• Title/Summary/Keyword: friendly materials

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Study on Structural Analysis and Manufacturing of Polyethylene Canoes (폴리에틸렌 카누의 구조해석과 제조에 관한 연구)

  • Park, Chan-Kyun;Kim, Min-Gun;Cho, Seok-Swoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.3
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    • pp.309-316
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    • 2011
  • Canoes are usually made from wood or FRP. However, today environment-friendly materials are preferred, and hulls made of FRP are prohibited in some countries. Polyethylene can be recycled and so is suitable for synthetic canoe construction. We used 3D Boat-Design to determine the hydrostatic properties of the canoe. Flow-structure coupled analysis was performed using ANSYS Workbench R12.1. The hull pressure and passenger weight were considered as canoe loading factors. The key parameters for the canoe are the design variables. The constraints are as follows: (1) The maximum stress must not exceed 50% of the polyethylene yield stress; and (2) the canoe weight must not exceed 50 kg. The optimal structural conditions were obtained by the response optimization process. The components of the canoe hull were manufactured from polyethylene pipes and joined by thermal fusion methods. Tests showed that the polyethylene canoe had better performance than existing canoes.

Development of the Turnip Aphid, Lipaphis erysimi Kaltenbach (Homoptera: Aphididae), and Test of Insecticidal Efficacy of Some Commercial Natural Products

  • Kim, Dong-Young;Chang, Sung-Kwon;Jeong, Hyung-Uk;Kim, Min-Jee;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.16 no.2
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    • pp.93-99
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    • 2008
  • The turnip aphid is a worldwide pest, damaging mainly to crucifers. In order to understand the life parameters of Lipaphis erysimi for the eventual goal of control, the developmental periods, survival rates, lifespan, and fecundity of the species were investigated under five temperature regimes ($15^{\circ}C-35^{\circ}C$). Furthermore, the efficacy of several environment-friendly agricultural materials (EFAMs) that are on the market was subjected to test in order to obtain further accurate information. The developmental period of the turnip aphid nymph was longest at $15^{\circ}C$ as 16.9 days, shortened as temperature goes up to $25^{\circ}C$ (5.4 days), and then somewhat increased at $30^{\circ}C$ (5.9 days), suggesting that the most efficient temperature for nymphal development could be around $25^{\circ}C$. Mortality of the nymphal turnip aphid was obvious at $35^{\circ}C$, whereas it was minimal at other temperature schemes. The longevity of adults shortened as temperature goes up to $30^{\circ}C$. In particular, the maximum lifespan for adults continued for 55 days at $15^{\circ}C$, but shortened to 21 days at $30^{\circ}C$. The total fecundity was 35.7 at $15^{\circ}C$, 81 at $20^{\circ}C$, 64.2 at $25^{\circ}C$, and 6.6 individuals at $30^{\circ}C$, showing the highest fecundity at $20^{\circ}C$. After the turnip aphids were successfully stabilized in indoor environment the insecticidal activity was tested and mortality was determined 12, 24, 36, and 48 hrs after EFAMs are treated. Several on-the-market EFAMs showed more than 90% of insecticidal activity within 24 hrs or 48 hrs, but a few showed less than 90% activity, signifying importance of selection of proper EFAMs.

The Development of Eco-friendly Fiber Materials for Transport (수송용 친환경 섬유소재 개발)

  • Bok, Jin-Seon;Lee, Hyun-Seok;Jeong, Geung-Sik;Lee, Ki-Young;Park, Chang-Seok
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2012.03a
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    • pp.18-18
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    • 2012
  • 전 세계적으로 이산화탄소 배출량 저잠을 위해 모든 산업분야에서 연구개발의 중점을 두고 있다. 그의 일환으로 자동차 산업에서는 EU규제에 따라 리사이클이 가능한 소재 개발이 요구되고 있으며, 그중 많은 양이 사용되고 있는 PU Foam의 대체 재료 개발이 시급한 실정이다. 기존 자동차의 흡음재로 주로 사용되고 있는 PU Foam 소재는 통기성이 부족할 뿐만 아니라 연소 시 인체에 유해한 HCN Gas를 발생시키고, 한번 성형된 부품은 Recycle 및 Re-Use가 불가능하다는 단점이 있다. 또한 장시간 사용시 황변 발생과 악취가 발생하는 등으로 최근 대두되고 있는 자동차 내장재 감성품질 향상 측면에 한계를 나타내고 있다. 이러한 Low Melting 성능을 가지는 PET 부직포 소재의 한계를 극복하기 위하여 저융점 성능의 Elastic Fiber의 개발과 함께 고탄성 복합부직포 소재의 개발을 통해 높은 변형률과 우수한 복원력을 나타내는 환경친화형 열가소성 탄성체(Thermoplastic Elastomer) 개발을 추진하고 있다. 고탄성 복합부직포는 자동차 내장재 성형 시 열을 가하더라도 Elastomer 자체의 탄성 발현을 통해 초기의 Bulky성을 유지할 수 있으며, Recycle 및 Re-use가 가능하여 환경 친화적인 측면에서도 큰 장점을 갖고 있다. 자동차용 흡음 내장재뿐만 아니라 각종 수송용 차량의 경량화 및 쾌적성 향상을 위한 용도로써 자동차 내장용 PU Foam의 57% 이상을 차지하고 있는 Seat Cushion재 등의 대체가 가능하며, 다양한 산업분야에서 사용되고 있는 PU Foam의 대체로 다양한 용도 전개가 가능할 것으로 예상된다. 본 연구에서는 PU Foam의 대체 재료로 각광받고 있는 Elastic PET를 개발하여 자동차 내장재로의 적용 가능성을 검토하였다.

