar transport option of the RAMS model was used to calculate special atmospheric constituents such as trace gases or aerosols. The sulfate production in clouds and rainwater and its removal processes by dry and wet deposition were considered. The sulfate budget from source regions to receptor regions was estimated by analysing the source-receptor relationships. When a specific receptor site revealed a sulfate value higher than the sulfate concentration based on its own source origin, this was taken to indicate long-range transport from another source region. The contribution ratio from various source region was calculated. The contribution ratio of dry and wet deposition was higher on the main continent of the East region. Furthermore, the high deposition amounts were identified on the west coast of Korea and the East China Sea.

• 터널과지하공간
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• 제7권2호
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• pp.91-99
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• 1997

To stabilize the energy price, the more storage facilities of energy are required and among the storage methods of LPG and LNG, the method of storage at low temperature under normal confining pressure is considered. It is needed to understand the mechanical and thermal characteristics of rock under temperature variation so that the behaviors of rock can be predicted. In this paper, the variation of the rock charateristics of the Hwangdeung granite and the Boryung sandstone is studied at low temperature. The mechanical characteristics of rock under low temperatures are that as temperature decreased, unaxial compression strength and Young's modulus increased for Hwangdeung granite; strength and Young's modulus in wet condition were greater than those in dry condition. In the case of Boryung sandstone, as temperature decreases unaxial compression strength and Young's modulus increase but decrease below -10$0^{\circ}C$ in dry condition and below -16$0^{\circ}C$ in wet condtion. The mechanical characteristics of rock after cooling to previous temperature and thawing are that uniaxial compression strength and Young's modulus decrease as temperature decreases. Uniaxial compression strength and Young's modulus in wet conditon decrease more than those in dry condition. Brazilian tension strength decreases as temperature decreases.