• Title/Summary/Keyword: Surface protector

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An Analysis on the Changes of Knees and Hip Joint Surface according to Elderly Women's Movements (노년 여성의 동작에 따른 무릎 및 고관절 주변 체표 길이 변화 분석)

  • Jang, Ji Hyeon;Jung, Hee Kyeong;Park, Jung Hyun;Lee, Jeong Ran
    • Fashion & Textile Research Journal
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    • v.22 no.2
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    • pp.222-232
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    • 2020
  • This study analyzes changes in the knees, hips, and hip joint length according to the different angles of bending knees by 45°, 90°, and 135° respectively for knees, hips, and the hip joint that have high fracture rates when falling down. The research subjects were 10 elderly women in their 60s (or older) that obtain data collected through direct measurement. For analysis, the study drew a diagram of elongation and shrinkage based on changes and change rate from a straight posture (0°) and conducted a statistical analysis on differences of body surface length by zone according to movements. The more the knees were bent, the vertical surface length in front of the knees, the horizontal surface length above the knee line, the horizontal body surface length below the knee lines on the back, and the vertical surface lengths between front side lines and the side lines increased; however, the vertical surface length on the back decreased. For the hip joint, the difference in the vertical surface length was more distinctive when compared to the horizontal. Finally, the horizontal surface length increased below the hips and the vertical surface length increased in most areas except the sidelines and the front. The result of the change in body surface length according to the movements of this study can be utilized in the development of the motion-variable protector.

Reinforcement of Shotcrete Lining on the Side Wall of Tunnel in Enlargement of Existing ASSM Road Tunnel (측벽부 숏크리트 보강에 의한 재래식 도로터널 단면확대)

  • Kim, Donggyou;Shin, Youngwan
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.12
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    • pp.81-89
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    • 2012
  • The existing tunnel in urban area can be enlarged because of requirement of road-widening by traffic growth. The protector with rectangular cross section can be set up in the tunnel, which will be constructed for enlargement of width, to solve traffic jam around the tunnel. It is impossible to install the rockbolt in the lower area of tunnel due to a limited space between the protector and cutting surface. The objective of this study is to suggest the method of shotcrete thickness increase instead of rockbolt installation in the side wall of tunnel for the stability of tunnel. Numerical analysis was performed to evaluate displacement at the crown of tunnel, convergence of tunnel, and stress in shotcrete lining in 3-lane and 4-lane NATM tunnels enlarged from 2-lane conventional tunnel. There were three types of analysis condition, rockbolt installation, no rockbolt installation, and increase of shotcrete thickness without rockbolt in the side wall of tunnel. There was no difference on the displacement at the crown and the convergence of upper tunnel. In the lower tunnel, the convergence in case of no rockbolt installation was larger as maximum 1.3mm than that in case of rockbolt installation. The stress in shotcrete lining in case of no rockbolt installation was larger as maximum 1.3MPa than that in case of rockbolt installation. Numerical analysis was performed to compare the behavior of shotcrete with rockbolt with that of shotcrete, which its thickness was increased, without rockbolt. The shotcrete has an increase of 20%(250mm ${\rightarrow}$ 300mm, 4-lane tunnel)~25%(200mm ${\rightarrow}$ 250mm, 3-lane tunnel) in its thickness to reduce the stress in shotcrete lining. The behavior of shotcrete lining increased the shotcrete thickness by 20%~25% was similar to that of existing shotcrete lining with rockbolt.

Section enlargement by reinforcement of shotcrete lining on the side wall of operating road tunnel (운영중인 도로터널의 측벽하부 숏크리트 보강에 의한 단면확대)

  • Kim, Dong-Gyou;Shin, Young-Wan;Shin, Young-Suk
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.6
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    • pp.637-652
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    • 2012
  • The protector with the shape of '${\sqcap}$' in cross section can be set up in the tunnel, which can be constructed for enlargement of cross section, to keep traffic flow in the tunnel. It is impossible to install the rockbolt in the side wall of tunnel due to a limited space between the protector and cutting surface of side wall. The objective of this study is to suggest the optimum thickness of shotcrete lining without rockbolt on the side wall and to evaluate the stability of tunnel enlarged. Numerical analysis was performed to evaluate the displacement at the center of tunnel, the convergence of tunnel, and the stress in shotcrete lining in 4-lane NATM road tunnel enlarged from 3-lane NATM road tunnel. The vertical displacement at the center of tunnel and the convergence of crown in the tunnel with rockbolt in the side wall were almost similar to those in the tunnel without rockbolt in the side wall. The convergence of bench/invert and the stress in shotcrete lining without rockbolt on the side wall were greater maximum 0.57 mm and 1,300 kN/$m^2$ than those with rockbolt in the side wall. The increased convergence and the stress in shotcrete lining can be reduced in incerasing of thickness of shotcrete lining about 20% (5 cm) of standard thickness, 25 cm, of shotcrete lining.

