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  • 2000-2004  (1)
  • 1990-1994  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 27 (1992), S. 5706-5712 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The inhibition effect of potassium iodide on the corrosion of stainless steel has been examined using weight loss and electrochemical measurements. Potassium iodide was found to be an excellent inhibitor for stainless steel types 316, 430 and 440 (efficiency more than 95%), and moderate for type 304. The corrosion rates in 1m HCl and in presence of potassium iodide fit an Arrhenius equation. The presence of potassium iodide lowered both the activation energy and the rate of reaction. Polarization measurements indicated that potassium iodide acts as an anodic inhibitor particularly at higher concentrations and as a cathodic inhibitor at lower concentrations. The synergistic effect of potassium iodide on the inhibitive efficiency of the organic substances was studied.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 6 (1993), S. 609-614 
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The kinetics of oxidation of p-aminodiphenylamine with the peroxydisulphate ion were investigated spectrophotometrically. The oxidation was accompanied by the appearance of a wine-red colour, which changed to become colourless. The reaction rate was measured by the stopped-flow technique with a UV spectrophotometer. The reactions proceeded with second-order kinetics, first-order for each individual reactant. Cationic micelles (cetyltrimethyl ammonium bromide) caused an enhancement in the reaction rate followed by inhibition at higher concentrations. Anionic micelles (sodium dodecyl sulphate), on the other hand, had a slightly retarding effect. The effects of radical scavenger, pH and ionic strength on the fast oxidation rate were examined. A mechanism consistent with the observations is discussed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1433-2965
    Keywords: Key words:Fracture – Manikin – Osteoporosis – Questionnaire – Validation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract: In population-based studies of osteoporosis, ascertainment of fractures is typically based on self-report, with subsequent verification by medical records. The aim of this analysis was to assess the validity of self-report of incident nonspine fractures using a postal questionnaire. The degree of overreporting of fracture (false positives) was assessed by comparing self-reports of new fracture from respondents in the multicenter European Prospective Osteoporosis Study with data from other sources including radiographs and medical records. In the analysis, 563 subjects reported nonspine fractures. Verification of the presence of fracture was possible in 510 subjects. Of these, fractures were not confirmed in 11% (false positives). The percentage of false positives was greater in men than in women (15% vs 9%, p=0.04), and less for fractures of the distal forearm and hip than for fractures at other sites. In a separate study, the degree of underreporting (false negatives) was assessed by follow-up of 251 individuals with confirmed fracture ascertained from the records of fracture clinics in three European centers (Lubeck, Oviedo, Warsaw). Questionnaire responses were received from 174 (69%) subjects. Of these, 12 (7%) did not recall sustaining a fracture (false negatives). The percentage of false negatives was lower for hip and distal forearm fractures with only 3 of 90 (3%) such fractures not recalled. Using the combined data from both studies, of those who reported a ‘date’ of fracture on the questionnaire, 91% of subjects were correct to within 1 month of the actual date of the fracture. A postal questionnaire is a relatively simple and accurate method for obtaining information about the occurrence of hip and distal forearm fractures, including their timing. Accuracy of ascertainment of fractures at other sites is less good and where possible self-reported fractures at such sites should be verified from other sources.
    Type of Medium: Electronic Resource
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