• Title/Summary/Keyword: Repellent

Search Result 334, Processing Time 0.045 seconds

An Experimental Evaluation on Performance of Surface Protector for Concrete Structures (콘크리트 구조물 표면 보호재의 성능에 대한 실험적 평가)

  • Nam, Yong-Hyuk;Chung, Young-Jun;Jang, Suk-Hwan;An, Young-Ki
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.10 no.5
    • /
    • pp.157-163
    • /
    • 2006
  • This study is on the evaluation of double surface protection method using water repellent primer and final top coat to protect concrete. Water repellent agent has been applied on the final top coat to protect concrete. However, to make up for the weakness to the ultraviolet of the water repellent, the work procedure of these protectors is done vice versa. This combination of protectors was compared with existing ones in this study. Even though the final top coat was applied on the water repellent primer, its adhesive strength met to KS F 4936-' 03 with other protectors used in this study. All surface protectors used in this study were excellent in protecting concrete. Especially, in case of applying with final top coat in conjunction with water repellent primer, the resistance against chloride ion penetration and neutralization by $CO_2$ was more efficient than other surface protectors used in this study under this given condition.

Insecticidal Activities and Repellent Effects of Plant Extracts against the Brown Planthopper (Nilaparvata lugens Stäl) (벼멸구에 대한 식물추출물의 살충활성과 기피효과)

  • Kim, Yeon-Kook;Lee, Jong-Jin;Choi, Man-Young
    • Korean journal of applied entomology
    • /
    • v.47 no.1
    • /
    • pp.65-74
    • /
    • 2008
  • Methanol extracts of 35 plant species in 20 families were tested for their insecticidal activities and repellent effects against Nilaparvata lugens female adult by topical application and spray methods. The insecticidal activities and repellent effects of variousplant species and parts were different. The methanol extracts from stem of Garcinia xanthochymus, Senecio scandens and Phytolacca americana, seedcoat of Ginkgo biloba, and leaf+stem of Ailanthus altissima and Catalpa ovata showed potent insecticidal activities against N. lugens. Specially, the G. biloba extract exhibited higher than 90% mortality against N. lugens at a concentration of 4,000 ppm. Repellent effects of plant extracts obtained from whole plant of Daucus carota, fruit of Semecarpus anacardium, leaf+stem of C. ovata and Wisteria sinensis were active, and potent. Also, the plant extracts that are potent in insecticidal activity not necessarily have high repellent activity showing no significant corelation between the two activities.

Experimental Study on Physical Properties and Water Absorption Resistance Evaluation of Cement Mortar Incorporating Inorganic Metal Salt-based Water Repellent Powder (무기물 금속염계 발수분체를 혼입한 시멘트 모르타르의 물리적 특성 및 수분흡수저항성에 대한 실험적 연구)

  • Lee, Won Geun;Yoon, Chang Bok
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.9 no.4
    • /
    • pp.609-616
    • /
    • 2021
  • In this experimental, water-repellent powder, which is a metal salt-based inorganic substance, and natural zeolite powder, which is a pozzolan-based material, were mixed into cement mortar, and their physical properties and resistance to moisture were confirmed. It was confirmed that the test specimen using natural zeolite at the same time had excellent resistance in the water permeation test and the chloride penetration test as compared with the test specimen in which the inorganic metal salt-based water-repellent powder was mixed alone. When a metal salt-based water-repellent powder is used, it cannot be uniformly dispersed inside water due to its insoluble property, and is limited to the surface. When used at the same time as natural zeolite, the setting time at the initial stage of hydration is fast due to the pozzolan reaction, and the water-repellent powder adheres to the porous of the natural zeolite and is evenly distributed inside the test specimen to generate some water resistance.

Repellent Effects of Peppermint Oil Against Pochazia shantungensis (Hemiptera: Ricaniidae) (박하유의 갈색날개매미충(Pochazia shantungensis)에 대한 기피효과)

  • Ryu, Tae Hee;Kwon, Hye Ri;Yu, Yong Man;Youn, Young Nam
    • Korean journal of applied entomology
    • /
    • v.55 no.3
    • /
    • pp.223-233
    • /
    • 2016
  • In order to identify a new control measure for a sporadic insect pest, Pochazia shantungensis, 23 types of essential oils were screened for their repellent effects, with an olfactory test using a Y-tube olfactometer. Results indicated that 21 essential oils, except lemongrass oil and peppermint oil, did not show repellent activity against P. shantungensis. The repellent effect of peppermint oil was over 80%. When 0.1, 0.5, and $1{\mu}l$ of peppermint oil were used, the rate of repelling of P. shantungensis gradually increased, and was as high as 76.5% when $10{\mu}l$ was used. The main components of peppermint oil were 1,8-cineole, iso-menthyl acetate, menthone, and menthol, at 4.7, 8.0, 23.8 and 53.7%, respectively. When the three main components were mixed using a Y-tube olfactometer, a strong repellent effect (76.2%) was observed when $5{\mu}l$ was used. Peppermint oil showed a repellent and ovipositional repellent effect against P. shantungensis in the field. However, this activity persists only for a short period, and high concentrations can lead to phytotoxicity. Therefore, it is necessary to develop ideal formulations.

