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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 37 (1986), S. 110-110 
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 29 (1978), S. 265-267 
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Investigation into the effects of alternating current on magnesium anodesLaboratory tests were made to study the effects of alternating current on magnesium anodes. The electrolytes used were 20% soil solution (resistivity 34 Ωm), 0.72% sodium sulphate solution (resistivity 1 Ωm) and desalinated water (4.000 Ωm).The tests showed that it is not the a. c. voltage but the a. c. density which is the reason for a positive potential shift in magnesium anode systems. The critical density is 20 A/m2. Polarity reversal in the magnesium/iron galvanic cell occurs at an a. c. density of 60 A/m2 depending on the electrolyte; at this density, the anodic magnesium becomes cathodic. Magnesium anode mass loss tests carried out to study the effect of alternating current on magnesium anodes showed that the anode mass loss amounts to approx. 20 grammes/day/m2 at a current density of 20 A/m2; mass loss increases as a linear function of a. c. density.As far as pipeline applications are concerned, it is important to note that anode mass loss is particularly high in low resistivity soils in areas where high a. c. voltages are induced into the pipeline system.
    Notes: Es wurde der Wechselstromeinfluß auf Magnesiumanoden in Laborversuchen untersucht. Als Elektrolytlösung dienten 20%ige Bodenlösungen mit einem spezifischen Widerstand von 34 Ωm, 0,72%ige Natriumsulfatlösung 1 Ωm und entsalztes Wasser 4000 Ωm.Es zeigte sich, daß die maßgebende Größe, die eine Potentialverschiebung in positiver Richtung bei Magnesium hervorruft, nicht die Wechselspannung, sondern die Wechselstromdichte ist. Die Potentialänderung beginnt bei Wechselstromdichten ab 20 A/m2. Im galvanischen Element Magnesium/Eisen findet je nach Elektrolyt bei einer Wechselstromdichte um 60 A/m2 eine Umpolung statt, d. h. das Magnesium wird ursprünglich Anode zur Kathode. Versuche, bei denen die Massenverlustrate von Magnesium, hervorgerufen durch Wechselstromüberlagerung, bestimmt wurde, zeigten, daß bei Wechselstromdichten ab 20 A/m2 ein linear steigender Massenverlust von ungefähr 20 g pro Tag und m2 stattfindet.Für die Rohrleitungstechnik ergibt sich daraus, daß bei niederohmigem Boden und hohen induzierten Wechselspannungen eine Massenverlustrate auftritt, die bei der Auslegung der Anodengröße berücksichtigt werden muß.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 334 (1964), S. 15-20 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The precipitation of diphosphate from solutions of secondary alkali diphosphates by means of Ba2+ yields the acid salt Ba7H2P8O28·6H2O. With increasing alkalinity of the solutions, the hydrogen ion content of the Ba salt precipitate decreases. Precipitation from Na4-diphosphate solutions yields the neutral Ba2P2O7·1,5 H2O. From X-ray investigations (no structural differences between the two precipitates being found) it in concluded that the “neutral” Ba diphosphate has a phase range from Ba:H = 2:0 to 7:2.
    Notes: Ba2+ bildet-im Unterschied zu vielen anderen zweiwertigen Metallen-bei der Fällung aus Lösungen sekundärer Diphosphate ein saures Diphosphat, Ba7H2P8O28·6H2O. Mit steigender Alkalität der Fällungslösung nimmt die Acidität der Ba-Verbindung ab. Das neutrale Na-Diphosphat entsteht nur bei der Fällung aus quaternären Diphosphat-Lösungen. Bemerkenswerterweise besteht kein struktureller Unterschied zwischen den sauren Verbindungen und dem quaternären Salz, was zu der Annahme führt, daß das quaternäre Ba-Diphosphat eine Phasenbreite zwischen Ba:H = 2:0 und 7:2 besitzt.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 78 (1966), S. 551-552 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 5 (1966), S. 524-525 
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 7 (1968), S. 318-318 
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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