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  • 1
    Electronic Resource
    Electronic Resource
    Urethral mobilization and meatal advancement: a surgical principle in hypospadias repair (1999)
    Springer
    Pediatric surgery international 15 (1999), S. 240-242 
    Details
    ISSN: 1437-9813
    Keywords: Key words Hypospadias ; Urethral mobilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A technique of urethral mobilization and advancement in hypospadias repair using the urethral elasticity to partially or completely bridge the defect in urethral length was employed in 56 children. In 46 with distal hypospadias it was the only procedure used. In 10 with proximal hypospadias, it was combined with other techniques. In distal hypospadias, no postoperative fistula occurred. Complications of the operation were 3 meatal stenoses that responded to dilatation, 1 urethral injury immediately repaired with no consequent fistula, and 1 chordee that was subsequently corrected. Of the 10 children with proximal hypospadias, 3 developed minor fistulae and 1 meatal stenosis. Urethral mobilization was found to be a safe and effective procedure in the management of hypospadias. It could be the only procedure required in distal hypospadias, or in combination with other procedures in proximal hypospadias.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003830050566
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  • 2
    Electronic Resource
    Electronic Resource
    The electrochemical behaviour of polycrystalline silver electrodes in Na2CO3 solution and the effect of ClO− 4 ions (1999)
    Springer
    Journal of solid state electrochemistry 3 (1999), S. 380-386 
    Details
    ISSN: 1433-0768
    Keywords: Key words Silver electrode ; Sodium carbonate ; Sodium perchlorate ; Pitting corrosion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The electrochemical behaviour of polycrystalline silver electrodes in Na2CO3 solutions was studied under potentiodynamic and potentiostatic conditions and complemented with X-ray diffraction analysis. Potentiodynamic E/i anodic curves exhibit active passive transition prior to an oxygen evolution reaction. The active region involves a small peak AI followed by a major peak AII before the passive region. Peak AI is assigned to the formation of an Ag2O layer while peak AII is due to the formation of an Ag2CO3 layer. The height of the anodic peaks increases with increasing Na2CO3 concentration, scan rate and temperature. The effect of increasing additions of NaClO4 on the electrochemical behaviour of Ag in Na2CO3 solutions was investigated. The perchlorate ions stimulate the active dissolution of Ag, presumably as a result of the formation of soluble AgClO4 salt. In the passive region, ClO− 4 ions tend to break down the dual passive film, leading to pitting corrosion at a certain critical pitting potential. The pitting potential decreases with ClO− 4 concentration. Potentiostatic current/time transients showed that the formation of Ag2O and Ag2CO3 layers involves a nucleation and growth mechanism under diffusion control. However, in the presence of ClO− 4 ions, the incubation time for pit initiation decreases on increasing the anodic potential step.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100080050170
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  • 3
    Electronic Resource
    Electronic Resource
    Electrochemical Behaviour of a Silver Electrode in NaOH Solutions (1998)
    Springer
    Monatshefte für Chemie 129 (1998), S. 1103-1117 
    Details
    ISSN: 1434-4475
    Keywords: Keywords. Cyclic voltammetry; Silver electrode; Alkaline solutions.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung.  Die Elektrochemie von Metallen und Legierungen stellt ein wichtiges Arbeitsgebiet in Forschung und Industrie dar. Die hier vorgestellte Untersuchung beinhaltet detaillierte Studien zur Korrosion und zum elektrochemischen Verhalten von Silber in wäßrigen Natriumhydroxidlösungen mittels cyclischer Voltammetrie, Chronoamperometrie und potentiostatischer Techniken. Die anodische Polarisationskurve von Ag in NaOH wird durch das Auftreten von fünf anodischen Peaks (A1–A5) charakterisiert. A1 resultiert aus der elektrochemischen Bildung von löslichen komplexen Species des Typs [Ag(OH)2]−, A2 aus jener von Ag2O, A3 geht auf Keimbildung und dreidimensionales Wachstum der Ag2O-Schicht zurück, A4 auf die Bildung von AgO, und A5 wird vermutlich durch die Bildung von Ag2O3 verursacht. Röntgendiffraktionsmuster bestätigen die Existenz passiver Ag2O- und AgO-Schichten an der Elektrodenoberfläche bei potentiodynamischer Polarisation bis zur Wasserstoffentwicklung. Der kathodische Teil der cyclischen Voltammogramme wird durch einen aktivierten anodischen Peak (A6, entsprechend der Elektrooxidation von Ag zu Ag2O) und drei kathodische Peaks (C1, C2, C2′, entsprechend der Elektroreduktion von AgO zu Ag2O und von Ag2O zu Ag) charakterisiert.
