Seit einigen Jahren hat sich Mathcad als universelle Mathematiksoftware an vielen Universitäten, Instituten und in Unternehmen bewährt. An der Professur Maschinenelemente der TU Chemnitz wird Mathcad derzeit u.a. bei der Entwicklung einer vollkommen neuartigen Riemenscheibenkupplung für PKW-Kältemittelverdichter eingesetzt. Hierfür wurde ein mathematisches Modell entwickelt, mit dem sich die Bauteilbelastungen sowie die dynamischen Vorgänge in der Kupplung simulieren lassen. Bei der Analyse und Optimierung solcher technischen Systeme besteht häufig der Wunsch, die Bewegung der Bauteile und die wirkenden Kräfte direkt in Mathcad dreidimensional zu visualisieren, ohne dass dafür ein CAD-System benötigt wird. Im Vortrag werden benutzerfreundliche Funktionen präsentiert und anhand einiger Beispiele live vorgeführt, mit denen dies möglich ist. Des Weiteren wird gezeigt, wie diese Funktionen bei der Entwicklung der genannten Riemenscheibenkupplung eingesetzt wurden.

Zugl.: Berlin, Humboldt-Univ., Diss., 2006

Es werden effiziente Algorithmen vorgestellt, die auf algebraischen Methoden beruhen um die Unerfüllbarkeit aussagenlogischer 4-SAT Formeln zu zertifizieren. Die Algorithmen werden implementiert und auf praktische Weise hinsichtlich der Laufzeit mit Backtracking-Algorithmen verglichen.

Dieser Beitrag untersucht den Kontext der Berichterstattung über Politiker in deut- schen Hauptnachrichtensendungen vor der Bundestagswahl 2005. Dabei wird auf inhaltsanalytische Daten zurückgegriffen. Das zentrale Ergebnis der Studie ist, dass Politiker am häufigsten in Zusammenhang mit Wahl und Wahlkampf dargestellt werden. Es folgen Sachthemen und Eigenschaften der Politiker. Unpolitische Eigenschaften spielen gemessen an der gesamten Berichterstattung kaum eine Rolle. / This article analyzes the context in which German politicians are represented in German evening news before the parliamentary elections 2005. For this research project data from a content analysis is used. The conclusion is that in evening news politicians most frequently appear in the context of election and campaigning. Policies come second, the characteristics of politicians come third. Private characteristics are not important compared to the over-all.

Die Arbeit betrifft eine Untersuchung im Bereich des deutschen Markenrechts von 1874 bis 1994, nämlich die Wandlung des Begriffsinhalts der "Ärgernis erregenden Darstellung" als eines der Schutzhindernisse für die Markeneintragung. / The paper relates to a study in the field of German trademark law between 1874 and 1994, namely the change of the connotation of the "scandalous design" as one of the obstacles to protection of a trademark.

New materials can be fabricated using small scaled building blocks as a repetition unit. Nanoparticles with their unique size-tuneable properties from quantum confinement can especially be utilised to form two- and three-dimensional ordered assemblies to introduce them into what would normally be considered to be incompatible matrices. Furthermore, new collective properties that derive from the ordered arrangement of the building blocks, are accomplished. Additionally, different materials can be combined by mixing different building blocks during self-assembly, so that size ranges and material combinations that are difficult to achieve by other means can be formed. The arrangement of small particles into highly ordered arrangements can be realised via self-assembly. To achieve such assemblies, highly monodisperse nanoparticular building blocks with a size distribution below 5 % have to be synthesised. The production and variation in the size of both lead chalcogenide and noble metal nanoparticles is presented in this work. Moreover, the syntheses of multicomponential nanoparticles (PbSe/PbS and Au/PbS) are investigated. Non-classical crystallisation methodologies with their varyious self-assembly mechanisms are used for the formation of highly symmetrical mesocrystals and supracrystals. Analogous to classical crystallisation methods and their formation processes the interparticle interactions, attractive as well as repulsive, determine the resulting crystalline structure. Variation of the environmental parameters consequently leads to structural variation due to the changing interparticle interactions. In contrast to classical crystallisation the length scale of the interparticle forces stays constant as the size dimension of the self-assembled building unit is changed. Two different non-classical crystallisation pathways are investigated in this work. One pathway focuses on the slow destabilisation of nanoparticles in organic media by the addition of a non-solvent. In this approach optimisation of parameters for the formation of highly symmetrical three-dimensional mesostructures are studied. Furthermore, to shine some light onto the mechanism of self-assembly, the intrinsic arrangement of the building units in a mesocrystal and the steps of non-solvent addition are analysed. The mechanistic investigations explain the differences observed in mesocrystal formation between metal and semiconductor nanoparticles. The lower homogeneity of the building units of the metal nanoparticles leads to smaller and less defined superstructures in comparison to semiconductor building blocks. Another pathway of non-classical crystallisation is the usage of electrostatic interactions as the driving force for self-assembly and supracrystal formation. Therefore, the building blocks are transferred into aqueous media and stabilised with oppositely charged ligands. The well-know procedure for metal nanoparticles was adapted for semiconductor materials. The lower stability of these nanoparticles in aqueous solution induces an agglomeration of the semiconductor nanoparticles without including oppositely charged metal nanoparticles. The destabilisation effect can be increased by the addition of equally charged metal nanoparticles in a salting out type process. In comparison to the slow formation of mesocrystals achieved via destabilisation in an organic media (up to 4 weeks), the salting out procedure takes place within two hours, but the faster agglomeration causes a less well defined assembly of the building units in the mesocrystals. Moreover, the arrangement of semiconductor nanoparticles with organic molecules such as polymers and proteins was investigated in order to use the nanoparticles as a light harvesting component. In combination with the directly bound polymer the charge carrier may be directly transferred to the conductive thiophene-based polymer, so that infrared light can be transformed into an electrical signal for use in further applications such as solar cells. The advantage of the nanoparticle-protein system is the self-assembly across a liquid-liquid interface and additionally a Förster resonance energy transfer can occur at this phase boundary. Hence, it is possible to transfer highly energetic photons directly to biological samples without destroying the biological material.

Humboldt-Universiẗat, Diss.--Berlin, 2006. / Zusfassung in dt. und engl. Sprache.

Universiẗat, Diss.--Marburg, 2007. / Literaturverz. S. 213 - 259.

Zugl.: Duisburg, Essen, Universiẗat, Diss., 2008.

Zugl.: Bremen, Univ., Diss., 2008