• Korean Journal of Veterinary Research
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• v.2 no.2
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• pp.25-27
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• 1962

It was previously reported that aqueous extracts of Radix Jingyu and Fructus ponciri, and also Lycaconitine, an alkaloid of Radix Jingyu, exhibit excellent effects as cattle tick repellent. The repost deals with the field teats carried out with these three drugs for their repellent effects against Korean goat ticks, nearly 99 per cent of which are composed of Haemaphysalis bispinosum and the rest of Boophilus microplus. The study revealed that Korean goat ticks are as susceptible to all three drugs tested as korean cattle ticks.

• Textile Coloration and Finishing
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• v.23 no.2
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• pp.100-106
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• 2011

UV-curable water-repellent finish was carried out to impart one-side repellency to the PET fabrics using a formulation of a UV-active fluorocarbon agent and a water soluble photoinitiator. The aqueous formulation was padded on the PET fabrics and it was subsequently UV-cured. The unirradiated side of the cured fabrics was made to wetteable to water by the prolonged UV/ozone irradiation. The influence of photoinitiator concentration, agent concentration and UV energy for photodegradation on the performance of the finished fabrics were investigated. The difference in the functional property of front and back sides was examined by measuring water repellency at each side of the treated fabrics, which resulted in four rating difference between two-side. The UV-cured and photodegraded PET surfaces were characterized by ATR, ESCA and FE-SEM.

• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.100-104
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• 2013

A superhydrophobic mesh is a unique structure that blocks water, while allowing gases, sound waves, and energy to pass through the holes in the mesh. This mesh is used in various devices, such as gas- and energy-permeable waterproof membranes for underwater sensors and electronic devices. However, it is difficult to fabricate micro- and nano-structures on three-dimensional surfaces, such as the cylindrical surface of a wire mesh. In this research, we successfully produced a superhydrophobic water-repellent mesh with a high contact angle (> $150^{\circ}$) for nanofibrous structures. Conducting polymer (CP) composite nanofibers were evenly coated on a stainless steel mesh surface, to create a superhydrophobic mesh with a pore size of $100{\mu}m$. The nanofiber structure could be controlled by the deposition time. As the deposition time increased, a high-density, hierarchical nanofiber structure was deposited on the mesh. The mesh surface was then coated with Teflon, to reduce the surface energy. The fabricated mesh had a static water contact angle of $163^{\circ}$, and a water-pressure resistance of 1.92 kPa.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.193-194
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• 2018

Tn this present study, the superhydrophobic surface was developed on the cement mortar surface by using water repellent materials. For better superhydropohicity, it was developed by using silane as binder and which was enriched with filler materials of SiO₂ and TiO₂ nanomaterials. Those nanomaterials enriched with silanes were admixed in cement mortar during casting time and another was coated on the cement mortar surface. The water repellent properties of spray coated and admixed cement mortars were evaluated by measuring the contact angle which was compared with normal cement mortar.

• Journal of Forest and Environmental Science
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• v.29 no.2
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• pp.109-115
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• 2013

Fast-grown wood generally contains a high proportion of juvenile wood that results in inferior dimensional stability and durability against biological deteriorations. In the present research, the Acacia mangium wood from plantation forests in Vietnam was treated with high temperature in air. The effects of heat treatment on physical properties of Acacia mangium wood, including mass loss (ML), water absorption (WA), water-repellent effectiveness (WRE) and anti-swelling efficiency (ASE) were examined. The results showed that the dimensional stability and the water-repellent effectiveness are increased by about 15-46% and 8-18%, respectively. However, the mass and dimension of wood are decreased. The results also indicated that both treatment temperature and treatment duration significantly affect the wood properties of Acacia mangium. It is thus concluded that heat treatment demonstrates an interesting potential to improve the wood quality of Acacia mangium for solid timber products. This technology provides an environmentally safe method of protecting sustainable common woods to give a new generation of value-added biomaterials with increased stability without the use of toxic chemicals.