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Material Stability Assessment of Low Oxygen and Heating Treatment (저산소 및 열처리법에 대한 문화재 재질 안정성 평가)

  • Jang, Han Gyeol;Baek, Na Yeon;Kang, Dai Ill
    • Journal of Conservation Science
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    • v.30 no.2
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    • pp.149-156
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    • 2014
  • Low oxygen treatment and heating treatment are used to prevent insects in the field of food science. These eco-friendly control methods can be applied to biological control technique in conservation treatment of organic cultural properties. To evaluate material stability, low-oxygen treatment and low oxygen treatment are applied to wood, pigment, paper and textile that are related to historical wooden buildings. As a result, wood moisture content declined after low oxygen treatment. But decline rate is a little, so it can be expected to turn back original state as time passes. And test result on pigment, paper, textile of chrominance and strength of test materials are stable. But after heating treatment, pigments are separated.

Images of Hospital Emergency Medical Technicians Perceived by Emergency Medical Service Providers (Focusing on tertiary medical institutions in Daejeon and Chungcheongnam do) (응급의료종사자가 인식하는 병원 내 응급구조사의 이미지 (대전, 충남 3차의료기관 중심으로))

  • Han, Song-Yi;Bae, Ki-Sook;Kim, Jin-Uk
    • The Journal of the Korea Contents Association
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    • v.12 no.4
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    • pp.373-379
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    • 2012
  • This study surveyed the image of hospital emergency medical technicians with 122 emergency medical service providers (doctors and nurses) working at tertiary medical institutions in Daejeon and Chungcheongnam.do in order to provide basic materials for enhancing the status and professional image of hospital emergency medical technicians. According to the results of this study, the overall image was $3.27{\pm}0.34$, and by its sub.area, professional image was highest and role image was lowest. By item, 'Maintain a friendly relations with doctors' was highest, and 'Arrogant and negligent in job performance' was lowest. In order to enhance their image, hospital emergency medical technicians need to assume a sincere attitude toward patients and colleagues consistently, to strengthen their professionalism, and to carry out their duties and roles faithfully. What is more, the association should take proper measures and to establish the sound image of emergency medical technician as a professional through active campaigns and monitoring using mass media.

A Study on the Citation Analysis of Scholarly Journal in the Field of Life Science (생명과학 학술지의 인용 분석 연구)

  • Kim, Hong-Ryul
    • Journal of the Korean Society for information Management
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    • v.22 no.3 s.57
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    • pp.85-102
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    • 2005
  • The purpose of this study is to analysis the type of cited materials, dependence ratio of foreign information of domestic researchers, and to predicts half-life of life science for the collection development of libraries and user friendly information services. The journal articles was extracted from five subjects-medical science, pharmacy, food science, agricultural science, microbiology. In result, it was found that it citing the scholarly journal most plentifully, and dependence ratio of foreign information of domestic researchers was high most the microbiology. And then, half-life of life science was found 8.98 in agricultural science, and 7.11 in food science, and 6.96 in pharmacy, and so on.

