Modes of Interaction in Computational Architecture

This thesis is an enquiry into the importance and influence of interaction in architecture, the importance of which is observed through different modes of interaction occurring in various aspects of architectural discourse and practice. Interaction is primarily observed through the different use of software within architectural practice and in the construction of buildings, façades and systems. In turn, the kind of influences software has on architecture is one of the underlying questions of this thesis. Four qualities: Concept, Materiality, Digitization and Interactivity, are proposed as a theoretical base for the analysis and assessment of different aspects of computational architecture. These four qualities permeate and connect the diverse areas of research discussed, including architecture, cybernetics, computer science, interaction design and new media studies, which in combination provide the theoretical background. The modalities of computational architecture analysed here are, digital interior spaces, digitized design processes and communicational exterior environments. The analysis is conducted through case studies: The Fun Palace, Generator Project, Water Pavilion, Tower of Winds, Institute du Monde Arabe, The KPN building, Aegis Hyposurface, BIX Façade, Galleria Department Store, Dexia Tower, and also E:cue, Microstation, Auto-Cad, Rhino, Top Solid and GenerativeComponents software. These are important for discussion because they present different architectural concepts and thoughts about interactivity within architecture. The analytical processes used in the research distinguished and refined, eight modes of interaction: (1) interaction as a participatory process; (2) cybernetic mutualism; (3) thematic interaction; (4) human-computer interaction during architectural design production; (5) interaction during digital fabrication; (6) parametric interaction; (7) kinetic interaction with dynamic architectural forms; and (8) interaction with façades. Out of these, cybernetic mutualism is the mode of interaction proposed by this thesis

Planar Cell Polarity Enables Posterior Localization of Nodal Cilia and Left-Right Axis Determination during Mouse and Xenopus Embryogenesis

Left-right asymmetry in vertebrates is initiated in an early embryonic structure called the ventral node in human and mouse, and the gastrocoel roof plate (GRP) in the frog. Within these structures, each epithelial cell bears a single motile cilium, and the concerted beating of these cilia produces a leftward fluid flow that is required to initiate left-right asymmetric gene expression. The leftward fluid flow is thought to result from the posterior tilt of the cilia, which protrude from near the posterior portion of each cell's apical surface. The cells, therefore, display a morphological planar polarization. Planar cell polarity (PCP) is manifested as the coordinated, polarized orientation of cells within epithelial sheets, or as directional cell migration and intercalation during convergent extension. A set of evolutionarily conserved proteins regulates PCP. Here, we provide evidence that vertebrate PCP proteins regulate planar polarity in the mouse ventral node and in the Xenopus gastrocoel roof plate. Asymmetric anterior localization of VANGL1 and PRICKLE2 (PK2) in mouse ventral node cells indicates that these cells are planar polarized by a conserved molecular mechanism. A weakly penetrant Vangl1 mutant phenotype suggests that compromised Vangl1 function may be associated with left-right laterality defects. Stronger functional evidence comes from the Xenopus GRP, where we show that perturbation of VANGL2 protein function disrupts the posterior localization of motile cilia that is required for leftward fluid flow, and causes aberrant expression of the left side-specific gene Nodal. The observation of anterior-posterior PCP in the mouse and in Xenopus embryonic organizers reflects a strong evolutionary conservation of this mechanism that is important for body plan determination

Planar Cell Polarity Signaling: The Developing Cell’s Compass

Cells of many tissues acquire cellular asymmetry to execute their physiologic functions. The planar cell polarity system, first characterized in Drosophila, is important for many of these events. Studies in Drosophila suggest that an upstream system breaks cellular symmetry by converting tissue gradients to subcellular asymmetry, whereas a downstream system amplifies subcellular asymmetry and communicates polarity between cells. In this review, we discuss apparent similarities and differences in the mechanism that controls PCP as it has been adapted to a broad variety of morphological cellular asymmetries in various organisms

Thermographic properties of Sm3+-doped GdVO4 phosphor

Rare-earth orthovanadates are important hosts for the luminescence of rare earth activators with considerable practical applications in the artificial production of light. In this paper we investigated the possibility for GdVO4:Sm3+ usage in phosphor thermometry by observing the temperature changes of trivalent samarium transitions from F-4(3/2) and (4)G(5/2) energy levels to the ground state. A set of three samples of Sm3+-doped GdVO4 (0.5, 1 and 2 mol.% Sm3+ with respect to Gd3+ ions) was produced via solid state synthesis. The sample crystalline structure is confirmed from x-ray diffraction (XRD) measurements. Photoluminescence measurements were recorded in the temperature range 293-823 K and the fluorescence intensity ratio of the paired emissions bands was studied as a function of temperature. All three GdVO4:Sm3+ samples proved to have good potential for the development of thermographic phosphors, whereas the maximum sensitivity of approximately 4.5x10(-4) K-1 was found for the sample with 2 mol.% Sm3+ in the temperature region around 750 K.3rd International School and Conference on Photonics, Aug 29-Sep 02, 2011, Belgrade, Serbi

Annealing effects on the microstructure and photoluminescence of Eu3+-doped GdVO4 powders

This work explores the influence of annealing temperature on microstructure and optical characteristics of Eu3+ doped GdVO4 (0.5, 1, 2 and 3 at.% Eu3+) nanopowders produced via co-precipitation synthesis. Samples were annealed at different temperatures (300 degrees C, 600 degrees C, 800 degrees C and 1000 degrees C) for 2 h and XRD analyses confirmed their tetragonal zircon structure. As-synthesized powders were composed of nanorods (diameter similar to 5 nm, length similar to 20 nm) organized in bundles, which by annealing grew to faceted crystals of round and rectangular shape (50-150 nm in size). Energy band gap shifts to higher energy (3.56 eV -> 3.72 eV) with decreasing crystallite size (43 nm -> 13 nm). Photoluminescence emission spectra were recorded using two different excitation wavelengths: lambda(ex) = 330 nm and lambda(ex) = 466 nm, aiming to excite directly the host matrix and Eu3+ ions, respectively. The intensity of most pronounced red transitions is one order of magnitude higher for lambda(ex) = 330 nm due to a strong energy absorption of VO43- groups, followed by efficient energy transfer to Eu3+ ions. We investigated the influence of annealing temperature and concentration of Eu3+ ions on the optical properties, namely photoluminescence emission and excitation, and decay time. The maximum intensity of D-5(0) -> F-7(2) red emission is observed for sample treated at 1000 degrees C, containing 2 at.% of Eu3+ ions. With the increase of Eu3+ concentration (0.5-3 at.%) the decay time of D-5(0) -> F-7(2) transition decreases from similar to 1 ms to 0.5 ms. (c) 2013 Elsevier B.V. All rights reserved