Repellent Activity of the Extracts of Acorus Gramineus against Mosquito (Culex pipinens pallens) (석창포 추출물의 모기에 대한 기피활성)

  • Lee, Seung-Ho;Jung, Jin-Kwan;Park, Sang-Hyun;Kim, Mun-Sik;Han, Yeon-Soo;Seo, Jung-Mi;Kim, In-Seon
    • Korean Journal of Environmental Agriculture
    • /
    • v.30 no.1
    • /
    • pp.76-81
    • /
    • 2011
  • BACKGROUND: Acorus gramineus is of medicinal plants that exhibit variable biological activities for human health and against insect pests. The extracts of A. gramineus was examined in an attempt to develop a natural repellent against human disease-mediating Culex pipiens. METHODS AND RESULTS: The roots of A. gramineus dried under dark conditions were homogenized and extracted with ethanol. The extracts were subjected to repellent activity assays against C. pipiens in a hand-made acrylamide box with three accessible rooms. Significantly low number of mosquitos was found in the room previously fumigated with the extracts at 50 mg/L on the filter paper, exhibiting less than 20% of mosquitos tested. More than 50% of mosquitos tested was found in the room without the extracts, but less than 30% was found in the room that released mosquitos. GC/MS analysis detected ${\beta}$-asarone as a main component of the extracts. The commercial asarones (${\alpha}$ and ${\beta}$) showed a repellent activity at 50 mg/L on the filter paper similar to the extracts. CONCLUSION(S): A. gramineus has potential for use as a mosquito repellent since ${\beta}$-asarone, a main component of the plant, exhibited a strong repellent activity against C. pipiens.

The Biological Functionality of Electro-Galvanized Steels Coated with a Hybrid Composite Containing Pyrethroid

  • Jo, Du-Hwan;Kim, Myung-Soo;Kim, Jong-Sang;Oh, Hyun-Woo
    • Corrosion Science and Technology
    • /
    • v.17 no.2
    • /
    • pp.74-80
    • /
    • 2018
  • The electronic industries require environmentally-friendly and highly functional materials to enhance the quality of human life. Home appliances require insect repellent steels that work to protect household microwave ovens from incurring damage by insects such as fire ants and cockroaches in tropical regions. Thus, POSCO has developed new types of functional steels, coated with an array of organic-inorganic hybrid composites on the steel surface, to cover panels in microwave ovens and refrigerators. The composite solution uses a fine dispersion of hybrid solution with polymeric resin, inorganic and a pyrethroid additive in aqueous media. The hybrid composite solution coats the steel surface, by using a roll coater and is cured using an induction curing furnace on both the continuous galvanizing line and the electro-galvanizing line. The new steels were evaluated for quality performances, salt spray test for corrosion resistance and biological performance for both insect repellent and antimicrobial activity. The new steels with organic-inorganic composite coating exhibit extraordinarily biological functionalities, for both insect repellent and antimicrobial activities for short and long term tests. The composite-coating solution and experimental results are discussed and suggest that the molecular level dispersion of insecticide on the coating layer is key to biological functional performances.

Development of Natural Dyed Korean Traditional Paper for Cultural Properties Conservation and Storage (Part 2) - Antifungal, Insect Repellent Activities and Stability on Metals - (문화재 보존·보관용 천연염색지 개발(제2보) - 천연염색지의 기능성 연구 -)

  • Lee, Sang-Hyun;Yoo, Seung-Il;Choi, Tae-Ho
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.48 no.3
    • /
    • pp.80-90
    • /
    • 2016
  • The purpose of this study was to investigate the functional properties of natural dyed Hanji for cultural properties conservation and storage. To estimate functional properties of Hanji, antimicrobial, insect repellent test, and Oddy test were executed. Hanji dyed with 10% Golden thread (Coptis chinensis), a natural dye and silver nitrate mordanting showed the most excellent antifungal activities against A. niger, P. chrysogenum, and Trichoderma sp. before and after aging. The insects repellent test followed didn't indicate significant effects on treated Hanji against Lasioderma serricorne, Sitophilus zeamais, and Tribolium castaneum. According to Oddy test result, Hanji dyed with Golden thread and silver nitrate caused no significant corrosions on copper, silver, and lead after aging 28 days.

Development of Cost-effective Mosquito Repellent and Distribution Method by Extracting Patchouli Oil

  • KWON, Woo-Taeg;KWON, Lee-Seung;YOO, Ho-Gil;LEE, Woo-Sik
    • The Journal of Industrial Distribution & Business
    • /
    • v.10 no.12
    • /
    • pp.15-23
    • /
    • 2019
  • Purpose : We will develop the distribution method of wide oil extract technology to develop repellent using this technology and study mosquito repellent persistence. Research design, data and methodology : A positive control group containing purified water, ethanol and picaridin was prepared, and the experimental control group was prepared in the same proportion as the positive control group, and 0.6% of broad oil was added. The results were summarized using the calculation method according to the avoidance effect and statistically tested by t-test using the excel statistics program. Results : Experiments on skin surface area and voice control of participants showed that men had 8.9% wider skin surface area than women, and voice control tests showed that women were bitten by mosquitoes five times more than men. Both the positive and the experimental control groups had a valid duration of up to three hours, but from the time of five hours, the positive control group had 77% and the experimental control had 90%, indicating a difference of 14.4% over the positive control group. Conclusions : The mosquito repellents developed in this study on the basis of safety and continuity are cost-effective in terms of mosquito repellent, and in addition fragrance, odor removal, perfume, ink, skin care and massage effect.