Wohnen bis ins Alter: Bauliche und organisatorische Voraussetzungen für lebenslanges Bewohnen von Baugemeinschaften

In der vorliegenden Arbeit wird der These nachgegangen, dass sich Baugemeinschaften als Wohnform, die von der Gemeinschaft und dem Zusammenleben geprägt ist, im Hinblick auf den demographischen Wandel und dessen Auswirkungen sich zum lebenslangen Bewohnen eignet. Untersucht wurden die baulichen und architektonischen, aber auch sozialen und organisatorischen Gegebenheiten am Beispiel 13 Dresdner Baugemeinschaften. Am Ende liegen Maßnahmen und Empfehlunen für künftige Bauherren und Planer vor.The present study traces the hypothesis that joint building ventures as a form of living, that is affected by the community and the cohabit, in view of the demographic change and its effects, are suit to lifelong occupancy. To be proved are the structural and architectural, but also the social and organizational conditions using the example of 13 joint building ventures in Dresden. Finally there are measures and recommendations for future building owners and architects on hand

Weiterbildungmonitoring - Berichtssystem Weiterbildung und Adult Education Survey als Datenbasis der Bildungsberichterstattung und der Bildungsforschung

Internationale und nationale Bildungsmonitorings sind inzwischen etablierte Elemente des Bildungssystems und die dort erhobenen Daten eine wichtige Referenz für Bildungspolitik und -forschung. Der Beitrag behandelt zunächst grundlegende Eigenschaften und Qualitätskriterien von Monitoringstudien und geht dann auf Spezifika des Monitorings von Weiterbildung ein. Anschließend werden das BSW und dessen Nachfolgestudie, der AES, als Datenbasis für ein Weiterbildungsmonitoring behandelt. Die konzeptionellen Unterschiede beider Studien und die Konsequenzen für eine Fortschreibung der Weiterbildungsberichterstattung im Rahmen des nationalen Bildungsberichts stehen im Mittelpunkt dieser Ausführungen

Nanotube Piezoelectricity

We combine ab initio, tight-binding methods and analytical theory to study piezoelectric effect of boron nitride nanotubes. We find that piezoelectricity of a heteropolar nanotube depends on its chirality and diameter and can be understood starting from the piezoelectric response of an isolated planar sheet, along with a structure specific mapping from the sheet onto the tube surface. We demonstrate that coupling between the uniaxial and shear deformation are only allowed in the nanotubes with lower chiral symmetry. Our study shows that piezoelectricity of nanotubes is fundamentally different from its counterpart in three dimensional (3D) bulk materials.Comment: 4 pages, with 3 postscript figures embedded. Uses REVTEX4 macros. Also available at http://www.physics.upenn.edu/~nsai/preprints/bn_piezo/index.htm

Stochastic Heterostructures in B/N-Doped Carbon Nanotubes

Carbon nanotubes are one-dimensional and very narrow. These obvious facts imply that under doping with boron and nitrogen, microscopic doping inhomogeneity is much more important than for bulk semiconductors. We consider the possibility of exploiting such fluctuations to create interesting devices. Using self-consistent tight-binding (SCTB), we study heavily doped highly compensated nanotubes, revealing the spontaneous formation of structures resembling chains of random quantum dots, or nano-scale diode-like elements in series. We also consider truly isolated impurities, revealing simple scaling properties of bound state sizes and energies.Comment: 4 pages RevTeX, 4 PostScript figure

Modeling the series of (n x 2) Si-rich reconstructions of beta-SiC(001): a prospective atomic wire?

We perform ab initio plane wave supercell density functional calculations on three candidate models of the (3 x 2) reconstruction of the beta-SiC(001) surface. We find that the two-adlayer asymmetric-dimer model (TAADM) is unambiguously favored for all reasonable values of Si chemical potential. We then use structures derived from the TAADM parent to model the silicon lines that are observed when the (3 x 2) reconstruction is annealed (the (n x 2) series of reconstructions), using a tight-binding method. We find that as we increase n, and so separate the lines, a structural transition occurs in which the top addimer of the line flattens. We also find that associated with the separation of the lines is a large decrease in the HOMO-LUMO gap, and that the HOMO state becomes quasi-one-dimensional. These properties are qualititatively and quantitatively different from the electronic properties of the original (3 x 2) reconstruction.Comment: 22 pages, including 6 EPS figure

Graphene allotropes: stability, structural and electronic properties from DF-TB calculations

Using the density-functional-based tight-binding method we performed a systematic comparative study of stability, structural and electronic properties for 12 various types of graphene allotropes, which are likely candidates for engineering of novel graphene-like materials.Comment: 12 pages, 4 figure

Vibrational properties of single-wall nanotubes and monolayers of hexagonal BN

We report a detailed study of the vibrational properties of BN single-walled nanotubes and of the BN monolayer. Our results have been obtained from a well-established Tight-Binding model complemented with an electrostatic model to account for the long-range interactions arising from the polar nature of the material, and which are not included in the Tight-Binding model. Our study provides a wealth of data for the BN monolayer and nanotubes, such as phonon band structure, vibrational density of states, elastic constants, etc. For the nanotubes we obtain the behavior of the optically active modes as a function of the structural parameters, and we compare their frequencies with those derived from a zone-folding treatment applied to the phonon frequencies of the BN monolayer, finding general good agreement between the two.Comment: 14 pages with 10 postscript figures, to appear in PRB, January 15th 200

Wohnen bis ins Alter: Bauliche und organisatorische Voraussetzungen für lebenslanges Bewohnen von Baugemeinschaften

In der vorliegenden Arbeit wird der These nachgegangen, dass sich Baugemeinschaften als Wohnform, die von der Gemeinschaft und dem Zusammenleben geprägt ist, im Hinblick auf den demographischen Wandel und dessen Auswirkungen sich zum lebenslangen Bewohnen eignet. Untersucht wurden die baulichen und architektonischen, aber auch sozialen und organisatorischen Gegebenheiten am Beispiel 13 Dresdner Baugemeinschaften. Am Ende liegen Maßnahmen und Empfehlunen für künftige Bauherren und Planer vor.The present study traces the hypothesis that joint building ventures as a form of living, that is affected by the community and the cohabit, in view of the demographic change and its effects, are suit to lifelong occupancy. To be proved are the structural and architectural, but also the social and organizational conditions using the example of 13 joint building ventures in Dresden. Finally there are measures and recommendations for future building owners and architects on hand