• 제목/요약/키워드: water-resistant

검색결과 677건 처리시간 0.03초

Studies on the Water Resistance Properties of the Polyurethane Foam Silicone Foal Control Agent according to the Type of Silicone Foam Stabilizer (실리콘 정포제의 종류에 따른 폴리우레탄 폼 지수제의 내수성 특성에 관한 연구)

  • Kim, Keun-Hur;Kim, Hyun-Min;Kim, Sung-Rae;Kim, Young-Geun
    • Journal of the Korea institute for structural maintenance and inspection
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    • 제20권2호
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    • pp.60-66
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    • 2016
  • Polyurethane foam index a of the cell structure and the absorption change by using the foam stabilizer of six to investigate the polyurethane foam index producing the agent to the siloxane analyzed with silicon foam stabilizer with FE-SEM in accordance with the characteristics of the silicon-based foam stabilizer cell structure of the primary DC-193 on the chain ends is PO n dog bond, DC-2585, DC-5125, DC-198 has been confirmed as a close cell, silicone surfactant is combined EO n dog to a siloxane main chain terminus DC-5043 and DC-5598 that appeared to open cell structure. In addition, most absorption of the DC-5043 appeared was the size of the open cell greatest formed by the absorption of the cell structure change this absorption of the size of the close cell most detailed and uniform DC-193 appeared small household water-resistant best many showed. The performance test of the water was found to be excellent.

Evaluation of Safety for the Supplement of Herbicide-resistant Rice in Old Male Rats (노령기 흰쥐에서 제초제 저항성 쌀의 급여에 대한 안전성 평가)

  • 이성현;박홍주;조소영;전혜경;박용환
    • Journal of the Korean Society of Food Science and Nutrition
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    • 제33권5호
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    • pp.810-814
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    • 2004
  • This research was conducted to evaluate the safety of the herbicide-resistant rice, a genetically modified organism (GMO) developed by the Rural Development Administration by exposing it to 12 months old Sprague-Dawley rats for 8 weeks. The composition of herbicide-resistant brown rice with/without heating treatment was compared with those of conventional Ilpum brown rice with/without heating treatment to assess composition equivalence. Compositional analysis was performed to measure proximates, fiber, and minerals. The nutritional components of herbicide-resistant rice were similar to those of the nontransgenic control or were within the normal range of nontransgenic rice. Four groups of experimental male rats were fed one of the following diets for eight weeks: Ilpum brown rice (I) and its heated rice (IH) as non-GMO, and herbicide-resistant brown rice (G) and its heated rice (GH) as GMO- We checked clinical symptoms (anorexia, salivation, diarrhea, polyuria, anuria, fecal change), food intake, and water consumption every day, change of body weight once a week, and serum biochemistry and organ weights after 8 weeks of experimental feeding We did not find any significant differences in the above-mentioned items. These results suggested that genetically modified herbicide-resistant rice was compositionally equivalent to conventional Ilpum rice, and nutritional characteristics and safety of herbicide-resistant rice in old male rats treated for 8 weeks were not different from those of Ilpum rice, non-GMO.

Comparison of the Properties of Wheat Flours Supplemented with Various Dietary Fibers

  • Lee, Hyun-Ju;Shin, Mal-Shick
    • Food Science and Biotechnology
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    • 제15권5호
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    • pp.746-751
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    • 2006
  • The effects of resistant starch (RS) and non-starch polysaccharide (NSP) addition on the properties of hard wheat flour were investigated. Total dietary fiber (TDF) levels of various NSP ranged from 78.3-100.0%, but TDF and RS levels of autoclaved RS3 and cross-linked RS4 were 16.1 and 35.0% and 13.2 and 90.9%, respectively. DF-supplemented flour increased swelling power, but RS4-supplemented flour exhibited the lowest it. Solubility increased with the addition of pectin and RS3, but decreased with the addition of cellulose and RS4. RS-supplemented flour had increased lightness (L), but decreased values of redness (a) and yellowness (b). RS3 and pectin increased the dough development time, but RS4, cellulose, and chitosan decreased it. The water absorptions of pectin- and RS4-supplemented flours increased, however the dough stability decreased. The initial pasting temperatures of RS- and NSP-supplemented flours increased regardless of amount added, but the maximum peak viscosity decreased for all except the pectin-supplemented flour.

