• Title/Summary/Keyword: Polyethylene tube

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An Evaluation on the Properties of the Hardened Lightweight Cement Using the Polyethylene Tube (폴리에틸렌 튜브를 혼입한 경량 시멘트 경화체의 기초물성 평가)

  • Kim, Sae-Young;Jeon, Bong-Min;Kim, Hyo-Youl;Oh, Sang-Gyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.11a
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    • pp.57-60
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    • 2006
  • This study proposes the physical properties of the hardened lightweight cement using the polyethylene tube and to make the fundamental data regarding a new lightweight concrete development. The aerated concrete is displaying various effects such as lightweight, insulation characteristic and it is coming to be widely applied the slab layer of apartment as an insulating material but currently the aerated concrete has many problems. Therefore, demonstrating similar property of former aerated concrete and improving the defects, developing new hardened cement is needed. In this study, we predict adopting possibility of hollow core polyethylene tube, as a material to make cement hardening containing a lot of void. So we changed the mixing ratio, a diameter and length of the polyethylene tube and improved the compressive strength and unit capacity weight of the lightweight cement hardening body. From the test results, we judge that the aerated concrete is a developmental possibility.

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High-Temperature Drying of Bamboo Tubes Pretreated with Polyethylen Glycol Solution

  • Kang, Chun-Won;Chung, Woo-Yang;Han, Jae-Ok;Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.2
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    • pp.139-146
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    • 2017
  • This study was conducted to develop a new drying technology in order to quickly and massively dry bamboo tubes without crack and check. The bamboo tubes with the diameter of 45 mm - 68 mm had been impregnated in the solution of PEG-1000, and then were dried under room temperature and high temperature, respectively. The cracks occurred on all control specimens while no cracks were found on PEG treated specimens during drying at room temperature due to effect of PEG restraining the circumferential shrinkage of bamboo tube. But the drying period of this method was too long (200 days) compared to 10 hours of kiln drying. During fast high temperature drying, cracks occurred on all control specimens, but no cracks were found on PEG treated specimens, which could be accounted for more solidified PEG due to higher drying temperature and faster drying rate, and the tension set formed on the surface of bamboo tube in the early stage of drying owning to high drying temperature and low relative humidity. Thus, it is advised that PEG treated bamboo tube should be fast dried at high temperature in order to not only prevent crack or check in short drying period but also increase the dimensional stability of the products made of bamboo tubes.

Attraction of Plautia stali (Hemiptera: Pentatomidae) to Different Amounts of Its Aggregation Pheromone and the Effect of Different Dispensers (집합페로몬의 함량과 방출기 종류에 따른 갈색날개노린재(Plautia stali)의 유인)

  • Park, Gyeong-Mi;Jang, Sin-Ae;Choi, Seon-Hee;Park, Chung-Gyoo
    • Korean journal of applied entomology
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    • v.49 no.2
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    • pp.123-127
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    • 2010
  • Attractiveness of different amounts of methyl (E,E,Z)-2,4,6-decatrienoate, the aggregation pheromone of brown-winged stink bug, Plautia stali (Hemiptera: Pentatomidae), was tested using different kinds of dispensers. A lure filled with hexane was used as a control treatment. There were no differences in the attractiveness of the pheromone to P. stali and Halyomorpha halys among dispensers (polyethylene-vial, rubber septum, and polyethylene tube). Traps baited with 7, 20, 40, 50, and 60 mg of pheromone were tested for their attractiveness. For females, the 40 mg trap attracted highest number of P. stali, even though there were no significant differences among pheromone amounts. For males, the 40 and 50 mg traps attracted significantly more bugs than the 7, 20, and 60 mg traps and the control traps. Based on these results, the pheromone dispenser impregnated with 40 mg of pheromone will be practical in monitoring P. stali in the field.

