• Title, Summary, Keyword: Fusion temperature

Search Result 592, Processing Time 0.048 seconds

The Fusion Characteristic Varying with Butt Fusion Times for Polyethylene Pipe (PE배관 버트 융착 시간에 따른 융착 특성 변화)

  • 이영순;장영오
    • Journal of the Korean Society of Safety
    • /
    • v.13 no.4
    • /
    • pp.199-205
    • /
    • 1998
  • Butt fusions were practiced with butt fusion in the various conditions of fusion temperatures, pressure and time, and the tests of tesile strength, breaking water pressure and fusion features were also practiced so that the reliability of the butt fusion and the fittets fusion condition may be closely examined. And the width, height and thickness of the beads were also closely measured. The fittest fusion result was achieved in the condition of the temperature of $210^{\circ}C$, heating time hight pressure of 14 seconds on the pressure of $1.5kg/cm^2$, heating time hight pressure of 100 seconds and pressure buid-up time of 11 seconds. And in case of the temperature of $250^{\circ}C$, the fittest fusion result was showed in the condition of the heating time hight pressure of 3 seconds on the pressure of 1.0$kg/cm^2$, the heating time low pressure variable of 100 seconds. heating time hight pressure of 14 seconds and the heating maintenance of around 60 seconds. The result of breaking water pressure test of a test piece fusion in the fittest fusion condition was that the fusion condition of the PE pipe showed a good stability and hight reliance. Through this test, it is proved that the temperature of fusion PE pipes can be increased to $250^{\circ}C$ from $210^{\circ}C$. And it can be expected that the above fusion method greatly helps to reduce the fusion time.

  • PDF

Temperature Dependence of the Electro-optic Characteristics in the Liquid Crystal Display Switching Modes

  • Jeon, Eun-Jeong;Srivastava, Anoop Kumar;Kim, Mi-Young;Jeong, Kwang-Un;Choi, Jeong-Min;Lee, Gi-Dong;Lee, Seung-Hee
    • Journal of Information Display
    • /
    • v.10 no.4
    • /
    • pp.175-179
    • /
    • 2009
  • As the physical properties of nematic liquid crystals vary with respect to temperature, the performances of liquid crystal displays (LCDs) are highly dependent on temperature. Additionally, it is well known that the electro-optic characteristics of LCDs, such as transmittance and threshold voltage, also rely on the LCD switching modes. The temperature dependence of the electro-optic characteristics of the wide-viewing-angle LCD modes, such as in-plane switching (IPS), multidomain vertical alignment by patterned electrode (PVA), and fringe-field switching (FFS), have been studied, and the results showed that the FFS mode has lower temperature dependence compared to the IPS and PVA modes. Since the liquid crystal (LC) reorients in different ways in each mode, this result is associated with the temperature dependence of LC's bend and twist elastic constants, and also with the position of the main reorientation, either in the middle or on the surface of the LC layer.

Synthesis and Temperature-Dependent Local Structural Properties of Ti2O3

  • Hwang, Inhui;Jin, Zhenlan;Park, Changin;Jiang, Bingzhi;Han, S.W.
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • /
    • pp.202.2-202.2
    • /
    • 2013
  • Ti2O3 is known as a typical Mott insulator with a transition temperature of near $200^{\circ}C$. Unlike VO2, Ti2O3 does not have a structural phase transition near the metal-insulator-transition (MIT) temperature. We investigated the temperature-dependent thermal vibration change using temperature-dependent x-ray absorption fine structure (XAFS) at Ti K-edge in the temperature range of 300~600 K. Ti2O3 powder and films were synthesized using thermal chemical vapor deposition (CVD) at $800{\sim}900^{\circ}C$. X-ray diffraction measurements show a single phased Ti2O3 at room temperature. XAFS confirmed no structural phase transition in the temperature of 300~600 K. A small but distinguishable structural disorder change was observed near the transition temperature. We will discuss the MIT behavior with the change of structural disorder.