Study on the gate cutting of light guiding plate for mobile using quenching element (박형 도광판의 음각, 양각 마이크로 패턴 성형성에 관한 연구)

  • Hwang, Chul-Jin;Kim, Jong-Sun;Min, In-Gi;Kim, Jong-Dug;Yoon, Kyung-Hwan
    • Design & Manufacturing
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    • v.2 no.5
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    • pp.1-4
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    • 2008
  • LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LCP (Light Guide Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50-200{\mu}m$ in diameter on it by erosion method. But the surface of the erosion dots of LGP is very rough due to the characteristics of the erosion process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. Especially, the negative and positive micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP.

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Effect of Experimental Fluoride Varnish upon the Vickers Hardness of Bovine Teeth (실험용 불소바니쉬가 우치의 비커스 경도에 미치는 영향)

  • Kim, Ah-Jin;Son, Ju-Lee;Oh, Seunghan;Bae, Ji-Myung
    • Korean Journal of Dental Materials
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    • v.43 no.1
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    • pp.81-89
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    • 2016
  • The purpose of this study was to evaluate the effect of the experimental and commercial fluoride varnishes on the Vickers hardness of bovine teeth. The experimental fluoride varnishes with 5 wt.% NaF were fabricated using Bis-GMA or rosin as the resin base. The components were mixed with over-head stirrer under warming up in a double boiler for 30 minutes. Four commercial fluoride varnishes (V-varnish, Flor-opal, Cavity shield, Fluor protector) were compared with the experimental fluoride varnishes. Vickers hardness was measured on the labial surface of bovine anterior teeth after applying fluoride varnish on 5th and 30th day. The surface of bovine teeth was observed with a scanning electron microscope before and after applying fluoride varnish and the change of the components on the bovine teeth surface was measured with EDX. In terms of hardness, the experimental rosin-based fluoride varnish showed significantly higher hardness on the 5th and 30th day than the control (bovine teeth without fluoride treatment)(p<0.05). EDX results showed that the fluoride content on the surface of bovine teeth treated with the experimental rosin-based fluoride varnish was highest on the 1st and 10th day. The higher hardness and fluoride content of experimental rosin-based fluoride varnish can be considered to be used as an effective fluoride varnish to prevent dental caries.

A Study on the Safety Assessment and Damage Pattern of Water Purifier Compressors (정수기용 압축기의 안전성 평가 및 소손 패턴 분석에 관한 연구)

  • Choi, Chung-Seog
    • Journal of the Korean Society of Safety
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    • v.28 no.2
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    • pp.21-25
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    • 2013
  • The purpose of this study is to provide basic data for the safety assessment of a water purifier when water leaks due to inappropriate maintenance and the examination of the cause of accidents related to the leak. Due to its inspection and management by non-specialists, if a leak occurs in a water purifier with the water level controller being inclined, it may result in the failure of the compressor, power supply line, PCB, etc. The analysis of the thermal diffusion pattern of water purifier compressors using a thermal image camera shows that its maximum temperature was approximately $80^{\circ}C$. In addition, its operating current was a maximum of 13 A and the system's operating current was approximately 1.7 A after the compressor was charged. It was found that the housing type power cable cover of the compressor had the effect of preventing electric shock but has poor flame resistance. Furthermore, the performance of the overload protector, PTC relays, etc., was excellent but they have potential for problems as metallic terminals were exposed, resulting in the potential of a safety related accident. The terminals and their surface damaged by the tracking showed a trace of carbonization and the resistance between terminals was measured to be approximately $8{\Omega}$. In addition, while the tracking was proceeding, the fuse and circuit breaker installed for system protection did not operate.