Joining Condition of Engineering Plastic for Car (자동차용 엔지니어링 플라스틱의 접합조건)

  • Lee, Jung-Hyun;Lee, Woo-Ram
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.1
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    • pp.96-102
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    • 2012
  • The current establishment of car engineering plastic piping polyethylene (PE) tube used as bonding state or part of the health or safety of fusion is very important. A part of these fusion methods to determine the soundness of the short-term trials and long-term tests can be largely classified. Typical tests included short-term strength, tensile strength, impact strength, compressive strength, resiliency and compression. Polyethylene (PE) pipes installed in the domestic terms of overall penetration rate of 45% has been used. However, polyethylene (PE) pipes have reliability problems, and these occurs mostly in part by defective welding. Therefore, the test is necessary for safety. Non-destructive methods (ultrasonic testing) are difficult to be used. Therefore, Polyethylene (PE) pipe are used. Fusion of thses materilas is necessary in these field however, its technical, and basic research has not been studied well. In this research, short-term strength of welding parts, its tensile strength, hardness, fatigue, and microstructure have been analyzed to find the optimum process conditions to improve mechanical properties.

Steel and FRP double-tube confined RAC columns under compression: Comparative study and stress-strain model

  • Xiong, Ming-Xiang;Chen, Guangming;Long, Yue-Ling;Cui, Hairui;Liu, Yaoming
    • Steel and Composite Structures
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    • v.43 no.2
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    • pp.257-270
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    • 2022
  • Recycled aggregate concrete (RAC) is rarely used in load-carrying structural members. To widen its structural application, the compressive behavior of a promising type of composite column, steel-fiber reinforced polymer (FRP) double-tube confined RAC column, has been experimentally and analytically investigated in this study. The objectives are the different performance of such columns from their counterparts using natural aggregate concrete (NAC) and the different mechanisms of the double-tube and single-tube confined concrete. The single-tube confined concrete refers to that in concrete-filled steel tubular (CFST) columns and concrete-filled FRP tubular (CFFT) columns. The test results showed that the use of recycled coarse aggregates (RCA) affected the axial load-strain response in terms of deformation capacity but such effect could be eliminated with the increasing confinement. The composite effect can be triggered by the double confinement of the steel and carbon FRP (CFRP) tubes but not by the steel and polyethylene terephthalate (PET) FRP tubes. The proposed analysis-oriented stress-strain model is capable to capture the load-deformation history of such steel-FRP double-tube confined concrete columns under axial compression.

A Study of Welding Conditions for Plastic Piping (플라스틱 배관의 접합 조건에 관한 연구)

  • Lee, C.K.;Lee, W.R.;Park, C.Y.
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.5
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    • pp.564-569
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    • 2011
  • The current establishment of city gas piping polyethylene (PE) tube used as bonding state or part of the health or safety of fusion is very important. A part of these fusion methods to determine the soundness of the short-term trials and long-term tests can be largely classified. Typical tests include short-term strength, tensile strength, impact strength, compressive strength, resiliency and compression. Polyethylene (PE) pipes installed in the domestic terms of overall penetration rate of 45% has been used. However, polyethylene (PE) pipes have reliability problems, and these occurs mostly in part by defective welding. Therefore, the test is necessary for safety. Non-destructive methods (ultrasonic testing) are difficult to be used. Therefore, Polypropylene copolymer (PP-C), polypropylene homopolymer (PP-H), and polyethylene (PE) pipe are used. Fusion of these materials is necessary in these field however, its technical, and basic research has not been studied well. In this research, short-term strength of welding parts, its tensile strength, hardness, fatigue, and microstructure have been analyzed to find the optimum process conditions to improve mechanical properties.

A Study on the Explosive Plugging of A Repair for Defective Tube/Tubeplate on the Nuclear Steam Generator (원자력 증기발생기 결함 세관 보수용 폭발 Plugging에 관한 연구)

  • 이병일;심상한;강정윤;이상래
    • Explosives and Blasting
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    • v.17 no.4
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    • pp.18-31
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    • 1999
  • The explosive forming has been used for many year to expand tubes into tubesheets. this process has demonstrated ability to direct carefully the energy of an explosive to expand tubes into tubesheet holes without damaging the tubesheet and without causing the excessive cold work at the tube I.D. that is normally associated with mechanical expansion. The success of explosive tube expansion provided the background for the development of the explosive tube plug. The main results are as follows : (1) The optimum explosives and explosive qualities are PETN, RDX, HMS and about 18~31gr/ft of explosive plugging in nuclear steam generator. (2) Explosive plugging's thickness is 0.9~1.8mm. If groove of 0.4 mm formed in plug outside, For the hydraulic leakage is go up, explosive plugging of formed groove are applicate tube and tubrplate. (3) Sheath is designed on the polyethylene of low density, In thermal impact test of the $430^\circ{C}$, hydraulic leakage is $300kg/cm^2$. (4) About 10~60mm oxide inclusions are existed on the space of explosive plug and tube protect to the leakage.