  • PDF

Temperature dependent electro-optical studies of liquid crystal in Fringe Field Switching (FFS), In-plane switching (IPS), and Patterned Vertical Alignment (PVA) modes

  • Jo, Eun-Mi;Srivastava, Anoop Kumar;Kim, Mi-Young;Kim, Sung-Min;Lee, Seung-Hee;Ji, Seung-Hoon;Lee, Gi-Dong
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • /
    • pp.320-323
    • /
    • 2008
  • In this paper, electro-optical characteristic of Nematic Liquid crystal (LC) with varying temperature in different LCD modes, namely Fringe Field Switching (FFS), In-plane switching (IPS), and Patterned Vertical Alignment (PVA) modes are investigated and compared. Electro optic me asurements suggest that rate of change of transmission with temperature in FFS mode was lowest and much more thermally stable as compared to IPS and PVA m odes. However the electro-optical characteristic of patterned vertical alignment (PVA) mode was most affected by changing temperature. The measured threshold voltage was found to be much more thermally stable in FFS and IPS modes than that of PVA mode.

  • PDF

Hyper Neutral Beam System for Damage Free Deposition of Indium-Tin Oxide Thin Films at Room Temperature

  • Yoo, Suk-Jae;Kim, Dae-Chul;Kim, Jong-Sik;Oh, Kyoung-Suk;Lee, Bong-Ju;Choi, Soung-Woong;Park, Young-Chun;Jang, Jin-Nyoung;Hong, Mun-Pyo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • /
    • pp.190-192
    • /
    • 2007
  • A neutral beam system has been developed to produce hyperthermal neutral beams composed of indium, tin, and oxygen atoms. Using these hyper thermal neutral beams with energies in the range of tens of eV, high quality indium-tin oxide (ITO) thin films have been obtained on glass substrates at room temperature. The optical transmittance of the films is higher than 85% at a wavelength of 550 nm and the electrical resistivity is lower than $1{\times}10^{-3}{\Omega}cm$.

  • PDF

Development of High Performance Indium Tin Oxide Films at Room Temperature by Plasma-Damage Free Neutral Beam Sputtering System

  • Jang, Jin-Nyoung;Oh, Kyoung-Suk;Yoo, Suk-Jae;Kim, Dae-Chul;Lee, Bon-Ju;Yang, Ie-Hong;Moon, Ji-Sun;Kim, Jong-Sik;Choi, Soung-Woong;Park, Young-Chun;Hong, Mun-Pyo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • /
    • pp.1715-1718
    • /
    • 2007
  • New ITO thin film of good performance has been developed by brand-new, plasma-damage-free sputtering process at the room temperature. The room temperature-processed ITO films with optimized conditions as neutral beam acceleration bias of -30V and In & Sn composition ratio of 99:01 gives lower resistivity as $4.22{\times}10^{-4}{\Omega}-cm$ and higher transmittance over 90% a wavelength of 550 nm. The transmission electron microscope (TEM) images of the films show a nano-crystalline structure.

  • PDF

Effects of Final Heat Treatment on Corrosion and Mechanical Properties of Zr Alloy Strip Incorporating Nb (니오븀이 첨가된 Zr 합금 스트립의 부식 및 기계적 특성에 대한 최종열처리 영향)

  • Lee, Myung Ho;Jung, Yang Il;Choi, Byoung Kwon;Park, Sang Yoon;Kim, Hyun Gil;Park, Jeong Yong;Jeong, Yong Hwan
    • Korean Journal of Metals and Materials
    • /
    • v.47 no.8
    • /
    • pp.474-481
    • /
    • 2009
  • The effects of final heat treatment on the mechanical and corrosion properties of a Zr alloy strip incorporating Nb were investigated. The chemical composition of the strip was Zr-1.49Nb-0.38Sn-0.20Fe-0.11Cr, and strip specimens were subjected to final heat treatment in a temperature range of $580{\sim}700^{\circ}C$. Tensile tests at room temperature and $316^{\circ}C$, along with corrosion tests in a simulated PWR loop and a 70 ppm LiOH solution environment at $360^{\circ}C$, were performed on the specimens. The mechanical properties of the strip were saturated when the specimens received final heat treatment at an elevated temperature of more than $640^{\circ}C$. However, the corrosion resistance of the strip in the simulated PWR loop and in the 70 ppm LiOH solution environment was improved with a decrease of the final annealing temperature. It is recommended that the alloy strip be finally heat-treated at a temperature of less than $620^{\circ}C$ for longer than 10 minutes in order to obtain fully recrystallized microstructures, and thereby attain enlarged tensile elongation, and to prevent the precipitation of ${\beta}-Zr$, which is known to deteriorate the corrosion resistance.