Antibacterial Activity of Antimycotic Miconazole against Methicillin-Resistant Staphylococcus aureus

  • LEE, SANG-HWA;CHANG-JIN KIM
    • Journal of Microbiology and Biotechnology
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    • 제9권5호
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    • pp.572-575
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    • 1999
  • Miconazole was estimated to have a minimum inhibitory concentration of 0.78 ㎍/㎖ against the methicillin-resistant strains of Staphylococcus aureus (MRSA). The antibacterial activity of miconazole against MRSA was bacteriostatic in cation-adjusted Mueller-Hinton broth, but bacteriocidal in saline solution. The anti-MRSA activity of miconazole did not show a significant change under the susceptibility-testing conditions such as various inoculum sizes, pHs, or cations (Ca/sup ++/ or Mg/sup ++/) which was added to the medium. However, the anti-MRSA activity of miconazole was completely suppressed by lipophilic a-tocopherol (50 ㎍/㎖), but definitely not by water-soluble ascorbic acid.

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Conditions of kimchi to be safe from consuming viable Ascaris suum eggs (학술 2 - 김치에 함유된 돼지회충란의 사멸조건)

  • Shin, Sung-Shik
    • Journal of the korean veterinary medical association
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    • 제48권9호
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    • pp.540-543
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    • 2012
  • Livestock excretes are frequently used in organic farming to produce vegetables and crops. However, zoonotic parasite eggs can be contaminated into such products and people can be infected with parasites of animal origin. Sporadic zoonotic infections with Ascaris suum have been reported even in developed countries, such as North America, Denmark, and the United Kingdom. Ascaris eggs are resistant to most adverse environmental conditions, and pigs and humans become infected by ingestion of fecally excreted eggs through contaminated food, water, or soil. This article discusses the resistant nature of ascarid eggs against harsh environment, and conditions of kimchi to be safe from consuming viable A. suum eggs.

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High Strength Low Alloy Steel for Sour Service

  • Jung, Hwan Gyo;Kim, Sang Hyun;Yang, Boo Young;Kang, Ki Bong
    • Corrosion Science and Technology
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    • 제7권5호
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    • pp.288-295
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    • 2008
  • The increase use of natural gas as an energy source has been continuous demand for ever-increasing strength in gas transmission pipeline materials in order to achieve safe and economic transportation of natural gas. In particular, linepipe material for sour gas service primarily needs to have crack resistant property. However, applications of sour linepipes are expanding toward deep water or cold region, which require higher toughness and/or heavier wall thickness as well as higher strength. To improve the crack resistance of linepipe steel in sour environment, low alloy steel are produced by controlled rolling subsequently followed by the accelerated cooling process. This paper summarizes the design concepts for controlling crack resistant property low alloy linepipe steels for sour gas service.

An Experimental Study on the Anti-corrosion and Anti-wear Characteristics of MoS$_2$ Bonded Films for Automotive Wheel Joints (방청 및 내마모 특성이 향상된 자동차 휠 조인트용 $MoS_2$계 고체 피막 윤활제)

  • 한흥구;공호성;윤의성;권오관
    • Tribology and Lubricants
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    • 제16권3호
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    • pp.173-181
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    • 2000
  • Friction, wear and corrosion characteristics of various MoS$_2$ bonded film lubricants were investigated to apply them to automotive wheel joints. MoS$_2$ bonded film lubricants were formulated by combinations of several additives and binders, and they were coated onto the pre-treated surfaces of specimens. Friction and wear characteristics were evaluated with Falex pin & vee-block test and LFW-1 block-on-ring test. For the corrosion resistant characteristics of the films, salt solution spray corrosion tests were performed. Results showed that MoS$_2$ bonded films containing both inorganic and organic corrosion-resistant additives yielded a synergy effect on anti-corrosion resistance. Also, binders having the better water-proof and thermal stability showed the lower friction and higher corrosion resistance.

