International Journal of Materials Science and Applications

Volume 7, Issue 3, May 2018

  • A Research on Colours and Fastness Values of Different Materials Dyed with Some Natural Dyes

    Selma Dolanbay Doğan, Meral Akan

    Issue: Volume 7, Issue 3, May 2018
    Pages: 69-74
    Received: 12 February 2018
    Accepted: 13 March 2018
    Published: 4 April 2018
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    Abstract: Nowadays use of natural materials and natural methods is considered to be an element that increases the value of a product and contributes to sustainable life in environmental, economic and sociologic senses. Natural dyeing has been an avocation performed in the Anatolia region for centuries and can be used for dyeing of different materials. In thi... Show More
  • Analysis of the Interaction of NH4Cl-Doped Process Gases with Zinc-Coated Surfaces with Regard to Aluminum Brazing with Zn-AlSi Duplex Braze Metal Coatings

    André Langohr, Sarah Groß-Bölting, Ulrich Holländer, Kai Möhwald

    Issue: Volume 7, Issue 3, May 2018
    Pages: 75-84
    Received: 14 December 2017
    Accepted: 26 January 2018
    Published: 23 April 2018
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    Abstract: This paper reports on the development of a braze metal coating and a brazing process for joining aluminum alloys at temperatures < 570°C without applying a flux before brazing. This is achieved using a duplex braze metal coating made of an aluminum-silicon alloy and zinc as top layer in combination with the use of hydrogen chloride doped nitrogen as process gas. Here hydrogen chloride deoxidate the surface of the zinc coating and form zinc chloride flux in-situ. Defined hydrogen chloride partial pressures between 100 vpm (volume parts per million) and 300 vpm in nitrogen were produced by thermal decomposition of solid ammonium chloride. Reaction kinetics of hydrogen chloride with the zinc coating was investigated by detecting the generation of reaction heat at different hydrogen chloride concentrations and temperatures. An activation energy of was determined, a value that matches the values stated in the literature. The order of reaction n was found to be significantly lower than 1, which is consistent with gas solid reactions at microscopically fissured interfaces. An in-situ zinc chloride formation rate of 3 µg/(min cm2) at 400°C and 200 vpm hydrogen chloride concentration was obtained from the measured data, which may be sufficient for triggering the flow of braze metal. Experimental brazing tests showed, that when the reaction time was long enough to permit the formation of zinc chloride and this is followed than by a brazing process at 560°C to 570°C in subsequently hydrogen chloride-free nitrogen atmosphere, a liquid ternary AlSiZn braze metal is formed from the dublex coating enabling a wetting and brazing of the contacting join partner.
  • The Effects of Ozone Bleaching and Ozone Desizing Method on Whiteness and Water Absorption of 100% Cotton Terry Fabrics

    Yıldıray Turhan, Şeyma Soydaş

    Issue: Volume 7, Issue 3, May 2018
    Pages: 85-94
    Received: 11 March 2018
    Accepted: 27 March 2018
    Published: 24 April 2018
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    Abstract: In this study, the effects of ozone desizing and bleaching on the hydrophilicity and whiteness of terry fabrics were investigated. The results were compared with those obtained after conventional desizing and bleaching (hydrogen peroxide bleaching). The test samples contain two side piled woven terry cloths of four different areal weights. The ozon... Show More
  • Selective Separation of Organic Electrolytes by Neutralization Dialysis with Grafted Polyethylene Films

    Yuji Kimura, Kazunori Yamada

    Issue: Volume 7, Issue 3, May 2018
    Pages: 95-105
    Received: 14 November 2017
    Accepted: 30 November 2017
    Published: 26 April 2018
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    Abstract: The selective separation of organic electrolytes by neutralization dialysis was investigated with two kinds of grafted polyethylene (PE) films prepared through the photografting of 2-(dimethylamino) ethyl methacrylate (DMAEMA) onto the PE films and the subsequent quaternization and through the photografting of glycidyl methacrylate (GMA) and the su... Show More
  • Evaluation of Sample-Electrode Contact Impedance in Two-Point Measured AC Impedance Spectroscopy of Cement-Based Materials

    Fuqiang He, Ruipan Wang, Runxiao Zhang, Changping Chen, Li Lin, Xiaopeng An

    Issue: Volume 7, Issue 3, May 2018
    Pages: 106-114
    Received: 11 March 2018
    Accepted: 24 April 2018
    Published: 22 May 2018
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    Abstract: In this study, AC impedance spectroscopy measurements of cement paste with 0.5 W/C were collected and interpreted using different electrode-sample contact methods. The results indicated that when using a conductive glue contact (CG), two capacitive loops and an inclined line appeared within the frequency range of 100-0.1 Hz. An equivalent circuit, ... Show More