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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 259 (1981), S. 1003-1009 
    ISSN: 1435-1536
    Keywords: A flow ultramicroscope
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Die Arbeit stellt ein Gerät, geeignet für Teilchenzählung von einer Größenordnung bis 0.1 μm, vor. Es funktioniert auf Art eines Fließ-Ultramikroskops mit dem Unterschied, daß Teilchengrößenbestimmungen in dem Bereich von 0.1 bis 2.0 μm möglich sind, was mit anderen Geräten nicht der Fall ist. Die Teilchen fließen durch ein mit Laserlicht beleuchtetes Meßvolumen (Küvette). Das von ihnen gestreute Licht erzeugt Impulse, die mit Hilfe eines Photomultiplikators gezählt werden können. Die Intensität des von einem Teilchen gestreutes Licht hängt von dessen Größe ab und deshalb wird die Bestimmung einer Größenverteilung möglich. Die absolute Genauigkeit des Gerätes bestimmt man durch Vergleich mit einer engen Größenverteilung Polystyrol Latex. Ergebnisse zeigen, daß der Verlauf der Intensität in Abhängigkeit von Teilchengrößen mit der Theorie gut übereinstimmt.
    Notes: Summary A machine is described which will count particles or droplets in suspension in a liquid down to 0.1 μm and which is capable of size measurements between 0.1 μm and 2.0 ,μm. It works on the basis of the flow ultramicroscope. A stream of particles is passed through a laser beam and as each one passes a pulse of scattered light is produced. The pulses are detected by a photomultiplier and can be counted. Additionally the intensity of the pulses can be measured and a size distribution built up for the particles. The absolute accuracy of the machine has been checked by calibration against narrow size distribution polystyrene latexes and plots of intensity vs. size are found to conform with theory.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 10 (1981), S. 847-861 
    ISSN: 1572-8927
    Keywords: Single ion free energies of transfer ; tetraphenylarsonium tetraphenylboride assumption ; liquid junction potential assumption ; Ag+ ion ; acetonitrile ; dimethylsulfoxide ; dimethylformamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Free energies of transfer of ions from water to mixtures of water with acetonitrile (AN), with dimethylformamide (DMF), with dimethylsulfoxide (DMSO), and with ethylene glycol have been determined using both the tetraphenylarsonium tetraphenylboride [TATB] and the negligible liquid junction potential [E j ] assumptions. By making use of ΔG tr (Ag+)[TATB]=12 kJ-mol−1 for transfer from DMSO to AN and by assuming negligible liquid junction potential in the cell $${\text{Ag|AgNO}}_{\text{3}} {\text{(0}}{\text{.01}}M{\text{),S}}\parallel {\text{Et}}_{\text{4}} {\text{NPic(0}}{\text{.1}}M{\text{),AN}}\parallel {\text{AgNO}}_{\text{3}} {\text{(0}}{\text{.01}}M{\text{),AN|Ag}}$$ single ion free energies of transfer of silver ion ΔG tr (Ag+)[E j ] from DMSO to 35 pure and mixed solvents show a standard deviation of only 2 kJ-mol−1 when compared with ΔG tr (Ag+) calculated from the TATB assumption that ΔG tr (Ph 4 As+)=ΔG tr (Ph 4 B−). The ferrocene assumption [Fc] also gives acceptable agreement with ΔG tr (Ag+)[TATB] provided that the solvents are not highly aqueous. Other cells with other junctions give less acceptable agreement between the E j and TATB assumptions. It is essential that the salt bridge is always tetraethylammonium picrate in AN, if the E j assumption is assumed. Because of the ease of making potentiometric measurements compared with the difficulty of measurements required for the TATB assumption, the negligible liquid junction potential method in the cell shown is recommended for estimating transfer free energies of single ions. The ferrocene assumption is acceptable only for non-structured aprotic solvents.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 13 (1984), S. 103-119 
    ISSN: 1572-8927
    Keywords: Conductance ; Walden product ; tetraphenylarsonium and tetraphenylboride ions ; pyridine-water and acetonitrile-water mixtures ; alkali metal salts ; copper salts ; ion-solvent interactions ; structural effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The limiting conductance of various salts of Na+, Ag+, Cu+, Cu2+ and Ph4As+ in acetonitrile-water (AN-H2O) and pyridine-water (Py−H2O) mixtures are reported. Single ion values are calculated for AN-H2O mixtures using the TATB assumption [λo(Ph 4 As +) = λo(Ph 4 B −)]. The trends observed for the limiting Walden products (λoη) of the electrolytes and individual ions are discussed in terms of specific ion-solvent interactions and the structural effects of the solvent mixtures.
    Type of Medium: Electronic Resource
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