• Title/Summary/Keyword: contact effect

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Acaricidal Abilities and Chemical Composition of Forsythia suspense Fruit Oil against Storage and Pyroglyphid Mites

  • Lee, Hwa-won;Lee, Hoi-Seon
    • Journal of Applied Biological Chemistry
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    • v.58 no.2
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    • pp.105-108
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    • 2015
  • This research is aimed at evaluating the potential abilities of the natural acaricide of F. suspense oil against Tyrophagus putrescentiae and Dermatophagoides spp. Based on the $LD_{50}$ values, in contact bioassay, F. suspense oil (8.19, 3.28, and $4.35{\mu}g/cm^2$) showed acaricidal effects against T. putrescentiae, D. farinae, and D. pteronyssinus, respectively. Fumigant toxicities of F. suspense oil showed similar patterns as those observed with contact toxicities. GC/MS analysis showed the major components of F. suspense oil to be ${\beta}$-pinene (45.88%), myrtenol (13.86%), (+)-${\alpha}$-pinene (13.09%), (-)-trans-pinocarveol (7.34%), sabinene (6.64%) and pinocarvone (4.13%). These findings indicate that F. suspense oil has potential as a natural acaricide.

Analysis of Surface Fibers by Wavelet Transform and Subjective Evaluation of Wool Fabrics (웨이블릿 변환을 이용한 모직물의 표면섬유 분석과 주관적 감각 평가)

  • 김동옥;김은애;유신정
    • Science of Emotion and Sensibility
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    • v.5 no.3
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    • pp.53-59
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    • 2002
  • The surface fibers on the fabric is one of decisive factors which affects human sensory evaluation as well as heat and moisture transfer characteristics. In this study the length and distribution of surface fibers that are extruded from the fabric surface of the wool/wool blend fabrics (14 wool fabrics and 10 wool blend fabrics) and its contribution to subjective sensory evaluation were investigated. In order to quantify the length and distribution of surface fibers, image analysis and wavelet transform technique were introduced. Instant warm-cool feeling of touch, Q$\_$max/, and contact area were also measured and related to the quantified surface fibers. To figure out the effect of surface characteristics on sensory evaluation, human sensory responses to three adjectives which represent surface characteristics and warm-cool feeling of touch were obtained and analyzed. The relationship between the quantified surface fibers assessed by wavelet energy and both warm-cool reeling of touch, Qmax, and human sensory response were discussed.

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A Study on the Technical Change and Maternal Touch in Child Care (보육 산업의 발달과 아동의 모성접촉으로부터의 소외)

  • Kim, Sung-Hee
    • Korean Journal of Human Ecology
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    • v.19 no.6
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    • pp.933-943
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    • 2010
  • This study was carried out to investigate the effect of changes in child care technology on mother-child contact by using all sorts of literature such as diaries, documents or statistical data. Child care technologies began to change during the 1960's. Diverse goods and services such as baby dry milk, paper diapers and child care centers have made child care easier and saved a great deal of time. This has also allowed women to participate in labor markets easily despite rearing children. But maternal contact with children have declined due to new goods and services and this trend is especially prevalent in early childhood. It could be supported that the convenience of rearing rather than the needs of children like as attachment to maternity primarily was considered in technological change. From this results it was suggested that we should develop the alternative child care technologies which better reflect children's needs.

Study of Tool Surface Texture Directionality Effect on Frictional Behavior of Sheet Metal Forming (금형 표면 거칠기의 방향성이 판재의 마찰 특성에 미치는 영향 연구)

  • Han, S.S.
    • Transactions of Materials Processing
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    • v.29 no.2
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    • pp.113-117
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    • 2020
  • Various parameters are involved in the frictional behavior of steel sheet during stamping. We performed various tests in order to investigate the influence of tool surface texture directionality upon the resulting friction in sheet forming processes. Four different tools were manufactured which gave us a range of roughness for both parallel and transverse texture directions. Each of the tools was examined in flat type friction tests under identical test conditions. The tool with the transverse surface texture produces significantly lower levels of friction than the tool with parallel texture direction. Considering the lubrication mechanism associated with transverse texture, one can imagine the lubricant being constantly supplied from the reservoir of the micro valley to the point of contact and hence producing the lower levels of friction seen.

Micro/Nano Rheological Characteristics of PMMA in Hot Embossing Process (핫엠보싱 공정에서 PMMA의 마이크로/나노 레올로지 특성)

  • Kim B. H.;Kim K. S.;Ban J. H.;Shin J. K.;Kim H. Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.05a
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    • pp.259-264
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    • 2004
  • The hot embossing process as a method for the fabrication of polymer is becoming increasingly important because of its simple process, low cost, high replication fidelity and relatively high throughput. In this paper, we carried out experimental studies and numerical simulations in order to understand the viscous flow of polymer film during hot embossing process. As the initial step of quantitating the hot embossing process, simple parametric studies for the embossing conditions have been carried out using high resolution masters which patterned by DRIE process. Under different embossing times and pressures, the viscous flow of PMMA films into micro/nano cavities has been investigated. Also, the viscous flow during the hot embossing process has been simulated by the continuum based FDM analysis considering micro/nano effect, such as surface tension and contact angle.