Antimicrobial Activities of Scutellaria baicalensis and Phellodendron amurense Against MRSA and Candida (황금과 황백 추출물의 MRSA와 Candida에 대한 항균활성)

    • Korean Journal of Microbiology
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    • 제40권1호
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    • pp.17-22
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    • 2004
  • Scutellaria baicalensis and Phellodendron amurense, which have been used traditionally in treatment of many kinds of illness including infectious diseases, were extracted with hexane, dichloromethane, methanol and water, respectively and serially. Antimicrobial activities of the extracts were examined by disk diffusion method. Methanol extract from Scutellaria baicalensis revealed high antimicrobial activities against MRSA, Gm-bacteria and Candida albicans, dichloromethnane extract from Phellodendron amurense showed lower activity than the extract of Scutellaria baicalensis. Results suggest that methanol extract from Scutellaria baicalensis could be one of the candidates for new antimicrobial agent against the antibiotic-resistant microorganisms by further steps for the purification, determination of structure and synthesis.

Distribution Characteristics and Antibiotics Resistance of Enterococcus spp. in Nakdong River (낙동강에서 엔테로코커스의 분포특성 및 항생제별 내성률)

  • Seong, Jin-Uk;Cha, Soon-Bae;Ryu, Kwang-Hyun;Choi, Kwang-Soon;Park, Je-Chul
    • Korean Journal of Ecology and Environment
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    • 제46권3호
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    • pp.360-366
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    • 2013
  • This study was it conducted on effluent or river water close to discharge locations from a treatment plant, which were analyzed for the presence, phenotype and antibiotic resistance rates of Vancomycin Resistant Enterococci (VRE). The test results for isolation and identification of Enterococcus spp. showed that they all were VRE positive, with a total of 32 strains detected. Multiplex PCR was conducted for 32 strains, each of which were identified as E. faecium, and the results indicated that they were all confirmed as VRE, corresponding to the Van A phenotype. The results of E. faecium concentrations measured at various locations indicated that they were, on average, higher at the location of sewage treatment plants. The frequency of positive tests as well as the number of colonies was higher downstream of treatment plants. The minimum inhibitory concentration was inspected for 26 strains of discharged water samples from sewage water treatment plants, and 6 strains of river samples. Out of 19 antibiotics, 14 and 5 species showed resistance and sensitivity, respectively.

Performance analysis of OFDM and CDMA communication methods in underwater acoustic channel (수중 채널 환경에서 OFDM 및 CDMA 통신 방식별 성능 분석)

  • Kim, Kil-Yong;Kim, Min-Sang;Ko, Hak-Lim;Im, Tae-Ho
    • The Journal of the Acoustical Society of Korea
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    • 제38권1호
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    • pp.30-38
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    • 2019
  • In recent years, researches on various communication methods have been conducted, particularly on OFDM (Orthogonal Frequency Division Multiplexing) and CDMA (Code Division Multiple Access) methods, as the use of underwater communication increases. While OFDM is, in general, advantageous in that it is resistant to Doppler in the water and it enables a high-speed communication, CDMA is resistant to frequency selective fading in the water and it can reduce energy consumption. Therefore, in this paper, we performed experiments in the shallow water in Western Sea of Korea to analyze the performance of OFDM and CDMA communication systems in the underwater channel environment. The maximum delay spread and Doppler spread were drawn by using the data obtained from the real sea area in order to analyze the underwater channel environment characteristics of the shallow water in Western Sea of Korea. The communication performances of OFDM and CDMA are shown as coded BER (Bit Error Rate) according to the variation of the maximum delay spread and the Doppler spread, respectively. The result of the analysis show that the OFDM method has more resistant performances to the underwater channel environment changes than the CDMA method.