Optimization of Decolorizing and Carding Condition for Recycle Materials of Colored Waste Silk Fabrics (폐견직물의 재활용을 위한 탈색과 개섬조건의 최적화)

  • Lee, Youn-Eung;Lee, Sun-Kun;Joo, Chsang-Whan
    • Textile Coloration and Finishing
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    • v.17 no.6 s.85
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    • pp.42-50
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    • 2005
  • Silk fabrics are widely used as high quality cloth, interior, quilting and bedding materials because of having excellent touch, drape, resilience and low specific gravity characteristics. But, many waste silk materials are produced during the reeling, spinning, weaving, dyeing and finishing processes. From this fact, the recycle of waste silks is interested in studying for the application of industrial textile materials such as filter, oil absorbent and wound protector. Thus, this research has surveyed the decolorizing and carding characteristics in order to recycle the colored waste silk materials. As the results, the carding condition of waste silk fabrics was optimized with different fiber lengths and curding passage. In addition, the fiber failure mechanism from the wasted silk microdamage caused by carding process was investigated. Also it was found that longitudinal and transverse cracks, abrasion and pilling were formed on the surface of wasted silk fibers.

Reading Against the Grain: Whiteness, Class, and Space in William Faulkner's As I Lay Dying

  • Sa, Mi Ok
    • Journal of English Language & Literature
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    • v.64 no.2
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    • pp.239-252
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    • 2018
  • Many critics on William Faulkner's As I Lay Dying have read Addie Bundren as the disrupter of patriarchal power. By raising a question about the usefulness of language, which is the symbolic power of patriarchy and having an affair with the preacher Whitfield outside her wedlock, Addie directly challenges patriarchal power. From a quite different vantage point, however, we can read Addie as the faithful protector of the norm of whiteness in the South in light of the social hierarchy. As a former school teacher, Addie is from middle class before her marriage. By her marriage to Anse, who is a lower-class white, Addie has class anxiety that her social status in the stratum of whiteness could be degraded from a middle to a lower-class white, "white trash," which means that she is not white enough to be considered as the normative whiteness. Especially, Addie's anxiety increases due to the fact that her lazy husband is reluctant to work and relies on her neighbors, causing her family to be entrapped at the bottom in the stratum of whiteness. Therefore, she decides to take revenge on her husband after giving birth to her second child Darl by asking Anse to bury her dead body in her familial burial site in Jefferson. By rendering her family to suffer the hardship during her funeral procession, not only does she succeed in taking revenge on Anse on the surface, she regains her social status as a middle-class white by being buried in Jefferson fundamentally.

Coating Performance of SiO2 / Epoxy Composites as a Corrosion Protector

  • Rzaij, Dina R.;Ahmed, Nagham Y.;Alhaboubi, Naseer
    • Corrosion Science and Technology
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    • v.21 no.2
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    • pp.111-120
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    • 2022
  • To solve the corrosion problem of industrial equipment and other constructions containing metals, corrosion protection can be performed by using coating which provides a barrier between the metal and its environment. Coatings play a significant role in protecting irons and steels in harsh marine and acid environments. This study was conducted to identify an anti-corrosive epoxy coating for carbon steel composite with 0.1, 0.3, and 0.5 wt% concentrations of nanoparticles of SiO2 using the dip-coating method. The electrochemical behavior was analyzed with open circuit potential (OCP) technics and polarization curves (Tafle) in 3.5 wt% NaCl and 5 vol% H2SO4 media. The structure, composition, and morphology were characterized using different analytical techniques such as X-ray Diffraction (XRD), Fourier Transform Infrared spectrum (FT-IR), and Scanning Electron Microscopy (SEM). Results revealed that epoxynano SiO2 coating demonstrated a lower corrosion rate of 2.51 × 10-4 mm/year and the efficiency of corrosion protection was as high as 99.77%. The electrochemical measurement showed that the nano-SiO2 / epoxy coating enhanced the anti-corrosive performance in both NaCl and H2SO4 media.

A Study on the Effect of Optical Characteristics in 2 inch LCD-BLU by Aspect Ratio of Optical Pattern : I. Optical Analysis and Design (휴대폰용 2인치 LCD-BLU의 광특성에 미치는 광학패턴 세장비의 영향 연구 : I. 광학 해석 및 설계)

  • Hwang, C.J.;Ko, Y.B.;Kim, J.S.;Yoon, K.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.239-242
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    • 2006
  • LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LGP (Light Guiding Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50{\sim}200$ um in diameter on it by etching process. But the surface of the etched dots of LGP is very rough due to the characteristics of the etching process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current etched dot patterned LGP, optical pattern design with 50um micro-lens was applied in the present study. The micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different aspect ratio (i.e. $0.2{\sim}0.5$) of optical pattern conditions to the brightness distribution of BLU with micro-lens patterned LGP. Finally, high aspect ratio micro-lens patterned LGP showed superior results to the one made by low aspect ratio in average luminance.

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