• Title/Summary/Keyword: Strength decrease

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Analysis of Fundamental Properties of Cement Mortar with Change of Solid Contents of PC Type Water Reducing Agent (PC계 감수제의 고형분율 변화에 따른 시멘트 모르타르의 기초적 특성 분석)

  • Kim, Min-Sang;Moon, Byeong-Yong;Lee, Jae-Jin;Lee, Jea-Hyun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.22-23
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    • 2017
  • This research aimed to analyze the fundamental properties of cement mortar accompanying the change of solid contents of PC type water reducing agent. As a result of the experiment, in the case of flow to the properties of the fresh mortar, it shows a tendency to decrease as the solid content ratio decreases, and the decrease width with the passage of time is greatly reduced when 30 minutes passed since the passage of 60minutes It turned out that it was. In the case of the air contents and the compressive strength, it was found that there is almost no difference due to the change in the solid contents.

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The Lungs' Real-time States are Reflected in the Tissue at its Related Acupuncture Points

  • Kovich, Fletcher
    • Journal of Acupuncture Research
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    • v.36 no.2
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    • pp.88-91
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    • 2019
  • Background: The intelligent tissue hypothesis on how acupuncture works, states that real-time organ states are reflected in the tissue at an organ's related acupuncture points (acupoints). Any such changes in the tissue would produce corresponding changes in the impedance at those locations. Methods: To test this hypothesis in relation to the lungs, the impedance at key lung-related acupoints was monitored in real time while the patient breathed normally, then breathed deeply, then quickly, then held his breath. Results: When breathing deeply this produced a notable decrease in the impedance at 1 acupoint, while breathing quickly produced a decrease at another acupoint, suggesting that these different functions taxed different aspects of the lungs, which was then reflected at different acupoints. The impedance at all the acupoints also contained low-amplitude waves that reflected the base rate of the respiration pacesetter, and the amplitude of these waves also varied to reflect different real-time states in the lungs. Conclusion: These real-time impedance patterns suggested that corresponding physical patterns were present in the tissue at these acupoints, and these physical patterns mirrored the real-time variations in function strength of the related organ (the lungs). These results were consistent with the hypothesis.

A study on the quality improvement plan of recycled aggregate concrete for the use of building materials (건축자재 활용을 위한 순환골재 콘크리트의 품질개선 방안 연구)

  • Kim, Tae-Hyun;Hong, Sung-In;Choi, Yun-Jeong;An, Jae-Hong
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.04a
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    • pp.162-163
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    • 2022
  • Recycled aggregate has structural limitations in that it cannot be actively used for use as a structural building material due to quality deviations such as increase in cracks, decrease in constructability during in-situ casting, and decrease in strength. Although the government gives incentives to use recycled aggregate concrete for major structural parts of buildings to revitalize recycled aggregate concrete, there is a perception that the quality control of recycled aggregate producers that produce raw materials is insufficient. In this study, recycled aggregate, I checked the quality of the company that handles the quality. We are working on this.

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EO Characteristics in the Vertical Alignment (VA)-$\pi$ mode LCD Using the Tilt Angle Decrease Effect on the Blended Polymer (혼합된 polymer에서의 틸트 감소 효과를 이용한 VA-$\pi$ mode LCD의 전기광학 특성)

  • Lee, Kyung-Jun;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05d
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    • pp.53-56
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    • 2003
  • Blending effects for generating a pretilt angle in nematic liquid crystal (NLC) with negative dielectric anisotropy on the blended polyimide (PI) of homeotropic and homogeneous alignment surface were studied. Also, we investigated the EO performances for the advanced VA-$\pi$ cell using this homeotropic blended PI surface. A many decrease of tilt angle on the polymer surface to blend homeotropic PI and homogeneous PI with side chain type was measured, and the tilt angle decreased as blended ratio and rubbing strength increase. The blended effects for generating a pretilt angle were clearly observed, and the many decrease of tilt angle can be achieved by using the blended PI surface. The electro-optical (EO) characteristics using the advanced VA-$\pi$ cell using the homeotropic blended PI surface than that of conventional VA cell can be improved. We suggest that the developed advanced VA-$\pi$ cell on a homeotropic blended PI surface is a promising technique for the achievement of a fast response time, and a high contrast ratio.