Preparation and Coating of Red Colored Artificial Pearl by CVD Method (CVD법을 이용한 적색 인조진주 코팅 및 제조)

  • Shin, Cheol-Woo;Choi, Kyoung-Rim;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.3
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    • pp.857-864
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    • 2018
  • Demand for developing artificial green pearl that meets the needs of modern people has been increasing. In this paper, eco-friendly inorganic pearlescent pigment was used instead of organic pigment and urethane resin was substituted for nitrocellulose which has been used as main materials in previous preparation method, increasing gloss from 73.4% to 86.7%. Urethane was coated on substrate before finishing with CVD, resulting high gloss of 96%. Colorimeteric analysis shows that a* and b* of CIE value was changed from +37.7 and +24.5 to +31.9 and +14.2 respectively because of CVD finishing, obtaining colorful, high gloss and durable artificial pearl. Quality and toxicity of samples was established by chemical resistance, glossiness, colorimeter, surface roughness, wear resistance, content of heavy-metal, and salt water test.

Identification of Anti-Cancer Targets of Eco-Friendly Waste Punica granatum Peel by Dual Reverse Virtual Screening and Binding Analysis

  • Usha, Talambedu;Goyal, Arvind Kumar;Lubna, Syed;Prashanth, H.P.;Mohan, T. Madhan;Pande, Veena;Middha, Sushil Kumar
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10345-10350
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    • 2015
  • Background: Punica granatum (family: Lythraceae) is mainly found in Iran, which is considered to be its primary centre of origin. Studies on pomegranate peel have revealed antioxidant, anti-inflammatory, anti-angiogenesis activities, with prevention of premature aging and reducing inflammation. In addition to this it is also useful in treating various diseases like diabetes, maintaining blood pressure and treatment of neoplasms such as prostate and breast cancer. Objectives: In this study we identified anti-cancer targets of active compounds like corilagin (tannins), quercetin (flavonoids) and pseudopelletierine (alkaloids) present in pomegranate peel by employing dual reverse screening and binding analysis. Materials and Methods: The potent targets of the pomegranate peel were annotated by the PharmMapper and ReverseScreen 3D, then compared with targets identified from different Bioassay databases (NPACT and HIT's). Docking was then further employed using AutoDock pyrx and validated through discovery studio for studying molecular interactions. Results: A number of potent anti-cancerous targets were attained from the PharmMapper server according to their fit score and from ReverseScreen 3D server according to decreasing 3D scores. Conclusion: The identified targets now need to be further validated through in vitro and in vivo studies.

Effects of Polyurethane Coatings on 304 Stainless Steel Formed by Thermoset for Safety Management of Industrial Disaster (산업 재해의 안전관리를 위한 열경화에 의한 304 스테인레스 스틸에 대한 폴리우레탄 도료의 영향)

  • Kim, Ki-Jun;Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.2
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    • pp.317-322
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    • 2012
  • The microstructures were examined by SEM, FT-IR spectra, tensible properties mole % of [NCO/OH], and particle size analyzer. Growing concerns in the environment-friendly industries have led to the development of solvent-free formulations that can be cured. We had synthesized the polyurethane resin having the ability to protect stainless steel against corrosion. Compared with general packing materials and coatings, this resin is highly stronger in intensity and longer durability. Polyurethane resins were composed of polyols, IPDI, silicone surfactant, catalyst and crosslink agent. Moreover, thermal fillers such as $Al_2O_3$, fume silica and $ZrO_2$ not only accelerated the curing rate but also improved the physical property as thermal barriers. The rigid segments of polyurethane in mechanical properties were due to crosslink agent and the increase of [NCO/OH]. In conclusion, the polyurethane microstructure with crosslink agent can be good material for themoset coating of metal substrates such as stainless steel.

Antimicrobial Activities of Sophorolipids and Its Application for Cosmetics (Sophorolipid의 항균효과와 화장품에의 응용)

  • Cho, Wan-Goo;Park, Hyo-Soon;Ahn, Byoung-Joon
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.34 no.4
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    • pp.317-323
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    • 2008
  • Some surfactants known as biosurfactants, are produced biologically by yeast and bacteria from various substances. They are more effective and environmentally friendly than many other synthetic surfactants. Antimicrobial activities of sophorolipids produced by Candida bombiocola were investigated against various microorganisms. Minimal Inhibitory concentration (MIC) of sophorolipid against S. mutans, C. xerosis, and P. acnes were 0.005, 0.05, and 0.005%, respectively. The antimicrobiological activities were more effective than those of SLS and APG. Skin exfoliating and moisturizing effects of vehicles with the sophorolipids were tested. The skin turnover time of aqueous solution with 0.25% sophorolipids was similar to that of aqueous solution with 5.0% lactic acid. Higher moisturizing effects on skin showed as the concentration of sophorolipids increased. We suggest that the sophorolipids can be used for cosmetics as an antimicrobiological agent and an active materials of skin moisturizing and exfoliating.