• Transactions on Electrical and Electronic Materials
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• v.18 no.4
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• pp.203-206
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• 2017

The effect of the content of microsilica and nanosilica continuously modified with hydroxy silane and epoxy-modified silicone in cycloaliphatic epoxy/microsilica/nanosilica composites (EMNCs) on the mechanical and water repellent properties was evaluated. Surface-modified micro- and nanosilica was well-mixed with a cycloaliphatic epoxy resin in the presence of polyester-modified polydimethylsiloxane (PEM-PDMS) as a dispersing agent using an ultrasonicator. Tensile and flexural tests were carried out using a universal testing machine (UTM). The water repellent property was evaluated by contact angle measurements of water on the composite surface. Tensile strength of the composite could be enhanced by 32.2% up to 91.4 MPa, and the flexural strength was raised to 122.0 MPa, which is 38.8% higher than that of neat epoxy. The contact angle of water on the composite was as high as $104.1^{\circ}$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.76-77
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• 2021

compared and reviewed the water repellency and strength characteristics by controlling the surface stamping size and fine aggregate ratio of cement mortar mixed with water repellent as a method to control the ecological imitation surface structure. As a result of measuring the contact angle, the higher the ratio of fine aggregate, the larger the contact angle. The contact angle increased when the surface structure was changed by stamping, and increased as the stamping size became smaller. In the surface stamping of mesh#150, the contact angle was particularly increased.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.204-208
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• 2012

Water repellency which affects infiltration, evaporation, erosion and other water transfer mechanisms through soil has been observed under several natural conditions. Water repellency is thought to be caused by hydrophobic organic compounds, which are present as coatings on soil particles or as an interstitial matter between soil particles. This study was conducted to evaluate the characteristics of the water repellent soil and transport characteristics of trace elements within this soil. Capillary height of the water repellent soil was measured. Batch and column studies were accompanied to identify sorption and transport mechanism of trace elements such as $Cu^{2+}$, $Mn^{2+}$, $Fe^{2+}$, $Zn^{2+}$ and $Mo^{5+}$. Difference of sorption capacity between common and repellent soils was observed depended on the degree of repellency. In the column study, the desorption of trace elements and the spatial concentration distribution as a function of time were evaluated. The capillary height was in the repellency order of 0% > 15% > 40% > 70% > 100%. No water was absorbed in soil indicating >70% repellency. Using trace elements, $Fe^{2+}$ and $Mo^{5+}$ showed higher sorption capacity in the repellent soil than in non-repellent soil. The sorption performance of $Fe^{2+}$ was found to be in the repellency order of 40% > 15% > 0%. Our results found that transfer of $Mo^{5+}$ had similar sorption tendency in soils having 0%, 15% and 40% repellency at the beginning, however, the higher desorption capacity was observed as time passes in the repellent soil compared to in non-repellent soils.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.685-699
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• 2013

This study was evaluated the effect of attractant or repellent plants for establishing push-pull strategy for insect pest management of organic Chinese cabbage cultivation. The attractant or repellent effect of Ten plants, marigold, rye, Chinese chive, lettuce, chicory, Nongwoo-chicory, crown daisy, Treviso, green leaf mustard, and red leaf mustard were evaluated against diamondback moth, striped flea beetle, aphids, brown-winged stink bug and cabbage stink bug in organic Chinese cabbage field in Seosan in 2012. Of the ten repellent or attractant plants, rye and chicory attracted significantly brown-winged stink bug and cabbage stink bug, respectively. Aphids ate attracted significantly to the rye rather than the other plants. Leaf mustard was attracted cabbage stink bug and brown-winged stink bug in order. Cabbage stink bug was attracted by only a combination of lettuce and Chinese chive. Diamondback moth, striped flea beetle, aphid, brown-winged stink bug and cabbage stink bug were significantly repelled by single or combined cultivation of crown daisies, Treviso, and leaf mustard in organic Chinese cabbage cultivation. The results above-mentioned indicate that selected insect-attractant and -repellent plants can be used as tools for integrated pest managements of Chinese cabbage.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.389-395
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• 2012

Stored grain insects appear frequently as grains are harvested, stored, and distributed on the market. Producers mostly depend on chemical fumigants to control and repel insect pests, but this application of chemicals may cause side effects for humans and the environment. Safer control approaches, including the use of natural products are required, and in this study, we assessed the control effect of essential oils on stored grain insects. The essential oils of 8 plant species from 6 families were tested for their fumigant toxicity and repellent effects using a Y-tube Olfactometer against Sitophilus zeamais adults. Pennyroyal and tea tree oil respectively exhibited 97% and 63% mortality at $10{\mu}{\ell}L^{-1}$ air concentration in tested fumigant toxicity. Of particular note, pennyroyal oil ($LT_{50}$, hour=3.87) showed higher adulticidal activities than tea tree oil ($LT_{50}$, hour=4.09). When assessing repellent effects, using a Y-tube Olfactometer at $10{\mu}{\ell}$/filter paper concentration, the cedarwood, cinnamon, cypress, patchouli and pennyroyal essential oils showed potent repellent activities against Sitophilus zeamais adults. Cinnamon, cypress and pennyroyal essential oils showed notably high repellent activities of 82.4%, 80.0% and 86.7%, respectively, at $1{\mu}{\ell}$/filter paper concentration.