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The Mechanical Propertis of Wool-like Fabrics Using Composite Textured Yarn (복합가공사를 이용한 Wool-like 직물의 역학적성질)

  • Park, Myung-Soo;Yoon, Jong-Ho
    • Fashion & Textile Research Journal
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    • v.5 no.4
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    • pp.408-412
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    • 2003
  • The micro structure of POY was modified and a wool-like touch yarn of composite fibers with different shrinkage was made. With this yarn 12 different fabrics with wool like touch were prepared. The characteristic physical property changes of the fabrics examined are as follows: 1. In all cases, the initial high shrinkage stages were observed in hot water treatment and the 3D images of complex multilayer of typical doubling fibers with different shrinkage were also observed in hot air treatment of 170C. 2. The tensile strength changes of satin and plain fabrics with the change of twist count showed similar behavior. However, WT's were slightly higher and RT's was lower in twill and satin fabrics than those in plain fabric. 3. Since a slight decrease of B's of twill fabric found with increasing twist count under given experimental condition, it could be influenced on the anti-drape stiffness was decreased and flexibility was increased. 4. A significant decrease of G values was observed in the twist count 800-1000 T.P.M However, in the twist count higher than 1000 T.P.M G values observed were kept nearly constant. 5. MIU of plain and twill fabrics showed a drastic decrease at the twist count higher than 1000 T.P.M.

Simultaneous Forbush Decrease caused by a CME shot by the STEREO

  • Oh, Su-Yeon;Yi, Yu
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.80.2-80.2
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    • 2011
  • The sudden decrease of galactic cosmic ray (GCR) intensity observed by ground neutron monitor (NM) is called a Forbush decrease (FD) event. The intensity time profile of FD event looks like the geomagnetic storm visualized by geomagnetic storm index Dst. Oh et al. [2008] and Oh and Yi [2009] classified the FD events into two kinds by criteria of the overlapping simultaneity of main phase in universal time (UT). The FD event is defined simultaneous if the main phase parts observed by the stations distributed evenly around the Earth are overlapped in UT and non-simultaneous if ones are overlapped in each station's local time (LT). They suggested the occurrence mechanisms of two kind FD events related to the interplanetary magnetic structures such as the interplanetary shock (IP shock) and magnetic cloud. According to their model, the simultaneity of FD depends on the strength and propagation direction of interactive magnetic structures overtaking the Earth. Now the STEREO mission can visualize the emergence and propagation direction of the coronal mass ejection (CME) in 3-dimension in the heliosphere. Thus, it is possible to test the suggested mechanisms causing two different types of FD events. One simultaneous FD observed on February 17, 2011 may be caused by a CME heading directly toward the Earth observed on February 15, 2011 by the STEREO mission. The simultaneity of FD event is proved to be a useful analysis tool in figuring out the geo-effectiveness of solar events such as interplanetary CMEs and IP shocks.

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A Study on Accident Pattern of Distributing Cable Termination Considering PL Law Environment (PL법 환경을 고려한 배전 케이블 종단부의 사고 유형 연구)

  • Baek, Seung-Myeong;Choi, Jae-Hyeong;Choi, Jin-Wook;Kim, Young-Seok;Kim, Sun-Gu;Kim, Sang-Hyun
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.10a
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    • pp.319-322
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    • 2008
  • This paper introduces experimental investigates of an accident pattern for the distributing XLPE cable terminations considering PL law environment. The influence of defects such as thickness and length decrease of XLPE, the impurity on XLPE and the gap between stress-con of housing and semi-conductor on insulating properties of the termination have been studied. The thickness and length decrease of XLPE decrease ac breakdown strengths. Dielectric breakdown traces of XLPE that is damaged by knife displayed other shape. The gap of between housing and semiconductor deteriorates dielectric strength of XLPE seriously.

