ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

The influence of the curvature dependence of the surface tension on the geometry of electrically charged menisci (1999)

dell'Erba, Ramiro ; dell'Isola, Francesco ; Rotoli, Giacomo

Springer

Continuum mechanics and thermodynamics 11 (1999), S. 89-105

add to mindlist on the mindlist

Details

ISSN: 1432-0959

Source: Springer Online Journal Archives 1860-2000

Topics: Physics

Notes: We evaluate how the curvature dependence of surface tension affects the shape of electrically charged interfaces between a perfectly conducting fluid and its vapour. We consider two cases: i) spherical droplets in equilibrium with their vapour; ii) menisci pending in a capillary tube in presence of a conducting plate at given electric potential drop. Tolman-like dependence of surface tension on curvature becomes important when the “nucleation radius” is comparable with the interface curvature radius. In case i) we prove existence of the equilibrium minimal radius and estimate its dependence on the electric fields and Tolman-like curvature effects. In case ii) the menisci are subject to the gravitational force, surface tension and electrostatic fields. We determine the unknown surface of the menisci to which the potential is assigned using an iterative numerical method and show that Tolman-like corrections imply: 1) a variation of the height (up to 10% in some cases) of the tip of the menisci; 2) a decrease of the maximum electrical potential applicable to the menisci before their break-down amounting to 40V over 800V in the considered cases. We conjecture that these effects could be used in new experiments based on electric measurements to determine the dependence of the equilibrium surface tension on curvature.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001610050105

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Steam-exploded wheat straw fibers as reinforcing material for polypropylene-based composites. Characterization and properties (1995)

Avella, Maurizio ; Bozzi, Claudio ; dell'Erba, Ramiro ; [et al.]

Weinheim : Wiley-Blackwell

Angewandte Makromolekulare Chemie 233 (1995), S. 149-166

add to mindlist on the mindlist

Details

ISSN: 0003-3146

Keywords: Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology , Physics

Description / Table of Contents: Aus Weizenstrohfasern und Polypropylen (iPP) bzw. mit Maleinsäureanhydrid modifiziertem Polypropylen (iPPMA) wurden Composite hergestellt. Die Weizenstrohfasern wurden vor dem Einmischen in die Polypropylenmatrix einem Dampfexplosionsprozeß unterworfen, der bei Lignocellulosematerialien morphologische und strukturelle Veränderungen bewirkt, die zu einer Verbesserung der Wechselwirkungen mit der thermoplastischen Matrix führen können. Die modifizierte iPPMA-Matrix weist im Vergleich zur iPP-Matrix bessere mechanische Eigenschaften (Zug- und Schlagverhalten) und eine bemerkenswerte Verringerung der Wasseraufnahme, einer der Hauptnachteile von Compositen mit Naturfasern, auf. Die gute Grenzflächenhaftung in den iPPMA-Compositen kann mit den beim Mischen der Fasern mit der Polymerschmelze gebildeten kovalenten Esterbindungen zwischen den Maleinsäureanhydrid-Segmenten und den dampfbehandelten Fasern erklärt werden.

Notes: Composites of wheat straw fibers with polypropylene (iPP) and maleic anhydride modified polypropylene (iPPMA) were prepared.Before being mixed with polypropylene matrices, the wheat straw fibers were subjected to a steam explosion process that induces morphological and structural changes in lignocellulosic materials. Such changes are able to enhance the interactions with the thermoplastic matrix.Compared with iPP, the modified matrix (iPPMA) has shown higher mechanical performances (tensile and impact behavior) and a remarkable decrease of water absorption, that is one of the main drawbacks of natural fiber composites.Finally, the presence of covalent bonds between maleic anhydride and steam-exploded (STEX) fibers, by means of an esterification reaction, produced during the melt-mixing process, can explain the resulting good interfacial adhesion found in iPPMA-based composities.

Additional Material: 11 Ill.