A method for creating planar As2S3 waveguides with a minimum of processing steps is proposed, and the resulting waveguides have been characterized. When the processing parameters are optimized, the losses are low enough for practical use. The authors demonstrate this by creating serpentine waveguides with multiple bends and lengths in excess of 23cm. Keywords-component; chalcogenide glass; opti...

A ring R is called right א0-injective if every right homomorphism from a countably generated right ideal of R to RR can be extended to a homomorphism from RR to RR. In this note, some characterizations of א0-injective rings are given. It is proved that if R is semiperfect, then R is right א0injective if and only if every homomorphism from a countably generated small right ideal of R to RR can b...

Rapid Prototyping ist in der Industrie ein Fertigungsverfahren, bei dem ohne manuelle Umwege 3D-Modelle in Produkte umgesetzt werden. Nach mehr als 30 Jahren Industrieeinsatz ist dieses Verfahren mit dem 3D-Drucker auch für die Schule einsetzbar geworden. Die Schülerinnen und Schüler können alle Phasen der Modellerstellung und Modellumwandlung selbst gestalten und die einzelnen Arbeitsschritte ...

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Durch den Einsatz von Cochlea-Implantaten kann das Hörvermögen bei hochgradig schwerhörigen und tauben Patienten verbessert bzw. wiederhergestellt werden. Aufgrund eines zunehmenden Mangels an humanen Felsenbeinpräparaten kommen für das OP-Training künstliche, durch Rapid-Prototyping gefertigte Modelle zum Einsatz. Als Datengrundlage für das Rapid-Prototyping-Verfahren werden die CT-Schichtdate...

A parametric feature based jewelry modeler for designing and manufacturing of the Fret-worked bangles. These bangles are made from gold and adorned with fretwork designs. Fretwork is a decorative design that is either carved in low relief on a solid background, or cut out to adorn a jewelry item. Fretwork designs are viewed as features that are to be recurrently removed from the stock-solid ban...

Rapid manufacturing facilitated customization C. J. Tuck a , R. J. M. Hague a , M. Ruffo a , M. Ransley b & P. Adams b a Rapid Manufacturing Research Group , Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University , Loughborough, Leicestershire, LE11 3TU, UK b Martin Baker Aircraft Company Limited, Higher Denham , Uxbridge, Middlesex, UB9 5AJ, UK Published online: 25...

We provide necessary and sufficient conditions for admissible transformations in the projectivised dual quaternion model of rigid body displacements and we characterise constraint varieties of dyads with revolute and prismatic joints in this model. Projective transformations induced by coordinate changes in moving and/or fixed frame fix the quadrics of a pencil and preserve the two families of ...

As a step towards understanding the properties of string theory in time-dependent and singular spacetimes, we study the divergence of density operators for string ensembles in singular scale-invariant plane waves, i.e. those plane waves that arise as the Penrose limits of generic spacetime singularities. We show that the scale invariance implies that the Hagedorn behaviour of bosonic and supers...