    Notes: Summary.  Studies of the electrochemistry of metals and alloys are very important fields of scientific and industrial work. The present investigation includes detailed studies on the corrosion and electrochemical behaviour of Ag in aqueous NaOH solutions under various conditions using cyclic voltammetry, chronoamperometry, and potentiostatic techniques. It was found that the anodic polarization curve of Ag in NaOH solutions is characterized by the occurrence of five anodic peaks (A1–A5). A1 is due to the electroformation of soluble [Ag(OH)2]− complex species, A2 to the electroformation of Ag2O, A3 to nucleation and three dimensional growth of the Ag2O layer, A4 to the formation of AgO, and A5 presumably to the formation of Ag2O3. X-ray diffraction patterns confirmed the existence of passive Ag2O and AgO layers on the electrode surface potentiodynamically polarized up to oxygen evolution. The cathodic part of the cyclic voltammograms is characterized by the occurrence of an activated anodic peak (A6) corresponding to the electrooxidation of Ag to Ag2O and three cathodic peaks (C1, C2, C2′) corresponding to the electroreduction of AgO to Ag2O and Ag2O to Ag, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00010123
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  • 4
    Electronic Resource
    Electronic Resource
    Perchlorate Pitting Corrosion of a Passivated Silver Electrode (1999)
    Springer
    Monatshefte für Chemie 130 (1999), S. 1207-1216 
    Details
    ISSN: 1434-4475
    Keywords: Keywords. Pitting corrosion; Silver anode; Perchlorate anion.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung.  Passivierung und Lochfraßkorrosion einer Silberelektrode in Natriumperchlorat enthaltenden Natriumhydroxidlösungen wurden mit potentiodynamischen und potentiostatischen Methoden untersucht. In perchloratfreier alkalischer Lösung zeigt das Voltammogramm vor Beginn der Sauerstoffentwicklung drei anodische Peaks. Die ersten beiden entsprechen der Oxidation von Ag und der Bildung einer passivierenden Ag2O-Schicht auf der Elektrodenoberfläche, der dritte einer Umwandlung von Ag2O in AgO. In Gegenwart von ClO4 − wurde eine ausgeprägte Abhängigkeit der Voltammogramme von der Perchloratkonzentration festgestellt. Durch die Anwesenheit von ClO4 − wird die Intensität der drei anodischen Peaks erhöht, und ab einem gewissen Potential bricht die Passivierung unter Eintreten von Lochfraßkorrosion zusammen. Das Lochfraßpotential nimmt linear mit der Konzentration von ClO4 − ab und steigt mit der Scangeschwindigkeit. Die potentiostatischen Strom/Zeit-Diagramme zeigen, daß die Lochfraßkorrosion als diffusionskontrolliertes dreidimensionales Wachstum charakterisiert werden kann.
    Notes: Summary.  The passivation and pitting breakdown of a silver electrode in sodium hydroxide solutions containing sodium perchlorate was studied using potentiodynamic and potentiostatic techniques. In perchlorate-free alkali solution, the voltammogram exhibits three anodic peaks prior to oxygen evolution. The first two peaks correspond to the oxidation of Ag and formation of a passive film of Ag2O on the electrode surface, the third to the conversion of Ag2O to AgO. In the presence of ClO4 −, the voltammogram depends considerably on perchlorate concentration. ClO4 − increases the height of the three anodic peaks, and at potentials above a limiting value breakdown of the anodic passivity and initiation of pitting corrosion occurs. The pitting potential decreases linearly with ClO4 − concentration but increases with scan rate. The potentiostatic current/time transients show that pitting corrosion can be described in terms of an instantaneous three dimensional growth under diffusion control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00010182
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  • 5
    Electronic Resource
    Electronic Resource
    Controlling Type II Error While Constructing Triple Sampling Fixed Precision Confidence Intervals for the Normal Mean (1997)
    Springer
    Annals of the Institute of Statistical Mathematics 49 (1997), S. 681-692 
    Details
    ISSN: 1572-9052
    Keywords: Coverage probability ; operating characteristic function ; optimal design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The rationale and methodology for estimating a mean with a fixed width confidence interval through sampling in three stages are extended to cover the additional problem of testing hypotheses concerning shifts in the mean with controlled Type II error. The coverage probability and operating characteristic function of the confidence interval based on the integrated approach are derived and compared with those of the usual triple sampling confidence interval. The extended methodology leads to better coverage probability and uniformly better Type II error probabilities. Achieving the additional objective of controlling Type II error inevitably implies a two- to threefold increase in the required optimal sample size. Some suggestions for dealing with this apparent limitation are discussed from a practical viewpoint. It is recommended that an integrated approach to estimation and testing based on confidence intervals be incorporated in the design stage for credible inferences.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003266326065
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  • 6
    Electronic Resource
    Electronic Resource
    Determination of trivalent antimony (1978)
    Springer
    Microchimica acta 69 (1978), S. 69-78 
    Details
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Eine Methode zur Bestimmung von Sb (III) wurde beschrieben. Sie beruht auf der Oxydation zu Sb(V) mit Permanganat in schwefelsaurer Lösung (0,72-3,4N H2SO4) in Gegenwart von Fluorid bei Temperaturen unter 50° C. Mengen zwischen 15,7gmg und 61 mg Antimon lassen sich genau bestimmen.