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An Analysis on the Protection Mechanism of Some Inert Reactive Cassettes (비활성 요소의 방호 메커니즘 분석)

  • Joo, Jae-Hyun;Choi, Joon-Hong;Lee, Heon-Joo;Lee, Chang-Hyun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.5
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    • pp.550-556
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    • 2012
  • In this study, a series of ballistic experiments have been performed to investigate the protection mechanism of some inert reactive cassettes against shaped charge jet. Three kinds of material were tested as a core material of the inert cassettes, i.e. one of rubber materials, a high modulus and high strength composite material used for ballistic protection and a mixture of energetic materials. Parameters such as deformation of the cassettes, occurrence time of jet distortion, leading jet length and residual penetration depth were investigated from the experiments and they were compared to each other quantitatively according to the jet incidence angles. The results show that the increment of cassette deformation caused jet distortion to occur early and jet distortion brought decrease of the length of leading jet. Then the decrease of the length of leading jet accompanied the decrease of residual penetration depth.

EO Characteristic in the Advanced Vertical Alignment (VA)- π Cell a Homeotropic Blended Polymer (수직 복합폴리머 표면을 이용한 Advanced VA-π cell의 전기 광학 특성)

  • 황정연;이경준;조용민;서대식
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.9
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    • pp.826-832
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    • 2003
  • Blending effects for generating a pretilt angle in nematic liquid crystal (NLC) with negative dielectric anisotropy on the blended polyimide (PI) of homeotropic and homogeneous alignment surface were studied. Also, we investigated the EO performances for the advanced VA- $\pi$ cell using this homeotropic blended PI surface. A many decrease of tilt angle on the polymer surface to blend homeotropic PI and homogeneous PI with side chain type was measured, and the tilt angle decreased as blended ratio and rubbing strength increase. However, a small decrease of tilt angle on the polymer surface to blend homeotropic PI and homogeneous PI with main chain type was measured. The blended effects for generating a pretilt angle were clearly observed, and the many decrease of tilt angle can be achieved by using the blended PI surface. The electro-optical (EO) characteristics using the advanced VA- $\pi$ cell using the homeotropic blended PI surface than that of conventional VA cell can be improved. We suggest that the developed advanced VA-$\pi$ cell on a homeotropic blended PI surface is a promising technique for the achievement of a fast response time, and a high contrast ratio.

Effect of Soil Strength on Seedling Emergence of Rice and Barnyardgrasses in Direct Dry-Seeding (건답직파에서 토양경도가 벼와 피의 출아에 미치는 영향)

  • Kwon, Yong-Woong;Lee, Byun-Woo;Kim, Do-Soon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.4
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    • pp.489-495
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    • 1996
  • Seedling emergences of four rice varieties (Dongjinbyeo, Dadajo, Galsaekggarak-sharebyeo, and Italiconaverneco) and three barnyardgrass species(Echjnochloa oryzjcola, E. crus-gali var. crus gali E. crus-gali var. praticola) were evaluated in relation to soil strength. Soil strength was varied by compressing the entire volume of soil with a hydraulic jack so as to be 0.5, 1, 2, 3, 6kg /$\textrm{cm}^2$. Soil strength was measured with a penetrometer (Yamanaka type) and soil covering above the seed was 4cm deep. Experiments were conducted at two air temperature conditions of 17 and $25^{\circ}C$. At a soil strength of up to 2kg/$\textrm{cm}^2$, little or no decrease in seedling emergence occurred in all rice varieties and barnyardgrasses tested. Above that value, seedling emergence decreased progressively as the soil strength increased. The degree of decrease was greatest in Dongjinbyeo and smallest in Dadajo among tested rice varieties, and greatest in Echinochloa oryzicola among barnyardgrasses, being greater in barnyardgrasses than rice. Seedling emergence was delayed almost linearly as the soil strength increased. The delay was greatest in Dongjinbyeo among rice varieties and in Echinochloa oryzicola among barnyardgrasses. Mesocotyl length increased as soil strength increased up to 2 to 3kg / $\textrm{cm}^2$ in Dongjinbyeo and Dadajo in 17$^{\circ}C$ and $25^{\circ}C$, and up to 6kg/$\textrm{cm}^2$ in Galsaekggaraksharebyeo and Italiconaverneco in $25^{\circ}C$. Dongjinbyeo showed the least elongation of mesocotyl among rice varieties in any soil strength. The total length of mesotyl, first internode and incomplete leaf showed little variation with soil strength. The total length was longer than the 4cm covering depth in other varieties except Dongjinbyeo. This might have caused the lower emergence rate in Dongjinbyeo than other varieties in higher soil strength.

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