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The Effect of Ethanol Administration on The Immune Response of Mice (에타놀투여가 마우스의 면역반응에 미치는 영향에 관한 실험적 연구)

  • 김금재
    • Journal of Korean Academy of Nursing
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    • v.21 no.1
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    • pp.5-15
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    • 1991
  • The present study was undertaken in an effort to investigate the effects of alcohol on survival of mice and on their humoral and cellular immune responses, The immune responses examined were Arthus and delayed-type hyperrsnesitivity(DTH) reactions to sheep red blood cells(SRBC), contact hypersensitivity to dinitrofluorobenzend(DNFB), antibody response to thymus - dependent SRBC and to thymus -independent polyvinylpyroridone(PVP), and the recovery of Crytococcus neoformans from the liver, spleen, kidney and brain of experimentally infected mice. The administration of ethanol concentrations of 20% or less did not cause any change in survival rates as compared withs saline injected control group. In general, ethanol administration inhibited the Arthus and DTH reactions to SRBC, contact hypersensitivity to DNFB, and antibody response to both SRBC and PVP and it also decreased the resistance of mice to C. neoformans infection. Taken together, the present study stongly suggested that ethanol inhibits immune response and decrease the resistance of mice to C. neoformans infection.

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A study of joining method of BSCCO(2223) tape (Bi-2223초전도 선재의 접합공정 연구)

  • 김정호;김태우;주진호;서수정
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 1999.02a
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    • pp.18-21
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    • 1999
  • The effects of joining process such as contact method, shape of joined area and pressure on the properties of Bi-2223 superconducting tape have been optimized. In the process tapes were etched to expose the superconductor core in the shape of 'ㅁ' and 'ㄷ'. The exposed cores of the two tapes were brought into contact, uniaxially pressed and sintered. Subsequently, the current capacity of the joined tape was measured as a function of uniaxial pressure. It was observed that the current capacity was significantly dependent on uniaxial pressure. The joined tape, fabricated with a pressure of 1,600 MPa, showed the highest value of current capacity(90%) of highest value of current capacity is resulted from improvements in core density, contacting area and grain alignment, etc. In addition the effect of processing variables on microstructural evolution and mechanical property of joined tape will be presented.

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Hydroelastic Effects in Vibration of Plate and Ship Hull Structures Contacted with Fluid

  • Lee, Jong-Soo;Song, Chang-Yong
    • International Journal of Ocean System Engineering
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    • v.1 no.2
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    • pp.76-88
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    • 2011
  • The present study deals with the hydroelastic vibration analysis of structures in contact with fluid via coupled fluid-structure interaction (FSI) embedded with a finite element method (FEM) such that a structure displacement formulation is coupled with a fluid pressure-displacement formulation. For the preliminary study and validation of FEM based coupled FSI analysis, hydroelastic vibration characteristics of a rectangular plate in contact with fluid are first compared with the elastic vibration in terms of boundary condition and mode frequency. Numerical results from coupled FSI analysis have been shown to be rational and accurate, compared to energy method based theoretical solutions and experimental results. The effect of free surface on the vibration mode is numerically studied by changing the submerged depth of a rectangular plate. As a practical application, the hull structural vibration of 4,000 twenty-foot equivalent units (TEU) container ship is considered. Hydroelastic results of the ship hull structure are compared with those obtained from the elastic condition.

Enhanced hole injection by oxygen plasma treatment on Au electrode for bottom-contact pentacene organic thin-film transistors

  • Kim, Woong-Kwon;Hong, Ki-Hyon;Kim, Soo-Young;Lee, Jong-Lam
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.74-77
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    • 2006
  • Thin $AuO_x$ layer was formed by $O_2$ plasma treatment on Au electrode. The surface work function of plasma treatment showed higher by 0.5 eV than that of bare Au, reducing the hole injection barrier at the Au/pentacene interface. Using $O_2$ plasma-treated Au source-drain electrodes, the field-effect mobility of bottom-contact pentacene-OTFT was increased from 0.05 to 0.1 $cm^2/Vs$.

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Electrostatic Electrification Properties due to Square of Silicone Rubber (실리콘 고무의 면적 변화에 따른 정전기 대전 특성)

  • Lee, Sung-Ill
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.9
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    • pp.732-737
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    • 2012
  • This study made a specimen (contact surface size: $45\;mm{\times}0.02\;mm{\times}45{\sim}55\;mm$) with silicon rubber for low voltage cable with 50 phr silica filler. The electrification voltage of electrostatics were measured for different sizes of contact surface with the applied voltage of 10kV and the environmental settings of temperature ($25{\sim}40^{\circ}C$) and humidity (40~80%). The following conclusions were made. The electrification voltage of electrostatics decreased as the humidity increased. The electrification voltage of electrostatics increased as the temperature increased. The larger the surface size, the higher the electrification voltage of electrostatics. The property of the material had more effect on the relaxation time than the humidity.