    Notes: Summary A method is described for the determination of trivalent antimony. It depends on the oxidation of Sb3+ to Sb+ with KMnO4 in sulfuric acid solutions (0.72-3.4N H2SO4) in the presence of fluoride ions and at temperatures below 50°. Amounts of antimony ranging from 15.7gmg to 61 mg can be determined accurately.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01196981
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  • 7
    Electronic Resource
    Electronic Resource
    Triple stage point estimation for the exponential location parameter (1988)
    Springer
    Annals of the Institute of Statistical Mathematics 40 (1988), S. 785-797 
    Details
    ISSN: 1572-9052
    Keywords: Two parameter (negative) exponential distribution ; minimum lifetime ; three-stage sampling ; regret ; Taylor expansion ; uniform integrability ; minimum risk ; bounded risk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract This paper deals with the problem of estimating the minimum lifetime (guarantee time) of the two parameter exponential distribution through a three-stage sampling procedure. Several forms of loss functions are considered. The regret associated with each loss function is determined. The results in this paper generalize the basic results of Hall (1981, Ann. Statist., 9, 1229–1238).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00049432
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  • 8
    Electronic Resource
    Electronic Resource
    Passivity and passivity breakdown of zinc anode in alkaline medium (1995)
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 46 (1995), S. 633-638 
    Details
    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: Passivität und Passivitätsverlust von Zinkanoden im alkalischen MediumDas elektrochemische Verhalten von Zink in NaOH-Lösungen wurde mittels potentiodynamischer Messungen und ergänzenden Röntgenanalysen untersucht. Die E/i-Kurven weisen vor der Sauerstoffentwicklung aktive, passive und transpassive Bereiche auf. Der aktive Bereich zeigt zwei anodische Maxima. Die Passivitat wird durch die Bildung eines kompakten Zn(OH)2-Films auf der Anodenoerfläche bewirkt. Der transpassive Bereich ist durch die Bildung von ZnO2 gekennzeichnet. Der Rücklauf zeigt ein anodisches Maximum sowie ein kathodisches Maximum vor der Wasserstoffentwicklung.Des weiteren wurde der Einfluß steigender Zugaben von NaCl, NaBr and Nal auf das anodische Verhalten von Zink in NaOH-Lösungen untersucht. Die Halogenide stimulieren die aktive Auflösung des Zinks und neigen daze, den Passivfilm zu zerstören, was zu Lochfraß führt. Die Aggressivität der Halogenidionen bezüglich der Stabilität des Passivfilms nimmt in der Reihenfolge I- 〉 Br- 〉 Cl- ab. Die Empfindlichkeit der Zinkanode erhöht sich mit zunehmender Halogenidionenkonzentration und sinkt sowohl mit steigender Alkalikonzentration als auch mit steigender Potentialänderungsgeschwindigkeit.
    Notes: The electrochemical behaviour of zinc in NaOH solutions has been investigated by using potentiodynamic technique and complemented by X-ray analysis. The E/i curves exhibit active, passive and transpassive regions prior to oxygen evolution. The active region displays two anodic peaks. The passivity is due to the Formation of a compact Zn(OH)2 film on the anode surface. The transpassive region is assigned to the electroformation of ZnO2. The reverse sweep shows an activation anodic peak and one catholic peak prior to hydrogen evolution.The influence of increasing additives of NaCl, NaBr and Nal on the anodic behaviour of zinc in NaOH solutions has been studied. The halides stimulate the active dissolution of zinc and tend to break down the passive film, leading to pitting corrosion. The aggressiveness of the halide anions towards the stability of the passive film decreases in the order: I- 〉 Br- 〉 Cl-. The susceptibility of zinc anode to pitting corrosion enhances with increasing the halide ion concentration but decreases with increasing both the alkali concentration and the sweep rate.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/maco.19950461105
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  • 9
    Electronic Resource
    Electronic Resource
    Electron-impact coherence parameters for the excitation of the 51 P state of Sr (1994)
    Springer
    The European physical journal 30 (1994), S. 91-97 
    Details
    ISSN: 1434-6079
    Keywords: 34.80.DP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Electron-photon polarization correlation measurements have been carried out for the excitation of the 51P state of Sr at electron impact energies of 30.3 and 58.4 eV and electron scattering angles of 20°–130° for 30.3 eV and 20°–100° for 58.4 eV. The resulting Stokes parametersP 1,P 2,P 3 are used to derive the usual complete scattering parameter sets λ, χ and γ,L ⊥,P l. New FOMBT calculations for these parameters are reported alongside the measured data and show substantial agreement with the experiment and with recent calculations by Srivastava et al.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01426055
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