A new system for computer-aided preoperative planning and intraoperative navigation during corrective jaw surgery.

A new system for computer-aided corrective surgery of the jaws has been developed and introduced clinically. It combines three-dimensional (3-D) surgical planning with conventional dental occlusion planning. The developed software allows simulating the surgical correction on virtual 3-D models of the facial skeleton generated from computed tomography (CT) scans. Surgery planning and simulation include dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and segment repositioning. By coupling the software with a tracking system and with the help of a special registration procedure, we are able to acquire dental occlusion plans from plaster model mounts. Upon completion of the surgical plan, the setup is used to manufacture positioning splints for intraoperative guidance. The system provides further intraoperative assistance with the help of a display showing jaw positions and 3-D positioning guides updated in real time during the surgical procedure. The proposed approach offers the advantages of 3-D visualization and tracking technology without sacrificing long-proven cast-based techniques for dental occlusion evaluation. The system has been applied on one patient. Throughout this procedure, we have experienced improved assessment of pathology, increased precision, and augmented control.     

Charge Transfer Excitons in Polymer/Fullerene Blends: The Role of Morphology and Polymer Chain Conformation

Here, it is shown how carrier recombination through charge transfer excitons between conjugated polymers and fullerene molecules is mainly controlled by the intrachain conformation of the polymer, and to a limited extent by the mesoscopic morphology of the blend. This experimental result is obtained by combining near‐infrared photoluminescence spectroscopy and transmission electron microscopy, which are sensitive to charge transfer exciton emission and morphology, respectively. The photoluminescence intensity of the charge transfer exciton is correlated to the degree of intrachain order of the polymer, highlighting an important aspect for understanding and limiting carrier recombination in organic photovoltaics.     

3- and 4-Contact Point Spindle Bearings - a new Approach for High Speed Spindle Systems

One important demand on spindle systems in modem machine tools is to realise higher rotational speeds in order to increase the machining efficiency. In conventional spindle bearings the contact angles on inner and outer ring deviate extremely from one another with rising rotational speeds due to centrifugal forces. Axial shift of trie inner ring (elastic mounted bearing) and increasing normal forces in the contact zones on the outer ring are typical consequences leading to high internal bearing loads and a reduced life span. Based on these problems bearings with a new inner geometry are studied. Instead of two contact zones these bearings have three or four contact zones to ensure constant contact angles and reduced normal forces on the outer ring. In this paper analytic operation studies and first experimental tests are presented.     

Wann ist der Datenschutzbeauftragte fachkundig und unabhängig?

Der Datenschutzbeauftragte muss fachkundig und unabh?ngig sein, um seiner verantwortungsvollen Aufgabe im Unternehmen gerecht werden zu k?nnen. Rechtliche Grundlage hierfür ist § 4f BDSG, der die notwendigen Kompetenzen des Datenschutzbeauftragten festlegt. Die obersten Aufsichtsbeh?rden für den Datenschutz im nicht-?ffentlichen Bereich (=Düsseldorfer Kreis) haben vor noch nicht allzu langer Zeit hinsichtlich der Mindestanforderungen an Fachkunde und Unabh?ngigkeit einen Beschluss erlassen. Dieser beinhaltet wichtige Auslegungs- und Anwendungshinweise zu § 4f BDSG. Obwohl der Beschluss keine Gesetzeskraft hat, sollte er zur Vermeidung von Konflikten mit der zust?ndigen Landesaufsichtsbeh?rde beachtet werden. Anhand der Vorgaben von Aufsicht und Gesetz er?rtert der Aufsatz folgende Frage: Welche Konsequenzen kann der Beschluss für bereits bestellte Datenschutzbeauftragte haben? Und: Was sollte in der Zukunft bei der Neubestellung von Datenschutzbeauftragten beachtet werden?     

Platten aus Stahlbeton unter zweiaxialer Biegebeanspruchung

RC‐Members subjected to Biaxial Bending RC‐surface‐structures are usually subjected to multiaxial loadings e.g. in box girders at bridge construction, at two‐way slabs or also in area of load introduction of high loadings above and below columns. The design of these structures occurs presently with simplified assumptions, which is safe but not always the most economic solution. Superposition of single load cases or the addition of the amount of needed reinforcing steel may lead to overdimensioning of structures. Interactions, such as the effects of changing stiffness, receive no or an incomplete consideration. The non‐linear material behaviour is one essential reason for relocation of internal forces. This behaviour is caused by inhomogeneities, like the reinforcement. Within the framework of a research project and with experiences from tests with rc‐panels rc‐slabs with variable directions of reinforcement and under different bending moment ratios were investigated at the Institut für Konstruktiven Ingenieurbau of the University of the German Armed Forces Munich. The results of these tests should help to develop a simplified model to describe the observed behaviour.