Temperature-dependent Structural and Magnetic Properties of Diamagnetic $HgI_2$

  • Park, C.I.;Jin, Zhenlan;Hwang, I.H.;Yeo, S.M.;Han, S.W.
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • /
    • pp.291.1-291.1
    • /
    • 2013
  • We examined the temperature-dependent structural and magnetic properties of HgI2 in the temperature range of 300~400 K. HgI2 is a diamagnetic material and can be used for X-ray or γ-ray detectors. DCmagnetization measurements on HgI2 showed that there is a small but distinguishable change in its diamagnetic properties near 375 K. The magnetic property change is not expected because Hg and I are known as nonmagnetic elements. X-ray diffraction (XRD) measurements revealed a structural transition in the temperature of 350~400 K. Temperature-dependent x-ray absorption fine structure (XAFS) demonstrated that the chemical valence states of both Hg and I did not changed in the temperature range of 300~400 K. However, XAFS revealed that the bond-length disorder was slightly increased in the temperature range, particularly, near Hg atoms. The structural changes of HgI2 are likely related to its diamagnetic property change. We will discuss the relation between the diamagnetic properties and local structural properties of HgI2 in detail.

  • PDF

Preparation of Poly(p-dioxanone) Non-covens by Electrospinning and Their In -vitro Degradation Behavior (Electrospinning을 이용한 Poly(p-dioxanone) 부직포 제초 및 In -vitro 분해거동)

  • 김학용;이세철;이근형;이덕래;박수진
    • Textile Science and Engineering
    • /
    • v.39 no.3
    • /
    • pp.306-315
    • /
    • 2002
  • The poly(p-dioxanone)(PDO) non-wovens whose fiber diameters were below 10$\mu$m were prepared by melt electrospinning. The morphology and fiber diameter of PDO non-wovens were studied under different eletrospinning conditions such as temperature and applied voltage. The fiber diameter decreased with increasing temperature and applied voltage. Proper fiber bond structure was formed in the PDO non-woven fabrics at 12kV. 19$0^{\circ}C$ respectively. In most of the samples, heat of fusion of the electrospun non-wovens was less than the raw PDO. In order to increase th crystallinity of electrospun PDO non-wovens, annealing was carried out at 50~9$0^{\circ}C$, for 15hrs under nitrogen atmosphere. The heat of fusion of PDO non-wovens increased with increasing the annealing temperature. The PDO non-wovens annealed at different temperatures were degraded at different rates in saline buffer solution at 37$^{\circ}C$. The degradation characteristic of PDO non-wovens was analyzed with heat of fusion, viscosity, PH, and weight loss. Relatively, higher heat of fusion resulted from annealing in the temperature range of 60~8$0^{\circ}C$ as compared with the raw PDO. The heat of fusion increased with increasing immersion time at all annealing temperatures.

Novel deposition technology for nano-crystalline silicon thin film at low temperature by hyper-thermal neutral beam assisted CVD system

  • Jang, Jin-Nyoung;Song, Byoung-Chul;Oh, Kyoung-Suk;Yoo, Suk-Jae;Lee, Bon-Ju;Choi, Soung-Woong;Park, Young-Chun;Hong, Mun-Pyo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • /
    • pp.1025-1027
    • /
    • 2009
  • Novel low temperature deposition process for nano-crystalline Si thin film is developed with the hyper-thermal neutral beam (HNB) technology. By our HNB assisted CVD system, the reactive particles can induce crystalline phase in Si thin films and effectively combine with heating effect on substrate. At low deposition temperature under $80^{\circ}C$, the HNB with proper incident energy controlled by the reflector bias can effectively enhance the nano-crystalline formation in Si thin film without any additional process. The electrical properties of Si thin films can be varied from a-Si to nc-Si according to change of HNB energy and substrate temperature. Characterization of these thin films with conductivity reveal that crystalline of Si thin film can increase by assist of HNB with appropriate energy during low temperature deposition. And low temperature prcoessed nc-Si TFT performance has on-off ratio as order 5.

  • PDF