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A Study on Heat Transfer Performance of Vertical Ground Heat Exchanger of GSHP(Ground Source Heat Pump) (GSHP용 수직형 지중열교환기의 열전달 성능에 관한 연구)

  • Chung, Min-Ho;Chang, Ki-Chang;Ra, Ho-Sang;Baik, Young-Jin;Park, Seong-Ryong;Yoo, Seong-Yeon
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2102-2107
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    • 2007
  • GSHP systems are used for air-conditioning systems in commercial buildings, schools, and factories because of low operating and maintenance costs. These systems use the earth as a heat source in heating and a heat sink in cooling mode. Ground heat exchangers are classified by a horizontal and vertical type according to the installation method. Vertical type is usually constructed by placing small diameter high density polyethylene tube in a vertical borehole. Vertical tube sizes range from 20 to 40 mm nominal diameter. Borehole depth range between 100 and 200 m depending on local drilling conditions and available equipment. In this study, to evaluate the performance of single u-tube with bentonite grouting, single u-tube with broken stone grouting and double u-tube bentonite grouting of vertical ground heat exchangers, test sections are buried on the earth and experimental apparatus is installed. Therefore the heat transfer performance and pressure loss of these are estimated.

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A Study on Performance of Vertical Ground Heat Exchanger for Heat Pump (히트펌프용 수직형 지중열교환기의 성능에 관한 연구)

  • Chang, Ki-Chang;Chung, Min-Ho;Yoon, Hyung-Kee;Ra, Ho-Sang;Yoo, Seong-Yeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.466-469
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    • 2007
  • Heat pumps are used for air-conditioning systems in commercial buildings, schools, and factories because of low operating and maintenance costs. These systems use the earth as a heat source in heating mode and a heat sink in cooling mode. Ground heat exchangers are classified by a horizontal type and vertical type according to the installation method. A horizontal type means that a heat exchanger is laid in the trench bored in 1.2 to 1.8 m depth. And a vertical type is usually constructed by placing small diameter high density polyethylene tube in a vertical borehole. Vertical tube sizes range from 20 to 40 mm nominal diameter. Borehole depth range between 100 and 200 m depending on local drilling conditions and available equipment. In this study, to evaluate the performance of single u-tube with bentonite grouting, single u-tube with broken stone grouting and double n-tube bentonite grouting of vertical ground heat exchangers, test sections are buried on the earth and experimental apparatus is installed. Therefore the heat transfer performance and pressure loss of these are estimated.

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The Effect of the Molecular Weight of Poly(ethylene glycol) on Diffusion through Cellulose (폴리에틸렌글리콜의 분자량에 따른 셀룰로스에서의 확산 거동)

  • 윤기종;우종형;서영삼
    • Textile Coloration and Finishing
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    • v.16 no.1
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    • pp.48-52
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    • 2004
  • Diffusion/penetration rates of finishing agents are not a major criterion in the design of low molecular weight finishing agents. However, in the case of polymeric finishing agents, high molecular weights result in large hydrodynamic volumes and diffusion/penetration of the finishing agent into the substrate may become a critical factor in the design of textile finishing agents. Thus the effect of the molecular weight of a model compound, polyethylene glycol, on its diffusion through a cellulose membrane or cotton fabric is studied. Diffusion experiments of polyethylene glycol of molecular weight 400, 1000, 2000, 4600, 8000, and 10000 through cellulose membrane or fabric was carried out in a glass U-tube diffusion apparatus and the half penetration times and the penetration coefficients were determined. Both the half penetration times and the penetration coefficients exhibited a significant change between molecular weight 2000 and 2500 as the molecular weight of polyethylene glycol increased, suggesting that there is a critical molecular weight above which diffusion/penetration becomes difficult. Based on this study on a model compound, it is suggested that polymeric textile finishing agents can be expected to exhibit similar behavior.